Motor shaft and motor comprising same
By setting grooves on the motor bearing mounting section and injection molding insulating components, the problem of electrical corrosion of drive motor bearings in new energy vehicles is solved, achieving low-cost electrical insulation and avoiding the problems of conductive carbon brush aging and high cost of ceramic bearings.
Patent Information
- Application Number
- CN202423094812.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-13
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2034-12-13
AI Technical Summary
Bearings in drive motors of new energy vehicles are prone to electro-corrosion under high power, high voltage, and high speed conditions. Existing technologies such as conductive carbon brushes are prone to aging, while ceramic bearings are difficult to process and costly.
A through groove is provided on the bearing mounting section of the motor shaft, and an insulating component is formed by injection molding to insulate the bearing from the motor shaft, reduce the potential difference, and prevent electro-corrosion.
It effectively reduces the risk of bearing electro-corrosion, has a simple manufacturing process and low cost, and avoids damage caused by spring aging.
Smart Images
Figure CN223729566U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to motor technical field especially is related to a kind of motor shaft and motor including the motor shaft of preventing bearing electric corrosion. BACKGROUND
[0002] New energy automobile drive motor has the characteristics of high power, high voltage, high speed and high frequency, and bearing electric corrosion occurs from time to time. Specifically, during the operation of the motor, a potential difference is formed between the inner ring and the outer ring of the bearing, i.e. shaft voltage. When the shaft voltage is low, the lubricating oil film on the bearing can exhibit insulation effect, and basically no shaft current occurs between the inner ring and the outer ring of the bearing. However, under high shaft voltage, the lubricating oil film is broken down, the inner ring and the outer ring of the bearing are electrically connected to form an electric current, causing local melting and unevenness of the contact surface, i.e. electric corrosion. The greater the power of the motor, the greater the risk of electric corrosion of its bearings.
[0003] In the prior art, one solution to electric corrosion is to install a conductive carbon brush, which is tightly engaged with the motor shaft by a spring on one side and connected to the motor housing to achieve grounding on the other side, thereby reducing the potential difference between the inner and outer rings of the bearing. However, the elasticity of the spring can easily age under long-term complex working conditions and environments, and can easily produce spring discharge, accelerating the damage of the bearing. Another solution is to use ceramic bearings, but ceramic bearings are difficult to process and have high cost compared to ordinary bearings. SUMMARY
[0004] The utility model aims to solve at least one of the above problems and / or other problems existing in the prior art.
[0005] To achieve the above-mentioned purpose, according to one aspect of the utility model, a motor shaft is provided, which comprises a rotor mounting section and two bearing mounting sections respectively arranged on both sides of the rotor mounting section. Each bearing mounting section is provided with a groove penetrating in the circumferential direction of the motor shaft on its outer peripheral surface, and an insulating member insulating the bearing from the motor shaft is formed in the groove by injection molding.
[0006] According to an embodiment of the utility model, the groove has a bottom wall, a first side wall close to the rotor mounting section and a second side wall away from the rotor mounting section.
[0007] According to an embodiment of the utility model, the outer diameter of the first side wall is greater than the inner diameter of the bearing, and the outer diameter of the second side wall is less than or equal to the inner diameter of the bearing.
[0008] According to an embodiment of the utility model, the insulating component comprises a cylindrical portion and a flange portion, the cylindrical portion extends along the axial direction of the motor shaft between the inner ring of the bearing and the bottom wall, and the flange portion extends outward along the radial direction of the motor shaft between the inner ring of the bearing and the first side wall of the groove.
[0009] According to an embodiment of the utility model, the bottom wall of the groove and the cylindrical portion of the insulating component are correspondingly provided with anti-rotation structures.
[0010] According to an embodiment of the utility model, the anti-rotation structures comprise anti-rotation cavities formed on the bottom wall and anti-rotation protrusions correspondingly formed on the inner circumferential surface of the cylindrical portion.
[0011] According to an embodiment of the utility model, the anti-rotation structures comprise a plurality of anti-rotation cavities and a plurality of anti-rotation protrusions arranged at intervals in the circumferential direction of the motor shaft.
[0012] According to an embodiment of the utility model, the motor shaft is provided with a stop portion extending outward along the radial direction of the motor shaft at a position adjacent to one of the bearing mounting sections of the rotor mounting section.
[0013] According to an embodiment of the utility model, the motor shaft further comprises a coupling portion arranged on the side of one of the bearing mounting sections away from the rotor mounting section.
