Electric direct-driven eVTOL rotor control device

Abstract

According to the electric direct-driven eVTOL rotor control device, a driving motor is an outer rotor motor, a stator of the driving motor is of a hollow structure, and a steering engine assembly is installed on the lower portion of the stator, upwards penetrates through the stator and is in driving connection with a variable-pitch mechanism assembly, so that the deflection angle of blades of a blade handle assembly is adjustable; the intermediate transmission link is reduced, the energy loss is reduced, the transmission efficiency is improved, and the reliability of the system is improved; the rotor mounting seat cylinder is upwards connected with the propeller hub lower cover and downwards connected with the stator mounting seat through a bearing, so that stable and reliable power transmission between the driving motor rotor and the propeller hub assembly is ensured, and vibration and noise are reduced; the anti-rotation rocker arm is arranged between the lead screw nut and the fixed ring sleeve, so that rotation interference is avoided, and the precision and stability of variable pitch control are improved; and the variable-pitch rocker arm is in running fit with the variable-pitch disc, so that the linear motion of the variable-pitch disc can be accurately converted into the deflection motion of the blades, and the accurate adjustment of the pitch angle of the blades is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of eVTOL accessories, and in particular to an electric direct-drive eVTOL rotor control device. Background Art

[0002] eVTOL, or electric vertical take-off and landing aircraft, is a new type of transportation that integrates technologies from multiple fields such as aerospace, new energy, and automated control. Its core advantage lies in the use of electric drive to achieve vertical take-off and landing, with the characteristics of flexible take-off and landing, low noise, and zero emissions. The rotor control device in the electric vertical take-off and landing aircraft plays a decisive role in the flight performance, stability, and safety of the aircraft.

[0003] Existing rotor control devices have many shortcomings. For example, in terms of power transmission, some use mechanical transmission systems, such as multi-stage gearboxes and drive shafts. These components not only increase the weight and complexity of the system, but also lead to serious energy loss, reduce overall efficiency, and limit the payload and flight radius of the aircraft; in terms of pitch control, traditional rotor pitch change mechanisms mostly rely on hydraulic or pneumatic systems. Although the hydraulic system can provide a large driving force, there are problems such as leakage risk, high maintenance cost and relatively slow response speed. The pneumatic system is greatly affected by the ambient air pressure and temperature, and it is difficult to achieve precise pitch control; at the same time, traditional rotor control devices perform poorly in terms of integration. The components are scattered and occupy a large amount of space, which is not conducive to the lightweight and miniaturized design of electric vertical take-off and landing aircraft.

[0004] Therefore, it is necessary to improve the structure of the existing rotor control device, which can not only reduce energy loss, improve transmission efficiency, enhance system reliability, and reduce vibration and noise, but also eliminate the gap in the pitch change mechanism, ensure the accuracy of control, and improve flight safety. At the same time, it can improve the accuracy and stability of pitch control and realize precise adjustment of the blade pitch angle. Summary of the Invention

[0005] In view of the structural shortcomings of the current rotor control device, the purpose of the present invention is to provide an electric direct-drive eVTOL rotor control device, which can not only reduce energy loss, improve transmission efficiency, enhance system reliability, and reduce vibration and noise, but also eliminate the gap in the pitch mechanism, ensure the accuracy of control, and improve flight safety. At the same time, it can improve the accuracy and stability of pitch control and realize precise adjustment of the blade pitch angle.

[0006] An electric direct-drive eVTOL rotor control device of the present invention includes a servo assembly, a pitch-changing mechanism assembly, a drive motor, a hub assembly, and a blade shank assembly that is transmission-coordinated with the pitch-changing mechanism assembly. The drive motor is an outer rotor motor, and the stator of the drive motor is a hollow structure. The servo assembly is installed at the lower part of the stator, and passes upward through the stator and the pitch-changing mechanism assembly and is drive-connected, so that the deflection angle of the blade of the blade shank assembly is adjustable.

[0007] Furthermore, the drive motor also includes a rotor and a rotor mounting seat, and the rotor mounting seat includes a rotor mounting seat cover and a rotor mounting seat cylinder. The radial outer side of the rotor mounting seat cover is connected to the rotor, and the radial inner side is fixedly connected to the rotor mounting seat cylinder and is located near the middle of the rotor mounting seat cylinder.

