Self-pre-tightening bearing for small high-speed hub motor
The self-preloaded bearing with a wave spring washer addresses the preload challenge in small high-speed hub motors, eliminating resonance and noise, and extending motor life by over 30% through axial preload without altering the motor's design.
Patent Information
- Application Number
- CN202323632132.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-29
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2033-12-29
AI Technical Summary
Small-sized high-speed hub motors face challenges in achieving effective axial preload due to their compact design, leading to resonance and noise issues, which affect performance and lifespan.
A self-preloaded bearing with a wave spring washer installed on the inner ring, applying an axial preload force through the motor shaft's shoulder end face, eliminating resonance and extending motor life by over 30%.
The solution effectively eliminates high-speed resonance and noise, enhancing motor performance and extending its service life by more than 30% without altering the motor's internal space or accessories.
Smart Images
Figure CN222185516U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a self-preload bearing, in particular to a self-preload bearing for a small-sized high-speed wheel hub motor. Background Art
[0002] Generally, large-sized high-speed motors use the base shaft system, that is, the outer ring of the bearing is fixed, the inner ring of the bearing rotates, the motor shaft and the inner ring of the bearing have an interference fit, the bearing chamber and the outer ring of the bearing have a clearance fit, and the internal space of the bearing chamber is large. Usually, axial preload can be performed by adding gaskets to the motor shaft. However, small-sized high-speed hub motors with smaller sizes often use the base hole system, that is, the outer ring of the bearing rotates, the inner ring of the bearing is fixed, the bearing chamber and the outer ring of the bearing have an interference fit, and the motor shaft and the inner ring of the bearing have a clearance fit. Therefore, the bearing processing is more difficult, the axial spacing is not easy to control, and the internal space of the bearing chamber is small, so it is difficult to perform axial preload by adding gaskets. Due to the lack of an effective axial preload structure, the hub bearing of a small-sized high-speed hub motor with a base hole system is prone to resonance and abnormal sounds and noise at high speeds, which seriously affects the use and life of the motor. Utility Model Content
[0003] The technical problem to be solved by the utility model is to provide a self-preloaded bearing for a small high-speed hub motor in view of the deficiencies in the prior art, which can completely eliminate the bearing resonance phenomenon generated when the hub motor rotates at high speed, avoid resonance noise, and extend the service life of the hub motor by more than 30%.
[0004] The technical solution adopted by the utility model to solve the above technical problems is: a self-preloaded bearing for a small high-speed hub motor, comprising a bearing outer ring, a bearing inner ring and a steel ball, a retainer and a sealing ring are installed between the bearing outer ring and the bearing inner ring, the steel ball is installed on the retainer, the bearing inner ring is used for clearance fitting installation of the motor shaft, a wave spring washer is coaxially installed at one end of the bearing inner ring, one end of the wave spring washer is connected to the bearing inner ring, the other end of the wave spring washer exceeds one end face of the bearing inner ring, the inner diameter of the wave spring washer is larger than the inner diameter of the bearing inner ring, and the inner diameter of the wave spring washer is smaller than the outer diameter of the shoulder end face of the motor shaft.
[0005] When the self-preloaded bearing of the utility model is installed, one end of the wave spring washer is connected to the inner ring of the bearing, and the other end of the wave spring washer contacts the shoulder end face of the motor shaft. After the motor cover is tightened, the shoulder end face of the motor shaft applies axial pressure to the wave spring washer, thereby forming an axial preload force on the inner ring of the bearing. The axial preload force is controlled to be about 1% to 1.5% of the rated dynamic load of the bearing, so that the bearing resonance phenomenon generated when the hub motor rotates at high speed can be completely eliminated, the resonance noise can be avoided, and the service life of the hub motor can be extended by more than 30%.
[0006] The utility model directly installs the wave spring washer on the inner ring of the bearing, which does not affect the installation of the motor shaft, does not need to change or adjust any hub motor accessories, does not increase the internal space of the hub motor, can be directly installed and used in the hub motor, and improves the assembly accuracy of the hub motor.
