Electric drive power wheel system based on multi-stage vibration reduction design

Abstract

The invention discloses an electrically-driven power wheel system based on multi-stage vibration reduction design, and relates to the technical field of new energy carrying systems. The electric vehicle wheel driving device is applied to the field of electric vehicle wheel driving and comprises a hub installed on a wheel, the center position of the hub is rotationally connected with a supporting shaft, a motor shell is fixedly installed on the outer surface of the supporting shaft, and a stator and a planetary gear speed reduction assembly are installed in the motor shell; and a first vibration reduction structure is mounted between the planetary gear speed reduction assembly and the hub. Additional masses of a hub motor and a steering servo motor are decoupled from unsprung masses through rubber elements and in-wheel shock absorbers, and the newly added unsprung masses are converted into dynamic shock absorption advantages by reconstructing a parallel-series composite vibration topology. The problem of vertical dynamic characteristic deterioration caused by unsprung mass increase due to introduction of a driving motor and a steering motor is effectively solved, the wheel grounding performance is improved, and the service life of parts is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle systems, and specifically to an electric drive power wheel system based on multi-stage vibration damping design. Background Art

[0002] With the innovation of electrification and intelligent technologies in new energy vehicle systems, the integration and modularization of vehicle chassis have become important development directions. The corner module technology integrates the drive, brake, suspension, and steering systems into an integrated assembly, significantly reducing mechanical transmission components and optimizing the vehicle's overall space layout. Based on this technology, each wheel can achieve independent drive and steering, greatly improving the vehicle's mobility and handling flexibility. At the same time, the distributed drive architecture further enhances driving safety through multi-wheel redundancy design.

[0003] In the corner module, the in-wheel motor, as the core drive component, is embedded inside the wheel hub and is connected to the wheel through a flange to drive it to rotate forward and backward. The knuckle is rigidly connected to the support shaft, and the knuckle is connected to the vehicle body through a suspension swing arm. The suspension damping system is installed between the upper swing arm and the vehicle body to attenuate the vibration energy transmitted from the road excitation to the vehicle body and ensure vehicle ride comfort. However, the introduction of the in-wheel motor and the steering motor arranged on the upper suspension swing arm has significantly increased the unsprung mass of the corner module, thereby deteriorating the vertical dynamic performance, specifically manifested as increased vehicle body vibration, fluctuations in tire grounding characteristics, and decreased ride comfort. To improve ride comfort and address the problems caused by the increase in unsprung mass, a large number of studies have been conducted to suppress the vertical negative effects, and various solutions have been proposed, such as motor weight reduction, in-wheel suspension systems, and active and semi-active suspensions. The lightweighting of the in-wheel motor, suspension, and wheel hub is an effective way to reduce the mass of the electric wheel. However, in the current research and development of corner modules, there are relatively few structural designs for vibration damping problems.

[0004] The existing patent (Publication No.: CN110154736B) discloses an electric wheel with in-wheel damping function. This device uses a composite damping structure of an annular hydraulic bushing and a double swing arm suspension. However, the coordinated action of the large and small shock absorbers, swing arms, and stabilizer bars in the suspension depends on complex rotating pair connections, resulting in a delay in the system's dynamic response and affecting the suppression efficiency of high-frequency vibrations. In addition, the rotor housing and the wheel rim transmit torque through the slot-pin structure of the central drive disk. This mechanical coupling method is prone to clearance wear under long-term impact loads, resulting in a decrease in the stability of the motor magnetic gap and affecting the output torque accuracy. Therefore, the present invention proposes an electric drive power wheel system based on multi-stage vibration damping design. Summary of the Invention

[0005] The object of the present invention is to provide an electric drive power wheel system based on multi-stage vibration damping design. By means of rubber elements and in-wheel shock absorbers, the additional masses of the hub drive motor and the steering motor are decoupled from the unsprung mass. By reconstructing the parallel-series composite vibration topology, the newly added unsprung mass is transformed into the advantage of dynamic vibration absorption, effectively solving the problem of deterioration of the vertical dynamic characteristics caused by the increase in unsprung mass due to the introduction of the drive motor and the steering motor, and improving the wheel grounding performance and the service life of components.

