EA040564B1 - STEP CONTROL SYSTEM - Google Patents

Description

Technical field

The present invention relates to the field of rotary blade angle control systems.

State of the art

Turbomachines generally include one or more circular arrays of rotating blades. Such arrays include: axial fans, centrifugal fans, mixed fans, propellers, rotors and wind turbine blades. All such blades may have a fixed or variable pitch angle. Fixed pitch systems typically vary the rotation speed to obtain the required parameter values (eg speeds), while some variable pitch systems maintain an approximately constant rotation speed (eg helicopter rotors).

When using high-efficiency or energy-intensive turbines, it often makes sense to control both pitch and rotational speed to maximize aerodynamic efficiency, thrust, or another parameter of interest. In addition to optimizing performance, pitch control systems can address issues such as over-rotation.

Many existing pitch control systems are of rather poor quality. Pitch can be manually controlled by the person moving the lever, resulting in sub-optimal combinations of pitch and rotational speed. In the case of variable pitch propellers, the pilot can effectively set the propeller pitch once before takeoff and again during cruise flight. In this case, the pitch changes only twice within a few hours. If the pitch were to automatically and continuously change depending on the rotational speed throughout the flight, the benefits of such a mode could include reduced fuel consumption, increased range and flight duration.

Existing pitch control systems can automatically and continuously change the pitch of the blade. For example, helicopters use complex articulations, swashplates, and other mechanisms to cause a repeating blade pitch cycle. The pitch set cycle is used to control the roll and pitch of the helicopter. These pitch control systems only fit a narrow range of applications.

Existing advanced pitch control systems can continuously and automatically adjust the pitch of the blade even during the rotation speed change operation, but are not widely used due to their complexity and high cost. Many turbomachines can be advantageous by using a simpler and less expensive system that is suitable for small blades, including radio controlled aircraft propellers.

At present, advanced pitch control systems are almost exclusively applied to large and expensive turbomachines, including large wind turbines. In the case of large wind turbines, these systems usually include a separate motor for each blade. Each motor has a gear that is mated with teeth cut into the blade or part that is attached to the blade. The engine receives electrical commands from the on-board computer based on internal programs and data received from: anemometers, thermometers, tachometers and other sensors. Despite their functionality, such systems are also complex and expensive. An error or malfunction of any sensor can result in: degraded system performance, severe damage and/or complete shutdown of the wind turbine. Such systems are also susceptible to lightning strikes, power outages and other electrical system failures, as well as user errors that can occur when a person sends commands, changes settings, or updates software. Downtime can be costly as maintenance usually takes place on tall towers in remote locations. The state of the art, even for large turbomachines, can be improved by using a simpler and more reliable pitch control system.

Disclosure of the essence of the invention

The present invention provides a turbomachine pitch control system that solves the above problems of the prior art. The pitch control system (100) includes a bushing (12) with at least two housings (2) for the blade. Cases (2) for the blade are arranged in a circular array around the axis (40) of the bushing. The vane (1) interacts with each vane body (2) so that the vane (1) can move in a helical direction towards the hub axle (40) and away from the hub axle (40) along a segment of the helical path (43) to cause an angle change blade installation (1). The direction of the helix runs along the longitudinal axis (41) of the body. There is an imaginary plane (42) orthogonal to the axis (40) of the hub. The longitudinal axis of the housing (41) is oriented at an angle θ relative to an imaginary plane (42). The θ value is 30° or less.

One or more elastic elements (3) directly or indirectly attract the blade (2) to the axis (40) of the hub. The mechanism (4) for setting the pitch provides the ability to move the blade (1) in a spiral

- 1 040564 along the longitudinal axis (41) of the housing. The blade (1) is subjected to elastic and centrifugal forces. The elastic force is the result of the action of one or more elastic elements. The centrifugal force is the result of the rotation of the hub (12) which forces the blades (1) to rotate around the axle (40) of the hub. Each force has a counteracting component oriented in the longitudinal direction (41) of the body. The blade (1) moves in a direction away from the hub axle (40) when the centrifugal force component is greater than the elastic force component (ignoring other forces, including aerodynamic, gravitational and frictional forces). When the component of the centrifugal force is less than the component of the elastic force, the blade (1) is attracted to the axis (40) of the hub.

The pitch setting mechanism (4) includes a guide (5) that extends along a segment of the spiral path (43) and a part (6) associated with the guide, whereby the guide (5) and the guide part (6) associated with the guide are connected by coupled displacement relations , which include sliding or rolling along each other to enable the blade (1) to move in a spiral along the longitudinal axis (41) of the housing.

The housings (2) for the blade may have two side surfaces, i. e. inner side surface (44) and outer side surface (45). The butts (16) of the blades can also have two side surfaces: an inner side surface (46) and an outer side surface (47). There are two ways to make the guide (5) and the parts associated with the guide (6). According to the first method, the guides (5) can be placed on the side surface (44, 45) of the blade housing, while the part associated with the guide is located on the side surface (46, 47) of the blade butt. Alternatively, each guide can be located on the side surface (46, 47) of the butt of the blade, while the parts associated with the guide can be placed on the side surface (44, 45) of the blade housing. A set of bearings can be located on the butt (16) of the blade and / or housing (2) for the blade to reduce friction between the butt (16) of the blade and the housing (2) for the blade or between the guides (5) and associated with the guide parts (6) . The fairing (13) is located on the sleeve (12) and rotates around the axis (40) of the sleeve. Fairing (13) essentially has the shape of a dome or cone.

The elastic elements (3) are located inside the sleeve (12) and/or housing (2) for the blade. The elastic elements (3) can be directly or indirectly attached with one end to the butts (16) of the blade and the other end to the housings (2) for the blade, the sleeve (12), the shaft (10), the fairing (13) or the compensation mechanism (7) blade weight.

