Helicopter rotor system

Abstract

According to the helicopter rotor system, an annular cabin is arranged in an inner cavity of an annular shell, a main rotor structure is arranged in the outer center space through a main speed reducer supporting frame, a tail rotor cabin is formed at the rear end through a tail rotor shell, and a tail rotor is arranged in the tail rotor cabin; the engine is located at the rear part of the annular cabin, backwards outputs power to the tail rotor through a power shaft and forwards outputs power to the main speed reducer through a transmission shaft, and the main speed reducer transmits the decelerated power to the main propeller hub and the main blades through a main rotor shaft; the small pull rod is hinged to an outer edge fork of the moving ring through a ball bearing at the lower end of the small pull rod and is hinged to a transverse shaft at the outer end of the main paddle through a ball bearing at the upper end of the small pull rod; the multiple steering engines are evenly distributed on the same horizontal plane and perpendicularly installed on the main speed reducer supporting frame. According to the invention, a non-open type, supported and limited wingtip design is adopted, so that the wingtip linear velocity of the main rotor of the helicopter can easily break through the sound velocity without generating strong flutter, and a new scheme is provided for double improvement of the speed and the load of the helicopter.

Description

Technical Field

[0001] The invention belongs to the field of aviation technology, and in particular relates to a helicopter rotor system. Background Art

[0002] The technical condition that the wingtip linear speed of a helicopter's main rotor should not exceed the speed of sound has largely limited the increase in helicopter speed. The main reason why the wingtip linear speed of a helicopter's main rotor should not exceed the speed of sound is that the wingtip is open, unsupported, and has no limit. Once the wingtip linear speed approaches or exceeds the speed of sound, strong flutter will occur, affecting the flight quality and causing fatigue to the blade structure. After the flutter reaches a certain degree and for a certain period of time, it will cause a risk of damage to the aircraft.

[0003] At present, the improvement of helicopter speed is mainly achieved in three directions: first, using tail thrust mode; second, hard hub mode; third, using tilting mode. However, these three directions are still carried out under the technical condition that the linear speed of the rotor wing tip does not exceed the speed of sound. The speed improvement of helicopter is limited, and some load will be sacrificed when the speed is increased. Summary of the invention

[0004] In order to solve the problem of increasing the speed of helicopters in the prior art, the present invention provides a helicopter rotor system with a special structure, which adopts a non-open, supported, and limited wingtip design, so that the linear speed of the helicopter main rotor wingtip can easily exceed the speed of sound without strong flutter, providing a new solution for increasing both the speed and load of the helicopter. The technical solution is as follows:

[0005] In a first aspect, a helicopter rotor system is provided, including: an annular cabin 1, an annular housing 2, a torque arm 4, a main rotor blade 6, a main rotor hub 7, a main rotor shaft 8, a large ball hinge core 9, a large ball hinge ring 10, a tail rotor housing 11, a small pull rod 12, a tail rotor cabin 13, a tail rotor 14, a power shaft 15, an engine 16, a transmission shaft 17, a main reducer support frame 18, a dynamic ring 19, a main reducer 20, a fixed ring 21, an anti-torsion arm 22, and a plurality of steering gears 23;

[0006] The annular housing 2 is the support structure of the entire device. The inner cavity of the annular housing 2 is provided with an annular cabin 1. The main rotor structure is arranged in the outer central space through the main reducer support frame 18. The rear end is formed with a tail rotor cabin 13 through the tail rotor housing 11. The tail rotor cabin 13 is provided with a tail rotor 14.

[0007] The main reducer 20 is fixed at the center of the main reducer support frame 18, the upper end of the main reducer 20 extends out of the main rotor shaft 8, the upper end of the main rotor shaft 8 is connected to the main propeller hub 7, and the inner end of the main blade 6 is hinged to the outer edge of the main propeller hub 7;

[0008] The engine 16 is arranged at the rear of the annular cabin 1. The engine 16 outputs power to the tail rotor 14 backward through the power shaft 15. The engine 16 outputs power to the main reducer 20 forward through the transmission shaft 17. The main reducer 20 transmits the decelerated power to the main rotor hub 7 and the main rotor blades 6 through the main rotor shaft 8.

