Powertrain comprising two-stage planetary coaxial reducer and electric vehicle

Abstract

The present application provides a powertrain comprising a two-stage planetary coaxial reducer and an electric vehicle. The interior of a motor housing of the powertrain is used for accommodating a motor stator of a driving motor in the powertrain. A central hole of the motor stator is used for accommodating a motor rotor of the driving motor. The interior of a reducer housing is used for accommodating a first-stage planetary gear set and a second-stage planetary gear set of the planetary coaxial reducer. The first-stage planetary gear set is configured to be transmittingly connected to the second-stage planetary gear set and a motor shaft of the driving motor. The motor housing is used for fixing the reducer housing of the powertrain. The reducer housing is used for enclosing an opening of the motor housing and is used for fixing a bearing of the motor shaft. The motor rotor and a gear set of the first-stage planetary gear set are arranged in the motor housing on two sides of the bearing of the motor shaft in the axial direction of the driving motor, so that the planetary coaxial reducer and the driving motor are compactly arranged, and thus the axial dimension of the powertrain can be reduced, thereby miniaturizing the powertrain, thus optimizing the layout of the powertrain in the whole vehicle.

Description

Powertrains and electric vehicles with two-stage planetary coaxial reducers

[0001] This application claims priority to Chinese Patent Application No. 202510129600.6, filed on January 27, 2025, entitled "Powertrain with Two-Stage Planetary Coaxial Reducer and Electric Vehicle", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of electric vehicle technology, and in particular to a powertrain with a two-stage planetary coaxial reducer and an electric vehicle. Background Technology

[0003] As the market demands increasingly lighter, smaller, and more reliable powertrains for new energy vehicles, planetary coaxial reducers, with their coaxial input and output shafts, have gained widespread attention due to their compact structure, smaller footprint, and ability to achieve strong torque transmission within a limited space. Currently, most planetary coaxial reducers employ a single-and-a-half-stage reduction architecture, resulting in a low speed ratio that cannot meet the deceleration requirements of electric vehicles. Therefore, two-stage planetary coaxial reducers are needed to improve deceleration capability. However, two-stage planetary coaxial reducers have a larger axial dimension, leading to less compact assembly with the drive motor in the powertrain and making the overall powertrain assembly difficult within the vehicle. Summary of the Invention

[0004] This application provides a powertrain and electric vehicle with a two-stage planetary coaxial reducer to reduce the axial dimension of the powertrain.

[0005] In a first aspect, this application provides a powertrain with a two-stage planetary coaxial reducer. The powertrain is used to drive an electric vehicle. The powertrain housing includes a motor housing and a reducer housing. The motor housing houses the stator of the drive motor, and the central hole of the stator houses the rotor of the drive motor. The reducer housing houses the first-stage and second-stage planetary gear sets of the planetary coaxial reducer. The first-stage planetary gear set is used to drive the second-stage planetary gear set and the motor shaft of the drive motor. The second-stage planetary gear set is used to drive the wheels of the electric vehicle. The motor housing secures the reducer housing of the powertrain, and the reducer housing encloses the opening of the motor housing and the bearings for fixing the motor shaft. The gear sets of the motor rotor and the first-stage planetary gear set are arranged inside the motor housing on both sides of the bearings along the axial direction of the drive motor.

[0006] In this embodiment, because the planetary coaxial reducer uses a first-stage planetary gear set and a second-stage planetary gear set to achieve two-stage reduction, the axial length of the planetary coaxial reducer is relatively long. This makes it easy to have a large axial dimension of the powertrain when the planetary coaxial reducer and the drive motor are arranged along the axial direction of the drive motor, which is not conducive to the miniaturization of the powertrain. By arranging the motor rotor and the gear set of the first-stage planetary gear set inside the motor housing on both sides of the bearing of the motor shaft along the axial direction of the drive motor, and arranging the gear set of the first-stage planetary gear set inside the motor housing, the arrangement of the planetary coaxial reducer makes full use of the space inside the motor housing. It also allows the planetary coaxial reducer and the drive motor to be arranged compactly, so that the arrangement of the first-stage planetary gear set of the planetary coaxial reducer does not occupy additional space outside the space of the motor housing along the axial direction of the drive motor. This shortens the axial dimension of the powertrain, miniaturizes the powertrain, and optimizes the layout of the powertrain in the vehicle.

[0007] In one embodiment, the motor housing surrounds the end winding of the motor stator on the side facing the planetary coaxial reducer, and the end winding of the motor stator on the side facing the planetary coaxial reducer surrounds the bearing of the motor shaft circumferentially around the powertrain.

[0008] In this embodiment, the motor housing surrounds the end winding of the motor stator on the side facing the planetary coaxial reducer, such that the end winding of the motor stator on the side facing the planetary coaxial reducer is arranged within the motor housing along the axial direction of the powertrain, without occupying additional space in the motor housing outside the axial direction of the powertrain. The end winding of the motor stator on the side facing the planetary coaxial reducer surrounds the bearing of the motor shaft circumferentially around the powertrain, such that the bearing of the motor shaft can be arranged radially and axially within the end winding on the side facing the planetary coaxial reducer. This allows the arrangement of the bearings on the motor shaft to fully utilize the space inside the end winding, making the arrangement of the bearings and the motor rotor more compact, thereby shortening the axial dimension of the powertrain.

[0009] In one embodiment, the outer diameter of the gear ring of the first-stage planetary gear set is less than or equal to the inner diameter of the center hole of the motor stator, and the outer diameter of the gear ring of the second-stage planetary gear set is greater than the inner diameter of the center hole of the motor stator and less than or equal to the outer diameter of the motor stator.

[0010] In this embodiment, the outer diameter of the gear ring of the first-stage planetary gear set is less than or equal to the inner diameter of the central hole of the motor stator. The smaller outer diameter of the gear ring allows the first-stage planetary gear set to be arranged inside the motor housing, and also makes it easier to extend part of the reducer housing that houses the first-stage planetary gear set into the motor housing, which helps to reduce the axial dimension of the powertrain. The larger inner diameter of the central hole of the motor stator allows for the accommodation of part of the reducer housing that extends into the motor housing, making the planetary coaxial reducer and motor stator structure more compact, which also helps to shorten the axial dimension of the powertrain.

[0011] In this embodiment, because the primary planetary gear set needs to be embedded within the motor housing, the outer diameter of the gear ring of the primary planetary gear set is relatively small, resulting in insufficient deceleration of the planetary coaxial reducer. To ensure the normal operation of the electric vehicle, a larger secondary planetary gear set is required for deceleration. The outer diameter of the gear ring of the secondary planetary gear set is larger than the inner diameter of the center hole of the motor stator and smaller than or equal to the outer diameter of the motor stator, giving the secondary planetary gear set a larger outer diameter, which can further reduce the power transmitted by the primary planetary gear set. However, the large outer diameter of the gear ring of the secondary planetary gear set cannot be accommodated within the motor housing, thus requiring the secondary planetary gear set to be positioned on the outside of the motor housing.

[0012] In one embodiment, the gear ring of the first-stage planetary gear set is less than or equal to the outer diameter of the outer circumferential surface around which the end windings surround, and the outer diameter of the gear ring of the second-stage planetary gear set is greater than the outer diameter of the outer circumferential surface around which the end windings surround, but less than or equal to the outer diameter of the motor stator.

[0013] In this embodiment, the gear ring of the first-stage planetary gear set is smaller than or equal to the outer diameter of the outer circumferential surface around the end winding, thereby making the first-stage planetary gear set smaller. This allows the first-stage planetary gear set to be arranged inside the motor housing, and also allows a portion of the reducer housing used to house the first-stage planetary gear set to extend into the inner side of the end winding. This allows for the reuse of some axial space within the end winding, making the arrangement of the first-stage planetary gear set and the drive motor more compact, thereby shortening the axial space of the powertrain.

[0014] In this embodiment, the outer diameter of the gear ring of the second-stage planetary gear set is larger than the outer diameter of the outer circumferential surface around the end winding, and smaller than or equal to the outer diameter of the motor stator. On the one hand, the larger outer diameter of the gear ring of the second-stage planetary gear set allows for further deceleration of the power transmitted by the first-stage planetary gear set, thereby meeting the deceleration requirements of the entire vehicle. On the other hand, the larger outer diameter of the gear ring of the second-stage planetary gear set prevents it from being installed inside the end winding within the motor housing, thus requiring the second-stage planetary gear set to be positioned on the outside of the motor housing.

[0015] In one embodiment, the side of the reducer housing facing the drive motor is also used to fix the outer ring of a resolver sensor, and the inner ring of a resolver sensor is arranged along the axial direction of the drive motor between the bearing of the motor shaft and the motor rotor. The motor shaft is used to extend through the inner ring of a resolver sensor into the interior of the reducer housing to drive a primary planetary gear set.

[0016] In this embodiment, the side of the reducer housing facing the drive motor is also used to fix the outer ring of a resolver sensor. The inner ring of the resolver sensor is arranged along the axial direction of the drive motor between the bearing of the motor shaft and the motor rotor. This allows the arrangement of the resolver sensor to make full use of the axial space between the bearing of the motor shaft and the motor rotor, and also allows the resolver sensor to be accommodated in the end winding. This further utilizes the space in the end winding, making the layout of the components in the powertrain more compact. This helps to reduce the axial dimension of the powertrain, thereby obtaining a smaller powertrain and optimizing the layout of the powertrain in the vehicle.

[0017] In this embodiment, the motor shaft is used to pass through the inner ring of the resolver sensor and extend into the interior of the reducer housing to drive the first-stage planetary gear set. This facilitates the resolver sensor to receive the rotational speed information of the motor rotor driven by the motor shaft. Furthermore, the extension of the motor shaft into the interior of the reducer housing helps to improve the transmission stability between the motor shaft and the first-stage planetary gear set.

[0018] In one embodiment, the reducer housing includes a motor shaft bearing groove on the side facing the drive motor. The motor shaft bearing groove is used to fix the outer ring of the motor shaft bearing, and the inner ring of the motor shaft bearing is fitted onto the motor shaft. The groove wall of the motor shaft bearing groove is used to fix a sensor bracket, which is used to fix the outer ring of a resolver sensor and to surround the resolver sensor circumferentially. The bottom of the motor shaft bearing groove includes a through hole through which the motor shaft extends into the interior of the reducer housing.

[0019] In this embodiment, the groove wall of the motor shaft bearing groove is used to fix a sensor bracket. The sensor bracket is used to fix the outer ring of a resolver sensor and to surround the resolver sensor circumferentially. This arrangement of the sensor bracket utilizes the space outside the resolver sensor inside the radial end winding of the powertrain, without occupying too much axial space of the powertrain, which is beneficial to making the axial dimension of the powertrain smaller.

[0020] In this embodiment, the sensor bracket is fixed to the groove wall of the motor shaft bearing groove, which is used to fix the bearing of the motor shaft. Thus, the sensor bracket can be reused as a baffle for the bearing of the motor shaft, limiting the bearing of the motor shaft within the bearing groove, thereby reducing the axial movement of the bearing of the motor shaft.

[0021] In this embodiment, the bottom of the motor shaft bearing groove includes a through hole, allowing the motor shaft to pass through the bottom of the motor shaft bearing groove from a position close to the rotor and extend into the interior of the reducer housing to drive the primary planetary gear set.

[0022] In one embodiment, one end of the motor shaft extending into the interior of the reducer housing is used as the sun gear of the first-stage planetary gear set to drive the planet gears of the first-stage planetary gear set.

[0023] In this embodiment, the end of the motor shaft that extends into the reducer housing is used as the sun gear of the first-stage planetary gear set, which makes the transmission between the motor shaft and the first-stage planetary gear set more direct. No additional transmission components are needed, which helps to make the transmission between the drive motor and the planetary coaxial reducer more stable. It also makes the arrangement between the motor shaft and the first-stage planetary gear set more compact, and the axial dimension of the powertrain is shorter, which is conducive to the miniaturization of the powertrain.

[0024] In one embodiment, the motor shaft is an integral shaft, which makes the powertrain more integrated and also helps to improve the stability and reliability of the powertrain.

[0025] In one embodiment, the reducer housing includes a first housing and a second housing. The first housing encloses the opening of the motor housing, and the second housing encloses the first housing. The first housing is recessed along the direction towards the drive motor, forming a first groove on the side of the first housing opposite to the drive motor. The inner wall of the first groove is used to fix the gear ring of the first-stage planetary gear set.

[0026] In this embodiment, the first housing is recessed along the direction toward the drive motor to form a first groove on the side of the first housing away from the drive motor. The inner wall of the first groove is used to fix the gear ring of the first-stage planetary gear set, so that the first-stage planetary gear set is also fixed in the first groove. This allows the first-stage planetary gear set to be arranged inside the motor housing, thereby making full use of the axial space inside the motor housing. This ensures that the arrangement of the first-stage planetary gear set of the planetary coaxial reducer does not occupy too much axial space outside the motor housing, which is beneficial for the powertrain to have a smaller axial dimension.

[0027] In this embodiment, the first housing is recessed in the direction toward the drive motor to form a first groove on the side of the first housing away from the drive motor. The first housing is used to enclose the opening of the motor housing, so that the first housing can be recessed from the opening of the motor housing toward the drive motor. This arrangement of the first housing can reuse the space inside the motor housing, which is beneficial to make the powertrain have a smaller axial dimension when the reducer and the drive motor are arranged along the axial direction of the powertrain.

[0028] In one embodiment, the first groove further accommodates a thrust needle roller bearing and an oil collecting baffle. The thrust needle roller bearing rotatably connects the planet carrier of the first-stage planetary gear set and the first housing. Along the axial direction of the powertrain, the thrust needle roller bearings are arranged between the planetary shaft of the first-stage planetary gear set and the bottom of the first groove. The opening of the axial bore of the planetary shaft in the first-stage planetary gear set is exposed through the thrust needle roller bearing. The thrust needle roller bearing surrounds the outer periphery of the motor shaft oil hole. The clearance in the thrust needle roller bearing is used to transmit oil output from the motor shaft oil hole to the opening of the planetary shaft of the first-stage planetary gear set. The oil collecting baffle surrounds the outer periphery of the thrust needle roller bearing, covering the outer peripheral surface of the thrust needle roller bearing and the opening of the axial bore of the planetary shaft in the first-stage planetary gear set, and connecting the clearance of the outer peripheral surface of the thrust needle roller bearing and the opening of the axial bore of the planetary shaft in the first-stage planetary gear set.

[0029] In this embodiment, the clearance in the thrust needle roller bearing is used to transmit oil from the motor shaft oil hole to the axial bore opening of the planetary shaft of the first-stage planetary gear set. This allows the oil collecting baffle to guide the oil thrown out of the motor shaft oil hole into the axial bore opening of the planetary shaft of the first-stage planetary gear set, thereby lubricating the planetary gears of the first-stage planetary gear set. The oil collecting baffle covers the outer circumferential surface of the thrust needle roller bearing, preventing oil thrown onto the thrust needle roller bearing from being directly thrown onto the groove wall of the first groove, thus avoiding oil leakage. This allows the thrust needle roller bearing and the first-stage planetary gear set to receive more concentrated oil lubrication, which is beneficial for ensuring the normal operation of the planetary coaxial reducer.

[0030] In one embodiment, the oil collecting baffle includes a first opening and a second opening. The first opening is for communicating with the second opening. The first opening is radially toward the thrust needle roller bearing of the powertrain and is used to receive oil output from the motor shaft oil hole through the gap in the thrust needle roller bearing. The second opening is axially toward the axial hole of the planetary shaft in the first-stage planetary gear set of the powertrain and is used to deliver oil to the axial hole of the planetary shaft in the first-stage planetary gear set.

[0031] In this embodiment, the first opening is radially oriented towards the thrust needle roller bearing of the powertrain. The first opening receives oil output from the motor shaft oil hole through the gap in the thrust needle roller bearing, allowing it to receive oil ejected from the motor shaft oil hole. The second opening is axially oriented towards the axial hole in the planetary shaft of the first-stage planetary gear set. The second opening delivers oil to the axial hole of the planetary shaft in the first-stage planetary gear set, allowing the oil collected by the first opening of the oil collecting baffle to be guided from the second opening into the axial hole of the planetary shaft in the first-stage planetary gear set, thereby lubricating the planetary gears and ensuring the normal operation of the planetary coaxial reducer.

[0032] In one embodiment, the inner wall of the first groove includes an annular protrusion, the inner circumferential surface of which is used to fix the gear ring of the first-stage planetary gear set, and the outer circumferential surface of which is used to fix a bearing of the planet carrier in the second-stage planetary gear set.

[0033] In this embodiment, an annular protrusion on the inner circumferential surface is used to fix the gear ring of the first-stage planetary gear set, and an annular protrusion on the outer circumferential surface is used to fix a bearing of the planet carrier in the second-stage planetary gear set. This allows the bearing of the planet carrier in the second-stage planetary gear set to be arranged around the outer circumference of the gear ring of the first-stage planetary gear set along the circumference of the powertrain. This allows the arrangement of the bearing of the planet carrier in the second-stage planetary gear set to utilize the space of the gear ring of the first-stage planetary gear set along the radial direction of the powertrain, and also allows the arrangement of the bearing of the planet carrier in the second-stage planetary gear set to reuse the space of the gear ring of the first-stage planetary gear set along the axial direction of the powertrain. This results in a compact and more integrated structure of the first-stage and second-stage planetary gear sets in the planetary coaxial reducer, which is beneficial for shortening the axial dimension of the powertrain, miniaturizing the powertrain, and optimizing the layout of the powertrain within the vehicle.

[0034] In one embodiment, one end of the planet carrier in the first-stage planetary gear set is used to fix the sun gear of the second-stage planetary gear set, and the center hole of the planet carrier in the first-stage planetary gear set is used to accommodate another bearing of the planet carrier in the second-stage planetary gear set.

[0035] In this embodiment, one end of the planet carrier in the first-stage planetary gear set is used to fix the sun gear of the second-stage planetary gear set, so that the first-stage planetary gear set can transmit power to the sun gear of the second-stage planetary gear set through the planet carrier in the first-stage planetary gear set, thereby achieving further deceleration.

[0036] In this embodiment, the central hole of the planet carrier in the first-stage planetary gear set is used to accommodate another bearing of the planet carrier in the second-stage planetary gear set. By arranging the other bearing of the planet carrier in the second-stage planetary gear set within the central hole of the planet carrier in the first-stage planetary gear set, the axial space of the central hole of the planet carrier in the first-stage planetary gear set is utilized, making the arrangement of the first-stage and second-stage planetary gear sets more compact. This is beneficial for reducing the axial dimension of the powertrain and can optimize the layout of the powertrain within the vehicle.

[0037] In one embodiment, the planet carrier in the first-stage planetary gear set includes a fixed protrusion that is opposite to the drive motor protrusion. The spline on the outer peripheral surface of the fixed protrusion is used to drive the sun gear of the second-stage planetary gear set. The inner side of the fixed protrusion has a through hole for accommodating another bearing of the planet carrier in the second-stage planetary gear set.

[0038] In this embodiment, the planet carrier in the first-stage planetary gear set includes a fixed protrusion that is away from the drive motor protrusion. This allows the planet carrier in the first-stage planetary gear set to be used to fix the sun gear of the second-stage planetary gear set. This allows the first-stage and second-stage planetary gear sets to be arranged along the axial direction of the powertrain and have a compact structure, which is beneficial for making the axial dimension of the powertrain smaller.

[0039] In this embodiment, the splines on the outer periphery of the fixed protrusion are used to drive the sun gear of the secondary planetary gear set. This allows the projection of the sun gear of the secondary planetary gear set onto the fixed protrusion of the planet carrier in the primary planetary gear set along the radial direction of the powertrain to overlap, resulting in a compact structural arrangement of the primary and secondary planetary gear sets. Furthermore, the fixed protrusion has a through-hole on its inner side to accommodate another bearing of the planet carrier in the secondary planetary gear set. This eliminates the need for the other bearing of the planet carrier in the secondary planetary gear set to occupy additional axial space of the sun gear, thus reducing the axial dimension of the powertrain and optimizing its layout within the vehicle.

[0040] In one embodiment, the planet carrier of the first-stage planetary gear set includes two end plates arranged opposite each other along the axial direction of the powertrain. The space between the two end plates is used to accommodate the planet gears of the first-stage planetary gear set. One end plate includes a through hole through which one end of the motor shaft extends into the space between the two end plates, and multiple teeth of the motor shaft are located between the two end plates. The other end plate includes a fixed protrusion that is axially opposite to the motor shaft protrusion and is used to mount and drive the sun gear in the second-stage planetary gear set.

[0041] In this embodiment, by integrally forming a fixed protrusion on the planet carrier of the first-stage planetary gear set to accommodate and fix the sun gear of the second-stage planetary gear set, the structures of the first-stage and second-stage planetary gear sets are made more compact. This helps to shorten the axial dimension of the planetary coaxial reducer, and consequently, the axial dimension of the powertrain. It also simplifies the transmission structure of the first-stage and second-stage planetary gear sets, thus improving transmission stability.

[0042] In one embodiment, the planet carrier of the second-stage planetary gear set includes two end plates arranged opposite each other along the axial direction of the powertrain. The two end plates are connected by multiple connecting plates, and the space between the two end plates is used to accommodate the planet gears of the second-stage planetary gear set. One end plate includes a through hole through which a fixing protrusion of the planet carrier of the first-stage planetary gear set extends between the two end plates. One end plate also includes a fixing protrusion that protrudes towards the motor shaft along the axial direction of the powertrain. The fixing protrusion is used to mount and drive a bearing of the planet carrier in the second-stage planetary gear set.

[0043] In this embodiment, the fixed protrusion of the planet carrier of the first-stage planetary gear set extends through the perforation between the two end plates, making the structure of the planet carrier of the first-stage planetary gear set and the planet carrier of the second-stage planetary gear set compact, which is beneficial to make the planetary coaxial reducer have a smaller axial dimension.

[0044] In this embodiment, an end plate further includes a fixing protrusion. The fixing protrusion protrudes along the axial direction of the powertrain towards the motor shaft. The fixing protrusion is used to mount and drive a bearing of the planet carrier in the secondary planetary gear set, enabling the planet carrier of the secondary planetary gear set to be drive-connected to a bearing of the planet carrier fixed by the outer circumferential surface of an annular protrusion. The annular protrusion is used to fix the inner ring of the bearing, and the fixing protrusion is used to fix the outer ring of the bearing.

