Wheel assembly with mutually redundant hub and steering motors and control method thereof

Abstract

A wheel assembly is provided with mutually redundant hub and steering motors. The wheel assembly includes a wheel 1, a hub motor 2, a steering motor 3, a reducer 5 and a suspension system. Hub motor 2

Description

[0001] The present disclosure relates to the technical field of electric wheels, and in particular, to a wheel assembly with mutually redundant hub and steering motors and a control method thereof. BACKGROUND

[0002] The electric wheel assembly is one of the core devices of the electric vehicle. The electric wheel assembly combines the hub motor and transmission, braking, and steering devices, which simplifies the transmission, clutch, transmission shaft, and differential in the traditional automobile, and directly transfers the driving force to the wheel, making the vehicle space utilization rate and transmission efficiency greatly improved. However, the technical difficulty of the electric wheel assembly lies in the narrow installation space, and the installation of components requires a large amount of time. In particular, most of the current electric wheel assemblies arrange the steering motor near the support arm of the suspension, occupying a large amount of installation space, which is not conducive to the integration of the electric wheel assembly.

[0003] In addition, in the existing electric wheel assembly, the wheel rotation and steering are respectively driven by a hub motor and a steering motor. If the motor fails, it will bring serious consequences to the safety of the driver. If the spare motor is simply added for both the hub motor and the steering motor, a lot of installation space is needed for layout, which is contrary to the design concept of integrated and compact electric wheel assembly. SUMMARY

[0004] In view of the above problems, the present disclosure provides a wheel assembly with mutually redundant hub and steering motors and further provides a control method thereof.

[0005] The present disclosure is implemented by the following technical solutions:

[0006] The present disclosure provides a wheel assembly with mutually redundant hub and steering motors, including a wheel, a hub motor, a steering motor, a reducer and a suspension system. The hub motor is in transmission connection with a hub of the wheel to drive the wheel to rotate. The steering motor is in transmission connection with the suspension system through the reducer to drive the wheel for steering. The hub motor and the steering motor are arranged in a hub cavity of the wheel coaxially side by side. The reducer is a right-angle reducer to change a direction of power output by the steering motor by 90 degrees and transmit the power to the suspension system.

[0007] Preferably, the wheel assembly further includes a first electric control clutch device, a second electric control clutch device and a third electric control clutch device. The hub of the wheel includes a rotating shaft. The hub motor includes a first motor shaft outputting a torque. The steering motor includes a second motor shaft outputting a torque. The reducer includes a power input shaft. The rotating shaft, the first motor shaft, the second motor shaft and the power input shaft are arranged coaxially in sequence. The rotating shaft and a first end of the first motor shaft are in separable transmission connection through the first electric control clutch device. A second end of the first motor shaft and a first end of the second motor shaft are in separable transmission connection through the second electric control clutch device. A second end of the second motor shaft and the power input shaft are in separable transmission connection through the third electric control clutch device.

[0008] Preferably, the wheel assembly further includes a motor housing and a brake. Both the hub motor and the steering motor are accommodated in the motor housing, and the brake is arranged between the motor housing and the hub of the wheel.

[0009] Preferably, the hub motor and the steering motor have an equivalent outer diameter, and the motor housing is of a cylindrical structure.

[0010] Preferably, the reducer includes a box, and the box is fixed on the motor housing.

[0011] Preferably, the suspension system includes an upper swing arm, an upper support arm, a lower swing arm and a lower support arm. The upper swing arm and the lower swing arm are arranged up and down in a vertical direction. The upper swing arm includes one end fixedly connected with a frame and the other end connected with the upper support arm through a ball head. The upper support arm is further fixedly connected with the motor housing. The lower swing arm includes one end fixedly connected with the frame and the other end hinged with the lower support arm by a hinged shaft in a horizontal direction. The lower support arm and an output shaft of the reducer are connected through a shaft pin. A thrust bearing is arranged between the lower support arm and the output shaft of the reducer.

