The location of the blades. Optimal blades for a wind generator: type, shape, materials and DIY instructions

We have developed a design of a wind turbine with a vertical axis of rotation. Below is a detailed guide for its manufacture, carefully reading which, you can make a vertical wind generator yourself.
The wind generator turned out to be quite reliable, with low maintenance costs, inexpensive and easy to manufacture. It is not necessary to follow the list of details below, you can make some adjustments of your own, improve something, use your own, because. Not everywhere you can find exactly what is on the list. We tried to use inexpensive and high-quality parts.

Used materials and equipment:

Name	Qty	Note
List of used parts and materials for the rotor:
Pre-cut metal sheet	1	Cut from 1/4" thick steel using waterjet, laser, etc. cutting
Hub from car (Hub)	1	Should contain 4 holes, about 4 inches in diameter
2" x 1" x 1/2" neodymium magnet	26	Very fragile, it is better to order additionally
1/2"-13tpi x 3" stud	1	TPI - number of threads per inch
1/2" nut	16
1/2" washer	16
1/2" grower	16
1/2".-13tpi cap nut	16
1" washer	4	In order to maintain the gap between the rotors

List of used parts and materials for the turbine:
3" x 60" Galvanized pipe	6
ABS plastic 3/8" (1.2x1.2m)	1
Balancing magnets	If needed	If the blades are not balanced, then the magnets are attached to balance
1/4" screw	48
1/4" washer	48
1/4" grower	48
1/4" nut	48
2" x 5/8" corners	24
1" corners	12 (optional)	If the blades do not hold their shape, then you can add extra. corners
screws, nuts, washers and grovers for 1" angle	12 (optional)

List of used parts and materials for the stator:
Epoxy with hardener	2 l
1/4" screw st.	3
1/4" washer st.	3
1/4" nut ss.	3
1/4" ring tip	3	For e-mail connections
1/2"-13tpi x 3" stud st.	1	stainless steel steel is not a ferromagnet, so it will not "brake" the rotor
1/2" nut	6
fiberglass	If needed
0.51mm enamel. the wire		24AWG

List of used parts and materials for installation:
1/4" x 3/4" bolt	6
1-1/4" pipe flange	1
1-1/4" galvanized pipe L-18"	1

Tools and equipment:
1/2"-13tpi x 36" stud	2	Used for jacking
1/2" bolt	8
Anemometer	If needed
1" aluminum sheet	1	For making spacers if needed
green paint	1	For painting plastic holders. Color is not important
Blue paint ball.	1	For painting the rotor and other parts. Color is not important
multimeter	1
Soldering iron and solder	1
Drill	1
Hacksaw	1
Kern	1
Mask	1
Protective glasses	1
Gloves	1

Wind turbines with a vertical axis of rotation are not as efficient as their horizontal counterparts, however, vertical wind turbines are less demanding on their installation site.

Turbine manufacturing

1. Connecting element - designed to connect the rotor to the wind turbine blades.
2. The layout of the blades - two opposite equilateral triangles. According to this drawing, it will then be easier to arrange the corners of the blades.

If you are not sure about something, cardboard templates will help you avoid mistakes and further alterations.

The sequence of steps for manufacturing a turbine:

Production of the lower and upper supports (bases) of the blades. Mark and use a jigsaw to cut out a circle from ABS plastic. Then circle it and cut out the second support. You should get two absolutely identical circles.
In the center of one support, cut a hole with a diameter of 30 cm. This will be the top support of the blades.
Take the hub (hub from the car) and mark and drill four holes on the bottom support for attaching the hub.
Make a template for the location of the blades (fig. above) and mark on the lower support the attachment points for the corners that will connect the support and the blades.
Stack the blades, tie them tightly and cut to the desired length. In this design, the blades are 116 cm long. The longer the blades, the more wind energy they receive, but the downside is instability in strong winds.
Mark the blades for attaching the corners. Pierce and then drill holes in them.
Using the paddle pattern shown in the picture above, attach the paddles to the support with the brackets.

Rotor manufacturing

The sequence of actions for the manufacture of the rotor:

Lay the two rotor bases on top of each other, align the holes and make a small mark on the sides with a file or marker. In the future, this will help to correctly orient them relative to each other.
Make two paper magnet placement templates and glue them to the bases.
Mark the polarity of all magnets with a marker. As a "polarity tester" you can use a small magnet wrapped in a rag or electrical tape. By passing it over a large magnet, it will be clearly visible whether it is repelled or attracted.
Prepare epoxy resin (by adding hardener to it). And apply it evenly on the bottom of the magnet.
Very carefully bring the magnet to the edge of the rotor base and move it to its position. If the magnet is installed on top of the rotor, then the high power of the magnet can sharply magnetize it and it can break. And never stick your fingers or other body parts between two magnets or a magnet and iron. Neodymium magnets are very powerful!
Continue gluing the magnets to the rotor (do not forget to lubricate with epoxy), alternating their poles. If the magnets move under the influence of magnetic force, then use a piece of wood, placing it between them for insurance.
After one rotor is finished, move on to the second. Using the mark you made earlier, position the magnets exactly opposite the first rotor, but in a different polarity.
Put the rotors away from each other (so that they do not get magnetized, otherwise you will not pull it off later).

The manufacture of a stator is a very laborious process. Of course, you can buy a ready-made stator (try to find them with us) or a generator, but it’s not a fact that they are suitable for a particular windmill with their own individual characteristics.

The wind generator stator is an electrical component consisting of 9 coils. The stator coil is shown in the photo above. The coils are divided into 3 groups, 3 coils in each group. Each coil is wound with 24AWG (0.51mm) wire and contains 320 turns. More turns but thinner wire will give higher voltage but less current. Therefore, the parameters of the coils can be changed, depending on what voltage you require at the output of the wind generator. The following table will help you decide:
320 turns, 0.51mm (24AWG) = 100V @ 120 rpm.
160 turns, 0.0508mm (16AWG) = 48V @ 140 rpm.
60 turns, 0.0571 mm (15AWG) = 24V @ 120 rpm.

Winding coils by hand is a boring and difficult task. Therefore, in order to facilitate the winding process, I would advise you to make a simple device - a winding machine. Moreover, its design is quite simple and it can be made from improvised materials.

The turns of all coils should be wound in the same way, in the same direction, and pay attention or mark where the beginning and where the end of the coil is. To prevent unwinding of the coils, they are wrapped with electrical tape and smeared with epoxy.

The fixture is made from two pieces of plywood, a bent hairpin, a piece of PVC pipe and nails. Before bending the hairpin, heat it with a torch.

A small piece of pipe between the planks provides the desired thickness, and four nails provide the required dimensions for the coils.

You can come up with your own design of the winding machine, or maybe you already have a ready-made one.
After all the coils are wound, they must be checked for identity to each other. This can be done using scales, and you also need to measure the resistance of the coils with a multimeter.

Do not connect household consumers directly from the wind turbine! Also observe the safety precautions when handling electricity!

Coil connection process:

Sand the ends of the leads on each coil.
Connect the coils as shown in the picture above. You should get 3 groups, 3 coils in each group. With this connection scheme, a three-phase alternating current will be obtained. Solder the ends of the coils, or use clamps.
Choose from the following configurations:
A. Configuration" star". In order to get a large output voltage, connect the X, Y and Z pins together.
B. Delta configuration. To get a high current, connect X to B, Y to C, Z to A.
C. In order to make it possible to change the configuration in the future, grow all six conductors and bring them out.
On a large sheet of paper, draw a diagram of the location and connection of the coils. All coils must be evenly distributed and match the location of the rotor magnets.
Attach the spools with tape to the paper. Prepare epoxy resin with hardener for casting the stator.
Use a paint brush to apply epoxy to fiberglass. If necessary, add small pieces of fiberglass. Do not fill the center of the coils to ensure sufficient cooling during operation. Try to avoid the formation of bubbles. The purpose of this operation is to secure the coils in place and flatten the stator, which will be located between the two rotors. The stator will not be a loaded node and will not rotate.

In order to make it more clear, consider the whole process in pictures:

The finished coils are placed on waxed paper with the layout drawn. Three small circles in the corners in the photo above are the holes for mounting the stator bracket. The ring in the center prevents the epoxy from getting into the center circle.

The coils are fixed in place. Fiberglass, in small pieces, is placed around the coils. The coil leads can be brought inside or outside the stator. Be sure to leave enough lead length. Be sure to double-check all connections and ring with a multimeter.

The stator is almost ready. The holes for mounting the bracket are drilled in the stator. When drilling holes, be careful not to hit the coil leads. After completing the operation, cut off the excess fiberglass and, if necessary, clean the surface of the stator with sandpaper.

stator bracket

The pipe for attaching the hub axle was cut to the desired size. Holes were drilled and threaded in it. In the future, bolts will be screwed into them that will hold the axle.

The figure above shows the bracket to which the stator will be attached, located between the two rotors.

The photo above shows a stud with nuts and a sleeve. Four of these studs provide the necessary clearance between the rotors. Instead of a bushing, you can use larger nuts, or cut your own aluminum washers.

Generator. final assembly

A small clarification: a small air gap between the rotor-stator-rotor connection (which is set by a stud with a bushing) provides a higher power output, but the risk of damage to the stator or rotor increases when the axis is misaligned, which can occur in strong winds.

The left picture below shows a rotor with 4 clearance studs and two aluminum plates (which will be removed later).
The right picture shows the assembled and green painted stator in place.

Assembly process:
1. Drill 4 holes in the top rotor plate and thread them for the stud. This is necessary to smoothly lower the rotor into place. Rest 4 studs in the aluminum plates glued earlier and install the top rotor on the studs.
The rotors will be attracted to each other with a very large force, which is why such a device is needed. Immediately align the rotors relative to each other according to the marks on the ends set earlier.
2-4. Alternately rotating the studs with a wrench, evenly lower the rotor.
5. Once the rotor has rested against the hub (providing clearance), unscrew the studs and remove the aluminum plates.
6. Install the hub (hub) and screw it on.

The generator is ready!

After installing the studs (1) and the flange (2), your generator should look something like this (see the figure above)

Stainless steel bolts serve to provide electrical contact. It is convenient to use ring lugs on wires.

Cap nuts and washers are used to fasten the connections. boards and blade supports to the generator. So, the wind generator is fully assembled and ready for tests.

