Transmission, electric assembly and vehicle

Abstract

The transmission is suitable for being applied to a vehicle and comprises a transmission shaft and a conductive piece, a first electric contact end of the conductive piece is electrically connected to the transmission shaft, and a second electric contact end of the conductive piece is suitable for being electrically connected to a grounding point on a vehicle body of the vehicle. The transmission shaft is directly connected to the grounding point on the vehicle body of the vehicle through the conductive part, so that most of shaft current conducted to the transmission shaft from the motor is directly led out through the conductive part, the shaft current is prevented from causing electrocorrosion to a transmission bearing, and the service life of the bearing is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to the field of transmission and electric assembly technology. Background Art

[0002] With the development of the economy and society, new energy vehicles driven by motors are becoming more and more popular. When the motor is working, shaft current will be generated on the motor shaft. The shaft current will flow along the potential difference, which will not only cause electrical corrosion to the bearings in the motor, but also be transmitted to the transmission adapted to the motor, causing electrical corrosion to the bearings in the transmission, affecting the life of the bearings and directly affecting the working life of the transmission. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a transmission that can prevent bearings in the transmission from being corroded by electricity, thereby extending the life of the bearings and the transmission.

[0004] The present invention provides a transmission suitable for use on a vehicle, characterized in that it includes a transmission shaft and a conductive member, wherein a first electrical contact end of the conductive member is electrically connected to the transmission shaft, and a second electrical contact end of the conductive member is suitable for being electrically connected to a grounding point on the vehicle body.

[0005] According to the transmission of the present invention, by connecting the transmission shaft to the grounding point on the vehicle body with a conductive part, most of the current conducted from the motor to the transmission shaft is discharged through the conductive part, so that the current on the transmission shaft does not flow through the bearings, avoiding electrical corrosion of the bearings. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0007] Figure 1 It is a cross-sectional schematic diagram of the transmission structure of an embodiment of the present invention.

[0008] Figure 2 It is a schematic diagram of the appearance of the transmission part structure of an embodiment of the present invention.

[0009] Figure 3 Schematic diagram of the appearance of the bracket and conductive member of the transmission according to an embodiment of the present invention.

[0010] Figure 4 It is a schematic diagram of the outer shape of the boss on the transmission case according to an embodiment of the present invention.

[0011] Figure 5 It is a schematic end view of the first electrical contact end of the conductive member of the transmission according to an embodiment of the present invention.

[0012] Figure 6 It is a simplified schematic diagram of the structure of an electric assembly according to an embodiment of the present invention.

[0013] Figure 7 is the shaft current flow path of the electric powertrain according to the embodiment of the present invention.

[0014] Figure 8 This is the shaft current flow path of the electric powertrain in the related art.

[0015] Reference numerals:

[0016] 10-transmission shaft, 11-first transmission shaft, 12-second transmission shaft, 13-third transmission shaft

[0017] 20 conductive member, 21 conductive brush, 22 first conductive core, 221 mounting hole, 23 first insulating layer, 24 second conductive layer, 241 second conductive sublayer, 242 second insulating sublayer

[0018] 30-box, 31-boss, 311-through hole, 312-sealing groove, 313-card table, 314-card slot

[0019] 40-bracket, 41-through hole, 42-clip, 43-constraint slot, 44-clip foot

[0020] 50-Seals

[0021] 60-conductive ring

[0022] 70-Gear pair

[0023] 80-motor shaft

[0024] 90-Transmission bearing

[0025] 100-Body

[0026] 110-Motor housing

[0027] 120-ground wire DETAILED DESCRIPTION

[0028] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] In the description of the present invention, "first feature" or "second feature" may include one or more of the features.

[0031] In the description of the present invention, “a plurality of” means two or more, and “a number of” means one or more.

[0032] Motor-driven vehicles usually have a motor connected to a transmission to reduce speed and increase torque, and then transfer the motor's power to the wheels to drive the vehicle.

[0033] Due to the asymmetry of the magnetic and electrical circuits in the motor, magnetic flux asymmetry results, which induces shaft voltage at both ends of the motor shaft 80, generating shaft current. Alternatively, due to the static charge generated by friction between the motor rotor and the air during high-speed operation, the static charge gradually accumulates and forms shaft current, generating shaft current on the motor shaft 80. The shaft current on the motor shaft 80 is transmitted to the transmission shaft 10, which is connected to the motor shaft 80 and enters the transmission. The transmission shaft 10 is supported on the housing 30 via bearings, creating a potential difference between the transmission shaft 10 and the housing 30. When this potential difference exceeds the dielectric breakdown voltage of the lubricating oil film between the bearing rolling elements and the inner and outer rings, the current on the transmission shaft 10 flows sequentially through the bearing inner ring, rolling elements, and outer ring, generating concentrated discharge between the three. This causes localized high temperatures to form between the bearing inner ring, rolling elements, and outer ring for a short period of time, potentially causing local melting or even adhesion of the rolling elements and / or the material between the inner and outer rings, leading to bearing failure. Bearing electrical corrosion, as referred to in the present invention, refers to the bearing failure phenomenon caused by this shaft current.

[0034] Some related technologies only focus on the protection of the motor shaft 80 bearing. In order to prevent the motor shaft 80 bearing from being corroded by electricity, insulating bearings are used. The current transmitted from the motor shaft 80 to the transmission shaft 10 will form a voltage difference between the transmission shaft 10 and the transmission case 30. The current flows through the transmission bearing 90 and causes electrical corrosion to it. Figure 8 The current flow path on the transmission shaft 10 is: transmission shaft 10 → transmission bearing 90 → transmission case 30 → motor housing 110 → grounding wire 120 → vehicle body 100 .