[0012] The present disclosure further provides a control method of a wheel assembly with mutually redundant hub and steering motors, adopting the wheel assembly with mutually redundant hub and steering motors as described above. The control method includes: determining whether the hub motor and the steering motor work normally, and if both the hub motor and the steering motor work normally, maintaining the normally closed first electric control clutch device and the third electric control clutch device in an engaged state and the normally open second electric control clutch device in a disengaged state, driving, by the hub motor, the wheel to rotate, and driving, by the steering motor, the wheel for steering; if the hub motor fails and the steering motor works normally, controlling the normally closed third electric control clutch device to be switched to a disengaged state, the normally open second electric control clutch device to be switched to an engaged state, and the first electric control clutch device to be kept in the engaged state continuously, and temporarily driving, by the steering motor, the wheel to rotate; and if the steering motor fails and the hub motor works normally, controlling the normally closed first electric control clutch device to be switched to a disengaged state, the normally open second electric control clutch device to be switched to the engaged state, and the third electric control clutch device to be kept in the engaged state continuously, and temporarily driving, by the hub motor, the wheel for steering.

[0013] Preferably, the control method includes: if the hub motor fails and the steering motor works normally, and a failure occurs in a rear wheel, determining whether the rear wheel is in a steering state, and if the wheel is in the steering state, controlling the steering motor to drive the wheel to be aligned, controlling the normally closed third electric control clutch device to be switched to the disengaged state, the normally open second electric control clutch device to be switched to the engaged state, and the first electric control clutch device to be kept in the engaged state continuously, and temporarily driving, by the steering motor, the wheel to rotate; and if the wheel is not in the steering state, directly controlling the normally closed third electric control clutch device to be switched to the disengaged state, the normally open second electric control clutch device to be switched to the engaged state, and the first electric control clutch device to be kept in the engaged state continuously, and temporarily driving, by the steering motor, the wheel to rotate.

[0014] The present disclosure has the following beneficial effects: the hub motor and the steering motor are arranged in the hub cavity of the wheel coaxially side by side, such that an internal space of the hub cavity is effectively utilized, arrangement of the hub motor and the steering motor is very compact, and space occupation of the wheel assembly is reduced. Through arranging the first electric control clutch device, the second electric control clutch device and the third electric control clutch device, the hub motor and the steering motor can be mutually redundant backup while keeping the compact layout of the hub motor and the steering motor, which greatly improves the safety of vehicle driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is a schematic diagram of a wheel assembly with mutually redundant hub and steering motors in an embodiment; and

[0016] FIG. 2 is a logical table diagram of mutual redundancy of the hub and steering motors in the embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] To further illustrate the embodiments, the present disclosure provides accompanying drawings. The accompanying drawings, as a part of the present disclosure, are mainly used to illustrate the embodiments, and can explain the operating principles of the embodiments with reference to the related descriptions in this specification. With reference to such content, those of ordinary skill in the art can understand other possible implementations and the advantages of the present disclosure. Components in the drawings are not drawn to scale, and similar reference numerals are usually used to represent similar components.

[0018] The present disclosure will be further described below with reference to the accompanying drawing and specific implementations.

[0019] With reference to FIG. 1, as a preferred embodiment of the present disclosure, a wheel assembly with mutually redundant hub and steering motors is provided, including a wheel 1, a hub motor 2 for driving the wheel 1 to rotate, and a steering motor 3 for driving the wheel 1 for steering. The hub motor 2 and the steering motor 3 are arranged in a hub cavity 15 of the wheel 1 coaxially side by side. An output shaft of the steering motor 3 is in transmission connection with a reducer 5. The reducer 5 is a right-angle reducer, that is, an input shaft and an output shaft of the reducer 5 are distributed at 90 degrees, such that the reducer 5 can increase and decelerate the torque output by the steering motor 3, and change a direction of power output by the steering motor 3 by 90 degrees and transmit the power to the suspension system, so as to realize the steering function of the wheel 1. In the present embodiment, the hub motor 2 and the steering motor 3 are arranged in the hub cavity 15 of the wheel 1 coaxially side by side, such that an internal space of the hub cavity 15 is effectively utilized, arrangement of the hub motor 2 and the steering motor 3 is very compact, and space occupation of the wheel assembly is reduced, facilitating the manufacturing, assembly and transportation of the wheel assembly. Since the hub motor 2 and the steering motor 3 are arranged side by side, the radial spaces of the two do not interfere with each other. The motor stator and rotor of the hub motor 2 and steering motor 3 can be designed with larger diameter specifications, which can improve the output torque of the hub motor 2 and the steering motor 3. In the present embodiment, the hub motor 2 and the steering motor 3 have an equivalent outer diameter, which ensures that the hub motor 2 and steering motor 3 have a larger output torque, and makes their installation and coordination easier.

