Wheel assembly with redundant hub motor and steering motor and control method thereof

Abstract

The present invention relates to a wheel assembly in which an in-wheel motor and a steering motor are redundant, and a control method thereof. The wheel assembly includes a wheel, an in-wheel motor, a steering motor, a speed reducer, and a suspension system. The in-wheel motor is drivingly connected to the wheel hub to drive the wheel to rotate, and the steering motor is drivingly connected to the suspension system via the speed reducer to drive the wheel to steer. The in-wheel motor and the steering motor are coaxially arranged side by side within the wheel hub cavity. The speed reducer is a right-angle speed reducer that redirects the power output by the steering motor 90 degrees before transmitting it to the suspension system. The present invention coaxially arranges the in-wheel motor and the steering motor side by side within the wheel hub cavity, effectively utilizing the internal space of the wheel hub cavity, making the arrangement of the in-wheel motor and the steering motor very compact and reducing the space occupied by the wheel assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of electric wheels, and in particular to a wheel assembly in which a hub motor and a steering motor are redundant with each other. Background Art

[0002] The electric wheel assembly is one of the core components of an electric vehicle. It integrates the in-wheel motor with the transmission, braking, and steering systems, simplifying the transmission, clutch, drive shaft, differential, and other components found in traditional vehicles. This allows the drive force to be directly transmitted to the wheels, significantly improving the vehicle's space utilization and transmission efficiency. However, the technical difficulty of the electric wheel assembly lies in the limited installation space and the significant time required to install the components. In particular, most current electric wheel assemblies place the steering motor near the suspension's support arm, occupying a significant amount of installation space and hindering the integration of the electric wheel assembly.

[0003] Furthermore, in existing electric wheel assemblies, wheel rotation and steering are driven by a single in-wheel motor and a single steering motor, respectively. A motor failure could have serious consequences for driver safety. Simply adding backup motors for both the in-wheel motor and the steering motor would require significant installation space, contradicting the integrated and compact design philosophy of electric wheel assemblies. Summary of the Invention

[0004] Therefore, in order to solve the above problems, the present invention proposes a wheel assembly in which a hub motor and a steering motor are redundant with each other, and based on the wheel assembly, also proposes a control method thereof.

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

[0006] The present invention proposes a wheel assembly in which a hub motor and a steering motor are redundant with each other, including a wheel, a hub motor, a steering motor, a reducer and a suspension system. The hub motor is connected to the hub of the wheel to drive the wheel to rotate, and the steering motor is connected to the suspension system through the reducer to drive the wheel to steer. The hub motor and the steering motor are coaxially arranged side by side in the hub cavity of the wheel. The reducer is a right-angle reducer to change the direction of the power output by the steering motor by 90 degrees and then transmit it to the suspension system.

[0007] Among them, it is preferred that it also includes a first electronically controlled clutch device, a second electronically controlled clutch device and a third electronically controlled clutch device, the wheel hub includes a rotating shaft, the hub motor includes a first motor shaft that outputs its torque, the steering motor includes a second motor shaft that outputs its 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 coaxially arranged in sequence, the rotating shaft and the first end of the first motor shaft are detachably connected by transmission through the first electronically controlled clutch device, the second end of the first motor shaft and the first end of the second motor shaft are detachably connected by transmission through the second electronically controlled clutch device, and the second end of the second motor shaft and the power input shaft are detachably connected by transmission through the third electronically controlled clutch device.

[0008] Among them, the wheel assembly preferably further includes a motor housing and a brake, the hub motor and the steering motor are both accommodated in the motor housing, and the brake is installed between the motor housing and the wheel hub.

[0009] Among them, it is preferred that the outer diameters of the hub motor and the steering motor are comparable, and the motor housing is a cylindrical structure.

[0010] Wherein, preferably, the reducer includes a housing, and the housing is fixedly mounted on the motor housing.

