RU2728945C1 - Helicopter swashplate - Google Patents

Abstract

FIELD: aviation.SUBSTANCE: invention relates to aircraft engineering and can be used in helicopter control system. Main rotor swashplate automatic device comprises rotary plate (6) with blades turn rods (7) connected to drive (10) and installed through bearing on non-rotating external ring of cardan (5), to which there are pivotally connected rods of longitudinal (13) and transverse (14) controls and connected via bearings with inner ring of cardan (4), slider (2). Ear (3) is connected via bearings with lever of common pitch (11) with pivots of longitudinal (8) and transverse (9) controls hingedly fixed on it, each of which is also pivotally connected to tie-rods of longitudinal (13) and transverse (14) controls and to bracket of common pitch lever (12). At that, in swashplate, selection of ratio of arms of rockers a, b, a1, b1 of longitudinal and transverse controls is used, which are related to corresponding sizes of arrangement of fixation axes of said rockers on lever of common pitch c, d, c1, d1 proceeding from conditions a/b = c/d; a1/b1 = c1/d1.EFFECT: enabling elimination of dynamic cross communication in the common pitch channel and reducing the load acting on the actuator in the common pitch channel.1 cl, 6 dwg

Description

The invention relates to the field of aviation technology and can be used in a helicopter control system or in a control system for another vertical take-off vehicle and is aimed at eliminating kinematic and dynamic cross-links in control channels.

Kinematic cross-coupling occurs, for example, when there is an effect of displacement in a common pitch on the deflection angles in a cyclic pitch. The presence of cross-linking leads to the complication of the piloting technique due to the need to perform coordinated actions of the pilot in the channels of lateral and longitudinal control when changing the position of the common step. Dynamic cross-coupling occurs when forces are transferred from one control channel to another control channel, for example, when forces are transferred from cyclic control channels to a common pitch control channel.

Some of the design solutions used on the claimed swashplate coincide with the design solutions used on the helicopter swashplate used on the Mi-8 type helicopters (see, for example, p. 218 "Mi-8MTV Helicopter" by Transport Publishing House, 1995) , namely, the dependence of the movement of the rockers of the longitudinal and transverse controls on the movements of the slide along the guide. Parallelogram mechanisms are usually used to reduce the influence of common step control on cyclic control that inevitably arises with such a dependence. But due to design constraints, it is not possible to ensure complete coincidence of the lengths of opposite elements (sides) of parallelogram mechanisms, which leads to the appearance of a kinematic cross-connection in the control system.

Also known is the design of the swashplate (RF patent 2088479 В64С 27/605, publ. 04/19/1994), in which the common pitch lever is made in the form of a rocker fixed on the gearbox housing, to one end of which the booster thrust is attached, and to the other the inner ring of the cardan , moreover, the longitudinal and transverse control rods are attached to the outer ring of the universal joint. The disadvantage of this scheme is the presence of a kinematic cross-connection in the control of the cyclic step when changing the total step.

A solution is also known, see for example US patent 2009242691 (A1) publ. 10/01/2009, in which the rotating swashplate is controlled via servos connected to a non-rotating swashplate, and the control signals from the controls in the cockpit are converted into servo control movements using electronic control. In such a control system, a decrease in kinematic cross-coupling in control is ensured by choosing the appropriate dependencies (control laws) connecting the controls and servo drives, and changing the magnitude, speed and direction of the servo drives, taking into account the feedback, which consists in controlling the response of the aircraft to the movement of the controls. Thus, in such a model of the control system, the reduction of kinematic cross-links in control is achieved by electronic means that provide a minimum difference between the desired command and the response of the aircraft. Such an electronic control system is required, as a rule, in tiltrotors with rotary screws, in which it is difficult to provide the required control laws using mechanical devices. The swashplate used in US2009242691 is controlled by a common step by moving three servos at once, and to control at least one of the cyclic control channels, it is required to move two servos simultaneously. This swashplate design, commonly referred to as a three-servo swashplate and a ball bearing, requires either an additional mechanical mixing mechanism or electronic systems. The disadvantage of using a mixing mechanism is the increase in weight and dimensions of the control system. The addition of another element to the control system, such as a mixer, reduces overall reliability. The disadvantage of using electronic systems is lower reliability compared to mechanical control systems.

