Patent Application
20240367502
The present disclosure relates to a hub motor driving system for a new energy automobile. A driving motor, a wheel bearing, and a drum brake are integrated into a wheel space, such that the wheel space is effectively utilized, and a wheel is directly driven by the driving motor without the need for clutches and transmission shafts. In addition, the present disclosure further relates to a vehicle provided with a hub motor driving system.
Hub motor technology is also called in-wheel motor technology, with the biggest feature thereof being that power, transmission, and braking devices are integrated into a hub, thus greatly simplifying mechanical parts of electric vehicles. A driving motor may be directly mounted in a hub of a wheel. When driving the wheel, the driving motor directly outputs driving torque to the wheel, and when the wheel is braked, this is achieved by means of a brake mounted outside a hub driver.
CN201710507523, CN201710077995, and CN201910256999 disclose a hub driving device provided with a differential planetary gear reducer. A driving motor is supported on a wheel axle fixedly connected to a frame of a vehicle by means of a motor bearing. In addition, a wheel bearing is provided on the wheel axle, and is used for bearing a load that a wheel should bear.
CN103328247A, CN103026103A, and CN102648362A disclose a hub driving device provided with a cycloidal gear reducer. This hub driving device has a structure similar to that of the above-mentioned hub driving device provided with a differential planetary gear reducer and is also provided with a wheel bearing and a motor bearing to bear loads of a motor and a wheel, respectively.
In order to achieve higher driving torque performance using current direct driving devices, the diameter of a motor is very large. Therefore, the motor is only suitable for large-size tires, and requirements on motor bearings are also very high. In existing wheel driving devices provided with gear reducers, wheel bearings, reducers, brakes, and driving motors are simply integrated together. An overall mounting width is large, and thus the scope of application is limited. There is an urgent need in the market to reduce axial sizes of hub driving systems.
According to one aspect of the present disclosure, a hub motor driving system for a vehicle is relatively small in the axial dimension and is relatively cost effective with regard to component costs. The hub motor driving system comprises: a wheel axle fixedly connected to a frame of the vehicle; a driving motor provided with a motor stator and a motor rotor which is located on a radial inner side of the motor stator and can rotate relative to the motor stator, the driving motor and the wheel axle being coaxially disposed; an output flange which radially supports the motor rotor and rotates along with the motor rotor, wherein the output flange is connected to a wheel rim of a wheel on the axial direction side in an anti-torque manner; and bearing devices radially supported between the output flange and the wheel axle, wherein the bearing devices bear both a load of the driving motor and a load of the wheel axle.
As described in the background art above, existing hub motor driving systems generally comprise two independent bearing devices, which are used as a motor bearing for bearing a load of a driving motor and a wheel bearing for bearing a load of a wheel, respectively. According to an aspect of the present disclosure, a bearing device of the hub motor driving system disclosed herein is used not only as a wheel bearing but also as a motor bearing, thus reducing the number of bearings, and the axial size of the hub motor driving system can be reduced. In addition, the present disclosure provides for coaxial disposition of the driving motor and the bearing devices, such that a space occupied by a driving device is greatly reduced. The driving device is integrated onto the wheel, which facilitates the layout of the vehicle, and reduces the impact of space interference during bumping and turning. By integrating the motor rotor onto the wheel rim, power can be directly transmitted from the motor rotor to the wheel, such that power transmission efficiency is improved.
According to some embodiments of the present disclosure, the hub motor driving system comprises braking devices, wherein the braking devices and the wheel axle are coaxially disposed. Since the driving motor, bearing devices, and braking devices are all coaxially disposed, space is saved, and the stability of the system is improved. The output flange may be connected to the braking devices on the other axial direction side in an anti-torque manner. According to the present disclosure, the output flange is connected to the wheel rim on the axial direction side in an anti-torque manner and is connected to the braking devices on the other axial direction side in an anti-torque manner, thereby simplifying a drivetrain of the hub motor driving system and improving torque transmission efficiency.
According to some embodiments of the present disclosure, the driving motor is provided with a motor housing and a motor housing cover, and the motor stator of the driving motor is supported by the motor housing cover, wherein the motor housing and the motor housing cover are supported on the output flange. A protective shell for the driving motor is formed by the motor housing and the motor housing cover to prevent external factors from affecting the operation of the motor. The motor housing and the motor housing cover are also supported on the output flange, such that the structure of the system is simplified. A motor vibration bearing may be provided between the output flange and the motor housing cover. Since the hub motor driving system is mounted on the wheel, bumping may occur during actual operation. In order to prevent the performance of the driving motor from being affected, the motor vibration bearing is provided to provide support for the motor stator when vibration occurs, so as to maintain the stability of the motor stator. A first sealing member may be provided between the motor housing and the output flange, and a second sealing member is provided between the motor housing cover and the output flange. The first and second sealing members are used for keeping a motor compartment clean and preventing dust and muddy water from entering the motor compartment.
According to some embodiments of the present disclosure, the bearing devices comprise an outer bearing provided on the axial direction side and an inner bearing provided on the other axial direction side, wherein the outer bearing and the inner bearing are spaced apart from each other in an axial direction. A pair of bearings is used to form a bearing group, and the two bearings cooperate with each other to constitute a more stable supporting structure. In order to simplify the structure, the output flange supports the motor rotor by means of a motor rotor support, wherein the motor rotor support is connected to the output flange and the motor rotor in a radial direction in an anti-torque manner, and the motor rotor transmits torque to the output flange by means of the motor rotor support, thereby shortening the power transmission path, and improving the power transmission efficiency. It may also be considered that a wheel rim positioning member is provided on the output flange, and the output flange is connected to the wheel rim by means of the wheel rim positioning member, such that the output flange and the wheel rim are accurately connected in an extremely convenient manner to transmit the torque to the wheel rim by means of the output flange, thereby reducing component costs, and simplifying the structure.