[0011] Among them, the suspension system preferably 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 one above and one below in the vertical direction, one end of the upper swing arm is fixedly connected to the frame, and the other end is connected to the upper support arm through a ball head, and the upper support arm is also fixedly connected to the motor housing; one end of the lower swing arm is fixedly connected to the frame, and the other end is hinged to the lower support arm and the hinge axis is along the horizontal direction, the lower support arm and the reducer output shaft are connected by a shaft pin, and a thrust bearing is provided between the lower support arm and the reducer output shaft.

[0012] The present invention also provides a control method for a wheel assembly in which a hub motor and a steering motor are redundant with each other. Using the wheel assembly in which the hub motor and the steering motor are redundant with each other as described above, first, it is determined whether the hub motor and the steering motor are operating normally. If both the hub motor and the steering motor are operating normally, the normally closed first and third electronically controlled clutch devices remain in an engaged state, and the normally open second electronically controlled clutch device remains in a disengaged state. The hub motor drives the wheel to rotate, and the steering motor drives the wheel to steer. If the hub motor fails and the steering motor operates normally, the normally closed third electronically controlled clutch device is controlled to switch to a disengaged state, the normally open second electronically controlled clutch device is switched to an engaged state, the first electronically controlled clutch device continues to remain in an engaged state, and the steering motor temporarily drives the wheel to rotate. If the steering motor fails and the hub motor operates normally, the normally closed first electronically controlled clutch device is controlled to switch to a disengaged state, the normally open second electronically controlled clutch device is switched to an engaged state, the third electronically controlled clutch device continues to remain in an engaged state, and the hub motor temporarily drives the wheel to steer.

[0013] Among them, preferably, if the hub motor fails and the steering motor works normally, and the failure occurs in the rear wheel, it is determined whether the rear wheel is in a steering state. If the wheel is in a steering state, the steering motor is first controlled to drive the wheel to align, and then the normally closed third electronically controlled clutch device is controlled to switch to a disengaged state, the normally open second electronically controlled clutch device is switched to an engaged state, the first electronically controlled clutch device continues to remain in an engaged state, and the steering motor temporarily drives the wheel to rotate; if the wheel is not in a steering state, the normally closed third electronically controlled clutch device is directly controlled to switch to a disengaged state, the normally open second electronically controlled clutch device is switched to an engaged state, the first electronically controlled clutch device continues to remain in an engaged state, and the steering motor temporarily drives the wheel to rotate.

[0014] The present invention has the following beneficial effects: The in-wheel motor and steering motor are coaxially arranged side by side within the wheel hub cavity, effectively utilizing the internal space of the wheel hub cavity. This allows for a very compact arrangement of the in-wheel motor and steering motor, reducing the space occupied by the wheel assembly. By providing a first, second, and third electronically controlled clutch device, the in-wheel motor and steering motor maintain a compact layout while also providing redundant backup for each other, significantly improving vehicle driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of a wheel assembly in which the hub motor and the steering motor are redundant with each other in an embodiment;

[0016] Figure 2 Logic table showing that the hub motor and the steering motor are redundant with each other in the embodiment. DETAILED DESCRIPTION

[0017] To further illustrate various embodiments, the present invention is provided with accompanying drawings. These drawings form part of the present disclosure and are primarily used to illustrate the embodiments and, in conjunction with the relevant description in the specification, to explain the operating principles of the embodiments. By referring to these drawings, one of ordinary skill in the art will understand other possible embodiments and the advantages of the present invention. The components in the figures are not drawn to scale, and similar reference numerals are generally used to represent similar components.