[0009] A large ball joint core 9 is provided between the main reducer 20 and the main propeller hub 7;

[0010] The large ball hinge ring 10 is fixedly connected to the fixed ring 21, and the fixed ring 21 is hinged to the movable ring 19; the movable ring 19 and the fixed ring 21 can only rotate relative to each other, and the other dimensions are limited by the structure between the movable ring 19 and the fixed ring 21. Except for the relative rotation, the other movements of the movable ring 19 and the fixed ring 21 keep following each other;

[0011] The outer end of the torque arm 4 is hinged on the outer edge fork of the dynamic ring 19, and the inner end of the torque arm 4 is clamped on the main rotor shaft 8. Its main function is to completely transmit the rotational motion of the main rotor shaft 8 to the dynamic ring 19, so that the dynamic ring 19 maintains the same relative position and rotation speed with the main rotor shaft 8, and does not hinder the dynamic ring 19 from moving up and down and rotating around the large ball joint core 9;

[0012] The outer end of the anti-twist arm 22 is hinged on the outer edge fork of the stationary ring 21, and the inner end of the anti-twist arm 22 is fixed to the housing of the main reducer 20. Its main function is to prevent the stationary ring 21 from rotating and prevent the stationary ring 21 from being driven by the passive ring 19, while not hindering the up and down movement of the stationary ring 21 and the rotation around the large ball joint core 9;

[0013] The small pull rod 12 is hinged on the outer edge fork of the moving ring 19 through the ball bearing at its lower end, and is hinged on the outer end transverse axis of the main blade 6 through the ball bearing at its upper end; the inner end transverse axis of the main blade 6 is arranged at the leading edge of the blade, and the outer end transverse axis of the main blade 6 is arranged at the trailing edge of the blade. There is a force arm between the inner and outer end transverse axes of the main blade 6. When the small pull rod 12 pushes and pulls the outer end transverse axis of the main blade 6 to move up and down, the elastic ball bearing connected to the inner end transverse axis of the main blade 6 deflects, and the angle of attack of the main blade 6 changes, thereby realizing the pitch change of the main blade 6.

[0014] A plurality of steering gears 23 are evenly distributed on the same horizontal plane and vertically mounted on the main reducer support frame 18. The actuator cylinder of the steering gear 23 is hinged on the outer edge fork of the fixed ring 21 through the ball bearing at its upper end.

[0015] The annular cabin 1, the annular shell 2, the main rotor hub 7, the main rotor shaft 8, the large ball joint core 9, the large ball joint ring 10, the dynamic ring 19, the main reducer 20, and the stationary ring 21 are coaxially arranged.

[0016] Optionally,

[0017] The outer end of the torque arm 4 is hinged to the outer edge fork of the moving ring 19 through a ball bearing;

[0018] The outer end of the anti-twist arm 22 is hinged on the outer edge fork of the fixed ring 21 through a ball bearing.

[0019] The large ball hinge ring 10 is fixedly connected to the fixed ring 21 through the tilter support rod 5, and the fixed ring 21 is hinged to the movable ring 19 through the large bearing 3.

[0020] Among them, the large ball joint core 9 is a structure in which a hollow ball is fixedly sleeved on the outside of a hollow column. The hollow column structure of the large ball joint core 9 is sleeved on the main rotor shaft 8 and can slide up and down along the main rotor shaft 8; the hollow ball structure of the large ball joint core 9 is wrapped in the large ball joint ring 10, forming a spherical gap fit with the large ball joint ring 10. The large ball joint ring 10 can rotate around the hollow ball structure of the large ball joint core 9, and can also push the large ball joint core 9 to slide up and down along the main rotor shaft 8.