To begin with, it is best to spin the windmill with your hand and measure the parameters. If all three output terminals are shorted together, then the windmill should rotate very tightly. This can be used to stop the wind turbine for service or safety reasons.

A wind turbine can be used for more than just providing electricity to your home. For example, this instance is made so that the stator generates a large voltage, which is then used for heating.
The generator considered above produces a 3-phase voltage with different frequencies (depending on the strength of the wind), and for example, in Russia a single-phase 220-230V network is used, with a fixed network frequency of 50 Hz. This does not mean that this generator is not suitable for powering household appliances. Alternating current from this generator can be converted to direct current, with a fixed voltage. And direct current can already be used to power lamps, heat water, charge batteries, and can be supplied to convert direct current into alternating current. But this is already beyond the scope of this article.

In the figure above, a simple circuit of a bridge rectifier, consisting of 6 diodes. It converts AC to DC.

Location of the wind generator

The wind generator described here is mounted on a 4-meter support on the edge of a mountain. The pipe flange, which is installed at the bottom of the generator, provides an easy and quick installation of the wind generator - it is enough to fasten 4 bolts. Although for reliability, it is better to weld.

Usually, horizontal wind turbines "like" when the wind blows from one direction, unlike vertical wind turbines, where due to the weather vane, they can turn and they do not care about the direction of the wind. Because Since this windmill is installed on the shore of a cliff, the wind there creates turbulent flows from different directions, which is not very effective for this design.

Another factor to consider when choosing a location is the strength of the wind. An archive of wind strength data for your area can be found on the Internet, although this will be very approximate, because. it all depends on the location.
Also, an anemometer (a device for measuring wind force) will help in choosing the location of the installation of the wind generator.

A little about the mechanics of the wind generator

As you know, the wind occurs due to the difference in temperature of the earth's surface. When the wind rotates the turbines of a wind generator, it creates three forces: lifting, braking and impulse. The lifting force usually occurs over a convex surface and is a consequence of the pressure difference. The wind braking force occurs behind the blades of the wind generator, it is undesirable and slows down the windmill. The impulse force comes from the curved shape of the blades. When the air molecules push the blades from behind, then they have nowhere to go and they gather behind them. As a result, they push the blades in the direction of the wind. The greater the lifting and impulse forces and the less braking force, the faster the blades will rotate. Accordingly, the rotor rotates, which creates a magnetic field on the stator. As a result, electrical energy is generated.

The main rotor blades of a helicopter must be built in such a way that they, creating the necessary lifting force, can withstand all the loads that arise on them. And they didn’t just withstand, but would still have a margin of safety for all sorts of unforeseen cases that may occur in flight and during maintenance of the helicopter on the ground (for example, a sharp gust of wind, an updraft of air, a sharp maneuver, icing of the blades, inept spin-up of the propeller after launch engine, etc.).

One of the design modes for selecting the main rotor of a helicopter is the mode of vertical climb at any height chosen for the calculation. In this mode, due to the lack of translational speed in the plane of rotation of the propeller, the required power is large.

Knowing the approximate weight of the helicopter being designed and setting the payload that the helicopter will have to lift, they begin to select the propeller. The selection of the propeller is reduced to choosing such a diameter of the propeller and such a number of its revolutions per minute, at which the calculated load could be lifted by the propeller vertically upwards with the least expenditure of power.

At the same time, it is known that the thrust of the main rotor is proportional to the fourth power of its diameter and only to the second power of the number of revolutions, that is, the thrust developed by the main rotor depends more on the diameter than on the number of revolutions. Therefore, a given thrust is easier to obtain by increasing the diameter than by increasing the number of revolutions. So, for example, by increasing the diameter by 2 times, we get 24 = 16 times more thrust, and by doubling the number of revolutions, we get only 22 = 4 times more thrust.

Knowing the power of the engine that will be installed on the helicopter to drive the main rotor, first select the diameter of the main rotor. For this, the following ratio is used:

The main rotor blade works in very difficult conditions. Aerodynamic forces act on it, which bend it, twist it, tear it, and tend to tear off the skin from it. To "resist" such an action of aerodynamic forces, the blade must be strong enough.

When flying in rain, snow or clouds under icing conditions, the operation of the blade is even more complicated. Raindrops, falling on the blade with enormous speeds, knock off the paint from it. When icing occurs on the blades, ice growths form, which distort its profile, interfere with its flapping motion, and make it heavier. When storing a helicopter on the ground, sharp changes in temperature, humidity, and sun rays are destructive to the blade.

This means that the blade must not only be strong, but it must also be immune to the influence of the external environment. But if only this! Then the blade could be made all-metal, covering it with an anti-corrosion layer, and the problem would be solved.

But there is one more requirement: the blade, in addition, must also be light. Therefore, it is made hollow. A metal spar is taken as the basis for the design of the blade, most often a steel pipe of variable cross section, the area of \u200b\u200bwhich gradually or stepwise decreases from the root to the end of the blade.

The spar, as the main longitudinal power element of the blade, perceives the cutting forces and the bending moment. In this respect, the operation of a blade spar is similar to that of an aircraft wing spar. However, centrifugal forces still act on the spar of the blades as a result of the rotation of the propeller, which is not the case with the wing spar of the aircraft. Under the action of these forces, the spar of the blade is subjected to tension.

Steel flanges are welded or riveted to the spar for fastening the transverse power set - the ribs of the blade. Each rib, which can be metal or wood, consists of walls and shelves. Metal sheathing is glued or welded to metal shelves, and plywood sheathing or canvas sheathing is glued to wooden shelves, or plywood sheathing is glued to the toe and linen sheathing is sewn to the tail, as shown. In the forward part of the profile, the rib flanges are attached to the front stringer, and in the tail part - to the rear stringer. Stringers serve as auxiliary longitudinal power elements.

The skin covering the shelves of the ribs forms the profile of the blade in any of its sections. The lightest is linen sheathing. However, in order to avoid distortion of the profile as a result of the deflection of the fabric sheathing in the areas between the ribs, the ribs of the blade have to be installed very often, approximately 5-6 cm from one another, which makes the blade heavier. The surface of the blade with a poorly stretched fabric sheathing looks ribbed and has low aerodynamic qualities, since its drag is high. During one revolution, the profile of such a blade changes, which contributes to the appearance of additional vibration of the helicopter. Therefore, the linen sheathing is impregnated with dope, which, as it dries, strongly stretches the canvas.

In the manufacture of plywood sheathing, the rigidity of the blade increases and the distance between the ribs can be increased by a factor of 2.5 compared to blades covered with canvas. In order to reduce drag, the surface of the plywood is smoothly machined and polished.

Good aerodynamic shapes and high strength can be achieved if a hollow all-metal blade is made. The difficulty of its production lies in the manufacture of a variable cross-section of the spar, which forms the bow of the profile. The tail part of the blade profile is made of sheet metal sheathing, which is welded flush to the spar with the leading edges, and the trailing edges are riveted together.

The profile of the helicopter propeller blade is selected in such a way that, with an increase in the angle of attack, the flow stall occurs at the highest possible angles of attack. This is necessary in order to avoid flow stall on the retreating blade, where the angles of attack are especially high. In addition, in order to avoid vibrations, the profile must be selected such that, when the angle of attack changes, the position of the center of pressure does not change.

A very important factor for the strength and operation of the blade is the relative position of the center of pressure and the center of gravity of the profile. The fact is that with the combined action of bending and torsion, the blade is subject to self-excited vibration, i.e., vibration with an ever-increasing amplitude (flutter). In order to avoid vibration, the blade must be balanced relative to the chord, i.e., such a position of the center of gravity on the chord must be ensured that would exclude self-increase of vibration. The task of balancing is to ensure that the center of gravity of the profile of the constructed blade is in front of the center of pressure.

Continuing to consider the harsh operating conditions of the main rotor blade, it should be noted that damage to the wooden sheathing of the blade by raindrops can be prevented if a sheet metal edging is strengthened along its leading edge.

The fight against icing of the blades is a more difficult task. If such types of icing in flight as hoarfrost and hoarfrost do not pose a great danger to a helicopter, then vitreous ice, gradually and imperceptibly, but extremely firmly building up on the blade, leads to weighting of the blade, distortion of its profile and, ultimately, to a decrease in lifting force, which leads to a sharp loss of controllability and stability of the helicopter.

The theory that existed at one time that the ice would break off in flight due to the flapping movement of the blades turned out to be untenable. The icing of the blade begins first of all at the root part, where the bending of the blade during its flapping motion is small. In the future, the ice layer begins to spread further and further towards the end of the blade, gradually fading away. There are cases when the ice thickness at the root part reached 6 mm, and at the end of the blade - 2 mm.

Ice formation can be prevented in two ways.

First way- this is a thorough study of the weather forecast in the area of flights, bypassing the clouds encountered along the way and changing the flight altitude in order to get out of icing, stopping the flight, etc.

Second way- this is the equipment of the blades with anti-icing devices.

A number of these devices for helicopter blades are known. To remove ice from the rotor blades,

alcohol de-icer should be applied, which sprays alcohol on the leading edge of the propeller. The latter, mixing with water, lowers its freezing point and prevents the formation of ice.

The chipping of ice from the propeller blades can be carried out by air, which is injected into a rubber chamber laid along the leading edge of the main rotor. The inflating chamber pierces the ice crust, individual pieces of which are then swept away from the propeller blades by the oncoming air flow.

If the leading edge of the propeller blade is made of metal, then it can be heated either by electricity or by warm air passed through a pipeline running along the leading edge of the rotor.

The future will show which of these methods will be more widely used.

For the aerodynamic characteristics of the main rotor, the number of main rotor blades and the specific load on the area swept by the propeller are of great importance. Theoretically, the number of propeller blades can be anything, from one infinitely large number of them, so large that they eventually merge into a spiral surface, as was assumed in the project of Leonardo da Vinci or in I. Bykov's helicopter-bicycle.

However, there is some most advantageous number of blades. The number of blades should not be less than three, since with two blades large unbalanced forces and fluctuations in propeller thrust occur. The change in the main rotor thrust is shown around its average value during one revolution of the rotor for single-blade and two-blade propellers. The three-blade propeller already practically maintains the average value of thrust throughout the entire revolution.

The number of propeller blades should also not be very large, since in this case each blade operates in a flow disturbed by the previous blade, which reduces the efficiency of the main rotor.

