A conductive ring for motor shaft and a drive system of electric vehicle

Abstract

The embodiment of the present specification provides a kind of electric motor shaft conductive ring and electric car driving system, and the conductive ring includes mounting ring and multiple conductive pieces, motor shaft passes through mounting ring, and rotates in mounting ring, multiple conductive pieces first end are all installed in mounting ring, and the second end of conductive piece extends to the inside of mounting ring, to ensure that the second end of conductive piece can at least partially contact with motor shaft, multiple conductive pieces second end are all skewed to the rotation direction of motor shaft, so that the acute angle included angle between conductive piece and motor shaft is formed, to offset the deflection of the second end of conductive piece caused by motor shaft rotation. By the end of conductive piece close to motor shaft skewed to the rotation direction of motor shaft, so as to offset the deflection of the second end of conductive piece caused by motor shaft rotation, avoid the performance decline caused by fiber deflection, improve the use performance of conductive ring.

Description

Technical Field

[0001] This specification relates to the field of electric drive system technology for new energy vehicles, specifically to a conductive ring for a motor shaft and an electric vehicle drive system. Background Technology

[0002] With the booming development of the new energy vehicle industry, 800V technology, with its significant advantages such as fast charging and efficient energy transmission, is gradually becoming the mainstream technology development direction in the industry and is being increasingly widely adopted. However, with the significant increase in voltage level, the drive system of new energy vehicles faces new technical challenges. In the drive motor system of new energy vehicles, the motor rotor generates an induced voltage during high-speed rotation due to the principle of electromagnetic induction. With the introduction of 800V technology, the operating voltage of the motor has increased significantly, and the induced voltage generated by the rotor has also risen sharply.

[0003] As a key component supporting rotor rotation and ensuring normal motor operation, motor bearings typically contain an internal oil film. Under normal operating conditions, this oil film provides insulation, preventing accumulated rotor charge from being directly conducted to other bearing components. However, when the rotor induced voltage is too high, the electric field strength borne by the oil film in the bearing increases significantly. When the oil film fails to meet effective insulation requirements, the accumulated charge energy of the rotor is released instantaneously. This energy release forms an electric arc upon breaking down the insulating oil film. The high temperature and energy of the arc cause severe damage to the bearing balls and raceways. Once the bearing balls or raceways are damaged by the arc, these damaged areas become weak points in the entire bearing oil film. During subsequent motor operation, the charge is more likely to break down the oil film at these weak points, forming an electric arc and further exacerbating the damage to the bearing. This vicious cycle leads to an increasing frequency of bearing arc damage, significantly accelerating bearing failure, severely impacting the motor's lifespan and reliability, and ultimately threatening the performance and safety of the entire power system of new energy vehicles.

[0004] Existing bearing protection solutions involve establishing a shaft voltage discharge channel outside the bearing to reduce voltage and protect it from electro-corrosion, thereby extending its service life. For example, prior art (CN217643069U) discloses a fiber retainer, a bearing electro-corrosion protection conductive ring, and a motor, where the fiber retainer is mounted on a bracket to protect the motor shaft.

[0005] However, the widely used fiber-based conductive rings have revealed a problem that urgently needs to be addressed in practical applications. During motor shaft rotation, the fibers in the conductive ring are subjected to various forces, such as centrifugal force and friction, causing the fibers to generally oscillate in one direction. With prolonged continuous motor operation and the inevitable thermal cycling during operation, this oscillation is further exacerbated. Specifically, the fibers deflect at a certain angle along the motor's rotation direction and are unlikely to return to their original position during subsequent operation. This fiber deflection phenomenon leads to a series of serious consequences. First, after the fibers deflect, their originally designed wear length is significantly shortened. In the design of conductive rings, the wear length is precisely calculated and optimized to ensure uniform wear throughout the entire service life, thereby guaranteeing stable conductivity. The shortened wear length leads to increased localized wear of the conductive ring, reducing its overall service life. Second, the bonding strength between the fibers and the motor shaft also decreases. Good overlap is key to ensuring stable current transmission. After the fiber deflects, the contact area between it and the motor shaft decreases and the contact pressure distribution becomes uneven, which leads to increased contact resistance and causes problems such as overheating and arcing. This seriously affects the conductivity of the conductive ring and may even threaten the safety and stability of the entire motor system. Summary of the Invention

[0006] In view of this, the embodiments of this specification provide a conductive ring for a motor shaft and a tram drive system, which deflects the end of the conductive component near the motor shaft toward the direction of motor shaft rotation, thereby counteracting the sway of the second end of the conductive component caused by the rotation of the motor shaft, avoiding the performance degradation caused by fiber deflection, and improving the performance of the conductive ring.