[0035] In recent years, as the motor power supply voltage has gradually increased, some related technologies have focused on the electrical corrosion protection of the transmission bearing 90. This type of technology sets a conductive ring 60 between the transmission shaft 10 and the housing 30 to conduct the current on the transmission shaft 10 to the housing 30 through the conductive ring 60. However, a large amount of electric charge accumulates on the transmission housing 30 and is then conducted to the vehicle body 100 through the motor housing 110 and the grounding wire 120. The transmission path is long, and the efficiency of charge extraction on the transmission housing 30 and / or the motor housing 110 is low. The large amount of accumulated electric charge will still cause damage to the parts in the transmission and / or motor, such as bearings.

[0036] In order to avoid or minimize the degree of electrical corrosion of the transmission bearing 90, an embodiment of the present invention provides a transmission, such as Figures 1 to 7 , suitable for use in a vehicle, includes a transmission shaft 10 and a conductive member 20, a first electrical contact end of the conductive member 20 being electrically connected to the transmission shaft 10, and a second electrical contact end of the conductive member 20 being suitable for being electrically connected to a grounding point on a vehicle body 100.

[0037] It can be understood that the first electrical contact end of the conductive member 20 refers to one of its parts that can be used for electrical contact, and the second electrical contact end of the conductive member 20 refers to another part that can be used for electrical contact relative to the first electrical contact end. The current of the first electrical contact end can be conducted to the second electrical contact end through the conductive member 20.

[0038] It should also be understood that the ground point on vehicle body 100 refers to the potential reference zero point in electrical connections. By directing current to the ground zero point, electrical safety is achieved for an electrical system, such as a vehicle. It should be noted that because vehicle body 100 is a large, continuous metal structure and has some electrical contact with the ground (via tires, etc.), vehicle body 100 can be considered an equivalent ground point.

[0039] The transmission provided by the embodiment of the present invention connects the transmission shaft 10 to the ground point on the vehicle body 100 via the conductive member 20, so that the shaft current conducted by the motor to the transmission shaft 10 is conducted through the conductive member 20, thereby preventing the current on the transmission shaft 10 from flowing through the bearings, thereby avoiding electrical corrosion of the bearings. Figure 7 , the current flow path on the transmission shaft 10 is: transmission shaft 10 → conductive member 20 → vehicle body 100 .

[0040] Therefore, by using the conductive part 20 to directly conduct the current of the transmission shaft 10 to the grounding point on the vehicle, instead of conducting the shaft current on the transmission shaft 10 through the conductive ring 60 to the transmission case 30 and then conducting it to the grounding point on the vehicle, the efficiency of shaft current conduction is improved, thereby avoiding electrical corrosion of the transmission bearing 90, improving the bearing life, and thus improving the life of the transmission.

[0041] It should be noted that the second electrical contact end of the conductive member 20 is suitable for being electrically connected to a grounding point on the vehicle body 100, which means that it can be directly connected to a grounding point on the vehicle body 100, or it can be indirectly connected to a grounding point on the vehicle body 100, such as being connected to the grounding wire 120 of the motor, and then connected to the vehicle body 100.

[0042] An embodiment of the present invention provides a transmission, wherein there are multiple transmission shafts 10, and the multiple transmission shafts 10 are transmission-connected to each other, one of the transmission shafts 10 is suitable for transmission connection with the motor shaft 80, and the first electrical contact end of the conductive member 20 is electrically connected to at least one transmission shaft 10.

[0043] In this embodiment, Figure 6 As shown, to achieve multi-speed shifting, the transmission includes multiple transmission shafts 10. To achieve a single-speed shifting, it includes at least two transmission shafts 10. Each transmission shaft 10 is supported on the case 30 via transmission bearings 90. Power is transmitted between the multiple transmission shafts 10 through gear meshing. Without shaft current suppression or channeling measures, the current transmitted from the motor shaft 80 to the transmission shaft 10 connected thereto would form a current loop between each transmission shaft 10 and the case 30, potentially subjecting the transmission bearings 90 connected thereto to electrical corrosion. By electrically connecting the first electrical contact terminal of the conductive member 20 to at least one transmission shaft 10 and the second electrical contact terminal of the conductive member 20 to a ground point on the vehicle body 100, the shaft current on the transmission shaft 10 is directly directed through the conductive member 20 to the ground point on the vehicle body 100, thereby preventing electrical corrosion of the transmission bearings 90.

[0044] Optionally, the first electrical contact end of the conductive member 20 can be set to be electrically connected to a transmission shaft 10. In order to improve the current extraction efficiency and increase the bearing protection, the first electrical contact end of the conductive member 20 can be set to be electrically connected to two transmission shafts 10. Of course, the first electrical contact end of the conductive member 20 can also be set to be electrically connected to all transmission shafts 10 to fully protect the transmission bearing 90 from electrical corrosion.

[0045] In a transmission provided by an embodiment of the present invention, the conductive member 20 includes a conductive brush 21 disposed at the first electrical contact end, abutting the surface of the transmission shaft 10. The conductive brush 21 can be a conductive carbon fiber brush or a soft conductive material such as a carbon rod. Because the transmission shaft 10 is a rotating moving part, the soft conductive brush 21 is disposed at the first electrical contact end of the conductive member 20 to facilitate full contact between the rotating transmission shaft 10 and the conductive brush 21, ensuring good electrical conductivity.

[0046] It can be understood that the surface of the transmission shaft 10 includes a radial outer surface and an end surface. The conductive brush 21 can abut against the radial outer surface of the transmission shaft 10 and be electrically connected to the transmission shaft 10. The conductive brush 21 can also abut against the end surface of the transmission shaft 10 and be electrically connected to the transmission shaft 10.