The more propeller blades, the greater part of the swept disk area they occupy. The concept of the fill factor o was introduced into the theory of the helicopter rotor, which is calculated as the ratio of the total area

For the design mode of operation of the main rotor of the helicopter (steep rise), the most advantageous value of the fill factor is 0.05-0.08 (average value 0.065).

This load is average. A small load is a load in the range of 9-12 kg / m2. Helicopters with such a load are maneuverable and have a high cruising speed.

General purpose helicopters have an average load ranging from 12 to 20 kg/m2. And finally, a large load, rarely used, is a load of 20 to 30 kg / m2.

The fact is that although a high specific load on the swept area provides a large payload of the helicopter, but in the event of an engine failure, such a helicopter in the self-rotation mode will decrease quickly, which is unacceptable, since in this case the safety of descent is violated.

searching results

Found results: 122140 (1.75 sec)

Free access

Limited access

License renewal is being specified

Methods of physical and mathematical modeling method. instructions for the implementation of individual tasks

Tasks for practical classes in the discipline "Methods of physical and mathematical modeling" are given, which contribute to the acquisition of skills in developing algorithms, drawing up flowcharts, programming and working on a computer (program input, its debugging).

the specified format to the display" LPRINT USING"output numerical variables in the specified format to print" TAB "location<...>performing an operation or group of operations that changes a value, presentation, or location<...>paper Off-page connector indication of the connection between the disconnected parts of the schemes of program algorithms located

Preview: Methods of physical and mathematical modeling.pdf (0.1 Mb)

RESEARCH OF THE WORK OF A THREE-TIER PLOW ABSTRACT DIS. ... CANDIDATE OF TECHNICAL SCIENCES

SARATOV INSTITUTE OF AGRICULTURAL MECHANIZATION NAMED AFTER M. I. KALININ

Experimental studies have confirmed the theoretical conclusions drawn from the assumption that the traction force always passes through the centers of resistance of the plow in the horizontal and vertical planes.

year wrote: "The location of the resistance H (formation resistance) and seed | N (reaction on the field board)<...>Rxz»» located at a height equal to half the plowing depth from the toes of the corresponding shares.<...>On the transverse bars, with the help of plumb lines, the points of the rib of the dynamo located above the bars were projected.

Preview: STUDY OF THE WORK OF A THREE-TIER PLOW.pdf (0.0 Mb)

#9 [System Administrator, 2016]

System Administrator magazine is the leading Russian industry publication for IT professionals. Its goal is to provide complete and objective information about the solutions, products and technologies of the modern IT industry. 90% of the articles in the journal are of an applied nature, provided with examples, tables, and graphic material. That is why the System Administrator magazine is a desktop guide for IT professionals and those who decide to pursue a career in IT. Published since October 2002.

----------# Variables #-------------# wiki directory base=/home/user/site1 # location<...>directory with MediaWiki engine files, ↵ optional, default = "$mw"" echo "" echo "Location<...>In such cases, the antivirus located at the second level of static analysis, checking the incoming message<...>which includes five components: Dial Plan, Voice Policy, Route, PSTN Usage, Trunk Configuration, located<...>The second> step is to create a "replacement request" that is identical in text to the original one (with the same location

Preview: System Administrator No. 9 2016.pdf (0.3 Mb)

Multi-agent technology for managing mobile resources in real time. allowance

IUNL PGUTI

The textbook includes sections that describe in detail the state of the art and methods of adaptive scheduling, a multi-agent approach to solving real-time dynamic resource scheduling problems, the architecture and implementation of a multi-agent transport resource management system. The theoretical material is illustrated by a large number of examples of dynamic planning. The manual contains control questions and exercises in all sections.

In order to enter a new entry, you must click on the "Create" button located at the top<...>tractors The "Location of tractors" option is designed to display all tractors on the specified date (Figure<...>Figure 73 - Location of tractors 3.4.4.3 View route<...>The planned location of resources at the time of the preferred start of the execution of the order AT000018 is given<...>Figure 113 - Setting a preferred resource Location of resources at the time of the start of request planning

Preview: Real-time Multi-Agent Mobile Resource Management.pdf (0.4 Mb)

No. 8 [Transport construction, 2010]

Information about organizations and enterprises of transport construction, their capabilities, complexity and quality of work performed and services provided.

For a rotor with radial blades (β = 0), inequalities (16), (17) take the form: N � 0 V0<...>When using rotors with a similar arrangement of blades in real-life technological machines<...>Rotors with a similar arrangement of blades are advisable to use in cases where intensive<...>With a radial arrangement of the rotor blades, the equation (13) of the relative motion of particles along them remains<...>The theoretical studies carried out allow us to draw the following conclusions: the location of the blades

Preview: Transport construction №8 2010.pdf (0.2 Mb)

Veterinary and sanitary examination lab. workshop

The textbook discusses modern organoleptic and laboratory methods of veterinary and sanitary examination of meat and meat products, as well as products of plant origin. The laboratory workshop contains requirements for the quality and safety of products based on current regulatory documents. The manual contains brief theoretical information on the veterinary and sanitary examination of products, which contributes to a better mastering of the discipline.

the esophagus in a single joint is suspended by the trachea on a hook or placed on a table in such a way that their location<...>Cut all bronchial, as well as deep cervical lymph nodes located along the trachea.<...>The topography of the location of the main internal organs and large lymph nodes is close to that of<...>Trichinella larvae are visible as roundworms up to 1 mm long with pointed edges, twisted into a spiral, located<...>using color standards sealed in test tubes and a comparator with six sockets (Figure 1.17) located

Preview: Veterinary and sanitary expertise.pdf (0.6 Mb)

I live in Siberia, for a long time I have been fond of hunting and fishing. Our places are amazing. There are many rivers, lakes, rich in fish and game. Most of all I like to hunt waterfowl. But sometimes it is impossible to take it: impenetrable swamps, floodplains, quicksands, impassable reeds.

<...>with outer corner 12 - hinged blade; 13 - outer duralumin corner.<...> <...> <...>And with the lateral arrangement of the blades, you can walk both in clean and overgrown reservoirs.

INVESTIGATION AND SUBSTANTIATION OF OPTIMAL PARAMETERS AND MODE OF OPERATION OF ROTARY Ditch Cleaning Machines ABSTRACT DIS. ... CANDIDATE OF TECHNICAL SCIENCES

This work is devoted to the choice of the most rational type of working body, the study and justification of its main parameters and mode of operation in relation to the cleaning of small and. medium channels

With a radial arrangement of the blades,<...>^n ;" " . в ~ 2648700h » (23)<...>blades.<...>blades.<...>With this arrangement, the jet of soil ejected by the working body is more compact, and near the working

Preview: RESEARCH AND SUBSTANTIATION OF OPTIMUM PARAMETERS AND OPERATING MODE OF ROTARY Ditch Cleaning Machines.pdf (0.0 Mb)

RESULTS OF THEORETICAL AND EXPERIMENTAL INVESTIGATIONS OF MULTI-BLADE ROTARY TYPE WORKING BODIES FOR SOLID MANURE DISTRIBUTION [Electronic resource] / A.P. Dyachkov [and others] // Bulletin of the Voronezh State Agrarian University. - 2014 .- No. 1-2 .- P. 80-86 .- Access mode: https://site/efd/386825

The results of theoretical and experimental studies of the process of spreading solid manure by a spreader from rolls with multi-bladed rotor-type working bodies are presented. The rational values of the design and operating parameters of the proposed design are determined, which ensure the high-quality application of solid organic fertilizers that meets the agrotechnical requirements.

of the last row of rotors, equal to R = 0.4 m, providing the theoretical flight range, with a radial arrangement<...>Theoretical dependences of the “limiting” loading zone on the angle of inclination of the blades for different lengths of the blades<...>The results of theoretical studies to justify the number of rows of blades and the radius of the blades of each<...>All blades on the rotor were mounted radially. The width of the blades was bl = 0.13 m.<...>movement speed (Vр = 1.55…1.63 m/s), the number of rows of blades (from 2 to 4 rows) and the number of blades

Calculation of a centrifugal compressor method. instructions for course design in the discipline "Thermal engines and superchargers"

Methodological instructions are presented for students studying in the direction of "Heat power engineering" full-time and part-time forms of education.

impeller in two projections showing the location of the blades and the pump housing.<...>According to the shape and relative position of the streamlines in the plan, one can judge the smoothness of the shape of the blade (Figure<...>The construction of a spiral outlet located behind a vaned diffuser is carried out in the same way.<...>ratios bsp/bd = 1.0 ÷ 1.5, the opening angle of the sections of the spiral  = 50 ÷ 60 °, while for a spiral located<...>Vane diffuser

Preview: Calculation of a centrifugal compressor.pdf (0.4 Mb)

M.: PROMEDIA

The number and arrangement of vanes within the raw material inlet. 6.<...>and the number of blades).<...>Rice. 9–11 show the location of the CFD for the three heights along with the steam trajectory lines colored with<...>In the case of the radial opposite arrangement of fittings, we reached the maximum peak speed of 143.5<...>minimum entrainment within the criteria for optimal steam distribution and has a piece of space for arranging

INVESTIGATION AND INVESTIGATION OF A ROTARY WORKING BODY FOR ACTIVE LOOSENING AND SOIL SEPARATION IN POTATO HARVESTER ABSTRACT DIS. ... CANDIDATE OF TECHNICAL SCIENCES

BELARUSIAN SCIENTIFIC RESEARCH INSTITUTE OF AGRICULTURE

Therefore, the improvement of existing and the search for new methods of separation of soil and working bodies for these purposes is an important task.

located behind the rotor.<...>- the angle of friction of the tubers on the blade.<...>There are three ways to position the blade on the rotor drum: along a radius of 7 - 0 "» with a forward inclination 7<...>with the blade tilted back, which provides maximum driving force along the blade.<...>D - - 1000 mm; b) rotor drum diameter d = 300 mm; c) number of blades z = 8; d) pitch of the helical blade

Preview: INVESTIGATION AND INVESTIGATION OF A ROTARY WORKING BODY FOR ACTIVE LOOSENING AND SEPARATION OF SOIL IN POTATO HARVESTERS.pdf (0.0 Mb)

The article presents the results of experimental studies on the study of the process of grinding clinker in a press-roll grinder and in a ball mill equipped with energy exchange devices. The designs of energy-exchange devices are determined, which make it possible to create an effective force effect of grinding bodies on the crushed material.