The closest analogue is the swashplate diagram presented in patent EP 3281869, B64C 27/605, publ. 02/14/2018 In one of the variants of the swashplate described in this patent, the drive arm is pivotally mounted on a non-rotating sliding sleeve and is adapted under the action of a control force for axial displacement of the non-rotating sliding sleeve, which is mounted on the shaft. The pivot support is adapted to move the actuator lever, so that the rotary movement of the actuator lever on the pivot support under the action of a control force is translated into a rotary movement, at least one drive lever on a non-rotating sliding sleeve, which is configured to axially displace on the rotor shaft a non-rotating sliding sleeve that is mounted on the rotor shaft. The at least one hinge bearing comprises at least one carrier that is adapted to carry at least one actuator arm, the at least one carrier comprising a fiber-reinforced composite material.

In EP 3,818,869, the cyclic control arms are placed on the common pitch arm, which leads to the possibility of cross-coupling, expressed in the effect of the movement of the collective pitch arm on the deflection of the cyclic control arms. When placing the cyclic control rockers on the common pitch lever, conditions also arise for the transfer of forces from the cyclic control channels to the common pitch control channel.

A technical problem that has not been solved in the known devices, the solution of which is provided by the claimed invention, is to create a swashplate in which there is no influence of the movement in the general step on the tilt of the plate, i.e. to cyclic control, and also ensures that no effort is transferred from the cyclic control channels to the common pitch control channel.

- and is achieved by placing the longitudinal and transverse control rockers on the common pitch lever, while the corresponding shoulder ratios on the longitudinal and transverse control rockers are equal to the corresponding distance ratios determining the location of the pivot axes of these rockers on the common pitch lever.

The technical result consists in eliminating cross-communication when moving in a common step by the value of the tilt angle of the plate, i.e. on cyclic control, as well as in eliminating the transfer of efforts from the cyclic control channels to the common pitch control channel, which is aimed at reducing the load on the pilot, in simplifying the helicopter piloting technique, due to the reduction of the required number of movements by the helicopter controls performed by the pilot, at all flight modes and a decrease in the weight of the structure associated with a decrease in the forces acting in the channel with a common step due to the lack of transfer of forces to the channel of the general step from the forces from the channels by cyclic control.

The technical result is achieved due to the fact that in the swashplate of the main rotor of the helicopter, containing a rotating plate 6 with rods of turning the blades 7, connected to the leash 10 and mounted through a bearing on the non-rotating outer ring of the cardan 5, to which the longitudinal 13 and transverse rods are hinged 14 controls and connected through bearings with the inner ring of the cardan 4, the slider 2 sliding along the guide of the slider 1, the shackle 3 connected through the bearings to the lever of a common pitch 11 with the longitudinal 8 and lateral 9 control rockers hinged on it, each of which is also hingedly connected to the rods of the longitudinal 13 and transverse 14 controls and the lever bracket of the general pitch 12, in accordance with the claimed invention, - in the swashplate, the choice of the ratio of the arms of the rockers "a", "b", "a1", "b1" of the longitudinal and lateral controls is applied, associated with the corresponding dimensions of the location of the axes of fastening of these rockers on the lever total his steps "c", "d", "c1", "d1" based on the following conditions:

, where a and b are the arms of the longitudinal control rocker 8;

c and d - dimensions on the common pitch lever 11, which determine the location of the longitudinal control rocker axis 8;

a 1 and b1 - arms of the lateral control rocker 9;

c1 and d1 dimensions on the common pitch lever 11, defining the location of the axle of the lateral control 9.

Also, in the swashplate, no effort arises on the actuator in the common pitch channel from the action of moments in the channels of transverse and longitudinal controls as a result of balancing the moments on the common pitch lever relative to the axis of the common pitch lever bracket, while the moment М _{A is} balanced by the moment М _B in accordance with relation [8] for the longitudinal control channel, and the moment M _{A1 is} balanced by the moment Мв1 in accordance with the relation [9] for the lateral control channel:

Where

Р _A - force from the moment Мт in longitudinal control (see [5] and Fig. 4), equal to

где R - расстояние от центра кардана до тяги продольного управления;

where R is the distance from the center of the universal joint to the longitudinal control rod;

Мт - moment on the swashplate in the longitudinal control plane;

Рк - resultant from the forces in the cardan bearings from the moment Мт, applied in the cardan shaft center, equal in magnitude and opposite in direction to the force Р _A ;