[0014] According to another aspect of the utility model, a motor is provided, which comprises the motor shaft as described above.
[0015] The motor shaft of the utility model is provided with a groove at each bearing mounting section, and an insulating component is formed by injection molding in the groove, thereby effectively reducing the risk of bearing electric corrosion caused by current flowing between the inner ring of the bearing and the motor shaft. In addition, the utility model only needs to form the insulating component by injection molding between the inner ring of the bearing and the bearing mounting section of the motor shaft, so the manufacturing process is simple and the cost is low. BRIEF DESCRIPTION OF DRAWINGS
[0016] The features and advantages of the utility model will be clearly understood through the following detailed description with reference to the accompanying drawings. It should be understood that the following drawings are merely schematic and not necessarily drawn to scale, and therefore should not be considered as limiting the utility model, in which:
[0017] Figure 1 A perspective view of a motor shaft and two bearings thereof according to an embodiment of the utility model is shown.
[0018] Figure 2 A perspective view of a motor shaft and two bearings thereof according to an embodiment of the utility model is shown. Figure 1A cross-sectional view of the bearing mounting section of the left side of the motor shaft is shown with the corresponding bearing assembly.
[0019] Figure 3 An exploded view of the motor shaft is shown. Figure 1 An exploded view of the motor shaft is shown.
[0020] Figure 4 A cross-sectional view along the line A-A in Figure 3 A cross-sectional view along the line A-A in
[0021] Figure 5 An enlarged view of the circle B in Figure 4 An enlarged view of the circle B in
[0022] Figure 6 An enlarged view of the circle C in Figure 4 An enlarged view of the circle C in
[0023] BRIEF DESCRIPTION OF DRAWINGS
[0024] 1. rotor mounting section; 2. bearing mounting section; 3. groove; 31. bottom wall; 32. first side wall; 33. second side wall; 34. anti-rotation recess; 4. bearing; 5. insulating member; 51. cylindrical portion; 52. flange portion; 53. anti-rotation protrusion; 6. stop; 7. coupling portion. DETAILED DESCRIPTION
[0025] Embodiments of the present application are described herein below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. It will be apparent, however, to one skilled in the art, that the present application can be practiced without some or all of these specific details. In other instances, well known process steps and / or structures have not been described in detail in order to not unnecessarily obscure the present application. It will be understood that the present application is not limited in its application to the details set forth and that the present application is capable of implementation in other embodiments.
[0026] In the following description, terms such as "first", "second", etc. are used to describe various elements, and these terms are only used to distinguish one element from another, and are not used to limit the nature, order or number of the elements. The terms "include" and "have" are used to mean an open-ended inclusion, and refer to the presence of additional elements / components in addition to the listed elements / components.
[0027] Figures 1-6 A motor shaft according to one embodiment of the present application is shown. As Figures 1 to 3As shown, the motor shaft according to the embodiment can include a rotor mounting section 1 and two bearing mounting sections 2 integrally formed. The rotor mounting section 1 is located in the middle, and the two bearing mounting sections 2 are respectively arranged at the first end and the second end of the rotor mounting section 1 in the axial direction of the motor shaft.
[0028] Each bearing mounting section 2 is provided with a groove 3 penetrating in the circumferential direction of the motor shaft on its outer peripheral surface, and an insulating member 5 insulating the bearing 4 (more specifically, the inner ring of the bearing 4) from the motor shaft is formed in the groove 3 by injection molding.
[0029] The insulating member 5 can include a cylindrical portion 51 extending in the axial direction of the motor shaft and a flange portion 52 extending radially outward from one end of the cylindrical portion 51. Therefore, the inner ring of the bearing 4 can be insulated from the bearing mounting section 2 in both the axial and radial directions of the motor shaft, thereby avoiding the occurrence of shaft current between the inner and outer rings of the bearing 4, and thereby reducing the potential difference between the inner and outer rings of the bearing 4, thereby solving the problem of electrical corrosion of the bearing 4.
[0030] Figures 4 to 6 The cross-sectional view and the partial enlarged view of the motor shaft and the bearing of the embodiment in an exploded state are shown. In the following, the left bearing mounting section 2 and the corresponding bearing 4, insulating member 5 will be described in detail. Figure 1 、 Figure 3 and Figure 4 The left bearing mounting section 2 and the corresponding bearing 4, insulating member 5 will be described in detail.
