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CN-121993570-A - Planetary reducer, power assembly and electric vehicle

CN121993570ACN 121993570 ACN121993570 ACN 121993570ACN-121993570-A

Abstract

The application provides a planetary reducer, a power assembly and an electric vehicle, and relates to the technical field of electric vehicles. The planetary reducer is respectively connected with wheels of the electric vehicle in a transmission way through the first half shaft and the second half shaft. The planetary reducer comprises a first planetary row, a second planetary row, a first locking structure and a second locking structure. The first half shaft is used for receiving power transmitted by the first planet row, and the second half shaft is used for receiving power transmitted by the second planet row. The first and second planet rows may differentially rotate the first and second axle shafts. The first locking structure is used for fixedly connecting the first half shaft, and the second locking structure is used for driving and connecting the second half shaft. When the first locking structure and the second locking structure are coupled, the first locking structure and the second locking structure are used for connecting the first half shaft and the second half shaft in a transmission mode. The application can realize the locking of the differential function of the planetary reducer by utilizing the first locking structure and the second locking structure, and reduce the risk that the electric vehicle cannot run on a bad road surface.

Inventors

  • HIDEYUKI INOUE

Assignees

  • 华为技术有限公司

Dates

Publication Date
20260508
Application Date
20260203

Claims (15)

  1. 1. A planetary reducer, characterized in that the planetary reducer is used for being respectively connected with wheels of an electric vehicle in a transmission way through a first half shaft and a second half shaft, the planetary reducer comprises a plurality of planetary rows, a first locking structure and a second locking structure, each planetary row comprises a sun gear, a planetary wheel, a planetary carrier and a gear ring, the planetary wheel is used for being connected with the outer peripheral surface of the sun gear and the inner peripheral surface of the gear ring in the transmission way, and the planetary carrier is used for being connected with the planetary wheel in the transmission way; The plurality of planet rows includes a first planet row and a second planet row, the ring gear of the first planet row is used for receiving power, the sun gear of the first planet row is used for driving the sun gear connected with the second planet row, the first half shaft is used for receiving power transmitted by the planet carrier of the first planet row, and the second half shaft is used for receiving power transmitted by the ring gear of the second planet row, wherein: The first locking structure is used for being fixedly connected with the first half shaft, the second locking structure is used for being in transmission connection with the second half shaft, and when the first locking structure is coupled with the second locking structure, the first locking structure is used for being in transmission connection with the first half shaft and the second half shaft.
  2. 2. The planetary reducer according to claim 1, wherein a first section of the first half shaft extends through the sun gear of the first planetary row into the sun gear of the second planetary row in an axial direction of the planetary reducer, a gap between the first section of the first half shaft and the sun gear of the second planetary row is for accommodating a first portion of the first locking structure, and an outer peripheral surface of the first section of the first half shaft is for fixedly connecting an inner peripheral surface of the first portion of the first locking structure.
  3. 3. The planetary reducer of claim 2, wherein the planet carrier of the first planet row extends into a gap between the sun gear of the first planet row and the first section of the first axle shaft, an outer peripheral surface of the first section of the first axle shaft for fixedly connecting an inner peripheral surface of the planet carrier of the first planet row, the first portion of the first locking structure being spaced from the planet carrier of the first planet row, wherein: The length of the sun gear extending into the second planetary row along the first section of the first half shaft in the axial direction of the planetary reducer is greater than the length of the first portion of the first locking structure.
  4. 4. A planetary reducer according to claim 2 or 3, characterized in that the second section of the first half-shaft is adjacent to the first section of the first half-shaft, which is distributed on the side of the first row of planets facing away from the second row of planets, the outer diameter of the first section of the first half-shaft being smaller than the outer diameter of the second section of the first half-shaft in the radial direction of the planetary reducer.
  5. 5. The planetary reducer of claim 4, wherein the first axle includes a through bore extending through the second section of the first axle, the through bore for communicating with an axle cavity of the second section of the first axle.
  6. 6. The planetary reducer according to any one of claims 1-5, wherein the ring gear of the second planetary row is configured to be in driving connection with the second half shaft via an output disc, the output disc being distributed between the ring gear and the second half shaft in a radial direction of the planetary reducer, and the second locking structure is configured to be in driving connection with the second half shaft via the output disc.
  7. 7. The planetary reducer of claim 6, wherein the second portion of the first locking structure protrudes from the sun gear of the second planetary row, the output disc comprises a groove, the groove faces away from the second planetary row in the axial direction of the planetary reducer, the groove is used for accommodating the second portion of the first locking structure and the second locking structure, the second half shaft protrudes into the groove through the bottom of the groove, and the second locking structure surrounds the outer peripheral side of the second half shaft.
  8. 8. The planetary reducer of claim 7, wherein an inner diameter of the groove in a radial direction of the planetary reducer is smaller than an outer diameter of the ring gear of the second planetary row.
  9. 9. The planetary reducer according to any one of claims 6-8, wherein the first locking structure includes a first opening and a second opening, the first opening being oriented toward the first row of planets in an axial direction of the planetary reducer, the first opening being for fixedly connecting a portion of the first half shaft, wherein: the second opening faces the second locking structure along the axial direction of the planetary reducer, the inner diameter of the second opening is larger than that of the first opening, and the second opening is used for accommodating part of the second half shaft.
  10. 10. The planetary reducer according to any one of claims 6 to 9, wherein the second locking structure comprises a protrusion protruding from a surface of the second locking structure facing the output disc, the output disc comprises a mounting hole, and the output disc is used for being in driving connection with the second locking structure by abutting the protrusion through a hole wall of the mounting hole, wherein: the length of the mounting hole is larger than the length of the protrusion along the circumferential direction of the planetary reducer, and the length of the mounting hole is larger than the length of the protrusion along the radial direction of the planetary reducer.
  11. 11. The planetary reducer of claim 10, wherein the second locking structure comprises a gear tooth distributed on an end face of the second locking structure facing the first locking structure along an axial direction of the planetary reducer, the second locking structure being configured to be drivingly connected to the first locking structure through the gear tooth, wherein: The pressure angle of the bulge is larger than that of the transmission gear.
  12. 12. The planetary reducer according to any one of claims 1-11, wherein the planetary reducer comprises an actuator for receiving electric power to drive the second locking structure to be coupled with the first locking structure, the housing of the planetary reducer comprises a receiving groove, a notch of the receiving groove faces the first planetary row along an axial direction of the planetary reducer, and the second half shaft extends into the receiving groove through a bottom of the receiving groove; the distance between the groove wall of the accommodating groove and the second locking structure along the radial direction of the planetary reducer is smaller than the distance between the groove wall of the accommodating groove and the second half shaft, the groove bottom of the accommodating groove is spaced from the first planetary row and the second planetary row, the space between the groove wall of the accommodating groove and the second locking structure is used for accommodating the actuator, and the actuator is fixedly connected to the groove wall and the groove bottom of the accommodating groove.
  13. 13. The planetary reducer of claim 12, wherein the actuator is an electromagnetic actuator, the actuator comprises an electromagnetic coil, and the material of the receiving groove is a non-magnetic metal.
  14. 14. A powertrain comprising a drive motor and a planetary reducer according to any one of claims 1-13, wherein the first half shaft passes through a motor shaft of the drive motor, the plurality of planetary rows of the planetary reducer further comprising a third planetary row, the sun gear of the third planetary row being distributed on an outer peripheral surface of the motor shaft, the planet carrier of the third planetary row being for driving the ring gear of the first planetary row.
  15. 15. An electric vehicle comprising a power cell and a powertrain as claimed in claim 14 for receiving power from the power cell and for driving wheels of the electric vehicle, or The electric vehicle comprising a power battery and a planetary reducer according to any one of claims 1-13 for driving connection of wheels of the electric vehicle.