[0006] To achieve the above object, the present invention provides the following technical solution: An electric drive power wheel system based on multi-stage vibration damping design, which is applied to the field of electric vehicle wheel drive, includes a hub installed on the wheel. A support shaft is rotatably connected to the central position of the hub. An outer surface of the support shaft is fixedly provided with a motor housing. A stator and a planetary gear reduction assembly are installed inside the motor housing, and a first vibration damping structure is installed between the planetary gear reduction assembly and the hub to attenuate the high-frequency vibration of the motor;

[0007] A second vibration damping structure is installed between the motor housing and the support shaft to block the transmission of medium-frequency vibration to the suspension system;

[0008] The suspension system includes a steering knuckle. The upper and lower ends of the steering knuckle are respectively hinged to an upper cross arm and a lower cross arm. The support shaft passes through a central hole of the steering knuckle, and a third vibration damping structure is provided between the steering knuckle and the support shaft to absorb the low-frequency vibration caused by road surface undulations.

[0009] Further, the hub and the support shaft are rotatably connected through a hub bearing.

[0010] Further, the stator and the motor housing are both fixedly connected to the support shaft. An inner part of the motor housing is rotatably connected with a motor rotor hub. The motor rotor hub and the support shaft are rotatably connected through a motor rotor hub bearing.

[0011] Further, a rotor is installed on a side wall of the motor rotor hub, and the planetary gear reduction assembly is also installed on the motor rotor hub.

[0012] Further, the planetary gear reduction assembly includes a sun gear, planet gears, a planet carrier and a ring gear. The sun gear is connected to the motor rotor hub. The ring gear is fixedly connected to the motor housing through a flange. The planet gears and the planet carrier are connected through planet pins. The planet carrier is connected to the hub through a connecting bolt and the first vibration damping structure. The planet carrier forms a rotational pair connection with the support shaft through a planet carrier bearing.

[0013] Further, both the first vibration damping structure and the third vibration damping structure are provided as rubber elements with viscoelasticity;

[0014] The second damping structure includes a rubber element and an in-wheel shock absorber disposed between the motor housing and the support shaft;

[0015] The in-wheel shock absorber adopts a single-cylinder integrated passive damping structure arranged symmetrically up and down. The in-wheel shock absorber includes two sets of coaxially nested hydraulic damping units and a helical spring shock absorber. The hydraulic damping unit is a single-cylinder passive hydraulic damper, and a displacement sensor is provided at the end of the helical spring shock absorber housing for real-time detection of the relative displacement between the support shaft and the motor housing.

[0016] Further, a steering servo motor is meshingly installed on the knuckle, and the steering servo motor is rigidly connected to the upper cross arm through a steering motor support.

[0017] Further, the steering servo motor includes a worm and worm gear reducer with a self-locking function. The output shaft of the steering servo motor meshes with the inner hole of the knuckle through an involute spline, and the axis of the output shaft of the steering servo motor passes through the center of rotation of the knuckle and the center of the ball joint of the lower cross arm.

[0018] Further, the suspension system further includes an air spring and a magnetorheological damper. The air spring and the magnetorheological damper are arranged in parallel. The working cylinder of the magnetorheological damper is filled with magnetorheological fluid, and a step change in damping force is achieved through an electromagnetic coil.

[0019] Further, the upper end of the knuckle is connected to the left end of the upper cross arm, and the lower end is connected to the left end of the lower cross arm, and two rotating pairs are formed. The right ends of the upper and lower cross arms are both connected to the vehicle frame through rotating pairs;

[0020] The lower end of the magnetorheological damper forms a rotating pair with the lower cross arm, and the upper end is connected to the vehicle frame through a ball joint.