M _A - the moment about the x-x axis from the force P _A applied in tA;

Мв - moment about the x-x axis from the action of the force Pk applied in the center of the cardan;

- c and d - dimensions on the common pitch lever 11, determining the location of the longitudinal control arm 8.

where P _{A1 is the} force from the moment Мт1 in transverse control, equal to

где R1 - расстояние от центра кардана до тяги поперечного управления;

where R1 is the distance from the center of the universal joint to the lateral control rod;

Мт1 - moment on the swash plate in the plane of transverse control;

Р _К1 - resultant from the forces in the cardan bearings from the moment Мт1, applied in the cardan shaft center, equal in magnitude and opposite in direction to the force Р _А1 ;

M _A1 - moment about the x-x axis from the force P _A1 applied to tA1;

Мв1 - moment about the x-x axis from the action of the force P _K1 applied in the center of the cardan;

- c1 and d1 dimensions on the common pitch lever 11, determining the location of the axle of the lateral control 9

The fulfillment of the relation [1] ensures the absence of cross-coupling in the longitudinal control channel, the fulfillment of the relation [2] ensures the absence of cross-communication in the lateral control channel. This makes it possible to reduce the burden on the pilot due to the simplification of helicopter piloting techniques and to improve flight safety.

The fulfillment of the relations [8] and [9] ensures the absence of dynamic cross-coupling, which reduces the acting loads on the actuator for controlling the common pitch, thereby increasing safety and reducing the weight of the structure.

The design of the swashplate is shown in the images:

fig. 1 - Bottom and side view;

fig. 2 - View from the left, top, from the side of the longitudinal control

fig. 3 - Bottom and side view from the side of the transverse control (the slide guide and the bracket are not shown conventionally);

fig. 4 - Diagram of the swashplate illustrating the absence of cross-kinematic and dynamic links,

fig. 5 - Section in the plane of the universal joint rings;

fig. 6 - A variant of the swashplate diagram with non-parallel axes of fixing the longitudinal and lateral control rockers.

The helicopter swashplate (Fig. 1, 2) consists of a slide guide 1, a slide 2, an earring 3, an internal 4 and an external 5 cardan rings, a plate 6 with rods for turning the blades 7, longitudinal 8 and lateral 9 rockers, a leash 10, a lever common pitch 11, arm bracket of common pitch 12, longitudinal rods 13 and transverse 14 controls.

The swash plate is attached to the gearbox housing by bolting along the flanges of the slide guide 1 and the lever bracket of the general pitch 12. To the longitudinal 8 (point F of Fig. 3) and transverse 9 (point D of Fig. 3) rockers and to the general pitch lever (point E Fig. 3) actuators are attached. Also, a stabilizer control drive can be attached to the common pitch lever (point E1 in Fig. 3). The rods of turning the blades 7 by means of hinges on one side are attached to the levers of turning the blades, and on the other, by means of hinges, they are fixed on the rotating plate of the swash plate 6. The plate of the swashplate 6 is fixed on the outer ring of the cardan by means of the bearing (bearings) 5. The plate of the swashplate 6 is driven in rotation through a leash (slot-hinge) 10, which is attached to the swash plate 6 by means of a spherical bearing. The leash 10 with its bracket is rigidly fixed relative to the main gearbox shaft and the rotor hub by means of a pin, thereby ensuring synchronous rotation of the swashplate 6 and the rotor hub. The outer cardan ring 5 by means of bearings is attached to the inner cardan ring 4 (see Fig. 5), which in turn is attached to the slider 2 by means of bearings. The slider 2 is pivotally attached to the common pitch lever 12 by means of the shackle 3, which in turn is attached through the bearings to the arm of the general pitch 12 lever. The longitudinal 8 and transverse 9 control arms are pivotally attached to the general pitch lever 12. The longitudinal control rod 13 is attached to the longitudinal control rocker 8, the lateral control rod 14 is attached to the lateral control rocker 9. The longitudinal and lateral control rods 13, 14 are also attached by means of hinges to the outer cardan ring. The described design provides the transfer of control actions from non-rotating actuators to the levers of rotation of the blades rotating at the speed of rotation of the main gearbox shaft.

The device works as follows.

The helicopter swash plate is designed to change the magnitude and direction of the resultant aerodynamic forces and moments arising on the main rotor of the helicopter in order to ensure control of the helicopter.

