Motor shaft current elimination mechanism and motor

Abstract

The utility model belongs to the technical field of motor manufacturing, and especially relates to a motor shaft current elimination mechanism and a motor, the motor shaft current elimination mechanism comprises a motor shaft, two ends of the motor shaft are respectively a first end and a second end, the first end of the motor shaft is rotatably connected with a reduction gearbox housing, and the second end of the motor shaft is sleeved with an insulation bearing; the fixing shell is arranged between the first end and the second end of the motor shaft and is close to the reduction gearbox shell, the motor shaft is rotationally connected with the fixing shell through a middle supporting bearing, and the fixing shell is provided with a grounding end; and the conductive assembly comprises a conductor, the motor shaft is sleeved with the conductor, and the conductor is directly or indirectly connected between the fixing shell and the motor shaft, so that shaft current on the motor shaft is transmitted to the grounding end of the fixing shell through the conductor. According to the utility model, the shaft current on the motor shaft can be dredged out, so that the bearing electrocorrosion condition caused by the shaft current is avoided, the motor bearing is protected from being damaged, and the service life of the bearing is prolonged.

Description

Technical Field

[0001] This utility model belongs to the field of motor manufacturing technology, and in particular relates to a motor shaft current elimination mechanism and a motor. Background Technology

[0002] During operation, electric motors in new energy vehicles encounter various factors that can lead to shaft voltage. These factors primarily include electromagnetic imbalance, harmonic components in the power supply current, electrostatic effects, and interference from external power sources. These factors work together to create a potential difference between the motor stator and rotor, i.e., shaft voltage. Once formed, shaft voltage often creates a closed loop through the motor bearings, generating shaft current. During motor operation, the presence of shaft current can leave electro-corrosion marks on the inner and outer raceways of the bearings. These marks damage the smoothness of the bearing surface, increase frictional resistance, and not only lead to increased bearing temperature and motor operating noise, but also reduce the lifespan of both the bearings and the motor, ultimately increasing overall maintenance costs.

[0003] Therefore, for the design of motors in new energy vehicles, it is essential to fully consider and take measures to suppress the generation of shaft current in order to reduce or eliminate it. This helps ensure the long-term stable operation of the motor, reduce maintenance costs, thereby guaranteeing the normal operating life of the bearings and motor, and improving the performance and reliability of the entire vehicle. Utility Model Content

[0004] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a motor shaft current elimination mechanism and a motor, so as to solve the technical problem that the service life of motor bearings is affected by bearing electro-corrosion caused by shaft current in the prior art.

[0005] To achieve the above and other related objectives, the technical solution of this utility model is as follows:

[0006] A motor shaft current elimination mechanism, comprising:

[0007] The motor shaft has a first end and a second end at its two ends. The first end of the motor shaft is rotatably connected to the gearbox housing, and the second end of the motor shaft is fitted with an insulated bearing.

[0008] A fixed housing is disposed between the first end and the second end of the motor shaft and adjacent to the gearbox housing. The motor shaft is rotatably connected to the fixed housing through a central support bearing. The fixed housing has a grounding end.

[0009] A conductive component includes a conductor, which is sleeved outside the motor shaft and directly or indirectly connected between the fixed housing and the motor shaft, so that the shaft current on the motor shaft is transmitted to the grounding terminal of the fixed housing through the conductor.

[0010] Optionally, the conductive component has an axial gap with the central support bearing, and the conductive component is located on the side of the central support bearing facing the insulating bearing; or, the conductive component is located on the side of the central support bearing facing the gearbox housing.

[0011] Optionally, a positioning shoulder is provided on the outer peripheral wall of the motor shaft, and the conductive component is separated from the central support bearing by the positioning shoulder.

[0012] Optionally, the conductive component further includes a connecting sleeve, the conductor is sleeved on the outside of the connecting sleeve, the connecting sleeve is sleeved on the motor shaft and detachably connected to the motor shaft; or, the connecting sleeve is integrally formed with the outer peripheral wall of the motor shaft.

[0013] Optionally, the outer periphery of the conductor is fixedly mounted on the inner wall of the fixed shell, and the inner edge of the conductor is in contact with the connecting sleeve.

[0014] Optionally, the conductor includes a ring portion and a plurality of conductive brushes disposed circumferentially on the ring portion, wherein the fixed end of the conductive brush is connected to the ring portion, and the free end of the conductive brush extends radially inward along the ring portion.