In this regard, studies were carried out to study the influence of the relative position of the power plant, operating modes<...>The working surfaces of the elliptical segment and the double-acting blades are parallel to each other,<...>grinder and ball mill equipped with energy exchange devices: 1 - PVI; 2 - drum; 3 - blade<...>Romanovich From the graphic dependence Q, N, q = f(ξ, ϕ 2) (Fig. 4) it is established that the relative position<...>double-acting blades and elliptical segment in the mill drum has a significant impact on

General ichthyology workshop

The workshop contains laboratory work on the study of external features, body shape, fins, scales, muscles of fish; their measurement and anatomical dissection. At the same time, special attention is paid to provisions that contribute to a deep study of external features that are of systematic importance and reflect the exceptional adaptability of various fish species to living conditions.

The length of the upper and lower lobes of the caudal fin (C) is the length of the largest rays of the upper and lower lobes<...>Drawings: “Different mouth shapes”, “Fish mouth sizes”, “Eyes position”, “Nostril position in fish”<...>This arrangement is called jugular, and it is typical for large-headed fish with a compact arrangement.<...>) the upper lobe is shorter (flying fish, sabrefish), with isobathic (isocercal) both lobes have the same<...>Figure 23 - Scheme of the location of the blades of the tail fin relative to the zone of vortices and the friction layer at

Preview: General Ichthyology.pdf (0.2 Mb)

the technical characteristics and examples of the use of some types of connections of wooden structures that have been developed over the past century are given. An analysis of the advantages and disadvantages of connectors such as ring, tee and disk dowels, claw and glued washers, glued wavy toothed dowels is given. The assortments and values \u200b\u200bof the bearing capacity of some connectors are given

Increased requirements for manufacturing accuracy, quality and moisture content of wood. ring key with blades<...>blades.<...>These blades are pieces of strip steel with a length equal to approximately three times the diameter of the ring.<...>The key consists of a metal strip with teeth stamped in it, located asymmetrically.<...>The key is equipped with teeth and spikes located respectively on the troughs and ridges from the side of Copyright

Wind power installations and prospects for their use in the Arctic zone of the Russian Federation: textbook. allowance

The relevance of the development of wind energy in Russia, including in its Arctic zone, is substantiated. The data on wind power plants (WPPs) and wind energy are summarized, the classification of wind power plants and information on the airfoils used are given. A methodology for assessing the wind energy potential and an example of its practical implementation for the Solovetsky Archipelago are presented. The issues of designing wind farms with the help of Windsim, as well as the impact of wind turbines on the environment, are considered. The state and prospects for the development of wind energy in the Arkhangelsk region and the Nenets Autonomous Okrug are presented. The initial data for the performance of individual tasks are given.

historically established energy supply systems, improving the energy security of areas and consumers located<...>Torque is also generated by the lifting force of two vertically arranged blades with aerodynamic<...>the blade rotates in a turbulent flow disturbed by the previous blades.<...>the most basic aesthetic requests; – carrying out computer simulations with various options for location<...>However, when the wind turbine is located at a distance of 300 m from the place of permanent residence of people, the level

Preview: Wind power installations and prospects for their use in the Arctic zone of the Russian Federation. manual.pdf (1.3 Mb)

STUDY OF THE MIXING PROCESS IN A TWO-SHAFT HORIZONTAL FEED MIXER WHEN PREPARING A MIXTURE OF WET FOOD ABSTRACT DIS. ... CANDIDATE OF TECHNICAL SCIENCES

AZERBAIJAN AGRICULTURAL INSTITUTE OF NAMES

Tasks: a) to investigate the physical and mechanical properties of wet crust mixtures; b) identify the main patterns of distribution of various components in wet feed mixtures; c) identify the factors of the mixing process that affect the consumption of anergy; d) to establish the optimal parameters of a two-room continuous paddle feed mixer, providing effective mixing.

Mm; R is the outer radius of the blade , wі ; Z is the distance from the lower edge of the blade to the axis of the blade shaft,<...>when the blades are located at an angle ot » 10, 20, 35, 45 "and 60° relative to the shaft axis" 3) Depending on the type<...>and the shape of the blades, the power consumption was studied on 3 constructive shapes and dimensions of the blades. "".*) From „<...>on the blade width and, according to the obtained experimental data, the optimal blade width is determined<...>blade width.

Preview: STUDY OF THE MIXING PROCESS IN A TWO-SHAFT HORIZONTAL FEED MIXER WHEN PREPARING A MIX OF WET FOOD.pdf (0.0 Mb)

THE ROLE OF LEXICAL AND GRAMMAR TRANSFORMATIONS IN THE TRANSLATION OF A TECHNICAL TEXT

FGBOU VPO "IGLU"

The purpose of the work is to determine what difficulties a translator faces in working with technical texts in Spanish, and to identify methods for solving translation problems.

<...>deflection of the blade during rotation of the propeller.<...>Figure 2.6 shows various ways of arranging the rotor blades.<...>rotation of the blade in the main rotor hub.<...>However, when the blade swings, the distance between the center of gravity of the blade and the center of gravity of the blade itself changes.

Preview: THE ROLE OF LEXICAL AND GRAMMAR TRANSFORMATIONS IN THE TRANSLATION OF A TECHNICAL TEXT.pdf (1.1 Mb)

No. 10 [Invention, 2010]

Theory and practice of creating inventions and registration of rights to inventions, information about the most important inventions, regulations, court decisions.

Located along a helical line (Fig. 3).<...>Due to the location of the blades along a helical line, the proton rotates during its interaction<...>The electron, due to its figured shape in the form of a twisted blade, occupies on the proton at the ends of its blades<...>X. No. 10. 2010 38 to the crest of one of its blades.<...>X. No. 10. 2010 39 between their blades.

Preview: Invention №10 2010.pdf (0.2 Mb)

No. 5 [Humanities and social sciences, 2016]

The scientific journal "Humanitarian and Social Sciences" is an online publication that publishes articles, messages, reviews and other materials of an educational, scientific, humanitarian, socio-economic and cultural nature and provides an opportunity for teachers, doctoral students, graduate students, practitioners to present the results of their scientific research for the widest possible audience.

The location of the members of the sentence - determinants, subject, predicate - within the topic is relatively<...>Nauki 2016. No. 5 105 Copyright JSC "Central Design Bureau "BIBCOM" & LLC "Agency Book-Service" In the above example, the location<...>Location in the theme of the component of the verbal predicate and other members of the sentence (subject<...>winged or with a wing: the hair is pulled together with a sderich at the back of the head, the magpie is attached behind with wings, lobes<...>"friendly zone" - "disposition of friendly troops").

Preview: Humanities and Social Sciences #5 2016.pdf (0.4 Mb)

№3 [Helicopter industry, 2011]

The HELICOPTER INDUSTRY magazine is a competent analysis of the Russian helicopter industry. This is a publication that meets the interests of the heads of Russian aviation enterprises. This is a respectable magazine aimed at all representatives of business aviation. The magazine is published for organizations providing services in the helicopter and aircraft industries, in business aviation, for representative offices of foreign companies, aviation holdings throughout Russia and owners of private helicopters. The magazine is published by the ASSOCIATION OF THE HELICOPTER INDUSTRY (AVI), the first organization in Russia that combines all the main structures of the helicopter industry that exist today in Russia.

overlays, through them a helical column is mounted in the center of the blade.<...>The only place that was not allowed to be visited was the control and test station located<...>The fuel tanks on the machines are connected to a 7-ton fuel tank located behind a protective concrete<...>Russia has vast territories and large volumes of natural resources located in areas where it is difficult to<...>with uneven blade spacing make the EC135 the quietest helicopter in its class.

Preview: Helicopter Industry #3 2011.pdf (0.3 Mb)

Aboriginal, ancient varieties growing in various regions of grape cultivation are an important part of the world crop gene pool. Many native Don grape varieties (Vitis vinifera L.) are of significant value for cultivation and use in breeding work. Among the varieties of the Don, there are groups that are close in terms of the main characteristics, as well as more distant ones. The main features of the leaves of grape varieties are the most important ampelographic feature. DNA research is the most informative method for analyzing plant genotypes. Microsatellite markers are widely used for genotyping grape varieties and rootstocks, and are also successfully used in studying the origin of varieties and analyzing their pedigrees. We assessed the relationship of a number of Don varieties based on the results of microsatellite genotyping. The purpose of this work was to study the genetic similarity of native Don varieties based on DNA analysis and compare the results obtained with the analysis of the main features of the formed leaf, as well as the conclusions of other authors. The studies were carried out on 16 varieties growing in the collection of the All-Russian Research Institute of Viticulture and Winemaking named after V.I. ME AND. Potapenko (Novocherkassk) and in the Russian ampelographic collection (Anapa). All studied varieties were described according to the main ampelographic features. We used the polymerase chain reaction with the separation of its products by electrophoresis. DNA was isolated from young leaves of the apical part of the shoots of 4–5 typical bushes of the variety. We used six SSR markers recommended as the main ones for V. vinifera fingerprinting. The control varieties were Chardonnay and Cabernet Sauvignon, the allelic composition of which is known for the studied SSR loci. The matrix of genetic distances was built using similarity coefficients (indices) according to M. Nei and W. Li. Cluster analysis based on SSR genotyping data was performed by pairwise unweighted clustering with arithmetic averaging (UPGMA). Conducted a graphical construction of dendrograms. The data on leaf morphological traits and the results of SSR genotyping were analyzed by the principal coordinates method (PCA). Using an automatic genetic analyzer ABI Prism 3130 (Applied Biosystems, USA), DNA profiles of local Don grape varieties were obtained for microsatellite loci VVMD5, VVMD7, VVMD27, VVS2, VrZAG62, and VrZAG79. In the genotypes of the studied Don varieties, six (at the VVS2, VVMD5, VVMD7, VrZAG62 loci) and seven (at the VVMD27, VrZAG79 loci) alleles per locus were identified. Cluster analysis made it possible to divide the varieties into two main branches: one included Siberian, Pukhlyakovsky white, Sivolistny, Pukhlyakovsky black, Kosorotovsky and Kukanovsky (all of them belong to the group of natural seedlings of Pukhlyakovsky white), the other included Bezymyanny Donskoy, Plechistik bisexual, Stary Goryun, Tsimlyansky white, Tsimlyansky black, Tsimladar, Plechistik, Sypun black, Makhrovatchik and Bessergenevsky ¹ 7. It is interesting that three subgroups were distinguished in the second branch. One included the varieties Bezymyanny Donskoy, Plechistik bisexual, Tsimlyansky white, Tsimlyansky black, Tsimladar, Plechistik, Sypun black (a group of Tsimlyansky varieties), the other included Bessergenevsky ¹ 7 (presumably a seedling of Pukhlyakovsky white) and Stary Goryun (a group of Tsimlyansky varieties); the cultivar Makhrovatchik stood out separately (it is considered a seedling of the cultivar Kokur white). In the space of principal coordinates, we did not find the distribution of varieties according to the main features of the leaves in accordance with their supposed origin. According to the results of the SSR analysis, most varieties were distributed in accordance with previously made conclusions about their origin. Thus, the assessment of collections, ancient varieties, breeding material and introduced accessions according to a complex of ampelographic features and SSR markers can be considered the most informative. Key words: native gene pool, SSR markers, ampelographic features of leaves, Vitis vinifera L., Don grape varieties, genetic similarity.