[0021] Among them, the small pull rod 12 is a two-force rod structure, with ball bearings at both ends and a solid rod in the middle, which needs to bear both tension and pressure.

[0022] Among them, the main blade 6 is composed of inner and outer end transverse axes and a middle airfoil section; the inner end transverse axis of the main blade 6 is hinged to the outer edge of the main hub 7 through an elastic ball bearing, and the outer end transverse axis of the main blade 6 is hinged to the upper end of the small pull rod 12 through an elastic ball bearing.

[0023] Among them, there are 3 steering gears 23.

[0024] When the actuators of the three servos 23 are synchronously extended and retracted to the same length, each small pull rod 12 pushes and pulls the corresponding main blade 6 to change the pitch in the same way, thereby achieving a change in the total pitch, and the lift of the main rotor increases or decreases evenly, so that the helicopter achieves an ascending or descending movement.

[0025] in,

[0026] When the actuators of the three servos 23 are extended and retracted to different lengths, each small pull rod 12 pushes and pulls the corresponding main blade 6 to change the pitch differently, thereby achieving a periodic change in the pitch. The lift of the main rotor increases or decreases on the corresponding side, and the helicopter achieves pitch and roll posture movements.

[0027] The beneficial effects of the present invention are at least:

[0028] (1) The present invention changes the pitch variation of the traditional helicopter main rotor blades from the blade root margin to the blade tip margin, thereby adding constraints to the main rotor blade tip. The non-open, supported, and limited wingtip design is adopted, so that the linear speed of the helicopter main rotor wingtip can easily exceed the speed of sound without causing strong flutter, thereby providing a new solution for increasing both helicopter speed and load.

[0029] (2) The present invention adopts an annular cabin structure design, which not only adapts to the new main rotor structure design, but also forms a new configuration of the helicopter's internal space structure, greatly increasing the helicopter's internal space.

[0030] (3) The present invention complies with the general logic and principles of helicopter structural design, control and aerodynamics, and is scientific and feasible. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the present invention. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below through specific implementation modes and drawings.

[0033] The present invention provides a helicopter rotor system, see Figure 1 , including: an annular cabin 1, an annular shell 2, a large bearing 3, a torque arm 4, a tilter strut 5, a main blade 6, a main hub 7, a main rotor shaft 8, a large ball hinge core 9, a large ball hinge ring 10, a tail rotor shell 11, a small pull rod 12, a tail rotor cabin 13, a tail rotor 14, a power shaft 15, an engine 16, a transmission shaft 17, a main reducer support frame 18, a dynamic ring 19, a main reducer 20, a fixed ring 21, an anti-torsion arm 22, and a steering gear 23.

[0034] The annular shell 2 is the support structure of the entire device. The internal cavity of the annular shell 2 is the annular cabin 1, which can be used as a cockpit, passenger and cargo cabin, engine cabin, and equipment cabin. The main rotor structure is arranged in the central space outside the annular shell 2 through the main reducer support frame 18, and the tail rotor cabin 13 is formed at the rear end of the annular shell 2 through the tail rotor shell 11, and the tail rotor 14 is arranged in the tail rotor cabin 13.

[0035] The engine 16 is arranged at the rear of the annular cabin 1. The engine 16 outputs power backward to the tail rotor 14 through the power shaft 15, and the engine 16 outputs power forward to the main reducer 20 through the transmission shaft 17. The main reducer 20 transmits the decelerated power to the main hub 7 and the main blades 6 through the main rotor shaft 8.

[0036] The main reducer 20 is fixed at the center of the main reducer support frame 18, the upper end of the main reducer 20 extends out of the main rotor shaft 8, the upper end of the main rotor shaft 8 is connected to the main hub 7, and the inner end transverse axis of the main blade 6 is hinged to the outer edge of the main hub 7 through an elastic ball bearing.

