Electric drive assembly transmission structure and vehicle

Abstract

The application discloses an electric drive assembly transmission structure and a vehicle. The electric drive assembly transmission structure comprises an input shaft, an intermediate shaft and an output shaft which are sequentially connected in transmission. The input shaft is a shaft piece of an integral structure, and comprises a first shaft section, a second shaft section and a third shaft section which are sequentially reduced in diameter along an axial direction. The first shaft section is provided with a motor rotor. The second shaft section is provided with a first bearing, and a snap ring is arranged on a side of the first bearing away from the motor rotor. An inner ring of the first bearing and the input shaft are axially connected with the snap ring, respectively. The third shaft section is provided with a first gear which is used for meshing with a second gear on the intermediate shaft. The intermediate shaft is further provided with a third gear which is used for meshing with a fourth gear on the output shaft. Through the above structure, the transmission efficiency of the electric drive assembly can be effectively improved, and the problems of large axial displacement of the input shaft and abnormal sound of the shaft stage (NVH) can be avoided.

Description

Technical Field

[0001] This application relates to the field of vehicle manufacturing technology, and in particular to an electric drive assembly transmission structure and a vehicle equipped with the electric drive assembly transmission structure. Background Technology

[0002] With the booming development of the new energy vehicle industry, electric drive systems, as an essential component of new energy vehicles, are being used more and more widely. Currently, in order to improve the overall vehicle efficiency, higher requirements are being placed on the transmission efficiency of electric drive systems.

[0003] Generally, an electric drive system typically consists of five parts: the motor rotor (including the rotor shaft, i.e., the central shaft of the motor rotor) and bearings, the input shaft and bearings, the intermediate shaft and bearings, and the output shaft, which is connected to the differential and also has bearings. The conventional structural design of this electric drive system involves the input shaft, intermediate shaft, and output shaft being sequentially connected via gears, while the rotor shaft and input shaft are connected via splines. Because the splines on the input shaft and rotor shaft have a clearance fit at the connection point, the transmission efficiency is significantly reduced, resulting in low transmission efficiency. Furthermore, the large axial movement of the input shaft easily leads to NVH (Noise, Vibration, Harshness) problems such as shaft noise. NVH is a core indicator for measuring the comfort, quality, and premium feel of a vehicle's ride. Utility Model Content

[0004] In view of this, the purpose of this application is to provide an electric drive assembly transmission structure and vehicle that can effectively improve the transmission efficiency of the electric drive assembly and help avoid NVH problems such as large axial movement of the input shaft and abnormal shaft noise.

[0005] To achieve the above objectives, this application provides the following technical solution: An electric drive assembly transmission structure includes an input shaft, an intermediate shaft, and an output shaft connected in sequence. The input shaft is a one-piece shaft component, and along its axial direction, it includes a first shaft segment, a second shaft segment, and a third shaft segment with successively decreasing diameters. Specifically: the first shaft segment houses a motor rotor; the second shaft segment houses a first bearing, with a retaining ring on the side of the first bearing away from the motor rotor, the inner ring of the first bearing and the input shaft respectively engaging axially with the retaining ring; the third shaft segment houses a first gear, which meshes with a second gear on the intermediate shaft; the intermediate shaft also houses a third gear, which meshes with a fourth gear on the output shaft.

[0006] Optionally, in the above-mentioned electric drive assembly transmission structure, the surface of the second shaft segment is provided with an annular groove, wherein: the inner ring of the retaining ring is located inside the annular groove and is axially engaged with the input shaft; the outer ring of the retaining ring is located outside the annular groove and is axially engaged with the inner ring of the first bearing.

[0007] Optionally, in the above-described electric drive assembly transmission structure, the junction of the first shaft segment and the second shaft segment forms a first shaft shoulder, and the end of the inner ring of the first bearing away from the retaining ring is axially engaged with the first shaft shoulder.

[0008] Optionally, the above-described electric drive assembly transmission structure further includes a second bearing; the input shaft further includes a fourth shaft segment for mounting the second bearing, the fourth shaft segment being located at the end of the third shaft segment away from the second shaft segment, and the diameter of the fourth shaft segment being smaller than the diameter of the third shaft segment.

[0009] Optionally, the above-mentioned electric drive assembly transmission structure further includes a conductive ring for introducing shaft voltage into the motor housing; the conductive ring is sleeved on the first shaft section and located between the rotor core of the motor rotor and the first bearing.