[0047] In some implementations of the present invention, see Figure 1 The conductive brush 21 abuts the end face of the transmission shaft 10. Since the area between the two end faces of the transmission shaft 10 is usually assembled with transmission components such as gears and bearings, leaving an electrical connection area on the outer surface of the transmission shaft 10 for the conductive brush 21 to abut would increase the length of the transmission shaft 10. Therefore, abutting the conductive brush 21 against the end face of the transmission shaft 10 not only helps to reduce the length of the transmission shaft 10, but also facilitates the fixation of the conductive member 20 within the transmission case 30, making the transmission compact and the conductive structure simple.

[0048] In some embodiments of the present invention, see Figure 1 The conductive brush 21 is fixed to the first electrical contact end of the conductive member 20. The fixed connection between the conductive member 20 and the conductive brush 21 makes the current extraction process on the transmission shaft 10 more stable, and avoids loose connection and poor contact between the conductive member 20 and the conductive brush 21, which would result in the shaft current on the transmission shaft 10 being unable to be extracted from the conductive member 20 and cause electrical corrosion of the transmission bearing 90.

[0049] A transmission provided by an embodiment of the present invention is shown in FIG. Figure 1 The conductive member 20 includes a first conductive core 22 and a first insulating layer 23. The first electrical contact end of the conductive member 20 is located on the first conductive core 22, and the first insulating layer 23 is wrapped around the outside of the first conductive core. This arrangement allows the shaft current on the transmission shaft 10 to be conducted through the first conductive core 22 to the grounding point of the vehicle body 100. By wrapping the first insulating layer 23 around the first conductive core 22, interference with the shaft current conduction path is prevented, while also providing insulation protection for surrounding components, equipment, and personnel.

[0050] In some embodiments of the present invention, the conductive member 20 includes a conductive brush 21, and a mounting hole 221 is formed on the end surface of the first conductive core 22, and the conductive brush 21 is fixed in the mounting hole 221. Specifically, Figure 5 As shown, the end surface of the first conductive core 22 is provided with a plurality of mounting holes 221. One end of the conductive brush 21 bristle bundle is positioned in the mounting hole 221. Pressure can be applied radially from the outside to the inside of the first conductive core 22 to press-rivet the bristle bundle into the mounting hole 221. The other end, exposed from the end surface of the first conductive core 22, is free to abut against the surface of the transmission shaft 10 for electrical contact. This method of securing the bristles of the conductive brush 21 is simple and low-cost.

[0051] A transmission provided in an embodiment of the present invention, refer to 1, also includes a housing 30, a transmission shaft 10 is arranged on the inner side of the housing 30, and a through hole 311 is provided on the housing 30 that passes through the inner side and the outer side of the housing 30. The conductive member 20 is at least partially arranged in the through hole 311, the first electrical contact end is located on the inner side of the housing 30, and the second electrical contact end is located on the outer side of the housing 30.

[0052] It is understood that metal is typically used for the housing 30 due to its high load-bearing capacity, excellent mechanical properties, and high economic efficiency. Because the housing 30 is made of metal and is conductive, the current transmitted from the motor to the transmission shaft 10 forms a conductive path between the transmission shaft 10 and the housing 30, which can cause electrical corrosion to the bearings connected and supported between the transmission shaft 10 and the housing 30.

[0053] In this embodiment, the case 30 supports the transmission shaft 10 inside the case 30 via bearings, thereby providing support and protection for the transmission shaft 10 and internal transmission components. The case 30 is provided with a through hole 311 extending through both the inside and outside of the case 30. This allows the transmission shaft 10 inside the transmission case 30 to be electrically connected to a ground point on the vehicle body 100 outside the transmission case 30 via a conductive member 20. Specifically, the conductive member 20 is inserted into the through hole 311. The first electrical contact end of the conductive member 20 located inside the case 30 abuts against the transmission shaft 10, while the second electrical contact end located outside the case 30 is used to electrically connect to a ground point on the vehicle body 100.

[0054] It should be noted that the housing 30 and the through hole 311 in this embodiment can be actually set according to the power supply voltage of the motor matched with the transmission. If the power supply voltage of the motor is low, the shaft current is small, and the common conductive ring 60 solution can be used to protect the transmission bearing 90 from electrical corrosion, or the shaft current extraction measures at the motor end can be relied upon to protect the transmission bearing 90 from electrical corrosion. In other words, whether to open the through hole 311 on the housing 30 can be selected according to actual conditions. Specifically, during the processing of the housing 30, the through hole 311 can be set as a machined hole instead of a mold precast hole. This increases the versatility of the housing 30 and the transmission for both high-voltage and low-voltage motors, and avoids the structural complexity of setting a separate cover to seal the through hole 311 when the transmission is used on a low-voltage motor and the possibility of oil leakage in the housing 30.

[0055] A transmission provided by an embodiment of the present invention, referring to Figure 1 A seal 50 is provided between the outer surface of the conductive member 20 and the inner wall of the through-hole 311. The conductive member 20 is inserted into the through-hole 311 of the housing 30. A sealing groove 213 is provided on the inner wall of the through-hole 311. The seal 50 is disposed within the sealing groove 213. This seal is achieved between the conductive member 20 and the through-hole 311 of the housing 30 to prevent transmission oil leakage or foreign matter from entering the transmission, which could adversely affect transmission operation.

[0056] A transmission provided by an embodiment of the present invention includes a conductive ring 60 . The conductive ring 60 is sleeved on the speed-changing shaft. The transmission shaft 10 is electrically connected to the housing 30 via the conductive ring 60 .