[0037] A large ball joint core 9 is arranged between the main reducer 20 and the main hub 7. The large ball joint core 9 is a structure in which a hollow ball is fixedly sleeved on the outside of a hollow column. The hollow column structure of the large ball joint core 9 is sleeved on the main rotor shaft 8 and can slide up and down along the main rotor shaft 8. The hollow ball structure of the large ball joint core 9 is wrapped in the large ball joint ring 10, forming a spherical clearance fit with the large ball joint ring 10. The large ball joint ring 10 can rotate around the hollow ball structure of the large ball joint core 9, and can also push the large ball joint core 9 to slide up and down along the main rotor shaft 8.

[0038] The annular cabin 1, the annular shell 2, the large bearing 3, the main rotor hub 7, the main rotor shaft 8, the large ball hinge core 9, the large ball hinge ring 10, the dynamic ring 19, the main reducer 20, and the stationary ring 21 are all coaxial.

[0039] The large ball hinge ring 10 is fixedly connected to the fixed ring 21 through the tilter support rod 5, and the fixed ring 21 is hinged to the movable ring 19 through the large bearing 3. The movable ring 19 and the fixed ring 21 can only rotate relative to each other, and the other dimensions are limited by the structure between the movable ring 19 and the fixed ring 21. Except for the relative rotation, the other movements of the movable ring 19 and the fixed ring 21 keep following each other.

[0040] The outer end of the torque arm 4 is hinged on the outer edge fork of the dynamic ring 19 through a ball bearing, and the inner end of the torque arm 4 is clamped on the main rotor shaft 8. Its main function is to completely transmit the rotational motion of the main rotor shaft 8 to the dynamic ring 19, so that the dynamic ring 19 maintains the same relative position and rotation speed with the main rotor shaft 8, and at the same time does not hinder the up and down movement of the dynamic ring 19 and the rotation around the large ball hinge core 9.

[0041] The outer end of the anti-torsion arm 22 is hinged on the outer edge fork of the stationary ring 21 through a ball bearing, and the inner end of the anti-torsion arm 22 is fixedly connected to the housing of the main reducer 20. Its main function is to hold the stationary ring 21 to prevent it from rotating and prevent the stationary ring 21 from being rotated by the passive ring 19, while not hindering the up and down movement of the stationary ring 21 and the rotation around the large ball hinge core 9.

[0042] The pull rod 12 is hinged to the outer edge of the moving ring 19 through the ball bearing at its lower end, and is hinged to the outer end transverse axis of the main blade 6 through the ball bearing at its upper end. The inner end transverse axis of the main blade 6 is arranged at the leading edge of the blade, and the outer end transverse axis of the main blade 6 is arranged at the trailing edge of the blade. Therefore, there is a force arm between the inner and outer end transverse axes of the main blade 6. When the small pull rod 12 pushes and pulls the outer end transverse axis of the main blade 6 to move up and down, the elastic ball bearing connected to the inner end transverse axis of the main blade 6 deflects, and the angle of attack of the main blade 6 changes, that is, the pitch change of the main blade 6 is achieved.

[0043] In one embodiment, three servos 23 are evenly distributed on the same horizontal plane and vertically mounted on the main reducer support frame 18. The actuator cylinder of the servo 23 is hinged on the outer edge fork of the fixed ring 21 through the ball bearing at its upper end. When the actuator cylinders of the three servos 23 are synchronously extended and retracted to the same length, each small pull rod 12 pushes and pulls the corresponding main blade 6 to change the pitch in the same way, that is, the total pitch is changed, the lift of the main rotor is evenly increased or decreased, and the helicopter can achieve an ascending or descending movement.

[0044] When the actuators of the three servos 23 are extended and retracted to different lengths, each small pull rod 12 pushes and pulls the corresponding main blade 6 to change the pitch to a different extent, thereby realizing a periodic change in the pitch. The lift of the main rotor increases or decreases on the corresponding side, and the helicopter can achieve attitude movements such as pitch and roll.