[0045] In one embodiment, the first housing includes two mounting surfaces that are opposite to each other along the axial direction of the drive motor. One of the mounting surfaces is used to abut the mounting surface of the motor housing, and the other mounting surface is used to abut the mounting surface of the second housing. A first groove along the axial direction of the powertrain is recessed from the inner side of the other mounting surface toward the drive motor.

[0046] In this embodiment, the first groove along the axial direction of the powertrain is recessed from the inner side of the other mounting surface toward the drive motor, so that the first housing can utilize the axial space inside the motor housing, making the axial space outside the motor housing occupied by the first housing smaller. This is beneficial to making the overall axial dimension of the planetary coaxial reducer and the drive motor smaller, and to shortening the axial length of the powertrain.

[0047] In one embodiment, the second housing is recessed in the direction away from the drive motor to form a second groove on the side of the second housing facing the drive motor, and the inner wall of the second groove is used to fix the gear ring of the second-stage planetary gear set.

[0048] In this embodiment, the second housing is recessed along the direction away from the drive motor, forming a second groove on the side of the second housing facing the drive motor. This provides sufficient space along the axial direction of the powertrain to accommodate the secondary planetary gear set. The inner wall of the second groove is used to fix the gear ring of the secondary planetary gear set, allowing the planet gears in the secondary planetary gear set to engage with the gear ring fixed to the inner wall of the second groove. This enables the secondary planetary gear set to rotate within the second housing without interference from the second housing.

[0049] In this embodiment, the gear ring of the secondary planetary gear set is fixed inside the second housing, thereby enabling the gear ring of the secondary planetary gear set to be directly assembled with the planetary gears in the secondary planetary gear set when the mounting surface of the second housing is installed with the other mounting surface of the first housing, simplifying the assembly process.

[0050] In one embodiment, the second housing includes a shaft hole that connects the interior and exterior of the reducer housing along the axial direction of the drive motor. The shaft hole is used to receive one end of the planet carrier in the secondary planetary gear set. One end of the planet carrier in the secondary planetary gear set includes an internal spline for driving the half-shaft of the electric vehicle. The half-shaft of the electric vehicle is used to drive the wheels of the electric vehicle.

[0051] In this embodiment, the shaft hole is used to accommodate one end of the planet carrier in the secondary planetary gear set. One end of the planet carrier in the secondary planetary gear set includes an internal spline, so that the half-shaft of the electric vehicle can be directly connected to the planet carrier in the secondary planetary gear set after it extends into the inner side of one end of the planet carrier. This eliminates the need for additional adapters for the transmission between the secondary planetary gear set and the half-shaft of the electric vehicle, thereby reducing the space reserved in the vehicle assembly for the transmission connection between the powertrain and the half-shaft of the electric vehicle, and optimizing the layout of the powertrain in the vehicle.

[0052] In the embodiments of this application, the planet carrier in the secondary planetary gear set is directly connected to the half-shaft of the electric vehicle, which is also beneficial to reduce the radial and axial movement of the half-shaft of the electric vehicle during transmission, and to improve the NVH performance of the whole vehicle.

[0053] In one embodiment, the planet carrier in the second-stage planetary gear set includes a half-shaft protrusion that is axially opposite to the first-stage planetary gear set protrusion along the powertrain axis. The half-shaft protrusion is for passing through a shaft hole and has an internal spline.

[0054] In this embodiment, the planet carrier in the secondary planetary gear set includes a half-shaft protrusion. This half-shaft protrusion is axially opposite to the primary planetary gear set protrusion along the powertrain axis, creating a space within one end of the planet carrier in the secondary planetary gear set for an internal spline. This allows the half-shaft of the electric vehicle to extend into this space and connect with the internal spline for transmission. The fact that the half-shaft protrusion is axially opposite to the primary planetary gear set protrusion also facilitates its exit from the shaft hole of the second housing, allowing the internal spline of the half-shaft protrusion to more easily connect with the half-shaft of the electric vehicle.

[0055] Secondly, this application provides a powertrain including a planetary reducer and a drive motor. The reducer housing of the powertrain accommodates two planetary gear sets of the planetary reducer. One planetary gear set is used to drive the motor shaft of the drive motor. The planet carrier of one planetary gear set is used to drive the sun gear in the other planetary gear set. The planet carrier in the other planetary gear set is used to drive the half-shaft of the wheel of an electric vehicle. The planet shaft of each planetary gear set includes a communicating axial bore and a radial bore. The radial bore is used to output oil received in the axial bore to the bearing of the planet shaft for lubrication. The planet carrier of one planetary gear set is spaced from the inner wall of the reducer housing. The space between the planet carrier of one planetary gear set and the inner wall of the reducer housing is used to transfer the oil output from the radial bore of the planet carrier of one planetary gear set to the axial bore of the planet shaft of the other planetary gear set.

[0056] In this embodiment, oil flows from one planetary gear set to another, enabling oil to flow and lubricate in the two-stage planetary gear sets. This reduces the oil circuit structure of the reducer housing and simplifies the powertrain oil circuit design.

[0057] In one embodiment, the reducer housing includes a first housing and a second housing, the first housing surrounding the second housing, the first housing including a groove with the opening of the groove facing the second housing, wherein:

[0058] The groove wall is used to fix the gear ring of a planetary gear set. The planet carrier of a planetary gear set is spaced from the groove wall. The gap between the planet carrier of a planetary gear set and the groove wall is used to transfer the oil output from the radial hole of the planet carrier of one planetary gear set to the axial hole of the planet shaft of another planetary gear set.

[0059] In this embodiment of the application, by spacing the planet carrier of a planetary gear set from the groove wall, the oil that lubricates one planetary gear set can flow from the planet carrier of one planetary gear set to another planetary gear set through the gap between the planet carrier and the groove wall for lubrication, thus achieving oil reuse.

[0060] In one embodiment, the inner diameter of the gear ring of another planetary gear set is larger than the inner diameter of the gear ring of one planetary gear set, and the opening of the axial hole of the planet shaft of the other planetary gear set faces the gap between the planet carrier of one planetary gear set and the groove wall of the groove.

[0061] In the embodiment of the application, when the planet carrier and planet gears of a planetary gear set rotate, they throw oil out circumferentially. By making the inner diameter of the gear ring of another planetary gear set larger than the inner diameter of the gear ring of the first planetary gear set, the axial holes of the planet shaft of the first planetary gear set are distributed on the outer periphery of the planet carrier of the first planetary gear set, which facilitates the reception of the oil thrown out by the first planetary gear set.

[0062] In one embodiment, one end of the motor shaft extends into the groove, and the one end of the motor shaft serves as the sun gear of the first-stage planetary gear set. The one end of the motor shaft includes a motor shaft oil hole. The groove is also used to accommodate a thrust needle roller bearing and an oil collecting baffle. The thrust needle roller bearing is used to rotatably connect the planet carrier and the first housing of the first-stage planetary gear set. The thrust needle roller bearing surrounds the outer periphery of the motor shaft oil hole. The gap in the thrust needle roller bearing is used to transmit the oil output from the motor shaft oil hole to the opening of the planet shaft of the first-stage planetary gear set.

[0063] An oil baffle surrounds the outer periphery of the thrust needle roller bearing. The oil baffle is used to cover the outer peripheral surface of the thrust needle roller bearing and the opening of the axial hole of the planetary shaft in the first-stage planetary gear set, and to connect the clearance of the outer peripheral surface of the thrust needle roller bearing and the opening of the axial hole of the planetary shaft in the first-stage planetary gear set.

[0064] In this embodiment, the clearance in the thrust needle roller bearing is used to transmit oil from the motor shaft oil hole to the axial bore opening of the planetary shaft of the first-stage planetary gear set. This allows the oil collecting baffle to guide the oil thrown out of the motor shaft oil hole into the axial bore opening of the planetary shaft of the first-stage planetary gear set, thereby lubricating the planetary gears of the first-stage planetary gear set. The oil collecting baffle covers the outer circumferential surface of the thrust needle roller bearing, preventing oil thrown onto the thrust needle roller bearing from being directly thrown onto the groove wall of the first groove, thus avoiding oil leakage. This allows the thrust needle roller bearing and the first-stage planetary gear set to receive more concentrated oil lubrication, which is beneficial for ensuring the normal operation of the planetary coaxial reducer.

[0065] In one embodiment, the planet carrier of another planetary gear set includes a half-shaft bore and a plug. One opening of the half-shaft bore faces one planetary gear set, and the other opening of the half-shaft bore is for extending out of a second housing and for inserting a half-shaft of a wheel. The plug is used to block one opening of the half-shaft bore and a central bore of the planet carrier for rotatable connection to one planetary gear set. The plug includes a thrust bearing groove and a positioning groove. The thrust bearing groove is used to receive a thrust bearing, which is used to rotatably connect the sun gear of the other planetary gear set and the plug. The opening of the positioning groove along the axial direction of the powertrain faces away from one planetary gear set. The positioning groove is used to receive a portion of the half-shaft and restrict the half-shaft's radial movement along the powertrain. The inner diameter of the positioning groove is smaller than the inner diameter of the half-shaft bore. The thrust bearing groove surrounds the outer periphery of the positioning groove. Along the radial direction of the powertrain, the projection of the positioning groove at least partially overlaps with that of the thrust bearing groove.

[0066] In this embodiment of the application, by extending the half-shaft through the slot of the positioning groove into the positioning groove of the sealing member, compared with positioning the half-shaft outside the reducer housing and the planetary reducer, the axial length between the rotor of the drive motor and the half-shaft can be shortened, the power transmission stability can be improved, and the critical speed of the rotor can be increased.

[0067] In this embodiment, the inner diameter of the positioning groove is smaller than the inner diameter of the half-shaft hole. The positioning groove is used to accommodate a part of the half-shaft of the wheel and restrict the half-shaft from moving radially along the powertrain. This helps to make the transmission between the other planetary gear set and the half-shaft of the wheel more stable and improves the reliability of the powertrain.

[0068] Thirdly, this application provides an electric vehicle, which includes a frame and a powertrain as described in the first and second aspects. The frame is used to fix the powertrain, and the drive motor of the powertrain is used to receive power from a power battery to drive the wheels through a planetary reducer.

[0069] In the powertrain of this application embodiment, the motor rotor and the gear set of the first-stage planetary gear set are arranged inside the motor housing on both sides of the bearing of the motor shaft along the axial direction of the drive motor. The gear set of the first-stage planetary gear set is arranged inside the motor housing, making full use of the space inside the motor housing. This makes the planetary coaxial reducer and the drive motor compactly arranged, so that the arrangement of the first-stage planetary gear set of the planetary coaxial reducer does not occupy additional axial space of the powertrain, thereby shortening the axial dimension of the powertrain, miniaturizing the powertrain, and facilitating the layout of the powertrain in the vehicle. Attached Figure Description

[0070] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0071] Figure 1 is a schematic diagram of an electric vehicle provided in an embodiment of this application;

[0072] Figure 2 is a schematic diagram of a powertrain provided in an embodiment of this application;

[0073] Figure 3 is a cross-sectional view of a powertrain provided in an embodiment of this application;

[0074] Figure 4 is a cross-sectional view of the planetary reducer and motor shaft provided in an embodiment of this application;

[0075] Figure 5 is a schematic diagram of a planetary reducer provided in an embodiment of this application;

[0076] Figure 6 is an exploded view of the planetary reducer in Figure 5;

[0077] Figure 7 is another schematic diagram of the powertrain provided in an embodiment of this application;

[0078] Figure 8 is a schematic diagram of a first housing provided in an embodiment of this application;

[0079] Figure 9 is a partial enlarged view of the M1 part of the powertrain in Figure 3;

[0080] Figure 10 is another schematic diagram of the first housing provided in an embodiment of this application;

[0081] Figure 11 is an exploded view of a sensor bracket and a resolver sensor provided in an embodiment of this application;

[0082] Figure 12 is a partial enlarged view of the M2 section of the planetary reducer and motor shaft in Figure 4;

[0083] Figure 13 is a schematic diagram of a first-stage planetary gear set provided in an embodiment of this application;

[0084] Figure 14 is a schematic diagram of a two-stage planetary gear set provided in an embodiment of this application;

[0085] Figure 15 is a partial enlarged view of the M3 section of the planetary reducer and motor shaft in Figure 4;

[0086] Figure 16 is a schematic diagram of a motor shaft provided in an embodiment of this application;

[0087] Figure 17 is a cross-sectional view of the motor shaft and oil guide pipe provided in an embodiment of this application;

[0088] Figure 18 is a partial enlarged view of the M4 section of the powertrain in Figure 3. Detailed Implementation

[0089] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0090] For ease of understanding, the English abbreviations and related technical terms used in the embodiments of this application will be explained and described below.

[0091] NVH is an abbreviation for Noise, Vibration, and Harshness, which refers to noise, vibration, and acoustic roughness.

[0092] This application provides a powertrain with a two-stage planetary coaxial reducer for driving an electric vehicle. The powertrain housing includes a motor housing and a reducer housing. The motor housing houses the stator of the drive motor, and the central hole of the stator houses the rotor. The reducer housing houses the first-stage and second-stage planetary gear sets of the planetary coaxial reducer. The first-stage planetary gear set is used to drive the second-stage planetary gear set and the motor shaft of the drive motor. The second-stage planetary gear set is used to drive the wheels of the electric vehicle. The motor housing secures the reducer housing, and the reducer housing encloses the opening of the motor housing and the bearings for fixing the motor shaft. The motor rotor and the gear sets of the first-stage planetary gear set are arranged inside the motor housing on both sides of the bearings along the axial direction of the drive motor.

[0093] By arranging the motor rotor and the gear set of the first-stage planetary gear set inside the motor housing on both sides of the motor shaft bearing along the axial direction of the drive motor, the space inside the motor housing is fully utilized, making the planetary coaxial reducer and drive motor compactly arranged. This ensures that the arrangement of the first-stage planetary gear set of the planetary coaxial reducer does not occupy additional axial space of the powertrain, thereby shortening the axial dimension of the powertrain, miniaturizing the powertrain, and facilitating the layout of the powertrain within the vehicle.

[0094] This application provides a powertrain that is applied to an electric vehicle.

[0095] Figure 1 is a schematic diagram of an electric vehicle 1 provided in an embodiment of this application.

[0096] In one embodiment, the electric vehicle 1 includes a frame 10, a powertrain 20, and a power battery 30, as shown in FIG1. ​​The frame 10 is used to fix the powertrain 20 and the power battery 30. In this embodiment, the electric vehicle 1 refers to a wheeled device driven or towed by a power unit. In this embodiment, the powertrain 20 is used to drive the wheels 40.

[0097] Figure 2 is a schematic diagram of a powertrain 20 provided in an embodiment of this application, and Figure 3 is a cross-sectional view of a powertrain 20 provided in an embodiment of this application.

[0098] In one embodiment, as shown in FIG2, the powertrain 20 includes a motor controller 100, a drive motor 200, and a reducer 300.

[0099] In this embodiment, as shown in Figures 2 and 3, the drive motor 200 includes a motor shaft 210, a motor stator 220, and a motor rotor 230, while the reducer 300 includes a gear set. The motor controller 100 receives power from the power battery 30. The motor rotor 230 in the drive motor 200 is fixedly mounted on the motor shaft 210. After receiving current from the motor controller 100, the motor stator 220 drives the motor rotor 230 to rotate, thereby causing the motor shaft 210 to rotate. The motor shaft 210 of the drive motor 200 transmits kinetic energy to the gear set of the reducer 300, and then transmits power to the wheel 40 through the half-shaft, driving the wheel 40 to move.

[0100] In one embodiment, the stator 220 of the drive motor 200 includes a stator core 221 and a stator winding 222. Along the axial direction O of the powertrain 20, the end winding 2220 is exposed on one side of the stator core 221. The end winding 2220 is connected to the motor controller 100 through the outgoing copper busbar 240 to receive three-phase AC power, thereby driving the rotor 230 of the motor 200 to rotate.

[0101] Figure 4 is a cross-sectional view of the planetary reducer 300 and motor shaft 210 provided in an embodiment of this application. Figure 5 is a schematic diagram of the planetary reducer 300 provided in an embodiment of this application. Figure 6 is an exploded view of the planetary reducer 300 in Figure 5.

[0102] In one embodiment, as shown in FIG4, the reducer 300 is a planetary reducer 300, which can also be called a planetary coaxial reducer 300. When the planetary reducer 300 is a single-stage planetary reducer 300, the gear set of the planetary reducer 300 includes a planetary gear set 310. The planetary gear set 310 includes a sun gear 311, multiple planetary gears 312, a ring gear 313, a planet carrier 314, and multiple planetary shafts 315. The sun gear 311 of the planetary gear set 310 is connected to the motor shaft 210 of the drive motor 200, and the planet carrier 314 is connected to the half-shaft of the wheel. The half-shaft of the wheel is coaxially arranged with the motor shaft 210 of the drive motor 200.

[0103] In one embodiment, the planet carrier of the planetary reducer 300 is directly driven to the half-shaft 50 of the wheel 40 of the electric vehicle 1.

[0104] In one embodiment, as shown in Figures 4 to 6, to achieve a large speed ratio in the planetary reducer 300 and meet the deceleration requirements of the electric vehicle 1, the planetary reducer 300 is either a two-stage planetary reducer 300 or a two-stage coaxial planetary reducer 300. The gear set of the planetary reducer 300 includes two planetary gear sets 310 and 320. One planetary gear set 310 and the other planetary gear set 320 are arranged along the axial direction O of the powertrain 20. One planetary gear set 310, which is connected to the motor shaft 210 of the drive motor 200, is also called the first-stage planetary gear set 310. The other planetary gear set 320, which is connected to the first-stage planetary gear set 310 and the half-shaft 50 of the electric vehicle 1, is also called the second-stage planetary gear set 320. A significant speed reduction is achieved through the two-stage planetary gear sets 310 and 320.

[0105] In one embodiment, as shown in Figures 4 to 6, the sun gear 311 of the first-stage planetary gear set 310 is used to drive the motor shaft 210 of the drive motor 200 and the planet gears 312 of the first-stage planetary gear set 310. The planet gears 312 of the first-stage planetary gear set 310 are used to mesh with the ring gear 313 of the first-stage planetary gear set 310. The planet carrier 314 of the first-stage planetary gear set 310 is used to fix the planet shaft 315 passing through the multiple planet gears 312 of the first-stage planetary gear set 310. The planet carrier 321 of the second-stage planetary gear set 320 is used to fix the planet shaft of the second-stage planetary gear set 320. The sun gear 323 of the second-stage planetary gear set 320 is used to mesh with the planet gears 324 of the second-stage planetary gear set 320. The planet gears 324 of the second-stage planetary gear set 320 mesh with the ring gear 322 of the second-stage planetary gear set 320 and the planet carrier 314 of the first-stage planetary gear set 310.

[0106] In one embodiment, as shown in FIG3, the housing 20a of the powertrain 20 includes a motor housing 400 and a reducer housing 500. The motor housing 400 is used to fix the stator 220 of the drive motor 200 and to house the rotor 230 of the drive motor 200. The central hole 223 of the stator 220 is used to house the rotor 230 of the drive motor 200. The reducer housing 500 is used to house the gear set of the planetary reducer 300. The motor housing 400 and the reducer housing 500 are arranged along the axial direction O of the powertrain 20. The reducer housing 500 can be divided into a first housing 510 and a second housing 520. The first housing 510 is used to enclose the motor housing 400 to form a motor cavity 400a, and the second housing 520 is used to enclose the first housing 510 to form a reducer cavity 500a. In one embodiment, the stator 220 of the drive motor 200 can also be referred to as a motor stator 220, and the rotor 230 of the drive motor 200 can also be referred to as a motor rotor 230.

[0107] In one embodiment, the powertrain 20 includes two drive motors 200 and two planetary reducers 300, as shown in FIG3. Along the axial direction O of the powertrain 20, the two planetary reducers 300 are respectively arranged on both sides of the two drive motors 200. The stator 220 of each drive motor 200 is used to receive current from the power battery 30 to rotate the rotor 230 of the drive motor 200, and transmits power to one planetary reducer 300 through the motor shaft 210, thereby driving the wheel 40 on one side of the electric vehicle 1 to move. The operation of the wheels 40 on both sides of the electric vehicle 1 is controlled by the two drive motors 200 and the two planetary reducers 300 respectively.

[0108] In one embodiment, the motor shaft 210 includes an internal oil passage 216, as shown in FIG3. The internal oil passage 216 of the motor shaft 210 is used to receive oil delivered by the internal oil passage of the housing 20a of the powertrain 20. The oil in the internal oil passage 216 of the motor shaft 210 is used to cool the rotor 230 of the drive motor 200 and lubricate the gear set of the planetary reducer 300, so that the planetary reducer 300 can operate normally.

[0109] The powertrain 20 provided in the embodiments of this application will be described in detail below.

[0110] Figure 7 is another schematic diagram of the powertrain 20 provided in an embodiment of this application, and Figure 8 is a schematic diagram of the first housing 510 provided in an embodiment of this application.

[0111] In one embodiment, as shown in Figures 3, 6, and 7, the powertrain 20 includes a motor housing 400 and a first housing 510. The motor housing 400 is used to fix the stator 220 of the drive motor 200 and to house the rotor 230 of the drive motor 200. The motor shaft 210 of the drive motor 200 is used to drively connect the planetary gear set 310 of the planetary reducer 300. The first housing 510 is used to enclose the opening 401 of the motor housing 400. As shown in Figure 3, along the axial direction O of the powertrain 20, the end winding 2220 of the stator 220 is exposed on one side of the stator core 221 of the stator 220, and the end winding 2220 surrounds the outer periphery of the motor shaft 210 of the drive motor 200 along the circumferential direction C of the powertrain 20. As shown in Figures 6 to 8, a groove 511 is formed by recessing the first housing 510 toward the inner region 2221 surrounded by the end winding 2220 along the axial direction O of the powertrain 20. The groove 5110 of the groove 511 is away from the rotor 230 of the drive motor 200. The groove 511 is used to accommodate the planetary gear set 310 of the planetary reducer 300.

[0112] In this embodiment, the end winding 2220 of the stator 220 along the axial direction O of the powertrain 20 is exposed on one side of the stator core 221 of the stator 220. The end winding 2220 surrounds the outer periphery of the motor shaft 210 of the drive motor 200 along the circumferential direction C of the powertrain 20, so that the end winding 2220 along the axial direction O of the powertrain 20 and the rotor 230 of the drive motor 200 can form a slot-like space, which makes it possible for the first housing 510 to be recessed toward the inner space of the end winding 2220.