[0010] Optionally, in the above-described electric drive assembly transmission structure, a third bearing is further provided on the input shaft. The third bearing is located on the side of the motor rotor away from the first gear, wherein: a wave-shaped gasket for abutting against the motor housing is provided on the side of the third bearing away from the motor rotor; and / or, the balls in the third bearing include ceramic balls.

[0011] Optionally, in the above-described electric drive assembly transmission structure, the input shaft further includes: a fifth shaft segment located outside the end of the first shaft segment away from the second shaft segment; a sixth shaft segment located outside the end of the fifth shaft segment away from the first shaft segment, used for mounting the third bearing; the junction of the sixth shaft segment and the fifth shaft segment forms a second shoulder, and the inner ring of the third bearing near the motor rotor is axially engaged with the second shoulder; the diameters of the first shaft segment, the fifth shaft segment, and the sixth shaft segment decrease sequentially.

[0012] Optionally, in the above-mentioned electric drive assembly transmission structure, the input shaft further includes: a seventh shaft segment located outside the end of the sixth shaft segment away from the fifth shaft segment; and an eighth shaft segment located outside the end of the seventh shaft segment away from the sixth shaft segment, used for mounting the rotary transformer rotor; the diameters of the sixth shaft segment, the seventh shaft segment, and the eighth shaft segment decrease sequentially.

[0013] Optionally, in the above-mentioned electric drive assembly transmission structure, the bearings on the input shaft, the intermediate shaft, and the output shaft are all deep groove ball bearings.

[0014] A vehicle is provided with the electric drive assembly transmission structure described above.

[0015] As can be seen from the above technical solution, in the electric drive assembly transmission structure and vehicle provided by this application, the integrated input shaft is both the input shaft and the rotor shaft in the electric drive assembly transmission structure. It not only serves as the input shaft in the electric drive assembly transmission structure to receive and transmit rotational power and torque, but also as the rotor shaft to directly transmit the high-speed rotation of the motor to the electric drive assembly transmission structure. This helps to reduce the axial movement between the input shaft and the motor rotor during motor operation. Compared with the separate structure and spline-connected input shaft and rotor shaft in the prior art, it can effectively reduce the loss of power and torque transmission efficiency caused by the spline clearance during the separate connection process, improve transmission efficiency, and effectively avoid problems such as shaft noise and reduced cleanliness and service life caused by wear at the connection position. In addition, it is also beneficial to reduce product weight. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0017] Figure 1 An exploded view of an electric drive assembly transmission structure provided in an embodiment of this application.

[0018] Figure 2 This is a schematic diagram of the combined structure of an electric drive assembly transmission structure provided in an embodiment of this application.

[0019] Figure 3 for Figure 2 The right view of the electric drive assembly transmission structure.

[0020] Figure 4 for Figure 2 Left view of the electric drive assembly transmission structure.

[0021] Figure 5 This is a schematic diagram of a retaining ring provided in an embodiment of this application.

[0022] Figure 6 This is a schematic diagram of the structure of a waveform gasket provided in an embodiment of this application.