[0045] The operation process of the present invention is as follows:

[0046] (1) After the engine 16 is started, the engine 16 outputs power backward to the tail rotor 14 through the power shaft 15, and the engine 16 outputs power forward to the main reducer 20 through the transmission shaft 17. The main reducer 20 transmits the decelerated power to the main rotor hub 7 and the main rotor blades 6 through the main rotor shaft 8. The tail rotor 14 rotates to generate a counter torque for the device, and the main rotor blades 6 rotate to provide lift for the device.

[0047] (2) The outer end of the torque arm 4 is hinged to the outer edge fork of the dynamic ring 19 through a ball bearing, and the inner end of the torque arm 4 is clamped on the main rotor shaft 8. Its main function is to completely transmit the rotational motion of the main rotor shaft 8 to the dynamic ring 19, so that the dynamic ring 19 maintains the same relative position and rotation speed with the main rotor shaft 8, and at the same time does not hinder the dynamic ring 19 from moving up and down and rotating around the large ball hinge core 9.

[0048] (3) The outer end of the anti-torsion arm 22 is hinged to the outer edge of the stationary ring 21 through a ball bearing, and the inner end of the anti-torsion arm 22 is fixed to the housing of the main reducer 20. Its main function is to hold the stationary ring 21 to prevent it from rotating and prevent the stationary ring 21 from being rotated by the passive ring 19, while not hindering the up and down movement of the stationary ring 21 and the rotation around the large ball hinge core 9.

[0049] (4) When the total pitch of the main rotor blade 6 needs to be changed, the actuators of the three steering gears 23 are synchronously extended and retracted to the same length, and the actuators of the three steering gears 23 push and pull the fixed ring 21 synchronously, and the fixed ring 21 transmits the motion to the movable ring 19, and the movable ring 19 pushes and pulls the large ball hinge ring 10 through the tilter support rod 5, and the large ball hinge ring 10 slides up and down along the main rotor shaft 8, so that the movable ring 19 transmits the motion to the small tie rod 12. When the small tie rod 12 pushes and pulls the outer end transverse axis of the main rotor blade 6 to move up and down, the elastic ball bearing connected to the inner end transverse axis of the main rotor blade 6 deflects, and the angle of attack of the main rotor blade 6 changes, that is, the pitch change of the main rotor blade 6 is achieved;

[0050] Each small pull rod 12 pushes and pulls the corresponding main blade 6 to change the pitch in the same way, that is, the total pitch is changed, the lift of the main rotor is evenly increased or decreased, and the helicopter can achieve an ascending or descending movement.

[0051] (5) When it is necessary to achieve cyclic pitch change of the main blade 6, the actuators of the three steering gears 23 are extended and retracted to different lengths respectively, and the actuators of the three steering gears 23 push and pull the fixed ring 21 respectively, and the fixed ring 21 transmits the motion to the movable ring 19, and the movable ring 19 rotates around the large ball joint core 9 through the tilter support rod 5, so that the movable ring 19 transmits the motion to the small pull rod 12. When the small pull rod 12 pushes and pulls the main blade 6 to move up and down along the outer end transverse axis, the elastic ball bearing connected to the inner end transverse axis of the main blade 6 deflects, and the angle of attack of the main blade 6 changes, that is, the pitch change of the main blade 6 is achieved; each small pull rod 12 pushes and pulls the corresponding main blade 6 to change the pitch differently, that is, the cyclic change of the pitch is achieved, the lift of the main rotor increases or decreases on the corresponding side, and the helicopter can achieve attitude movements such as pitch and roll.

[0052] (6) The variable collective pitch motion and the cyclic variable pitch motion of the main blade 6 can be realized synchronously, and its principle is consistent with the principle of the variable collective pitch motion and the cyclic variable pitch motion of the main blade 6.