apical tooth to its width, 078-2 - the ratio of the length of the lateral tooth to its width, 068 - the number of lobes<...>, 067 - shape of the plate, 065 - size of the plate, 082 - location of the blades of the upper side notches,<...>079 - location of the lobes of the petiole notch, 084 - cobwebby pubescence between the main veins on

No. 8 [Model designer, 2015]

Popular monthly scientific and technical magazine. Published since August 1962 in Moscow. Well-known aircraft designers A. Tupolev, S. Ilyushin, cosmonaut Yu. Gagarin gave good parting words to the new edition. Since then, for over forty years now, the magazine has been covering issues of scientific and technical creativity, amateur design, and tells about the history of domestic and foreign technology. Among its authors, along with famous inventors and designers, champions of technical sports, there is a large army of versatile craftsmen, lovers of technology and its history. "Modeler-Designer" is the only magazine in the country, in each issue of which drawings, diagrams and descriptions of a variety of home-made structures are printed. The editors see one of the main tasks in helping every reader, no matter what age he is, to become a jack of all trades, not only a connoisseur of technology, but also a versatile craftsman, able to make everything necessary for work and leisure with his own hands. THE TRANSFER OF SUBSCRIPTION NUMBERS IS CARRIED OUT WITH A DELAY OF 12 MONTHS!!!

Rods (11) with small “fins”-blades (12) are fixed on them.<...>Blade pattern and its fastening Fig. 5.<...>The first skis I made were with bottom blades.<...>And with the lateral arrangement of the blades, you can walk both in clean and overgrown reservoirs.<...>The location of the fibers is along the largest size.

Preview: Model Designer No. 8 2015.pdf (0.1 Mb)

No. 6 [Aviacollection, 2014]

Supplement to the magazine "Modelist-constructor", published since July 2003. Specialized magazine for lovers of aviation history and aircraft modellers. Each issue is a mini-monograph about domestic or foreign design of aircraft. Each issue contains information about the history of the creation of an aircraft or helicopter, its serial production, modifications, operation, combat use and painting. A brief technical description and drawings of the machine are given. As well as a large number of photographs, including photographs of components and assemblies. THE TRANSFER OF SUBSCRIPTION NUMBERS IS CARRIED OUT WITH A DELAY OF 12 MONTHS!!!

The pilot sat in a chair located in the diametrical plane, on the sides and slightly behind were places<...>The mutual arrangement of the blades and the absence of a general unbalance of the propeller were guaranteed by three cables<...>Trimmers are glued to the stringer for finishing the blade.<...>The tip of the blade is bound with a thin strip of stainless steel.<...>In front of the cockpit there are three adjacent seats: for pilots (two extreme) and a passenger

Preview: Air Collection No. 6 2014.pdf (0.4 Mb)

Fundamentals of construction and design of vibratory mixers [monograph]

Based on known designs and research results, the monograph proposes design principles for vibratory mixers that ensure the preparation of promising building materials with the necessary physical and chemical characteristics.

;  the angle of inclination of the blade to the horizon.<...>Bladed concrete mixers : N k FR   , where F is the frontal area of the blade ; R blade installation radius<...>;  angular speed of the blade; k coefficient of resistance of the mixture to the rotation of the blades.<...>and mass of batch; z number of blades ; R r, respectively, the radii of the end and beginning of the blade;  number of revolutions<...>, L is the width of the blade , h is the gap between the edge of the blade and the wall of the mixing chamber, V is the volume of the mixture.

Preview: osnovy-konstruirovanija.pdf (0.1 Mb)

No. 1 [Scientific and technical bulletin of the Bryansk State University, 2018]

The journal specializes in the publication of scientific articles containing new scientific results in the field of theoretical and applied research and corresponding to the following branches of science from the Nomenclature of Specialties of Scientific Workers: 02 - chemical sciences; 05 - technical sciences; 25 - earth sciences.

blades 32 using clamps 33 and locking screws 34.<...>For sealing gaps between the mating surfaces of the blades and the inner surface of the shell<...>in each blade, a groove 37 is made to install the sealing element 38.<...>with the number of installed partitions (blades).<...>The use of various schemes for the location of the passages of the warehouse of packaged cargo / D.I.

Preview: Scientific and Technical Bulletin of the Bryansk State University No. 1 2018.pdf (1.9 Mb)

Cooling systems for piston internal combustion engines textbook. allowance

SSAU publishing house

Cooling systems for reciprocating internal combustion engines. Programs used: Adobe Acrobat. Proceedings of SSAU employees (electronic version)

The blades can be swivel.<...>tubes at an angle to the airflow, 2 staggered tubes, 3 rows of tubes<...>The operation of the fan is affected by its location in the casing in depth.<...>But the location of its blades should be more accurate, because due to the possible mismatch of the vectors<...>with blades bent back.

Preview: Cooling systems for reciprocating internal combustion engines.pdf (0.8 Mb)

The article "Blade bit with enhanced peripheral cutting tools" is devoted to the substantiation of a number of the most important parameters of the blade bit of the cutting-shearing principle of operation - increasing the performance of the peripheral and central cutting structure of the bit

In this case, a prerequisite is the location of these elements at different levels relative to<...>The practice of working out bladed bits shows that the nature of the wear of the cutting structure located on<...>The volumetric work of destruction of peripheral incisors is much greater than the volumetric work of incisors located on<...>The location of the paired incisors on the periphery of the blade To ensure the possibility of placement on the peripheral<...>blades .

Axial and centrifugal pumps of thermal power plants studies. allowance

M.: FLINTA

The manual discusses the principles of operation, energy characteristics and designs of axial and centrifugal pumps, as well as their elements. The classification of pumps and the features of their operation as part of pumping units and networks are presented. The characteristic damages of pump elements that occur during operation are considered. Methods for determining the hydraulic and geometrical parameters of the designed pumps and features of the selection of serial pumps for the required conditions are given.

<...> <...>and vertical shaft.<...>impeller; OP - with rotary blades of the impeller; B - with a vertical shaft<...>The location of the paws here is lower.

Preview: Axial and centrifugal pumps TPP.pdf (0.7 Mb)

A constructive and technological method is proposed to increase the wear resistance and durability of the mixer blades, which consists in surfacing wear-resistant beads arranged in a chevron pattern to form a protective layer of the technological mass on the friction surface, which provides a "shadow effect" - shielding the working surface of the blades from the impact of abrasive particles.

mixer, which consists in surfacing wear-resistant beads arranged in a chevron pattern to form<...>The layout of the deposited beads provides for the implementation of the so-called shadow effect [<...>; 4 - blade holder; 5 - upper mixing blade; 6 – bottom mixing blade Yu.I.<...>the location of the beads, the width and height of the beads, as well as the corresponding deposition pitch.<...>rollers arranged in a chevron pattern can increase the durability of the blades by 1.3–1.5 times compared to

Wind turbines study. allowance

M.: Publishing house of MSTU im. N.E. Bauman

The principles of operation and arrangement of wind turbines of various types, as well as the features of their regulation (control) are considered.

As a result, when large wind turbines are located at a distance of no closer than 250 m from residential buildings, the noise level does not<...>on the direction of the wind (top view): a - with the help of the tail unit; b - with the help of windroses; c - location<...>They are small wind wheels located perpendicular to the plane of rotation of the main<...>Orientation using the location of the wind turbine behind the vertical axis of rotation is based on the fact that<...>The turning mechanism can be controlled by a centrifugal regulator located on the main vertical

Preview: Wind turbines.pdf (0.2 Mb)

Theoretical and experimental studies of mixing dry ingredients and microadditives in a paddle mixer. Theory, design, calculation monograph

RIO PGSKHA

The monograph summarizes the results of theoretical and experimental studies of the process of mixing dry components in a mixer of microadditives. The indicators characterizing the quality of the prepared mixture and the energy intensity of the mixing process are given. A new design scheme of the mixer of microadditives has been developed, and the optimal design parameters of the mixer have been substantiated in terms of the minimum energy intensity of mixing.

Through the receiving neck located under the unloading chute 9, the component enters the loading screw<...>Components are loaded with a vertical arrangement of the mixer body through one of the outer holes<...>The resulting mixture is discharged through the lower opening of the housing with the vertical arrangement of the micromixer<...>The mixing devices themselves are made in the form of horizontally arranged shafts with blades.<...>showed the presence of two zones of the supposed location of the minimum energy intensity.

Preview: THEORETICAL AND EXPERIMENTAL STUDIES OF MIXING DRY COMPONENTS AND MICROADDITIONS IN A PANE MIXER.pdf (0.6 Mb)

Road construction machines and complexes

The fundamentals of theory and design, the features of the calculation and design of machines for the construction and maintenance of roads, airfields and municipal services, the restoration and repair of road surfaces are outlined.

Such a requirement is more or less satisfied in the "commodity arrangement of the blades.<...>In twin-shaft trough mixers, counter-rotating shafts with blades located<...>The height of the blades for different points of the blade along its length is different.<...>blades, m).<...>blades, m; y is the angle between the plane of the blade and the axis of the shaft; RH, Re outer and inner blade radii

Preview: Road-building machines and complexes.pdf (0.1 Mb)

The failures and energy characteristics of Kaplan turbines, which have long expired their standard service life, are analyzed. The expediency of replacing morally obsolete and physically worn rotary-vane impellers with new radial-axial wheels is substantiated.