The outer diameter of the butt (16) of the blade may be smaller than the inner diameter of the bodies (2) for the blade, so that the butts (16) of the blade slide in their respective bodies (2) for the blade. According to another embodiment, the blade butts (16) may have inner diameters that are larger than the outer diameters of their respective blade housings (2), so that the blade butts (16) slide over their respective blade housings (2). The housings (2) for the blade may be wholly or partly contained within the hub (12) or wholly outside the hub (12).

The pitch control system may also include a blade weight compensation mechanism (7) that fully or partially resists the unbalanced effect of the blade weight on the longitudinal position of the blade housing relative to other blades. The blade weight compensation mechanism (7) comprises a guide element (8) and a part (9) coupled with the guide element. The guide element (8) is located around the axis (40) of the sleeve and forms a closed loop. The movement of the part (9) associated with the guide element around the guide element (8) is limited. The guide element (8) may have a non-circular cross section and/or may be vertically offset relative to the axis (40) of the sleeve.

In some implementations of the pitch control system, elastic elements (3) may be used, which are coil springs aligned with the longitudinal axis (41) of the housing. Elastic elements (3) pass through bushing (12), side wall (27), housing (2) for the blade and are connected at one end to the butt (16) of the blade and at the other end to the blade weight compensation mechanism (7).

In the preferred implementation of the pitch control system, a guide element (8) is used, the part (9) associated with the guide element of which is also concentric with the guide element (8) and the axis (40) of the bushing. The part (9) associated with the guide element rotates around the guide element (8). In the preferred embodiment, an elastic element (3) is used, which is a torsion spring (48), which surrounds the inner part or the outer part of the guide element (8) and is attached to the part (9) associated with the guide element.

In a preferred embodiment, rods (19) are also used, arranged in a circular array around the axis (40) of the sleeve. Each rod has two ends. One end is located inside the butt (16) of the blade or body (2) of the blade and is directly or indirectly connected to the butts (16) of the blades. The other end passes through the side wall (27) into the sleeve (12) where it is pivotally connected to one end of the lever (24). The other end of the lever (24) is pivotally connected to the part (9) conjugated with the guide element. The insert (22) is used to reduce friction between the rod (19) and the side

- 2 040564 wall (27) of the bushing, when the rod (19) slides into and out of the bushing. The bearing (20) is used to reduce friction when the blade (1) rotates relative to the rod (19).

Compared to the prior art, the advantages of the present invention are:

1) wide applicability;

2) simplicity;

3) low cost;

4) low operating costs;

5) durability;

6) reliability that is not affected by:

a. power loss;

b. malfunctions of electronic means;

c. sensor errors; or

d. user errors.

Brief description of several views in the drawings

In FIG. 1A shows the pitch control system of a three-blade propeller or turbine with main plane and axes.

In FIG. 1B shows a predetermined range of angles limiting the angular deflection of the housings for the blade.

In FIG. 2 shows a pitch control system attached to a motor.

In FIG. 3 shows a pitch control system with a housing surrounding a motor or generator.

In FIG. 4 is an enlarged view of a single blade and blade housing for Embodiment A.

In FIG. 5 is an exploded 3D view of Embodiment A.

In FIG. 6 shows a transparent exploded 3D view of Embodiment A.

In FIG. 7 shows an alternative form of Embodiment A where the blade butt slides over the blade body.

In FIG. 8 shows guides on the butt of the blade and coupled with the guide part on the housing for the blade.

In FIG. 9 shows low-friction mated guide parts.

In FIG. 10 shows embodiment A with blade housings inside the hub.

In FIG. 11 shows an alternative holding part for Embodiment A.

In FIG. 12 is a sectional view of Embodiment B with a blade weight compensation mechanism.

In FIG. 13 shows the engine cover for Embodiment B.

In FIG. 14 shows an exemplary engine for Embodiment B.

In FIG. 15 shows the assembled blade and blade housing for Embodiment B.

In FIG. 16 is an exploded view of the details of the blade and blade housing for Embodiment B.

In FIG. 17 is a three-dimensional view of an exemplary guide member-associated portion.

In FIG. 18 shows exemplary guide elements.

In FIG. 19 is a sectional view of the guide elements.

In FIG. 20 is an exploded view of the guide elements.

In FIG. 21 shows the guide elements and the parts associated with the guide element, installed in place.

In FIG. 22 is a transparent front view of the guide elements with their mating portions, clearly showing the non-circular shape and the vertical offset of the guide element.

In FIG. 23 shows elastic elements attached to the parts mating with the guide element.

In FIG. 24 shows the ground and hull coordinate systems for the blade.

In FIG. 25 shows the important forces and moments to which the blade is subjected.

In FIG. 26 shows the orthogonal coordinate system used to display the normal and binormal.

In FIG. 27 shows the coordinate system associated with the guide relative to the coordinate system associated with the sleeve.

In FIG. 28 shows embodiment C with the fairing removed.

In FIG. 29 is an exploded view of a blade and blade housing according to Embodiment C.

In FIG. 30 is another exploded view of a blade and blade housing according to Embodiment C.

- 3 040564

In FIG. 31 is a sectional view of an assembled Embodiment C.

In FIG. 32 is an exploded view of the parts inside the sleeve for Embodiment C.

In FIG. 33 shows a segment of the spiral path on the outer side surface of the butt of the blade with a guide cut out along the indicated path.

Implementation of the invention

Dynamics.

The blades are mounted in housings for the blade, which are located in the sleeve along its circumference. All rotating blades are subjected to centrifugal force, which is proportional to the square of the speed of rotation of the hub. The higher the rotation speed, the greater the centrifugal force that separates the blade from the hub. The centrifugal force is counteracted by an elastic element. For discussion, it is temporarily assumed that the elastic element is a linear spring, which stretches with increasing rotation speed. When the spring is stretched, the blade is forced to rotate around its longitudinal axis, moving along the guides with its reciprocal paired with the specified guide parts. The guide mating portions can be configured to hard increase the pitch as the rotation speed increases (in the case of a propeller) or increase the pitch beyond the safe zone (in the case of a turbine) and then decrease and/or zero the pitch if the rotation speed becomes too high.