[0053] The key points of the present invention are as follows:

[0054] (1) The hollow column structure of the large ball joint core 9 is sleeved on the main rotor shaft 8 and can slide up and down along the main rotor shaft 8. The hollow ball structure of the large ball joint core 9 is wrapped in the large ball joint ring 10, forming a spherical clearance fit with the large ball joint ring 10. The large ball joint ring 10 can rotate around the hollow ball structure of the large ball joint core 9, and can also push the large ball joint core 9 to slide up and down along the main rotor shaft 8;

[0055] (2) The annular cabin 1, the annular housing 2, the large bearing 3, the main rotor hub 7, the main rotor shaft 8, the large ball joint core 9, the large ball joint ring 10, the dynamic ring 19, the main reducer 20, and the stationary ring 21 are all coaxial;

[0056] (3) The large ball hinge ring 10 is fixedly connected to the fixed ring 21 through the tilter support rod 5, and the fixed ring 21 is hinged to the movable ring 19 through the large bearing 3. The movable ring 19 and the fixed ring 21 can only rotate relative to each other, and the other dimensions are limited by the structure between the movable ring 19 and the fixed ring 21. Except for relative rotation, the movable ring 19 and the fixed ring 21 keep following each other in other movements;

[0057] (4) The inner end transverse axis of the main blade 6 is arranged at the leading edge of the blade, and the outer end transverse axis of the main blade 6 is arranged at the trailing edge of the blade. Therefore, there is a force arm between the inner and outer end transverse axes of the main blade 6. When the small pull rod 12 pushes and pulls the outer end transverse axis of the main blade 6 to move up and down, the elastic ball bearing connected to the inner end transverse axis of the main blade 6 deflects, and the angle of attack of the main blade 6 changes, that is, the pitch change of the main blade 6 is achieved;

[0058] (5) When the actuators of the three servos 23 are synchronously extended and retracted to the same length, each small pull rod 12 pushes and pulls the corresponding main blade 6 to change pitch in the same manner, thereby achieving a change in the total pitch. The lift of the main rotor increases or decreases evenly, and the helicopter can achieve an ascending or descending movement.

[0059] (6) When the actuators of the three servos 23 are extended or retracted to different lengths, each small pull rod 12 pushes and pulls the corresponding main blade 6 to change its pitch to a different extent, thereby achieving a periodic change in the pitch. The lift of the main rotor increases or decreases on the corresponding side, and the helicopter can achieve attitude movements such as pitch and roll.

[0060] The above only expresses the implementation mode of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. In addition, the parts not detailed in the present invention are all conventional technologies.

Claims

1. A helicopter rotor system, characterized in that: include: An annular cabin (1), an annular shell (2), a torque arm (4), a main rotor blade (6), a main rotor hub (7), a main rotor shaft (8), a large ball hinge core (9), a large ball hinge ring (10), a tail rotor shell (11), a small pull rod (12), a tail rotor cabin (13), a tail rotor (14), a power shaft (15), an engine (16), a transmission shaft (17), a main reducer support frame (18), a dynamic ring (19), a main reducer (20), a stationary ring (21), an anti-twist arm (22), and a plurality of steering gears (23); The inner cavity of the annular shell (2) is provided with an annular cabin (1), the outer central space is provided with a main rotor structure through a main reducer support frame (18), the rear end is provided with a tail rotor cabin (13) through a tail rotor shell (11), and a tail rotor (14) is arranged in the tail rotor cabin (13); The main reducer (20) is fixed at the center of the main reducer support frame (18), the upper end of the main reducer (20) extends out of the main rotor shaft (8), the upper end of the main rotor shaft (8) is connected to the main propeller hub (7), and the inner end of the main propeller blade (6) is hinged to the outer edge of the main propeller hub (7) via a transverse axis; The engine (16) is arranged at the rear of the annular cabin (1), the engine (16) outputs power backward to the tail rotor (14) through the power shaft (15), and the engine (16) outputs power forward to the main reducer (20) through the transmission shaft (17), and the main reducer (20) transmits the decelerated power to the main rotor hub (7) and the main rotor blades (6) through the main rotor shaft (8); A large ball hinge core (9) is provided between the main reducer (20) and the main propeller hub (7); the large ball hinge ring (10) is fixedly connected to the fixed ring (21), and the fixed ring (21) is hinged to the movable ring (19); the outer end of the torque arm (4) is hinged to the outer edge fork of the movable ring (19), and the inner end of the torque arm (4) is clamped on the main rotor shaft (8); the outer end of the anti-torsion arm (22) is hinged to the outer edge fork of the fixed ring (21), and the inner end of the anti-torsion arm (22) is fixedly connected to the main reducer (20) housing; the small pull rod ( 12) is hinged to the outer edge fork of the moving ring (19) through the ball bearing at its lower end, and is hinged to the outer end transverse axis of the main blade (6) through the ball bearing at its upper end; the inner end transverse axis of the main blade (6) is arranged at the leading edge of the blade, and the outer end transverse axis of the main blade (6) is arranged at the trailing edge of the blade; a plurality of steering gears (23) are evenly distributed on the same horizontal plane and vertically installed on the main reducer support frame (18), and the actuator cylinder of the steering gear (23) is hinged to the outer edge fork of the fixed ring (21) through the ball bearing at its upper end; The annular cabin (1), the annular casing (2), the main rotor hub (7), the main rotor shaft (8), the large ball hinge core (9), the large ball hinge ring (10), the dynamic ring (19), the main reducer (20), and the stationary ring (21) are coaxially arranged.