[0023] Wherein: 1-Sixth bearing, 2-Fastener, 3-Output shaft, 4-Differential housing, 5-Seventh bearing, 6-Half shaft, 7-Eighth bearing, 8-Fourth bearing, 9-Intermediate shaft, 10-Fifth bearing, 11-Second bearing, 12-Snap ring, 13-First bearing, 14-Conductive ring, 15-Input shaft, 16-Motor rotor, 17-Third bearing, 18-Wave shim, 19-Resolver rotor, 151-First shaft segment, 152-Second shaft segment, 153-Third shaft segment, 154-Fourth shaft segment, 155-Fifth shaft segment, 156-Sixth shaft segment, 157-Seventh shaft segment, 158-Eighth shaft segment, 301-Fourth gear, 901-Second gear, 902-Third gear, 1501-First gear. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] Please see Figure 2 This application provides an electric drive assembly transmission structure, which includes an input shaft 15, an intermediate shaft 9, and an output shaft 3 connected in sequence. The input shaft 15 is a one-piece shaft component, and along its axial direction includes a first shaft segment 151, a second shaft segment 152, and a third shaft segment 153 with successively decreasing diameters. Wherein: The first shaft segment 151 is the central shaft of the motor rotor 16. In addition, the motor rotor 16 also includes a rotor core, a high-performance permanent magnet (usually embedded inside the core), end plates, locking rings, etc. The function of the motor rotor 16 is to be subjected to force and rotate in the rotating magnetic field generated by the motor stator, thereby converting electromagnetic energy into mechanical energy and outputting torque and speed. The second shaft section 152 is provided with a first bearing 13. The main function of the first bearing 13 is to support the input shaft 15 to rotate around its own axis. A retaining ring 12 is provided on the side of the first bearing 13 away from the motor rotor 16. The specific structure of the retaining ring 12 can be found in [reference needed]. Figure 1 and Figure 5 In this configuration, the inner ring of the first bearing 13 and the input shaft 15 are axially engaged with the retaining ring 12. The main function of the retaining ring 12 is to fix the first bearing 13 and prevent the first bearing 13 from axially moving during operation. The side of the first bearing 13 closest to the motor rotor 16 maintains a preset distance greater than zero from the rotor core. The surface of the third shaft segment 153 is provided with a first gear surface, forming a first gear 1501. That is, the first gear 1501 is provided on the third shaft segment 153 by machining. The first gear 1501 is used to mesh with the second gear 901 on the intermediate shaft 9. The intermediate shaft 9 is equipped not only with a second gear 901, but also with a third gear 902 that is coaxial with and adjacent to the second gear 901. The third gear 902 meshes with a fourth gear 301 on the output shaft 3. The main function of the intermediate shaft 9 is to transmit power from the input shaft 15 to the output shaft 3.

[0026] As can be seen, in the electric drive assembly transmission structure provided in this application embodiment, the integrated input shaft 15 is both the input shaft and the rotor shaft in the electric drive assembly transmission structure. It not only serves as the input shaft in the electric drive assembly transmission structure to receive and transmit rotational power and torque, but also as the rotor shaft to directly transmit the high-speed rotation of the motor to the electric drive assembly transmission structure. This helps to reduce the axial movement between the input shaft 15 and the motor rotor during motor operation. Compared with the separate structure and spline-connected input shaft and rotor shaft in the prior art, it can effectively reduce the loss of power and torque transmission efficiency caused by the spline gap during the separate connection process, improve transmission efficiency, and effectively avoid problems such as shaft noise and reduced cleanliness and service life caused by wear at the connection position. In addition, it is also beneficial to reduce product weight.

[0027] Please see Figure 1 and Figure 2 In specific implementation, the diameter of the third gear 902 can be smaller than the diameter of the second gear 901, the diameter of the first gear 1501 can be smaller than the diameter of the second gear 901, and the diameter of the third gear 902 can be smaller than the diameter of the fourth gear 301. Furthermore, in the gear set formed by the meshing of the third gear 902 and the fourth gear 301, the third gear 902 is the driving gear, and the fourth gear 301 is the driven gear; in the gear set formed by the meshing of the first gear 1501 and the second gear 901, the first gear 1501 is the driving gear, and the second gear 901 is the driven gear. This allows power to be transmitted sequentially along the input shaft 15, intermediate shaft 9, and output shaft 3, while simultaneously reducing the rotational speed and increasing the torque.

[0028] In practical implementation, the second gear 901 can be machined onto the intermediate shaft 9, making the intermediate shaft 9 and the second gear 901 a single integrated structure. Alternatively, a gear ring structure can be used, with the second gear 901 mounted on the intermediate shaft 9 via fasteners and / or interference fits, forming an assembly. Similarly, the third gear 902 can be machined onto the intermediate shaft 9, making the intermediate shaft 9 and the third gear 902 a single integrated structure. Alternatively, a gear ring structure can be used, with the third gear 902 mounted on the intermediate shaft 9 via fasteners and / or interference fits, forming an assembly. Furthermore, the output shaft 3 is generally the power input end of the differential sub-assembly, located on the side of the differential housing 4 away from the half-shaft 6. The fourth gear 301 is fitted onto the output shaft 3 and fixedly connected to the differential housing 4 via fasteners 2. See details... Figure 1 and Figure 2 .

[0029] In some embodiments, the surface of the second shaft segment 152 is provided with an annular groove 1521, wherein the inner ring of the retaining ring 12 is located within the annular groove 1521 and is axially engaged with the input shaft 15; and the outer ring of the retaining ring 12 is located outside the annular groove 1521 and is axially engaged with the inner ring of the first bearing 13. Furthermore, the junction of the second shaft segment 152 and the first shaft segment 151 forms a first shoulder, and the end of the inner ring of the first bearing 13 away from the retaining ring 12 is axially engaged with the first shoulder. Thus, the first bearing 13 is axially fixed on the input shaft 15 through the first shoulder and the retaining ring 12.