[0015] Optionally, the outer diameter of the ring body is interference-fitted with the inner wall of the fixed shell, and the free end of the conductive brush abuts against the outer wall of the connecting sleeve.

[0016] Optionally, the conductive brush is a bundle of conductive fibers.

[0017] Optionally, it also includes a gearbox support bearing, which is disposed between the outer peripheral wall of the first end of the motor shaft and the inner peripheral wall of the gearbox housing, and the middle support bearing is located between the gearbox support bearing and the insulating bearing.

[0018] Based on the same concept, this utility model also provides a motor, including the motor shaft current elimination mechanism as described above.

[0019] As described above, the motor shaft current elimination mechanism and motor of this utility model have the following beneficial effects:

[0020] By installing an insulated bearing at the second end of the motor shaft, damage to the motor bearing from shaft current can be prevented. By installing a fixed shell adjacent to the gearbox housing between the first and second ends of the motor shaft, and installing conductors connected to the motor shaft and the fixed shell respectively, the shaft current on the motor shaft can be conducted to the fixed shell through the conductors and discharged from the grounding terminal of the fixed shell. This avoids bearing electro-corrosion caused by shaft current, protects the motor bearing from damage, and increases the bearing's service life. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the motor shaft current elimination mechanism according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of the conductor in an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures

[0024] 1-Gearbox housing; 11-Connecting part;

[0025] 2- Gearbox support bearing;

[0026] 3-Motor shaft; 31-Mounting cavity; 32-Positioning shoulder;

[0027] 4-Central support bearing;

[0028] 5-Fixed shell;

[0029] 6-Conductive component; 61-Conductor; 611-Ring body; 612-Conductive brush; 62-Connecting sleeve;

[0030] 7-Insulated bearings;

[0031] 8-Motor end cover. Detailed Implementation

[0032] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.

[0033] It should be noted that the illustrations provided in this embodiment are merely schematic representations of the basic concept of this utility model. Therefore, the illustrations only show components relevant to this utility model and are not drawn according to the actual number, shape, and size of the components in implementation. In actual implementation, the form, quantity, and proportion of each component can be arbitrarily changed, and the component layout may be more complex. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes and to assist those skilled in the art in understanding and reading the content disclosed in the specification. They are not intended to limit the implementation conditions of this utility model and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this utility model, should still fall within the scope of the technical content disclosed in this utility model. Meanwhile, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of implementation of this utility model.

[0034] In order to describe this utility model in detail, the motor shaft current elimination mechanism of this utility model will be specifically described below:

[0035] Please combine Figure 1 As shown, this utility model provides a motor shaft current elimination mechanism, including: a motor shaft 3, a fixed housing 5, and a conductive component 6. The motor shaft 3 has a first end and a second end, respectively. The first end of the motor shaft 3 is rotatably connected to a gearbox housing 1, and the second end of the motor shaft 3 is fitted with an insulating bearing 7. The fixed housing 5 is disposed between the first and second ends of the motor shaft 3 and adjacent to the gearbox housing 1. The motor shaft 3 is rotatably connected to the fixed housing 5 via a central support bearing 4. The fixed housing 5 has a grounding end. The conductive component 6 includes a conductor 61, which is fitted around the motor shaft 3 and directly or indirectly connected between the fixed housing 5 and the motor shaft 3, so that the shaft current on the motor shaft 3 is transmitted to the grounding end of the fixed housing 5 via the conductor 61.

[0036] Specifically, the first and second ends of the motor shaft 3 are merely for illustrative purposes and are not strictly limited to the front and rear ends of the motor shaft 3 during use. The first end of the motor shaft 3 has an internal mounting cavity 31 extending axially along the motor shaft 3. The inner wall of the gearbox housing 1, facing the motor shaft 3, has a connecting part 11 that extends into the mounting cavity 31 and is fitted into it, facilitating the positioning of the motor shaft 3. An insulating bearing 7 is fitted onto the second end of the motor shaft 3. This insulating bearing 7 prevents shaft current from damaging the bearing at the motor end, thus blocking the path of shaft current flowing directly to other components through the motor shaft 3, thereby initially achieving shaft current isolation. The insulating bearing 7 can take various forms, such as ceramic ball bearings, insulating coated bearings, bearings with insulated bearing housings, bearings with ceramic coatings on the inner / outer rings, or bearings with insulated inner / outer rings, etc.