[0008] Furthermore, the rotor mounting seat cover is tilted downward toward the rotor mounting seat cylinder.

[0009] Furthermore, the rotor mounting seat cylinder extends upward and is connected to the hub lower cover of the hub assembly.

[0010] Furthermore, the drive motor further includes a stator mounting seat, and the rotor mounting seat cylinder extends downward and is connected to the stator mounting seat cylinder of the stator mounting seat via a bearing.

[0011] Furthermore, the servo assembly includes a servo turntable, a screw structure located on the servo turntable, a fixed ring sleeve and an anti-rotation rocker arm, the screw structure includes a ball screw fixed to the servo turntable and a screw nut, the screw nut is externally mounted on the ball screw and is threadedly connected to the ball screw;

[0012] The fixed ring sleeve is located on the upper part of the screw nut, and an anti-rotation rocker arm is arranged between the fixed ring sleeve and the screw nut.

[0013] Furthermore, the pitch change mechanism assembly includes a pitch change disc and a pitch change rod. The pitch change rod is connected to the fixed ring sleeve through a bearing. The pitch change disc is externally mounted on the pitch change rod and can be controlled to move axially.

[0014] Furthermore, the blade petiole assembly also includes a petiole and a pitch-changing rocker arm. One end of the petiole is fixedly connected to the blade, and the other end is connected to the pitch-changing rocker arm. The pitch-changing rocker arm is rotatably matched with the pitch-changing disk.

[0015] Furthermore, it also includes a thrust needle roller combination bearing and a needle roller bearing. The thrust needle roller combination bearing and the needle roller bearing are sequentially sleeved on the petiole from the inside to the outside, and are connected to the hub upper cover and the hub lower cover of the hub assembly.

[0016] Furthermore, the pitch change mechanism assembly further includes an anti-backlash spring and a limiting nut, wherein the anti-backlash spring is arranged near the top of the pitch change rod and is fixed by the limiting nut;

[0017] The anti-backlash spring is located on the upper part of the propeller hub upper cover and is in close contact with the upper part of the propeller hub upper cover.

[0018] Beneficial effects of the present invention: An electric direct-drive eVTOL rotor control device of the present invention, the driving motor is an outer rotor motor, and the stator of the driving motor is a hollow structure, the servo assembly is installed at the lower part of the stator, and passes through the stator and the pitch change mechanism assembly upward and is driven and connected, so that the deflection angle of the blade of the blade shank assembly is adjustable, reducing the intermediate transmission links, reducing energy loss, improving transmission efficiency, and enhancing system reliability; the rotor mounting seat tube is connected to the hub lower cover upward and is connected to the stator mounting seat downward through a bearing, ensuring stable and reliable power transmission between the driving motor rotor and the hub assembly, reducing vibration and noise; the anti-rotation rocker arm is arranged between the screw nut and the fixed ring sleeve, avoiding rotational interference, and improving the accuracy and stability of the pitch control; the pitch rocker arm and the pitch plate rotate in coordination, which can accurately convert the linear motion of the pitch plate into the deflection motion of the blade, thereby realizing precise adjustment of the blade pitch angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0020] Figure 1 An exploded view of the electric direct-drive eVTOL rotor control device of the present invention;

[0021] Figure 2 A longitudinal cross-sectional view of the electric direct-drive eVTOL rotor control device along the axial direction;

[0022] Figure 3 This is a schematic diagram of the connection between the servo assembly and the pitch-changing mechanism assembly;

[0023] Figure 4 Schematic diagram of the structure of the hub assembly;

[0024] Figure 5 It is a schematic diagram of the connection between the hub assembly and the blade shank assembly.