[0030] In some embodiments, the input shaft 15 is further provided with a fourth shaft segment 154 for mounting the second bearing 11. The fourth shaft segment 154 is located at the end of the third shaft segment 153 away from the second shaft segment 152, and the diameter of the fourth shaft segment 154 is smaller than the diameter of the third shaft segment 153. The main function of the second bearing 11 is to support the input shaft 15 to rotate around its own axis. Specifically, the inner ring of the second bearing 11 is fitted onto the fourth shaft segment 154 with an interference fit, and the shoulder at the junction of the fourth shaft segment 154 and the third shaft segment 153 can axially limit the inner ring of the second bearing 11.

[0031] In some embodiments, the electric drive assembly transmission structure described above also includes a conductive ring 14. This conductive ring 14 is sleeved on the first shaft segment 151 of the input shaft 15, located between the rotor core of the motor rotor 16 and the first bearing 13. The conductive ring 14 allows the shaft voltage to be transmitted to the motor housing. The specific installation position of the conductive ring 14 on the first shaft segment 151 can be found in [reference needed]. Figure 1The annular mounting area 1511 is included. Specifically, the axial distance between the conductive ring 14 and the rotor core is greater than zero, and the axial distance between the conductive ring 14 and the first bearing 13 is also greater than zero. During operation, the conductive ring 14 provides a low-resistance electrical path for the rotating bearing, preventing current from flowing through the bearing's interior and thus avoiding electro-corrosion damage to the bearing, protecting the bearing on the input shaft 15. It should be noted that the conductive ring 14 is suitable for 800V platform electric drive assemblies, and can conduct shaft voltage to the motor housing, preventing shaft voltage from damaging the bearing oil film and causing bearing failure. This part is optional and can be omitted in 400V platform electric drive assemblies.

[0032] In some embodiments, a fifth shaft segment 155 and a sixth shaft segment 156 are provided at the end of the input shaft 15 away from the first gear 1501. Specifically: the fifth shaft segment 155 is located outside the end of the first shaft segment 151 away from the second shaft segment 152; the sixth shaft segment 156 is located outside the end of the fifth shaft segment 155 away from the first shaft segment 151, and a third bearing 17 is mounted thereon. The diameters of the first shaft segment 151, the fifth shaft segment 155, and the sixth shaft segment 156 decrease sequentially, so that the second shoulder formed at the junction of the fifth shaft segment 155 and the sixth shaft segment 156 can axially limit the left side of the inner ring of the third bearing 17. The third bearing 17 is a front ball bearing for the drive motor, installed at the front end of the motor rotor 16, and its main function is to support the rotation of the input shaft 15. In some embodiments, when the voltage platform of the electric drive assembly transmission structure provided in this application is 800V, the balls inside the third bearing 17 are ceramic balls, which have better resistance to electrolytic corrosion compared to traditional steel ball bearings. Furthermore, when the balls in the third bearing 17 are ceramic balls, they are compatible with both 400V and 800V voltage platforms. It should be noted that when the induced shaft current generated by magnetic field asymmetry passes through the bearing, it can cause electro-corrosion (forming washboard-like ablation marks on the raceway), leading to abnormal bearing noise and premature failure. Ceramic balls, due to their excellent insulation properties, can completely block the shaft current path, thus avoiding electro-corrosion problems. At the same time, because ceramic balls are lighter than steel balls, they can meet the ultra-high speed requirements of motors. During high-speed rotation, the centrifugal force and gyroscopic torque generated are significantly reduced, thereby greatly reducing frictional heat generation and cage pressure. This allows the bearing's limiting speed (DN value) to be 30%-60% higher than that of steel ball bearings.

[0033] Please see Figure 1 and Figure 2In specific implementation, the junction of the fifth shaft segment 155 and the sixth shaft segment 156 forms a second shoulder, and the inner ring of the third bearing 17, near the motor rotor 16, is axially engaged with the second shoulder. Furthermore, a wave-shaped shim 18 is provided on the side of the third bearing 17 away from the motor rotor 16. One side of the wave-shaped shim 18 mates with the third bearing 17, and the other side abuts against the motor housing, effectively mitigating the axial movement of the input shaft during motor operation. The third bearing 17 is a ball bearing, which, combined with the wave-shaped shim 18, effectively reduces the impact vibration caused by the axial movement of the input shaft during motor operation. When this transmission structure is applied to an 800V platform electric drive assembly, the third bearing 17 is a deep groove ball bearing with internal ceramic balls. When used in a 400V platform electric drive assembly, the third bearing 17 can be a deep groove ball bearing with ordinary steel balls or a deep groove ball bearing with internal ceramic balls.