The simultaneous change in the angles of the rotor blades leads to a change in the magnitude of the resultant aerodynamic forces coming to the rotor hub from the blades fixed on it, the so-called common pitch control. Cyclic change in the angles of the rotor blades leads to a change in the direction of the resultant aerodynamic forces and moments on the rotor hub, coming from the blades, the so-called cyclic pitch control in the planes of the longitudinal and transverse controls.

Additionally, the swashplate can drive the stabilizer, which is controlled by connecting the common pitch lever by means of rods (ropes or a combination of rods and ropes) with a rocker on the stabilizer. A possible place for such a connection to the swashplate can be the holes E1 on the common pitch lever 11 (Fig. 3).

The swashplate is installed on the main rotor gearbox, is connected to the actuators that do not rotate relative to the main gearbox axis and to the blades rotation levers rotating relative to the main gearbox axis and transfers, on the one hand, the control movements from the actuators (hydraulic boosters, electric drives, etc.) control systems to the rotor blades turning levers, being a connecting mechanism between non-rotating and rotating parts of the control system, and on the other hand, it receives and transfers the forces from the blade turning levers arising from the hinge moments on the blades, to the actuators and to the main gearbox housing.

Control over the total pitch is provided by turning the lever of the general pitch 11 relative to the hinge of the bracket 12, which leads to the vertical movement of the shackle 3 and the slider 2 fixed to it by means of two bearings. Slider 2, moving relative to the guide slide 1, leads to the vertical movement of the slide fixed on the slide with the help of two bearings of the inner ring of the cardan 4, which in turn leads to the movement of the cardan fixed on the inner ring with the help of two bearings of the outer ring of the cardan 5 (see Fig. 5). The swash plate 6, installed through the bearing (bearings) on the outer ring of the cardan 5, transmits vertical displacements to the rods of turning the blades 7, which leads to a simultaneous (total) change in the angles of the blades.

Cyclic pitch control is provided by turning one of the longitudinal 8 or lateral 9 control rods, leading to vertical movement of the corresponding rods of the longitudinal 13 or transverse 14 controls, which in turn leads to an inclination relative to the slider 2 of the cardan rings 4 and 5 by rotating in bearings relative to the universal joint axes (axes OK and O1K in Fig. 5) and plates with rods of rotation of the blades, fixed through the bearing (bearings) on the outer ring of the cardan. The inclination of the outer cardan ring in the plane of the longitudinal or lateral control (see Fig. 5) leads to the inclination of the swash plate 6 in the corresponding plane. The inclination of the plate 6 leads to the fact that during the rotation of the blades associated with the rods of the rotation of the blades 7 there is a cyclic change in the angles of the blades for each rotation of the rotor.

The inventive design is characterized by a specially selected ratio of the arms of the longitudinal 8 and transverse 9 controls, and the corresponding ratios of the arms on the longitudinal 8 and transverse 9 controls are equal to the corresponding distance ratios that determine the location of the axes of these rockers on the common pitch lever 11, as well as the design solutions of assemblies and parts , operational and ergonomic properties.

The above choice of the ratios [1] and [2] of the longitudinal 8 and lateral 9 control rocking arms (Fig. 3, 4) ensures the absence of kinematic and dynamic cross-links between the control channel of the total and cyclic step, and also provides a significant decrease in the values of friction forces arising along the contact surfaces between the slider 2 and the slide guide 1. The friction force is reduced by fixing the longitudinal 8 and 9 transverse control rockers on the common pitch lever 11, and not on the slide bracket, as for example, for the swashplate circuit with a parallelogram reduction mechanism cross-coupling values (see, for example, page 218 "Mi-8MTV Helicopter" published by "Transport" 1995). The effect of reducing the magnitude of the friction force (the magnitude of the friction force is reduced by more than 2 times) is achieved by reducing the magnitudes of the forces coming to the slide guide from the moments on the swashplate, in the considered scheme, in comparison with the swashplate with a parallelogram mechanism for reducing the value of the cross communication. The decrease in the values of the forces coming to the slide guide from the moment on the swashplate is due to the fact that part of this moment is directly closed through the common pitch lever 11 and the bracket of the common pitch lever 12 to the main gearbox housing.