[0113] In this embodiment, along the axial direction O of the powertrain 20, the first housing 510 is recessed towards the inner region 2221 surrounded by the end winding 2220 to form a groove 511, such that a portion of the first housing 510 forming the groove 511 can extend into the inner region 2221 surrounded by the end winding 2220. This allows the arrangement of the first housing 510 in the powertrain 20 to reuse part of the axial and radial space of the end winding 2220 of the stator 220 of the drive motor 200, which is beneficial to reducing the axial dimension of the powertrain 20.

[0114] In this embodiment, the slot 5110 of the groove 511 is away from the rotor 230 of the drive motor 200, so that after the first housing 510 is fixed to the motor housing 400, the planetary gear set 310 of the planetary reducer 300 can be assembled into the first housing 510 from the slot 5110 side of the groove 511, which facilitates the assembly process.

[0115] In this embodiment, the groove 511 is used to accommodate the planetary gear set 310 of the planetary reducer 300, so that a part of the planetary gear set 310 of the planetary reducer 300 can extend into the motor housing 400. This allows the planetary reducer 300 to be arranged using the axial space in the inner region 2221 surrounded by the end winding 2220, making the arrangement of the planetary gear set 310 of the planetary reducer 300 and the rotor 230 and stator 220 of the drive motor 200 more compact. This is beneficial to make the overall size of the planetary reducer 300 and the drive motor 200 along the axial direction O of the powertrain 20 smaller, so that the powertrain 20 has a smaller volume and optimizes the layout of the powertrain 20 in the vehicle.

[0116] In this embodiment, a groove 511 is formed by recessing the inner region 2221 of the first housing 510 surrounding the end winding 2220 of the stator 220, and the planetary gear set 310 of the planetary reducer 300 is accommodated in the groove 511. This design of the groove 511 of the first housing 510 makes full use of the space inside the axial and radial end winding 2220 along the powertrain 20. It also allows the arrangement of the planetary gear set 310 of the planetary reducer 300 in the groove 511 to reuse part of the axial and radial space inside the end winding 2220. This is beneficial to making the axial dimension of the powertrain 20 smaller, which is beneficial to the miniaturization of the powertrain 20 and optimizes the layout of the powertrain 20 in the vehicle.

[0117] Figure 9 is a partial enlarged view of the M1 part of the powertrain 20 in Figure 3.

[0118] In one embodiment, as shown in Figures 3, 7 and 9, the end winding 2220 is housed within the motor housing 400. Along the axial direction O of the powertrain 20, the end winding 2220 is spaced from the opening 401 of the motor housing 400. Along the axial direction O of the powertrain 20, the first housing 510 protrudes from the opening 401 of the motor housing 400 toward the inner region 2221 surrounded by the end winding 2220. The surface of the first housing 510 facing away from the rotor 230 of the drive motor 200 is recessed to form a groove 511.

[0119] In this embodiment, the end winding 2220 is housed within the motor housing 400. Along the axial direction O of the powertrain 20, the end winding 2220 is spaced from the opening 401 of the motor housing 400, creating space within the motor housing 400 for the first housing 510 to protrude into the inner region 2221 surrounded by the end winding 2220. This arrangement of the first housing 510 utilizes not only part of the axial and radial space of the end winding 2220, but also the space between the end winding 2220 and the motor housing 400. The axial space between the openings 401 allows the planetary reducer 300 to make full use of the axial space within the motor housing 400, ensuring that the planetary reducer 300 does not occupy too much space in the motor housing 400 outside the axial direction O of the powertrain 20. It also makes the planetary gear set 310 of the planetary reducer 300 and the stator 220 and rotor 230 of the drive motor 200 arranged compactly, which is beneficial for the powertrain 20 to have a smaller axial dimension, which is beneficial for the miniaturization of the powertrain 20 and optimizes the layout of the powertrain 20 in the whole vehicle.

[0120] In this embodiment, the surface of the first housing 510 facing away from the rotor 230 of the drive motor 200 is recessed to form a groove 511. The groove 511 is used to accommodate the planetary gear set 310 of the planetary reducer 300, so that the arrangement of the planetary gear set 310 of the planetary reducer 300 can make full use of the axial space of the motor housing 400, and the planetary gear set 310 can be arranged in the motor housing 400 along the radial R direction of the powertrain 20. This is beneficial to making the axial dimension of the powertrain 20 smaller, which is beneficial to the miniaturization of the powertrain 20 and optimizes the layout of the powertrain 20 in the whole vehicle.

[0121] In one embodiment, as shown in FIG3, the inner diameter of the radial groove 511 along the powertrain 20 is smaller than the inner diameter of the inner circumferential side surrounded by the end winding 2220. This allows the first housing 510 to recess into the inner region 2221 surrounded by the end winding 2220 to form the groove 511, thereby enabling the arrangement of the planetary reducer 300 to reuse a portion of the space of the inner region 2221 surrounded by the end winding 2220 along the axial direction O of the powertrain 20, resulting in a smaller axial dimension of the powertrain 20.

[0122] In one embodiment, as shown in Figures 3, 8 and 9, a portion of the first housing 512 along the axial direction of the powertrain 20 is used to be embedded in the inner region 2221 surrounded by the end winding 2220, and the surface of the portion of the first housing 512 along the axial direction of the powertrain 20 away from the rotor 230 of the drive motor 200 forms the bottom 5111 of the groove 511.

[0123] In this embodiment, a portion of the first housing 512 along the axial direction O of the powertrain 20 is embedded in the inner region 2221 surrounded by the end winding 2220. This allows the arrangement of a portion of the first housing 512 to utilize the axial space of the inner region 2221 surrounded by the end winding 2220. This facilitates a more compact arrangement of the planetary gear set 310 of the planetary reducer 300 and the stator 220 of the drive motor 200, resulting in a smaller overall axial dimension of the planetary reducer 300 and the drive motor 200, thereby reducing the axial dimension of the powertrain 20.

[0124] In this embodiment, a portion of the surface of the first housing 512 facing away from the rotor 230 of the drive motor 200 along the axial direction O of the powertrain 20 forms the groove bottom 5111 of the groove 511. This allows the groove bottom 5111 of the groove 511 to be located in the inner region 2221 surrounded by the end winding 2220, making full use of the axial and radial space of the inner region 2221 surrounded by the end winding 2220. This makes the arrangement of the first housing 510 and the end winding 2220 more compact and is more conducive to shortening the axial dimension of the powertrain 20.

[0125] In one embodiment, as shown in FIG3, the length of the first housing 510 along the axial direction O of the powertrain 20 is greater than the distance between the opening 401 of the motor housing 400 and the end winding 2220.

[0126] In this embodiment, the length of the first housing 510 along the axial direction O of the powertrain 20 is relatively large, so that the length of the first housing 510 is long enough that a portion of the first housing 512 can extend from the opening 401 of the motor housing 400 into the inner region 2221 surrounded by the end winding 2220, making full use of the inner space of the end winding 2220, thereby making the overall axial dimension of the planetary reducer 300 and the drive motor 200 smaller, and making the axial dimension of the powertrain 20 smaller.

[0127] In one embodiment, as shown in Figures 7 and 9, the end winding 2220 is connected to the motor controller 100 via the outgoing copper busbar 240 to receive three-phase AC power. Along the axial direction O of the powertrain 20, the outgoing copper busbar 240 extends from the end winding 2220 away from the stator core 221. Along the radial direction R of the powertrain 20, another part of the first housing 513 is used to be embedded between the outgoing copper busbar 240 and the motor shaft 210. Along the radial direction R of the powertrain 20, the surface of the other part of the first housing 513 away from the outgoing copper busbar 240 forms a portion of the groove peripheral wall 5113 of the groove 511.

[0128] In this embodiment, another portion of the first housing 513 along the radial direction R of the powertrain 20 is used to embed between the copper busbar 240 and the motor shaft 210, so that the arrangement of the other portion of the first housing 513 can make full use of the space between the copper busbar 240 and the motor shaft 210 along the radial direction R of the powertrain 20, and the arrangement of the other portion of the first housing 513 can utilize part of the axial space of the motor housing 400, which is beneficial to making the axial dimension of the powertrain 20 smaller.

[0129] In this embodiment, a portion of the first housing 513 along the radial direction R of the powertrain 20 forms a groove 511 on the surface opposite to the lead wire bus 240. The groove 511 is used to accommodate the planetary gear set 310 of the planetary reducer 300. This allows the arrangement of the planetary gear set 310 of the planetary reducer 300 to utilize the space between the lead wire bus 240 and the motor shaft 210 along the radial direction R of the powertrain 20. This makes the arrangement of the planetary reducer 300 and the lead wire bus 240 more compact, which is beneficial for making the layout of the planetary reducer 300, the lead wire bus 240 and the end winding 2220 along the axial direction O and the radial direction R of the powertrain 20 more compact, thus contributing to the miniaturization of the powertrain 20.

[0130] In one embodiment, as shown in Figures 3 and 9, the depth of the groove 511 along the axial direction of the powertrain 20 is greater than the distance between the opening 401 of the motor housing 400 and the copper busbar 240.

[0131] In this embodiment, the depth of the groove 511 along the axial direction O of the powertrain 20 is relatively large, making the groove 511 deep enough to accommodate multiple planetary gears 312 in the planetary gear set 310. This allows the planetary gear set 310 to be arranged in the inner area of ​​the end winding 2220 or the outgoing copper busbar 240. The arrangement of the planetary gear set 310 of the planetary reducer 300 utilizes part of the internal axial space of the motor housing 400, so that the planetary reducer 300 does not occupy too much space of the motor housing 400 outside the axial direction O of the powertrain 20, and the axial dimension of the powertrain 20 is smaller.

[0132] Figure 10 is another schematic diagram of the first housing 510 provided in an embodiment of this application.

[0133] In one embodiment, as shown in Figures 9 and 10, the first housing 510 further includes a motor shaft bearing groove 514, which is used to fix the outer ring of the motor bearing 5141 and the inner ring of the motor bearing 5141 is used to fix the motor shaft 210. Along the axial direction of the powertrain 20, the groove opening 5142 of the motor shaft bearing groove 514 faces away from the groove opening 5110 of the recess 511. The groove opening 5142 of the motor shaft bearing groove 514 is used to be embedded in the inner region 2221 surrounded by the end winding 2220.

[0134] In this embodiment, the groove 5142 of the motor shaft bearing groove 514 along the axial direction of the powertrain 20 faces away from the groove 5110 of the recess 511. This allows the arrangement of the motor shaft bearing groove 514 accommodating the motor bearing 5141 to utilize part of the wall thickness of the groove bottom 5111 of the recess 511, and also allows the motor bearing 5141 to be arranged closer to the rotor 230 of the drive motor 200, making it easier to fix the motor bearing 5141 to the motor shaft 210. Furthermore, since the recess 511 is formed on the left side of the first housing 510 to accommodate the planetary reducer 300, the motor shaft bearing groove 514 needs to be formed on the right side of the first housing 510 to fix the motor bearing 5141. Therefore, it is required that the groove 5142 of the motor shaft bearing groove 514 along the axial direction of the powertrain 20 faces away from the groove 5110 of the recess 511.

[0135] In this embodiment, the slot 5142 of the motor shaft bearing groove 514 is used to be embedded in the inner region 2221 surrounded by the end winding 2220, so that both the motor shaft bearing groove 514 and the motor bearing 5141 can extend into the inner region 2221 surrounded by the end winding 2220. This allows the motor bearing 5141 to be arranged using part of the space in the inner region 2221 surrounded by the end winding 2220 of the stator 220 of the drive motor 200, which is beneficial to reducing the axial dimension of the powertrain 20.

[0136] In one embodiment, as shown in Figures 3 and 9, the distance between the slot 5142 of the motor shaft bearing groove 514 and the slot 5110 of the recess 511 along the axial direction O of the powertrain 20 is greater than the distance between the opening 401 of the motor housing 400 and the copper busbar 240. The outer diameter of the portion of the first housing 510 corresponding to the motor shaft bearing groove 514 along the radial direction R of the powertrain 20 is smaller than the outer diameter of the end winding 2220.

[0137] In this embodiment, the distance between the slot 5142 of the motor shaft bearing groove 514 and the slot 5110 of the groove 511 along the axial direction of the powertrain 20 is greater than the distance between the opening 401 of the motor housing 400 and the copper busbar 240. Since the groove 511 is formed on the left side of the first housing 510 to accommodate the planetary reducer 300, the motor shaft bearing groove 514 needs to be formed on the right side of the first housing 510 to fix the motor bearing 5141. The distance between the slot 5142 of the motor shaft bearing groove 514 and the slot 5110 of the groove 511 is designed to be larger, so that the motor bearing 5141 can extend into the inner area 2221 surrounded by the end winding 2220, making full use of the inner area of ​​the end winding 2220, which is beneficial to make the axial dimension of the powertrain 20 smaller.

[0138] In this embodiment, the outer diameter of the portion of the first housing 510 corresponding to the radial R motor shaft bearing groove 514 of the powertrain 20 is smaller than the outer diameter of the end winding 2220, so that the outer wall of the motor shaft bearing groove 514 can extend into the inner region 2221 surrounded by the end winding 2220, thereby allowing the motor bearing 5141 to extend into the inner region 2221 surrounded by the end winding 2220.

[0139] In one embodiment, as shown in FIG3, the motor housing 400 is used to fix the reducer housing 500 of the powertrain 20. The reducer housing 500 is used to enclose the opening 401 of the motor housing 400 and the bearing 5141 for fixing the motor shaft 210. As shown in FIG3 and FIG9, the gear set of the motor rotor 230 and the first-stage planetary gear set 310 are arranged inside the motor housing 400 on both sides of the bearing 5141 of the motor shaft 210 along the axial direction O of the drive motor 200.

[0140] In this embodiment, the motor housing 400 is used to fix the reducer housing 500 of the powertrain 20. The reducer housing 500 is used to enclose the opening 401 of the motor housing 400 and the bearing 5141 for fixing the motor shaft 210, so that the reducer housing 500 and the motor housing 400 can be arranged along the axial direction O of the powertrain 20.

[0141] In this embodiment of the application, since the planetary coaxial reducer 300 includes a first-stage planetary gear set 310 and a second-stage planetary gear set 320, the axial length of the planetary coaxial reducer 300 is relatively long. This makes it easy for the axial dimension of the powertrain 20 to be large when the planetary coaxial reducer 300 and the drive motor 200 are arranged along the axial direction O of the drive motor 200, which is not conducive to the miniaturization of the powertrain 20. The gear sets of the motor rotor 230 and the first-stage planetary gear set 310 are arranged inside the motor housing 400 on both sides of the bearing 5141 of the motor shaft 210 along the axial direction O of the drive motor 200. The arrangement of the gear sets of the first-stage planetary gear set 310 inside the motor housing 400 makes full use of the space inside the motor housing 400. It also allows the planetary coaxial reducer 300 to be arranged compactly with the drive motor 200. The arrangement of the first-stage planetary gear set 310 of the planetary coaxial reducer 300 does not occupy additional space outside the motor housing 400 along the axial direction O of the drive motor 200. This shortens the axial dimension of the powertrain 20, miniaturizes the powertrain 20, and optimizes the layout of the powertrain 20 in the vehicle.

[0142] In one embodiment, the bearing 5141 of the motor shaft 210 may also be referred to as the motor bearing 5141.

[0143] In one embodiment, as shown in Figures 7 and 9, the motor housing 400 surrounds the end winding 2220 of the motor stator 220 on the side facing the planetary coaxial reducer 300, and the end winding 2220 of the motor stator 220 on the side facing the planetary coaxial reducer 300 surrounds the bearing 5141 of the motor shaft 210 along the circumferential direction C of the powertrain 20.

[0144] In this embodiment, the motor housing 400 surrounds the end winding 2220 of the motor stator 220 facing the planetary coaxial reducer 300, such that the end winding 2220 of the motor stator 220 facing the planetary coaxial reducer 300 is arranged in the motor housing 400 along the axial direction O of the powertrain 20, without occupying additional space in the motor housing 400 outside the axial direction of the powertrain 20. The end winding 2220 of the motor stator 220 facing the planetary coaxial reducer 300 surrounds the bearing 5141 of the motor shaft 210 along the circumferential direction C of the powertrain 20. This allows the bearing 5141 of the motor shaft 210 to be arranged within the end winding 2220 facing the planetary coaxial reducer 300 along the radial direction R and axial direction O of the powertrain 20. This arrangement of the bearing 5141 of the motor shaft 210 can make full use of the space inside the end winding 2220, making the arrangement of the bearing 5141 of the motor shaft 210 and the motor rotor 230 more compact, thereby shortening the axial dimension of the powertrain 20.

[0145] Figure 11 is an exploded view of the sensor bracket 610 and the resolver sensor 620 provided in an embodiment of this application.

[0146] In one embodiment, as shown in Figures 9 and 11, the first housing 510 is also used to fix the sensor bracket 610, which is used to fix the stator 621 of the resolver sensor 620. Along the axial direction O of the powertrain 20, the first housing 510, the sensor bracket 610 and the rotor 230 of the drive motor 200 are arranged in sequence, and the sensor bracket 610 is used to be embedded in the inner region 2221 surrounded by the end winding 2220.

[0147] In this embodiment, along the axial direction O of the powertrain 20, the groove 511 on the side of the first housing 510 away from the rotor 230 of the drive motor 200 is used to accommodate the planetary gear set 310 of the planetary reducer 300, so that the space on the side of the first housing 510 away from the rotor 230 is occupied. The stator 621 of the resolver sensor 620 is installed between the first housing 510 and the rotor 230 of the drive motor 200, so that the first housing 510, the sensor bracket 610 and the rotor 230 of the drive motor 200 are arranged sequentially along the axial direction O of the powertrain 20, making full use of the space on both sides of the first housing 510.

[0148] In this embodiment, the sensor bracket 610 is embedded in the inner region 2221 surrounded by the end winding 2220, so that the sensor bracket 610 can be disposed in the inner region 2221 surrounded by the end winding 2220. This ensures that the arrangement of the sensor bracket 610 does not occupy additional space in the inner region 2221 surrounded by the end winding 2220 outside the axial direction of the powertrain 20, which is beneficial for the powertrain 20 to have a smaller axial dimension.

[0149] In one embodiment, as shown in FIG9, the distance between the outer peripheral wall of the sensor bracket 610 along the radial direction R of the powertrain 20 and the axis of the motor shaft 210 is smaller than the distance between the end winding 2220 and the axis of the motor shaft 210. This results in the sensor bracket 610 having a smaller size along the radial direction R of the powertrain 20, allowing the sensor bracket 610 to be accommodated in the inner region 2221 surrounded by the end winding 2220. Consequently, the arrangement of the sensor bracket 610 can fully utilize the radial and axial space of the inner region 2221 surrounded by the end winding 2220, which is beneficial for shortening the axial dimension of the powertrain 20.

[0150] In one embodiment, as shown in FIG9, the sensor bracket 610 is also used to press the outer ring of the motor bearing 5141 along the axial direction O of the powertrain 20. The distance between the sensor bracket 610 and the axis of the motor shaft 210 along the radial direction R of the powertrain 20 is less than half the inner diameter of the motor shaft bearing groove 514.

[0151] In this embodiment, since the first housing 510 and the sensor bracket 610 occupy the space of the inner region 2221 surrounded by the end winding 2220, the space between the first housing 510 and the rotor 230 of the drive motor 200 is very small. There is no space to add an additional pressure plate to press the motor bearing 5141. Reusing the sensor bracket 610 to press the outer ring of the motor bearing 5141 is beneficial to make the integration of the powertrain 20 higher.

[0152] In this embodiment, the distance between the radial R sensor bracket 610 of the powertrain 20 and the axis of the motor shaft 210 is denoted as L1, and half the inner diameter of the motor shaft bearing groove 514 is denoted as L2. By setting L1 < L2, the sensor bracket 610 can contact the outer ring of the motor bearing 5141 in the motor shaft bearing groove 514. This allows the sensor bracket 610 used to fix the stator 621 of the resolver sensor 620 to press the outer ring of the motor bearing 5141, so that the sensor bracket 610 can play a role in reducing the axial movement of the rotor 230, thereby improving the NVH performance of the powertrain 20 and reducing the use of additional pressure plates, which is beneficial to reducing production costs.

[0153] In one embodiment, as shown in FIG9, the side of the reducer housing 500 facing the drive motor 200 is also used to fix the outer ring of a resolver sensor 620. The inner ring of a resolver sensor 620 is arranged along the axial direction O of the drive motor 200 between the bearing 5141 of the motor shaft 210 and the motor rotor 230. The motor shaft 210 is used to extend through the inner ring of a resolver sensor 620 into the interior of the reducer housing 500 to drive and connect the first-stage planetary gear set 310.

[0154] In this embodiment, the reducer housing 500 facing the drive motor 200 is also used to fix the outer ring of a resolver sensor 620. The inner ring of the resolver sensor 620 is arranged along the axial direction O of the drive motor 200 between the bearing 5141 of the motor shaft 210 and the motor rotor 230. This arrangement allows the resolver sensor 620 to make full use of the axial space between the bearing 5141 of the motor shaft 210 and the motor rotor 230. It also allows the resolver sensor 620 to be accommodated in the end winding 2220, further utilizing the space in the end winding 2220. This makes the layout of the components in the powertrain 20 more compact, which helps to reduce the axial dimension of the powertrain 20, resulting in a smaller powertrain 20 and optimizing the layout of the powertrain 20 in the vehicle.

[0155] In this embodiment, the motor shaft 210 is used to pass through the inner ring of the resolver sensor 620 and extend into the interior of the reducer housing 500 to drive the first-stage planetary gear set 310. This facilitates the resolver sensor 620 to receive the rotational speed information of the motor rotor 230 driven by the motor shaft 210. The extension of the motor shaft 210 into the interior of the reducer housing 500 also helps to improve the transmission stability between the motor shaft 210 and the first-stage planetary gear set 310.

[0156] The axial direction O of the drive motor 200 is the same as the axial direction of the powertrain 20.