[0037] A fixed housing 5 is disposed between the first and second ends of the motor shaft 3 and adjacent to the gearbox housing 1. The fixed housing 5 is used to fix the motor stator. The motor shaft 3 is rotatably inserted into the fixed housing 5 and is rotatably connected to the fixed housing 5 via a central support bearing 4. A conductor 61 is sleeved on the outside of the motor shaft 3 and located inside the fixed housing 5, and is directly or indirectly connected between the inner wall of the fixed housing 5 and the outer wall of the motor shaft 3. This conductor 61 conducts the shaft current on the motor shaft 3 to the fixed housing 5 through the conductor 61, and then conducts it away through the grounding terminal of the fixed housing 5. This achieves the conduction of the shaft current on the motor shaft 3, thereby protecting the motor bearing from damage.

[0038] By installing an insulating bearing 7 at the second end of the motor shaft 3 to block the shaft current, and installing a fixed shell 5 between the first and second ends of the motor shaft 3, and installing conductive bodies 61 connected to the motor shaft 3 and the fixed shell 5 respectively to conduct the shaft current, the "blocking and conducting" is achieved, ensuring the effective elimination of the motor shaft current, thereby preventing damage to the motor and connected components by the shaft current, avoiding bearing electro-corrosion caused by the shaft current, extending the bearing service life, and thus improving the operational stability and reliability of the entire motor system; moreover, it saves product space, has strong assembly processability, low cost, and is easy to maintain and inspect in daily operation.

[0039] In some embodiments, the conductive component 6 has an axial gap with the central support bearing 4, and the conductive component 6 is located on the side of the central support bearing 4 facing the insulating bearing 7; or, the conductive component 6 is located on the side of the central support bearing 4 facing the gearbox housing 1. Specifically, the conductive component 6 has a certain axial gap with the central support bearing 4, which ensures that the conductive component 6 can independently and efficiently perform its current conduction function without affecting the normal operation of the central support bearing 4. In addition, when the conductive component 6 is located on the side of the central support bearing 4 facing the insulating bearing 7, it can more directly capture and conduct the shaft current generated on the motor shaft 3, thereby reducing the propagation path and accumulation risk of the shaft current. This layout is particularly suitable for situations where the shaft current generation location is close to the insulating bearing 7, and can more effectively prevent the shaft current from spreading to other parts of the motor. Furthermore, this layout is also more cost-effective, as it does not require an excessively large conductor 61; or, in other embodiments, the conductive component 6 can also be located on the side of the central support bearing 4 facing the gearbox housing 1, depending on the operating conditions.

[0040] Understandably, a positioning shoulder 32 is provided on the outer peripheral wall of the motor shaft 3, and the conductive component 6 and the central support bearing 4 are separated by the positioning shoulder 32. The positioning shoulder 32 provides an axial positioning point, ensuring that the conductive component 6 and the central support bearing 4 maintain a fixed relative position during installation, thereby avoiding problems such as poor current conduction or mechanical interference caused by positional deviations. Furthermore, the separation of the conductive component 6 and the central support bearing 4 by the positioning shoulder 32 also achieves effective isolation between them, preventing direct conduction of shaft current between the conductive component 6 and the central support bearing 4, avoiding potential current leakage or short circuit risks, and also protecting the central support bearing 4 from the influence of shaft current, extending its service life.

[0041] In the above embodiments, the conductive component 6 further includes a connecting sleeve 62, with the conductor 61 sleeved around the connecting sleeve 62. The connecting sleeve 62 is fitted onto the motor shaft 3 and detachably connected to the motor shaft 3; alternatively, the connecting sleeve 62 is integrally formed with the outer peripheral wall of the motor shaft 3. Specifically, the connecting sleeve 62 rotates synchronously with the motor shaft 3. See also... Figure 1The connecting sleeve 62 is a separate component, independently fitted onto the motor shaft 3. The conductor 61 is fitted onto the outside of the connecting sleeve 62, and the outer periphery of the conductor 61 is connected to the fixed shell 5. This structure allows the conductor 61 and the motor shaft 3 to be indirectly connected through the connecting sleeve 62, thereby achieving structural flexibility and detachability. This facilitates the installation of the conductor 61 and the connecting sleeve 62, as well as subsequent individual maintenance and replacement, reducing maintenance costs and time. Alternatively, in other embodiments, the connecting sleeve 62 can also be integrally formed with the outer peripheral wall of the motor shaft 3. The integral design reduces the contact resistance between the connecting sleeve 62 and the motor shaft 3, improves conductivity, allows current to be transmitted more smoothly through the conductor 61 to the motor shaft 3, and reduces the number of parts and assembly steps, thus lowering maintenance costs.