To exclude the kinematic and dynamic cross-links between the movement along a common step and cyclic control in the claimed solution of the swashplate, the choice of the ratio of the arms of the rockers "a", "b", "a1", "b1" of the longitudinal 8 and lateral 9 controls (Fig. 3 , 4), associated with the corresponding dimensions of the location of the axes of fastening of these rockers on the lever of a common pitch "c", "d", "c1", "d1" based on the following conditions:

, where a and b are the arms of the longitudinal control rocker 8 (Figs. 3, 4);

c and d - dimensions on the common pitch lever 11, which determine the location of the longitudinal control rocker axis 8;

a 1 and b1 - arms of the lateral control rocker 9;

c1 and d1 dimensions on the common pitch lever 11, defining the location of the axle of the lateral control 9.

As noted above, the fulfillment of the relation [1] ensures the absence of cross-coupling in the longitudinal control channel, the fulfillment of the relation [2] ensures the absence of cross-communication in the lateral control channel.

Indeed, with fixed points of attachment of the actuators of the control (point D and point F of Fig. 3) and the movement of the actuator associated with the common pitch lever in point E, the slider in point B and point B1 will move a certain distance Δ = ΔtB = ΔtB1 (Fig. 4). The longitudinal control rocker 8 along the fixing axis at point C moves by ΔC. Taking into account the relation [1], we formulate the relation [3]:

, where ΔС is the movement of the longitudinal control rocker axis 8 (Figs. 3, 4),

Δ - displacement of point B and B1 of the common pitch lever (Figs. 3, 4).

Accordingly, the movement in point A of the longitudinal control rocker 8 (with point F fixed) will be:

, where ΔA is the movement of the longitudinal control rocker 8 (Fig. 3, 4).

Taking into account the relation [4], displacements in point A are equal to displacements in point V. Similar reasoning leads to the fact that displacements in point A1 are equal to displacements in point B1.

Thus, when relations [1] and [2] are fulfilled, any movement of the common pitch lever, leading to the movement of point B and point B1, leads to exactly the same displacements in point A and point A1 on the longitudinal 8 and transverse rockers 9 departments, i.e. the relation [4а] is fulfilled:

Considering that the rockers of the longitudinal 8 and transverse 9 controls are connected (Fig. 1, 2) through the rods 13, 14 with the outer cardan ring 5, and the common pitch lever 11 by means of the shackle 3, the slider 2 and the inner cardan ring 4 is also connected with the cardan ring outer 5, then the fulfillment of equality [1] leads to equality [4a], the fulfillment of which ensures the plane-parallel movement of the outer cardan ring 5 and the swash plate 6. This ensures the absence of the influence of the movement along the general step on the cyclic control in the longitudinal and transverse control channels, those. the absence of kinematic cross-connection in the control channels is ensured.

The absence of kinematic cross-connection in the control channels ensures the normal functioning of the helicopter control system, significantly reduces the workload on the pilot, simplifies the helicopter piloting technique, reducing the required number of movements of the helicopter controls performed by the pilot in all flight modes and increases flight safety.

The absence of dynamic cross-connection is to exclude the influence of efforts in one of the control channels on the forces arising in the other control channel. In this design, the condition for the absence of dynamic cross-coupling is the absence of the influence of efforts in cyclic control (in the channels of longitudinal and transverse control) on the forces coming to the actuator in the control channel of the common pitch, and is also ensured by fulfilling the relationship [1] and [2] The absence of cross-dynamic communication significantly, more than 2 times, reduces the loads acting on the actuator in the common-pitch channel, which leads to a decrease in the weight of the structure and an increase in reliability.

When flying on a rotating plate 6, a moment Mt arises from the efforts on the rods of turning the blades (these forces arise from the hinge moments on the blades), which in turn is transmitted through the bearing (bearings) of the swashplate to the non-rotating structure of the swashplate. In the general case, the moment on the swash plate 6 leads to the occurrence of forces in both longitudinal and transverse controls. Considering that these moments act in mutually perpendicular planes, then the action of these moments can be considered independently of each other. Consider the action of the moment Мт, for example, in the longitudinal control channel, acting in the longitudinal control plane (see Fig. 5). The moment Мт on the plate 6 of the swashplate through the bearing (bearings) acts on the outer ring of the universal joint 5. The action of the specified moment Мт in the design of the swashplate results in a pair of forces Р _А and Р _К. (see Fig. 4). The indicated forces are equal in magnitude and opposite to each other in direction. One of the forces (P _A ) is applied to the longitudinal control rod 13 (Fig. 5) in the T.O. The second force (P _K ) is the resultant (from the forces on the cardan bearings) applied in the center of the cardan at point K at a distance R from point O (see Figs 4, 5). Thus:

, where P _A is the force applied in the longitudinal control rod 13 (Fig. 4, 5),

R _K - resultant from forces in the cardan bearings, applied in the center of the cardan (Fig. 4, 5),

R is the distance from the center of the universal joint (T. K in Fig. 5) to the longitudinal control rod (T. O in Fig. 5).