[0020] The wheel assembly of the present embodiment further includes a first electric control clutch device 16, a second electric control clutch device 6 and a third electric control clutch device 7. The hub of the wheel 1 includes a rotating shaft 101. The hub motor 2 includes a first motor shaft 201 outputting a torque. The steering motor 3 includes a second motor shaft 301 outputting a torque. The reducer 5 includes a power input shaft 501. The rotating shaft 101, the first motor shaft 201, the second motor shaft 301 and the power input shaft 501 are arranged coaxially in sequence. The rotating shaft 101 and a first end of the first motor shaft 201 are in separable transmission connection through the first electric control clutch device 16 (The separable transmission connection, that is, the first electric control clutch device 16 has two states of "engagement" and "disengagement" to control the connection state of the first motor shaft 201 and the rotating shaft 101. The first electric control clutch device 16 can be engaged, such that the rotating shaft 101 and the first motor shaft 201 are in transmission connection so as to transmit torque, and it can also be disengaged to release the transmission connection between the rotating shaft 101 and the first motor shaft 201. The functions of the second electric control clutch device 6 and the third electric control clutch device 7 below are similar, so the description will not be repeated). A second end of the first motor shaft 201 and a first end of the second motor shaft 301 are in separable transmission connection through the second electric control clutch device 6. A second end of the second motor shaft 301 and the power input shaft 501 are in separable transmission connection through the third electric control clutch device 7. Under the normal running of the vehicle, the first electric control clutch device 16 and the third electric control clutch device 7 are normally closed (that is, under the normal running condition of the vehicle, maintain in the engaged state), and the second electric control clutch device 6 is normally open (that is, under the normal running condition of the vehicle, maintain in the disengaged state). At this time, the steering motor 3 and the hub motor 2 do not interfere with each other. The hub motor 2 drives to the wheel 1, the steering motor 3 drives to the reducer 5 and then to the suspension system, and the hub motor 2 and the steering motor 3 respectively complete rotation and steering of the wheel 1. But if one of the steering motor 3 and the hub motor 2 breaks down suddenly, the other motor can provide emergency power support and temporarily undertake the work of the failed motor, that is, the steering motor 3 and the hub motor 2 are mutually redundant. Specifically:

[0021] 1. If the hub motor 2 fails and the steering motor 3 works normally, an electric control system controls the third electric control clutch device 7 to be switched to the disengaged state, the second electric control clutch device 6 to be switched to the engaged state, and the first electric control clutch device 16 to be kept in the engaged state continuously without switching. At this time, the power of the second motor shaft 301 is reversely transmitted to the rotating shaft 101, and the steering motor 3 drives the wheel 1 to rotate.

[0022] 2. If the steering motor 3 fails and the hub motor 2 works normally, the electric control system controls the first electric control clutch device 16 to be switched to the disengaged state, the second electric control clutch device 6 to be switched to the engaged state, and the third electric control clutch device 7 to be kept in the engaged state continuously without switching. At this time, the power of the first motor shaft 201 is transmitted to the second motor shaft 301 and finally to the power input shaft 501.