The pitch control system is designed in a non-trivial way of design that a person skilled in the art may not immediately understand. To analyze the dynamics and behavior in order to facilitate the appropriate design of the structure for a given application, a dynamic system model must be created. To illustrate this method, an exemplary dynamic model of rotation of the hub at constant speed in a vertical plane with the weight of the blade as a weight according to embodiment B is built. This model can be easily adjusted to function without taking into account the weight of the blade (according to embodiment A) and can provide insight into modeling various other pitch control system implementations, including implementation C.

To do this, it is useful to form a coordinate system associated with the Earth (terrestrial coordinate system) and a coordinate system associated with the hub (hub coordinate system). XYZ is the ground coordinate system and xyz is the coordinate system associated with the hub, as shown in FIG. 24. The center of both systems is defined at the point where the center lines of the housings for the blade intersect. The x-axis is vertical, the y-axis exits the page, and the z-axis is horizontal. The y and y axes are always collinear, but the x and z axes change their orientation when the hub is rotated through some angle β, so that the z axis always runs along the centerline of one blade housing.

The forces and moments applied to a blade should be considered in detail in order to model and understand its movement, including its response to disturbances. Such forces are due to aerodynamics, gravity, interactions between guides and associated with said guides, centrifugal force, elastic force and interactions between the blade and the housing for the blade. In order to understand these forces and moments, the free body diagram shown in FIG. 25.

There are four key points: A, C, R and G. Point A is the aerodynamic focus of the blade, and at this point an aerodynamic force and moment ( ^W “) are applied to the blade

It is assumed that the aerodynamic force acting in the z direction is negligible, as are the aerodynamic moments around the x and y axes.

Point C is the center of mass of the blade, and at this point centrifugal force (£) and force (due to the weight of the blade) are applied to the blade. The weight of the blade during its rotation can act in various coordinate directions associated with the sleeve. Unfortunately, the indicated weight generally acts in the xz plane and contributes to the force acting in the z-direction, which results in a cycling of the blade retraction force, which ultimately determines the pitch angle of each blade.As the pitch angle of each blade is cycling, there will be a cycling of all applied forces and The blade weight compensation mechanism is designed to correct for this effect by pushing the blade out when it is at the top of its rotation cycle and pulling the blade in when it is at the bottom of its cycle. z will not depend on its angular position, i.e. the angle β, but only on the speed of rotation of the sleeve. Mathematically, it is possible to simulate the operation of the blade weight compensation mechanism by changing the free length z _s0 of the spring as a function of the angle β.

An important question is whether the additional costs and complications associated with the blade weight compensation mechanism can be avoided. The weight of the blade is constant, while the centrifugal force is proportional to the square of the rotational speed of the hub, so at high rotational speeds the centrifugal force will dominate the weight. In addition, the effect of the weight of the blade can

- 4 040564 be reduced by designing the blades with increasing mass densities towards the tips of the blades, which will also increase the centrifugal force relative to the weight. To avoid resonance, the system can be designed so that its natural frequencies are outside the range of rotational speeds. Adjustable system damping can also be applied. A simple point mass can be considered, rotating in a vertical plane, connected by a string to its center of rotation. When the point mass is at its lowest position, centrifugal force and weight act in the same direction, in which case the tensile stress in the string is:

F _r = m-(i ² l+g)· where l is the length of the string and g is the gravitational acceleration.

For a small unmanned aerial vehicle (UAV), the propeller radius may be 0.1 m, which corresponds to a string length of approximately 0.035 m. avoid these frequencies as natural frequencies of the system. For the case of a small UAV modeled as a mass and a string, gravity is between 1.6 and 4.5% of the centrifugal force over the entire range of hub rotation speeds. For this case, the pitch fluctuation will be small, so it may be appropriate to eliminate the blade weight compensation mechanism altogether. All systems that rotate in a horizontal plane, or that operate in an environment without gravity, will work fine without a blade weight compensation mechanism. As another example, consider a typical large wind turbine rotating in a vertical plane at a speed of 1.05 rad/s and having blades 40 m long and weighing 5500 kg. In this case, gravity is 67% of the centrifugal force, so a blade weight compensation mechanism is required.

Point R is the point at which the reaction force and moment are assumed to be applied. In reality, the distribution of reaction forces across the blade butts depends on the details of the interaction between the housing and the butt, presumably through one or more bearings, which facilitate smooth movement of the blade roots relative to the blade housings. In this example, point R is depicted on the outer edge of the housing for the blade in the center of its circular cross section. If details are omitted, the position of the R point becomes somewhat arbitrary, since the exact system of forces and reaction moments can be determined for any intended application point. The reaction force and moment in the direction of the z-axis is considered negligible (with good lubrication and no friction). The elastic force also passes through point R as a geometric result.

The last key point is point G. It is located in the center of the circular cross section in the plane of the parts mating with the guides. By separating the reaction forces and the forces acting on the guiding mating part, the guiding mating parts can be designed appropriately to withstand the applied loads. In this example, the forces “(K) applied to the mating parts of the guide are modeled as one force a applied at point G, with the corresponding moment ^s ^'

Guides and their associated parts can be designed in many different ways. In FIG. 26 shows an example in which it is assumed that the depth of the guide is sufficient to prevent the tips of the parts mating with said guide from touching the base of the respective guides. As a result, there is no force applied to the parts mated with the guide in the direction of the binormal to the specified guide,

In addition, friction can be neglected, so that there is no force acting on the part mating with the guide in the direction of the tangent to said guide, ^f

Thus, the guides are modeled taking into account the forces applied to the mating parts of the guide, acting only in the direction normal to the specified guide.

W = fs ^d d ^d d ⁿ as shown in fig. 26.