[0157] In one embodiment, as shown in FIG9, the reducer housing 500 further includes a motor shaft bearing groove 514 on the side facing the drive motor 200. The motor shaft bearing groove 514 is used to fix the outer ring of the bearing 5141 of the motor shaft 210, and the inner ring of the bearing 5141 of the motor shaft 210 is used to fit around the motor shaft 210. The groove wall of the motor shaft bearing groove 514 is used to fix a sensor bracket 610, and the sensor bracket 610 is used to fix the outer ring of a resolver sensor 620 and to surround the resolver sensor 620 circumferentially. As shown in FIG9 and FIG10, the bottom of the motor shaft bearing groove 514 includes a through hole 516, through which the motor shaft 210 extends into the interior of the reducer housing 500.

[0158] In this embodiment, the groove wall of the motor shaft bearing groove 514 is used to fix a sensor bracket 610. The sensor bracket 610 is used to fix the outer ring of a resolver sensor 620 and to surround the resolver sensor 620 circumferentially. This arrangement of the sensor bracket 610 utilizes the space inside the radial R end winding 2220 of the powertrain 20 and outside the resolver sensor 620 without occupying too much axial space of the powertrain 20, which is beneficial to making the axial dimension of the powertrain 20 smaller.

[0159] In this embodiment, the sensor bracket 610 is fixed to the groove wall of the motor shaft bearing groove 514. The motor shaft bearing groove 514 is used to fix the bearing 5141 of the motor shaft 210. Thus, the sensor bracket 610 can be reused as a baffle for the bearing 5141 of the motor shaft 210, limiting the bearing 5141 of the motor shaft 210 within the motor shaft bearing groove 514, thereby reducing the axial movement of the bearing 5141 of the motor shaft 210.

[0160] In this embodiment, the bottom of the motor shaft bearing groove 514 includes a through hole 516, allowing the motor shaft 210 to pass through the bottom of the motor shaft bearing groove 514 and extend into the interior of the reducer housing 500 to drive the primary planetary gear set 310.

[0161] In one embodiment, as shown in FIG9, one end 211 of the motor shaft 210 extending into the interior of the reducer housing 500 is used as the sun gear 311 of the first-stage planetary gear set 310 to drive the planet gears 312 of the first-stage planetary gear set 310.

[0162] In this embodiment, one end 211 of the motor shaft 210 extending into the reducer housing 500 is used as the sun gear 311 of the first-stage planetary gear set 310. This makes the transmission between the motor shaft 210 and the first-stage planetary gear set 310 more direct, without the need for additional transmission components. This helps to make the transmission between the drive motor 200 and the planetary coaxial reducer 300 more stable, thereby increasing the critical speed of the drive motor 200. It also makes the arrangement between the motor shaft 210 and the first-stage planetary gear set 310 more compact, making the axial dimension of the powertrain 20 shorter, which is beneficial to the miniaturization of the powertrain 20.

[0163] In one embodiment, the motor shaft 210 is an integral shaft, which makes the powertrain 20 more integrated and also helps to improve the stability and reliability of the powertrain 20.

[0164] Figure 12 is a partial enlarged view of the M2 part of the planetary reducer 300 and the motor shaft 210 in Figure 4.

[0165] In one embodiment, as shown in Figures 4, 8, and 12, the inner peripheral wall 5114 of the groove 511 includes a first section 5115 and a second section 5116. The first section 5115 is used to fix the gear ring 313 of the planetary gear set 310, and the gear ring 313 is used to mesh with multiple planet gears 312 of the planetary gear set 310. The inner space of the second section 5116 is used to accommodate the thrust needle roller bearing 630 and part of the planet carrier 314 of the planetary gear set 310. The thrust needle roller bearing 630 is used to rotatably connect the planet carrier 314 of the planetary gear set 310 and the first housing 510. As shown in Figures 3 and 4, the first section 5115, the second section 5116, and the rotor 230 of the drive motor 200 are arranged sequentially along the axial direction O of the powertrain 20. As shown in Figure 8, the inner diameter of the second section 5116 along the radial direction R of the powertrain 20 is smaller than the inner diameter of the first section 5115.

[0166] In this embodiment, the first segment 5115 is used to fix the gear ring 313 of the planetary gear set 310. The gear ring 313 is used to mesh with the multiple planetary gears 312 of the planetary gear set 310, so that the multiple planetary gears 312 of the planetary gear set 310 can rotate normally in the first housing 510. The thrust needle roller bearing 630 is used to rotatably connect the planet carrier of the planetary gear set 310 and the first housing 510, so that the planet carrier 314 of the planetary gear set 310 can rotate in the first housing 510, which is beneficial to ensure the normal operation of the planetary reducer 300.

[0167] In this embodiment, the first segment 5115, the second segment 5116 and the rotor 230 of the drive motor 200 are arranged sequentially along the axial direction O of the powertrain 20, so that the thrust needle roller bearing 630 contained in the inner space of the second segment 5116 can be rotatably connected to the planet carrier 314 of the planetary gear set 310 and the first housing 510.

[0168] In this embodiment, the inner diameter of the second segment 5116 along the radial direction R of the powertrain 20 is smaller than the inner diameter of the first segment 5115. Because the groove 511 is recessed towards the end winding 2220, the smaller inner diameter of the second segment 5116 allows it to extend into the inner region 2221 surrounded by the end winding 2220. The first segment 5115 has a larger inner diameter, and compared to the second segment 5116, it is further away from the rotor 230 of the drive motor 200 along the axial direction O of the powertrain 20, giving the first segment 5115 more space to accommodate the planetary gear set 310.

[0169] In one embodiment, as shown in Figures 8 and 9, the inner diameter of the second segment 5116 along the radial direction R of the powertrain 20 is smaller than the inner diameter of the first segment 5115. This allows for more space for the copper busbar 240 to extend from the end winding 2220 away from the stator core 221, making the powertrain 20 structurally compact while ensuring that the arrangement of components does not interfere with each other.

[0170] In one embodiment, as shown in Figures 4, 6, and 8, the second housing 520 encloses the opening 5110 of the groove 511. The second housing 520 is recessed away from the first housing 510 along the axial direction O of the powertrain 20. The second housing 520 is used to accommodate another planetary gear set 320 of the planetary reducer 300. As shown in Figure 4, the first housing 510 also includes a planetary bearing groove 515, which accommodates a planetary carrier bearing 5151. The inner ring of the planetary carrier bearing 5151 is fixed to the inner wall of the planetary bearing groove 515, and the outer ring of the planetary carrier bearing 5151 is fixed to the planetary carrier 321 of the other planetary gear set 320. Along the axial direction O of the powertrain 20, the opening of the planetary bearing groove 515 faces the second housing 520. Along the circumferential direction C of the powertrain 20, the planetary bearing groove 515 surrounds the outer periphery of the groove 511. Along the radial direction R of the powertrain 20, the planetary bearing groove 515 overlaps with the projected portion of the first segment 5115.

[0171] In this embodiment, the second housing 520 is recessed away from the first housing 510 along the axial direction O of the powertrain 20, so that the second housing 520 has sufficient axial space to accommodate another planetary gear set 320 of the planetary reducer 300.

[0172] In this embodiment, the first housing 510 further includes a planetary bearing groove 515, which is used to accommodate a planetary carrier bearing 5151. The inner ring of the planetary carrier bearing 5151 is fixed to the inner wall of the planetary bearing groove 515, and the outer ring of the planetary carrier bearing 5151 is fixed to the planetary carrier 321 of another planetary gear set 320, so that the planetary carrier 321 can rotate through the planetary carrier bearing 5151, thereby driving the multiple planetary gears 324 in the other planetary gear set 320 to rotate.

[0173] In this embodiment, the opening of the planetary bearing groove 515 along the axial direction of the powertrain 20 faces the second housing 520, which facilitates the installation of the planetary carrier bearing 5151 from the opening direction of the planetary bearing groove 515. The planetary bearing groove 515 along the circumferential direction C of the powertrain 20 surrounds the outer periphery of the groove 511. The groove 511 is used to accommodate the planetary gear set 310 of the planetary reducer 300, so that the planetary carrier bearing 5151 can be arranged around the outer periphery of the planetary gear set 310. The projection of the planetary bearing groove 515 along the radial direction R of the powertrain 20 and the first segment 5115 can partially overlap, so that the projection of the planetary carrier bearing 5151 and the planetary gear set 310 along the radial direction R of the powertrain 20 partially overlaps. That is, the arrangement of the planetary carrier bearing 5151 can utilize part of the space of the planetary gear set 310 along the axial direction O of the powertrain 20, so that the axial arrangement of the planetary carrier bearing 5151 and the planetary gear set 310 is compact, making the axial dimension of the planetary reducer 300 smaller, which is beneficial to shortening the axial dimension of the powertrain 20.

[0174] In one embodiment, the planetary carrier bearing 5151 is a ball bearing or a needle roller bearing.

[0175] In one embodiment, as shown in FIG3, the planetary bearing groove 515 along the axial direction of the powertrain 20 is embedded in the space between the opening 401 of the motor housing 400 and the end winding 2220, and the groove 511 along the axial direction of the powertrain 20 is embedded in the space between the opening 401 of the motor housing 400 and the rotor 230 of the drive motor 200.

[0176] In this embodiment, the planetary bearing groove 515 along the circumferential direction C of the powertrain 20 surrounds the outer periphery of the groove 511, so that the planetary bearing groove 515 occupies the space of the outer periphery of the groove 511. The inner region 2221 of the groove 511 facing the end winding 2220 is recessed. The planetary bearing groove 515 is embedded in the space between the opening 401 of the motor housing 400 and the end winding 2220 along the axial direction O of the powertrain 20, which can avoid interference between the first housing 510 part corresponding to the planetary bearing groove 515 and the end winding 2220. Thus, the planetary bearing groove 515 and the end winding 2220 are arranged opposite each other along the axial direction O of the powertrain 20, so that the planetary carrier bearing 5151 and the end winding 2220 are aligned axially. This can make full use of the space between the opening 401 of the motor housing 400 and the end winding 2220 to accommodate the first section 5115 and the second section 5116 of the groove 511.

[0177] In this embodiment, the axial groove 511 of the powertrain 20 is embedded in the space between the opening 401 of the motor housing 400 and the rotor 230 of the drive motor 200. This arrangement of the first segment 5115 and the second segment 5116 of the groove 511 can make full use of the space between the opening 401 of the motor housing 400 and the rotor 230 of the drive motor 200. This is beneficial for arranging the planetary reducer 300 closer to the rotor 230 of the drive motor 200 and for giving the powertrain 20 a smaller axial dimension.

[0178] In one embodiment, as shown in FIG3, the inner diameter of the outer peripheral wall of the radial R planetary bearing groove 515 of the powertrain 20 is greater than the inner diameter of the end winding 2220, and the groove depth of the axial O planetary bearing groove 515 of the powertrain 20 is less than the distance between the opening 401 of the motor housing 400 and the end winding 2220.

[0179] In this embodiment, the inner diameter of the outer peripheral wall of the planetary bearing groove 515 along the radial direction R of the powertrain 20 is larger than the inner diameter of the end winding 2220. Along the axial direction O of the powertrain 20, the first housing 510 is recessed towards the inner region 2221 surrounding the end winding 2220 to form a groove 511. This allows the planetary bearing groove 515 to be arranged around the outer periphery of the groove 511 along the circumferential direction C of the powertrain 20, so that the planet carrier bearing 5151 in the planetary bearing groove 515 overlaps with the projection portion of the planetary gear set 310 in the groove 511 along the radial direction R of the powertrain 20. This makes the planetary reducer 300 have a smaller axial dimension, which is beneficial to reducing the axial dimension of the powertrain 20.

[0180] In this embodiment, the depth of the planetary bearing groove 515 along the axial direction O of the powertrain 20 is less than the distance between the opening 401 of the motor housing 400 and the end winding 2220, so that the planetary bearing groove 515 can be accommodated in the space between the opening 401 of the motor housing 400 and the end winding 2220 along the axial direction O of the powertrain 20, so that the arrangement of the planetary carrier bearings 5151 can utilize part of the axial space of the motor housing 400.

[0181] In one embodiment, as shown in Figures 3 and 4, the outer diameter of the gear ring 313 of the first-stage planetary gear set 310 is less than or equal to the inner diameter of the center hole 223 of the motor stator 220, and the outer diameter of the gear ring 322 of the second-stage planetary gear set 320 is greater than the inner diameter of the center hole 223 of the motor stator 220 and less than or equal to the outer diameter of the motor stator 220.

[0182] In this embodiment, the outer diameter of the ring gear 313 of the first-stage planetary gear set 310 is less than or equal to the inner diameter of the center hole 223 of the motor stator 220. The smaller outer diameter of the ring gear 313 allows the first-stage planetary gear set 310 to be arranged inside the motor housing 400, and also facilitates the insertion of a portion of the reducer housing 500 containing the first-stage planetary gear set 310 into the motor housing 400, thus reducing the axial dimension of the powertrain 20. The larger inner diameter of the center hole 223 of the motor stator 220 allows for the insertion of a portion of the reducer housing 500 into the motor housing 400, resulting in a more compact arrangement of the planetary coaxial reducer 300 and the motor stator 220, further reducing the axial dimension of the powertrain 20.

[0183] In this embodiment, because the primary planetary gear set 310 needs to be embedded within the motor housing 400, the outer diameter of the ring gear 313 of the primary planetary gear set 310 is relatively small, resulting in insufficient deceleration of the planetary coaxial reducer 300. To ensure the normal operation of the electric vehicle 1, a larger secondary planetary gear set 320 is required for deceleration. The outer diameter of the ring gear 322 of the secondary planetary gear set 320 is larger than the inner diameter of the center hole 223 of the motor stator 220, but smaller than or equal to the outer diameter of the motor stator 220. This gives the secondary planetary gear set 320 a larger outer diameter, which can further reduce the power transmitted by the primary planetary gear set 310. However, the large outer diameter of the ring gear 322 of the secondary planetary gear set 320 cannot be accommodated within the motor housing 400, thus requiring the secondary planetary gear set 320 to be positioned on the outside of the motor housing 400.

[0184] In one embodiment, as shown in Figures 3 and 4, the gear ring 313 of the first-stage planetary gear set 310 is less than or equal to the outer diameter of the outer circumferential surface around which the end winding 2220 surrounds, and the outer diameter of the gear ring 322 of the second-stage planetary gear set 320 is greater than the outer diameter of the outer circumferential surface around which the end winding 2220 surrounds, but less than or equal to the outer diameter of the motor stator 220.

[0185] In this embodiment, the gear ring 313 of the first-stage planetary gear set 310 is smaller than or equal to the outer diameter of the outer circumferential surface around the end winding 2220, thereby making the first-stage planetary gear set 310 smaller. This allows the first-stage planetary gear set 310 to be arranged inside the motor housing 400, and also allows a portion of the reducer housing 500 used to accommodate the first-stage planetary gear set 310 to extend into the inner side of the end winding 2220. This allows for the reuse of some axial space within the end winding 2220, making the arrangement of the first-stage planetary gear set 310 and the drive motor 200 more compact, thereby shortening the axial space of the powertrain 20.

[0186] In this embodiment, the outer diameter of the ring gear 322 of the secondary planetary gear set 320 is larger than the outer diameter of the outer circumferential surface around which the end winding 2220 surrounds, but smaller than or equal to the outer diameter of the motor stator 220. On the one hand, the larger outer diameter of the ring gear 322 of the secondary planetary gear set 320 allows the secondary planetary gear set 320 to have a larger outer diameter, which can further reduce the power transmitted by the primary planetary gear set 310, thereby meeting the deceleration requirements of the entire vehicle. On the other hand, the larger outer diameter of the ring gear 322 of the secondary planetary gear set 320 prevents it from being installed inside the end winding 2220 within the motor housing 400, thus requiring the secondary planetary gear set 320 to be arranged on the outside of the motor housing 400.

[0187] In one embodiment, as shown in FIG8, the inner wall of the groove 511 includes an annular protrusion 517. As shown in FIG4 and FIG6, the inner peripheral surface of the annular protrusion 517 is used to fix the gear ring 313 of the first-stage planetary gear set 310, and the outer peripheral surface of the annular protrusion 517 is used to fix a bearing 5151 of the planet carrier 321 in the second-stage planetary gear set 320.

[0188] In this embodiment, the inner circumferential surface of an annular protrusion 517 is used to fix the gear ring 313 of the first-stage planetary gear set 310, and the outer circumferential surface of the annular protrusion 517 is used to fix a bearing 5151 of the planet carrier 321 in the second-stage planetary gear set 320. This allows the bearing 5151 of the planet carrier 321 in the second-stage planetary gear set 320 to be arranged around the outer circumference of the gear ring 313 of the first-stage planetary gear set 310 along the circumferential direction C of the powertrain 20. This arrangement of the bearing 5151 of the planet carrier 321 in the second-stage planetary gear set 320 can utilize the first-stage planetary gear set 310's bearing ring 313. The space of the gear ring 313 of the gear set 310 along the radial R direction of the powertrain 20 also allows the arrangement of one bearing 5151 of the planet carrier 321 in the second-stage planetary gear set 320 to reuse the space of the gear ring 313 of the first-stage planetary gear set 310 along the axial O direction of the powertrain 20. This makes the structure of the first-stage planetary gear set 310 and the second-stage planetary gear set 320 of the planetary coaxial reducer 300 more compact and integrated, which is conducive to shortening the axial dimension of the powertrain 20, miniaturizing the powertrain 20, and optimizing the layout of the powertrain 20 in the whole vehicle.

[0189] In one embodiment, the annular protrusion 517 is used to form part of the groove wall of the planetary bearing groove 515, and the planetary bearing 5151 of the planet carrier 321 in the secondary planetary gear set 320 is the planetary carrier bearing 5151 accommodated in the planetary bearing groove 515.

[0190] In one embodiment, as shown in FIG4, one end 3142 of the planet carrier 314 in the first-stage planetary gear set 310 is used to fix the sun gear 323 of the second-stage planetary gear set 320, and the center hole 3141 of the planet carrier 314 in the first-stage planetary gear set 310 is used to accommodate another bearing 3212 of the planet carrier 321 in the second-stage planetary gear set 320.

[0191] In this embodiment, one end 3142 of the planet carrier 314 in the first-stage planetary gear set 310 is used to fix the sun gear 323 of the second-stage planetary gear set 320, so that the first-stage planetary gear set 310 can transmit power to the sun gear 323 of the second-stage planetary gear set 320 through the planet carrier 314 in the first-stage planetary gear set 310, thereby achieving further deceleration.

[0192] In this embodiment, the central hole 3141 of the planet carrier 314 in the first-stage planetary gear set 310 is used to accommodate another bearing 3212 of the planet carrier 321 in the second-stage planetary gear set 320. By arranging the other bearing 3212 of the planet carrier 321 in the second-stage planetary gear set 320 within the central hole 3141 of the planet carrier 314 in the first-stage planetary gear set 310, the axial space of the central hole 3141 of the planet carrier 314 in the first-stage planetary gear set 310 is utilized, making the arrangement of the first-stage planetary gear set 310 and the second-stage planetary gear set 320 more compact. This is beneficial for making the axial dimension of the powertrain 20 smaller and can optimize the layout of the powertrain 20 in the vehicle.

[0193] In one embodiment, as shown in Figures 3 and 4, the planet carrier 314 in the first-stage planetary gear set 310 includes a fixed protrusion 3140. The fixed protrusion 3140 is away from the protrusion of the drive motor 200. The spline on the outer peripheral surface of the fixed protrusion 3140 is used for transmission connection to the sun gear 323 of the second-stage planetary gear set 320. The inner side of the fixed protrusion 3140 has a central hole 3141 for accommodating another bearing 3212 of the planet carrier 321 in the second-stage planetary gear set 320.

[0194] In this embodiment, the planet carrier 314 in the first-stage planetary gear set 310 includes a fixed protrusion 3140, which is away from the protrusion of the drive motor 200. This allows the planet carrier 314 in the first-stage planetary gear set 310 to be used to fix the sun gear 323 of the second-stage planetary gear set 320. This allows the first-stage planetary gear set 310 and the second-stage planetary gear set 320 to be arranged along the axial direction O of the powertrain 20 with a compact structure, which is beneficial for making the axial dimension of the powertrain 20 smaller.

[0195] In this embodiment, the spline on the outer peripheral surface of the fixed protrusion 3140 is used to drive the sun gear 323 of the secondary planetary gear set 320. This allows the projection of the sun gear 323 of the secondary planetary gear set 320 onto the fixed protrusion 3140 of the planet carrier 314 in the primary planetary gear set 310 along the radial R direction of the powertrain 20, resulting in a compact structural arrangement of the primary planetary gear set 310 and the secondary planetary gear set 320. Furthermore, the fixed protrusion 3140 has a central hole 3141 on its inner side to accommodate another bearing 3212 of the planet carrier 321 in the secondary planetary gear set 320. This eliminates the need for the other bearing 3212 of the planet carrier 321 in the secondary planetary gear set 320 to occupy additional axial space of the sun gear 323, thus reducing the axial dimension of the powertrain 20 and optimizing its layout within the vehicle.

[0196] Figure 13 is a schematic diagram of a first-stage planetary gear set 310 provided in an embodiment of this application, and Figure 14 is a schematic diagram of a second-stage planetary gear set 320 provided in an embodiment of this application.

[0197] In one embodiment, as shown in FIG13, the planet carrier 314 of the first-stage planetary gear set 310 includes two end plates 3146 and 3147, which are arranged opposite each other along the axial direction O of the powertrain 20. The space between the two end plates 3146 and 3147 is used to accommodate the planet gears 312 of the first-stage planetary gear set 310. One end plate 3146 includes a through hole 3148. As shown in FIG4 and FIG13, one end 211 of the motor shaft 210 passes through the through hole 3148 and extends between the two end plates 3146 and 3147. Multiple teeth 214 of the motor shaft 210 are located between the two end plates 3146 and 3147. The other end plate 3147 includes a fixing protrusion 3140. Along the axial direction O of the powertrain 20, the fixing protrusion 3140 is opposite to the protrusion of the motor shaft 210. The fixing protrusion 3140 is used to fit and drive the sun gear 323 in the second-stage planetary gear set 320. The two end plates 3146 and 3147 have multiple holes (not shown) for passing through the planet shaft 315 of the first-stage planetary gear set 310, and the multiple holes are distributed around the through hole 3148.