[0007] This specification provides the following technical solution in its embodiments: a conductive ring for a motor shaft, comprising a mounting ring and a plurality of conductive elements, wherein the motor shaft passes through the mounting ring and rotates within the mounting ring, the first ends of the plurality of conductive elements are all mounted within the mounting ring, and the second ends of the conductive elements extend to the inner side of the mounting ring to ensure that at least part of the second ends of the conductive elements can contact the motor shaft, and the second ends of the plurality of conductive elements are all deflected toward the rotation direction of the motor shaft, so that an acute angle is formed between the conductive elements and the motor shaft to counteract the sway of the second ends of the conductive elements caused by the rotation of the motor shaft.

[0008] Preferably, the conductive element includes conductive fibers, with a first end of the conductive fiber extending into the interior of the mounting ring and a second end of the conductive fiber extending into the inner side of the mounting ring and deflected in the direction of rotation of the motor shaft.

[0009] Preferably, the conductive element further includes a fiber retainer, which is at least partially installed within the mounting ring, and the first end of the conductive fiber is embedded within the fiber retainer.

[0010] Preferably, the extension direction of the fiber fixator is consistent with the orientation of the second end of the conductive fiber.

[0011] Preferably, the extension direction of the fiber fixator is not the same as the orientation of the second end of the conductive fiber.

[0012] Preferably, the mounting ring has a groove for mounting the fiber fixator, and the fiber fixator is at least partially embedded in the groove.

[0013] Preferably, the groove has a T-shaped cross-section, the fiber fixator includes a cylindrical structure, the first end of the conductive fiber is embedded in the cylindrical structure, and both ends of the cylindrical structure have limiting portions. The maximum width of the limiting portion is greater than the minimum width of the groove and less than the maximum width of the groove.

[0014] Preferably, the fiber retainer is riveted to the conductive fiber.

[0015] Preferably, the mounting ring includes a base ring and a cover ring, the first end of the conductive element is installed between the base ring and the cover ring, and the base ring and the cover ring are detachably and fixedly connected by a connector.

[0016] An electric vehicle drive system includes a conductive ring as described in any of the preceding claims, the conductive ring being disposed in the electric drive and arranged coaxially with the motor spindle or gearbox spindle.

[0017] Compared with the prior art, the beneficial effects that at least one technical solution adopted in the embodiments of this specification can achieve include at least:

[0018] By tilting the end of the conductive component closest to the motor shaft in the direction of motor shaft rotation, the sway of the second end of the conductive component caused by the rotation of the motor shaft is counteracted, thus avoiding performance degradation caused by fiber deflection and improving the performance of the conductive ring. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is an exploded view of the conductive ring for the motor shaft provided in this application;

[0021] Figure 2 This is a front view of the conductive ring for the motor shaft provided in this application;

[0022] Figure 3 This is a rear view of the conductive ring for the motor shaft provided in this application.

[0023] In the figure, 1 is the mounting ring; 101 is the cover ring; 102 is the base ring; 103 is the groove; 2 is the conductive component; 201 is the conductive fiber; 202 is the fiber retainer; 203 is the limiting part; and 3 is the connector. Detailed Implementation