In addition, a vehicle may be provided with the hub motor driving system according to the description above.
Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. Drawings are as follows:
Specific embodiments of the hub driving system according to the present disclosure will be described below with reference to the drawings. The following detailed description and drawings are intended to exemplarily illustrate the principle of the present disclosure. The present disclosure is not limited to the described preferred embodiments, and the scope of protection of the present disclosure is defined by the claims.
In addition, space-related terms (such as “upper”, “lower”, “left”, and “right”) are used for describing the relative position relationship of one element to another element as shown in the drawings. Therefore, the space-related terms may be applied to directions that are different from those shown in the drawings when in use. Obviously, although all of the space-related terms refer to the directions shown in the drawings for ease of explanation, a person skilled in the art can understand that directions different from those shown in the drawings may be used. In this specification, the terms “axial (direction)”, “radial (direction)”, and “circumferential (direction)” refer to the axial direction, radial direction, and circumferential direction of a housing of a hub motor driving system, respectively, the axial direction side refers to the left side in
As shown in
The driving motor comprises a motor stator 3 and a motor rotor 4, wherein the motor rotor 4 is connected to an output flange 6 in an anti-torque manner by means of a motor rotor support 5. The output flange 6 and the wheel axle 8 are also coaxially disposed. The output flange 6 is fixedly connected to a wheel rim 26 on the axial direction side and is fixedly connected to a brake drum 21 on the other axial direction side. The weight of the driving motor is transmitted to the output flange 6 by means of the rotor support, and the output flange 6 bears a load of the driving motor. A motor housing 1 is provided on an outer side of the driving motor, for protecting and supporting the driving motor, and the motor housing 1 can simultaneously serve as a part of a cooling device 2. The cooling device 2 is assembled on the motor housing 1, and a cooling passage is formed to cool the motor stator 3. The cooling device 2 is further provided with a cooling joint 12 provided on the motor housing 1. The driving motor is closed, on the other axial direction side, by means of a motor housing cover 13. In addition, a stator sensor 16 for monitoring the motor stator 3 is assembled on the motor housing cover 13, and a rotor sensor 15 for monitoring the motor rotor 4 is assembled on the motor rotor support 5. On a side facing the wheel rim 26, a sealing member 11 is provided between the motor housing 1 and the output flange 6, for keeping a motor compartment clean and preventing dust and muddy water from entering the motor compartment. On the other axial direction side, a sealing member 20 is provided between the motor housing cover 13 and the output flange 6, which is also used for keeping the motor compartment clean and preventing dust and muddy water from entering the motor compartment.
The bearing devices comprise an outer bearing 7 located on the axial direction side and an inner bearing 18 located on the other axial direction side, wherein the outer bearing 7 and the inner bearing 18 are placed between the output flange 6 and the wheel axle 8, and are sleeved on the wheel axle 8; therefore, the outer bearing 7 and the inner bearing 18 are used as wheel bearings to support the weight of the vehicle 22, and are also used as motor bearings to bear the load of the driving motor, i.e., serving as both a wheel bearing and a motor bearing at the same time. In this embodiment, only a pair of bearings is provided for supporting the weight of the vehicle 22 and the motor at the same time, such that the number of bearings is saved, space requirements are reduced, in particular, the axial space of the hub motor driving system 25 is reduced, and costs are reduced. In addition, as shown in
The braking devices comprise a brake pad 19 and the brake drum 21. The brake pad 19 is connected to the motor housing cover 13 by means of an outer cover plate 14, and the brake drum 21 is connected to the output flange 6 in an anti-torque manner.
Driving torque of the hub motor driving system 25 according to the present disclosure is transmitted in the system in a manner that: the motor rotor 4 of the driving motor generates driving torque and transmits the driving torque to the motor rotor support 5; since the motor rotor support 5 is connected to the output flange 6 in an anti-torque manner, the driving torque is further transmitted to the output flange 6; and the output flange 6 is connected to the wheel rim 26 in an anti-torque manner, thereby transmitting the driving torque to the wheel 24 by means of the wheel rim 26 to drive the wheel 24 to rotate.
The braking devices of the hub motor driving system 25 according to the present disclosure work in a manner that: when braking is required, the system controls the brake pad 19 to transmit braking torque to the brake drum 21; and since the brake drum 21 is fixedly connected to the output flange 6, the brake drum 21 transmits the braking torque to the wheel rim 26 by means of the output flange 6, thereby causing the wheel 24 to be braked.
Although possible embodiments have been described illustratively in the above description, it should be understood that there are still a large number of embodiment variations through combinations of all known technical features and embodiments as well as those that are readily apparent to those skilled in the art. In addition, it should be further understood that the exemplary embodiments are just examples and shall not in any way limit the scope of protection, application and construction of the present disclosure. The foregoing description is more intended to provide a person skilled in the art with a technical guide for converting at least one exemplary embodiment, in which various changes can be made as long as they do not depart from the scope of protection of the claims.
This application is a U.S. national stage application under 35 U.S.C. § 371 that claims the benefit of priority under 35 U.S.C. § 365 of International Patent Application No. PCT/CN2021/116887, filed on Sep. 7, 2021, designating the United States of America, the contents of which are relied upon and incorporated herein by reference in their entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2021/116887 | 9/7/2021 | WO |