[0023] As a special case, if the hub motor 2 of the rear wheel in the steering state fails, the steering motor 3 controlling the rear wheel first aligns the rear wheel, and reversely transmits the power of the second motor shaft 301 to the rotating shaft 101 by switching the state of the electric control clutch device to drive the wheel 1 to rotate. At this time, the rear wheel is aligned. The rear wheel still has forward power under the support of the steering motor 3. The steering function of the front wheel is normal, and can still realize the steering of the vehicle. With this preferred design, the vehicle can continue to drive in a straight line or turn after turning a comer, leaving the driver with a longer reaction time.

[0024] In the present embodiment, whether the hub motor 2 and the steering motor 3 fail can be determined by arranging a speed sensor, and whether the wheel is in the steering state can be determined by arranging an angle sensor.

[0025] FIG. 2 is a logical table diagram of mutual redundancy of the steering motor 3 and the hub motor 2, which can be used for reference.

[0026] In the present embodiment, through the above arrangement, the hub motor 2 and the steering motor 3 can be mutually safe and redundant backup under the condition of very compact layout. That is, the hub motor 2 is used for driving and the steering motor 3 is used for steering under normal circumstances. However, in the specific condition of motor failure, the mutual assistance function of the hub motor 2 and the steering motor 3 can be realized by regulating the first electric control clutch device 16, the second electric control clutch device 6 and the third electric control clutch device 7. When one of the motors fails, the running state of the vehicle is temporarily maintained, giving the driver sufficient time to judge and inspect the vehicle condition, which greatly improves the safety of vehicle driving.

[0027] The first electric control clutch device 16, the second electric control clutch device 6 and the third electric control clutch device 7 adopt the automobile clutch as the specific implementation solution in the present embodiment.

[0028] In the present embodiment, the wheel assembly further includes a motor housing 13 and a brake 4. Both the hub motor 2 and the steering motor 3 are accommodated in the motor housing 13, and the brake 4 is arranged between the motor housing 13 and the hub of the wheel 1, that is, there is a mounting space for the brake 4 between the motor housing 13 and the wheel 1. In the present embodiment, the hub motor 2 and the steering motor 3 have an equivalent outer diameter, so the motor housing 13 is of a cylindrical structure, which makes the manufacturing and assembly of the motor housing 13 more convenient. The mounting space between the motor housing 13 and the hub of the wheel 1 includes a gap between the motor housing 13 in the axial direction and the hub which can be used to install the brake disc and brake caliper, and a gap between the motor housing 13 in the radial direction and the hub which can be used for the brake tubing to pass through.

[0029] The reducer 5 is an angular bevel gear reducer, which changes a direction of power by 90 degrees through a pair of meshing bevel gears, with low cost and reliable structure. The reducer 5 includes a box 14, and the box 14 is fixed on the motor housing 13, so as to facilitate the manufacturing and installation of the wheel assembly as a whole.

[0030] The suspension system includes an upper swing arm 8, an upper support arm 9, a lower swing arm 11 and a lower support arm 10. The upper swing arm 8 and the lower swing arm 9 are arranged up and down in a vertical direction. The upper swing arm 8 includes one end fixedly connected with a frame and the other end connected with the upper support arm 9 through a ball head. The upper support arm 9 is further fixedly connected with the motor housing. The lower swing arm 11 includes one end fixedly connected with the frame and the other end hinged with the lower support arm 10 by a hinged shaft in a horizontal direction. The lower support arm 10 and an output shaft of the reducer 5 are connected through a shaft pin. A thrust bearing 12 is arranged between the lower support arm 10 and the output shaft of the reducer 5. When the steering motor 3 sends out the steering torque, after decelerating and increasing the torque and changing the direction through the reducer 5, the torque is transmitted to the lower support arm 10 through the output shaft of the reducer 5 and the pin connection of the lower support arm 10. However, because the lower support arm 10 cannot rotate with the vertical direction as the axis, according to Newton's third law, the reaction torque of the steering torque rotates the wheel to achieve steering by wire. The hinge of the lower swing arm 11 and the lower support arm 10 in the horizontal direction can endow the wheel with the freedom of jumping in the vertical direction, such that when the wheel needs to jump through the uneven road, it has a certain jumping allowance. The thrust bearing 12 has excellent bearing capacity for axial load, which can prevent excessive load from acting on the lower swing arm 11 and the lower support arm 10 when the wheel jumps, and improve the structural strength.

