RU2751168C1 - Coaxial load-bearing system - Google Patents

Abstract

FIELD: aviation.

SUBSTANCE: invention relates to aviation equipment, namely to structures of load-bearing systems of helicopters. The coaxial load-bearing system comprises a reduction gear (11) with two coaxially located shafts (10; 13) of opposite rotation, whereon heads (15) of main rotors (1; 2) are mounted. The heads consist of a torsion bar (16), a hub (17), adapters (18), units (19) for dynamic balancing of the propeller, and blade drivers (20). Two swash plates (3; 4) movable in the axial direction are kinematically connected with the blade control rods (22). Identical swashplates (3; 4) kinematically independent from each other are installed on sockets (10; 13) with a 180° turn. The heads (15) are attached to the shafts (10; 13) by means of a splined joint (12; 14). Each swashplate (3; 4) comprises a non-rotating ring (21) installed on a spherical slider (28), a rotating ring (23) connected with the non-rotating ring (21) by means of a rolling bearing (24), non-rotating spline-hinges (30) are installed on the non-rotating ring (21), attached to the upper and lower platforms (7; 8) whereon servo drives (27) are installed, connected with the non-rotating ring (21).

EFFECT: increased reliability of the coaxial load-bearing system of a helicopter, reduced total number of units and parts are achieved.

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Description

The invention relates to aeronautical engineering, namely to a helicopter carrier system with coaxially located two counter-rotating main rotors.

A well-known twin-screw bearing system with a mirrored swashplate arrangement (RU 2383470, 03/10/2010), containing a gearbox with two coaxial hollow shafts rotating in opposite directions, on which rotor hubs are fixed, a chain of coordinated control of the total, differential and cyclic pitch of each of the carriers screws, including two swashplate. In this case, a hollow stationary column is introduced inside the rotating shaft of the upper screw, made with the possibility of axial movement downward relative to the hub of the drive gear of the reducer. The control rods for the cyclic pitch run inside the column, the upper screw swashplate is installed in the upper part of the column, and its sliding ring is connected by a rod with an additional sliding ring installed in the lower part of the column. The control elements of the upper screw are installed on the shaft and on the column so that the downward movement of the shaft occurs without dismantling the control system or gearbox, and bringing it into working condition without additional adjustment of the control system.

Also known is a helicopter carrier system (RU 2412081, 02/20/2011) with coaxially positioned counter-rotating rotors, containing a gearbox with two counter-rotating shafts, on which rotor hubs are mounted, two connected by rods to each other and movable in the axial direction of the swashplate, kinematically connected with blade leads and summing lever control system for total and differential pitch. The rotor hubs are made with torsion-mounted blades and spaced horizontal hinges in the form of ball bearings. The summing lever system includes two pairs of two-arm levers and a slider. The first pair of levers is located under the lower swashplate, the second pair of levers and the slider are located at the bottom of the gearbox housing. One of the levers of each pair is fixed to the gearbox housing, the other is pivotally suspended from it. The slider is mounted in the cylindrical cavity of the gearbox, the longitudinal axis of which is aligned with the axis of the upper rotor shaft. The suspended arms of each pair are connected to the lower swashplate and slider, respectively. By means of rods and rockers, the suspended levers are connected to the differential pitch control, and the levers, fixed to the gearbox housing, are connected to the total pitch control. The upper rotor is controlled by means of two-arm rockers mounted on the upper rotor shaft movably along its axis and kinematically connected with the slider, the upper swashplate and the blade drives. In this carrier system, the control of the upper and lower rotor is mechanically coupled.

The disadvantage of these technical solutions is the greater number of structural elements, which entails reduced reliability relative to the proposed technical solution, increased weight of the structure as a whole and increased production and maintenance costs. In the case of patent RU 2383470, this is due to the fact that the upper and lower swash plates are kinematically interconnected by means of a complex system of rods and rockers with a large number of moving parts. Also, the location of the control rods inside the hollow stationary column leads to an increase in the diameter of this column and, as a consequence, to an increase in the diameters of the upper and lower rotor shafts, which leads to a decrease in the payload that the helicopter can lift. With regard to the patent RU 2412081, it is worth noting that a slider of a complex design for controlling the upper rotor in a common pitch, as well as a mechanical limitation of the control advance angle.

The aim of the proposed technical solution is to increase the reliability of the helicopter carrying system with pine, including by reducing the total number of parts and assemblies used, reducing the cost of production and maintenance of the helicopter as a whole.

The technical result is achieved by the fact that the swash plates are made the same, which leads to a decrease in the nomenclature of manufactured parts, and simplification of maintenance and adjustment of the supporting system as a whole, which leads to cost savings.

Also, the rejection of the mechanical connection between the swash plates leads to a decrease in the number of rods and rockers and, as a result, to a reduction in the cost of production and maintenance.

Also, in view of the fact that the swash plates are not kinematically connected, the design allows not to constructively introduce the control advance angle into the design, but to set it in digital form and change it in accordance with the flight mode, which leads to a decrease in the complexity and cost of parts and an increase in efficiency. in all flight modes.

Such an implementation of the carrier system makes it possible to simulate various helicopter control systems:

- full control of both screws;

- Cyclic step control only with the lower screw;

- Cyclic pitch control only with the upper screw.

This allows the pros and cons of control systems to be explored on the same carrier system, leading to lower testing costs.