- 5 040564

It is assumed that the blade is absolutely rigid, and the equalities describing the movement are derived as follows:

3, ^ax r Ux F ^dx r ^- ®

b. Fay + Fry Fgy - ⁰ _with P + F _s + F _gz + W _z \u003d mz d. ~ Fay (¾ ^- Zr) + Fgy (z _R - Zg) + = 0

e. Fax (¾ - z^-F^ (z _R - z _c ) + W _x (z _c - Z _R } + Af^ = 0 f ^az + + ^gz ⁼ ^z

The six equalities describing displacement have eight unknowns:

Fgx , Fgy , Mgz _f F _r x , Fry _ff M _ry .

but more equalities can be written relating to the interactions of rollers with guide elements:

g. Fgx \u003d F _g O h. Fgy - F _g (<? _Ώ J)

i. Fgz Fg {Pg F)

Three new equalities are written with four new unknowns, represented as:

Fg , (e _and -0, (^-L , ( ^e p ' , but the value ⁷¹ will be determined during the guide design process. Later, the quantities Fgx, F _gy and F _gz will become functions of one unknown quantity Fg, and then there will be nine equalities with nine unknowns, which are a solvable system with a unique solution.

The design of the guide is new to this particular invention. In this case, it is convenient to form a coordinate system with index d that starts at the inner edge of the guide, so that z=z _g +z _g0 as shown in FIG. 27. In this example, each guide extends at a constant radial distance from the centerline of the blade body, making it convenient to use cylindrical coordinates.

i rt \u003d ^g pM + ^g p ^w 6 _a e _c + zk g \u003d constant

I

Τ'

The value of ^p can be expressed as a function of one variable z _g , where said function θ _g (z _g ) determines the angle of the blade when it is brought to a particular position z _g . For a particular blade design operating in a particular environment, several optimal rotation speed/pitch combinations can be calculated. To obtain the value of θ _g (z _g ) to the optimal points of combinations of rotational speed/step in the specified area can be applied to the curve drawing point by point. Converting back to the base Cartesian coordinate system associated with the hub results in a usable description of the specified guide element: k.mM) = + M + zk

Then, the length s of the guide curve is determined as a function of z.

Introducing the relations dx, ds, -j— - x. , -s ,etc az az

- 6 040564 you can define a unit normal vector as:

r ^! s' -r ^f s ^!

The centrifugal force is modeled as:

m is the mass of the blade;

$ - sleeve rotation speed; and zc is the location of the center of mass of the blade, which is a function of β.

If the hub rotates in a vertical plane, the weight of the blade will not contain a y-component. In this case, the force created by the weight in the coordinate system associated with the hub will depend on the angle of rotation of the blade as follows:

₀ w _x \u003d -w-ass _P W _z \u003d -W-cosfe)

If the resilient element is assumed to be a spring that has a linear response over its entire operating range, the force it applies to the blade can be modeled as:

q. K - where:

k _s - linear coefficient of spring stiffness; and z _s0 is the position of the blade rollers on the z axis, corresponding to zero compression or elongation of the spring.

The value of z _s0 is designed to compensate for the weight W _{z of} the blade in the direction of the z axis; it becomes a known function of the rotation angle β of the sleeve. Changing the blade angle causes twisting as well as elongation of the spring. If (1) the spring moment is significant, (2) the coupling is negligible, and (3) the torque-induced moment is linear, then:

m) = (e - e _s0 )k where:

T _s - torsional spring constant; and θ _s0 is the installation angle corresponding to zero twist of the spring.

With the above in mind, the net reaction force and moment applied to the blade can be determined using the displacement equations derived above.

It should be remembered that the movement of the blades along the housings causes changes in the diameter of the disk formed by the rotating blades, and, consequently, the speed due to rotation in a particular section of the blade. If the displacement is significant, these aerodynamic effects in the above models may not be negligible. In this case, particular attention must be paid to the aerodynamic forces and moments applied to the blade, and changes in the area of the disk formed by the rotating blades must also be taken into account.

Design.

Three exemplary embodiments are presented to describe various designs for a pitch control system. All the embodiments of the pitch control system given as an example contain: blades (1), housings (2) for the blades, elastic elements (3), mechanisms (4) for setting the pitch with guides (5) and associated with the guide parts (6), shaft (10), bushing (12), fairing (13) and motor (14). The two exemplary embodiments comprise a blade weight compensation mechanism (7) with guide elements (8) and parts (9) associated with the guide elements.

The bushing, blade housings and blades are rotated by the shaft. The centripetal force is required to support the circular movement of the blades, provided by the elastic element, which is directly or indirectly connected to each blade. The higher the speed of rotation of the shaft, the greater the stretching of the elastic elements and the greater the movement of the blades in the outward direction.

The pitch change mechanisms convert the longitudinal movement of the blade into a change in the angle of the blade by directing the blade to angular rotation of the blades about their longitudinal axes whenever the blades are moved in their longitudinal directions. To achieve this effect, guides are made in the blade bodies or in the butts of the blades. The corresponding parts associated with the guides are placed in the butts of the blades or in the blade housings. Mated with rails

- 7 040564 These parts are forced to move by said guides in such a way that for each speed of rotation the required setting of the blade angle is achieved. Depending on the application, the pitch change mechanisms can be designed to maximize aerodynamic efficiency by maintaining the optimal combination of blade angle and rotational speed. In yet another embodiment, these pitch change mechanisms can be designed to allow the motor to have a narrower range of rotational speeds while still providing a wider range of flow rates. For turbines, pitch change mechanisms can provide over-rotation protection by reducing the blade angle when the rotation speed becomes excessive. Blade angle adjustment mechanisms are usually designed to increase the pitch as the blade speed increases. In these cases, with the linear movement of each blade in the outward direction, its installation angle gradually increases. Conversely, as each blade moves inward linearly, its pitch angle gradually decreases.

In FIG. 33 shows three exemplary guides (5) placed on the outer side surface of the butt (47) of the blade, which follow the helical path segment (43). The exemplary guides have a mounting section (55) that allows them to slide over the guide-mating parts (6) located on the inner side surface of the corresponding blade housing (2). The exemplary guides have a pitch increase section (53) which causes the pitch to increase as the rotation speed increases. When the rotational speed approaches its safety threshold, the blades continue to move outward, but their pitch angle is reduced due to the pitch reduction section (54).