[0018] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0019] See Figure 1 As shown, as a preferred embodiment of the present invention, a wheel assembly in which an in-wheel motor and a steering motor are redundant is provided, comprising a wheel 1, an in-wheel motor 2 for driving the wheel 1 to rotate, and a steering motor 3 for driving the wheel 1 to steer. The in-wheel motor 2 and the steering motor 3 are coaxially arranged side by side within the wheel hub cavity 15 of the wheel 1. The output shaft of the steering motor 3 is drivingly connected to a reducer 5. The reducer 5 is a right-angle reducer, i.e., the input and output shafts of the reducer 5 are arranged at a 90-degree angle. Thus, the reducer 5 not only increases and reduces the torque output by the steering motor 3, but also redirects the power output by the steering motor 3 90 degrees and transmits it to the suspension system, thereby achieving the steering function of the wheel 1. In this embodiment, the in-wheel motor 2 and the steering motor 3 are coaxially arranged side by side within the wheel hub cavity 15 of the wheel 1. This effectively utilizes the internal space of the wheel hub cavity 15, making the arrangement of the in-wheel motor 2 and the steering motor 3 very compact, reducing the space occupied by the wheel assembly, and facilitating the manufacture, assembly, and transportation of the wheel assembly. Furthermore, because the in-wheel motor 2 and the steering motor 3 are arranged side by side, their radial spacing does not interfere with each other. Therefore, the stators and rotors of the in-wheel motor 2 and the steering motor 3 can be designed with larger diameters, thereby increasing the output torque of the in-wheel motor 2 and the steering motor 3. In this embodiment, the outer diameters of the in-wheel motor 2 and the steering motor 3 are comparable, which not only ensures that the in-wheel motor 2 and the steering motor 3 have a larger output torque, but also makes their installation and coordination easier.

[0020] The wheel assembly of this embodiment also includes a first electronically controlled clutch device 16, a second electronically controlled clutch device 6 and a third electronically controlled clutch device 7. The hub of the wheel 1 includes a rotating shaft 101, the hub motor 2 includes a first motor shaft 201 for outputting its torque, the steering motor 3 includes a second motor shaft 301 for outputting its torque, and 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 coaxially arranged in sequence, and the rotating shaft 101 and the first end of the first motor shaft 201 are detachably connected in transmission through the first electronically controlled clutch device 16 (the detachable transmission connection means that the first electronically controlled clutch device 16 has two states of "disconnection" and "combination" to control the connection state of the first motor shaft 201 and the rotating shaft 101. The first electronically controlled clutch device 16 can be combined to enable the rotating shaft 101 and the first motor shaft 201 to be transmission-connected so as to transmit torque, and can also be separated to release the transmission connection between the rotating shaft 101 and the first motor shaft 201. The functions of the second electronically controlled clutch device 6 and the third electronically controlled clutch device 7 are similar and will not be repeated). The second end of the first motor shaft 201 and the first end of the second motor shaft 301 are detachably connected in transmission through the second electronically controlled clutch device 6, and the second end of the second motor shaft 301 and the power input shaft 501 are detachably connected in transmission through the third electronically controlled clutch device 7. Among them, when the vehicle is driving normally, the first electronically controlled clutch device 16 and the third electronically controlled clutch device 7 are normally closed (that is, they are kept in the engaged state under the usual conditions of normal vehicle driving), and the second electronically controlled clutch device 6 is normally open (that is, they are kept in the separated state under the usual conditions of normal vehicle driving). At this time, the steering motor 3 and the hub motor 2 do not interfere with each other, the hub motor 2 transmits power to the wheel 1, the steering motor 3 transmits power to the reducer 5 and then to the suspension system, and the hub motor 2 and the steering motor 3 each complete the rotation and steering of the wheel 1. However, if one of the steering motor 3 and the hub motor 2 suddenly fails, the other motor can provide emergency power support and temporarily take over the work of the failed motor, that is, the steering motor 3 and the hub motor 2 are redundant. Specifically:

[0021] 1. If the in-wheel motor 2 fails but the steering motor 3 operates normally, the electrical control system controls the third electronically controlled clutch device 7 to switch to the disengaged state and the second electronically controlled clutch device 6 to the engaged state. The first electronically controlled clutch device 16 does not switch and remains engaged. 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 wheel hub motor 1 operates normally, the electrical control system can control the first electronically controlled clutch device 16 to switch to the disengaged state and the second electronically controlled clutch device 6 to switch to the engaged state. The third electronically controlled clutch device 7 does not switch and remains in the engaged state. At this time, the power of the first motor shaft 201 is reversely transmitted to the power input shaft 501, and the wheel hub motor 2 drives the wheel 1 to steer.