The underground Ust-Khantayskaya HPP with the location of the machine room at a depth of 47 m belongs to such a case.<...>Scheme of the location of damage to the blades of the axial turbine Fig. 2.<...>zNA is the number of guide vanes, frev is the turbine speed), which is caused by the proximity<...>Actual “blade-chamber” clearance of the turbines of the Ust-Khantayskaya HPP Unit Number of the turbine blade Medium<...>Selection of parameters for new equipment In the climatic conditions of the location of the underground Ust-Khantai

Key to trees and shrubs of European Russia, the Crimea and the Caucasus by leaves and flowers with numerous rice. in the text

Berezovsky V. A., Ilyin A. A., Karbasnikov N. P. Orlov A. V.

Key to trees and shrubs of European Russia, the Crimea and the Caucasus by leaves and flowers

blade .<...>Tree with ringed branches.<...>H * C p R and in ™ ° transversely-sho-arranged, * G m e l U 1 r?<...>Buds and leaves bi-row-spiral arranged.<...>Nights and leaves oppositely arranged.

Preview: Key to trees and shrubs of European Russia, Crimea and the Caucasus by leaves and flowers.pdf (0.1 Mb)

Processing equipment workshop

RIC SGSKhA

The workshop considered machine-hardware diagrams of lines and basic equipment for the production of flour, cereals, animal feed, bakery products and vegetable oils, as well as technological equipment for processing livestock products.

Mutual arrangement of riffles.<...>In this case, the back-to-back arrangement of the corrugations is used.<...>bladeperforming a curvilinear plane motion; g - with a kneading blade, making a curvilinear<...>The blade makes planetary motion.<...>, paired with Z-shaped cylindrical blades (TM-63, RZ-KhTI-3), with a kneading blade in the form of a polygonal

Preview: Equipment for processing industries.pdf (2.2 Mb)

Calculation of helicopter parameters at the stage of preliminary design studies. allowance

The training manual describes methods for calculating the main parameters of a helicopter at the stage of a preliminary design: calculation of aerodynamic drag, takeoff weight, mass of units, power of the propulsion system, layout and alignment issues.

According to the installation angle φ07 of the blade section located at the estimated radius r07, the total pitch is determined<...>Geometric twist of the blade, which determines the angular position of a number of sections of the blade, located along<...>For sections located closer to the end of the blade, it is recommended to use high-speed profiles of the TsAGI type<...>In this case, the sections of the blade located closer to the axis of rotation and having low circumferential speeds work<...>The twist of the blade is represented as a series of angles φi of installation of section profiles located at different

Preview: Calculation of helicopter parameters at the stage of preliminary design.pdf (0.2 Mb)

The article "Blade bit operating in rock lateral shear mode" is devoted to the substantiation of a number of the most important parameters of a shear-cutting blade bit

operating experience of paddle bits determined the following basic requirements for their design: 1) location<...>In this case, an additional exposure plane is formed for the adjacent incisor.<...>the working elements of the blade could dump the destroyed rock.<...>But with this variant of the blade, the peripheral cutter must be ahead of the adjacent cutter by some<...>Such a layout of the peripheral cutter can only be used when drilling soft rocks,

Mechanical equipment and technological complexes studies. allowance

The basic theoretical information, the basics of calculation and design of machines and equipment are presented; a description of the designs of machines and equipment, the principle of their operation; the choice and calculation of technological lines and equipment complexes is proposed.

The block usually has seven cylinders arranged in a circle.<...>Blade 7 is designed to clean the walls of the body, and blade 4 - to clean the shell of the inner glass<...>Blade 21 is attached to the traverse, raking the mixture under the blades, and blades 24 and 23, cleaning the walls<...>; α is the angle between the plane of the blade and the axis of the shaft; δ is the number of blades within one propeller pitch.<...>Describe the layout of the mixers in the mixing compartments. 10.on the sides of the umbrella, have a rounded contour.

The textbook is intended for students in the field of preparation "Technology of bakery, pasta and confectionery production" of all forms of training in the study of the discipline "Technological equipment of industry enterprises", as well as in the course of course and diploma design.

parallel in a horizontal plane.<...>Inside the chamber, four blades are fixed on a horizontal shaft, located one relative to the other.<...>The required processing time at the corresponding speed is set using a relay located<...>blades 10.<...>2 located at the bottom of the trough.

Preview: Dough mixers and dough preparation units.pdf (0.5 Mb)

Pumps, fans, compressors. Calculation and selection of superchargers method. instructions for the course work on the discipline "Pumps, fans, compressors"

FSBEI HPE "Saratov State Agrarian University named after N. I. Vavilov"

The guidelines contain a number of theoretical materials on the topic "Pumps, fans, compressors". Here the main issues of calculation and selection of compressors of the required pressure and power are considered. A detailed analysis of the calculation of pumping systems is given, in particular, the calculation of a centrifugal pump, its impeller, which will allow students to independently select and calculate the impeller and present it in graphical form. The guidelines offer options for completing the course work.

: width of the channel in the meridian section 1b , the location of the leading edge of the blade and the radius of its midpoint<...>r1, as well as the entry angle of the blade β1.<...>, which is most often chosen equal to the speed ύ0, 11 1 1 2 mvr Q b     (13)<...>channel mvr Q b    2 (27)<...>Blade profiling.

Preview: Pumps, fans, compressors. Calculation and selection of superchargers. Guidelines for the implementation of the course work on the discipline "Pumps, fans, compressors".pdf (0.2 Mb)

A method has been developed for choosing a rational angle of inclination of the screw blade of a vertical screw conveyor, which makes it possible to take into account the physical and mechanical properties and geometric characteristics of the cross section of the flow of the transported material, as well as the processes occurring on the contact surfaces of the material with the working bodies of the conveyor, taking into account the imposed restrictions and the optimization criterion

. No. 5 55<...>screw blade has been little studied due to many factors affecting this value.<...>The input parameters are the blade radius R, the helix angle α.<...>formula vit 0 2/Q V k   , (2) where 0 is the angular velocity of the screw shaft, s –1; Vvit is the volume of material, located If necessary, it is possible to remove the force from the control stick and pedals by pressing a button. Currently, the reconstruction of the hydro turbines of the Rybinsk HPP, which have worked for more than 60 years, is underway. The purpose of the reconstruction: increase in power, efficiency and environmental friendliness. The refurbishment includes mechanical and hydraulic designs, strength justification, model testing and delivery. The driving wheel - environmentally friendly, without oil in the case. The article by specialists of the Hydroturbomash design bureau of Power Machines OJSC reflects the stages of reconstruction, the parameters of the hydroturbine before and after reconstruction

<...>with their bearing surfaces rotate in bushings and thrust rings located in the outer and inner<...>repair - at least 20 years. to prevent the entry of solid particles and water from the flow path into the location area<...>made of cavitation-resistant stainless steel, blade turning mechanism, servomotor located<...>with their bearing surfaces rotate in bushings and thrust rings located in the outer and inner

Mechanization of the technological process of milk separation

RIO PGSKHA

The basic information about the problem associated with the mechanization of milk separation is given. The methods, equipment and instrumentation of experimental studies in laboratory and production conditions of a separator-cream separator with a paddle plate holder are described. A theoretical and experimental substantiation of the design, kinematic and technological parameters of a separator-cream separator with a paddle plate holder has been carried out.

Table 1.2 presents the main fatty acids of milk fat in order of their location from the periphery<...>It consists of a frame 17 (Figure 1.8) with an oil level indicator 2 located on it, a drain plug<...>end of the blade, respectively, internal and external, m; 3R is the radius of location of the axis of the outlet hole<...>blade profile arc angle –(2.39); blade profile length - (2.40).<...>; blade profile curvature radius ; the central angle of the arc of the radius of curvature of the blade ; blade length.

Preview: Mechanization of the technological process of milk separation.pdf (0.8 Mb)

Until recently, the destruction of turbine cover fasteners was considered only on high-pressure radial-axial turbines (Sayano-Shushenskaya, Nurek HPP). Further study of the problem has established that the destruction of fasteners is also found on Kaplan turbines. So, during the overhaul in 2011 of the unit of the Uch-Kurgan HPP (nominal turbine power Nt = 45 MW with a design head Hp = 25.8 m), 26 destroyed studs out of 72 were found. occurred on March 10, 1992 at the Grand Rapids HPP (Canada). Three other units were also flooded. The degree of destruction at the station was very significant. More than $2 million was spent on clearing debris in the turbine hall alone. Let's take a closer look at this accident.

<...>pin tightness). when the fasteners are loosened, the vibrations of the turbine cover must be greater than the vibration of the adjacent<...>Location of sensors for measuring vibration velocities (a) and experimental pin (b) 3.<...>Layout of sensors for measuring vibration velocities and a sketch of an experimental stud with an installation location<...>Layout of sensors for measuring vibration velocities and a sketch of an experimental stud with an installation location

Conodonts from the Carboniferous and Lower Permian deposits of the Zaladu section, which is located in the eastern part of Iran, near the village of Gushkamar, were studied. About 50 conodont elements were identified, on the basis of which, for the first time for Iran, conodont assemblages of the Lower Bashkirian, the upper part of the Moscovian, the lower Kasimovian, the upper part of the Gzhelian, and the base of the Asselian were established. In a single section, the position of the Carboniferous–Permian boundary is outlined by the appearance of S. nodulinearis and S. isolatus. 12 species of conodonts belonging to 4 genera were identified, 9 forms were identified in the open nomenclature, most of them are described and depicted.

Additional blade, located on the inside, protrudes beyond the contour of the platform, carries the sculpture<...> <...>There are no additional blades.<...>located outside the platform parallel to the axial ridge.<...>located parallel to the axial ridge.

Informatization of technological equipment of ship engineering

Northern (Arctic) Federal University named after M.V. Lomonosov

The most urgent problems of informatization of modern machine-building production are considered and optimal methods and ways of their solution in the current economic conditions are proposed. The proposed technical solutions for the modernization of various technological equipment make it possible to give obsolete equipment new technological capabilities, increase the accuracy class of technological equipment, expand the functionality of machine tools and the range of processed products, reduce the labor intensity of processing, increase the efficiency and accuracy of control, and improve the quality of technological operations.