[0057] As the supply voltage of new energy vehicle motors gradually increases, the threat posed by the current of motor shaft 80 to transmission bearing 90 becomes increasingly prominent. To effectively alleviate the problem of electrical corrosion of transmission bearing 90, in some embodiments, both a conductive member 20 and a conductive ring 60 can be provided on the transmission shaft 10. Specifically, the majority of the current conducted from the motor to the transmission shaft 10 is conducted through the conductive member 20, which has a lower resistivity, to a ground point on the vehicle body 100. The remaining portion of the current conducted from the motor to the transmission shaft 10 is conducted through the transmission shaft 10, the conductive ring 60, the transmission case 30, the motor housing 110, and the grounding wire 120 to a ground point on the vehicle body 100. By providing two shaft current conductive paths, the shaft current on the transmission shaft 10 is promptly and effectively conducted away, effectively preventing the shaft current from passing through the transmission bearing 90 and causing electrical corrosion there.

[0058] A transmission provided by an embodiment of the present invention includes a conductive ring 60, which is sleeved on the speed-changing shaft. The transmission shaft 10 is electrically connected to the housing 30 through the conductive ring 60. The conductive part 20 includes a first conductive core 22, a first insulating layer 23 and a second conductive layer 24. The first electrical contact end is located on the first conductive core 22. The second electrical contact end includes a first sub-end and a second sub-end. The first sub-end is located on the first conductive core 22, and the second sub-end is located on the second conductive layer 24. The first insulating layer 23 is coated on the outside of the first conductive core, and the second conductive layer 24 is coated on the outside of the first insulating layer 23. The second conductive layer 24 contacts the inner wall of the through hole 311.

[0059] like Figure 1 As shown, the conductive member 20 comprises a three-layer structure: from the inside out, a first conductive core 22, a first insulating layer 23, and a second conductive layer 24. A first electrical contact terminal, adapted for electrical connection to the transmission shaft 10, and a first sub-terminal, adapted for electrical connection to the ground point of the vehicle body 100, are located on the first conductive core 22. The second sub-terminal, adapted for electrical connection to the ground point of the vehicle body 100, is located on the second conductive layer 24. Consequently, the shaft current on the transmission shaft 10 forms a first flow path: transmission shaft 10 → first electrical contact terminal → first conductive core 22 → first sub-terminal → ground point of the vehicle body 100. The second conductive layer 24, separated by the first insulating layer 23, contacts the inner wall of the through-hole 311, forming a second flow path: transmission shaft 10 → conductive ring 60 → transmission case 30 → second conductive layer 24 → second sub-terminal → ground point of the vehicle body 100. By providing the first insulating layer 23 and the second conductive layer 24 in electrical contact with the inner wall of the through-hole 311, the conductive member 20 divides the shaft current on the transmission shaft 10 into two independent conduction paths, all of which are directed to the ground point of the vehicle body 100. This prevents some of the shaft current from being conducted through the conductive ring 60 to the transmission case 30, where it could accumulate charge and potentially cause secondary damage to components within the transmission. It is understood that the purpose of the first insulating layer 23 is to prevent interference between the first and second conductive paths, which could prevent the shaft current on the transmission shaft 10 from being effectively conducted.

[0060] In another embodiment of the present invention, the second conductive layer 24 includes a second conductive sublayer 241 and a second insulating sublayer 242. The second conductive sublayer 241 is coated on the outside of the first insulating layer 23. The second conductive sublayer 241 includes a first section and a second section connected to each other. The first section is at least partially located in the through hole 311, and the second section is located on the outside of the box body 30. The second insulating sublayer 242 is coated on the second section.

[0061] like Figure 1As shown, the portion of the conductive member 20 located within the through hole 311 comprises a three-layer structure from the inside out: a first conductive core 22, a first insulating layer 23, and a second conductive sublayer 241. The portion of the conductive member 20 located outside the through hole 311 comprises a four-layer structure from the inside out: a first conductive core 22, a first insulating layer 23, a second conductive sublayer 241, and a second insulating sublayer 242.

[0062] In the specific implementation process, the conductive part 20 can be a conductive wire, which includes a four-layer structure from the inside to the outside: a first conductive core 22, a first insulating layer 23, a second conductive sublayer 241, and a second insulating sublayer 242. The second insulating sublayer 242 of the conductive wire located in the through hole 311 can be removed to form the first section of the second conductive sublayer 241. This part of the conductive wire is inserted into the inner side of the box body 30 through the through hole 311, so that the first electrical contact end of the conductive wire is in contact with the transmission shaft 10, and it is ensured that the second conductive sublayer 241 exposed by removing the second insulating sublayer 242 of the conductive wire is in electrical contact with the inner wall of the through hole 311 of the box body 30.

[0063] The second insulating sublayer 242 is wrapped around the outside of the second section, that is, the second insulating sublayer 242 provides insulation protection for the conductive part 20 located outside the transmission case 30, preventing exposed live parts from causing damage to surrounding components, equipment and personnel.

[0064] It should be noted that the function of the second conductive sublayer 241 is to contact the inner wall of the through-hole 311 to form an electrical contact with the box body 30. Therefore, the outer portion of the conductive member 20 located in the through-hole 311 can be completely covered by the second conductive sublayer 241. In theory, the outer portion of the conductive member 20 located in the through-hole 311 can also be only partially covered by the second conductive sublayer 241. The conductive member 20 only needs to contact the inner wall of the through-hole 311 on the box body 30 through the second conductive sublayer 241 to form a conductive path. However, if only a portion of the outer portion of the second section is covered with the second conductive sublayer 241, the area of electrical contact with the inner wall of the through-hole 311 is reduced, and the reliability of the conductive path is poor. Therefore, it is preferred that the outer portion of the conductive member 20 located in the through-hole 311 is completely covered by the second conductive layer 24. In this embodiment, the outer diameter of the second conductive sublayer 241 can be set to be roughly equal to the outer diameter of the through hole 311, which facilitates the installation of the conductive part 20 in the through hole 311 while ensuring good contact between the second conductive sublayer 241 and the inner wall of the through hole 311, so that the second conductive path of the shaft current is effective and reliable.