[0031] Based on the above wheel assembly with mutually redundant hub and steering motors, the present embodiment further provides a control method of the wheel assembly with mutually redundant hub and steering motors. The control method includes the following steps. Whether the hub motor 2 and the steering motor 3 work normally is determined, and if both the hub motor 2 and the steering motor 3 work normally, the normally closed first electric control clutch device 16 and the third electric control clutch device 7 are maintained in an engaged state and the normally open second electric control clutch device 6 is maintained in a disengaged state, the hub motor 2 drives the wheel 1 to rotate, and the steering motor 3 drives the wheel 1 for steering. If the hub motor 2 fails and the steering motor 3 works normally, the normally closed third electric control clutch device 7 is controlled to be switched to a disengaged state, the normally open second electric control clutch device 6 is controlled to be switched to an engaged state, and the first electric control clutch device 16 is controlled to be kept in the engaged state continuously, and the steering motor 3 temporarily drives the wheel 1 to rotate. If the steering motor 3 fails and the hub motor 2 works normally, the normally closed first electric control clutch device 16 is controlled to be switched to a disengaged state, the normally open second electric control clutch device 6 is controlled to be switched to the engaged state, and the third electric control clutch device 7 is controlled to be kept in the engaged state continuously, and the hub motor 2 temporarily drives the wheel 1 for steering.

[0032] If the hub motor 2 fails and the steering motor 3 works normally, and a failure occurs in a rear wheel, whether the rear wheel 1 is in a steering state is determined, and if the wheel 1 is in the steering state, the steering motor 3 is controlled to drive the wheel 1 to be aligned, the normally closed third electric control clutch device 7 is controlled to be switched to the disengaged state, the normally open second electric control clutch device 6 is controlled to be switched to the engaged state, and the first electric control clutch device 16 is controlled to be kept in the engaged state continuously, and the steering motor 3 drives the wheel 1 to rotate. If the wheel 1 is not in the steering state, the normally closed third electric control clutch device 7 is directly controlled to be switched to the disengaged state, the normally open second electric control clutch device 6 is controlled to be switched to the engaged state, and the first electric control clutch device 16 is controlled to be kept in the engaged state continuously, and the steering motor 3 drives the wheel 1 to rotate.

[0033] Through the above control method, the hub motor 2 and the steering motor 3 can be mutually safe and redundant backup. That is, the hub motor 2 is used for driving and the steering motor 3 is used for steering under normal circumstances. However, in case of failure of the hub motor 2, the mutual assistance function of the hub motor 2 and the steering motor 3 can be realized by regulating the first clutch device 16 and the second clutch device 6. When one of the motors fails, the running state of the vehicle is temporarily maintained, giving the driver sufficient time to judge and inspect the vehicle condition, which greatly improves the safety of vehicle driving.

[0034] Although the present disclosure is specifically illustrated and described in combination with preferred implementation solutions, those skilled in the art should understand that various changes made to the present disclosure in terms of forms and details without departing from the spirit and scope of the present disclosure defined in the appended claims shall fall within the protection scope of the present disclosure.

Claims

1. Awheel assembly with mutually redundant hub and steering motors, comprising a wheel, a hub motor, a steering motor, a reducer and a suspension system, wherein the hub motor is in transmission connection with a hub of the wheel to drive the wheel to rotate, the steering motor is in transmission connection with the suspension system through the reducer to drive the wheel for steering, the hub motor and the steering motor are arranged in a hub cavity of the wheel coaxially side by side, and the reducer is a right-angle reducer to change a direction of power output by the steering motor by 90 degrees and transmit the power to the suspension system.