[0024] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0025] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0027] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0028] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0029] Currently, during motor shaft operation, the fibers in fibrous conductive rings are subjected to various forces, such as centrifugal force and friction, causing the fibers to generally deflect in one direction. With prolonged continuous motor operation and the inevitable thermal cycles during operation, this deflection phenomenon is further exacerbated. Specifically, the fibers deflect at a certain angle along the motor's rotation direction and are unlikely to return to their original position during subsequent operation. This fiber deflection phenomenon leads to a series of serious consequences. First, after the fibers deflect, their originally designed wear length is significantly shortened. In the design of conductive rings, the wear length is precisely calculated and optimized to ensure uniform wear throughout the entire service life, thereby guaranteeing stable conductivity. The shortened wear length leads to increased localized wear of the conductive ring, reducing its overall service life. Second, the bonding strength between the fibers and the motor shaft also decreases. Good overlap is key to ensuring stable current transmission. After the fiber deflects, the contact area between it and the motor shaft decreases and the contact pressure distribution becomes uneven, which leads to increased contact resistance and causes problems such as overheating and arcing. This seriously affects the conductivity of the conductive ring and may even threaten the safety and stability of the entire motor system.

[0030] The technical solutions provided by the various embodiments of this application are described below with reference to the accompanying drawings.

[0031] like Figures 1-3 As shown, a conductive ring for a motor shaft includes a mounting ring 1 and a plurality of conductive elements 2. The motor shaft passes through the mounting ring 1 and rotates within the mounting ring 1. The first ends of the plurality of conductive elements 2 are all mounted within the mounting ring 1, and the second ends of the conductive elements 2 extend to the inner side of the mounting ring 1 to ensure that the second ends of the conductive elements 2 can at least partially contact the motor shaft. The second ends of the plurality of conductive elements 2 are all deflected towards the direction of rotation of the motor shaft, so that an acute angle is formed between the conductive elements 2 and the motor shaft to counteract the sway of the second ends of the conductive elements 2 caused by the rotation of the motor shaft.

[0032] The conductive ring for the motor shaft mainly consists of a mounting ring 1 and multiple conductive elements 2. The motor shaft passes through the mounting ring 1 and rotates within it. The first end of each conductive element 2 is fixedly mounted inside the mounting ring 1, while the second end extends to the inner side of the mounting ring 1, ensuring at least partial contact with the motor shaft. The second ends of the multiple conductive elements 2 are all deflected towards the direction of rotation of the motor shaft, forming an acute angle between the conductive element 2 and the motor shaft. This design cleverly utilizes the force generated when the motor shaft rotates, canceling out the sway of the second end of the conductive element 2 caused by the rotation of the motor shaft by the preset deflection angle. In other words, the conductive element 2 is pre-deflected towards the direction of rotation of the motor shaft, thereby maintaining stable contact with the motor shaft during actual operation and reducing performance degradation caused by deflection.

[0033] It should be noted that the above technical solution, through the skewed design of the conductive component 2, effectively counteracts the wobble of the second end of the conductive component 2 caused by the rotation of the motor shaft, thereby improving the fiber deflection problem of the conductive ring during use and enhancing the overall performance of the conductive ring. The acute angle formed between the conductive component 2 and the motor shaft ensures stable contact between the conductive component 2 and the motor shaft, maintaining good conductivity even after long-term operation and thermal cycling, reducing malfunctions caused by poor contact.

[0034] like Figure 1 As shown, in some embodiments, the conductive element 2 includes a conductive fiber 201. A first end of the conductive fiber 201 extends into the interior of the mounting ring 1, and a second end of the conductive fiber 201 extends into the inner side of the mounting ring 1, deflected towards the direction of rotation of the motor shaft. Specifically, the conductive element 2 includes a conductive fiber 201, with a first end extending into the interior of the mounting ring 1 and a second end extending into the inner side of the mounting ring 1, deflected towards the direction of rotation of the motor shaft. This deflection design ensures that when the motor shaft rotates, the second end of the conductive fiber 201 can contact the motor shaft in a predetermined manner.

[0035] It should be noted that in the specific preferred embodiment, the skew angle of the conductive fiber 201 is carefully calculated in order to counteract the swaying effect of the centrifugal force generated when the motor shaft rotates on the conductive fiber 201. Therefore, even when the motor shaft is rotating at high speed, the conductive fiber 201 can maintain stable contact with the motor shaft, ensuring good conductivity.