2. The helicopter rotor system according to claim 1, characterized in that: The outer end of the torque arm (4) is hinged to the outer edge fork of the moving ring (19) through a ball bearing; The outer end of the anti-twist arm (22) is hinged on the outer edge fork of the stationary ring (21) through a ball bearing.

3. The helicopter rotor system according to claim 1, characterized in that: The large ball hinge ring (10) is fixedly connected to the fixed ring (21) through the tilter support rod (5), and the fixed ring (21) is hinged to the movable ring (19) through the large bearing (3).

4. The helicopter rotor system according to claim 1, characterized in that: The large ball joint core (9) is a structure in which a hollow ball is fixedly sleeved on the outside of a hollow column. The hollow column structure of the large ball joint core (9) is sleeved on the main rotor shaft (8) and can slide up and down along the main rotor shaft (8); the hollow ball structure of the large ball joint core (9) is wrapped in the large ball joint ring (10) to form a spherical gap fit with the large ball joint ring (10). The large ball joint ring (10) can rotate around the hollow ball structure of the large ball joint core (9) and can also push the large ball joint core (9) to slide up and down along the main rotor shaft (8).

5. The helicopter rotor system according to claim 1, characterized in that: The small pull rod (12) is a two-force rod structure, with ball bearings at both ends and a solid rod in the middle.

6. The helicopter rotor system according to claim 1, characterized in that: The main blade (6) is composed of inner and outer end transverse axes and a middle airfoil section; the inner end transverse axis of the main blade (6) is hinged to the outer edge of the main hub (7) through an elastic ball bearing, and the outer end transverse axis of the main blade (6) is hinged to the upper end of a small pull rod (12) through an elastic ball bearing.

7. The helicopter rotor system according to claim 1, characterized in that: There are 3 servos (23). When the actuators of the three steering gears (23) are synchronously extended and retracted to the same length, each small pull rod (12) pushes and pulls the corresponding main blade (6) to change the pitch in the same manner, thereby achieving a change in the total pitch, and the lift of the main rotor increases or decreases uniformly, so that the helicopter achieves an ascending or descending movement.

8. The helicopter rotor system according to claim 7, characterized in that: When the actuators of the three steering gears (23) are extended or retracted to different lengths, each small pull rod (12) pushes and pulls the corresponding main blade (6) to change the pitch in different ways, thereby achieving a periodic change in the blade pitch. The lift of the main rotor increases or decreases on the corresponding side, and the helicopter achieves pitch and roll posture movements.

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