[0034] Specifically, please see Figure 6 The wave-shaped shim 18 is a thin metal washer made of spring steel, installed between the outer ring of the third bearing 17 and the inner wall of the motor housing. It applies an axial force to the inner and outer rings of the bearing, causing the rolling elements and raceways inside to make tight contact and eliminating backlash. At the same time, the elasticity of the wave-shaped shim 18 can effectively eliminate the axial clearance of the input shaft 15, improving the control accuracy and responsiveness of the motor. The wave-shaped shim 18 is a miniature elastomer that can absorb and attenuate high-frequency vibrations from the bearing and vibration waves transmitted to the housing, which has a significant positive effect on reducing the NVH performance of the electric drive system, especially shaft-level noise.

[0035] In practical implementation, by applying conductive rings 14 and a third bearing 17 with internal ceramic balls, the shaft voltage transmitted from common-mode voltage and phase voltage can be reduced, preventing electrolytic corrosion damage to the bearing raceway when the shaft voltage exceeds the maximum withstand pressure of the bearing oil film. This design is compatible with both 800V and 400V electric drive assemblies. It should be noted that the common-mode voltage inside the motor forms coupling paths through various parasitic capacitances, ultimately creating a voltage difference between the shaft and the housing—the shaft voltage. When this voltage accumulates sufficiently and breaks down the lubricating grease film, it generates shaft current, causing devastating damage to the bearing—electrolytic corrosion. The DC bus voltage of the 800V system is higher, and the amplitude of its common-mode voltage is significantly higher than that of the 400V system. Traditional transmission structures cannot effectively reduce or eliminate this shaft voltage. This application employs a ceramic ball bearing for the third bearing 17 located at the front end of the input shaft 15 (which is also the motor rotor shaft). Due to its excellent insulation properties, the ceramic ball bearing completely blocks the path of shaft current, thus preventing electro-corrosion. A conductive ring 14 is arranged at the rear end of the motor shaft, providing a low-impedance discharge path for the shaft voltage. This "diverts" harmful shaft current and safely discharges it to the housing (ground), preventing the voltage across the bearing from rising to the threshold that breaks down the oil film. Ultimately, this protects the bearing and prevents electro-corrosion, fundamentally preventing it. Therefore, the electric drive assembly transmission structure provided by this application is flexibly compatible with multiple voltage platforms such as 400V and 800V.

[0036] Furthermore, in some embodiments, a seventh shaft segment 157 and an eighth shaft segment 158 ​​are also provided at the end of the input shaft 15 away from the first gear 1501. For example... Figure 1 As shown, the first shaft segment 151, the fifth shaft segment 155, the sixth shaft segment 156, the seventh shaft segment 157, and the eighth shaft segment 158 ​​are connected sequentially along the axial direction, with their diameters decreasing sequentially. Specifically, the seventh shaft segment 157 is located outside the end of the sixth shaft segment 156 furthest from the fifth shaft segment 155; the eighth shaft segment 158 ​​is located outside the end of the seventh shaft segment 157 furthest from the sixth shaft segment 156, and is used to mount the rotary transformer rotor 19. The rotary transformer rotor 19 is used in conjunction with the rotary transformer stator to detect the motor position.

[0037] Traditional electric drive assembly transmission structures typically employ a bearing configuration of "2 ball bearings + 4 tapered bearings or 4 ball bearings + 2 tapered bearings." Specifically, the front and rear bearings on the intermediate shaft 9 use tapered bearings, the front and rear bearings of the differential subassembly use tapered bearings, and ball bearings are used in other positions. In tapered bearings, the rolling elements and raceways have line contact, resulting in a large contact area and thus greater frictional torque. Furthermore, sliding friction between the rolling element ends and the flanges generates additional frictional losses. Especially at high speeds, churning losses and wind resistance losses are also greater, leading to lower system transmission efficiency. Therefore, in the new electric drive assembly transmission structure provided in this application, the bearings on the input shaft 15, intermediate shaft 9, and output shaft 3 are all deep groove ball bearings. Compared to tapered bearings and the traditional combination of ball and tapered bearings, this significantly improves transmission efficiency. It should be noted that the rolling elements and raceways in ball bearings primarily have point contact, resulting in lower starting and running frictional torques, especially under high-speed and light-load conditions, where their frictional loss advantage is very significant. Tests have shown that the bearing solution proposed in this application can improve the system efficiency by approximately 0.5%-2.5% compared to the bearing solution of the traditional transmission structure.

