Current corrosion prevention structure of electric drive assembly bearing
By using a combination of insulating cover and conductive fiber structure in the electric drive assembly, the corrosion problem of bearings in the electric drive assembly is solved, thus achieving low-cost, reliable bearing protection and convenient maintenance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WUXI CRRC HOFER POWERTRAIN CO LTD
- Filing Date
- 2025-05-28
- Publication Date
- 2026-05-08
AI Technical Summary
Existing electric drive assembly bearings are susceptible to shaft current corrosion under high voltage and high frequency conditions, leading to NVH problems and reduced reliability. Ceramic ball bearings are expensive and the replacement of conductive components is difficult. Existing conductive components are complex to install and difficult to maintain.
The structure combines an insulating cover and conductive components. The insulating cover blocks the closed loop of shaft current, while the conductive fibers facilitate current flow and conduct it through the grounding wire. Combined with a limiting platform and sealing ring, it ensures stable installation and convenient replacement.
It effectively protects bearings from electrolytic corrosion, extends service life, reduces costs, simplifies installation and replacement processes, and reduces maintenance difficulty and labor costs.
Smart Images
Figure CN224218184U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of electric drive technology, specifically relating to an anti-current corrosion structure for bearings of electric drive assemblies. Background Technology
[0002] Most new energy vehicles currently use electric drive assemblies as their drive units. However, with the increasing high voltage of electric drive platforms and the high frequency of controller switching, NVH and reliability issues caused by shaft current corrosion of motor bearings are receiving increasing attention from the industry. Existing technologies typically use ceramic ball bearings to block the shaft current flow path and / or bypass the current by arranging conductive components to avoid or reduce the impact of shaft current on the electric drive system bearings. However, ceramic ball bearings are expensive, which is detrimental to controlling the manufacturing cost of the electric drive assembly. Furthermore, the conductive components form rolling contact with the motor shaft; after prolonged use, increased wear leads to increased contact resistance with the motor shaft, affecting conductivity. Therefore, the conductive components need to be replaced periodically. However, most existing conductive components are built-in, which presents problems of cumbersome disassembly and replacement. Although some solutions employ detachable mounting structures, these also suffer from complex installation structures, hindering processing and assembly. Utility Model Content
[0003] The technical problem to be solved by this utility model is to provide an electric drive assembly bearing anti-current corrosion structure that better protects the bearings of the electric drive assembly, extends their service life, has a relatively lower cost, ensures that the conductive components are installed securely and reliably and are easy to replace, and reduces maintenance difficulty and labor costs.
[0004] This utility model includes an insulating cover and a conductive component. The insulating cover is disposed inside the bearing mounting area at one end of the electric drive assembly. The bearing inside the electric drive assembly at that end is disposed inside the insulating cover, and the end of the insulating cover has a through hole through which the electric drive shaft passes. The housing end face at the other end of the electric drive assembly is provided with a threaded hole. The conductive component includes a column and conductive fibers. One end of the column is provided with an external thread, and the conductive fibers are disposed at the other end of the column. The column is threadedly connected to the threaded hole. The end of the column with the conductive fibers is located inside the other end of the electric drive assembly, and the conductive fibers are in contact with the electric drive shaft.
[0005] Furthermore, the conductive fiber is disposed on the other side of the column, and the end of the electric drive shaft opposite to the insulating cover is hollow. The end of the column with the conductive fiber passes through the hollow end of the electric drive shaft, and the conductive fiber contacts the inner wall of the electric drive shaft.
[0006] Furthermore, the conductive fiber has several bundles, which are spaced apart circumferentially and / or axially on the side of the column.
[0007] Furthermore, a limiting platform is provided at one end of the column with external threads. The width or diameter of the limiting platform is greater than the diameter of the column. After the column is threadedly connected to the threaded hole, the limiting platform is located outside the electric drive assembly housing.
[0008] Furthermore, the limiting platform has an internal hexagonal hole in the middle, or the limiting platform is hexagonal.