[0023] In 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 straightens the rear wheel, then switches the state of the electronically controlled clutch device to reversely transmit the power of the second motor shaft 301 to the rotating shaft 101 to drive the wheel 1 to rotate. At this time, the rear wheel is straightened and the rear wheel still has forward power with the support of the steering motor 3. The steering function of the front wheel is normal, and the vehicle can still be turned. With this preferred design, the vehicle can continue to drive straight or turn after turning, giving the driver more time to react.

[0024] In this embodiment, whether the hub motor 2 and the steering motor 3 are faulty can be determined by providing a rotation speed sensor, and whether the wheel is in a steering state can be determined by providing an angle sensor.

[0025] Figure 2 A logic table diagram showing the mutual redundancy of the steering motor 3 and the hub motor 2 is shown, which can be referred to in conjunction.

[0026] Through the above arrangement, this embodiment enables the hub motor 2 and the steering motor 3 to serve as each other's safety redundant backup while having a very compact layout structure. That is, under normal circumstances, the hub motor 2 is used for driving and the steering motor 3 is used for steering. However, under specific working conditions where a motor fails, the hub motor 2 and the steering motor 3 can assist each other by regulating the first electronically controlled clutch device 16, the second electronically controlled clutch device 6 and the third electronically controlled clutch device 7. When one of the motors fails, the vehicle's operating state is temporarily maintained, giving the driver sufficient time to judge and check the vehicle condition, thereby greatly improving the safety of vehicle driving.

[0027] In this embodiment, the first electronically controlled clutch device 16 , the second electronically controlled clutch device 6 and the third electronically controlled clutch device 7 are specifically implemented by using automobile clutches.

[0028] In this embodiment, the wheel assembly also includes a motor housing 13 and a brake 4. The in-wheel motor 2 and the steering motor 3 are both housed within the motor housing 13, and the brake 4 is mounted between the motor housing 13 and the wheel hub of the wheel 1. That is, there is a mounting space between the motor housing 13 and the wheel 1 for mounting the brake 4. In this embodiment, the outer diameters of the in-wheel motor 2 and the steering motor 3 are comparable, so the motor housing 13 is a cylindrical structure, which makes the manufacture and assembly of the motor housing 13 more convenient. The mounting space between the motor housing 13 and the wheel hub of the wheel 1 includes both the axial gap between the motor housing 13 and the wheel hub, which can be used to install brake discs, brake calipers, etc., and the radial gap between the motor housing 13 and the wheel hub, which can be used to allow the brake line to pass through.

[0029] Reducer 5 is a right-angle bevel gear reducer, which uses a pair of meshing bevel gears to achieve a 90° change in power direction. It offers low cost and a reliable structure. Reducer 5 includes a housing 14, which is fixedly mounted to the motor housing 13 to facilitate the manufacture and installation of the entire wheel assembly.

[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 support arm 9 are arranged vertically, one above the other. One end of the upper swing arm 8 is fixedly connected to the vehicle frame, and the other end is connected to the upper support arm 9 via a ball joint. The upper support arm 9 is also fixedly connected to the motor housing. One end of the lower swing arm 11 is fixedly connected to the vehicle frame, and the other end is hinged to the lower support arm 10, with the hinge axis extending horizontally. The lower support arm 10 is connected to the output shaft of the reducer 5 via a pin, and a thrust bearing 12 is provided between the lower support arm 10 and the output shaft of the reducer 5. When the steering motor 3 generates a steering torque, it is decelerated, torque-increased, and direction-changed by the reducer 5. The torque is then transmitted to the lower support arm 10 via the pin connection between the output shaft of the reducer 5 and the lower support arm 10. However, since the lower support arm 10 cannot rotate about its vertical axis, the reaction torque to the steering torque rotates the wheel according to Newton's third law, achieving steer-by-wire. The horizontal articulation of the lower control arm 11 and the lower support arm 10 allows the wheel to bounce vertically, allowing for a certain amount of margin when the wheel bounces over uneven surfaces. The thrust bearing 12 has excellent axial load-bearing capacity, preventing excessive loads from acting on the lower control arm 11 and lower support arm 10 when the wheel bounces, thereby improving structural strength.