[0025] Figure 1: servo assembly; 101: servo turntable; 102: fixed ring; 103: anti-rotation rocker arm; 104: ball screw; 105: screw nut; 2: pitch change mechanism assembly; 201: pitch change plate; 202: pitch change rod; 203: angular contact bearing; 204: anti-backlash spring; 205: limit nut; 3: drive motor; 301: stator of drive motor; 302: rotor of drive motor; 303: rotor installation Seat; 3031, rotor mounting seat cover; 3032, rotor mounting seat cylinder; 304, stator mounting seat; 3041, stator mounting seat cover; 3042, stator mounting seat cylinder; 305, deep groove ball bearing; 4, hub assembly; 401, hub lower cover; 402, hub upper cover; 5, blade stalk assembly; 501, blade; 502, stalk; 503, pitch rocker arm; 504, thrust needle roller combination bearing; 505, needle roller bearing. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1-5 The present invention is described in further detail.

[0027] The embodiment of the present invention discloses an electric direct-drive eVTOL rotor control device, comprising a servo assembly 1, a pitch mechanism assembly 2, a drive motor 3, a hub assembly 4, and a blade shank assembly 5 that is in transmission with the pitch mechanism assembly 2. The drive motor 3 is an outer rotor motor, and the stator 301 of the drive motor 3 is a hollow structure. The servo assembly 1 is installed at the lower part of the stator 301 and passes upward through the stator 301 and is driven and connected to the pitch mechanism assembly 2, so that the deflection angle of the blade 501 of the blade shank assembly 5 is Adjustable, the drive motor 3 is an outer rotor motor, and its stator 301 adopts a hollow structure, which provides axial space for the installation and transmission of the steering gear assembly 1. The steering gear assembly 1 can be directly connected to the pitch change mechanism 2 through the stator 301, avoiding the additional transmission components in the traditional design, such as gears or couplings, simplifying the mechanical structure, reducing the number of parts and assembly complexity. The hollow design of the stator 301 enables the drive motor 3 and the steering gear assembly 1 to form a coaxial nested layout in the axial direction, without the need for additional radial space expansion, achieving a compact structure. Purpose: To effectively reduce the weight and volume of the entire aircraft; the servo assembly 1 passes upward through the stator 301 to directly drive the pitch control mechanism assembly 2, resulting in a short transmission chain and low energy loss. Compared with the indirect transmission method of the traditional servo-connecting rod-pitch control mechanism, it reduces mechanical clearance and hysteresis, and improves the real-time control response; the direct drive of the servo assembly 1 and the pitch control mechanism assembly 2 can achieve rapid and precise adjustment of the deflection angle of the blade 501 of the blade shank assembly 5. When the electric vertical take-off and landing aircraft switches between different flight modes such as vertical take-off and landing, hovering or forward flight, the pitch angle of each blade 501 can be adjusted in real time, optimizing lift distribution and torque balance, improving flight stability and maneuverability, reducing friction and elastic deformation caused by transmission components, so that the control signal of the servo assembly 1 can be more directly converted into the movement of the blade 501, and reducing control delay; the rotor 302 of the drive motor 3 directly drives the hub assembly 4 to rotate, with high drive efficiency. Generally, the torque density of the outer rotor motor is higher than that of the inner rotor motor, providing stronger starting torque and stable speed output, which will not be described in detail here.