[0021] The present invention has at least the following beneficial effects:

[0022] 1. In the present invention, the additional masses of the hub drive motor and the steering motor are decoupled from the unsprung mass through the rubber element and the in-wheel shock absorber. By reconstructing the parallel-series composite vibration topology, the newly added unsprung mass is transformed into the advantage of dynamic vibration absorption. Therefore, starting from the frequency-domain decoupling mechanism of the vibration energy transmission path, the problem of deterioration of the vertical dynamic characteristics caused by the increase in unsprung mass introduced by the drive motor and the steering motor is effectively solved, and the wheel grounding performance and the service life of components are improved.

[0023] 2. The present invention filters vibrations in layers through a three-stage damping structure. The combination of the rubber element, the in-wheel shock absorber and the suspension shock absorber realizes vibration suppression in the full frequency band. For vertical dynamics, the controllable degrees of freedom are increased.

[0024] 3. The steering mechanism topology of the present invention is reconstructed by canceling the traditional mechanical steering rod system and directly driving the wheels with a distributed electronically controlled steering actuator unit, avoiding the interference problem between the suspension guiding mechanism and the steering transmission chain. The designed steering system has the ability of full circumferential steering, enabling the vehicle to complete fixed-point steering with a minimum turning radius and lateral movement functions.

[0025] 4. The angular module integrating in-wheel damping and viscoelastic rubber elements of the present invention also has the advantages of simple and compact overall structure, small volume and light weight.

[0026] Of course, it is not necessary for any product implementing the present invention to achieve all the above-mentioned advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic cross-sectional view of the overall structure of the present invention;

[0028] Figure 2 is a structure and model structure diagram of the electric drive power wheel system of the present invention, where (a) is the structure diagram of the electric drive power wheel system and (b) is the 1 / 4 model structure diagram of the electric drive power wheel vehicle;

[0029] Figure 3 is a schematic diagram comparing the amplitudes of the sprung mass acceleration of the angular module of the present invention with that of the traditional angular module;

[0030] Figure 4 is a schematic diagram comparing the amplitudes of the tire dynamic load of the angular module of the present invention with that of the traditional angular module.

[0031] REFERENCE SIGNS:

[0032] 1. Wheel; 2. Motor housing; 3. Stator; 401. First damping structure; 402. Second damping structure; 403. Third damping structure; 5. Bolt; 6. Planet carrier; 7. Planet carrier bearing; 8. Hub; 9. Hub bearing; 10. Support shaft; 11. Motor rotor hub bearing; 12. Planet pin; 13. Planetary gear reduction assembly; 14. Motor rotor hub; 15. Rotor; 16. Steering servo motor; 17. Steering motor support; 18. Upper cross arm; 19. Magnetorheological damper; 20. Lower cross arm; 21. Steering knuckle; 22. In-wheel damper. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure. Apparently, the described embodiments are only a part rather than all of the embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0034] Please refer toFigure 1 , the present invention provides a technical solution: an electric drive power wheel system based on multi-stage vibration damping design, which is applied to the field of driving of electric vehicle wheel 1, and includes a hub 8 installed on the wheel 1. A support shaft 10 is rotatably connected to the central position of the hub 8. A motor housing 2 is fixedly installed on the outer surface of the support shaft 10. A stator 3 and a planetary gear reduction assembly are installed inside the motor housing 2. And a first vibration damping structure 401 is installed between the planetary gear reduction assembly and the hub 8 for attenuating the high-frequency vibration of the motor;

[0035] A second vibration damping structure 402 is installed between the motor housing 2 and the support shaft 10 for blocking the transmission of medium-frequency vibration to the suspension system;

[0036] The suspension system includes a steering knuckle 21. The upper and lower ends of the steering knuckle 21 are respectively hinged to an upper cross arm 18 and a lower cross arm 20. The support shaft 10 passes through the central hole of the steering knuckle 21. And a third vibration damping structure 403 is arranged between the steering knuckle 21 and the support shaft 10 for absorbing the low-frequency vibration caused by road surface undulations.