When the shaft rotates at a constant speed, the resulting force and moment acting on each blade become balanced, and each blade realizes a state of uniform circular motion around the said shaft. Each blade, properly designed and built, travels an approximately equivalent pitch distance and rotates an approximately equivalent pitch angle. The inertial and aerodynamic forces are reasonably and well balanced across the entire disk formed by the rotating blades and there is little tendency to induce vibration. A blade weight compensation mechanism is not required for systems in which the axis of the disk formed by the rotating blades (hub axis) is oriented vertically (parallel to the gravity vector) or systems with high rotational speeds. Examples of such systems include helicopters with multiple rotors of any size (vertically oriented discs formed by rotating blades) and propellers (high speed rotation) of small radio controlled (RC) aircraft.

Implementation option A.

A plurality of housings (2) for the blade are arranged along the circumference of the hub (12), as shown in FIG. 1. The fairing (13) is attached to the hub. The sleeve (12) is attached to the motor (14) as shown in FIG. 2. A gearbox can be located between the motor and the hub. The motor hub mounting method may include a collet, screw-on plate, or other mechanism. Motors are usually covered with covers (15) as shown in fig. 3.

The housings (2) for the blade make it possible to install the blades (1) around the hub. The housings (2) for the blade according to the embodiments shown have mounting holes (28) for the blades (1). The housings for the blade and the butt of the blade (16) may be in the form of cylindrical tubes. The blade housings do not restrict the movement of their respective blades in their substantially longitudinal direction. The movement of the blades relative to the bodies resembles the extension or retraction of a classical telescope. A radial linear bearing, lubricant, or other friction reducing agent may be used to help smooth movement of the blades relative to the blade housings. If the outer diameter of the blade root is smaller than the inner diameter of the blade housings, the blade root can slide in the blade housings as shown in FIG. 4.

For implementation variant A, the elastic element (3) is shown as a coil spring. Each end plate of the elastic element has a hole (as shown in Fig. 5) for threaded fasteners. The butt of the blade (as shown in Fig. 6) and the sleeve also have holes for these fasteners. One end of each elastic element is connected to the butt of the blade, and its other end is connected to the sleeve. Elastic elements pass through the center of the housings for the blade and the center of the butts of the blades. The inner side surfaces of the butts of the blades and housings (46, 44) for the blades prevent bending of the elastic elements when they are compressed. The guides are arranged circumferentially along the inner side surfaces of the housings for the blade. They are shown as grooves cut into the inner side surface.

Conjugated with the guide part (6) are shown as a circular array of protruding elements that surround the butt of the blade. As the butt of the blade slides in the blade housing, the guide mating portions slide in the guides. The threaded fastener is used to bolt the unattached end of the elastic element to the blade housing (2) or the side wall (27) of the hub from the inside of the hub, as shown in FIG. 6.

After the blades are installed in the blade housings, holding parts (11) are installed to prevent said blades from slipping out of the blade housings. An exemplary holding portion is shown as a flexible ring with a slit across it so that it can be opened by stretching, positioned at the open end of the blade housing, and attached with threaded fasteners. This ring covers the open end of the guides.

In FIG. 7 shows an alternative version of Embodiment A in which the inner diameter of the butts of the blades is larger than the outer diameter of the blade housings so that the butts of the blades slide over the blade housings.

The holding part may consist of two separate parts which are combined and screwed to the open end of the butts of the blades, as shown in fig. 8. Guides do not have to be located on the housings for the blade; they can also be made in the butts of the blades. When the guides are made in the butts of the blades, the parts associated with the guides must be placed on the housings for the blade, which is also shown in Fig. 8.

The guide mating portions may include two circular arrays located at different longitudinal locations around the blade root or blade housing as shown in FIG. 8 and 9. The longitudinal separation of the two circular arrays maintains blade flex, prevents wedging between the blade butts and housings, prevents the inner and outer travel surfaces from making direct contact with each other, and allows the user to avoid the use of radial linear bearings. The cross-sectional shape of the butt of the blade and the housings for the blade does not have to be round, provided that the gap between the blades and the housings for the blade is sufficiently large.

In FIG. 9 shows a unique custom built friction reducing system. Its guiding parts have two bearings: one normal bearing (17) and one binormal bearing (18). A normal bearing rotates about an axis that is perpendicular to the axis of a binormal bearing. The binormal bearing is located inside the normal bearing and contacts the bottom of the grooved guides during use. The binormal bearings are angled to allow tangential rolling along the guides without binding. Normal bearings are slightly smaller than the width of grooved guides. As a result, they come into contact with only one wall of the guides at a given time and thus rotate without jamming. Binormal bearings do not have to be placed in the center of normal bearings; they can also be made completely separate.

Vane housings are typically blunt objects that can cause flow separation and turbulence when exposed to fluid flow. For turbomachines with small hub to blade ratios, the housings for the blade will protrude from the hub and be affected by the flow, but the associated adverse effects of the flow will be minimal. For turbomachines with a large hub-to-vane ratio, the housings for the blade may be partially or completely enclosed by the hub, as shown in FIG. 10. In this case, they are not exposed to external flow, thereby reducing flow separation, wake turbulence and aerodynamic drag of the housings for the blade.

The blades used can be of any type, including axial fan blades (FIG. 10). Guides can be cut along the entire body for the blade. In addition, the retaining part may consist of a snap ring placed inside the sleeve, as shown in FIG. eleven.

Option In implementation.