[0042] In some embodiments, the outer periphery of the conductor 61 is fixedly engaged with the inner wall of the fixed housing 5, and the inner edge of the conductor 61 contacts the connecting sleeve 62. Specifically, the outer periphery of the conductor 61 is fixedly engaged with the inner wall of the fixed housing 5, ensuring that the conductor 61 is fixed even when the motor shaft 3 rotates. This ensures the stability and reliability of the conductor 61 during motor operation, preventing loosening or detachment due to vibration or impact, and guaranteeing good contact between the conductor 61 and the fixed housing 5, thereby ensuring smooth transmission of shaft current. The inner edge of the conductor 61 contacts the outer periphery of the connecting sleeve 62, further ensuring shaft current transmission between the motor shaft 3 and the conductor 61, allowing the shaft current to be transmitted more effectively from the connecting sleeve 62 through the conductor 61 to the fixed housing 5.

[0043] See Figure 2In the above embodiment, the conductor 61 includes a ring portion 611 and a plurality of conductive brushes 612 arranged circumferentially on the ring portion 611. The fixed ends of the conductive brushes 612 are connected to the ring portion 611, and the free ends of the conductive brushes 612 extend radially inward along the ring portion 611. Specifically, the ring portion 611 serves as the main structure of the conductor 61, providing stable support for the entire conductor 61. The plurality of conductive brushes 612 are evenly distributed circumferentially along the ring portion 611, giving the conductor 61 a wider contact area in the radial direction, thereby improving the efficiency and stability of current transmission. The free ends of the conductive brushes 612 extend radially inward along the ring portion 611, allowing the conductive brushes 612 to fit more tightly against the outer wall of the connecting sleeve 62. The free ends of the conductive brushes 612 can maintain close contact with the contact surface of the motor shaft 3 or the connecting sleeve 62 as the motor shaft 3 rotates, thereby achieving stable current transmission. Multiple conductive brushes 612 can form better multi-point electrical contact, reduce contact resistance, and improve current transmission efficiency. The free ends of the conductive brushes 612 have a certain degree of elasticity and flexibility, which can adapt to the slight deformation or vibration that may occur during operation, ensuring that the conductor 61 and the motor shaft 3 or the connecting sleeve 62 always maintain good electrical contact, avoiding current transmission problems caused by poor contact.

[0044] Understandably, the outer wall of the ring portion 611 is interference-fitted with the inner wall of the fixed shell 5, and the free end of the conductive brush 612 abuts against the outer wall of the connecting sleeve 62. The interference fit between the outer wall of the ring portion 611 and the inner wall of the fixed shell 5 ensures that the ring portion 611 is tightly pressed into the fixed shell 5, preventing loosening or displacement within the fixed shell 5 and thus guaranteeing the stability and reliability of the conductor 61 during motor operation. The abutment between the free end of the conductive brush 612 and the outer wall of the connecting sleeve 62 enhances the electrical contact between the conductive brush 612 and the connecting sleeve 62, ensuring stable current transmission to the connecting sleeve 62 when current passes through the conductive brush 612, thereby achieving efficient energy transfer. Through the elasticity and adaptability of the conductive brush 612, it can closely conform to the outer wall of the connecting sleeve 62, ensuring good contact between the conductive brush 612 and the connecting sleeve 62 under different operating conditions, thereby improving the stability and reliability of the electrical contact.

[0045] For example, the conductive brush 612 is a conductive fiber bundle. Specifically, the conductive fiber bundle can be, for example, a carbon fiber bundle, a metallized fiber bundle, etc., and is not limited here. The high conductivity of the conductive fiber bundle allows the axial current to be smoothly transmitted to the ring body 611 through the conductive brush 612. Both carbon fiber bundles and metal fiber bundles have good wear resistance and durability, making the conductive brush 612 less prone to wear or damage during long-term use, thereby extending the service life of the conductor 61.

[0046] In other embodiments, the conductor 61 may also be a carbon brush or carbon fiber structure, which can also achieve the above-mentioned conductive effect, and is not limited here.