[0036] like Figure 1As shown, in some embodiments, the conductive element 2 further includes a fiber retainer 202, which is at least partially installed within the mounting ring 1. The first end of the conductive fiber 201 is embedded within the fiber retainer 202. The fiber retainer 202, at least partially installed within the mounting ring 1, is tightly coupled to the mounting ring 1 through a specific structure (such as grooves 103, snap-fits, etc.) to form a stable support base. The first end of the conductive fiber 201 is embedded within the fiber retainer 202, fixing the conductive fiber 201 relative to the fiber retainer 202. When the motor shaft rotates, the fiber retainer 202 acts as a stable support structure, maintaining the position of the conductive fiber 201 within the mounting ring 1. Simultaneously, the second end of the conductive fiber 201 (the portion skewed towards the direction of motor shaft rotation) maintains dynamic contact with the motor shaft, enabling current conduction. The use of the fiber retainer 202 significantly improves the stability of the conductive fiber 201 within the mounting ring 1. It effectively prevents the conductive fiber 201 from loosening or shifting during the rotation of the motor shaft, thus ensuring the continuous stability of conductivity. The precise fixation of the conductive fiber 201 by the fiber retainer 202 ensures good contact between the conductive fiber 201 and the motor shaft. This contact is not only stable but also reliable, contributing to improved conductivity of the conductive ring.

[0037] like Figures 1-3 As shown, in this embodiment, the extension direction of the fiber retainer 202 is consistent with the orientation of the second end of the conductive fiber 201. The alignment of the fiber retainer 202 with the second end of the conductive fiber 201 facilitates the connection between the conductive fiber 201 and the fiber retainer 202, and also facilitates the installation of the conductive component 2.

[0038] It should be noted that in some other embodiments, the extension direction of the fiber retainer 202 is not the same as the orientation of the second end of the conductive fiber 201. The design can be adjusted according to actual conditions, as long as the fiber retainer 202 can be installed inside the mounting ring 1, and the fiber retainer 202 and the conductive fiber 201 are mutually fixed, with the second end of the conductive fiber 201 tilted towards the direction of motor shaft rotation.

[0039] like Figure 1 As shown, in some embodiments, the mounting ring 1 has a groove 103 for mounting the fiber retainer 202, and the fiber retainer 202 is at least partially embedded in the groove 103. The groove 103 in the mounting ring 1 and the fiber retainer 202 form an interference fit structure. The fiber retainer 202 is at least partially embedded in the groove 103, ensuring that the fiber retainer 202 is fixed to the mounting ring 1. The centrifugal force generated by the rotation of the motor shaft is transmitted to the fiber retainer 202 through the conductive fiber 201, and is finally absorbed and dispersed by the sidewall of the groove 103, avoiding stress concentration that could cause fiber displacement.

[0040] like Figure 1 As shown, in some embodiments, the groove 103 has a T-shaped cross-section, and the fiber retainer 202 includes a cylindrical structure. The first end of the conductive fiber 201 is embedded in the cylindrical structure, and both ends of the cylindrical structure form limiting portions 203. The maximum width of the limiting portions 203 is greater than the minimum width of the groove 103, but less than the maximum width of the groove 103. The T-shaped groove 103 forms a geometric constraint with the limiting portions 203 of the fiber retainer 202 through its unique cross-sectional shape. When the cylindrical structure is embedded in the groove 103, the limiting portions 203 and the shoulder of the T-shaped groove form an axial lock, preventing the retainer from radially dislodging.

[0041] It should be noted that SMT placement equipment can be used to place the fiber retainer 202 components one-to-one into the groove 103.

[0042] like Figures 1-3 As shown, in some embodiments, the fiber retainer 202 and the conductive fiber 201 are riveted together. The riveting process causes plastic deformation of the fiber retainer 202 (typically made of metal), firmly clamping the conductive fiber 201 inside the fiber retainer 202, forming a mechanical interlocking structure between the fiber retainer 202 and the conductive fiber 201, ensuring the stability between the conductive fiber 201 and the fiber retainer 202.

[0043] like Figure 1 As shown, in some embodiments, the mounting ring 1 includes a base ring 102 and a cover ring 101. The first end of the conductive element 2 is installed between the base ring 102 and the cover ring 101. The base ring 102 and the cover ring 101 are detachably and fixedly connected by a connector 3. The mounting ring 1 is formed by the cooperation of the base ring 102 and the cover ring 101, and the first end of the conductive element 2 is installed between the base ring 102 and the cover ring 101 to ensure the relative fixation between the conductive element 2 and the mounting ring 1.