In some applications, it is necessary to use a blade weight compensation mechanism to counteract the blade weight component acting in the longitudinal direction of the housing for said blade. The blade weight compensation mechanism can counteract this component regardless of the angle of rotation of the blade around the shaft. The need for a blade weight compensation mechanism increases with the weight of each blade and the degree of closeness of the hub axis orientation to the horizontal (perpendicular to the direction of the gravity vector). The need for a blade weight compensation mechanism decreases with increasing hub rotation speed and is eliminated altogether when the hub axis is vertical (parallel to the direction of the gravity vector). The blade weight compensation mechanism of Embodiment B is not suitable for applications where the orientation of the disk formed by the rotating blades varies greatly (eg, in the case of a full scale propeller-driven fighter aircraft).

In FIG. 12 shows variant In the implementation. Inside the housing (15) is placed the engine (14). The engine and engine housing are shown in Fig. 13 and 14 respectively. In this exemplary embodiment, the rear wall (26) of the sleeve (12) is bolted to a plate that is welded to the motor shaft (10). In general, there are many different ways of fastening the sleeve to the shaft, any of which can be used. According to embodiment B, the fairing (13) is attached to the side wall (27) of the sleeve along the circumference of its peripheral region using threaded fasteners. The housings for the blade can be made with a rear wall and a side wall in one piece. According to another embodiment, the blade housings may be made separately and then attached to the side wall by means of threads made on the outer side surfaces of the blade housings, with the corresponding threaded holes in the side wall. Many other methods are known for attaching the side wall of the hub to custom blade housings, including using an array of fasteners or bonding with adhesive. Regardless of the method used, precautions must be taken to ensure that the blade housing and guides are properly oriented after assembly.

In embodiment B, the parts (9) associated with the guide element are shown as rollers, as shown in FIG. 15. They are attached to the resilient members using a plurality of bolts as shown in FIG. 16. Other methods of fastening are equally applicable. Embodiment B contains eight wheels (as depicted in FIG. 17), but more or fewer wheels may be used. For embodiments like Embodiment B, it is recommended to include at least four wheels in the guiding element mating part.

The guide element (8) of the blade weight compensation mechanism forms closed contours, which do not have to be round (as shown in Fig. 18). For the embodiment shown in the drawing, the guide element is two parallel rectangular channels formed by three concentric parts (as shown in Fig. 19), which also need not be round. The rearmost concentric portion is attached to the engine housing by means of threaded fasteners. Each concentric part has a plurality of holes located around its peripheral region, through which it is fastened together with other concentric parts (as shown in Fig. 20). The parts mating with the guide element are placed inside the guide elements while fastening said three concentric parts of the guide elements (8) together (as shown in Fig. 21). Parts mating with the guide element can only move within the channels of the guide element and cannot be removed from the channels of the guide element without dismantling said concentric parts (as shown in Fig. 22). The guide element is vertically displaced in the direction from the hub axis, and for each blade there is one part associated with the guide element.

The elastic elements (3) are cylindrical springs, which are attached at one end to the parts (9) mated with the guide element (as shown in Fig. 23) and at the other end to the butts (16) of the blades using threaded fasteners. The blades (1) are held in the housings (2) for the blade using the retaining parts (11) as in embodiment A of the implementation.

The sleeve has a through hole, the diameter of which is equal to the inner diameter of the cylindrical housings for the blade (as shown in Fig. 12, 16). In embodiment B, the resilient elements are shown as springs that pass through an opening in the side wall and the blade housing for connection to the butts of the blades. It should be noted that the housing for the blade also extends inwardly towards the guide elements, which prevents the resilient elements from buckling during compression. This design also prevents lateral deformation of the elastic elements in the gap between the guide element and the side wall.

Since the parts mating with the guide element are forced to move only along the guide element, one end of each elastic element is also forced to move along the guide element. This leads to the movement of the inner end of the elastic elements during the rotation of the shaft. The movement of the inner end of the elastic elements is designed to counteract the weight of each blade acting in its longitudinal direction.

The blades periodically rotate with the shaft while their weight vectors point down. The weight vector component may point in the longitudinal direction of the blade and be added to or subtracted from the centrifugal force vector. As a result, there is an undesirable periodic contribution of the weight of the blade to the centrifugal force.

When the axis of the disk formed by the rotating blades is horizontal (perpendicular to the weight vector) and the blade is at its lowest position, the weight of the blade is added to the centrifugal force, causing excessive tensile deformation of the elastic member attached to it. The result is that the blade will move too far down. To counteract this, the guide element forces the inner end of the elastic element to move upward towards the axis of the sleeve (as shown in Fig. 22). The opposite action occurs when the blade is at the top of its rotation cycle and its weight is acting against the centrifugal force. In this case, the tensile deformation of the elastic element is insufficient, so that the blade will not move upward significantly. To compensate for this effect, the guide element forces the inner end of the elastic element to move upwards away from the hub axis. The axis of the sleeve is collinear to the shaft.

Option C implementation.

Implementation C uses additional parts including: rods (19), bearings (20), stops (21), bushings (22), connector (23), levers (24) and pins (25). A general perspective view of embodiment C without fairing is shown in FIG. 28.

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According to implementation variant C, the blades (1) and the blade housings (2) are combined as follows: sleeve-like guides (5) manufactured separately are inserted into the blade housings (2). Said guides have one or more keys (29) and the blade housings have one or more key slots (30). The keys and key slots mate with each other to prevent relative rotation between guides and housings for the blade, as shown in FIG. 29.

The rod (19) is inserted into the bearing (20) and passes through the stop (21). The bearing is located in a recess made in the limiter. The stopper is threaded around its peripheral region. The butt (16) of each blade is threaded along its cylindrical inner surface, as shown in FIG. 30. The limiter (21) is screwed into the butt (16) of the blade to connect the rod (19) and bearing (20) with the butt of the blade. The bearing (20) is a thrust bearing; the rod (19) can slide along the longitudinal direction of the blade, and the rod (19) has a head at one end that prevents it from completely leaving the butt of the blade, bearing and limiter. The depth of the butt of the blade is insufficient to enable the rod to move too far inward. At the other end of each rod there is a hole for a pin (25) for subsequent connection with the levers (24), as shown in Fig. 31.