[0037] For the technical solution of this embodiment, the hub 8 and the support shaft 10 are rotatably connected through a hub bearing 9 for realizing radial support.

[0038] For the technical solution of this embodiment, the stator 3 and the motor housing 2 are both fixedly connected to the support shaft 10. A motor rotor hub 14 is rotatably connected inside the motor housing 2. The motor rotor hub 14 and the support shaft 10 are rotatably connected through a motor rotor hub 14 bearing 11. During actual driving, the planetary gear reduction assembly serves as the power output end.

[0039] For the technical solution of this embodiment, a rotor 15 is installed on the side wall of the motor rotor hub 14, and the planetary gear reduction assembly is also installed on the motor rotor hub 14.

[0040] For the technical solution of this embodiment, the planetary gear reduction assembly includes a sun gear, a planetary gear, a planet carrier 6 and a ring gear. The sun gear is used as the input end and is connected to the motor rotor hub 14. The ring gear is fixedly connected to the motor housing 2 through a flange. The planetary gear and the planet carrier 6 are connected through a planetary pin 12. The planet carrier 6 is connected to the hub 8 through a connecting bolt 5 and the first vibration damping structure 401. The planet carrier 6 forms a rotary pair connection with the support shaft 10 through a planet carrier bearing 7.

[0041] For the technical solution of this embodiment, both the first vibration damping structure 401 and the third vibration damping structure 403 are set as rubber elements with viscoelasticity;

[0042] The second damping structure 402 includes rubber elements and in-wheel dampers 22 disposed between the motor housing 2 and the support shaft 10. The rubber elements are all axisymmetric elements, and the stiffness characteristics of each rubber element are optimized and configured based on the vibration mode characteristics of the motor-suspension coupling system;

[0043] The in-wheel damper 22 adopts a single-tube integrated passive damping structure with upper and lower mirror symmetry. The in-wheel damper 22 includes two sets of coaxially nested hydraulic damping units and helical spring dampers. The hydraulic damping unit is a single-tube passive hydraulic damper, and a displacement sensor is provided at the end of the outer shell of the helical spring damper for real-time detection of the relative displacement between the support shaft 10 and the motor housing 2.

[0044] Regarding the technical solution of this embodiment, a steering servo motor 16 is meshingly installed on the knuckle 21. The steering servo motor 16 is rigidly connected to the upper cross arm 18 through a steering motor support 17. The steering servo motor 16 includes a worm and worm gear reducer with a self-locking function. Specifically, the steering servo motor 16 serves as a power source, and its housing is rigidly connected to the steering motor bracket through multiple groups of high-strength bolts 5. A high-load-capacity angular contact thrust bearing is integrated inside the steering motor bracket. An involute spline structure is provided at the end of the output shaft of the steering servo motor 16, forming a clearance-free torque transmission assembly with the spline groove corresponding to the inner hole of the knuckle 21; the steering motor bracket and the outer ring of the thrust bearing are fixed by a precision interference fit to construct a stable axial load transmission path; the rotation axis of the output shaft of the steering servo motor 16 accurately passes through the rotation center of the knuckle 21 and the ball joint center of the lower control arm in the spatial layout, forming multiple geometric collinear constraints to effectively control the motion deviation of the knuckle 21 when rotating around the axis.

[0045] Regarding the technical solution of this embodiment, the suspension system further includes an air spring and a magnetorheological damper 19. The air spring and the magnetorheological damper 19 are arranged in parallel to support active adjustment of the stiffness and damping coefficient. The working cylinder of the magnetorheological damper 19 is filled with magnetorheological fluid, and a step change in the damping force is realized through an electromagnetic coil.