Description

Planetary reducer, power assembly and electric vehicle Technical Field The application relates to the technical field of electric vehicles, in particular to a planetary reducer, a power assembly and an electric vehicle. Background In a powertrain of a vehicle, a speed reducer is used to reduce the rotational speed of power output from a drive motor and increase output torque. The differential mechanism is usually matched with the speed reducer for use, and under the scenes of turning of a vehicle and the like, the differential mechanism can realize different rotation speeds of the wheels at the left side and the right side, so that the vehicle can stably run. However, when the vehicle is traveling on a poor road surface, if one side wheel slips, it is difficult for the differential to efficiently transmit power to the other side wheel with relatively greater adhesion, resulting in failure of the vehicle to get stuck. Disclosure of Invention The embodiment of the application provides a planetary reducer with a locking differential function, a power assembly and an electric vehicle. In a first aspect, an embodiment of the present application provides a planetary reducer for driving connection to wheels of an electric vehicle via a first half shaft and a second half shaft, respectively. The planetary reducer comprises a plurality of planetary rows, a first locking structure and a second locking structure. Each planet row comprises a sun gear, a planet wheel, a planet carrier and a gear ring, wherein the planet wheel is used for connecting the outer peripheral surface of the sun gear and the inner peripheral surface of the gear ring in a transmission mode, and the planet carrier is used for connecting the planet wheel in a transmission mode. The plurality of planet rows includes a first planet row and a second planet row. The ring gear of the first planetary gear set is used for receiving power, and the sun gear of the first planetary gear set is used for being in transmission connection with the sun gear of the second planetary gear set. The first half shaft is used for receiving power transmitted by the planet carrier of the first planet row, and the second half shaft is used for receiving power transmitted by the gear ring of the second planet row. The first locking structure is used for fixedly connecting with the first half shaft, and the second locking structure is used for driving and connecting with the second half shaft. When the first locking structure and the second locking structure are coupled, the first locking structure and the second locking structure are used for connecting the first half shaft and the second half shaft in a transmission mode. In an embodiment of the application, the planetary reducer may differentially rotate the first and second axle shafts. Specifically, the power received by the ring gear of the first row of planets has two transmission paths. In the first transmission path, the ring gear of the first planetary gear set transmits power to the first half shaft via the planetary gears of the first planetary gear set and the carrier of the first planetary gear set. In the second transmission path, the gear ring of the first planetary gear set transmits power to the sun gear of the second planetary gear set through the planet gears of the first planetary gear set and the sun gear of the first planetary gear set, and finally the gear ring of the second planetary gear set drives the second half shaft. The first transmission path shows that the sun gear of the first planetary gear set, the planet gears of the first planetary gear set, the planet carrier of the first planetary gear set and the ring gear of the first planetary gear set can all be in a rotating state. In the process of turning of the vehicle, the resistance received by the wheels on the two sides which are respectively connected with the first half shaft and the second half shaft in a transmission way is different, and the planetary reducer can distribute more power to the wheel on the side with smaller resistance by adjusting the rotation state of the planetary gear so as to meet the requirement of turning of the vehicle on the rotation speeds of the wheels on different sides. In the embodiment of the application, the planetary reducer integrates the functions of speed reduction and differential speed. Compared with a scheme of utilizing an independent differential mechanism to be matched with a speed reducer, the planetary speed reducer disclosed by the embodiment of the application has higher integration level, is beneficial to reducing the number of parts and shortening the power transmission path. However, the differential function of planetary reducers can cause difficulty in driving the vehicle in certain special scenarios. When the vehicle is traveling on a bad road such as ice and snow, mud, etc., the wheels are likely to slip. Assuming that one side wheel slips, the other side wheel has a large adhesion to