MT is the moment on the swash plate (6) (see Fig. 5).

Consider the action of these forces on the common pitch lever.

Let us assume that the direction of the moment on the plate MT (Fig. 5) is such that the longitudinal control rod 13 is stretched, i.e. the force P _{A is} directed vertically upward with respect to the plane of the gimbal, respectively, in the center of the gimbal, the force P _{K is} directed vertically downward.

The force P _K , acting sequentially through the bearings of the inner cardan ring 4, then through the slider 2 and the shackle 3, will cause two equal forces P _B in the bearings of the shackle 3 to the common pitch lever (in point B and point B1 in Fig. 3) and Р _В1 determined by the relation [5a]:

- Р _В and Р _В1 - forces at points T. B and T. B1 (see Fig. 3) of the general pitch lever 11 at the point of attachment of the earring 3;

The forces Р _В and Р _В1 will lead to the occurrence of the moment Мв on the lever of the common pitch 11 relative to the swinging axis of the lever of the common pitch (the x-x axis coincides with the axis of the arm of the lever ОШ in Fig. 3). In this case, the value of the moment Мв is determined taking into account [5а] by the relation [6]:

where

- c and d - dimensions on the common pitch lever 11, determining the location of the longitudinal control arm 8

- c1 and d1 dimensions on the common pitch lever 11, which determine the location of the axle of the lateral control 9;

- Мв - the moment on the lever of the general pitch 11 relative to the x-x axis from the action of the force P _K (see Fig. 4);

In relation [6] it is taken into account that point B and point B1 are located on the same axis parallel to the x-x axis and, therefore, c + d = c1 + d1.

From the force P _A applied to the longitudinal control rocker in point A, with the fixed point F (the point of attachment of the actuator to the longitudinal control rocker in Figs 3, 4) on the common pitch lever relative to the x-x axis (see Figs 3, 4) arise torque M _A, which is defined by the relation: [7]

, where M _A is the moment about the x-x axis from the force P _A applied in tA;

- a and b - longitudinal control rocker arms 8;

- c and d - dimensions on the common pitch lever 11, which determine the location of the longitudinal control rocker axis 8;

- P _F - force at point F (see Fig. 4), at the point of attachment of the actuator to the longitudinal control rocker 8;

- Р _С - total (from forces Р _А and Р _F ) force at point С (see Fig. 4) of attachment of the longitudinal control rocker axis 8 to the general pitch lever 11.

Taking into account the ratios [5], [6], [7], we find that the moments M _A and M _B are equal and oppositely directed, that is, their sum about the x-x axis (the axis of the arm of the common pitch lever, see Fig. 3) will be zero [8]:

where Р _A - force from the moment Мт in longitudinal control (see [5] and Fig. 4);

Рк - resultant from the forces in the cardan bearings from the moment Мт, applied in the cardan shaft center (see [5] and Fig. 4, 5);

M _A - moment about the x-x axis from the force P _A applied in tA;

Мв - moment about the x-x axis from the action of the force Pk applied in the center of the cardan;

- c and d - dimensions on the common pitch lever 11, determining the location of the longitudinal control arm 8.

Similar reasoning for the action of the moment on the plate of the swashplate Мт1, acting in the plane of transverse control (see Fig. 5), leads to the fulfillment of the condition of the relation [9]:

where P _{А1 is the} force from the moment Мт1 in transverse control, equal to

где R1 - расстояние от центра кардана до тяги поперечного управления;

where R1 is the distance from the center of the universal joint to the lateral control rod;

Мт1 - moment on the swash plate in the plane of transverse control;

Р _К1 - resultant from the forces in the cardan bearings from the moment Мт1, applied in the cardan shaft center, equal in magnitude and opposite in direction to the force P _А1 ;

M _A1 - moment about the x-x axis from the force P _A1 applied to tA1;

Мв1 - moment about the x-x axis from the action of the force P _K1 applied in the center of the cardan;

- c1 and d1 dimensions on the common pitch lever 11, defining the location of the axle of the lateral control 9 (see Fig. 3);

Note: Moments M _A1 , Mv1 and forces P _A1 , P _{K1 are} not shown in Fig. 4.