[0007] Preferably, a slot is provided at the connection between one end face of the bearing inner ring and the inner surface of the bearing inner ring, and a buckle is provided at one end of the wave spring washer, and the buckle is embedded in the slot. The connection between the wave spring washer and the bearing inner ring is achieved through the cooperation of the buckle and the slot, and the assembly is convenient.
[0008] Preferably, an annular step surface is provided at the connection between the end face of one end of the bearing inner ring and the inner surface of the bearing inner ring, the clamping groove is an annular U-shaped groove, the U-shaped groove is provided on the axially outer side and the radially outer side of the step surface, the number of the buckles is multiple, the multiple buckles are arranged at equal intervals along the outer circumference of the wave spring washer, the multiple buckles are embedded in the U-shaped groove, and one end of the wave spring washer contacts the step surface. The design of the step surface and the U-shaped groove is conducive to increasing the contact area between one end of the wave spring washer and the bearing inner ring, and has a good positioning effect, which can improve the reliability of the installation of the wave spring washer.
[0009] Preferably, each of the buckles is arranged obliquely and is inclined toward the radial outer side of the wave spring washer. The buckles are arranged obliquely, so that when the shoulder end surface of the motor shaft applies axial pressure to the wave spring washer, the buckles can firmly press the inner ring of the bearing from the radial direction, thereby achieving a better positioning effect on one end of the wave spring washer.
[0010] Preferably, the angle between each buckle and the center line of the wave spring washer is 13° to 18°.
[0011] Preferably, the distance that the other end of the wave spring washer exceeds the end surface of one end of the bearing inner ring is 1.5 mm to 2.0 mm.
[0012] Compared with the prior art, the utility model has the following advantages: the utility model directly installs the wave spring washer on the inner ring of the bearing, which does not affect the installation of the motor shaft, does not need to change and adjust any wheel hub motor accessories, does not increase the internal space of the wheel hub motor, can be directly installed and used in the wheel hub motor, and improves the assembly accuracy of the wheel hub motor. After the self-preloaded bearing of the utility model is installed, an axial preload force is formed on the inner ring of the bearing, which can completely eliminate the bearing resonance phenomenon generated when the wheel hub motor rotates at high speed, avoid resonance noise, and extend the service life of the wheel hub motor by more than 30%. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 is a structural cross-sectional view of a self-preloaded bearing in an embodiment;
[0014] Figure 2 for Figure 1 Enlarged view of point A in the middle;
[0015] Figure 3 is an appearance diagram of a wave spring washer in an embodiment;
[0016] Figure 4 This is a schematic diagram of the effect of the self-preloaded bearing after installation in the embodiment;
[0017] The specific reference numerals in the figure are as follows:
[0018] 1-bearing outer ring, 2-bearing inner ring, 21-slot, 22-step surface, 3-steel ball, 4-retainer, 5-sealing ring, 6-wave spring washer, 61-buckle, 7-motor shaft, 71-shoulder end face, 8-bearing chamber. DETAILED DESCRIPTION
[0019] The present invention will be described in further detail below in conjunction with the accompanying drawings.
[0020] The self-preloaded bearing for a small high-speed hub motor of an embodiment, such as Figure 1 to Figure 3 As shown, it includes a bearing outer ring 1, a bearing inner ring 2 and a steel ball 3, a retainer 4 and a sealing ring 5 are installed between the bearing outer ring 1 and the bearing inner ring 2, the steel ball 3 is installed on the retainer 4, the bearing inner ring 2 is used for installing the motor shaft 7 with clearance fit, and a wave spring washer 6 is coaxially installed at one end of the bearing inner ring 2, one end of the wave spring washer 6 is connected to the bearing inner ring 2, and the other end of the wave spring washer 6 exceeds the end face of one end of the bearing inner ring 2 by a distance h of 1.5 mm, the inner diameter of the wave spring washer 6 is larger than the inner diameter of the bearing inner ring 2, and the inner diameter of the wave spring washer 6 is smaller than the outer diameter of the shoulder end face 71 of the motor shaft 7.