[0044] It should be noted that in this solution, the groove 103 can be formed on the base ring 102, and the base ring 102 and the cover ring 101 can be connected by bolts or screws.

[0045] Please see Figures 1-3 Based on the same inventive concept, embodiments of this specification provide an electric vehicle drive system, including a conductive ring as described in any of the above claims, wherein the conductive ring is disposed in the electric drive and arranged coaxially with the motor spindle or gearbox spindle.

[0046] In implementation, by adopting the aforementioned conductive ring and the skewed design of conductive component 2, the wobble at the second end of conductive component 2 caused by the rotation of the motor shaft is effectively counteracted, thereby improving the fiber deflection problem of the conductive ring during use and enhancing the overall performance of the conductive ring. The acute angle formed between conductive component 2 and the motor shaft ensures stable contact between conductive component 2 and the motor shaft, maintaining good conductivity even after long-term operation and thermal cycling, reducing malfunctions caused by poor contact.

[0047] It should be noted that the aforementioned conductive ring can also be applied to the fields of servo motor technology, high-power white goods, generators, and large-scale special machinery. Applications can be tailored to specific circumstances.

[0048] The same or similar parts between the various embodiments in this specification can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the method embodiments described later are relatively simple in description since they correspond to the system, and relevant parts can be referred to the descriptions in the system embodiments.

[0049] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A conductive ring for a motor shaft, comprising a mounting ring and a plurality of conductive elements, wherein the motor shaft passes through the mounting ring and rotates within the mounting ring, wherein first ends of the plurality of conductive elements are mounted within the mounting ring, and second ends of the conductive elements extend to the inner side of the mounting ring to ensure that at least partially, the second ends of the conductive elements can contact the motor shaft, characterized in that, The second ends of multiple conductive elements are all tilted toward the direction of rotation of the motor shaft, so that an acute angle is formed between the conductive elements and the motor shaft to counteract the sway of the second ends of the conductive elements caused by the rotation of the motor shaft.

2. The conductive ring for a motor shaft according to claim 1, characterized in that, The conductive component includes conductive fibers, with a first end of the conductive fiber extending into the interior of the mounting ring and a second end of the conductive fiber extending into the inner side of the mounting ring and deflected in the direction of rotation of the motor shaft.

3. The conductive ring for a motor shaft according to claim 2, characterized in that, The conductive component further includes a fiber retainer, which is at least partially installed within the mounting ring, with the first end of the conductive fiber embedded within the fiber retainer.

4. The conductive ring for a motor shaft according to claim 3, characterized in that, The extension direction of the fiber fixator is consistent with the orientation of the second end of the conductive fiber.

5. The conductive ring for a motor shaft according to claim 3, characterized in that, The extension direction of the fiber fixator is not the same as the orientation of the second end of the conductive fiber.

6. The conductive ring for a motor shaft according to claim 3, characterized in that, The mounting ring has a groove for mounting the fiber fixator, and the fiber fixator is at least partially embedded in the groove.

7. The conductive ring for a motor shaft according to claim 6, characterized in that, The groove has a T-shaped cross-section, and the fiber fixator includes a cylindrical structure. The first end of the conductive fiber is embedded in the cylindrical structure, and both ends of the cylindrical structure have limiting portions. The maximum width of the limiting portion is greater than the minimum width of the groove and less than the maximum width of the groove.

8. The conductive ring for a motor shaft according to claim 3, characterized in that, The fiber retainer is riveted and fixed to the conductive fiber.

9. The conductive ring for a motor shaft according to any one of claims 1-8, characterized in that, The mounting ring includes a base ring and a cover ring. The first end of the conductive element is installed between the base ring and the cover ring. The base ring and the cover ring are detachably and fixedly connected by a connector.

10. A tram drive system, characterized in that, Includes the conductive ring as described in any one of claims 1-9, wherein the conductive ring is disposed in an electric drive and arranged coaxially with the motor spindle or gearbox spindle.

Images