[0009] Furthermore, it also includes a sealing ring, wherein the side of the limiting platform facing the electric drive assembly housing is provided with an annular groove, and the sealing ring is disposed in the annular groove and abuts against the electric drive assembly housing.
[0010] Furthermore, it also includes a wave spring located inside the insulating cover, which is sleeved on the motor shaft and contacts the outer ring end face of the bearing located inside the insulating cover.
[0011] Furthermore, the insulating cover includes an insulating ring and an insulating plate, the insulating plate being disposed at one end of the insulating ring, and the through hole being formed in the middle of the insulating plate.
[0012] Furthermore, a fixing plate is provided on the side of the insulating ring away from the insulating plate, and a fixing hole is provided on the fixing plate.
[0013] Furthermore, two fixing plates are symmetrically arranged along the axis of the insulating ring.
[0014] The beneficial effects of this invention are that the insulating cover inside the electric drive assembly effectively blocks the shaft current from forming a closed loop, thereby blocking the electro-corrosion effect of high-frequency circulating current on the bearing. The conductive component can facilitate the conduction of accumulated current at the other end of the electric drive assembly. The current is ultimately conducted away after passing through conductive fibers, forming a method of blocking at one end and conducting at the other, which better protects the bearing of the electric drive assembly and extends its service life. Compared to using ceramic ball bearings, the cost is relatively lower, which helps control the overall production cost of the electric drive assembly. Furthermore, the conductive component used to conduct current is installed securely and reliably, and is easy and quick to install and remove, facilitating the replacement of the conductive component and reducing maintenance difficulty and labor costs. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the anti-current corrosion structure of the bearing of the electric drive assembly of this utility model.
[0016] Figure 2 This is a schematic diagram of the insulating cover in this utility model.
[0017] Figure 3 This is a schematic diagram of the conductive component in this utility model.
[0018] In the diagram: 1. Insulating cover; 11. Insulating ring; 12. Insulating plate; 121. Through hole; 13. Fixing plate; 131. Fixing hole; 2. Conductive component; 21. Column; 211. External thread; 22. Conductive fiber; 23. Limiting platform; 231. Internal hexagonal hole; 100. Electric drive assembly; 101. Threaded hole; 102. Motor shaft; 103. Input shaft. Detailed Implementation
[0019] For example, 1- Figure 3 As shown in the figure, this utility model provides an anti-current corrosion structure for an electric drive assembly bearing, including an insulating cover 1 and a conductive component 2. The insulating cover 1 is disposed inside the bearing mounting area at one end of the electric drive assembly 100. The bearing inside this end of the electric drive assembly 100 is mounted inside the insulating cover 1, and the end of the insulating cover 1 has a through hole 121 through which the electric drive shaft passes. In specific applications, the inner diameter of the bearing mounting area is enlarged, and after the insulating cover 1 is installed, the bearing corresponding to this position is further installed through the insulating cover 1. The housing end face at the other end of the electric drive assembly 100 is provided with a threaded hole 101. The conductive component 2 includes a column 21 and a conductive fiber 22. One side of the column 21 is provided with an external thread 211, and the conductive fiber 22 is disposed at the other end of the column 21. The column 21 passes through the threaded hole 101 and is threadedly connected to the threaded hole 101, so that the end of the column 21 with the conductive fiber 22 is located inside the other end of the electric drive assembly 100, and the conductive fiber 22 is in contact with the electric drive shaft. In one embodiment of this invention, a grounding wire connects the post 21 or the conductive fiber 22, and the current flows through the conductive fiber 22 and is conducted to the ground via the grounding wire. In another embodiment of this invention, a grounding point is provided on the surface of the housing of the electric drive assembly 100 and a grounding wire is connected thereto. The current flows through the conductive fiber 22 and is transferred to the surface of the housing of the electric drive assembly 100, and then is conducted to the ground via the corresponding grounding wire connected to the housing of the electric drive assembly 100.