[0065] A transmission provided by an embodiment of the present invention is shown in FIG. Figures 1 to 3, further comprising a bracket 40 connected to the outside of the housing 30. The conductive member 20 located outside the housing 30 is secured to the bracket 40. By securing the portion of the conductive member 20 located outside the housing 30 to the housing 30, the conductive member 20 and the transmission shaft 10 are prevented from losing contact due to vibration or other factors during vehicle operation, thereby disconnecting the current extraction path on the transmission shaft 10 and causing current extraction failure. The securing of the conductive member 20 by the bracket 40 improves the operational stability of the conductive member 20.

[0066] A transmission provided by an embodiment of the present invention is shown in FIG. Figure 1 and Figure 2 The housing 30 is provided with a boss 31 on its exterior, and a through-hole 311 extends through the end surface of the boss 31 and the inner wall of the housing 30. Considering the requirements for lightweighting vehicles and transmissions, the housing 30 is typically designed with a relatively small wall thickness. The through-hole 311, which extends through both the interior and exterior of the housing 30, is relatively shallow, and the inner wall area of the through-hole 311 is small. This results in a relatively small contact area between the outer surface of the conductive member 20 and the inner wall of the through-hole 311. This leads to insufficient or unstable contact between the conductive member 20 and the inner wall of the through-hole 311, affecting the conductive member 20's ability to extract shaft current from the transmission shaft 10. Specifically, this affects the conductive member 20's ability to extract shaft current from the second flow path (transmission shaft 10 → conductive ring 60 → transmission housing 30 → second conductive layer 24 → second sub-end → ground point on the vehicle body 100). Providing the boss 31 on the exterior of the housing 30 increases the contact area between the second conductive layer 24 and the through-hole 311, facilitating the conductive member 20's ability to consistently and stably extract shaft current from the transmission shaft 10.

[0067] It can also be understood that by providing a boss 31 on the box body 30, a through hole 311 passes through the end face of the boss 31 and the inner wall surface of the box body 30. Compared with the manner in which the through hole 311 passes through the outer surface and the inner wall surface of the box body 30, the length of the through hole 311 becomes longer, the conductive member 20 is partially passed through the through hole 311 and the first electrical contact end abuts against the surface of the transmission shaft 10, the limiting of the conductive member 20 is more stable, and the deformation and deflection of the conductive member 20 abutting against the rotating transmission shaft 10 during the high-speed rotation of the transmission shaft 10 can be reduced, thereby improving the stability of the contact between the first electrical contact end of the conductive member 20 and the surface of the transmission shaft 10, thereby improving the effect of the conductive member 20 in deriving the shaft current.

[0068] In some embodiments of the present invention, a clamping platform 313 is provided on the boss 31 of the box body 30, and the bracket 40 includes a buckle 42, and the bracket 40 is clamped on the clamping platform 313 through the buckle 42. Specifically, Figure 3As shown, the bracket 40 is provided with a through-hole 41, through which the conductive member 20 is inserted. The portion of the conductive member 20 located within the through-hole 311 and inside the housing 30 is on one side of the through-hole 41, while the portion of the conductive member 20 located outside the housing 30 is on the other side of the through-hole 41. The side of the bracket 40 closest to the housing 30 is attached to the end face of the boss 31. The through-hole 41 on the bracket 40 corresponds to the through-hole 311 on the boss 31, so that the first electrical contact end of the conductive member 20 passes through the through-hole 41 and the through-hole 311 in sequence, extends into the inside of the housing 30, and makes electrical contact with the transmission shaft 10. The bracket 40 includes two left and right clips 42 extending toward the housing 30. Two latches 313 are provided on either side of the boss 31. The two latches 313 correspond to the two clips 42 in a one-to-one manner, so that the clips 42 engage the latches 313 to secure the bracket 40 to the boss 31.

[0069] In some embodiments of the present invention, the two clips 42 on the bracket 40 and the two clamping platforms 313 on the boss 31 are symmetrically arranged, which is beneficial to the reliability of the clamping, the processing and forming of the boss 31 on the case 30, and the beautiful appearance of the transmission case 30 and the bracket 40.

[0070] In some embodiments of the present invention, the bracket 40 is further provided with a restraining groove 43, and the conductive member 20 is configured as a conductive wire, such as Figure 2 As shown, a portion of the conductive wire is positioned within a restraining groove 43 to secure and constrain the free portion between the first and second electrical contact terminals. This prevents the free portion from swaying and rubbing against surrounding components during vehicle operation, potentially damaging the wire's insulation and causing unnecessary electrical failures. Furthermore, the width of the restraining groove 43 on the bracket 40 is slightly smaller than the diameter of the conductive wire, allowing the conductive cable to be installed in the restraining groove 43 with an interference fit, thereby being constrained and fixed. This eliminates the need for additional fixing structures, resulting in simple and convenient installation and reliable restraint.