2. The wheel assembly with mutually redundant hub and steering motors according to claim 1, further comprising a first electric control clutch device, a second electric control clutch device and a third electric control clutch device, wherein the hub of the wheel comprises a rotating shaft, the hub motor comprises a first motor shaft outputting a torque, the steering motor comprises a second motor shaft outputting a torque, the reducer comprises a power input shaft, the rotating shaft, the first motor shaft, the second motor shaft and the power input shaft are arranged coaxially in sequence, the rotating shaft and a first end of the first motor shaft are in separable transmission connection through the first electric control clutch device, a second end of the first motor shaft and a first end of the second motor shaft are in separable transmission connection through the second electric control clutch device, and a second end of the second motor shaft and the power input shaft are in separable transmission connection through the third electric control clutch device.

3. The wheel assembly with mutually redundant hub and steering motors according to claim 1, further comprising a motor housing and a brake, wherein both the hub motor and the steering motor are accommodated in the motor housing, and the brake is arranged between the motor housing and the hub of the wheel.

4. The wheel assembly with mutually redundant hub and steering motors according to claim 3, wherein the hub motor and the steering motor have an equivalent outer diameter, and the motor housing is of a cylindrical structure.

5. The wheel assembly with mutually redundant hub and steering motors according to claim 3, wherein the reducer comprises a box, and the box is fixed on the motor housing.

6. The wheel assembly with mutually redundant hub and steering motors according to claim 5, wherein the suspension system comprises an upper swing arm, an upper support arm, a lower swing arm and a lower support arm, the upper swing arm and the lower swing arm are arranged up and down in a vertical direction, the upper swing arm comprises one end fixedly connected with a frame and the other end connected with the upper support arm through a ball head, and the upper support arm is further fixedly connected with the motor housing; and the lower swing arm comprises one end fixedly connected with the frame and the other end hinged with the lower support arm by a hinged shaft in a horizontal direction, the lower support arm and an output shaft of the reducer are connected through a shaft pin, and a thrust bearing is arranged between the lower support arm and the output shaft of the reducer.

7. A control method of a wheel assembly with mutually redundant hub and steering motors, adopting the wheel assembly with mutually redundant hub and steering motors according to any of claims 1 to 6, and comprising: determining whether the hub motor and the steering motor work normally, and if both the hub motor and the steering motor work normally, maintaining the normally closed first electric control clutch device and the third electric control clutch device in an engaged state and the normally open second electric control clutch device in a disengaged state, driving, by the hub motor, the wheel to rotate, and driving, by the steering motor, the wheel for steering; if the hub motor fails and the steering motor works normally, controlling the normally closed third electric control clutch device to be switched to a disengaged state, the normally open second electric control clutch device to be switched to an engaged state, and the first electric control clutch device to be kept in the engaged state continuously, and temporarily driving, by the steering motor, the wheel to rotate; and if the steering motor fails and the hub motor works normally, controlling the normally closed first electric control clutch device to be switched to a disengaged state, the normally open second electric control clutch device to be switched to the engaged state, and the third electric control clutch device to be kept in the engaged state continuously, and temporarily driving, by the hub motor, the wheel for steering.

8. The control method of a wheel assembly with mutually redundant hub and steering motors according to claim 7, comprising: if the hub motor fails and the steering motor works normally, and a failure occurs in a rear wheel, determining whether the rear wheel is in a steering state, and if the wheel is in the steering state, controlling the steering motor to drive the wheel to be aligned, controlling the normally closed third electric control clutch device to be switched to the disengaged state, the normally open second electric control clutch device to be switched to the engaged state, and the first electric control clutch device to be kept in the engaged statecontinuously, and temporarily driving, by the steering motor, the wheel to rotate; and if the wheel is not in the steering state, directly controlling the normally closed third electric control clutch device to be switched to the disengaged state, the normally open second electric control clutch device to be switched to the engaged state, and the first electric control clutch device to be kept in the engaged state continuously, and temporarily driving, by the steering motor, the wheel to rotate.

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