[0046] Regarding the technical solution of this embodiment, the upper end of the knuckle 21 is connected to the left end of the upper cross arm 18, and the lower end is connected to the left end of the lower cross arm 20, and two rotating pairs are formed. The right ends of the upper and lower cross arms 20 are both connected to the vehicle frame through rotating pairs;

[0047] The lower end of the magnetorheological damper 19 forms a rotating pair with the lower cross arm 20, and the upper end is connected to the vehicle frame through a ball joint.

[0048] The working principle of the present invention is as follows: When the road surface excitation is transmitted to the vehicle body through the tire and the suspension system, the three-stage damping structure built in the system works together:

[0049] The first vibration reduction structure 401 uses a high-rigidity rubber element to connect the planetary carrier 6 and the wheel hub 8 at the output end of the reduction system, thereby blocking the interference of the vertical vibration of the wheel 1 on the dynamic balance of the motor rotor 15, ensuring the uniformity of the air gap magnetic field of the motor and extending the service life of the motor;

[0050] The second vibration reduction structure 402 includes a viscoelastic rubber element and an in-wheel shock absorber 22. The rubber element connects the support shaft 10 and the motor stator 3, and uses the internal friction damping of the viscoelastic material to effectively absorb the medium-frequency vibration energy caused by the motor torque fluctuation, blocking the transmission path of the medium-frequency vibration to the suspension system; the passive in-wheel shock absorber 22 adopts a preset nonlinear damping curve design, and forms a fixed damping characteristic between the motor housing 2 and the support shaft 10 through mechanical structure parameter matching. This part dynamically decouples the motor mass from the unsprung mass and uses it as a dynamic vibration absorber to reduce vibration;

[0051] The third vibration reduction structure 403 is arranged at the connection between the double wishbone of the suspension and the steering knuckle 21, and is provided with a long-stroke rubber bushing to absorb the low-frequency vibration caused by the undulation of the road surface by using its large deformation capacity. At the same time, the magnetorheological shock absorber 19 and the air spring are arranged in parallel on the lower cross arm 20 of the suspension, and the damping and elastic parameters are adjusted in real time through the coupling effect of the electrorheological fluid and the gas pressure. This part starts from the angle of transmission of the vibration of the wheel 1 to the vehicle body, and reduces the vertical vibration of the vehicle body;

[0052] This integrated design not only improves the dynamic characteristics of the corner module system and the entire vehicle, but also greatly reduces the complexity of manufacturing and assembly through a modular architecture, providing an innovative technical solution for the chassis system of new energy vehicles.

[0053] Next, the technical solution of the present invention is further described in conjunction with specific embodiments:

[0054] See also Figure 2 (a) In the actual operation of the vehicle, the corner module vibration reduction system achieves vertical dynamics optimization through a three-level coordinated vibration reduction mechanism. Figure 2 (b) shows the correspondence between the three-stage vibration reduction unit in the structural diagram and the 1 / 4 vehicle model, and the three-stage vibration reduction unit is represented by I, II, and III respectively.

[0055] When the road excitation is transmitted to the corner module through the tire, each vibration reduction unit responds in a coordinated manner according to the vibration characteristics. The first vibration reduction structure 401 between the planetary carrier 6 on the wheel hub 8 motor and the wheel hub 8 takes the lead in taking effect and quickly absorbing the high-frequency vibration energy transmitted by the tire. While ensuring the power transmission efficiency, the first vibration reduction structure 401 significantly reduces the vibration amplitude of the motor rotor 15, effectively maintains the stability of the internal magnetic field of the motor, and avoids torque fluctuations caused by high-frequency disturbances. The second vibration reduction structure 402 between the support shaft 10 and the motor stator 3 forms a composite vibration reduction system with the in-wheel vibration absorber 22. The second vibration reduction structure 402 suppresses the medium-frequency vibration through viscoelasticity, while the passive in-wheel vibration absorber 22 is based on a preset nonlinear damping curve. The mechanical structure parameters are matched to form a fixed damping characteristic between the support shaft 10 and the wheel hub 8 motor housing 2. The two work together to produce a mechanical decoupling effect, which not only blocks the transmission path of vibration to the suspension system, but also enables the wheel hub 8 motor mass to play the role of a dynamic vibration absorber through the resonance tuning of the mass-spring-damping system; when encountering severe impact, the upper and lower cross arms 20 suspension system play a leading role, and the parallel combination of the magnetorheological shock absorber 19 and the air spring adjusts the stiffness and damping parameters in real time, and cooperates with the third vibration reduction structure 403 at the connection of the steering knuckle 21 to form a multi-stage buffer mechanism, ultimately achieving the synchronous optimization of the sprung mass vibration, the wheel hub 8 motor impact and the tire dynamic load, and comprehensively improving the vehicle's driving smoothness and handling stability.