[0028] In this embodiment, the drive motor 3 also includes a rotor 302 and a rotor mounting seat 303. The rotor mounting seat 303 includes a rotor mounting seat cover 3031 and a rotor mounting seat cylinder 3032. The radial outer side of the rotor mounting seat cover 3031 is connected to the rotor 302, and the radial inner side is fixedly connected to the rotor mounting seat cylinder 3032 and is located near the middle of the rotor mounting seat cylinder 3032. The radial outer side of the rotor mounting seat cover 3031 is connected to the rotor 302, and the radial inner side is fixed to the middle of the rotor mounting seat cylinder 3032. Near the part, a composite structure combining an annular support and a central axis is formed, which evenly transmits the centrifugal force of the rotor 302 during rotation and the load of the blades 501 to the rotor mounting seat cylinder 3032 through the rotor mounting seat cover 3031, thereby avoiding local stress concentration and improving the overall structural strength. The rigid connection between the rotor mounting seat cover 3031 and the rotor mounting seat cylinder 3032, such as bolt fixing or integral molding, can enhance the torsional rigidity of the rotor 302, reduce deformation during high-speed rotation, and reduce the risk of component loosening due to vibration; the rotor The sub-mounting seat cover 3031 is located near the middle of the rotor mounting seat cylinder 3032, so that the center of gravity of the rotor 302 is closer to the axis of the drive motor 3, reducing the eccentricity. When the drive motor 3 rotates at high speed, the dynamic imbalance can be reduced, the vibration noise can be reduced, and the wear of supporting components such as bearings can be reduced, thereby extending the service life of the drive motor 3. The rotor mounting seat cylinder 3032 serves as the central axis, and its axis is coaxial with the stator 301 and the transmission shaft of the steering gear assembly 1, ensuring that the hub assembly 4 remains concentric with the rotor 302 after installation, avoiding The vibration and noise caused by eccentricity are reduced, and the operating stability of the rotor system is improved; the rotor mounting seat cylinder 3032 is a hollow structure, which echoes the hollow design of the stator 301, and can form a ventilation channel running through the axial direction of the drive motor 3. When the drive motor 3 is running, air can flow through the inside of the rotor mounting seat cylinder 3032, taking away the heat generated by the windings and bearings of the rotor 302. Especially under the design of fixing the middle part of the rotor mounting seat cylinder 3032, the airflow can be evenly distributed to the inside and outside of the rotor 302, thereby improving the heat dissipation efficiency. I will not go into details here.

[0029] In this embodiment, the rotor mounting seat cover 3031 is tilted downwardly toward the rotor mounting seat tube 3032. The rotor mounting seat cover 3031 is tilted downwardly toward the rotor mounting seat tube 3032, that is, it has a certain taper from the radial outer side to the inner side of the rotor mounting seat cover 3031, forming a curved surface structure similar to a guide cone. When the drive motor 3 rotates at high speed, when the air flows through the outer side of the rotor 302 and the surface of the rotor mounting seat cover 3031, the streamlines are smoothly transitioned due to the inclined surface, reducing airflow separation and vortex generation, and reducing aerodynamic resistance. The inclined surface can avoid the edge of the rotor mounting seat cover 3031 from forming a right-angle impact with the airflow, reducing airflow turbulence and noise generation. By designing the rotor mounting seat cover 3031 as an inclined conical surface, the airflow flows evenly along the curved surface, reducing high-frequency noise generated by airflow disturbances; the rotor 3 02 The centrifugal force generated during rotation is radially outward, and the inclined rotor mounting cover 3031 can convert part of the radial force into axial force, pointing in the direction of the rotor mounting tube 3032. This force decomposition can reduce the radial stress at the connection between the rotor mounting cover 3031 and the rotor 302, especially under high-speed conditions, which can reduce the risk of deformation of the edge of the rotor mounting cover 3031 and improve the durability of the structure; the inclined surface makes the rigidity of the rotor mounting cover 3031 more evenly distributed, and compared with the horizontal cover, its resonance frequency when vibrated is higher, reducing fatigue cracks caused by resonance; the downward tilt of the rotor mounting cover 3031 can reduce its axial height, providing a more compact installation space for the blade petiole assembly 5 above, reserving sufficient space for the petiole movement, and ensuring the flexible movement of the pitch mechanism assembly 2, which will not be repeated here.

[0030] In this embodiment, the rotor mounting seat tube 3032 extends upward and is connected to the hub lower cover 401 of the hub assembly 4. After the rotor mounting seat tube 3032 extends upward and is connected to the hub lower cover 401, the rotational power of the rotor 302 of the drive motor 3 can be directly transmitted to the hub assembly 4 through the rotor mounting seat tube 3032, avoiding the energy loss when transmitting through intermediate connectors such as couplings in traditional designs. Axial loads, such as lift and gravity generated by blades, can be directly transmitted to the stator 301 through the rotor mounting seat tube 3032, reducing structural deformation; the rigid connection between the rotor mounting seat tube 3032 and the hub assembly 4 shortens The power transmission path reduces the fluctuation of the system's rotational inertia and the vibration caused by inertia mismatch, especially suppresses the swing phenomenon of the blade 501 and improves flight stability; the rotor mounting seat tube 3032 extends upward and directly connects to the hub lower cover 401, eliminating the need for an independent transmission shaft or extension piece, shortening the axial height of the entire rotor control device, and the rotor mounting seat tube 3032 is a hollow structure, continuing the hollow design of the stator 301, and can accommodate the control cable of the pitch change mechanism assembly 2, the signal line of the servo assembly 1 and the temperature sensor lead, etc., to avoid wear or aerodynamic resistance caused by exposed cables, simplifying the wiring process, which will not be repeated here.