[0038] In practice, the strength, hardness, wear resistance, and fatigue resistance of bearings can be significantly improved by using higher-performance materials, thereby increasing the bearing's load capacity and service life. For example, using high-strength carburized steel or high-temperature steel to make the inner and outer rings of the bearing, and combining them with ceramic balls made of silicon nitride (Si3N4) material, forms a "hybrid ceramic bearing," which can significantly improve load capacity, lifespan, and reliability. Furthermore, using carburized steel (such as 18CrNiMo7-6) to manufacture bearings and employing carburizing and quenching processes can improve the bearing's fatigue resistance and heavy-load capacity; using GCr15 hardened steel or 440C stainless steel can improve the bearing's hardness and wear resistance; using hybrid ceramic bearings, where the ceramic balls are made of Si3N4 and the steel rings used to manufacture the inner and outer rings are made of GCr15 or M50, can improve the bearing's high-speed, heavy-load performance; using M50 high-temperature steel to manufacture the inner and outer rings, with ceramic balls inside, can improve the bearing's high-temperature and high-load resistance; using 440C stainless steel or super stainless steel to manufacture the inner and outer rings, with ceramic balls inside, can improve the bearing's high-load capacity in corrosive environments; and using carburized steel to manufacture the steel rings and balls, along with a copper alloy cage, can improve the bearing's resistance to impact loads.

[0039] Specifically, please see Figure 1 and Figure 2 ,as well as Figure 3 and Figure 4The first bearing 13, the second bearing 11, and the third bearing 17 on the input shaft 15 are all deep groove ball bearings. Furthermore, a fourth bearing 8 and a fifth bearing 10 are respectively installed at both ends of the intermediate shaft 9. Both bearings 8 and 10 are deep groove ball bearings, assembled onto the intermediate shaft 9 by interference fit. Specifically, bearing 8 is the rear bearing of the intermediate shaft, its main function being to support the rotation of the intermediate shaft, hence the use of a deep groove ball bearing; bearing 10 is the front bearing of the intermediate shaft, its main function being to support the rotation of the intermediate shaft, hence the use of a deep groove ball bearing. Additionally, on the output shaft 3, a sixth bearing 1 and a seventh bearing 5 are respectively installed at both ends of the differential housing 4 of the differential assembly. Both bearings 1 and 5 are deep groove ball bearings. Moreover, the differential housing 4 is connected to the half-shaft 6, and an eighth bearing 7, also a deep groove ball bearing, is installed at the end of the half-shaft 6 furthest from the differential housing 4. Among them, the sixth bearing 1 is the rear bearing of the differential, which can be a deep groove ball bearing. Its main function is to support the rotation of the differential sub-assembly, reduce the friction coefficient during its movement, and ensure its rotational accuracy. The seventh bearing 5 is the front bearing of the differential, which can also be a deep groove ball bearing. Its main function is to support the rotation of the differential sub-assembly, reduce the friction coefficient during its movement, and ensure its rotational accuracy. The eighth bearing 7 is a short half-shaft ball bearing. Its main function is to support the rotation of the half-shaft 6. Its inner ring and half-shaft 6 are fastened together by interference fit, and its outer ring is clearance fit with the equipment housing. Half-shaft 6 and the eighth bearing 7 are used together. Both are optional parts and can be selected according to the overall vehicle structure and layout requirements.

[0040] It should be noted that half-shaft 6 is a short half-shaft, used to connect the differential sub-assembly and the wheels. Its main function is to continue the transmission to the wheels via half-shaft 6 after power has been transmitted sequentially through input shaft 15, intermediate shaft 9, and output shaft 3. For details, please refer to [link to relevant documentation]. Figure 1 and Figure 2 One end of the half-shaft 6 is splined with the center of the differential housing 4, and the other end is splined with the wheel hub.