[0031] Based on the above-mentioned wheel assembly in which the hub motor and the steering motor are redundant with each other, this embodiment also proposes a control method for the wheel assembly in which the hub motor and the steering motor are redundant with each other. First, it is determined whether the hub motor 2 and the steering motor 3 are working normally. If the hub motor 2 and the steering motor 3 are working normally, the normally closed first electronically controlled clutch device 16 and the third electronically controlled clutch device 7 remain in the engaged state, and the normally open second electronically controlled clutch device 6 remains in the disengaged state. The hub motor 2 drives the wheel 1 to rotate, and the steering motor 3 drives the wheel 1 to steer. If the hub motor 2 fails, and the steering motor 3 fails, the hub motor 2 drives the wheel 1 to rotate, and the steering motor 3 drives the wheel 1 to steer. If the steering motor 3 is working normally, the normally closed third electronically controlled clutch device 7 is controlled to switch to the disengaged state, the normally open second electronically controlled clutch device 6 is switched to the engaged state, the first electronically controlled clutch device 16 continues to remain in the engaged state, and the steering motor 3 temporarily drives the wheel 1 to rotate; if the steering motor 3 fails and the wheel hub motor 2 is working normally, the normally closed first electronically controlled clutch device 16 is controlled to switch to the disengaged state, the normally open second electronically controlled clutch device 6 is switched to the engaged state, the third electronically controlled clutch device 7 continues to remain in the engaged state, and the wheel hub motor 2 temporarily drives the wheel 1 to steer.

[0032] If the hub motor 2 fails while the steering motor 3 operates normally, and the rear wheel fails, the system determines whether the rear wheel 1 is in the steering state. If the wheel 1 is in the steering state, the steering motor 3 is first controlled to drive the wheel 1 to align. The normally closed third electronically controlled clutch 7 is then controlled to switch to the disengaged state, the normally open second electronically controlled clutch 6 is switched to the engaged state, and the first electronically controlled clutch 16 remains in the engaged state, with the steering motor 3 driving the wheel 1 to rotate. If the wheel 1 is not in the steering state, the normally closed third electronically controlled clutch 7 is directly controlled to switch to the disengaged state, the normally open second electronically controlled clutch 6 is switched to the engaged state, and the first electronically controlled clutch 16 remains in the engaged state, with the steering motor 3 driving the wheel 1 to rotate.

[0033] Through the above control method, the hub motor 2 and the steering motor 3 can serve as each other's safety redundant backup, that is, under normal circumstances, the hub motor 2 is used for driving and the steering motor 3 is used for steering. However, under specific working conditions where a motor fails, the mutual assistance function of the hub motor 2 and the steering motor 3 can be achieved by regulating the first clutch device 6 and the second clutch device 7. When one of the motors fails, the vehicle's operating state is temporarily maintained, giving the driver sufficient time to judge and check the vehicle condition, thereby greatly improving the safety of vehicle driving.

[0034] Although the present invention has been particularly shown and described in conjunction with preferred embodiments, it should be understood by those skilled in the art that various changes in form and details made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims fall within the scope of protection of the present invention.

Claims

1. A wheel assembly in which the in-wheel motor and steering motor are redundant, comprising a wheel, an in-wheel motor, a steering motor, a speed reducer, and a suspension system. The in-wheel motor is drivingly connected to the wheel hub to drive the wheel, and the steering motor is drivingly connected to the suspension system via the speed reducer to drive the wheel steering. The assembly is characterized by: The hub motor and the steering motor are coaxially arranged side by side in the hub cavity of the wheel. The reducer is a right-angle reducer that changes the power output by the steering motor by 90 degrees and then transmits it to the suspension system. It also includes a first electronically controlled clutch device, a second electronically controlled clutch device and a third electronically controlled clutch device. The hub of the wheel includes a rotating shaft, the hub motor includes a first motor shaft that outputs its torque, the steering motor includes a second motor shaft that outputs its torque, and the reducer includes a power input shaft. The rotating shaft, the first motor shaft, the second motor shaft and the power input shaft are coaxially arranged in sequence. The rotating shaft and the first end of the first motor shaft are detachably connected by transmission through the first electronically controlled clutch device, the second end of the first motor shaft and the first end of the second motor shaft are detachably connected by transmission through the second electronically controlled clutch device, and the second end of the second motor shaft and the power input shaft are detachably connected by transmission through the third electronically controlled clutch device.