[0056] The vertical dynamic performance of the corner module is verified by a 1 / 4 vehicle model. In the figure, m1, m2, and m4 are the wheel mass, sprung mass, and steering motor mass, respectively. 31 is the mass of the support shaft 10 and the steering knuckle 21, m 32 is the mass of the hub motor stator 3, rotor 15, planetary gear reduction assembly 13 and motor housing 2, m4 is the mass of the suspension arm and the steering servo motor 16 mounted on the upper cross arm 18, k1 and k2 are the spring stiffness of the tire and suspension, and the stiffness and damping of the viscoelastic rubber element are represented by k 41 , k 42 , k 43 and c 41 、c 42 、c 43 Indicates that c w ,c s are the output damping of the in-wheel shock absorber 22 and the electromagnetic semi-active shock absorber, respectively. Through the transfer function of the sprung mass acceleration and the tire dynamic load, its amplitude-frequency characteristic H can be obtained. a and H t .

[0057] Depend on Figure 3It can be seen that, under the same structural parameters, compared with the existing conventional corner modules, except that in the low-frequency band where f < f0 = 0.108 Hz, the amplitude of the sprung mass acceleration of the corner module is slightly larger, in other frequency bands, the vibration amplitude of the corner module has a large decrease, and the maximum amplitude reduction is close to 50.3 dB. In the human sensitive region of 4 - 8 Hz, the decrease is more obvious. The dynamic load of the tire can be analyzed by the amplitude-frequency characteristics of (y1 - y0) / y0, where y1 is the tire displacement and y0 is the road surface excitation. From Figure 4 It can be seen that the amplitude curve of the dynamic load of the tire of the corner module changes relatively smoothly and is below that of the conventional corner module in all cases, with a large decrease. The above dynamic verification shows that by decoupling the dynamic coupling of the motor mass and the unsprung mass and combining the hierarchical vibration damping strategy, the present invention successfully transforms the negative impact of the unsprung mass of the new drive and steering system into the advantage of dynamic vibration absorption.

[0058] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0059] For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. When an element is referred to as being "assembled on", "mounted on", "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation.

[0060] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

[0061] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

Claims

1. An electric drive power wheel system based on multi-stage vibration damping design, which is applied to the field of driving of an electric vehicle wheel (1), is characterized in that, It includes a hub (8) installed on a wheel (1). A support shaft (10) is rotatably connected to the central position of the hub (8). An outer surface of the support shaft (10) is fixedly installed with a motor housing (2). A stator (3) and a planetary gear reduction assembly (13) are installed inside the motor housing (2). And a first vibration damping structure (401) is installed between the planetary gear reduction assembly (13) and the hub (8) for attenuating high-frequency vibrations of the motor. A second vibration damping structure (402) is installed between the motor housing (2) and the support shaft (10) for blocking the transmission of medium-frequency vibrations to the suspension system. The suspension system includes a steering knuckle (21). The upper and lower ends of the steering knuckle (21) are respectively hinged to an upper cross arm (18) and a lower cross arm (20). The support shaft (10) passes through a central hole of the steering knuckle (21). And a third vibration damping structure (403) is provided between the steering knuckle (21) and the support shaft (10) for absorbing low-frequency vibrations caused by road surface undulations.