[0041] Furthermore, it should be noted that the output shaft 3 includes a differential sub-assembly (including the differential housing 4), a fourth gear 301, and a half-shaft 6. The differential sub-assembly is a functional module assembled from key components such as the differential housing 4, planetary gears, and half-shaft gears. It connects with the external half-shaft of the vehicle to transmit power from the electric drive system to the wheels. Its main function is to allow the two wheels to rotate at different speeds while transmitting power to the two drive wheels. The fourth gear 301 is a ring gear structure, installed on the differential housing 4 of the differential sub-assembly, and cooperates with the third gear 902 (drive wheel) on the intermediate shaft 9. Its function is to transmit power from the intermediate shaft 9 to the differential housing 4, thereby amplifying torque and reducing speed, while providing the structural and rotational foundation for the entire differential sub-assembly.

[0042] This application also provides a vehicle in which the electric drive assembly transmission structure described above is provided.

[0043] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed.

[0044] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0045] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A transmission structure for an electric drive assembly, characterized in that, It includes an input shaft, an intermediate shaft, and an output shaft connected in sequence for transmission; the input shaft is a one-piece shaft component, and the input shaft includes a first shaft segment, a second shaft segment, and a third shaft segment with successively decreasing diameters along the axial direction; wherein: The first shaft segment is equipped with a motor rotor; The second shaft segment is provided with a first bearing, and a retaining ring is provided on the side of the first bearing away from the motor rotor. The inner ring of the first bearing and the input shaft are respectively axially engaged with the retaining ring. The third shaft segment is provided with a first gear, which is used to mesh with a second gear on the intermediate shaft; A third gear is also provided on the intermediate shaft, which is used to mesh with a fourth gear on the output shaft.

2. The electric drive assembly transmission structure according to claim 1, characterized in that, The surface of the second shaft segment is provided with an annular groove, wherein: The inner ring of the retaining ring is located within the annular groove and is axially engaged with the input shaft; The outer ring of the retaining ring is located outside the annular groove and is axially engaged with the inner ring of the first bearing.

3. The electric drive assembly transmission structure according to claim 2, characterized in that, The first shaft segment and the second shaft segment meet to form a first shaft shoulder, and the inner ring of the first bearing is axially engaged with the first shaft shoulder at the end away from the retaining ring.

4. The electric drive assembly transmission structure according to claim 1, characterized in that, It also includes a second bearing; The input shaft further includes a fourth shaft segment for mounting the second bearing, the fourth shaft segment being located at the end of the third shaft segment away from the second shaft segment, and the diameter of the fourth shaft segment being smaller than the diameter of the third shaft segment.

5. The electric drive assembly transmission structure according to claim 1, characterized in that, It also includes a conductive ring for introducing shaft voltage into the motor housing; The conductive ring is sleeved on the first shaft segment and located between the rotor core of the motor rotor and the first bearing.

6. The electric drive assembly transmission structure according to claim 1, characterized in that, A third bearing is also provided on the input shaft, and the third bearing is located on the side of the motor rotor away from the first gear, wherein: The third bearing is provided with a wave-shaped gasket on the side away from the motor rotor for abutting against the motor housing; And / or, the balls in the third bearing include ceramic balls.

7. The electric drive assembly transmission structure according to claim 6, characterized in that, The input axis also includes: The fifth shaft segment is located outside the end of the first shaft segment that is furthest from the second shaft segment; The sixth shaft segment, located at the end of the fifth shaft segment away from the first shaft segment, is used to install the third bearing; the junction of the sixth shaft segment and the fifth shaft segment forms a second shoulder, and the inner ring of the third bearing, near the end of the motor rotor, is axially engaged with the second shoulder; The diameters of the first shaft segment, the fifth shaft segment, and the sixth shaft segment decrease sequentially.

8. The electric drive assembly transmission structure according to claim 7, characterized in that, The input axis also includes: The seventh shaft segment is located outside the end of the sixth shaft segment that is furthest from the fifth shaft segment; The eighth shaft segment, located at the end of the seventh shaft segment away from the sixth shaft segment, is used to mount the rotary transformer rotor; The diameters of the sixth, seventh, and eighth shaft segments decrease sequentially.

9. The electric drive assembly transmission structure according to any one of claims 1 to 8, characterized in that, The bearings on the input shaft, the intermediate shaft, and the output shaft are all deep groove ball bearings.

10. A vehicle, characterized in that, It is provided with an electric drive assembly transmission structure as described in any one of claims 1 to 9.

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