2. The wheel assembly with a hub motor and a steering motor being redundant with each other according to claim 1, characterized in that: It also includes a motor housing and a brake. The hub motor and the steering motor are both accommodated in the motor housing. The brake is installed between the motor housing and the wheel hub. The installation space between the motor housing and the wheel hub includes both the gap between the motor housing and the wheel hub in the axial direction and the gap between the motor housing and the wheel hub in the radial direction.

3. The wheel assembly with a hub motor and a steering motor being redundant with each other according to claim 2, characterized in that: The outer diameters of the hub motor and the steering motor are comparable, and the motor housing is a cylindrical structure.

4. The wheel assembly with a hub motor and a steering motor being redundant with each other according to claim 2, characterized in that: The reducer includes a housing, and the housing is fixedly mounted on the motor housing.

5. The wheel assembly with a hub motor and a steering motor being redundant with each other according to claim 4, characterized in that: 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 one above the other in the vertical direction. One end of the upper swing arm is fixedly connected to the vehicle frame, and the other end is connected to the upper support arm through a ball head. The upper support arm is also fixedly connected to the motor housing; one end of the lower swing arm is fixedly connected to the vehicle frame, and the other end is hinged to the lower support arm and the hinge axis is along the horizontal direction. The lower support arm and the output shaft of the reducer are connected by a shaft pin, and a thrust bearing is provided between the lower support arm and the output shaft of the reducer.

6. A control method for a wheel assembly in which the hub motor and the steering motor are redundant, characterized in that: Using a wheel assembly in which the hub motor and the steering motor are redundant with each other as described in any one of claims 1 to 5, first determine whether the hub motor and the steering motor are operating normally; if both the hub motor and the steering motor are operating normally, the normally closed first and third electronically controlled clutch devices remain in an engaged state, the normally open second electronically controlled clutch device remains in a disengaged state, the hub motor drives the wheel to rotate, and the steering motor drives the wheel to steer; if the hub motor fails and the steering motor operates normally, the normally closed third electronically controlled clutch device is controlled to switch to a disengaged state, the normally open second electronically controlled clutch device is switched to an engaged state, the first electronically controlled clutch device continues to remain in an engaged state, and the steering motor temporarily drives the wheel to rotate; If the steering motor fails and the wheel hub motor works normally, the normally closed first electronically controlled clutch device is controlled to switch to the disengaged state, the normally open second electronically controlled clutch device is switched to the engaged state, and the third electronically controlled clutch device continues to remain in the engaged state, and the wheel hub motor temporarily drives the steering.

7. The control method of a wheel assembly in which the hub motor and the steering motor are redundant with each other according to claim 6, characterized in that: If the hub motor fails, but the steering motor works normally, and the failure occurs in the rear wheel, it is determined whether the rear wheel is in the steering state. If the wheel is in the steering state, the steering motor is controlled to drive the wheel to straighten first, and then the normally closed third electronically controlled clutch device is controlled to switch to the disengaged state, the normally open second electronically controlled clutch device is switched to the engaged state, the first electronically controlled clutch device continues to remain in the engaged state, and the steering motor temporarily drives the wheel to rotate; if the wheel is not in the steering state, the normally closed third electronically controlled clutch device is directly controlled to switch to the disengaged state, the normally open second electronically controlled clutch device is switched to the engaged state, the first electronically controlled clutch device continues to remain in the engaged state, and the steering motor temporarily drives the wheel to rotate.

Images