[0198] In this embodiment, by integrally forming a fixed protrusion 3140 on the planet carrier 314 of the first-stage planetary gear set 310 to accommodate and fix the sun gear 323 of the second-stage planetary gear set 320, the structures of the first-stage planetary gear set 310 and the second-stage planetary gear set 320 are made more compact. This helps to shorten the axial dimension of the planetary coaxial reducer 300, and consequently, the axial dimension of the powertrain 20. It also simplifies the transmission structure of the first-stage planetary gear set 310 and the second-stage planetary gear set 320, thus improving transmission stability.

[0199] In one embodiment, as shown in FIG14, the planet carrier 321 of the secondary planetary gear set 320 includes two end plates 3224 and 3225. The two end plates 3224 and 3225 are arranged opposite to each other along the axial direction O of the powertrain 20. The two end plates 3224 and 3225 are connected by multiple connecting plates. The space between the two end plates 3224 and 3225 is used to accommodate the planet gears 324 of the secondary planetary gear set 320. One end plate 3224 includes a through hole 3226. As shown in FIG4 and FIG14, the fixing protrusion 3140 of the planet carrier 314 of the primary planetary gear set 310 extends through the through hole 3226 and into the space between the two end plates 3224 and 3225. One of the end plates 3224 also includes a fixing protrusion 3227, which protrudes toward the motor shaft 210 along the axial direction of the powertrain 20. The fixing protrusion 3227 is used to mount and drive a bearing 5151 of the planet carrier 321 in the secondary planetary gear set 320.

[0200] In this embodiment, the fixed protrusion 3140 of the planet carrier 314 of the first-stage planetary gear set 310 extends through the through hole 3226 and between the two end plates 3224 and 3225, making the structure of the planet carrier 314 of the first-stage planetary gear set 310 and the planet carrier 321 of the second-stage planetary gear set 320 compact, which is beneficial to make the planetary coaxial reducer 300 have a smaller axial dimension.

[0201] In this embodiment, an end plate 3224 further includes a fixing protrusion 3227. The fixing protrusion 3227 protrudes towards the motor shaft 210 along the axial direction of the powertrain 20. The fixing protrusion 3227 is used to mount and drive a bearing 5151 of the planet carrier 321 in the secondary planetary gear set 320, so that the planet carrier 321 of the secondary planetary gear set 320 can be drive-connected to a bearing 5151 of the planet carrier 321 in the secondary planetary gear set 320 fixed to the outer circumferential surface of an annular protrusion 517. The annular protrusion 517 is used to fix the inner ring of the bearing 5151, and the fixing protrusion 3227 is used to fix the outer ring of the bearing 5151.

[0202] In one embodiment, as shown in Figures 5 to 8, the first housing 510 of the reducer housing 500 is recessed in a groove 511 formed on the side of the first housing 510 away from the drive motor 200 along the direction toward the drive motor 200, which is referred to as the first groove 511.

[0203] In one embodiment, as shown in Figures 6 to 8, the first housing 510 includes two mounting surfaces 518 and 519, which are opposite to each other along the axial direction O of the drive motor 200. One mounting surface 518 is used to mate with the mounting surface 440 of the motor housing 400, and the other mounting surface 519 is used to mate with the mounting surface 521 of the second housing 520. A first groove 511 is recessed from the inner side of the other mounting surface 519 toward the drive motor 200 along the axial direction O of the powertrain 20.

[0204] In this embodiment of the application, the first housing 510 includes two mounting surfaces 518 and 519, which are opposite to each other along the axial direction O of the drive motor 200, so that the first housing 510 can be fixedly installed with the mounting surface 440 of the motor housing 400 and the mounting surface 521 of the second housing 520, respectively.

[0205] In this embodiment, the first groove 511 along the axial direction O of the powertrain 20 is recessed from the inner side of the other mounting surface 519 toward the drive motor 200, so that the first housing 510 can utilize the axial space inside the motor housing 400, making the axial space outside the motor housing 400 occupied by the first housing 510 smaller. This is beneficial to making the overall axial dimension of the planetary coaxial reducer 300 and the drive motor 200 smaller, and to shortening the axial length of the powertrain 20.

[0206] In one embodiment, as shown in Figures 6 to 8, the two mounting surfaces 518 and 519 of the first housing 510, the mounting surface 440 of the motor housing 400, and the mounting surface 521 of the second housing 520 are planar surfaces. In another embodiment, the two mounting surfaces 518 and 519 of the first housing 510, the mounting surface 440 of the motor housing 400, and the mounting surface 521 of the second housing 520 are curved surfaces with concave and convex fits. It is sufficient that one mounting surface 518 can cooperate and seal with the mounting surface 440 of the motor housing 400, and the other mounting surface 519 can cooperate and seal with the mounting surface 521 of the second housing 520.

[0207] In one embodiment, as shown in Figures 3 and 6, the second housing 520 is recessed in the direction away from the drive motor 200 to form a second groove 522 on the side of the second housing 520 facing the drive motor 200. The inner wall of the second groove 522 is used to fix the gear ring 322 of the secondary planetary gear set 320.

[0208] In this embodiment, the second housing 520 is recessed along the direction away from the drive motor 200, forming a second groove 522 on the side of the second housing 520 facing the drive motor 200. This provides sufficient space in the second housing 520 along the axial direction O of the powertrain 20 to accommodate the secondary planetary gear set 320. The inner wall of the second groove 522 is used to fix the gear ring 322 of the secondary planetary gear set 320, allowing the planet gears in the secondary planetary gear set 320 to engage with the gear ring 322 fixed to the inner wall of the second groove 522. This allows the secondary planetary gear set 320 to rotate within the second housing 520 without interference from the second housing 520.

[0209] In this embodiment, the gear ring 322 of the secondary planetary gear set 320 is fixed inside the second housing 520, so that when the mounting surface 521 of the second housing 520 is installed with the other mounting surface 519 of the first housing 510, the gear ring 322 of the secondary planetary gear set 320 can be directly assembled with the planet gears 324 in the secondary planetary gear set 320, simplifying the assembly process.

[0210] In one embodiment, as shown in Figures 2 and 4, the second housing 520 includes a shaft hole 523, which connects the interior and exterior of the reducer housing 500 along the axial direction O of the drive motor 200. The shaft hole 523 is used to accommodate one end of the planet carrier 321 in the secondary planetary gear set 320. One end of the planet carrier 321 in the secondary planetary gear set 320 includes an internal spline, which is used to drive the half-shaft 50 of the electric vehicle 1. The half-shaft 50 of the electric vehicle 1 is used to drive the wheel 40 of the electric vehicle 1.

[0211] In this embodiment, the shaft hole 523 is used to accommodate one end of the planet carrier 321 in the secondary planetary gear set 320. One end of the planet carrier 321 in the secondary planetary gear set 320 includes an internal spline, so that the half shaft 50 of the electric vehicle 1 can be directly connected to the planet carrier 321 in the secondary planetary gear set 320 after it extends into the inner side of one end of the planet carrier 321 in the secondary planetary gear set 320. This eliminates the need for additional adapters for the transmission between the secondary planetary gear set 320 and the half shaft 50 of the electric vehicle 1, thereby reducing the space reserved for the transmission connection between the powertrain 20 and the half shaft 50 of the electric vehicle 1 when assembling the powertrain 20 in the vehicle, and optimizing the layout of the powertrain 20 in the vehicle.

[0212] In this embodiment, the planet carrier 321 in the secondary planetary gear set 320 is directly connected to the half-shaft 50 of the electric vehicle, which is beneficial to reduce the radial and axial movement of the half-shaft 50 of the electric vehicle 1 during transmission and to improve the NVH performance of the whole vehicle.

[0213] In one embodiment, as shown in FIG4, the planet carrier 321 of the secondary planetary gear set 320 includes a half-shaft protrusion 3210. The half-shaft protrusion 3210 protrudes away from the primary planetary gear set 310 along the axial direction O of the powertrain 20. The half-shaft protrusion 3210 is used to pass through the shaft hole 523 and has an internal spline.

[0214] In this embodiment of the application, as shown in Figures 2 and 4, the planet carrier 321 of the secondary planetary gear set 320 includes a half-shaft protrusion 3210. The half-shaft protrusion 3210 protrudes away from the primary planetary gear set 310 along the axial direction O of the powertrain 20, so that there is space in one end of the planet carrier 321 in the secondary planetary gear set 320 to arrange an internal spline, allowing the half-shaft 50 of the electric vehicle 1 to extend into one end of the planet carrier 321 in the secondary planetary gear set 320 and be connected to the internal spline for transmission. The fact that the half-shaft protrusion 3210 protrudes away from the primary planetary gear set 310 along the axial direction O of the powertrain 20 also facilitates the half-shaft protrusion 3210 to pass through the shaft hole 523 of the second housing 520, allowing the internal spline of the half-shaft protrusion 3210 to be more smoothly connected to the half-shaft 50 of the electric vehicle 1 for transmission.

[0215] In one embodiment, an oil seal 330 is arranged between the second housing 520 and the half-shaft protrusion 3210 to seal the gap between the second housing 520 and the half-shaft protrusion 3210, thereby preventing oil leakage.

[0216] Figure 16 is a schematic diagram of a motor shaft 210 provided in an embodiment of this application.

[0217] In one embodiment, as shown in Figures 3 and 4, the reducer housing 500 includes a through hole 516 for connecting the inner cavity of the reducer housing 500 and the inner cavity of the motor housing 400. One end 211 of the motor shaft 210 along the axial direction of the powertrain 20 extends into the inner cavity of the reducer housing 500 through the through hole 516, as shown in Figures 4 and 16. One end 211 of the motor shaft 210 serves as the sun gear 311 of a planetary gear set 310.

[0218] In this embodiment of the application, the reducer housing 500 includes a through hole 516, which is used to connect the inner cavity of the reducer housing 500 and the inner cavity of the motor housing 400, so that the motor shaft 210 can pass through the through hole 516 and be arranged in both the inner cavity of the motor housing 400 and the inner cavity of the reducer housing 500.

[0219] In this embodiment, one end 211 of the motor shaft 210 along the axial direction O of the powertrain 20 extends into the inner cavity of the reducer housing 500 through the through hole 516. One end 211 of the motor shaft 210 is used as the sun gear 311 of a planetary gear set 310, so that the rotor 230 of the drive motor 200 can directly transmit power to the planet gears 312 of a planetary gear set 310 of the planetary reducer 300 through one end 211 of the motor shaft 210. This makes the integration between the drive motor 200 and the planetary reducer 300 higher, and makes the transmission process between the drive motor 200 and the planetary reducer 300 more stable, which is beneficial to improving the reliability of the powertrain 20. Compared to a planetary gear set 310 where the sun gear 311 is connected to the motor shaft 210 via a spline, using one end 211 of the motor shaft 210 as the sun gear 311 of a planetary gear set 310 to directly receive power from the rotor 230 of the drive motor 200 allows the motor shaft 210 of the drive motor 200 and the input shaft of the planetary reducer 300 to be integrated into one unit. This is beneficial for improving the bending resistance of the motor shaft 210, thereby increasing the critical speed of the rotor 230 of the drive motor 200.

[0220] In one embodiment, as shown in Figures 4 and 5, the first housing 510 includes a through hole 516 that extends through the first housing 510 along the axial direction O of the motor shaft 210. The through hole 516 is used to pass through one end 211 of the motor shaft 210. The end 211 of the motor shaft 210 passing through the through hole 516 extends into the groove 511 and serves as a sun gear 311 meshing with a plurality of planet gears 312 of the planet gear set 310.

[0221] In this embodiment, the through hole 516 penetrates the first housing 510 along the axial direction O of the motor shaft 210, so that one end 211 of the motor shaft 210 can penetrate the first housing 510 through the through hole 516.

[0222] In this embodiment, because the first housing 510 is recessed towards the end winding 2220, the planetary reducer 300 is closer to the rotor 230 of the drive motor 200. By using one end 211 of the integrated motor shaft 210 as the sun gear 311, the axial length of the sun gear 311 and the motor shaft 210 portion can be shortened. This helps to reduce the axial dimension of the powertrain 20, thereby shortening the path of the power output from the rotor 230 of the drive motor 200 to the planetary gear set of the planetary reducer 300, making the power transmission more stable and improving the critical speed of the drive motor. In this embodiment, the sun gear 311 and the motor shaft 210 are an integrated structure, and one end 211 of the motor shaft 210 with the sun gear 311 extends into the inside of the groove 511, which can be directly connected to the multiple planet gears 312 of the planetary gear set 310 in the groove 511 without additionally occupying the axial dimension of the first housing 510, which helps to further shorten the axial dimension of the powertrain 20.

[0223] The axial direction O of the motor shaft 210 is the same as the axial direction O of the powertrain 20.

[0224] In one embodiment, as shown in FIG3, along the axial direction O of the powertrain 20, the distance between the sun gear 311 and the rotor 230 of the drive motor 200 is less than the distance between the opening 401 of the motor housing 400 and the rotor 230 of the drive motor 200.

[0225] In this embodiment, along the axial direction O of the powertrain 20, the distance between the sun gear 311 and the rotor 230 of the drive motor 200 is smaller than the distance between the opening 401 of the motor housing 400 and the rotor 230 of the drive motor 200. This allows the arrangement of the sun gear 311 in the planetary reducer 300 to utilize part of the axial space of the motor housing 400, which helps to shorten the axial dimension of the powertrain 20. It also makes it easier for the sun gear 311 to directly connect with the multiple planet gears 312 of the planetary gear set 310 arranged in the groove 511 between the opening 401 of the motor housing 400 and the rotor 230 of the drive motor 200, making the transmission process more stable.

[0226] In one embodiment, as shown in Figures 4 and 16, the outer peripheral surface of one end 211 of the motor shaft 210 includes a plurality of teeth 214, which are used to mesh with and drive the planet gears 312 of a planetary gear set 310.

[0227] In this embodiment, the outer circumferential surface of one end 211 of the motor shaft 210 includes multiple teeth 214, allowing one end 211 of the motor shaft 210 to form a sun gear 311 of a planetary gear set 310. The multiple teeth 214 mesh and drive the planet gears 312 of the planetary gear set 310, thus enabling direct transmission connection between one end 211 of the motor shaft 210 and the planetary reducer 300. This eliminates the need for additional splines in the transmission between the drive motor 200 and the planetary reducer 300, allowing the planetary reducer 300 to receive power more directly from the motor shaft 210. This improves the stability of the transmission process and helps to increase the critical speed of the rotor 230. Using one end 211 of the motor shaft 210 to form the sun gear 311 also increases the integration of the transmission structure between the drive motor 200 and the planetary reducer 300, further enhancing the stability of the powertrain 20.

[0228] Figure 17 is a cross-sectional view of the motor shaft 210 and the oil guide pipe 700 provided in an embodiment of this application.

[0229] In one embodiment, as shown in Figures 4 and 17, the outer diameter of the sun gear 311 of the motor shaft 210 is smaller than the outer diameter of the portion of the motor shaft 210 used to fix the rotor 230.

[0230] In this embodiment, the rotor 230 of the drive motor 200 is relatively heavy. The outer diameter of the motor shaft 210 that fixes the rotor 230 is set to be relatively large, which is beneficial for the motor bearing 5141 to support the rotor 230 with a large load capacity. The planet gears 312 of a planetary gear set 310 are relatively light. The outer diameter of the sun gear 311 of the motor shaft 210 is set to be relatively small, which can also support the planet gears 312 of a planetary gear set 310. This makes the overall load-bearing force of the motor shaft 210 more balanced and stable.

[0231] In this embodiment, the outer diameter of the sun gear 311 of the motor shaft 210 is relatively small, which facilitates one end 211 of the motor shaft 210 containing the sun gear 311 to extend into the inner cavity of the reducer housing 500 through the through hole 516. Since the outer diameter of the sun gear 311 of the motor shaft 210 is smaller than the outer diameter of the portion of the motor shaft 210 used to fix the rotor 230, the portion of the motor shaft 210 used to fix the rotor 230 cannot pass through the through hole 516 of the reducer housing 500. This allows the reducer housing 500 to axially limit the motor shaft 210, which helps reduce axial movement of the motor shaft 210, making the transmission of the motor shaft 210 more stable and improving the critical speed of the motor rotor 230.

[0232] In this embodiment of the application, as shown in Figures 3 and 4, the outer diameter of the sun gear 311 of the motor shaft 210 is relatively small, and the planetary gear set 310 of the planetary reducer 300 is also relatively small. This makes it easier to arrange the planetary gear set 310 close to the rotor 230 of the drive motor 200 inside the motor housing 400, thereby making full use of the space of the motor housing 400, resulting in a smaller axial dimension of the powertrain 20, which is beneficial to the miniaturization of the powertrain 20.

[0233] In one embodiment, as shown in Figures 4, 5, and 9, the reducer housing 500 further includes a motor shaft bearing groove 514. The motor shaft bearing groove 514 is used to accommodate the bearing 5141 of the motor shaft 210. The groove opening 5142 of the motor shaft bearing groove 514 faces the rotor 230 along the axial direction O of the powertrain 20. The end winding 2220 of the stator 220 is located in the inner cavity of the motor housing 400. The end winding 2220 surrounds the outer periphery of the motor shaft bearing groove 514. The through hole 516 penetrates the bottom of the groove of the motor shaft bearing groove 514 along the axial direction O of the powertrain 20. One end 211 of the motor shaft 210 extends into the inner cavity of the reducer housing 500 through the through hole 516 from the motor shaft bearing groove 514.

[0234] In this embodiment, the through hole 516 extends through the bottom of the motor shaft bearing groove 514 along the axial direction O of the powertrain 20. One end 211 of the motor shaft 210 extends into the inner cavity of the reducer housing 500 through the through hole 516 from the motor shaft bearing groove 514. The motor shaft 210 extends into the reducer housing 500 from the bottom of the motor shaft bearing groove 514 located inside the end winding 2220. This allows the bearing 5141 supporting the integrated motor shaft 210 to be close to the rotor 230, which helps to shorten the axial dimension of the motor shaft 210. This makes the power transmission between the rotor 230 and the sun gear 311 of a planetary gear set 310 more stable and helps to increase the critical speed of the rotor 230.

[0235] In one embodiment, as shown in FIG4, the distance between the end of one end 211 of the motor shaft 210 and the bearing 5141 is smaller than the distance between the end of the other end 212 of the motor shaft 210 and the bearing 5141.

[0236] In this embodiment, as shown in Figures 3 and 4, the distance between the end of one end 211 of the motor shaft 210 and the bearing 5141 is denoted as L3, and the distance between the end of the other end 212 of the motor shaft 210 and the bearing 5141 is denoted as L4. L3 < L4. A smaller L3 results in a smaller distance between the sun gear 311 of a planetary gear set 310 and the bearing 5141, which is beneficial for the motor shaft 210 to more stably transmit the power of the rotor 230 of the drive motor 200 to the sun gear 311 of the planetary gear set 310, thereby helping to increase the critical speed of the rotor 230. A smaller L3 also helps to shorten the length of the motor shaft 210, increasing the rigidity of the motor shaft 210, which is also beneficial to increasing the critical speed of the rotor 230. A larger L4 provides sufficient space for the motor shaft 210 to fix the rotor 230, making the power output of the rotor 230 more stable, which is beneficial to increasing the critical speed.

[0237] In one embodiment, as shown in Figures 4 and 9, the groove wall of the motor shaft bearing groove 514 is used to fix the bearing pressure plate 610. Along the axial direction of the powertrain 20, the bearing pressure plate 610 is located between the reducer housing 500 and the rotor 230. The end winding 2220 of the stator 220 surrounds the outer periphery of the bearing pressure plate 610. The bearing pressure plate 610 is used to press the outer ring of the bearing 5141. The bearing pressure plate 610 is spaced apart from the inner ring of the bearing 5141.

[0238] In this embodiment, the groove wall of the motor shaft bearing groove 514 is used to fix the bearing pressure plate 610. The end winding 2220 surrounds the outer periphery of the motor shaft bearing groove 514. Along the axial direction O of the powertrain 20, the bearing pressure plate 610 is located between the reducer housing 500 and the rotor 230. The end winding 2220 of the stator 220 surrounds the outer periphery of the bearing pressure plate 610, so that the arrangement of the bearing pressure plate 610 will not occupy additional space outside the axial direction O of the end winding 2220 of the powertrain 20, so that the space inside the end winding 2220 is further fully utilized, which is beneficial to shortening the axial dimension of the powertrain 20.

[0239] In this embodiment, the bearing pressure plate 610 is used to press the outer ring of the bearing 5141. The bearing pressure plate 610 is spaced from the inner ring of the bearing 5141, so that the bearing pressure plate 610 and the reducer housing 500 can axially limit the bearing 5141, thereby reducing the axial movement of the bearing 5141 and improving the contact stiffness of the bearing 5141. This, in turn, improves the stability between the motor shaft 210 and the reducer housing 500, enhances the stability of power transmission, and helps to increase the critical speed of the rotor 230.

[0240] In one embodiment, the bearing plate 610 can also be used to fix the resolver sensor 620. The bearing plate 610 is also called the sensor bracket 610.

[0241] In one embodiment, as shown in FIG9, the bearing pressure plate 610 is spaced from the inner ring of the bearing 5141, thereby allowing the stator 621 of the resolver sensor 620 to be arranged in the spaced gap, making full use of the inner space of the end winding 2220.

[0242] In one embodiment, as shown in FIG9, a groove 511 is formed in the inner cavity of a portion of the reducer housing 500 facing the motor housing 400 on the side of the portion of the reducer housing 500 away from the drive motor 200. The groove 511 is used to accommodate the planet gears 312 and the sun gear 311 of a planetary gear set 310.

[0243] In this embodiment, a groove 511 is formed on the side of the reducer housing 500 facing away from the drive motor 200, with the inner cavity of the reducer housing 500 recessed towards the motor housing 400. This groove 511 can be arranged inside the motor housing 400, accommodating the planetary gears 312 and sun gear 311 of a planetary gear set 310. This allows the arrangement of the planetary gears 312 and sun gear 311 of the planetary gear set 310 to fully utilize the axial space of the inner cavity of the motor housing 400. This facilitates bringing the planetary gears 312 and sun gear 311 of the planetary gear set 310 closer to the rotor 230, shortening the axial dimension of the motor shaft 210, making the transmission of the motor shaft 210 more stable, and improving the critical speed of the rotor 230.

[0244] In one embodiment, as shown in Figures 9 and 13, a planetary gear set 310 includes a plurality of planetary gears 312 for meshing with a sun gear 311. The plurality of planetary gears 312 are evenly distributed along the circumferential direction C of the motor shaft 210 on the periphery of one end 211 of the motor shaft 210.