[0071] In some embodiments of the present invention, the bracket 40 also includes a clamping foot 44, and a clamping groove 314 is provided on the end face of the boss 31 of the box body 30. The clamping groove 314 and the through hole 311 are arranged at intervals. The distances between the mounting hole 221 on the bracket 40 and the clamping foot 44, and the through hole 311 on the boss 31 and the clamping groove 314 are equal, and the positions correspond one to one. While the bracket 40 is fixed to the boss 31 by the clamping foot 44, it is further limited in the clamping groove 314 by the clamping foot 44, thereby increasing the reliability of the bracket 40 fixing the conductive part 20, and also avoiding the bracket 40 from falling off instantly when the buckle 42 on the bracket 40 breaks, becomes abnormal, or other faults occur, causing the shaft current extraction path to be abnormal, or even the conductive part 20 to fall out.

[0072] In an embodiment of the present invention, a transmission shaft 10 includes a first transmission shaft 11, the first transmission shaft 11 is adapted to be coaxially connected to the motor shaft 80, and the first electrical contact end of the conductive member 20 is electrically connected to the first transmission shaft 11. Figure 6 In this embodiment, the first transmission shaft 11 and the motor shaft 80 are coaxially connected, meaning that the power output by the motor shaft 80 is directly transmitted to the first transmission shaft 11. Specifically, the first transmission shaft 11 and the motor shaft 80 may be connected via internal and external splines, or via a coupling. Regardless of the connection method, the first transmission shaft 11 and the motor shaft 80 are directly connected. During power transmission, the motor shaft 80 and the first transmission shaft 11 form a current transmission path, with the shaft current on the motor shaft 80 initially flowing to the first transmission shaft 11, or the majority of the shaft current on the motor shaft 80 flowing to the first transmission shaft 11. Consequently, the bearings between the first transmission shaft 11 and the housing 30 may be subject to severe electrical corrosion. The first electrical contact end of the conductive member 20 is electrically connected to the first transmission shaft 11, and the second electrical contact end is electrically connected to the grounding point on the vehicle body 100, so that most of the shaft current on the motor shaft 80 can be directly discharged to the grounding point on the vehicle body 100, thereby minimizing the electrical corrosion of the bearings on the first transmission shaft 11, and also reducing the electrical corrosion of the bearings on other transmission shafts 10 that are transmission-connected to the motor shaft 80.

[0073] like Figure 6 As shown, a transmission with three transmission shafts 10 is used as an example for explanation. The transmission includes a first transmission shaft 11, a second transmission shaft 12 and a third transmission shaft 13, and the first transmission shaft 11, the second transmission shaft 12 and the third transmission shaft 13 are all supported on the transmission case 30 through bearings. The motor shaft 80 is connected to the first transmission shaft 11, and the first transmission shaft 11 and the second transmission shaft 12 are meshed and connected through a gear pair 70. The second transmission shaft 12 and the third transmission shaft 13 are meshed and connected through a gear pair 70. If there is no shaft current diversion measure, the shaft current generated on the motor shaft 80 will form a conductive path between the first transmission shaft 11 and the case 30, between the second transmission shaft 12 and the case 30, and between the third transmission shaft 13 and the case 30, respectively, which will cause electrical corrosion to the bearings on the first transmission shaft 11, the second transmission shaft 12 and the third transmission shaft 13. The conductive member 20 is electrically connected to the first transmission shaft 11 to divert the shaft current on all current paths described below from the source, thereby protecting all bearings on the transmission shaft 10 from electrical corrosion or reducing the degree of electrical corrosion to the greatest extent.

[0074] Current path 1: motor shaft 80 → first transmission shaft 11 → housing 30

[0075] Current path 2: motor shaft 80 → first transmission shaft 11 → second transmission shaft 12 → housing 30

[0076] Current path 2: motor shaft 80 → first transmission shaft 11 → second transmission shaft 12 → third transmission shaft 13 → housing 30

[0077] By comparison, it can be seen that compared with the conductive member 20 being electrically connected to the second transmission shaft 12 and / or the third transmission shaft 13 , the conductive member 20 being electrically connected to the first transmission shaft 11 has the best protection effect on all bearings in the transmission.

[0078] A transmission provided by an embodiment of the present invention includes a housing 30, a transmission shaft 10, a conductive member 20, and multiple bearings. The number of transmission shafts 10 is multiple, and the multiple transmission shafts 10 are supported on the housing 30 by multiple bearings. The first electrical contact end of the conductive member 20 is electrically connected to one of the transmission shafts 10, and the second electrical contact end of the conductive member 20 is suitable for electrically connecting to a ground point on the vehicle body 100. At least one of the multiple bearings is an insulating bearing. In this embodiment, the shaft current on the transmission shaft 10 is extracted through the transmission shaft 10 connected to the conductive member 20. One or more bearings are insulating bearings. The insulating bearings block the conductive path between the transmission shaft 10 and the housing 30. The conductive member 20 connected to the transmission shaft 10 is connected to the ground point on the vehicle body 100, so that the shaft current is extracted through the conductive member 20 with lower resistivity, so that less current or no current passes through the bearings. This arrangement significantly reduces the risk of electrical corrosion of the transmission bearings 90, and the reliability and life of the transmission are improved.

[0079] Insulated bearings are self-insulating and do not form conductive paths. They can be made of insulating materials, such as ceramic bearings, or have an insulating coating sprayed on the surface of the bearing to achieve good insulation effect and prevent electric corrosion damage to the grease, rolling elements and raceways caused by current.

[0080] A transmission provided by an embodiment of the present invention includes a housing 30, a transmission shaft 10, a conductive member 20, multiple bearings and at least one conductive ring 60. The number of transmission shafts 10 is multiple, and the multiple transmission shafts 10 are supported on the housing 30 through multiple bearings. The first electrical contact end of the conductive member 20 is electrically connected to one of the transmission shafts 10, and the second electrical contact end of the conductive member 20 is suitable for electrically connecting to a grounding point on the vehicle body 100. At least one conductive ring 60 is sleeved on the transmission shaft 10 and connected between the transmission shaft 10 and the housing 30.