[0020] Based on the above configuration, the insulating cover 1 inside the electric drive assembly 100 can effectively block the shaft current from forming a closed loop, thereby blocking the electro-corrosion effect of high-frequency circulating current on the bearing. The conductive component 2 can facilitate the flow of accumulated current at the other end of the electric drive assembly 100. After passing through the conductive fiber 22, the current is finally discharged, forming a method of blocking at one end and conducting at the other, which can better protect the bearing of the electric drive assembly 100 and extend its service life. Compared with the method of using ceramic ball bearings, the cost is relatively lower, which is conducive to controlling the overall production cost of the electric drive assembly 100. Moreover, the conductive component 2 used to facilitate the flow of current is installed firmly and reliably and is easy and quick to disassemble and assemble, which can facilitate the replacement of the conductive component 2 and reduce maintenance difficulty and labor costs.
[0021] In this invention, the conductive fiber 22 is disposed on the other side of the column 21. The end of the electric drive shaft opposite to the insulating cover 1 is hollow. The end of the column 21 with the conductive fiber 22 passes through the hollow end of the electric drive shaft, and the conductive fiber 22 contacts the inner wall of the electric drive shaft. Based on this arrangement, effective contact between the conductive fiber 22 and the electric drive shaft can be ensured.
[0022] The electric drive assembly 100 specifically includes a motor and a reducer. A threaded hole 101 is located at the end of the reducer housing opposite to the motor. When the motor shaft 102 and the reducer input shaft 103 are integrally formed, the electric drive shaft is this integral shaft, with the hollow end being the end of the electric drive shaft located inside the reducer. The insulating cover 1 is located at the end of the electric drive shaft opposite to the conductive component 2. When the motor shaft 102 and the reducer input shaft 103 are separate components connected only by transmission, specifically, the input shaft 103 is hollow, and the insulating cover 1 is located at the end of the motor shaft 102 opposite to the input shaft 103.
[0023] like Figure 3 As shown, the conductive fiber 22 is provided with several bundles, and the several bundles of conductive fiber 22 are arranged circumferentially and / or axially at intervals on the side of the column 21 to ensure that the contact area between the conductive fiber 22 and the electric drive shaft is larger.
[0024] A limiting platform 23 is provided at one end of the column 21 with external thread 211. The width or diameter of the limiting platform 23 is larger than the diameter of the column 21, so that after the column 21 is threadedly connected to the threaded hole 101, the limiting platform 23 is located outside the housing of the electric drive assembly 100. Based on this setting, the limiting platform 23 can limit the maximum screw-in length of the column 21 on the one hand, and facilitate the setting of the sealing structure on the other hand.
[0025] The limiting platform 23 has an internal hexagonal hole 231 in the middle to facilitate the rotation of the conductive component 2 with an internal hexagonal wrench.
[0026] This utility model also includes a sealing ring. The side of the limiting platform 23 facing the housing of the electric drive assembly 100 is provided with an annular groove. The sealing ring is disposed in the annular groove and abuts against the housing of the electric drive assembly 100 to form a sealing structure between the limiting platform 23 and the housing of the electric drive assembly 100, preventing impurities from entering and oil from flowing out.
[0027] This invention also includes a wave spring, which is located inside the insulating cover 1. The wave spring is sleeved on the motor shaft and contacts the outer ring end face of the bearing located inside the insulating cover 1. Since the bearing is generally located at the shaft shoulder, the wave spring design can better adapt to the slight changes in axial dimension caused by the thermal expansion and contraction effect of the electric drive shaft.
[0028] like Figure 2As shown, the insulating cover 1 includes an insulating ring 11 and an insulating plate 12. The insulating plate 12 is disposed at one end of the insulating ring 11, and the through hole 121 is formed in the middle of the insulating plate 12. Based on this configuration, as... Figure 1 As shown, the insulating cover 1 not only provides effective isolation but also facilitates the installation of bearings in the corresponding positions.