[0031] In this embodiment, the drive motor 3 also includes a stator mounting seat 304, the rotor mounting seat tube 3032 extends downward and is connected to the stator mounting seat tube 3042 of the stator mounting seat 304 through a bearing, and the rotor mounting seat tube 3032 extends downward to the stator mounting seat 304 and is connected through a deep groove ball bearing 305 to form a double-point support structure. When the blade 501 is deflected by aerodynamic interference, the deep groove ball bearing 305 can withstand the radial force caused by the eccentricity of the rotor 302, avoiding friction between the rotor 302 and the stator 301. The deep groove ball bearing 305 can offset the axial magnetic pull and the lift reaction force of the blade 501 during the operation of the drive motor 3, preventing the rotor 302 from axial movement and reducing the rotation speed. The rotor 302 vibrates and generates noise; the rotor 302 needs to rotate around the stator 301, and the deep groove ball bearing 305 is connected to form a relative rotation pair between the rotor mounting seat tube 3032 and the stator mounting seat 304. The stator mounting seat 304 is fixed, and the rotor 302 drives the hub assembly 4 to rotate through the rotor mounting seat tube 3032, which has a high power transmission efficiency. The high-precision matching of the deep groove ball bearing 305 can ensure the coaxiality of the rotor 302 and the stator 301, avoid the magnetic resistance torque fluctuation caused by uneven air gap, and improve the speed regulation stability; the bearing support can reduce the transmission of the rotor 302 vibration to the stator mounting seat 304, and protect the electronic equipment inside the fuselage from vibration damage. I will not go into details here.

[0032] In this embodiment, the servo assembly 1 includes a servo turntable 101, a screw structure located on the servo turntable 101, a fixed ring sleeve 102 and an anti-rotation rocker arm 103, the screw structure includes a ball screw 104 and a screw nut 105 fixed on the servo turntable 101, the screw nut 105 is outermostly mounted on the ball screw 104 and is threadedly connected to the ball screw 104, the ball screw 104 transmits power through rolling contact between the balls and the screw nut 105, and has high transmission efficiency. The pre-tightening design of the ball screw 104 can eliminate axial clearance and avoid backlash error caused by vibration of the electric vertical take-off and landing aircraft during flight; the ball screw The lead screw 104 is directly fixed to the center of the servo turntable 101, and the lead screw nut 105 is externally mounted on the ball screw 104 and connected to the pitch change mechanism assembly 2, forming a coaxial transmission chain of the servo turntable 101-ball screw 104-lead screw nut 105. The axial dimension is compressed, which is convenient for integration. The ball screw 104 and the lead screw nut 105 cooperate to efficiently convert the rotational motion of the servo turntable 101 into linear motion. The anti-rotation rocker arm 103 cooperates with the fixed ring sleeve 102 to limit the rotational freedom of the lead screw nut 105, ensuring that the lead screw nut 105 can only slide along the axial direction of the ball screw 104, avoiding rotation interference and improving the accuracy and stability of pitch change control.

[0033] The fixed ring sleeve 102 is located at the upper part of the screw nut 105, and an anti-rotation rocker arm 103 is set between the fixed ring sleeve 102 and the screw nut 105. The two ends of the anti-rotation rocker arm 103 are respectively hinged to the fixed ring sleeve 102 and the screw nut 105 to form a motion constraint combining a rotating pair and a moving pair. When the servo turntable 101 drives the ball screw 104 to rotate, the screw nut 105 should generate axial movement and rotation at the same time, but the anti-rotation rocker arm 103 limits its rotation through the fixed fulcrum of the fixed ring sleeve 102, retaining only the axial movement degree of freedom, thereby avoiding pitch control deviation caused by rotation; the length of the anti-rotation rocker arm 103 It forms a geometric proportional relationship with the lead of the ball screw 104. When there is a cumulative pitch error in the ball screw 104, the flexible hinge of the anti-rotation rocker arm 103 can absorb part of the radial deviation to prevent jamming caused by the accumulated error; when the screw nut 105 is subjected to lateral force, such as the aerodynamic eccentricity when the blade 501 changes pitch, the anti-rotation rocker arm 103 and the fixed ring sleeve 102 form a triangular support structure to avoid local wear of the ball screw 104 due to eccentric load; the anti-rotation rocker arm 103 transmits part of the axial force of the screw nut 105 to the servo assembly 1 through the fixed ring sleeve 102, reducing the axial load borne by the ball screw 104 alone.