[0031] As shown in Figure 5 , the groove 3 can include a bottom wall 31, a first side wall 32 and a second side wall 33. The bottom wall 31 is recessed radially inward from the outer periphery of the bearing mounting section 2. The first side wall 32 is formed on the side of the bottom wall 31 close to the rotor mounting section 1 (as shown on the right side). The second side wall 33 is formed on the side of the bottom wall 31 away from the rotor mounting section 1 (as shown on the left side). Figure 5 Figure 5
[0032] The outer diameter of the first side wall 32 is greater than the outer diameter of the second side wall 33. More specifically, the outer diameter of the first side wall 32 is greater than the inner diameter of the bearing 4, and the outer diameter of the second side wall 33 is less than or equal to the inner diameter of the bearing 4. Thus, the bearing 4 can pass through the outer periphery of the second side wall 33 and be stopped by the first side wall 32 at a position corresponding to the groove 3.
[0033] In combination with Figure 2 、 Figure 5 and Figure 6 As shown, the insulation member 5 can include a cylindrical portion 51 and a flange portion 52. The cylindrical portion 51 extends along the axial direction of the motor shaft between the inner ring of the bearing 4 and the bottom wall 31 of the groove 3, thereby insulating the inner ring of the bearing 4 from the bottom wall 31 of the groove 3. The flange portion 52 extends along the radial direction of the motor shaft outwardly from one end (the right end as shown) of the cylindrical portion 51 between the inner ring of the bearing 4 and the first side wall 32 of the groove 3, thereby insulating the inner ring of the bearing 4 from the first side wall 32 of the groove 3. Figure 6 As shown, the insulation member 5 can include a cylindrical portion 51 and a flange portion 52. The cylindrical portion 51 extends along the axial direction of the motor shaft between the inner ring of the bearing 4 and the bottom wall 31 of the groove 3, thereby insulating the inner ring of the bearing 4 from the bottom wall 31 of the groove 3. The flange portion 52 extends along the radial direction of the motor shaft outwardly from one end (the right end as shown) of the cylindrical portion 51 between the inner ring of the bearing 4 and the first side wall 32 of the groove 3, thereby insulating the inner ring of the bearing 4 from the first side wall 32 of the groove 3.
[0034] To prevent relative rotation between the insulation member 5 and the bearing mounting section 2 after injection molding, with reference to Figure 2 , Figure 5 and Figure 6 as shown, anti-rotation structures are correspondingly provided on the bottom wall 31 of the groove 3 and the cylindrical portion 51 of the insulation member 5.
[0035] Specifically, as shown in Figure 5 , the anti-rotation structures can include anti-rotation cavities 34 formed on the bottom wall 31, which are further recessed inwardly along the radial direction of the motor shaft from the outer circumferential surface of the bottom wall 31. Correspondingly, the injection-molded insulation member 5 has anti-rotation protrusions 53 formed on the inner circumferential wall of the cylindrical portion 51 thereof, which protrude inwardly along the radial direction of the motor shaft, as shown in Figure 6 . The anti-rotation protrusions 53 cooperate with the anti-rotation cavities 34 to prevent relative rotation between the insulation member 5 and the motor shaft.
[0036] In the illustrated embodiment, the bottom wall 31 of the groove 3 is provided with four anti-rotation cavities 34 at uniform intervals of 90° in the circumferential direction of the motor shaft, and the cylindrical portion 51 of the insulation member 5 is correspondingly provided with four anti-rotation protrusions 53. It can be understood that the number of anti-rotation cavities 34 and anti-rotation protrusions 53 is not limited to four, but can also be three, two, or even only one.
[0037] In another embodiment, the anti-rotation structures can include anti-rotation protrusions formed on the bottom wall 31 of the groove 3, and anti-rotation cavities correspondingly formed on the inner circumferential wall of the cylindrical portion 51 of the insulation member 5.
[0038] With reference to Figure 1 and Figure 3 , the motor shaft is provided with a stop portion 6 extending outwardly along the radial direction of the motor shaft at the portion of the bearing mounting section 2 adjacent to the left side of the rotor mounting section 1. When the rotor is sleeved onto the motor shaft from the right side in the figure, the left end surface of the rotor can abut against the stop portion 6. Thus, the rotor is limited to a specified position of the rotor mounting section 1. Obviously, the stop portion 6 can also be provided at the portion of the bearing mounting section 2 adjacent to the right side of the rotor mounting section 1.