[0047] Understandable, please refer to Figure 1 The motor shaft current elimination mechanism further includes a gearbox support bearing 2, which is disposed between the outer peripheral wall of the first end of the motor shaft 3 and the inner peripheral wall of the gearbox housing 1. A middle support bearing 4 is located between the gearbox support bearing 2 and the insulating bearing 7. Specifically, the gearbox support bearing 2 supports the first end of the motor shaft 3, ensuring that the motor shaft 3 can be rotatably connected to the gearbox housing 1; the middle support bearing 4 is located between the gearbox support bearing 2 and the insulating bearing 7, sharing the load generated by the motor shaft 3 during rotation with the gearbox support bearing 2 and the insulating bearing 7, thereby enhancing the load-bearing capacity of the motor shaft 3.

[0048] In addition, the second end of the motor shaft 3 is rotatably connected to the motor end cover 8 via the insulating bearing 7. The motor end cover 8 is connected to the fixed housing 5. The insulating bearing 7, relying on its own electrical insulation properties, can effectively block the current path between the motor shaft 3 and the motor end cover 8, and prevent the generation of shaft current.

[0049] Based on the same concept, this utility model also provides a motor, including the motor shaft current elimination mechanism as described above.

[0050] In summary, the motor shaft current elimination mechanism and motor provided by this utility model can prevent shaft current from damaging the motor shaft 3 bearing by setting an insulating bearing 7 at the second end of the motor shaft 3; by setting a fixed shell 5 adjacent to the gearbox housing 1 between the first end and the second end of the motor shaft 3, and setting a conductor 61 connected to the motor shaft 3 and the fixed shell 5 respectively, the shaft current on the motor shaft 3 can be conducted to the fixed shell 5 through the conductor 61 and discharged from the grounding end of the fixed shell 5, thereby avoiding bearing electro-corrosion caused by shaft current, protecting the motor shaft 3 bearing from damage, and increasing the bearing service life.

[0051] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A motor shaft current elimination mechanism, characterized in that, include: The motor shaft has a first end and a second end at its two ends. The first end of the motor shaft is rotatably connected to the gearbox housing, and the second end of the motor shaft is fitted with an insulated bearing. A fixed housing is disposed between the first end and the second end of the motor shaft and adjacent to the gearbox housing. The motor shaft is rotatably connected to the fixed housing through a central support bearing. The fixed housing has a grounding end. A conductive component includes a conductor, which is sleeved outside the motor shaft and directly or indirectly connected between the fixed housing and the motor shaft, so that the shaft current on the motor shaft is transmitted to the grounding terminal of the fixed housing through the conductor.

2. The motor shaft current elimination mechanism according to claim 1, characterized in that, There is an axial gap between the conductive component and the central support bearing, and the conductive component is located on the side of the central support bearing facing the insulating bearing; or, the conductive component is located on the side of the central support bearing facing the gearbox housing.

3. The motor shaft current elimination mechanism according to claim 2, characterized in that, The outer peripheral wall of the motor shaft is provided with a positioning shoulder, and the conductive component is separated from the central support bearing by the positioning shoulder.

4. The motor shaft current elimination mechanism according to claim 1 or 2, characterized in that, The conductive component further includes a connecting sleeve, the conductor is sleeved on the outside of the connecting sleeve, the connecting sleeve is sleeved on the motor shaft and is detachably connected to the motor shaft; or, the connecting sleeve is integrally formed with the outer peripheral wall of the motor shaft.

5. The motor shaft current elimination mechanism according to claim 4, characterized in that, The outer periphery of the conductor is fixedly fastened to the inner wall of the fixed shell, and the inner edge of the conductor is in contact with the connecting sleeve.

6. The motor shaft current elimination mechanism according to claim 5, characterized in that, The conductor includes a ring body and a plurality of conductive brushes arranged circumferentially on the ring body. The fixed ends of the conductive brushes are connected to the ring body, and the free ends of the conductive brushes extend radially inward along the ring body.

7. The motor shaft current elimination mechanism according to claim 6, characterized in that, The outer wall of the ring body is press-fitted with the inner wall of the fixed shell, and the free end of the conductive brush abuts against the outer wall of the connecting sleeve.

8. The motor shaft current elimination mechanism according to claim 6 or 7, characterized in that, The conductive brush is a bundle of conductive fibers.

9. The motor shaft current elimination mechanism according to claim 1, characterized in that, It also includes a gearbox support bearing, which is disposed between the outer peripheral wall of the first end of the motor shaft and the inner peripheral wall of the gearbox housing, and the middle support bearing is located between the gearbox support bearing and the insulating bearing.

10. An electric motor, characterized in that, Includes the motor shaft current elimination mechanism as described in any one of claims 1-9.

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