The movement of the caliper is controlled by signal lamps located on the control panel<...>Disabling copying is carried out by pressing the Kn5 button located on the copy remote control.<...>The layout of the functional blocks of the central control system of the machine is shown in fig. 4.9.<...>The layout of the functional blocks of the TsSUI: 1 - vertical column of the machine; 2 - spindle head<...>First of all, the number and relative position of points are determined (aboutCopyright JSC "Central Design Bureau "BIBCOM"

Preview: Informatization of technological equipment of ship engineering.pdf (1.1 Mb)

, wind turbines, mills, hydraulic and pneumatic drives).

In blowers, vanes or vanes move the flow. In drive - the flow of liquid or gas sets the blades or blades in motion.

Operating principle

Depending on the magnitude of the pressure drop on the shaft, there may be several pressure stages.

Main types of blades

Blade machines, as the most important element, contain discs mounted on a shaft, equipped with profiled blades. Disks, depending on the type and purpose of the machine, can rotate at completely different speeds, ranging from units of revolutions per minute for wind turbines and mills, to tens and hundreds of thousands of revolutions per minute for gas turbine engines and turbochargers.

The blades of modern bladed machines, depending on the purpose, the task performed by this device and the environment in which they operate, have a very different design. The evolution of these designs can be traced when comparing the blades of medieval mills - water and windmills, with the blades of a wind turbine and a hydroelectric power plant.

The design of the blades is influenced by parameters such as the density and viscosity of the medium in which they operate. A liquid is much denser than a gas, more viscous and practically incompressible. Therefore, the shape and dimensions of the blades of hydraulic and pneumatic machines are very different. Due to the difference in volumes at the same pressure, the surface area of the blades of pneumatic machines can be several times larger than the blades of hydraulic ones.

There are working, straightening and rotary blades. In addition, compressors can have guide vanes, as well as inlet guide vanes, and turbines can have nozzle vanes and cooled vanes.

Blade design

Each blade has its own aerodynamic profile. It usually resembles an aircraft wing. The most significant difference between a blade and a wing is that the blades operate in a flow whose parameters vary greatly along its length.

Blade profile

According to the design of the profile part, the blades are divided into blades of constant and variable sections. Blades of constant section are used for steps in which the length of the blade is not more than one tenth of the average diameter of the step. In high-power turbines, these are, as a rule, the blades of the first high-pressure stages. The height of these blades is small and amounts to 20–100 mm.

Variable section blades have a variable profile at subsequent stages, and the cross-sectional area gradually decreases from the root section to the top. In the blades of the last steps, this ratio can reach 6–8. Blades of variable section always have an initial twist, that is, angles formed by a straight line connecting the edges of the section (chord) with the turbine axis, called the angles of the sections. These angles, for reasons of aerodynamics, are set differently in height, with a smooth increase from the root to the top.

For relatively short blades, the profile swirl angles (the difference between the installation angles of the peripheral and root sections) are 10–30, and for the blades of the last stages they can reach 65–70.

The relative position of the sections along the height of the blade during the formation of the profile and the position of this profile relative to the disk is the installation of the blade on the disk and must meet the requirements of aerodynamics, strength and manufacturability.

Blades are mostly made from preformed blanks. Methods for manufacturing blades by precision casting or precision stamping are also used. Modern trends in increasing the power of turbines require an increase in the length of the blades of the last stages. The creation of such blades depends on the level of scientific achievements in the field of flow aerodynamics, static and dynamic strength and the availability of materials with the necessary properties.

Modern titanium alloys make it possible to manufacture blades up to 1500 mm long. But in this case, the limitation is the strength of the rotor, the diameter of which has to be increased, but then it is necessary to reduce the length of the blade to maintain the ratio for reasons of aerodynamics, otherwise increasing the length of the blade is ineffective. Therefore, there is a limit to the length of the blade, beyond which it cannot work effectively.

Scallops of the labyrinth seal of the radial clearance
bandage shelf
Combs of mechanical labyrinth seal
Hole for supplying cooling air to the internal channels of the cooled blade

Tail part of the blade

The designs of tail connections and, accordingly, blade shanks are very diverse and are used based on the conditions for ensuring the necessary strength, taking into account the development of technologies for their manufacture at an enterprise manufacturing turbines. Types of shanks: T-shaped, mushroom-shaped, forked, fir-tree, etc.

No one type of tail connection has a particular advantage over the other - each has its own advantages and disadvantages. Different factories make different types of tail connections, and each of them uses its own manufacturing techniques.

The main types of blade shanks: 1. T-shank; 2. Mushroom shank; 3. Forked shank; 4. Christmas tree shank

Connections

Turbine rotor blades are connected into packs with links of various designs: bandages riveted to the blades or made in the form of shelves (solid milled bandage); wires soldered to the blades or freely inserted into the holes in the profile part of the blades, and pressed against them by centrifugal forces; with the help of special protrusions welded to each other after the blades are assembled on the disk.

Blade assembly elements: 1. Blade feather; 2. Shelf; 3. Shank; 4. Bandage tube

Steam turbine blades

The difference in the size and shape of the blades at different pressure stages of the same turbine

The purpose of turbine blades is to convert the potential energy of compressed steam into mechanical work. Depending on the operating conditions in the turbine, the length of its rotor blades can vary from several tens to one and a half thousand millimeters. On the rotor, the blades are arranged in steps, with a gradual increase in length, and a change in the shape of the surface. At each stage, the blades of the same length are located radially to the rotor axis. This is due to the dependence on parameters such as flow, volume and pressure.

At a uniform flow rate, the pressure at the turbine inlet is maximum, and the flow rate is minimal. When the working fluid passes through the turbine blades, mechanical work is performed, the pressure decreases, but the volume increases. Consequently, the surface area of the working blade increases and, accordingly, its size. For example, the blade length of the first stage of a steam turbine with a capacity of 300 MW is 97 mm, the last - 960 mm.

Compressor blades

The purpose of compressor blades is to change the initial parameters of the gas and convert the kinetic energy of the rotating rotor into the potential energy of the compressed gas. The shape, dimensions and methods of fixing compressor blades on the rotor do not differ much from turbine blades. In the compressor, at the same flow rate, the gas is compressed, its volume decreases, and the pressure increases, therefore, at the first stage of the compressor, the length of the blades is greater than at the last.

Blades of gas turbine engines

A gas turbine engine has both compressor and turbine blades. The principle of operation of such an engine is to compress the air necessary for combustion with the help of turbocharger blades, to direct this air into the combustion chamber and, when ignited with fuel, to mechanically work the combustion products on the turbine blades located on the same shaft as the compressor. This distinguishes the gas turbine engine from any other machine, where there are either compressor blowing blades, as in superchargers and blowers of all kinds, or turbine blades, as in steam turbine power plants or in hydroelectric power plants.

Blades (vanes) of hydraulic turbines

Disc with hydraulic turbine blades

Wind turbine blades

Compared to the blades of steam and gas turbines, the blades of hydraulic turbines operate in an environment with low speeds but high pressures. Here, the length of the blade is small relative to its width, and sometimes the width is greater than the length, depending on the density and specific volume of the liquid. Often the blades of hydraulic turbines are welded to the disk or can be manufactured entirely with it.

GOST R 52692-2006
(ISO 484-1:1981)

Group D44

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

Shipbuilding

SHIP PROPELLERS

Manufacturing tolerances

Part 1

Propellers with a diameter of more than 2.5 m

Shipbuilding. Ship screw propellers. manufacturing tolerances.
Part 1. Propellers of diameter greater than 2.5 m

OKS 47.020.20
OKP 64 4700

Introduction date 2007-07-01

Foreword

The goals and principles of standardization in the Russian Federation are established by the Federal Law of December 27, 2002 N 184-FZ "On Technical Regulation", and the rules for the application of national standards of the Russian Federation - GOST R 1.0-2004 "Standardization in the Russian Federation. Basic provisions"

About the standard

1 PREPARED by the Research Institute for Standardization and Certification "Lot" of the Federal State Unitary Enterprise "Central Research Institute named after academician A.N. Krylov" on the basis of an authentic translation of the international standard specified in paragraph 4

2 INTRODUCED by the Technical Committee for Standardization TC 5 "Shipbuilding"

3 APPROVED AND PUT INTO EFFECT by Order of the Federal Agency for Technical Regulation and Metrology dated December 27, 2006 N 354-st

4 This standard is a modification of the international standard ISO 484-1:1981 "Shipbuilding - Shipbuilding propellers - Manufacturing tolerances - Part 1: Propellers with a diameter of more than 2.5 m" (ISO 484-1:1981 "Shipbuilding - Ship screw propellers - Manufacturing tolerances - Part 1: Propellers of diameter greater than 2,5 m") by introducing technical deviations explained in the introduction to this standard

5 INTRODUCED FOR THE FIRST TIME

Information about changes to this standard is published in the annually published information index "National Standards", and the text of changes and amendments - in the monthly published information indexes "National Standards". In case of revision (replacement) or cancellation of this standard, a corresponding notice will be published in the monthly published information index "National Standards". Relevant information, notification and texts are also posted in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet

AMENDED, published in IUS N 11, 2007

Amended by database manufacturer

Introduction

In this standard, instead of referring to the international standard ISO 3715, replaced by two standards: ISO 3715-1 "Ships and ship technology - Ship propulsion systems - Part 1: Terms and definitions of propeller geometry" and ISO 3715-2 "Ships and ship technology . Part 2. Dictionary for propulsion systems with controllable pitch propellers", which are currently not accepted in the Russian Federation, a reference is made to GOST 25815, which covers the terms and definitions of marine propellers and meets the specific needs of shipbuilding in the Russian Federation.

Reference to ISO/R 468 is not included in this International Standard because this recommendation was replaced by ISO 468:1982 "Surface roughness - Parameters, their values and general rules for setting specifications", which was withdrawn without replacement in 1998.

The text of the individual structural elements changed in relation to the international standard ISO 484-1 in this standard is marked in italics.

1 Purpose

This standard specifies tolerances for the manufacture of marine propellers with a diameter of more than 2.5 m.

Note - In some cases, deviations of tolerances are possible at the request of the customer or by mutual agreement between the designer and the customer. Fixtures and measurement methods are chosen by the propeller manufacturer, provided that the tolerances are maintained with the required accuracy.

2 Scope

This standard applies to solid-cast propellers, propellers with detachable blades and controllable pitch propellers.