[0081] In this embodiment, it can be understood that the conductive member 20 can be connected to any transmission shaft 10, the number of conductive rings 60 can be one, two, three, or even more, each conductive ring 60 is connected between the transmission shaft 10 and the housing 30 to form a conductive path, multiple conductive rings 60 can be mounted on the same transmission shaft 10, or can be mounted on different transmission shafts 10 respectively, and the conductive ring 60 can be mounted on any one or more transmission shafts 10.

[0082] like Figure 6 As shown, taking the conductive member 20 electrically connected to the first transmission shaft 11 and the conductive ring 60 sleeved on the first transmission shaft 11 as an example, after the shaft current on the motor shaft 80 is transmitted to the first transmission shaft 11, a portion of the shaft current on the first transmission shaft 11 flows to the grounding point on the vehicle body 100 through the conductive member 20, and the other portion of the shaft current on the first transmission shaft 11 will flow according to the following path:

[0083] When the conductive member 20 is not provided with the second conductive layer 24, the flow path of this part of the shaft current on the first transmission shaft 11 is: conductive ring 60 → transmission case 30 → motor housing 110 → grounding wire 120 → vehicle body 100 grounding point. In this embodiment, since the motor is the source component for generating the shaft current, a grounding point connected to the vehicle body 100 or other parts of the vehicle is provided on the motor housing 110. It can also be understood that since power is directly transmitted between the motor and the transmission, the transmission case 30 and the motor housing 110 are fixedly connected together.

[0084] When the conductive member 20 is provided with a second conductive sub-layer 241, the flow path of this part of the shaft current on the first transmission shaft 11 is: conductive ring 60 → transmission case 30 → conductive member 20 → vehicle body 100 grounding point. In this embodiment, the conductive member 20 includes a first conductive core 22 and a second conductive sub-layer 241. Specifically, a part of the shaft current on the first transmission shaft 11 flows to the grounding point on the vehicle body 100 through the first conductive core 22, and a part of the shaft current on the first transmission shaft 11 flows through the conductive ring 60, the transmission case 30, and the second conductive sub-layer 241 in sequence and flows out to the grounding point of the vehicle body 100. It is understood that to prevent interference between these two conductive paths, the first conductive core 22 and the second conductive sublayer 241 need to be insulated from each other, so a second insulating sublayer 242 is required. Specifically, the second conductive sublayer 241 is wrapped around the outside of the first conductive core 22, and the second insulating sublayer 242 is wrapped around the outside of the second conductive sublayer 241. The conductive member 20 is inserted into the through hole 311 of the box body 30. The current on the box body 30 flows through the second conductive sublayer 241, which is in contact with the inner wall of the through hole 311, to the ground point of the vehicle body 100. The specific implementation is consistent with the above solution and will not be repeated here.

[0085] A transmission provided by an embodiment of the present invention includes a housing 30, a transmission shaft 10, a conductive member 20, multiple bearings, and at least one conductive ring 60. The multiple transmission shafts 10 are supported on the housing 30 through multiple bearings. The first electrical contact end of the conductive member 20 is electrically connected to one of the transmission shafts 10, and the second electrical contact end of the conductive member 20 is suitable for electrically connecting to a grounding point on the vehicle body 100. There is at least one insulating bearing among the multiple bearings, and at least one conductive ring 60 is sleeved on the transmission shaft 10 and connected between the transmission shaft 10 and the housing 30. In this embodiment, the insulated bearings protect themselves from electrical corrosion caused by shaft current. The conductive member 20 can directly direct a portion of the shaft current entering the transmission from the motor shaft 80 to a ground point on the vehicle body 100. At least one conductive ring 60 is disposed between the transmission shaft 10 and the case 30 to form a conductive path with lower resistivity, thereby avoiding or significantly reducing shaft current flow through the bearings. Furthermore, the current flowing into the transmission case is directed to the ground point on the vehicle body 100 via the grounding wire 120 or the conductive member 20, thereby preventing the accumulation of charge on the transmission case 30 and potentially damaging the transmission and other surrounding components. The triple shaft current routing combination of the insulated bearings, conductive member 20, and conductive ring 60 can significantly improve the efficiency of shaft current diversion from the transmission, maximally protecting the bearings within the transmission from electrical corrosion, and thus significantly extending bearing life, thereby improving the reliability and life of the transmission.

[0086] In the specific development of the transmission, one or two or three solutions among the insulating bearings, conductive parts 20 and conductive rings 60 can be selected based on the power supply voltage of the motor connected to the transmission, the type of motor, the magnitude of the shaft current detected on the motor shaft 80, and relevant cost factors of the transmission to achieve the best bearing electrical corrosion protection effect.

[0087] The electric powertrain provided according to an embodiment of the present invention can be a pure electric powertrain or a hybrid powertrain combining gasoline and electric power or gas and electric power. It includes a motor and the transmission of the above-described embodiment, the motor and the transmission being connected by a transmission shaft 10. Specifically, the motor includes a motor shaft 80, which is connected by a transmission shaft 10. A first electrical contact end of a conductive member 20 is electrically connected to the transmission shaft 10, and a second electrical contact end of the conductive member 20 is adapted to be electrically connected to a ground point on the vehicle body 100. By directly connecting the transmission shaft 10 to the ground point on the vehicle body 100 via the conductive member 20, the majority of the current conducted from the motor to the transmission shaft 10 is directly conducted through the conductive member 20, preventing electrical corrosion of the transmission bearings 90 caused by the shaft current, thereby improving the bearing life, the transmission life, and, consequently, the life of the electric powertrain. Simultaneously, the electric powertrain also achieves all the beneficial technical effects of the above-described transmission.