[0245] In this embodiment, multiple planetary gears 312 mesh with the sun gear 311. These planetary gears 312 are evenly distributed along the circumferential direction C of the motor shaft 210 on the periphery of one end 211 of the motor shaft 210. This ensures uniform radial contact stiffness of the motor shaft 210, resulting in uniform force distribution on the sun gear 311. It also helps to ensure uniform force distribution on the bearing 5141 of the motor shaft 210, improving the bending resistance of the motor shaft 210 and consequently increasing the critical speed of the rotor 230.

[0246] The circumferential direction C of the motor shaft 210 is the same as the circumferential direction C of the powertrain 20.

[0247] In one embodiment, a planetary gear set 310 includes a plurality of planetary gears 312 comprising four planetary gears 312.

[0248] In one embodiment, as shown in Figures 9, 16 and 17, the motor shaft 210 includes a motor shaft oil hole 215, which is used to connect to the internal oil passage 216 of the motor shaft 210 to receive oil. The motor shaft oil hole 215 is distributed on the outer peripheral surface of the motor shaft 210 and is exposed in the inner cavity of the reducer housing 500.

[0249] In this embodiment, the motor shaft oil hole 215 is used to connect to the internal oil passage 216 of the motor shaft 210 to receive oil. The motor shaft oil hole 215 is distributed on the outer peripheral surface of the motor shaft 210 and exposed to the inner cavity of the reducer housing 500. This allows the motor shaft oil hole 215 to spray the oil in the internal oil passage 216 of the motor shaft 210 into the inner cavity of the reducer housing 500, thereby providing lubrication for the planetary gears 312 of a planetary gear set 310 and one end of the motor shaft 210 used as the sun gear 311, which helps to ensure the normal operation of the planetary reducer 300.

[0250] In one embodiment, as shown in FIG9, the motor shaft oil hole 215 along the axial direction of the powertrain 20 is located between the sun gear 311 and the bearing 5141 of the motor shaft 210. This allows the oil sprayed from the motor shaft oil hole 215 to lubricate not only the sun gear 311 of the planetary gear set 310, but also the bearing 5141 of the motor shaft 210, thereby improving the lubrication efficiency of the powertrain 20.

[0251] In one embodiment, as shown in Figures 4 and 12, the planetary shaft 315 of a planetary gear set 310 includes an axial hole 3151 and a radial hole 3152. The axial hole 3151 is distributed on the axial end face of the planetary shaft 315 of the planetary gear set 310, and the radial hole 3152 is distributed on the outer peripheral surface of the planetary shaft 315 of the planetary gear set 310. The axial hole 3151 is used to receive oil output from the motor shaft oil hole 215, and the radial hole 3152 is used to connect the axial hole 3151 to deliver oil to the bearing 316 between the planetary shaft 315 and the planetary gear 312 of the planetary gear set 310 for lubrication.

[0252] In this embodiment, axial holes 3151 are distributed on the axial end face of the planetary shaft 315 of a planetary gear set 310, facilitating the intake of oil from the motor shaft oil hole 215 into the planetary shaft 315 of the planetary gear set 310. Radial holes 3152 are distributed on the outer circumferential surface of the planetary shaft 315 of the planetary gear set 310, facilitating the delivery of oil to the bearing 316 between the planetary shaft 315 and the planetary gears 312 of the planetary gear set 310 for lubrication.

[0253] In this embodiment, the axial hole 3151 is used to receive the oil output from the motor shaft oil hole 215, and the radial hole 3152 is used to connect the axial hole 3151 to deliver oil to the bearing 316 between the planetary shaft 315 and the planetary gear 312 of a planetary gear set 310 for lubrication. This allows the oil output from the motor shaft oil hole 215 to flow sequentially through the axial hole 3151 and the radial hole 3152 to the bearing 316 between the planetary shaft 315 and the planetary gear 312 of a planetary gear set 310 and lubricate it, thereby ensuring the normal operation of the planetary gear 312 of the planetary gear set 310.

[0254] In one embodiment, as shown in FIG12, the opening of the axial bore 3151 of the planetary shaft 315 of a planetary gear set 310 faces the bottom 5111 of the groove 511. This facilitates the input of oil into the axial bore 3151 of the planetary shaft 315 of the planetary gear set 310 along the axial direction O of the powertrain 20, located between the sun gear and the bottom 5111 of the groove 511, thereby lubricating the bearing 316 between the planetary shaft 315 and the planetary gears 312 of the planetary gear set 310.

[0255] In one embodiment, as shown in Figures 4, 6, and 12, the groove 511 is also used to accommodate the thrust needle roller bearing 630 and the oil collecting baffle 640. The thrust needle roller bearing 630 is used to rotatably connect the planet carrier 314 of the first-stage planetary gear set 310 and the first housing 510. Along the axial direction of the powertrain 20, the thrust needle roller bearing 630 is arranged between the planetary shaft 315 of the first-stage planetary gear set 310 and the bottom 5111 of the groove 511. The opening of the axial hole 3151 of the planetary shaft 315 in the first-stage planetary gear set 310 is exposed to the thrust needle roller bearing 630. The thrust needle roller bearing 630 surrounds the outer periphery of the motor shaft oil hole 215. The gap in the thrust needle roller bearing 630 is used to transmit the oil output from the motor shaft oil hole 215 to the opening of the planetary shaft 315 of the first-stage planetary gear set 310. The oil collecting baffle 640 surrounds the outer periphery of the thrust needle roller bearing 630. The oil collecting baffle 640 is used to cover the outer peripheral surface of the thrust needle roller bearing 630 and the opening of the axial hole 3151 of the planetary shaft 315 in the first-stage planetary gear set 310, and to connect the gap between the outer peripheral surface of the thrust needle roller bearing 630 and the opening of the axial hole 3151 of the planetary shaft 315 in the first-stage planetary gear set 310.

[0256] In this embodiment, the clearance in the thrust needle roller bearing 630 is used to transmit the oil output from the motor shaft oil hole 215 to the axial hole 3151 opening of the planetary shaft 315 of the first-stage planetary gear set 310. This allows the oil collecting baffle 640 to guide the oil thrown out of the motor shaft oil hole 215 into the axial hole 3151 opening of the planetary shaft 315 of the first-stage planetary gear set 310, thereby lubricating the planetary gears 312 of the first-stage planetary gear set 310. The oil collecting baffle 640 covers the outer circumferential surface of the thrust needle roller bearing 630, preventing the oil thrown onto the thrust needle roller bearing 630 from being directly thrown onto the groove wall of the groove 511, thus avoiding oil leakage. This allows the thrust needle roller bearing 630 and the first-stage planetary gear set 310 to receive more concentrated oil lubrication, which is beneficial for ensuring the normal operation of the planetary coaxial reducer 300.

[0257] In one embodiment, as shown in FIG12, the oil collecting baffle 640 is annular and includes a first opening 641 and a second opening 642. The first opening 641 is used to connect with the second opening 642. The first opening 641 is directed toward the thrust needle roller bearing 630 along the radial direction R of the powertrain 20. The first opening 641 is used to receive the oil output from the motor shaft oil hole 215 through the gap in the thrust needle roller bearing 630. The second opening 642 is directed toward the axial hole 3151 of the planetary shaft 315 in the first-stage planetary gear set 310 along the axial direction O of the powertrain 20. The second opening 642 is used to transport the oil to the axial hole 3151 of the planetary shaft 315 in the first-stage planetary gear set 310.

[0258] In this embodiment, the first opening 641 faces the thrust needle roller bearing 630 along the radial direction R of the powertrain 20. The first opening 641 is used to receive oil output from the motor shaft oil hole 215 through the gap in the thrust needle roller bearing 630, thereby allowing the first opening 641 to receive oil thrown out from the motor shaft oil hole 215. The second opening 642 faces the axial hole 3151 in the planetary shaft 315 of the first-stage planetary gear set 310 along the axial direction O of the powertrain 20. The second opening 642 is used to transport oil to the axial hole 3151 in the planetary shaft 315 of the first-stage planetary gear set 310, thereby allowing the oil collected by the first opening 641 of the oil collecting baffle 640 to be introduced into the axial hole 3151 in the planetary shaft 315 of the first-stage planetary gear set 310 through the second opening 642, thereby lubricating the planetary gears 312 in the first-stage planetary gear set 310 and enabling the planetary coaxial reducer 300 to operate normally.

[0259] In one embodiment, as shown in Figures 4 and 13, the planetary reducer 300 further includes another planetary gear set 320. The planetary shaft 3230 of the other planetary gear set 320 includes a communicating axial bore 3231 and a radial bore 3232. The radial bore 3232 is used to output the oil received by the axial bore 3231 to the bearing of the planetary shaft 3230 for lubrication. The planet carrier 314 of one planetary gear set 310 is spaced from the inner wall of the reducer housing 500. The space between the planet carrier 314 of one planetary gear set 310 and the inner wall of the reducer housing 500 is used to transmit the oil output from the radial bore 3152 of the planet carrier 314 of one planetary gear set 310 to the axial bore 3231 of the planetary shaft 3230 of the other planetary gear set 320. This allows oil to flow from one planetary gear set 310 into another planetary gear set 320, enabling oil to flow and lubricate in the two-stage planetary gear sets. This reduces the oil circuit structure of the reducer housing 500 and simplifies the oil circuit design of the powertrain 20.

[0260] In one embodiment, the groove wall of the groove 511 is used to fix the gear ring 313 of a planetary gear set 310. The planet carrier 314 of the planetary gear set 310 is spaced from the groove wall of the groove 511. The gap between the planet carrier 314 of the planetary gear set 310 and the groove wall of the groove 511 is used to transfer the oil output from the radial hole 3152 of the planet carrier 314 of the planetary gear set 310 to the axial hole 3231 of the planet shaft 3230 of the other planetary gear set 310. By separating the planet carrier 314 of the planetary gear set 310 from the groove wall of the groove 511, the oil lubricating the planetary gear set 310 can flow from the gap between the planet carrier 314 of the planetary gear set 310 and the groove wall of the groove 511 into the other planetary gear set 320 for lubrication, thus achieving oil reuse.

[0261] In one embodiment, the inner diameter of the ring gear 322 of another planetary gear set 320 is larger than the inner diameter of the ring gear 313 of a planetary gear set 310, and the opening of the axial bore 3231 of the planetary shaft 3230 of the other planetary gear set 320 faces the gap between the planet carrier 314 of the planetary gear set 310 and the groove wall of the groove 511. When the planet carrier 314 and planet gears 312 of a planetary gear set 310 rotate, they throw oil out circumferentially. By making the inner diameter of the ring gear 322 of the other planetary gear set 320 larger than the inner diameter of the ring gear 313 of the planetary gear set 310, the axial bore 3151 of the planetary shaft 315 of the planetary gear set 310 is distributed on the outer periphery of the planet carrier 314 of the planetary gear set 310, which facilitates the reception of the oil thrown out by the planetary gear set 310.

[0262] In one embodiment, the planet carrier 314 of one planetary gear set 310 includes an end plate 3146, and the opening of the axial bore 3231 of the planet shaft 3230 of another planetary gear set 320 faces the gap between the end plate 3146 and the groove wall of the groove 511. The outer diameter of the end plate 3146 is smaller than the groove width of the groove 511 along the radial direction R of the powertrain 20, such that oil flowing from the radial bore 3152 of the planet shaft 315 of one planetary gear set 310 can be thrown from the gap between the end plate 3146 and the groove wall of the groove 511 into the axial bore 3231 of the planet shaft 3230 of the other planetary gear set 320.

[0263] In one embodiment, as shown in Figures 4 and 13, the planetary reducer 300 further includes another planetary gear set 320. The outer peripheral surface of one end 3142 of the planet carrier 314 of one planetary gear set 310 is used to drive the sun gear 323 of the other planetary gear set 320. The center hole 3213 of the planet carrier 321 of the other planetary gear set 320 is used to fix the half shaft 50 of the wheel 40 of the electric vehicle 1. The inner side of the other end 3143 of the planet carrier 314 of one planetary gear set 310 is used to accommodate the sun gear 311 of one planetary gear set 310.

[0264] In this embodiment, the planetary reducer 300 further includes another planetary gear set 320. The outer circumferential surface of one end 3142 of the planet carrier 314 of one planetary gear set 310 is used to drive the sun gear 323 of the other planetary gear set 320, so that the power transmitted by one planetary gear set 310 can be transmitted to the sun gear 323 of the other planetary gear set 320 through the planet carrier 314 of one planetary gear set 310, thereby driving the sun gear 323 and planet gears 324 of the other planetary gear set 320 to move, so that the planetary reducer 300 can achieve two-stage reduction.

[0265] In this embodiment, the sun gear 323 of the secondary planetary gear set 320 is fixed on the outer circumferential surface of one end 3142 of the planet carrier 314 of the planetary gear set 310, and the sun gear 311 of the motor shaft 210 is accommodated inside the other end 3143 of the planet carrier 314 of the planetary gear set 310. This also makes the axial arrangement of the secondary planetary gear sets 310 and 320 more compact.

[0266] In this embodiment, the center hole 3213 of the planet carrier 321 of another planetary gear set 320 is used to fix the half shaft 50 of the wheel 40 of the electric vehicle 1. By directly fixing the half shaft 50 of the wheel 40 of the electric vehicle 1 in the center hole 3213 of the planet carrier 321 of another planetary gear set 320, the use of additional splines can be reduced. It also helps to make the transmission between the planetary reducer 300 and the half shaft 50 of the wheel 40 of the electric vehicle more stable, improve the critical speed of the drive motor, and improve the overall vehicle performance.

[0267] In this embodiment, the inner side of the other end 3143 of the planet carrier 314 of a planetary gear set 310 is used to accommodate the sun gear 311 of the planetary gear set 310, making the structure of the planetary gear set 310 more compact and making it easier for the sun gear 311 of the planetary gear set 310 to transmit power to the planet gears 312 of the planetary gear set 310 through the planet carrier 314 of the planetary gear set 310.

[0268] In one embodiment, as shown in FIG4, the inner wall of the reducer housing 500 includes an annular protrusion 517. As shown in FIG3 and FIG4, the annular protrusion 517 protrudes away from the rotor 230 along the axial direction O of the powertrain 20. The inner peripheral surface of the annular protrusion 517 is used to fix the gear ring 313 of a planetary gear set 310, and the outer peripheral surface of the annular protrusion 517 is used to fix the bearing 5151 of the planet carrier 321 of another planetary gear set 320.

[0269] In this embodiment, the inner circumferential surface of the annular protrusion 517 is used to fix the gear ring 313 of one planetary gear set 310, and the outer circumferential surface of the annular protrusion 517 is used to fix the bearing 5151 of the planet carrier 321 of another planetary gear set 320. This allows the arrangement of the planet carrier 321 of the other planetary gear set 320 to utilize the axial space outside the gear ring 313 of one planetary gear set 310, making the arrangement of one planetary gear set 310 and the other planetary gear set 320 more compact. This allows for a smaller axial dimension of the planetary reducer 300, making the process of power transmission from the motor shaft 210 to the half-shaft 50 of the wheel 40 of the electric vehicle 1 more stable, which is beneficial for increasing the critical speed of the rotor 230. The smaller axial dimension of the planetary reducer 300 also helps to shorten the axial length of the powertrain 20 and optimize the layout of the powertrain 20 within the vehicle.

[0270] In one embodiment, as shown in FIG4, a bearing 3212 of the planet carrier 321 of another planetary gear set 320 is fixed in the center hole 3141 of one end 3142 of the planet carrier 314 of the planetary gear set 310. The end face of one end 211 of the motor shaft 210 includes an axial through hole 211a. The opening of the axial through hole 211a faces the center hole 3141 of one end 3142 of the planet carrier 314 of the planetary gear set 310. The axial through hole 211a is used to output the oil from the internal oil passage 216 of the motor shaft 210 to the center hole 3141.

[0271] In this embodiment, a bearing 3212 of the planet carrier 321 of another planetary gear set 320 is fixed in the center hole 3141 of one end 3142 of the planet carrier 314 of a planetary gear set 310. The end face of one end 211 of the motor shaft 210 includes an axial through hole 211a. The opening of the axial through hole 211a faces the center hole 3141 of one end 3142 of the planet carrier 314 of a planetary gear set 310, so that the oil in the internal oil passage 216 of the motor shaft 210 can be input into the center hole 3141 of one end 3142 of the planet carrier 314 of a planetary gear set 310 through the axial through hole 211a, thereby lubricating a bearing 3212 of the planet carrier 321 of the other planetary gear set 320.

[0272] In one embodiment, the center hole 3141 at one end 3142 of the planet carrier 314 of a planetary gear set 310 can also be referred to as the center hole 3141 inside the fixing protrusion 3140 of the planet carrier 314 in the first-stage planetary gear set 310.

[0273] Figure 15 is a partial enlarged view of the M3 section of the planetary reducer 300 and the motor shaft 210 in Figure 4.

[0274] In one embodiment, as shown in Figures 4 and 15, the planet carrier 321 of another planetary gear set 320 includes a half-shaft hole 3213 and a sealing member 3216. One opening 3217 of the half-shaft hole 3213 extends out of the reducer housing 500 to accommodate the half-shaft 50 of the wheel 40. The other opening 3218 of the half-shaft hole 3213 faces the center hole 3141 of one end 3142 of the planet carrier 314 of one planetary gear set 310. One end 3219 of the sealing member 3216 is used to block the other opening 3218 of the half-shaft hole 3213, and the other end 3220 of the sealing member 3216 is used to fix a bearing 3212 of the planet carrier 321 of the other planetary gear set 320.

[0275] In this embodiment, one opening 3217 of the half-shaft hole 3213 extends out of the reducer housing 500 to accommodate the half-shaft 50 of the wheel 40, and the other opening 3218 of the half-shaft hole 3213 faces the center hole 3141 of one end 3142 of the planet carrier 314 of a planetary gear set 310. One end 3219 of the sealing member 3216 is used to block the other opening 3218 of the half-shaft hole 3213, so that the one end 3219 of the sealing member 3216 can block the oil flowing from the internal oil passage 216 of the motor shaft 210 into the center hole 3141 of one end 3142 of the planet carrier 314 of the planetary gear set 310, thereby preventing the oil in the internal oil passage 216 of the motor shaft 210 from leaking from the half-shaft hole 3213.

[0276] In this embodiment, the other end 3220 of the sealing member 3216 is used to fix a bearing 3212 of the planet carrier 321 of another planetary gear set 320. The bearing 3212 of the planet carrier 321 of the other planetary gear set 320 is also fixed to the center hole 3141 of one end 3142 of the planet carrier 314 of a planetary gear set 310, allowing the planet carrier 321 of the other planetary gear set 320 to rotate relative to the planet carrier 314 of the first planetary gear set 310. This also allows the bearing 3212 of the planet carrier 321 of the other planetary gear set 320, fixed to the other end 3220 of the sealing member 3216, to receive oil from the internal oil passage 216 of the motor shaft 210 within the center hole 3141 of one end 3142 of the planet carrier 314 of the first planetary gear set 310 for lubrication.

[0277] In one embodiment, the half-shaft hole 3213 of the planet carrier 321 of another planetary gear set 320 may also be referred to as the center hole 3213 of the planet carrier 321 of another planetary gear set 320.

[0278] In one embodiment, as shown in Figures 4 and 15, the sealing member 3216 includes a positioning groove 3221. The groove opening of the positioning groove 3221 is opposite to a planetary gear set 310 along the axial direction O of the powertrain 20. The inner diameter of the positioning groove 3221 is smaller than the inner diameter of the half-shaft hole 3213. The positioning groove 3221 is used to accommodate a portion of the half-shaft 50 of the wheel 40 and restrict the movement of the half-shaft 50 along the radial direction R of the powertrain 20.

[0279] In this embodiment, by extending the half-shaft 50 through the opening of the positioning groove 3221 into the positioning groove 3221 of the sealing member 3216, compared to positioning the half-shaft 50 outside the reducer housing 500 and the planetary reducer 300, the axial length between the rotor 230 of the drive motor 200 and the half-shaft 50 can be shortened, the power transmission stability can be improved, and the critical speed of the rotor 230 can be increased.

[0280] In this embodiment, the inner diameter of the positioning groove 3221 is smaller than the inner diameter of the half-shaft hole 3213. The positioning groove 3221 is used to accommodate a part of the half-shaft 50 of the wheel 40 and restrict the movement of the half-shaft 50 along the radial R of the powertrain 20. This helps to make the transmission between the other planetary gear set 320 and the half-shaft 50 of the wheel 40 more stable and improves the reliability of the powertrain 20.

[0281] In one embodiment, as shown in Figures 4 and 15, the sealing member 3216 further includes a thrust bearing groove 3222. The groove opening of the thrust bearing groove 3222 faces the sun gear 323 of another planetary gear set 320 along the axial direction O of the powertrain 20. The thrust bearing groove 3222 is used to accommodate a thrust needle roller bearing 3223, which is used to rotatably connect the sun gear 323 of the other planetary gear set 320 and the sealing member 3216. The thrust bearing groove 3222 surrounds the outer periphery of the positioning groove 3221, and the projection of the positioning groove 3221 and the thrust bearing groove 3222 at least partially overlaps along the radial direction R of the powertrain 20.

[0282] In this embodiment, the thrust needle roller bearing 3223 is used to rotatably connect the sun gear 323 and the sealing member 3216 of another planetary gear set 320, so that the sun gear 323 and the planet carrier 321 of the other planetary gear set 320 can rotate respectively.

[0283] In this embodiment, the thrust bearing groove 3222 surrounds the outer periphery of the positioning groove 3221. The projection of the positioning groove 3221 and the thrust bearing groove 3222 along the radial R of the powertrain 20 at least partially overlaps, which can shorten the axial length between the rotor 230 and the half shaft 50, improve the stability of power transmission, and help to increase the critical speed of the rotor 230.

[0284] In one embodiment, as shown in FIG4, the planet carrier 321 of the other planetary gear set 320 further includes another thrust bearing groove 3228 on the side opposite to the motor shaft 210. The other thrust bearing groove 3228 is used to accommodate a thrust needle roller bearing 3229. Along the axial direction O of the powertrain 20, the two sides of the thrust needle roller bearing 3229 contact the bottom of the second groove 522 of the second housing 520 and the planet carrier 321 of the other planetary gear set 320, respectively, so that the planet carrier 321 of the other planetary gear set 320 can rotate relative to the second housing 520.