Due to the fulfillment of the relations [1] and [2], the fulfillment of the relations [8], [9] is ensured, i.e. the moments Мв, Мв1 relative to the bracket axis of the common pitch (axis x-x) are balanced by the corresponding moments М _А , М _А1 , which leads to a lack of reaction at the point of attachment of the actuator in the control channel of the common pitch (i.e., Figs. 3, 4). Thus, the absence of dynamic cross-coupling in the common pitch channel from the action of the moments Мт, Мт1 in the corresponding planes of the longitudinal and transverse controls (see Fig. 5) on the force in the actuator in the common step control channel is ensured.

FIG. 6 shows a variant of the swashplate diagram with the arrangement of the axes of the longitudinal (C-axis) and transverse (C1-axis) controls, on which these axes are not parallel to the swing axis of the common pitch lever (x-x), in contrast to the variant of Fig. 3, in which the axes C and C1 are parallel to the x-x axis.

For the presented swashplate diagram, working design documentation was developed, prototypes were made, and tests were carried out.

Claims (29)

1. The swashplate of the main rotor of the helicopter, containing a rotating plate (6) with rods for turning the blades (7), connected to a leash (10) and installed through a bearing on a non-rotating outer ring of the cardan (5), to which the longitudinal rods (13) are hinged and transverse (14) controls and connected through bearings with the inner ring of the cardan (4), which in turn is connected with the slide (2) sliding along the slide (1) guide, while the slide (2) is connected to the shackle (3), connected through bearings with a common pitch lever (11) with longitudinal (8) and transverse (9) control rockers pivotally mounted on it, each of which is also hingedly connected to the longitudinal (13) and transverse (14) control rods, while the common the pitch (11) is fixed to the bracket (12) of the collective pitch lever, characterized in that - in the swashplate, the choice of the ratio of the arms of the rockers "a", "b", "a1", "b1" of the longitudinal and transverse controls, associated with the corresponding dimensions of the location of the axes of fixing these rockers on the lever of the common pitch "c", "d" "C1", "d1" based on the following relationships [1] and [2]:

where a and b are the arms of the longitudinal control 8, c and d - dimensions on the lever of a common pitch 11, which determine the location of the longitudinal control rocker axis 8, a1 and b1 - lateral control rocker arms 9, c1 and d1 dimensions on the common pitch lever 11, defining the location of the axle of the lateral control 9. 2. The swashplate according to claim 1, characterized in that there is no effort on the actuator in the common pitch channel from the action of moments in the channels of the transverse and longitudinal controls due to the balancing of the moments on the common pitch lever relative to the axis of the common pitch lever bracket, while the moment M _{A is} balanced by the moment Мв in accordance with the relationship [8] for the longitudinal control channel, and the moment M _{А1 is} balanced by the moment Мв1 in accordance with the relationship [9] for the transverse control channel:

where Р _А - force from the moment Мт in longitudinal control, equal to

, where R is the distance from the center of the universal joint to the longitudinal control rod, MT is the moment on the swashplate in the longitudinal control plane, Рк - resultant from the forces in the cardan bearings from the moment Мт, applied in the cardan shaft center, equal in magnitude and opposite in direction to the force Р _А , M _A is the moment about the x-x axis from the force P _A applied in tA, Мв - moment about the x-x axis from the action of the force Pk applied in the center of the cardan, c and d - dimensions on the lever of a common pitch 11, which determine the location of the longitudinal control rocker axis 8, wherein

where P _A1 is the force from the moment Мт1 in transverse control, equal

, where R1 is the distance from the center of the universal joint to the lateral control rod, Мт1 - moment on the swashplate in the plane of transverse control, Р _К1 - resultant from the forces in the cardan bearings from the moment Мт1, applied in the cardan shaft center, equal in magnitude and opposite in direction to the force Р _А1 , M _A1 is the moment about the x-x axis from the force P _A1 applied to tA1, Мв1 - the moment about the x-x axis from the action of the force P _K1 applied in the center of the cardan, c1 and d1 dimensions on the common pitch lever 11, defining the location of the axle of the lateral control 9.

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