The use of electromechanical servo drives makes it possible to reduce the number of kinematic connections, which leads to a decrease in the number of parts and a reduction in the cost of production and maintenance of the helicopter. It also makes it possible to make a stationary column of a small radius, which leads to a decrease in the diameters of the shafts, and as a consequence, to a decrease in the weight of the gearbox and the supporting system.

The use of control leashes in the design, instead of more complex structural casings, leads to a decrease in the number of parts and simplification of production.

The invention is illustrated by drawings, where:

- in Fig. 1 depicts the proposed coaxial carrier system;

- in Fig. 2 shows the rotor hub;

- in Fig. 3 shows a swashplate.

The coaxial support system consists of an upper rotor 1, a lower rotor 2, an upper rotor swashplate 3, an upper rotor swashplate 4, an upper cup 5, a lower cup 6, an upper platform 7, a lower platform 8, shafts 10, 13 and an inter-shaft support 9 installed to increase the stiffness of the shafts. Shafts 10 and 13 of the gearbox are located coaxially and have opposite rotation. The upper rotor 1 is mounted on the shaft 10 of the gearbox 11 by means of a spline connection 12. The lower rotor 2 is mounted on the shaft 13 of the gearbox 11 by means of a spline connection 14. Each of the rotor 1 and 2 consists of a sleeve 15, which includes a torsion bar 16, a hub 17 , adapters 18, nodes for dynamic balancing of the propeller 19, leads 20 and rotor blades. The non-rotating ring 21 of the swash plate 3 and 4 is installed on the glass 5 and 6, respectively. By means of rods 22, the rotating ring 23 of the swashplate 3 and 4 is attached to the vane drivers 20. The non-rotating swashplate 21 is connected to the rotating ring 23 by means of a rolling bearing 24. The non-rotating swashplate 21 is connected by means of rods 25 to rockers 26 with servo drives 27. The non-rotating ring 21 is mounted on a spherical slide 28 and has the ability to tilt relative to it. The spherical slider 28 has the ability to move along the glasses 5, 6. Also on the rotating ring there is a slot-hinge 29, which in turn is attached to the bushings of the screws 15. On the non-rotating ring 21 of the swashplate, a non-rotating slot-joint 30 is also installed, which in turn is attached to the disk of servos 7 and 8. The upper and lower swash plates are made the same. The upper swashplate is rotated 180 degrees relative to the horizontal plane relative to the lower swashplate.

The helicopter is controlled in the vertical direction by changing the total pitch on the upper and lower propellers, control in the longitudinal-transverse direction is carried out by changing the cyclic pitch on the upper and lower rotor, along the course - by controlling the differential pitch of the propellers.

The control of the common pitch of the screws is carried out due to the synchronous supply of an electrical signal to the input of all servo drives 27 and, as a consequence, a synchronous change in the angle of installation of the rockers 26 of the servos 27 by the same angle on the upper swashplate 3 and the lower swashplate 4. Since the rockers 26 servo drives by means of rods 25 are connected to non-rotating rings 21, then non-rotating rings 21 and after it the rotating rings 23 of the swashplate move in the direction of the axis of the screw shaft 10 relative to the bushings 15, due to this movement of the rod 22 change the angle of installation of all blades, since they are kinematically connected to the rotating ring 23.

Cyclic step control is carried out due to the synchronous supply of an electrical signal to the input of all servos 27, and, as a consequence, synchronous changes in the angles of installation of the rockers 26 of the servos 27, but at such angles to ensure the inclination of the non-rotating ring 21 of the swashplate relative to the spherical slide 28, and after behind it is a rotating ring 23, which, by means of rods 22, cyclically changes the angles of the blades at each revolution.

Differential pitch control is carried out by different changes in the total pitch on the top 1 and bottom 2 rotors.

The AP design allows you to change the design of the rotor (blades, bushings) in wide ranges, without fear of changing the required lead angle, because the swash plates are not kinematically coupled.

Claims (2)

1. Coaxial bearing system containing a gearbox (11) with two coaxially positioned shafts (10; 13) of opposite rotation, on which sleeves (15) of the main screws (1; 2) are mounted, consisting of a torsion bar (16), a hub (17) of adapters (18), knots (19) of dynamic balancing of the propeller, levers (20) of the blades, which has two axially movable swashplate (3; 4), kinematically connected with the rods (22) of the blade control, characterized in that they are installed with a turn on 180 ° relative to the horizontal plane on the glasses (10; 13) the swash plates (3; 4) are identical and kinematically independent of each other, the bushings (15) are attached to the shafts (10; 13) by means of a spline connection (12; 14), while each of the swash plates (3; 4) contains a non-rotating ring (21) mounted on a spherical slider (28), a rotating ring (23) connected to a non-rotating ring (21) by means of a rolling bearing (24), on a non-rotating ring (21) installed non-rotating walkways c-hinges (30) attached to the upper and lower platforms (7; 8), on which the servos (27) are mounted, connected to the non-rotating ring (21) by means of rods (25), rockers (26), and on the rotating ring (24) there is also a slot-hinge (29) attached to the bushings (15 ) of the upper and lower rotors (1; 2), the spherical slider (28) is installed on the glasses (5; 6) with the possibility of free movement along them, and the shafts (10; 13) are additionally interconnected by an inter-shaft support (9). 2. Coaxial bearing system according to claim 1, characterized in that the leashes (20) are made in the form of beams.

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