[0285] In one embodiment, thrust needle roller bearings 3223 and 3229 can axially limit and fix the planet carrier 321 of another planetary gear set 320.

[0286] In one embodiment, the internal oil passage 216 of the motor shaft 210 can be formed by providing an oil guide pipe 700 in the shaft cavity 213 of the motor shaft 210, as shown in FIG3. The oil guide pipe 700 is used to receive the oil conveyed by the internal oil passage of the housing 20a of the powertrain 20. The oil in the oil guide pipe 700 is used to cool the rotor 230 of the drive motor 200 and lubricate the gear set of the planetary reducer 300.

[0287] Figure 18 is a partial enlarged view of the M4 section of the powertrain 20 in Figure 3.

[0288] In one embodiment, as shown in FIG3, the motor cavity 400a and the reducer cavity 500a of the housing 20a of the powertrain 20 are arranged adjacent to each other along the axial direction O of the powertrain 20. As shown in FIG3, FIG9, FIG17 and FIG18, the housing 20a is also used to fix the oil guide pipe 700. The oil guide pipe 700 is used to deliver oil to at least one of the motor rotor 230 or the reducer 300. One end 720 of the oil guide pipe 700 is used to fixally connect the housing 20a of the powertrain 20 and to receive oil through the internal flow channel 420 of the motor housing 400. The other end 730 of the oil guide pipe 700 extends into the reducer cavity 500a through the shaft cavity 213 of the motor shaft 210 along the axial direction O of the drive motor 200.

[0289] In this embodiment, the housing 20a is also used to fix the oil guide pipe 700. By fixing the oil guide pipe 700 with the housing 20a of the powertrain 20, the oil guide pipe 700 can be stationary relative to the motor shaft 210. Compared to the situation where the oil guide pipe 700 rotates with the motor shaft 210, resulting in a decrease in the amount of oil input to the reducer 300, the stationary oil guide pipe 700 can increase the flow rate of oil delivered to the reducer cavity 500a. This ensures that even when the motor shaft 210 rotates at high speed, the oil in the oil guide pipe 700 will not be thrown out of the oil guide pipe 700 with the rotation of the motor shaft 210. This allows more oil flowing in the oil guide pipe 700 to flow into the reducer cavity 500a to lubricate the reducer 300, which is beneficial to ensuring the normal operation of the reducer 300.

[0290] In this embodiment, the oil guide pipe 700 is fixed to the housing 20a, making the oil guide pipe 700 stationary. This eliminates the need for a clearance between the oil guide pipe 700 and the shaft cavity 213 of the motor shaft 210, ensuring that only a very small amount of oil leaks between the shaft cavity 213 of the motor shaft 210 and the outer wall of the oil guide pipe 700. The stationary position of the oil guide pipe 700 also reduces the risk of wear and dislodgement caused by the rotation of the motor shaft 210, thus improving the reliability of the powertrain 20.

[0291] In this embodiment, the oil guide pipe 700 is used to supply oil to at least one of the motor rotor 230 or the reducer 300, thereby cooling the motor rotor 230 and preventing the drive motor 200 from malfunctioning due to overheating. It can also lubricate the gear set of the reducer 300, ensuring the normal operation of the reducer 300.

[0292] In this embodiment, one end 720 of the oil guide pipe 700 is used to fixally connect the housing 20a of the powertrain 20 and to receive oil through the internal flow channel 420 of the motor housing 400. The other end 730 of the oil guide pipe 700 extends along the axial direction O of the drive motor 200 through the shaft cavity 213 of the motor shaft 210 into the reducer cavity 500a, so that one end 720 of the oil guide pipe 700 can receive oil from the internal flow channel 420 of the motor housing 400, so that the oil flows in the oil guide pipe 700 and is output to the reducer cavity 500a through the other end 730 of the oil guide pipe 700, thereby lubricating the gear set of the reducer 300 in the reducer cavity 500a. Furthermore, by arranging the oil guide pipe 700 inside the shaft cavity 213 of the motor shaft 210, the space inside the shaft cavity 213 of the motor shaft 210 can be fully utilized, and it is also more convenient for the oil guide pipe 700 to transport the oil to the motor rotor 230 fixed to the motor shaft 210 for cooling.

[0293] In this embodiment, by fixing one end 720 of the oil guide pipe 700 to the housing 20a of the powertrain 20 and receiving oil through the internal flow channel 420 of the motor housing 400, the oil guide pipe 700 is fixed to the housing 20a but not directly fixed to the motor shaft 210. This allows the oil guide pipe 700 to remain relatively stationary when the motor shaft 210 rotates, preventing the oil in the oil guide pipe 700 from being completely thrown out with the high-speed rotation of the motor shaft 210, and allowing the oil to flow to the other end of the oil guide pipe 700. 730, while the other end 730 of the oil guide pipe 700 passes through the shaft cavity 213 of the motor shaft 210 and extends into the reducer cavity 500a along the axial direction O of the drive motor 200, so that the oil flowing into the oil guide pipe 700 from one end 720 can flow into the reducer cavity 500a through the other end 730 of the oil guide pipe 700 to lubricate the gear set of the reducer 300. Thus, the oil in the oil guide pipe 700 can both cool the motor rotor 230 and lubricate the reducer 300.

[0294] In one embodiment, as shown in Figures 3 and 18, the cavity wall of the motor cavity 400a includes a motor shaft bearing groove 410. The groove opening 411 of the motor shaft bearing groove 410 faces the motor rotor 230 along the axial direction O of the drive motor 200. The motor shaft bearing groove 410 is used to fix the outer ring of the motor bearing 412, the inner ring of the motor bearing 412 is used to fix the motor shaft 210, and the bottom 413 of the motor shaft bearing groove 410 is used to fix one end 720 of the oil guide pipe 700.

[0295] In this embodiment, the slot 411 of the motor shaft bearing groove 410 faces the motor rotor 230 along the axial direction O of the drive motor 200, thereby facilitating the fixing of the motor bearing 412 in the motor shaft bearing groove 410 to the motor shaft 210 that fixes the motor rotor 230.

[0296] In this embodiment, the motor shaft bearing groove 410 is used to fix the outer ring of the motor bearing 412, the inner ring of the motor bearing 412 is fixed to the motor shaft 210, and one end 720 of the oil guide pipe 700 is fixed to the bottom 413 of the groove of the motor shaft bearing groove 410, thereby facilitating the arrangement of the oil guide pipe 700 through the shaft cavity 213 of the motor shaft 210. By fixing one end 720 of the oil guide pipe 700 with the bottom 413 of the groove of the motor shaft bearing groove 410, the oil guide pipe 700 can be in a stationary state relative to the shaft cavity 213 of the motor shaft 210, which is beneficial to deliver more oil in the oil guide pipe 700 to the reducer cavity 500a for lubrication of the gear set of the reducer 300. By fixing one end 720 of the oil guide pipe 700 with the bottom 413 of the groove of the motor shaft bearing groove 410, the arrangement of the oil guide pipe 700 can also utilize the axial space of the motor shaft bearing groove 410, which is beneficial to reducing the axial length of the powertrain 20.

[0297] In one embodiment, as shown in Figures 3 and 18, the bottom 413 of the motor shaft bearing groove 410 includes an oil outlet 414. The oil outlet 414 is used to output oil from the internal flow channel 420 of the motor housing 400. The opening of the oil outlet 414 faces the motor rotor 230 along the axial direction of the powertrain 20. The oil outlet 414 is used to accommodate the embedding of one end 720 of the oil guide pipe 700.

[0298] In this embodiment of the application, the bottom 413 of the motor shaft bearing groove 410 includes an oil outlet hole 414. The bottom 413 of the motor shaft bearing groove 410 is used to fix one end 720 of the oil guide pipe 700, thereby facilitating the rapid delivery of the oil from the internal flow channel 420 of the motor housing 400 output from the oil outlet hole 414 to one end 720 of the oil guide pipe 700.

[0299] In this embodiment, the opening of the oil outlet 414 along the axial direction of the powertrain 20 faces the motor rotor 230, so that the oil output from the oil outlet 414 in the internal flow channel 420 of the motor housing 400 can be delivered to the motor rotor 230 more quickly to cool the motor rotor 230.

[0300] In this embodiment, the oil outlet 414 is used to accommodate the embedding of one end 720 of the oil guide pipe 700, so that the oil output from the oil outlet 414 can be input into one end 720 of the oil guide pipe 700. The embedded connection method can make the gap between the oil outlet 414 and one end 720 of the oil guide pipe 700 smaller, thereby reducing the leakage of oil during the process of outputting oil from the oil outlet 414 to one end 720 of the oil guide pipe 700. This ensures that one end 720 of the oil guide pipe 700 can deliver enough oil to the other end 730 of the oil guide pipe 700, thereby ensuring that the motor rotor 230 has enough oil for cooling and that the gear set of the reducer 300 has enough oil for lubrication.

[0301] In one embodiment, the oil outlet 414 is interference-fitted with one end 720 of the oil guide tube 700, so that there is no gap between the oil outlet 414 and one end 720 of the oil guide tube 700.

[0302] In one embodiment, as shown in Figures 3 and 18, the motor housing 400 includes another motor shaft bearing groove 410. Along the axial direction of the powertrain 20, the groove opening 411 of the other motor shaft bearing groove 410 faces the opening 401 of the motor housing 400. The other motor shaft bearing groove 410 is used to fix the outer ring of another motor bearing 412, and the inner ring of the other motor bearing 412 is used to fix the other end 212 of the motor shaft 210. The bottom 413 of the other motor shaft bearing groove 410 includes an oil outlet hole 414. Along the axial direction of the powertrain 20, the opening of the oil outlet hole 414 faces the other end 212 of the motor shaft 210. The oil outlet hole 414 is used to output the oil transported by the internal flow channel 420 of the motor housing 400. The motor shaft 210 includes a shaft hole 213, which extends through the motor shaft 210 along the axial direction O of the powertrain 20. The shaft hole 213 is used to transmit the oil output from the oil outlet 414 to the groove 511 to lubricate the planetary gear set 310 of the planetary reducer 300.

[0303] In this embodiment, along the axial direction of the powertrain 20, the slot 411 of the other motor shaft bearing groove 410 faces the opening 401 of the motor housing 400, so that the other motor bearing 412 can be arranged toward the motor rotor 230, making it easier to fix the other motor bearing 412 to the other end 212 of the motor shaft 210 housed in the motor housing 400.

[0304] In this embodiment, the bottom 413 of another motor shaft bearing groove 410 includes an oil outlet hole 414. The opening of the oil outlet hole 414 faces the other end 212 of the motor shaft 210 along the axial direction of the powertrain 20, so as to facilitate the delivery of the oil transmitted by the internal flow channel 420 of the motor housing 400 to the other end 212 of the motor shaft 210 through the oil outlet hole 414.

[0305] In this embodiment, the motor shaft 210 includes a shaft hole 213 that extends through the motor shaft 210 along the axial direction O of the powertrain 20, allowing oil to flow within the motor shaft 210. The shaft hole 213 is used to transmit the oil output from the oil outlet 414 to the groove 511 to lubricate the planetary gear set 310 of the planetary reducer 300. This allows the oil transmitted through the internal flow channel 420 of the motor housing 400 to be transmitted through the other end 212 of the motor shaft 210 to one end 211 of the motor shaft 210, and then flow into the groove 511 of the first housing 510 to lubricate the planetary gear set 310 of the planetary reducer 300. Furthermore, since one end 211 of the motor shaft 210 serves as the sun gear 311 for meshing with the planetary gears 312 of the planetary reducer 300, oil is supplied from the other end 212 of the motor shaft 210 to the planetary gear set 310 at one end 211 of the motor shaft 210 through the oil outlet 414 of the motor housing 400, eliminating the need for additional oil pipelines and resulting in a compact oil circuit structure.

[0306] In one embodiment, the shaft hole 213 of the motor shaft 210 extends through the motor shaft 210 along the axial direction O of the powertrain 20. The shaft hole 213 of the motor shaft 210 may also be referred to as the shaft cavity 213 of the motor shaft 210.

[0307] In one embodiment, as shown in Figures 3 and 18, the bottom 413 of the motor shaft bearing groove 410 includes a protrusion 415. The protrusion 415 protrudes towards the opening 401 of the motor housing 400 along the axial direction of the powertrain 20. An oil outlet 414 is distributed on the end face of the protrusion 415. The oil outlet 414 is connected to the internal flow channel 420 of the motor housing 400 through the internal flow channel of the protrusion 415 to receive oil. The outer peripheral surface of the protrusion 415 and the inner wall of the shaft hole 213 are used to fix the inner ring of the conductive element 430. The conductive element 430 is located between the outer peripheral surface of the protrusion 415 and the inner wall of the shaft hole 213.

[0308] In this embodiment, the bottom 413 of another motor shaft bearing groove 410 includes a protrusion 415. Along the axial direction of the powertrain 20, the protrusion 415 protrudes toward the opening 401 of the motor housing 400. Oil outlet holes 414 are distributed on the end face of the protrusion 415. The oil outlet holes 414 are connected to the internal flow channel 420 of the motor housing 400 through the internal flow channel of the protrusion 415 to receive oil. The protrusion 415 protrudes toward the opening 401 of the motor housing 400, that is, the protrusion 415 protrudes toward the motor shaft 210, which is more conducive to the corresponding delivery of the oil in the internal flow channel 420 of the motor housing 400 to the shaft hole 213 of the motor shaft 210 through the internal flow channel of the protrusion 415.

[0309] In this embodiment, the outer peripheral surface of the protrusion 415 and the inner wall of the shaft hole 213 are used to fix the conductive element 430. The conductive element 430 is located between the outer peripheral surface of the protrusion 415 and the inner wall of the shaft hole 213. The protrusion 415 where the oil outlet hole 414 is located and the inner wall of the shaft hole 213 of the motor shaft 210 are reused to fix the conductive element 430. This allows the protrusion 415 to not only transport oil but also contact the conductive element 430 to achieve grounding of the conductive element 430 and the motor shaft 210. It also allows the arrangement of the conductive element 430 to utilize the space of the shaft hole 213 of the motor shaft 210 along the radial R direction of the powertrain 20. This ensures that the arrangement of the conductive element 430 does not occupy additional space of the motor shaft 210 along the axial O direction of the powertrain 20. In other words, grounding can be achieved without occupying additional axial dimensions of the powertrain 20.

[0310] If the conductive element 430 is to be arranged on the outer periphery of the other end 212 of the motor shaft 210, on the one hand, the axial space for arranging the other motor bearing 412 can be compressed while keeping the length of the motor shaft 210 unchanged. However, the interval between the bearing groove 410 of the other motor shaft and the rotor 230 is small, making this difficult to achieve. On the other hand, the length of the motor shaft 210 can be extended so that there is enough space on the outer periphery of the other end 212 of the motor shaft 210 to arrange the conductive element 430 and the other motor bearing 412. However, this would increase the axial dimension of the powertrain 20, which is not conducive to the layout of the powertrain 20 in the vehicle.

[0311] In one embodiment, as shown in FIG18, the outer diameter of the portion of the protrusion 415 used to fix the conductive element 430 along the radial direction R of the powertrain 20 is smaller than the inner diameter of the portion of the shaft hole 213 used to fix the conductive element 430. This allows the conductive element 430 to be arranged between the outer ring of the protrusion 415 and the inner wall of the shaft hole 213 of the motor shaft 210. This arrangement of the conductive element 430 does not require additional space occupied by the motor shaft 210 outside the axial direction O of the powertrain 20, resulting in a smaller axial dimension of the motor shaft 210 and thus a reduction in the axial dimension of the powertrain 20.

[0312] In one embodiment, as shown in FIG18, the protrusion 415 includes a fixed section 4151 and a connecting section 4152. The connecting section 4152 is connected between the fixed section 4151 and the bottom 413 of the groove of another motor shaft bearing groove 410. The outer diameter of the fixed section 4151 is smaller than the outer diameter of the connecting section 4152. The fixed section 4151 is used to fix the conductive element 430. The projection of the fixed section 4151 along the radial direction R of the powertrain 20 and the groove peripheral wall of the other motor shaft bearing groove 410 at least partially overlaps, so that the conductive element 430 overlaps with the other motor bearing 412 along the radial direction R of the powertrain 20. The conductive element 430 is arranged in the axial space of the other motor bearing 412, which is beneficial to shorten the axial dimension of the powertrain 20.

[0313] In one embodiment, as shown in FIG18, the bottom 413 of the motor shaft bearing groove 410 includes a nozzle 450, which faces the motor rotor 230 along the axial direction O of the powertrain 20, and one end 720 of the oil guide tube 700 is used to accommodate the embedding of the nozzle 450.

[0314] In this embodiment of the application, as shown in Figures 3 and 18, the nozzle 450 is oriented toward the motor rotor 230 along the axial direction O of the powertrain 20, which facilitates the oil pipe 700 at one end 720 to receive the oil sprayed by the nozzle 450, and also makes it easier to deliver the oil to the motor rotor 230 to power the motor rotor 230 to cool down.

[0315] In this embodiment, one end 720 of the oil guide pipe 700 is used to accommodate the embedding of the nozzle 450, which can make the connection gap between the one end 720 of the oil guide pipe 700 and the nozzle 450 smaller, thereby reducing the leakage of oil in the internal flow channel 420 of the motor housing 400 during the process of being transported from the nozzle 450 to the one end 720 of the oil guide pipe 700. This allows almost all of the oil transported by the nozzle 450 to be received by the one end 720 of the oil guide pipe 700, thereby ensuring that the one end 720 of the oil guide pipe 700 can transport enough oil to the other end 730 of the oil guide pipe 700, thereby ensuring that the motor rotor 230 has enough oil for cooling and that the gear set of the reducer 300 has enough oil for lubrication.

[0316] In one embodiment, one end 720 of the oil guide tube 700 is interference-fitted with the nozzle 450, so that there is no gap between the nozzle 450 and one end 720 of the oil guide tube 700.

[0317] In one embodiment, the structure of the nozzle 450 in FIG18 is the same as that of the protrusion 415. In one embodiment, the nozzle 450 and the protrusion 415 are the same structure. In one embodiment, the nozzle 450 and the protrusion 415 are two adjacent structural components.

[0318] In one embodiment, as shown in FIG18, one end 720 of the oil guide tube 700 includes a base 740. The base 740 is used to surround the nozzle 450 fixed to the bottom 413 of the motor shaft bearing groove 410. The base 740 and the outer periphery of the nozzle 450 are fitted with a small gap or a small transition, so that the leakage of oil from the internal flow channel 420 of the motor housing 400 received by one end 720 of the oil guide tube 700 can be minimized, achieving near "zero leakage".

[0319] In one embodiment, the base 740 includes an anti-rotation boss that prevents the oil guide pipe 700 from rotating with the motor shaft 210, thus ensuring that the oil guide pipe 700 remains stationary.

[0320] In one embodiment, as shown in FIG17, the inner diameter of one end 720 of the oil guide tube 700 is larger than the inner diameter of the other end 730 of the oil guide tube 700.

[0321] In this embodiment, as shown in Figures 3, 9, and 18, the inner diameter of one end 720 of the oil guide pipe 700 is larger, which facilitates the receiving of oil output from the internal flow channel 420 of the motor housing 400. The inner diameter of the other end 730 of the oil guide pipe 700 is smaller, which makes the process of the other end 730 of the oil guide pipe 700 passing through the shaft cavity 213 of the motor shaft 210 and extending into the reducer cavity 500a along the axial direction O of the drive motor 200 smoother. The inner diameter of one end 720 of the oil guide pipe 700 is larger than the inner diameter of the other end 730 of the oil guide pipe 700, which can increase the flow rate of oil from one end 720 to the other end 730 of the oil guide pipe 700, and is more conducive to the other end 730 of the oil guide pipe 700 spraying oil into the reducer cavity 500a to lubricate the gear set of the reducer 300.

[0322] In one embodiment, as shown in FIG17, the inner wall of the shaft cavity 213 of the motor shaft 210 is used to fix the outer ring of the oil guide tube bearing 710, and the inner ring of the oil guide tube bearing 710 is used to fix the oil guide tube 700, which passes through the inner ring of the oil guide tube bearing 710.

[0323] In this embodiment, as shown in Figures 3, 9, and 17, the inner wall of the shaft cavity 213 of the motor shaft 210 is used to fix the outer ring of the oil guide tube bearing 710, and the inner ring of the oil guide tube bearing 710 is used to fix the oil guide tube 700. The oil guide tube 700 passes through the inner ring of the oil guide tube bearing 710. The oil guide tube bearing 710 allows the oil guide tube 700 to remain stationary within the shaft cavity 213 of the motor shaft 210 when the motor shaft 210 rotates. This allows more oil in the oil guide tube 700 to be transported more smoothly from one end 720 to the other end 730 of the oil guide tube 700, thereby lubricating the gear set of the reducer 300 in the reducer cavity 500a.

[0324] In one embodiment, as shown in Figures 9 and 18, the shaft hole 213 is used to accommodate the oil guide tube 700 and the oil guide tube bearing 710. The outer peripheral surface of the oil guide tube 700 is used to fix the inner ring of the oil guide tube bearing 710, and the inner wall of the shaft hole 213 is used to fix the outer ring of the oil guide tube bearing 710. The inlet 701 of the oil guide tube 700 is used to receive the oil output from the oil outlet 414. The inlet 701 of the oil guide tube 700 is fixed to the bottom 413 of the groove of another motor shaft bearing groove 410. The outlet 702 of the oil guide tube 700 is used to output oil to the groove 511 to lubricate multiple planetary gears 312. The outlet 702 of the oil guide tube 700 is exposed at one end 211 of the motor shaft 210.

[0325] In this embodiment, the shaft hole 213 is used to accommodate the oil guide tube 700 and the oil guide tube bearing 710. The outer peripheral surface of the oil guide tube 700 is used to fix the inner ring of the oil guide tube bearing 710, and the inner wall of the shaft hole 213 is used to fix the outer ring of the oil guide tube bearing 710. This allows the oil guide tube 700 in the shaft hole 213 to remain stationary without rotating with the motor shaft 210, thus preventing the oil guide tube 700 from being damaged by the other end 212 of the motor shaft 210 when the motor shaft 210 rotates at high speed. The oil entering the oil guide pipe 700 through the inlet 701 is thrown out by the motor shaft 210 and cannot be delivered to the planetary reducer 300 located at one end 211 of the motor shaft 210 through the outlet 702 of the oil guide pipe 700. This allows the oil transmitted from the inlet 701 of the oil guide pipe 700 to be transmitted from the outlet 702 of the oil guide pipe 700 to the multiple planetary gears 312 in the groove 511, so as to lubricate the planetary gear set 310 of the planetary reducer 300 and ensure the normal operation of the planetary reducer 300.