[0088] The vehicle according to the embodiment of the present invention, including the electric assembly according to the above embodiment, can improve the reliability and life of the vehicle.

[0089] Other structures and settings of the electric assembly according to the embodiment of the present invention, such as the speed change gear pair, are known to those skilled in the art and will not be described in detail here.

[0090] In this specification, reference to terms such as "specific embodiment" and "specific example" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0091] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A transmission suitable for use in a vehicle, characterized in that: The invention comprises a transmission shaft (10) and a conductive member (20), wherein the conductive member (20) has a first electrical contact end and a second electrical contact end, wherein the first electrical contact end is electrically connected to the transmission shaft (10), and the second electrical contact end is suitable for being electrically connected to a grounding point on a vehicle body (100).

2. The transmission according to claim 1, characterized in that There are multiple transmission shafts (10), and the multiple transmission shafts (10) are transmission-connected to each other, one of the transmission shafts (10) is suitable for transmission connection with the motor shaft (80), and the first electrical contact end of the conductive member (20) is electrically connected to at least one of the transmission shafts (10).

3. The transmission according to claim 1, characterized in that The conductive member (20) comprises a conductive brush (21), the conductive brush (21) being arranged at the first electrical contact end, and the conductive brush (21) being in contact with the surface of the transmission shaft (10).

4. The transmission according to claim 3, characterized in that The conductive brush (21) abuts against the end surface of the transmission shaft (10).

5. The transmission according to claim 3, characterized in that The conductive brush (21) is fixed to the first electrical contact end.

6. The transmission according to claim 1, characterized in that The conductive member (20) comprises a first conductive core (22) and a first insulating layer (23), the first electrical contact end is located on the first conductive core (22), and the first insulating layer (23) is coated on the outside of the first conductive core (22).

7. The transmission according to claim 6, characterized in that The conductive member (20) includes a conductive brush (21); a mounting hole (221) is provided on the end surface of the first conductive core (22); the conductive brush (21) is fixed in the mounting hole (221); and the conductive brush (21) abuts against the surface of the transmission shaft (10).

8. The transmission according to claim 1, wherein: The transmission further comprises a housing (30), the transmission shaft (10) is arranged on the inner side of the housing (30), the housing (30) is provided with a through hole (311) penetrating the inner side of the housing (30) and the outer side of the housing (30), the conductive member (20) is at least partially arranged in the through hole (311), the first electrical contact end is located on the inner side of the housing (30), and the second electrical contact end is located on the outer side of the housing (30).

9. The transmission according to claim 8, characterized in that A sealing member (50) is provided between the outer surface of the conductive member (20) and the inner wall of the through hole (311).

10. The transmission according to claim 8, characterized in that It also includes a conductive ring (60), which is sleeved on the speed-changing shaft, and the transmission shaft (10) is electrically connected to the box (30) through the conductive ring (60).

11. The transmission according to claim 10, characterized in that The conductive member (20) comprises a first conductive core (22), a first insulating layer (23) and a second conductive layer (24), wherein the first insulating layer (23) is coated on the outside of the first conductive core, the second conductive layer (24) is coated on the outside of the first insulating layer (23), and the second conductive layer (24) is in electrical contact with the inner wall of the through hole (311); The first electrical contact terminal is located on the first conductive core (22), and the second electrical contact terminal includes a first sub-terminal and a second sub-terminal, the first sub-terminal is located on the first conductive core (22), and the second sub-terminal is located on the second conductive layer (24).

12. The transmission according to claim 11, characterized in that The second conductive layer (24) comprises a second conductive sublayer (241) and a second insulating sublayer (242), and the second conductive sublayer (241) is coated on the outside of the first insulating layer (23); The second conductive sublayer (241) comprises a first section and a second section connected to each other, the first section is at least partially located in the through hole (311), and the second section is located outside the box (30); The second insulating sublayer (242) covers the second section.

13. The transmission according to claim 8, characterized in that It also includes a bracket (40), the bracket (40) is connected to the outside of the box (30), and the conductive member (20) outside the box (30) is fixed on the bracket (40).

14. The transmission according to claim 13, characterized in that A boss (31) is provided on the outside of the box body (30), and the through hole (311) passes through the end surface of the boss (31) and the inner wall surface of the box body (30).

15. The transmission according to claim 14, characterized in that A clamping platform (313) is provided on the boss (31), and the bracket (40) includes a buckle (42), and the bracket (40) is clamped on the clamping platform (313) via the buckle (42).

16. The transmission according to claims 1-15, characterized in that The transmission shaft (10) includes a first transmission shaft (11), the first transmission shaft (11) is suitable for being coaxially transmission-connected with the motor shaft (80), and the first electrical contact end of the conductive member (20) is electrically connected to the first transmission shaft (11).

17. The transmission according to any one of claims 1 to 15, characterized in that: The transmission further comprises: a box (30); a plurality of bearings, the transmission shaft (10) is connected to the housing (30) via the bearings, at least one of the plurality of bearings being an insulating bearing; and / or, At least one conductive ring (60) is sleeved on the transmission shaft (10) and connected to the case (30).

18. An electric assembly, characterized in that: It comprises a motor and the transmission according to claims 1 to 17, wherein the motor is in driving connection with the transmission shaft (10).

19. A vehicle, characterized in that: The invention comprises a vehicle body (100) and the electric assembly according to claim 18, wherein the second electrical contact end of the conductive member (20) is electrically connected to a ground point on the vehicle body (100).

Images