[0034] In this embodiment, the pitch change mechanism assembly 2 includes a pitch change plate 201 and a pitch change rod 202. The pitch change rod 202 is connected to the fixed ring sleeve 102 through a bearing. The pitch change plate 201 is outermost on the pitch change rod 202 and can be controlled to move axially. The pitch change rod 202 is connected to the fixed ring sleeve 102 through an angular contact bearing 203, forming a motion constraint combining a rotating pair and a moving pair. The angular contact bearing 203 allows the pitch change rod 202 to rotate freely with the rotor main shaft to avoid lubrication failure due to frictional heat. The pitch change plate 201 is outermost on the pitch change rod 202, and its axial movement is driven by the servo assembly 1 through a screw structure. The axial limit of the angular contact bearing 203 prevents the pitch change The rod 202 moves axially to ensure the movement accuracy of the pitch disc 201; when there is a coaxiality error in the rotor main shaft, the self-aligning ability of the angular contact bearing 203 can absorb the radial deviation and avoid the rigid interference between the pitch rod 202 and the fixed ring sleeve 102; this design also optimizes the transmission efficiency and reduces friction loss and energy loss; the axial force generated by the axial movement of the pitch disc 201 is transmitted to the inner ring of the angular contact bearing 203 through the pitch rod 202, and then transmitted to the servo assembly 1 through the outer ring of the angular contact bearing 203 through the fixed ring sleeve 102, and the radial force generated by the rotation of the rotor is directly borne by the angular contact bearing 203, realizing the diversion and transmission of axial and radial loads, which will not be repeated here.

[0035] In this embodiment, the blade petiole assembly 5 also includes a petiole 502 and a pitch-changing rocker arm 503, one end of the petiole 502 is fixedly connected to the blade 501, and the other end is connected to the pitch-changing rocker arm 503, the pitch-changing rocker arm 503 rotates with the pitch-changing disk 201, the petiole 502 connects the blade 501 and the pitch-changing rocker arm 503, the pitch-changing rocker arm 503 rotates with the pitch-changing disk 201, forming a transmission path of blade 501-petiole 502-pitch-changing rocker arm 503-pitch-changing disk 201, when the pitch-changing disk 201 is driven to change its angle or position, the petiole 502 can be driven to rotate by the pitch-changing rocker arm 503, thereby changing the pitch angle of the blade 501, the pitch angle is the angle between the chord line of the cross section of the blade 501 and the rotation plane, which will not be repeated here; this structure allows the pitch angle to be adjusted in real time by the pitch-changing disk 201 Linked control is used to achieve switching between different flight states such as ascent, descent or hovering, or in the variable-pitch propeller of an electric vertical take-off and landing aircraft, to optimize the propulsion efficiency at different speeds; one end of the petiole 502 is fixedly connected to the blade 501, and the other end is connected to the pitch rocker arm 503 to form a rigid structure, ensuring that the driving force of the pitch disc 201 can be accurately transmitted to the blade 501, reducing deformation or energy loss during the transmission process, and the rotational coordination of the pitch rocker arm 503 and the pitch disc 201, such as through connectors such as bearings or pins, not only ensures the smoothness of the pitch change action, but also can withstand the centrifugal force and aerodynamic load when the blade 501 rotates, avoiding control failure due to structural looseness; a reasonable pitch structure design can reduce the fluctuation of the aerodynamic load of the blade 501, thereby reducing vibration and noise during flight and improving the comfort and reliability of the system.