3 Normative references

This standard uses normative reference to the following interstate standard:

GOST 25815-83 Propellers. Terms and Definitions (ISO 3715-1:2002 "Ships and marine technology - Ship propulsion - Part 1: Propeller geometry terms and definitions", NEQ; ISO 3715-2:2001 "Ships and ship technology - Part 2: Vocabulary for propulsion systems with controllable pitch propellers", NEQ)

Note - When using this standard, it is advisable to check the effect of the reference standard in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or according to the annually published information index "National Standards", which was published as of January 1 of the current year , and according to the corresponding monthly published information signs published in the current year. If the reference standard is replaced (modified), then when using this standard, you should be guided by the replaced (modified) standard. If the referenced standard is canceled without replacement, the provision in which the reference to it is given applies to the extent that this reference is not affected.

4 Pitch measurement methods

4.1 The principle of one of the measurement methods is to draw on the arc the radius of the segment PQ, corresponding to the angle , and in the measurement of the height difference of the points R And Q relative to a plane perpendicular to the propeller axis (see Figure 1).

Picture 1

Line segment PQ shall be designed by one of the methods described in 4.1.1 or 4.1.2*.
________________
* If necessary, other methods can be applied to ensure the required accuracy.

4.1.1 Use of thickness gauges

Line segment PQ design with thickness gauges.

4.1.2 Graduated disk method

Cut length PQ is a characteristic of the angle on a part of a graduated disk of the corresponding radius (see Figure 1).

5 Section thickness measurement method

5.1 Thickness of a cylindrical section at a point S must be measured in the direction SV(see Figure 2), located in the tangential plane of the coaxial cylinder perpendicular to the step line of the discharge side of the section, and in the direction SU perpendicular to the surface of the discharge side or in the direction ST parallel to the axis of the propeller, provided that it is so defined on the drawing.

Figure 2

5.2 The maximum thickness for each radius should be determined using a pair of calipers or a profile obtained by construction at various points: S, S, S, S etc.

5.3 To check the incoming and outgoing edges, edge templates are used. The length of the edge templates must be at least 15% of the section length, but not less than 125 mm.

Leading and trailing edges should be checked with edge gauges for Class S and Class I propellers (see Table 1). For propellers of other classes, the test is carried out at the request of the customer.

Table 1


propeller class	Propeller class name
	Special
	Higher
	Average
	Ordinary

6 Propeller classes

The accuracy class is set by the customer in accordance with table 1.

7 Pitch tolerances

Tolerances per step are given in table 2.

table 2


Parameter name	propeller class

	, %
local step
Section step
Blade pitch
Screw pitch
Note - Limit deviations are expressed as a percentage of the design pitch of the corresponding radius for the local pitch and section pitch and the average design pitch for the blade pitch and propeller pitch

7.1 The pitch shall be measured at least at the radii given in Table 3.

Table 3


propeller class	Radii
	Section near the fillet of the hub: ; ; ; ; ; ;
	Section near the fillet of the hub: ; ; ; ;
	Section near the fillet of the hub: ; ;

By agreement between the interested parties, measurements can be taken at other radii.

7.2 Measurement of local pitches for propellers of classes S and I is carried out in accordance with clause 10.

7.3 Tolerances for local pitch and section pitch given in Table 2 are increased by 50% for sections of at or less.

7.4 The propeller manufacturer may compensate for a pitch error, the tolerance for which is given in Table 2, by changing the propeller diameter only with the consent of the purchaser.

7.5 The constructive step is the baseline step.

The line of the structural step of the section is a helical base line for the considered section, for which the ordinates of the section of the discharge and suction sides are given.

It can be a line connecting the nose and tail of the section, or it can be any other correspondingly located helical line.

7.6 Local pitch at a point IN(see figure 1) is determined by measuring the height difference between points R And Q, located at equal distances from the point IN, on both sides of it ( BP=BQ), and multiplying the height difference by . The result should be compared with the local pitch measured from the discharge side profiles for the same points.

The distance between any two points when measuring the local step can be from 100 to 400 mm. One pitch measurement should be taken near the leading edge, another close to the trailing edge, and at least two more pitch measurements in between. To the extent possible, measurements should be consistent.

7.7 The pitch of the section and the pitch of the blade are determined for each radius by multiplying the height difference between the measured extreme points by .

7.8 The blade pitch is determined as the arithmetic mean of the section pitches for the blade in question.

7.9 The propeller pitch is defined as the arithmetic mean of the average blade pitches.

8 Propeller Radius Tolerances

8.1 Propeller radius tolerances are given in Table 4.

Table 4


Parameter name	propeller class


propeller radius

8.2 For a propeller in a nozzle, these tolerances may be reduced.

9 Blade thickness tolerances

9.1 Thickness measurements should be taken at the same radii as the pitch measurements.

9.2 The limit deviations given in Table 5 are expressed as a percentage of the local thickness.

Table 5


Parameter name	propeller class

	Limit deviations (tolerance)
		mm, at least	mm, at least	mm, at least	mm, at least
Blade section thickness

9.3 The maximum thicknesses indicated on the drawing, after deducting a negative tolerance, shall not be less than the thicknesses required by the classification societies.

10 Smoothness tolerances for blade sections

Blade smoothness tolerances apply only to Class S and Class I propellers at the radii at which pitches are measured.

To achieve smooth sections, deviations as a result of successive measurements of the local pitch and thickness should not differ from one another by more than half the tolerance (for example, if the tolerance is from plus 2.0% to minus 2.0%, then the allowable difference in successive deviations is 2 .0%).

To avoid excessive deviations in the overall curvature of the section, it is necessary that the algebraic sum of the deviations, expressed as a percentage, of any two consecutive measurements of the local pitch exceed the prescribed tolerance by no more than 1.5 times. For example, if the tolerance is ±2.0%, then the sum of the successive deviations should be ±3.0% (see Figure 3).

Notes

1 In the figure, the deviations are increased by 20 times.

2 Very high values are underlined.

Figure 3 - Class I propeller

The smoothness of cylindrical sections is also checked using special flexible templates.

Incoming and outgoing edges should be checked with edge templates that allow you to establish the conformity of the edges with the drawing, taking into account the following tolerances of the discharge and suction sides:

±0.5 mm - for class S;

±0.75 mm - for class I.

By agreement between the manufacturer and the customer, the edges can be checked with edge gauges, consisting of three elements for each edge (see Figure 4), one element with a short nose to check the edge of the edge of the blade and two elements that are applied to the edge - one to the discharge, the other to the suction side. Each template covers approximately 20% of the blade length, but not more than 300 mm. These templates must be manufactured to a tolerance of 0.25 mm for class S and 0.35 mm for class I.

Figure 4

11 Blade length tolerances

11.1 The limit deviations given in Table 6 are expressed as a percentage of the ratio of the diameter to the number of blades ().

Table 6


Parameter name	propeller class

	Limit deviations (tolerance)
		mm, at least	mm, at least	mm, at least	mm, at least
Blade section length

11.2 The section lengths of each blade shall be measured at least at five radii for class S (for example: ; ; ; ; ) and at four radii for classes I, II, III.

12 Tolerances for the relative position of the blades, for the position of the center lines and for the contours of the blades

12.1 Position of the center lines of the blades

The center line is applied to the drawing as a straight line that passes through the point M on the discharge side of the blade and a point ABOUT on the axis of the propeller.

Dot M should be on a cylindrical section with a radius greater than and, if possible, close to .

The point is chosen so that the line OM crossed the largest possible number of sections of the blade.

The relationship between the angles (corresponding to the incoming edge) and (corresponding to the outgoing edge) is indicated on the drawing (see figure 5).

indicate the size on the drawing

Figure 5

point M" on the manufactured propeller, set in such a way that a ratio equal to the ratio indicated in the drawing can be achieved on the considered radius (see figure 6).

Figure 6

Reference planes passing through a point M", used to check the contour of the leading edge and tilt of the blades as well as the angular displacement of the blade*.
_________________
* Determination of tilt - according to GOST 25815 .

12.2 Tolerances on the contour of the leading edge

Tolerances shall be calculated for the radii given in Table 3 on the respective arcs and are valid for the length of the arc (see Figure 6). Tolerances, expressed as a percentage, are given in table 6 ( - diameter, - number of blades).

Tolerances for arc length should be equal to twice the values given in Table 6, provided that the contours of the blade edges are smooth.

12.3 Tolerances for angular misalignment between two adjacent blades

Permissions must be:

±1° - for screws of classes S and I;

±2° - for screws of classes II and III.

13 Tilt tolerances, position of the blade along the axis of the propeller and the relative position of the center lines of adjacent blades

The tilt is characterized by the position of the center line of the blade RR"(See Figure 7). The tilt is determined by measuring the distance to the plane W, perpendicular to the axis of rotation of the propeller, at least at points A, B And WITH located on radii or ; or ; or .

Figure 7

Table 7 shows the distance tolerances , and , expressed as a percentage of the propeller diameter , to check the position of the blades along the axis of the propeller. The same tolerances (rather than double tolerances) apply, for differences: for the same blade to check the tilt and - for two adjacent blades to check the relative axial position.

Table 7


Parameter name	propeller class

	Limit deviations, %
Blade position in points A, IN And WITH(located on radii ; and ) no with respect to the plane W, perpendicular to the axis of the screw

14 Surface treatment

Blade surface condition, expressed as the arithmetic mean of the deflection Ra,µm, should have a roughness not exceeding the following values:

3 (starting from the hub) - for class S propellers;

6 (starting from a radius of 0.3 ) - for class I propellers;

12 (starting from a radius of 0.4) - for class II propellers;

25 (starting from a radius of 0.5 ) - for class III propellers.

15 Static balancing

15.1 All manufactured propellers must be statically balanced.

The maximum allowable weight of the balancing weight, kg, applied at the end of the propeller blade, is determined by the formula:

Or , the smallest of them, (1)

Where - propeller weight, kg;

- outer radius of the blade, m;

- estimated number of propeller revolutions per minute, rpm;

And - coefficients depending on the propeller class are given in table 8.

Table 8


Coefficient designation	propeller class

16 Measuring instruments

The maximum permissible error of measuring instruments should not exceed half the tolerance for a size or parameter, and in the case of geometric measurements, 0.5 mm (the largest value is chosen).

Electronic text of the document
prepared by Kodeks JSC and verified against:
official publication
M.: Standartinform, 2007

Revision of the document, taking into account
changes and additions prepared
JSC "Kodeks"

home > Ideas