2. The electric drive power wheel system based on multi-stage vibration damping design according to claim 1, characterized in that: The hub (8) and the support shaft (10) are rotatably connected through a hub bearing (9).

3. The electric drive power wheel system based on multi-stage vibration damping design according to claim 2, wherein: The stator (3) and the motor housing (2) are both fixedly connected to the support shaft (10). An inside of the motor housing (2) is rotatably connected to a motor rotor hub (14). The motor rotor hub (14) and the support shaft (10) are rotatably connected through a motor rotor hub (14) bearing (11).

4. A kind of electric drive power wheel system based on multi-stage vibration reduction design according to claim 3, characterized in that: A rotor (15) is installed on a side wall of the motor rotor hub (14). And the planetary gear reduction assembly (13) is also installed on the motor rotor hub (14).

5. A kind of electric drive power wheel system based on multi-stage vibration reduction design according to claim 4, characterized in that: The planetary gear reduction assembly (13) includes a sun gear, planet gears, a planet carrier (6) and a ring gear. The sun gear is connected to the motor rotor hub (14). The ring gear is fixedly connected to the motor housing (2) through a flange. The planet gears and the planet carrier (6) are connected through a planet pin (12). The planet carrier (6) is connected to the hub (8) through a connecting bolt (5) and the first vibration damping structure (401). The planet carrier (6) forms a rotary pair connection with the support shaft (10) through a planet carrier bearing (7).

6. The electro-driven power wheel system based on multi-stage vibration damping design according to claim 5, characterized in that: Both the first vibration damping structure (401) and the third vibration damping structure (403) are set as rubber elements with viscoelasticity. The second vibration damping structure (402) includes a rubber element and an in-wheel shock absorber (22) arranged between the motor housing (2) and the support shaft (10). The in-wheel shock absorber (22) adopts a single-tube integrated passive vibration damping structure arranged symmetrically up and down. The in-wheel shock absorber (22) includes two sets of coaxially nested hydraulic damping units and a helical spring shock absorber. The hydraulic damping unit is a single-tube passive hydraulic damper. And a displacement sensor is provided at an end of the helical spring shock absorber housing for real-time detection of the relative displacement between the support shaft (10) and the motor housing (2).

7. The electric drive power wheel system based on multi-stage vibration damping design according to claim 6, characterized in that: A steering servo motor (16) is meshingly installed on the steering knuckle (21). The steering servo motor (16) is rigidly connected to the upper cross arm (18) through a steering motor support (17).

8. A kind of electric drive power wheel system based on multi-stage vibration damping design according to claim 6, characterized in that: The steering servo motor (16) includes a worm and worm gear reducer with a self-locking function. The output shaft of the steering servo motor (16) is meshed with the inner hole of the knuckle (21) through an involute spline, and the axis of the output shaft of the steering servo motor (16) passes through the center of rotation of the knuckle (21) and the center of the ball joint of the lower cross arm (20).

9. The electro-driven power wheel system based on multi-stage vibration damping design according to claim 8, characterized in that: The suspension system further includes an air spring and a magnetorheological damper (19). The air spring and the magnetorheological damper (19) are arranged in parallel. The working cylinder of the magnetorheological damper (19) is filled with magnetorheological fluid, and the step change of the damping force is realized through an electromagnetic coil.

10. A kind of electric drive power wheel system based on multi-stage vibration reduction design according to claim 9, characterized in that: The upper end of the knuckle (21) is connected to the left end of the upper cross arm (18), and the lower end is connected to the left end of the lower cross arm (20), and two rotating pairs are formed. The right ends of the upper and lower cross arms (20) are both connected to the vehicle frame through rotating pairs; The lower end of the magnetorheological damper (19) forms a rotating pair with the lower cross arm (20), and the upper end is connected to the vehicle frame through a ball joint.

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