[0036] In this embodiment, a thrust needle roller combination bearing 504 and a needle roller bearing 505 are also included. The thrust needle roller combination bearing 504 and the needle roller bearing 505 are sequentially sleeved on the blade stalk 502 from the inside to the outside, and are connected to the hub upper cover 402 and the hub lower cover 401 of the hub assembly 4. The thrust needle roller combination bearing 504 mainly bears the axial thrust generated when the blade 501 rotates. Its combined structure can withstand radial force and axial force at the same time, avoiding local wear caused by load concentration. The needle roller bearing 505 mainly bears radial loads, such as the centrifugal force when the blade 501 rotates. The slender structure of the needle roller provides a larger contact area, reduces the pressure per unit area, and extends the service life of the bearing. The cooperation of the thrust needle roller combination bearing 504 and the needle roller bearing 505 enables the axial and radial loads to be transmitted independently, reduces the load interference between the bearings, and improves the overall load-bearing capacity. The bearings distribute the load to the hub upper cover 402 and the hub lower cover 401, avoiding stress concentration in a local area of ​​the blade stalk 502 and enhancing the fatigue resistance of the structure. Usually, the rolling friction coefficient of the bearings is much lower than the sliding friction, so that the blade stalk 502 rotates more smoothly during the pitch change process, reducing the energy loss required to drive the pitch change. For systems that require frequent pitch changes, the load of the pitch change mechanism component 2 can be reduced, and the service life of driving components such as hydraulic systems or motors can be extended. The high-precision manufacturing process of the bearings ensures that the rotation error of the blade stalk 502 is extremely small, so that the pitch change angle of the blade 501 can accurately follow the control instructions of the pitch change disk 201, thereby improving the accuracy of flight control. The thrust needle roller combination bearing 504 and the needle roller bearing 505 are mounted on the blade stalk 502 to form an independent component, which can be assembled to the hub component 4 as a whole, simplifying the assembly process on the production line and improving assembly efficiency.

[0037] In this embodiment, the pitch change mechanism assembly 2 also includes an anti-backlash spring 204 and a limiting nut 205. The anti-backlash spring 204 is arranged near the top of the pitch change rod 202 and is fixed by the limiting nut 205. The anti-backlash spring 204 is fixed to the top of the pitch change rod 202 by the limiting nut 205, and applies an axial pre-tightening force to the pitch change rod 202, so that the various components in the transmission chain always maintain close contact. The elastic deformation ability of the anti-backlash spring 204 can absorb the gap caused by vibration or wear in real time, ensuring that the pitch change command can be transmitted to the blade 501 immediately and accurately; during flight, the aerodynamic load fluctuations of the blade 501 will be transmitted to the control system through the pitch change mechanism assembly 2, and the anti-backlash spring 204 will be fixed to the top of the pitch change rod 202 by the limiting nut 205. The elastic deformation of the clearance spring 204 can dissipate part of the vibration energy and reduce the risk of structural fatigue. For a high-speed rotating blade system, the damping effect of the clearance-eliminating spring 204 can suppress the resonance phenomenon and avoid violent vibration caused by frequency coupling. By adjusting the tightening degree of the limit nut 205, the preload force of the clearance-eliminating spring 204 can be accurately controlled, so that the pitch-changing mechanism assembly 2 can maintain the best force transmission efficiency under different working conditions. The appropriate preload force can reduce the relative sliding friction between components and reduce the energy consumption required for driving the pitch change. After the clearance is eliminated, the relative displacement between the components is reduced, and the friction and wear are reduced accordingly, thereby extending the service life of key components such as the pitch-changing rod 202 and the spherical bearing.