There is a hole in the back of each blade housing. The hole passes through the side wall (27) of the sleeve (12). An insert (22) is installed in each hole. The butt blades are paired with the guide part (6), which slide in the guides (5). At the same time, said rods slide through the bushings and the side wall into the inside of the sleeve. A retaining part (11) in the form of a spring retaining ring is installed in the outer part of each blade housing for locking the sleeve-shaped guide and blade root corresponding to it. The free end of each rod (19) is attached to one end of each lever (24).

Embodiment C has a blade weight compensation mechanism (7) as shown in FIG. 28. It has only one guide element (8) which is essentially a rod or tube located in the center of the bushing and aligned with the axis of rotation of the bushing. The tubular guide element extends outwardly from the inner surface of the rear wall (26). There is only one part (9) associated with the guide element, which is also essentially tubular or annular; it is slipped over the guide element until it stops on a small ledge at the bottom of the guide element. The guide element and the portion conjugated with the guide element are concentric.

The elastic element (3) in the form of a helical torsion spring is slid onto the guide element and surrounds it. According to another implementation variant, the elastic element can be slipped over the part conjugated with the guide element. The elastic element is attached at one end to the guide element and at the other end to the part conjugated with the guide element. The part conjugated with the guide element is made with the possibility of rotation around the guide element, but without the possibility of moving along it. The elastic element resists the rotation of the part associated with the guide element.

The part mating with the guide element has connecting parts (31) arranged around it, as shown in FIG. 32. One end of each lever is attached to the connecting parts, and its other end is attached to the rod. The pin connections enable each lever to rotate flatly with respect to its respective guide element mating part and the stem. The pins (25) of Embodiment C may be cotter pins having a single head (as shown in FIG. 32).

The upper inner surface of the tubular guide is threaded to facilitate installation of the fairing (13). The fairing is mated with the upper side of the hub and is coaxial with the hub. The fairing has a central tubular connector (23) that protrudes inward from the center of its inner domed or conical surface. The connector (23) is threaded at one end to allow the fairing to be screwed into the guide. According to another embodiment, the connector may have an inner diameter that is larger than the diameter of the guide element for screwing over the guide element. There is a ledge passing around the peripheral part of the open end of the fairing (13). Said ledge is associated with a ledge extending along the open end of the side wall (27) to provide a smooth continuous surface between the fairing and the side wall.

As the hub rotates, a torque is applied to the fairing that tends to tighten the fairing. At the same time, centrifugal forces pull the blades outward, which causes the rods to move outward. Said movement in the outward direction is converted by means of the attached levers into rotation of the portion associated with the guide element. Said movement in the outward direction stops when the balance of moments around the part associated with the guide element is reached. The balance occurs between the moment resulting from the deformation of the elastic element, and the moment resulting from the centrifugal forces applied to the blades.

All three blades are mechanically forced to have the same installation angle at the same

- 11 040564 rotation speed regardless of the weight of the blade or its orientation. The blades at the bottom of the disk formed by their rotation increase the outward force. At the same time, the other blades at the top of the disk formed by their rotation reduce the outward force. In this way, the effect of the weight of the blade is automatically compensated regardless of the angle of inclination of the disk formed by the rotating blades or the local acceleration of gravity. This mechanism will work equally well in outer space, on Mars, in the horizontal plane, the vertical plane, or any plane in between. The blade weight compensation unit according to Embodiment C mechanically forces all the blades to move the same longitudinal distance and have the same pitch angle at a given time. If excessive friction occurs in one of the guides, the corresponding blade will not deviate from the angle of the other blades.

The pitch control system described uses a simple mechanical device that is not affected by power outages, sensor errors, or user error. This approach increases the reliability of the system. The general design is quite simple. Manufacturing and maintenance costs are expected to be reasonably low.

Although the foregoing written description of the present invention provides an opportunity for a person skilled in the art to make and use what is currently considered the best mode of the present invention, those skilled in the art will understand and appreciate possible variations, combinations and equivalents of this particular embodiment, method and examples. presented in this document. Thus, the present invention should not be limited to the above-described embodiments, methods and examples, but includes all embodiments and methods within the scope and principle of the present invention.

(1) Definitions.

The term shaft refers to the shaft around which the hub and blades rotate. This shaft may be connected to the motor directly or through a gearbox or other set of gears.

The term engine for the purposes of this patent is interpreted to include engines, machines and generators. The motor drives the rotating vanes or is driven by the rotating vanes.

The term resilient element refers to any elastic part or set of parts connected directly or indirectly to the blades, which can resist movement of the blades relative to the blade housings.

The term guide refers to any guide, slot, slot, channel, track, bus, link, bar, or other device that forces properly designed guide mating portions to move along it. The term guide is specifically applicable to pitch setting mechanisms.

The term "guided part" refers to any protruding part, pin, tongue, roller, wheel, slider, ring, or other device capable of mating with a rail to force movement along said rail. The term guide mating part is specifically applicable to pitch setting mechanisms.

The term guiding element refers to any guiding element, groove, slot, channel, track, rail, bar, rod, pipe, or other device capable of forcing properly designed parts mating with the guiding element to move along it. The term guide member is specifically applicable to the weight compensation mechanisms of a blade.

The term guiding member refers to any protrusion, tongue, roller, wheel, slider, collar, tube, or other device that is configured to mate with the guiding member to force movement along said guiding member. The term guiding member part is specifically applicable to the weight compensation mechanisms of the blade.

The term retaining portion refers to any portion that prevents the blades from moving outwardly far enough to slide out of or exit their respective blade housings. The holding portions are not necessarily annular.

The term pitch mechanism refers to any mechanism or set of mechanisms used to cause the blades to establish a pitch angle as they move relative to the blade housings.

The term blade weight compensation mechanism refers to a set of parts that partially or completely counteracts the effect of the weight of the blade on the pitch setting of the blade.