[0021] In this embodiment, a slot 21 is provided at the connection between the end face of one end of the bearing inner ring 2 and the inner surface of the bearing inner ring 2, and a buckle 61 is provided at one end of the wave spring washer 6, and the buckle 61 is embedded in the slot 21. In a specific implementation scheme, an annular step surface 22 is provided at the connection between the end face of one end of the bearing inner ring 2 and the inner surface of the bearing inner ring 2. The slot 21 is an annular U-shaped groove, and the U-shaped groove is provided on the axial outside and radial outside of the step surface 22. There are four buckles 61, and the four buckles 61 are arranged at equal intervals along the outer circumference of the wave spring washer 6. The four buckles 61 are embedded in the U-shaped groove, and one end of the wave spring washer 6 is in contact with the step surface 22.
[0022] In this embodiment, each buckle 61 is tilted and inclined toward the radial outer side of the wave spring washer 6 , and the angle θ between each buckle 61 and the center line of the wave spring washer 6 is 15°.
[0023] See the schematic diagram of the effect of the above self-preloaded bearing after installation. Figure 4 .
[0024] When the above-mentioned self-preloaded bearing is installed, one end of the wave spring washer 6 is connected to the bearing inner ring 2, and the other end of the wave spring washer 6 contacts the shoulder end face 71 of the motor shaft 7. After the motor cover is tightened, the shoulder end face 71 of the motor shaft 7 applies axial pressure to the wave spring washer 6, thereby forming an axial preload force on the bearing inner ring 2. The axial preload force is controlled to about 1% to 1.5% of the rated dynamic load of the bearing, which can completely eliminate the bearing resonance phenomenon generated when the hub motor rotates at high speed, avoid resonance noise, and extend the service life of the hub motor by more than 30%.
Claims
1. A self-preloaded bearing for a small high-speed hub motor, comprising a bearing outer ring, a bearing inner ring and a steel ball, a retainer and a sealing ring are installed between the bearing outer ring and the bearing inner ring, the steel ball is installed on the retainer, and the bearing inner ring is used for clearance fitting to install the motor shaft, characterized in that: A wave spring washer is coaxially installed at one end of the bearing inner ring, one end of the wave spring washer is connected to the bearing inner ring, the other end of the wave spring washer extends beyond one end face of the bearing inner ring, the inner diameter of the wave spring washer is larger than the inner diameter of the bearing inner ring, and the inner diameter of the wave spring washer is smaller than the outer diameter of the shoulder end face of the motor shaft.
2. The self-preloaded bearing for a small high-speed hub motor according to claim 1, characterized in that: A slot is provided at the connection between one end surface of the bearing inner ring and the inner surface of the bearing inner ring, and a buckle is provided at one end of the wave spring washer, and the buckle is embedded in the slot.
3. The self-preloaded bearing for a small high-speed hub motor according to claim 2, characterized in that: An annular step surface is provided at the connection between one end face of the bearing inner ring and the inner surface of the bearing inner ring, the groove is an annular U-shaped groove, the U-shaped groove is provided on the axially outer side and the radially outer side of the step surface, the number of the buckles is multiple, and the multiple buckles are arranged at equal intervals along the outer circumference of the wave spring washer, the multiple buckles are embedded in the U-shaped groove, and one end of the wave spring washer is in contact with the step surface.
4. The self-preloaded bearing for a small high-speed hub motor according to claim 3, characterized in that: Each of the buckles is tilted and inclined toward the radial outside of the wave spring washer.
5. The self-preloaded bearing for a small high-speed hub motor according to claim 4, characterized in that: The angle between each buckle and the center line of the wave spring washer is 13° to 18°.
6. The self-preloaded bearing for a small high-speed hub motor according to claim 1, characterized in that: The distance that the other end of the wave spring washer exceeds the end surface of one end of the bearing inner ring is 1.5mm to 2.0mm.