[0038] The anti-backlash spring 204 is located on the upper part of the propeller hub cover 402 and is in close contact with the upper part of the propeller hub cover 402. The anti-backlash spring 204 is in close contact with the upper part of the propeller hub cover 402, and directly transmits the axial load of the pitch change rod 202 to the propeller hub assembly 4, thereby avoiding the load from being transmitted through other non-designed paths and reducing the additional stress between components. The close arrangement of the anti-backlash spring 204 and the propeller hub cover 402 shortens the load transmission path, reduces the bending moment effect caused by the excessively long lever arm, and reduces the risk of bending deformation of the pitch change rod 202. The anti-backlash spring in close contact 204 forms a rigid support with the hub cover 402, which can effectively suppress the lateral swing of the pitch rod 202 and reduce fatigue cracks caused by vibration; the pre-tightening force of the anti-backlash spring 204 on the hub cover 402 eliminates the potential gap between the pitch rod 202 and the hub assembly 4, avoids loosening due to the gap, and reduces component wear and abnormal noise; the anti-backlash spring 204 is arranged on the upper part of the hub cover 402, and there is no need to set an additional spring receiving structure inside the hub assembly 4, which simplifies the internal space design of the hub assembly 4 and provides more installation space for other components.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An electric direct-drive eVTOL rotor control device, characterized by: It includes a servo assembly, a pitch-changing mechanism assembly, a drive motor, a hub assembly, and a blade shank assembly that cooperates with the pitch-changing mechanism assembly. The drive motor is an outer rotor motor, and the stator of the drive motor is a hollow structure. The servo assembly is installed at the lower part of the stator, and passes upward through the stator and the pitch-changing mechanism assembly and is driven and connected, so that the deflection angle of the blade of the blade shank assembly is adjustable.

2. The electric direct drive eVTOL rotor control device according to claim 1, characterized in that: The drive motor also includes a rotor and a rotor mounting seat. The rotor mounting seat includes a rotor mounting seat cover and a rotor mounting seat cylinder. The radial outer side of the rotor mounting seat cover is connected to the rotor, and the radial inner side is fixedly connected to the rotor mounting seat cylinder and is located near the middle of the rotor mounting seat cylinder.

3. The electric direct drive eVTOL rotor control device according to claim 2, characterized in that: The rotor mounting seat cover is tilted downward toward the rotor mounting seat cylinder.

4. The electric direct drive eVTOL rotor control device according to claim 2, characterized in that: The rotor mounting seat cylinder extends upward and is connected to the hub lower cover of the hub assembly.

5. The electric direct drive eVTOL rotor control device according to claim 2, characterized in that: The driving motor further includes a stator mounting seat, and the rotor mounting seat cylinder extends downward and is connected to the stator mounting seat cylinder of the stator mounting seat through a bearing.

6. The electric direct drive eVTOL rotor control device according to claim 1, characterized in that: The servo assembly includes a servo turntable, a screw structure located on the servo turntable, a fixed ring sleeve and an anti-rotation rocker arm, the screw structure includes a ball screw and a screw nut fixed to the servo turntable, the screw nut is externally mounted on the ball screw and is threadedly connected to the ball screw; The fixed ring sleeve is located on the upper part of the screw nut, and an anti-rotation rocker arm is arranged between the fixed ring sleeve and the screw nut.

7. The electric direct drive eVTOL rotor control device according to claim 1, characterized in that: The pitch change mechanism assembly includes a pitch change disc and a pitch change rod. The pitch change rod is connected to a fixed ring sleeve through a bearing. The pitch change disc is externally mounted on the pitch change rod and can be controlled to move axially.

8. The electric direct drive eVTOL rotor control device according to claim 7, characterized in that: The blade petiole assembly also includes a petiole and a pitch-changing rocker arm. One end of the petiole is fixedly connected to the blade, and the other end is connected to the pitch-changing rocker arm. The pitch-changing rocker arm is rotatably matched with the pitch-changing disk.

9. The electric direct drive eVTOL rotor control device according to claim 8, characterized in that: It also includes a thrust needle roller combination bearing and a needle roller bearing. The thrust needle roller combination bearing and the needle roller bearing are sequentially sleeved on the petiole from the inside to the outside, and are connected to the propeller hub upper cover and the propeller hub lower cover of the propeller hub assembly.

10. The electric direct drive eVTOL rotor control device according to claim 7, characterized in that: The pitch change mechanism assembly further includes an anti-backlash spring and a limit nut, wherein the anti-backlash spring is arranged near the top of the pitch change rod and is fixed by the limit nut; The anti-backlash spring is located on the upper part of the propeller hub upper cover and is in close contact with the upper part of the propeller hub upper cover.

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