[0326] In this embodiment, the outlet 702 of the oil guide pipe 700 is exposed at one end 211 of the motor shaft 210, so that the oil in the oil guide pipe 700 is not blocked by the inner wall of the shaft hole 213 and can be sprayed directly from the outlet 702 of the oil guide pipe 700 to the multiple planetary gears 312 of the planetary reducer 300, which is beneficial to lubricate the multiple planetary gears 312 of the planetary reducer 300.

[0327] In one embodiment, as shown in FIG17, the other end 730 of the oil guide tube 700 further includes another nozzle 731, the inner ring of the oil guide tube bearing 710 is used to fix the other nozzle 731 of the oil guide tube 700, and the outlet of the other nozzle 731 is the outlet 702 of the oil guide tube 700.

[0328] In one embodiment, as shown in FIG17, the outer peripheral surface of the oil guide tube 700 includes an annular protrusion 750, the outer diameter of which is smaller than the inner diameter of the shaft cavity 213 of the motor shaft 210 and larger than the inner diameter of the inner ring of the oil guide tube bearing 710.

[0329] In this embodiment, the outer diameter of the annular protrusion 750 is smaller than the inner diameter of the shaft cavity 213 of the motor shaft 210, allowing the annular protrusion 750 to be arranged within the shaft cavity 213 of the motor shaft 210. The outer diameter of the annular protrusion 750 is larger than the inner diameter of the inner ring of the oil guide tube bearing 710, allowing the oil guide tube bearing 710 to axially limit the annular protrusion 750 along the axial direction O of the drive motor 200. This, in turn, allows the oil guide tube bearing 710 to axially limit the oil guide tube 700, reducing the axial movement of the oil guide tube 700 and improving the stability of the oil guide tube 700, thereby enhancing the stability and reliability of the powertrain 20.

[0330] In one embodiment, as shown in Figures 17 and 18, the oil guide pipe bearing 710 is also used to electrically connect the motor shaft 210 and the oil guide pipe 700, and the oil guide pipe 700 is also used to electrically connect the motor housing 400.

[0331] In this embodiment, the oil guide bearing 710 is also used to electrically connect the motor shaft 210 and the oil guide 700, so that the shaft voltage on the motor shaft 210 can be conducted to the oil guide 700 through the oil guide bearing 710. The oil guide 700 is also used to electrically connect the motor housing 400, so that the current received by the oil guide 700 from the motor shaft 210 can be conducted to the motor housing 400, thereby grounding the motor shaft 210 and preventing the motor bearing 412 fixed to the motor shaft 210 from being electro-corroded, thus improving the reliability of the powertrain 20.

[0332] In this embodiment, the reuse of the oil guide bearing 710 as a conductive bearing not only reduces the number of parts used, but also reduces the axial space of the motor shaft 210 occupied by the conductive bearing on the outer circumferential surface of the motor shaft 210. This makes the arrangement of other parts fixed to the motor shaft 210 more compact, so that the arrangement requirements can be met by using a shorter motor shaft 210, thereby shortening the axial dimension of the powertrain 20 and facilitating the miniaturization of the powertrain 20.

[0333] In one embodiment, the oil guide 700 is a metal tube, which allows the oil guide 700 to conduct current from the motor shaft 210.

[0334] In one embodiment, as shown in Figures 3 and 17, the outer peripheral surface of the oil guide tube 700 includes a plurality of first through holes 760, each first through hole 760 penetrating the tube wall of the oil guide tube 700. The plurality of first through holes 760 are distributed in the portion of the oil guide tube 700 located in the motor cavity 400a, and the diameter of each first through hole 760 is smaller than the inner diameter of the other end 730 of the oil guide tube 700.

[0335] In this embodiment, each first through hole 760 penetrates the wall of the oil guide pipe 700, allowing the oil in the oil guide pipe 700 to flow out of the oil guide pipe 700 through the first through hole 760. Multiple first through holes 760 are distributed in the portion of the oil guide pipe 700 located in the motor cavity 400a, allowing the oil output from the first through holes 760 to be transported to the motor rotor 230 in the motor cavity 400a via a short path and more quickly for cooling, thereby improving the cooling efficiency of the powertrain 20.

[0336] In this embodiment, the diameter of each first through hole 760 is smaller than the inner diameter of the other end 730 of the oil guide pipe 700. The smaller diameter of the first through hole 760 results in less oil output from the first through hole 760 within the oil guide pipe 700, thus allowing more oil to flow to the other end 730 of the oil guide pipe 700. This results in more oil entering the reducer cavity 500a, meeting the lubrication requirements of the reducer 300 and ensuring its normal operation. Conversely, if the diameter of the first through hole 760 is larger than the diameter of the other end 730 of the oil guide pipe 700, the flow resistance of the oil through the first through hole 760 is smaller, causing more oil to flow from the first through hole 760 to the motor rotor 230 within the oil guide pipe 700. This results in less oil flowing to the other end 730 of the oil guide pipe 700, potentially leading to insufficient lubrication of the gear set in the reducer 300 and reduced operating efficiency.

[0337] In one embodiment, as shown in Figures 3 and 17, the outer peripheral surface of the oil guide pipe 700 includes a plurality of second through holes 770, each second through hole 770 penetrating the pipe wall of the oil guide pipe 700. The plurality of second through holes 770 are distributed in the portion of the oil guide pipe 700 located in the reducer cavity 500a, and the number of first through holes 760 is less than the number of second through holes 770.

[0338] In this embodiment, each second through hole 770 penetrates the wall of the oil guide pipe 700, allowing oil in the oil guide pipe 700 to flow out through the second through hole 770. Multiple second through holes 770 are distributed in the portion of the oil guide pipe 700 located in the reducer cavity 500a, enabling oil output from the second through holes 770 to be delivered to the reducer cavity 500a via a short path and faster for lubrication of the gear set in the reducer 300, thereby improving the lubrication efficiency of the powertrain 20.

[0339] In this embodiment, the number of first through holes 760 is less than the number of second through holes 770. This is beneficial because the amount of oil flowing from the first through holes 760 to the motor rotor 230 is less than the amount of oil flowing from the second through holes 770 to the gear set of the reducer 300. This ensures that the gear set of the reducer 300 can receive more oil and be fully lubricated, which is beneficial to the normal operation of the reducer 300.

[0340] In one embodiment, as shown in FIG17, the diameter of each first through hole 760 is smaller than the diameter of each second through hole 770.

[0341] In this embodiment of the application, as shown in Figures 3 and 17, the diameter of the first through hole 760 is relatively small, resulting in a larger flow resistance for the oil flowing through the first through hole 760. The diameter of the second through hole 770 is relatively large, resulting in a smaller flow resistance for the oil flowing through the second through hole 770. Making the diameter of each first through hole 760 smaller than the diameter of each second through hole 770 is beneficial for more oil in the oil guide pipe 700 to flow out from the second through hole 770 with smaller flow resistance to the reducer cavity 500a. This ensures that the reducer 300 in the reducer cavity 500a can be lubricated by more oil, which is beneficial for the normal operation of the reducer 300.

[0342] In one embodiment, as shown in Figures 3 and 17, at low temperatures, the oil in the oil guide pipe 700 has a high viscosity and a thick boundary layer. The diameter of the first through hole 760 is small, making it difficult for the oil to flow out through the first through hole 760 to the motor rotor 230. Instead, more oil is transported through the other end 730 of the oil guide pipe 700 to the reducer cavity 500a for lubrication of the gear set in the reducer 300. At high temperatures, the oil in the oil guide pipe 700 has a low viscosity. Even with the small diameter of the first through hole 760, the oil can still flow out through the first through hole 760 to cool the motor rotor 230. This allows the oil guide pipe 700 within the powertrain 20 to achieve different flow distributions in high and low temperature scenarios, resulting in optimal cooling and lubrication of the powertrain 20.

[0343] In one embodiment, as shown in Figures 4, 16 and 17, the outer peripheral surface of the motor shaft 210 includes a plurality of third through holes 780, each third through hole 780 connecting to the shaft cavity 213 of the motor shaft 210, and the diameter of each third through hole 780 being greater than or equal to the diameter of each first through hole 760.

[0344] In this embodiment, the outer peripheral surface of the motor shaft 210 includes a plurality of third through holes 780, each third through hole 780 connecting to the shaft cavity 213 of the motor shaft 210, so that the oil in the shaft cavity 213 of the motor shaft 210 can be output through the third through hole 780, thereby cooling the motor rotor 230 of the drive motor 200.

[0345] In this embodiment, the diameter of each third through hole 780 is greater than or equal to the diameter of each first through hole 760. The smaller diameter of the first through hole 760 allows for a smaller amount of oil output from the first through hole 760, resulting in a larger amount of oil delivered from the oil guide pipe 700 to the reducer 300, ensuring sufficient lubrication of the gear set of the reducer 300. The larger diameter of the third through hole 780 allows all or most of the oil output from the first through hole 760 of the oil guide pipe 700 to be delivered to the motor rotor 230 through the third through hole 780, ensuring good cooling effect of the oil on the motor rotor 230 without affecting the amount of lubricating oil in the reducer 300.

[0346] In one embodiment, as shown in Figures 4, 16 and 17, along the axial direction O of the powertrain 20, the motor shaft oil hole 215 and a plurality of third through holes 780 are arranged on both sides of the first housing 510.

[0347] In one embodiment, as shown in Figures 4 and 17, the reducer 300 includes a primary planetary gear set 310 and a secondary planetary gear set 320. The motor shaft 210 is used to fix the sun gear 311 of the primary planetary gear set 310. The planet carrier 314 of the primary planetary gear set 310 is used to fix the sun gear 323 of the secondary planetary gear set 320. The center hole 3213 of the planet carrier 321 of the secondary planetary gear set 320 is used to couple the half shaft 50 of the wheel 40 of the electric vehicle 1. The other end 730 of the oil guide pipe 700 extends into the center hole 3141 of the planet carrier 314 of the primary planetary gear set 310.

[0348] In this embodiment, the motor shaft 210 is used to fix the sun gear 311 of the first-stage planetary gear set 310, so that the kinetic energy of the motor rotor 230 can be transferred to the sun gear 311 of the first-stage planetary gear set 310, causing the planet gears 312 of the first-stage planetary gear set 310 to rotate. The planet carrier 314 of the first-stage planetary gear set 310 is used to fix the sun gear 323 of the second-stage planetary gear set 320, so that the first-stage planetary gear set 310 can transfer the power from the motor shaft 210 to the second-stage planetary gear set 320, causing the planet gears 324 of the second-stage planetary gear set 320 to rotate. The center hole 3213 of the planet carrier 321 of the second-stage planetary gear set 320 is used to couple the half-shaft 50 of the wheel 40 of the electric vehicle 1, so that the planet carrier 321 of the second-stage planetary gear set 320 can transfer the power to the half-shaft 50 of the wheel 40 of the electric vehicle 1, thereby enabling the power after being reduced by the reducer 300 to drive the wheel 40.

[0349] In this embodiment, the other end 730 of the oil guide pipe 700 extends into the center hole 3141 of the planet carrier 314 of the first-stage planetary gear set 310, so that the other end 730 of the oil guide pipe 700 can be exposed to the sun gear 311 of the first-stage planetary gear set 310. This allows the oil flowing out from the other end 730 of the oil guide pipe 700 when the motor shaft 210 rotates at high speed to be sprayed directly onto the outside of the motor shaft 210 instead of being stuck in the shaft cavity 213 of the motor shaft 210. This makes it easier for the oil in the oil guide pipe 700 to lubricate the sun gear 311 of the first-stage planetary gear set 310 and the multiple planetary gears 312 distributed around the sun gear 311, thereby improving the lubrication efficiency of the reducer 300.

[0350] In one embodiment, as shown in Figures 3 and 18, the housing 20a of the powertrain 20 includes a motor housing 400 and two reducer housings 500. The motor housing 400 includes a partition 460 and two openings 401. The partition 460 is used to divide the motor housing 400 into two motor cavities 400a. The two openings 401 are distributed on both sides of the partition 460 along the axial direction O of the powertrain 20. Each reducer housing 500 is used to enclose the opening 401 of one motor cavity 400a and to form one reducer cavity 500a. The partition 460 includes two sides 461, which are distributed opposite to each other along the axial direction O of the powertrain 20. The two sides 461 are used to fix two oil guide pipes 700 respectively. The two oil guide pipes 700 are used to receive oil conveyed by the same internal flow channel 420 in the partition 460. The two oil guide pipes 700 pass through the motor shafts 210 of the two drive motors 200 in opposite directions and convey oil to the two reducer chambers 500a respectively.

[0351] In this embodiment, the partition 460 divides the motor housing 400 into two motor cavities 400a. Two openings 401 are distributed on both sides of the partition 460 along the axial direction O of the powertrain 20, thereby facilitating the installation of the motor stator 220 and motor rotor 230 of the drive motor 200 into the motor housing 400 from the direction of each opening 401. Each reducer housing 500 is used to enclose the opening 401 of one motor cavity 400a and to form a reducer cavity 500a, thereby allowing the two reducers 300 and the two drive motors 200 to be arranged along the axial direction O of the powertrain 20.

[0352] In this embodiment, the partition 460 includes two sides 461, which are distributed opposite to each other along the axial direction O of the powertrain 20. The two sides 461 are respectively used to fix two oil guide pipes 700. The two oil guide pipes 700 are used to receive oil transported from the same internal flow channel 420 in the partition 460, allowing the two oil guide pipes 700 to receive oil in the same internal flow channel 420 of the partition 460, thereby simplifying the arrangement of oil pipelines within the partition 460. The two oil guide pipes 700 pass through the motor shafts 210 of the two drive motors 200 in opposite directions, respectively transporting oil to the two reducer cavities 500a. This allows the oil transported from the same internal flow channel 420 in the partition 460 to be split through the two oil guide pipes 700, entering the two motor cavities 400a and the two reducer cavities 500a respectively, achieving parallel flow. This reduces the system resistance of the oil flow within the housing 20a of the powertrain 20 and also helps improve the cooling and lubrication efficiency of the powertrain 20.

[0353] The powertrain and electric vehicle provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and embodiments of this application. The description of the embodiments above is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in specific embodiments and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A powertrain with a two-stage planetary coaxial reducer, characterized in that, The powertrain is used to drive an electric vehicle. The powertrain housing includes a motor housing and a reducer housing. The interior of the motor housing houses the stator of the drive motor, and the central hole of the stator houses the rotor. The interior of the reducer housing houses the first-stage and second-stage planetary gear sets of the planetary coaxial reducer. The first-stage planetary gear set is used to drive the second-stage planetary gear set and the motor shaft of the drive motor. The second-stage planetary gear set is used to drive the wheels of the electric vehicle. Wherein: The motor housing is used to fix the reducer housing of the powertrain. The reducer housing is used to enclose the opening of the motor housing and the bearing for fixing the motor shaft. The motor rotor and the gear set of the first-stage planetary gear set are arranged inside the motor housing on both sides of the bearing of the motor shaft along the axial direction of the drive motor.

2. The powertrain according to claim 1, characterized in that, The motor housing surrounds the end winding of the motor stator on the side facing the planetary coaxial reducer, and the end winding of the motor stator on the side facing the planetary coaxial reducer surrounds the bearing of the motor shaft circumferentially around the powertrain.

3. The powertrain according to any one of claims 1-2, characterized in that, The outer diameter of the gear ring of the first-stage planetary gear set is less than or equal to the inner diameter of the center hole of the motor stator, and the outer diameter of the gear ring of the second-stage planetary gear set is greater than the inner diameter of the center hole of the motor stator and less than or equal to the outer diameter of the motor stator.

4. The powertrain according to any one of claims 1-3, characterized in that, The reducer housing on the side facing the drive motor is also used to fix the outer ring of a resolver sensor. The inner ring of the resolver sensor is arranged along the axial direction of the drive motor between the bearing of the motor shaft and the motor rotor. The motor shaft is used to pass through the inner ring of the resolver sensor and extend into the interior of the reducer housing to drive the first-stage planetary gear set.

5. The powertrain according to claim 4, characterized in that, The reducer housing also includes a motor shaft bearing groove on the side facing the drive motor. The motor shaft bearing groove is used to fix the outer ring of the bearing on the motor shaft, and the inner ring of the bearing on the motor shaft is used to fit onto the motor shaft. Wherein: The groove wall of the motor shaft bearing groove is used to fix a sensor bracket, and the sensor bracket is used to fix the outer ring of the resolver sensor and to surround the resolver sensor circumferentially. The bottom of the motor shaft bearing groove includes a through hole, through which the motor shaft extends into the interior of the reducer housing.

6. The powertrain according to claim 4 or 5, characterized in that, One end of the motor shaft that extends into the interior of the reducer housing serves as the sun gear of the first-stage planetary gear set, driving the planet gears of the first-stage planetary gear set.

7. The powertrain according to any one of claims 1-6, characterized in that, The reducer housing includes a first housing and a second housing, wherein the first housing is used to enclose the opening of the motor housing, and the second housing is used to enclose the first housing, wherein: The first housing is recessed in the direction toward the drive motor, forming a first groove on the side of the first housing away from the drive motor. The inner wall of the first groove is used to fix the gear ring of the first-stage planetary gear set.

8. The powertrain according to claim 7, characterized in that, The inner wall of the first groove includes an annular protrusion. The inner circumferential surface of the annular protrusion is used to fix the gear ring of the first-stage planetary gear set, and the outer circumferential surface of the annular protrusion is used to fix a bearing of the planet carrier in the second-stage planetary gear set.

9. The powertrain according to claim 8, characterized in that, The planet carrier in the first-stage planetary gear set includes a fixed protrusion that faces away from the drive motor protrusion. The spline on the outer circumference of the fixed protrusion is used for transmission connection to the sun gear of the second-stage planetary gear set. The inner side of the fixed protrusion has a central hole for accommodating the other bearing of the planet carrier in the second-stage planetary gear set.

10. A powertrain, characterized in that, The powertrain includes a planetary reducer and a drive motor. The reducer housing of the powertrain accommodates two planetary gear sets of the planetary reducer. One planetary gear set is used to drive the motor shaft of the drive motor. The planet carrier of the one planetary gear set is used to drive the sun gear of the other planetary gear set. The planet carrier of the other planetary gear set is used to drive the half-shaft of the electric vehicle's wheel. Wherein: Each planetary gear set includes a planetary shaft with a communicating axial bore and a radial bore. The radial bore is used to output oil received by the axial bore to the bearing of the planetary shaft for lubrication. The planet carrier of one planetary gear set is spaced from the inner wall of the reducer housing. The space between the planet carrier of one planetary gear set and the inner wall of the reducer housing is used to transfer oil output from the radial bore of the planet carrier of one planetary gear set to the axial bore of the planetary shaft of the other planetary gear set.

11. The powertrain according to claim 10, characterized in that, The reducer housing includes a first housing and a second housing, the first housing enclosing the second housing, the first housing including a groove, the opening of the groove facing the second housing, wherein: The groove wall is used to fix the gear ring of the planetary gear set. The planet carrier of the planetary gear set is spaced apart from the groove wall. The gap between the planet carrier of the planetary gear set and the groove wall is used to transfer the oil output from the radial hole of the planet carrier of the planetary gear set to the axial hole of the planet shaft of the other planetary gear set.

12. The powertrain according to claim 11, characterized in that, The inner diameter of the gear ring of the other planetary gear set is larger than the inner diameter of the gear ring of the first planetary gear set, and the opening of the axial hole of the planet shaft of the other planetary gear set is directed toward the distance between the planet carrier of the first planetary gear set and the groove wall of the groove.

13. The powertrain according to claim 11, characterized in that, One end of the motor shaft extends into the groove, and the one end of the motor shaft serves as the sun gear of the first-stage planetary gear set. The one end of the motor shaft includes a motor shaft oil hole. The groove is also used to accommodate a thrust needle roller bearing and an oil collecting baffle. The thrust needle roller bearing is used to rotatably connect the planet carrier of the first-stage planetary gear set and the first housing. The thrust needle roller bearing surrounds the outer periphery of the motor shaft oil hole. The clearance in the thrust needle roller bearing is used to transmit the oil output from the motor shaft oil hole to the opening of the planet shaft of the first-stage planetary gear set. The oil collecting baffle surrounds the outer periphery of the thrust needle roller bearing. The oil collecting baffle is used to cover the outer peripheral surface of the thrust needle roller bearing and the opening of the axial hole of the planetary shaft in the first-stage planetary gear set, and to connect the gap of the outer peripheral surface of the thrust needle roller bearing and the opening of the axial hole of the planetary shaft in the first-stage planetary gear set.

14. The powertrain according to claim 11, characterized in that, The planet carrier of the other planetary gear set includes a half-shaft hole and a sealing member. One opening of the half-shaft hole faces the first planetary gear set, and the other opening of the half-shaft hole is for passing through the second housing and for inserting the half-shaft of the wheel. The sealing member is used to seal the first opening of the half-shaft hole and the central hole of the planet carrier for rotatable connection to the first planetary gear set, wherein: The sealing element includes a thrust bearing groove and a positioning groove. The thrust bearing groove is used to accommodate a thrust bearing, which is used to rotatably connect the sun gear of the other planetary gear set to the sealing element. Along the axial direction of the powertrain, the opening of the positioning groove is opposite to one of the planetary gear sets. The positioning groove is used to accommodate a portion of the half-shaft and restrict the half-shaft from moving radially along the powertrain. The inner diameter of the positioning groove is smaller than the inner diameter of the half-shaft hole. The thrust bearing groove surrounds the outer periphery of the positioning groove. Along the radial direction of the powertrain, the projection of the positioning groove and the thrust bearing groove at least partially overlap.

15. An electric vehicle, characterized in that, The electric vehicle includes a frame and a powertrain as described in any one of claims 1-14, the frame being used to secure the powertrain, and the drive motor of the powertrain being used to receive power from a power battery to drive the wheels via the planetary reducer.

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