[0039] Optionally, the motor shaft can further include a stop portion 6' extending outwardly along the radial direction of the motor shaft at the portion of the bearing mounting section 2 adjacent to the right side of the rotor mounting section 1, as shown in Figure 1 andFigure 3 A coupling portion 7 is shown in the middle. The coupling portion 7 is provided on the side of one of the bearing mounting sections 2 facing away from the rotor mounting section 1. The coupling portion 7 can be used to couple with an input shaft (in the case of the electric machine operating as a generator) or an output shaft (in the case of the electric machine operating as a motor), not shown. For example, the coupling portion 7 can be a spline. Figure 1 and Figure 3 In the embodiment shown, the stop portion 6 is provided on the left-hand side of the rotor mounting section 1 and the coupling portion 7 is provided on the right-hand end of the rotor mounting section 1. That is, the coupling portion 7 and the stop portion 6 are provided on opposite sides of the rotor mounting section 1. In further embodiments, the coupling portion 7 and the stop portion 6 can also be provided on the same side of the rotor mounting section 1.
[0040] The utility model also provides a motor including the motor shaft.
[0041] As described above, the motor shaft according to the utility model is formed with a groove 3 at each bearing mounting section 2, and an insulating member 5 is injection molded in the groove 3. The insulating member 5 effectively blocks the current between the inner ring of the bearing and the motor shaft, reducing the risk of electrical corrosion of the bearing 4. The insulating member 5 is formed between the inner ring of the bearing 4 and the bearing mounting section 2 of the motor shaft by injection molding, which is simple in manufacturing process and low in cost.
[0042] Various modifications and variations to the disclosed embodiments of the present utility model can be made without departing from the scope or spirit of the present utility model. Other embodiments of the present utility model will be apparent from consideration of the specification and practice of the present utility model disclosed herein. It is intended that the specification and examples be considered as illustrative only, with the true scope of the present utility model being indicated by the following claims and their equivalents.
Claims
1. An electric machine shaft comprising a rotor mounting section (1) and two bearing mounting sections (2) provided on both sides of the rotor mounting section (1), respectively, characterized in that, each of the bearing mounting sections (2) is provided with a groove (3) penetrating in the circumferential direction of the electric machine shaft on its outer peripheral surface, and an insulating member (5) for insulating a bearing (4) from the electric machine shaft is formed in the groove (3) by injection molding.
2. The electric machine shaft according to claim 1, characterized in that, the groove (3) has a bottom wall (31), a first side wall (32) close to the rotor mounting section (1), and a second side wall (33) away from the rotor mounting section (1).
3. The electric machine shaft according to claim 2, characterized in that, an outer diameter of the first side wall (32) is larger than an inner diameter of the bearing (4), and an outer diameter of the second side wall (33) is smaller than or equal to the inner diameter of the bearing (4).
4. The electric machine shaft according to claim 3, characterized in that, the insulating member (5) includes a cylindrical portion (51) extending in the axial direction of the electric machine shaft between an inner ring of the bearing (4) and the bottom wall (31) of the groove (3), and a flange portion (52) extending outward in the radial direction of the electric machine shaft between the inner ring of the bearing (4) and the first side wall (32) of the groove (3).
5. The electric machine shaft according to claim 4, characterized in that, anti-rotation structures are formed correspondingly on the bottom wall (31) of the groove (3) and the cylindrical portion (51) of the insulating member (5).
6. The electric machine shaft according to claim 5, characterized in that, the anti-rotation structures include anti-rotation recesses (34) formed on the bottom wall (31) and anti-rotation protrusions (53) formed correspondingly on an inner peripheral surface of the cylindrical portion (51).
7. The electric machine shaft according to claim 6, characterized in that, the anti-rotation structures include a plurality of anti-rotation recesses (34) and a plurality of anti-rotation protrusions (53) arranged at intervals in the circumferential direction of the electric machine shaft.
8. The electric machine shaft according to any one of claims 1 to 7, characterized in that, the electric machine shaft is provided with a stopper (6) extending outward in the radial direction of the electric machine shaft at a portion of the rotor mounting section (1) adjacent to one of the bearing mounting sections (2).
9. The electric machine shaft according to any one of claims 1 to 7, characterized in that, the electric machine shaft further comprises a coupling portion (7) provided on a side of one of the bearing mounting sections (2) away from the rotor mounting section (1).
10. An electric machine, characterized in that, the electric machine comprises the electric machine shaft according to any one of claims 1 to 9.