[0029] A fixing plate 13 is provided on the side of the insulating ring 11 facing away from the insulating plate 12. The fixing plate 13 has a fixing hole 131 for fasteners such as bolts connected to the edge of the bearing mounting area to pass through. The fixing plate 13 and the fixing hole 131 facilitate the fixing of the insulating cover 1 to the bearing mounting area. Two fixing plates 13 are symmetrically arranged along the axis of the insulating ring 11 to improve the stability of the fixing of the insulating cover 1.
[0030] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.
[0031] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.
Claims
1. A current corrosion resistant structure for an electric drive assembly bearing, characterized in that, The device includes an insulating cover (1) and a conductive component (2). The insulating cover (1) is located inside the bearing mounting area at one end of the electric drive assembly (100). The bearing inside the electric drive assembly (100) at that end is located inside the insulating cover (1), and the end of the insulating cover (1) is provided with a through hole (121) through which the electric drive shaft passes. The housing end face at the other end of the electric drive assembly (100) is provided with a threaded hole (101). The conductive component (2) includes a column (21) and a conductive fiber (22). One side of the column (21) is provided with an external thread (211), and the conductive fiber (22) is located at the other end of the column (21). The column (21) is threadedly connected to the threaded hole (101). The end of the column (21) with the conductive fiber (22) is located inside the other end of the electric drive assembly (100), and the conductive fiber (22) is in contact with the electric drive shaft.
2. The anti-current corrosion structure for the bearing of the electric drive assembly as described in claim 1, characterized in that, The conductive fiber (22) is disposed on the other side of the column (21). The end of the electric drive shaft away from the insulating cover (1) is hollow. The end of the column (21) with the conductive fiber (22) passes through the hollow end of the electric drive shaft. The conductive fiber (22) is in contact with the inner wall of the electric drive shaft.
3. The anti-current corrosion structure for the bearing of the electric drive assembly as described in claim 2, characterized in that, The conductive fiber (22) has several bundles, and the bundles of conductive fibers (22) are arranged circumferentially and / or axially at intervals on the side of the column (21).
4. The anti-current corrosion structure for the bearing of the electric drive assembly as described in any one of claims 1-3, characterized in that, The column (21) has a limiting platform (23) at one end with an external thread (211). The width or diameter of the limiting platform (23) is greater than the diameter of the column (21). After the column (21) is threadedly connected to the threaded hole (101), the limiting platform (23) is located outside the housing of the electric drive assembly (100).
5. The anti-current corrosion structure for the bearing of the electric drive assembly as described in claim 4, characterized in that, The limiting platform (23) is provided with an internal hexagonal hole (231) in the middle, or the limiting platform (23) is hexagonal.
6. The anti-current corrosion structure for the bearing of the electric drive assembly as described in claim 4, characterized in that, It also includes a sealing ring, and the limiting platform (23) has an annular groove on the side facing the housing of the electric drive assembly (100), and the sealing ring is disposed in the annular groove and abuts against the housing of the electric drive assembly (100).
7. The anti-current corrosion structure for the bearing of the electric drive assembly as described in any one of claims 1-3, 5, and 6, characterized in that, It also includes a wave spring, which is located inside the insulating cover (1) and is sleeved on the motor shaft and contacts the outer ring end face of the bearing located inside the insulating cover (1).
8. The anti-current corrosion structure for the bearing of the electric drive assembly as described in any one of claims 1-3, 5, and 6, characterized in that, The insulating cover (1) includes an insulating ring (11) and an insulating plate (12). The insulating plate (12) is disposed at one end of the insulating ring (11), and the through hole (121) is opened in the middle of the insulating plate (12).
9. The anti-current corrosion structure for the bearing of the electric drive assembly as described in claim 8, characterized in that, A fixing plate (13) is provided on the side of the insulating ring (11) facing away from the insulating plate (12), and a fixing hole (131) is provided on the fixing plate (13).
10. The anti-current corrosion structure for the bearing of the electric drive assembly as described in claim 9, characterized in that, Two fixing plates (13) are symmetrically arranged along the axis of the insulating ring (11).