The terms helical and helical refer to a curve or movement along a curve formed by any line drawn on a plane when that plane is wrapped around a cylindrical surface.

The term any line includes lines that are curved and/or have discontinuous (not smooth) derivatives.

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Claims (12)

The terms cylindrical, cylinder, and cylindric should not be construed as a limitation to straight, solid, or circular cylinders. 1. System (100) step control, containing: (a) sleeve (12); (b) housing (2) for the blade, located on the sleeve (12) around the axis (40) of the sleeve; (c) a blade (1) cooperating with the housing (2) for the blade, (a) movable in a spiral to and from the axis (40) of the hub along a segment of the spiral path (43) to cause a change in the angle of installation of the blade (1 ), and the direction of the spiral runs along the longitudinal axis (41) of the housing; (b) where there are at least two blades (1) and two housings (2) for the blade; - 13 040564 (d) elastic element (3), directly or indirectly attracting the blade (1) to the axis (40) of the bushing; and (e) a pitch setting mechanism (4) configured to facilitate the movement of the blade (1) in a spiral around the longitudinal axis (41) of the housing: (a) in the direction away from the axis (40) of the hub, if, without taking into account other forces, the centrifugal force is greater than the opposing elastic force in the longitudinal direction (41) of the housing, when both forces are applied to the blade (1), and when the centrifugal force is the result of rotation bushings (12), and the elastic force is the result of the action of one or more elastic elements (3); or (b) in the direction towards the axis (40) of the sleeve, if, without taking into account other forces, the specified centrifugal force is less than the specified elastic force acting in the longitudinal direction (41) of the housing, while the pitch setting mechanism (4) contains a guide (5) , which extends along the spiral path segment; and a part (6) associated with the guide, and between the guide (5) and the part (6) associated with it, there is a relation of associated movement, which includes sliding or rolling along each other, to enable the blade (1) to move in a spiral along longitudinal axis (41) of the housing; the pitch setting mechanism (4) comprises a blade weight compensation mechanism (7), which fully or partially counteracts the imbalance effect of the blade weight on the longitudinal position of the blade relative to the blade housing relative to other blades, and the blade weight compensation mechanism (7) comprises: (a) a guide element (8) located around the axis (40) of the sleeve; and (b) a part (9) coupled with the guide element, wherein the movement of said part (9) coupled with the guide element is limited to movement around the guide element (8). 1 - blade, 2. The pitch control system (100) of claim 1, wherein: (a) the guide (5) is located on the side surface (44, 45) of the housing (2) for the blade; and (b) mating with the guide part (6) is located on the side surface (46, 47) of the butt (16) of the blade. 2 - housing for the blade, (2) List of characters. 3. The pitch control system (100) of claim 1, wherein: (a) the guide (5) is located on the side surface (46, 47) of the butt (16) of the blade; and (b) mating with the guide part (6) is located on the side surface (44, 45) of the housing (2) for the blade. 3 - elastic element, 4. The pitch control system (100) of claim 1, wherein: (a) the inner diameter of the butt (16) of the blade is larger than the outer diameter of its corresponding body (2); and (b) the butt (16) of the blade is slidable over its corresponding housing (2) for the blade. 4 - step setting mechanism, 5. The pitch control system (100) of claim 1, wherein the housing (2) for the blade is wholly or partly contained within the sleeve (12). 5 - guide, 6. The pitch control system (100) of claim 5, wherein the blade body (2) protrudes radially outward from the outer side surface of the hub (12). 6 - interfaced with the guide part, 7. The pitch control system (100) of claim 1, wherein the guide element (8) has a non-circular cross-section or center that is vertically offset from the hub axis (40). 7 - blade weight compensation mechanism, 8. The pitch control system (100) according to claim 1, in which the elastic element (3) is a coil spring, which: (a) aligned with the longitudinal axis (41) of the housing; (b) passes through the sleeve (12), the side wall (27) and the housing (2) for the blade; (c) connected at one end to the butt (16) of the blade and at its other end to the blade weight compensation mechanism (7). 8 - guide element, 9. The pitch control system (100) of claim 1, wherein: (a) the guide element (8) has a cylindrical shape; and (b) the part (9) associated with the guide element is cylindrical and concentric with the guide element (8), wherein the part (9) associated with the guide element is rotatable around the guide element (8). 9 - part associated with the guide element, 10. The pitch control system (100) of claim 1, also comprising: (a) a rod (19) having a first end and a second end; (b) a lever (24) having a first end and a second end, wherein the first end of the rod (19) is inside the butt (16) of the blade or housing (2) for the blade and passes through the hole in the side wall of the sleeve (12), the second end rod (19) is pivotally connected to the first end of the lever (24), the second end of which is pivotally connected to the part (9) conjugated with the guide element. 10 - shaft, 11. The pitch control system (100) according to claim 1, in which the elastic element (3) is a torsion spring (48) that surrounds the inner part or the outer part of the guide element (8) and is connected to the part (9) associated with the guide element . 11 - holding part, 12 - bushing, 13 - fairing, 14 - engine, 15 - engine cover, 16 - butt of the blade, 17 - normal bearing, 18 - binormal bearing, 19 - rod, 20 - bearing, 21 - limiter, 22 - insert, 23 - connector, 24 - lever, 25 - pin, 26 - back wall, 27 - side wall, 28 - mounting hole, 29 - key, 30 - key groove, 31 - connecting parts, 40 - hub axle, 41 - longitudinal axis of the housing for the blade, 42 - imaginary plane, 43 - spiral path segment, 44 - side inner surface of the housing for the blade, 45 - side outer surface of the housing for the blade, 46 - lateral inner surface of the butt of the blade, 47 - lateral outer surface of the butt of the blade, 48 - torsion spring, 49 - the first end of the rod, 50 - the second end of the rod, 51 - the first end of the lever, 52 - the second end of the lever, 53 - step increase section, 54 - step reduction section, 55 - installation section, 100 - step control system. CLAIM 12. The pitch control system (100) of claim 1, wherein: -