Coaxial reducer, electric drive assembly and vehicle

Abstract

This utility model discloses a coaxial reducer, an electric drive assembly, and a vehicle. The coaxial reducer includes a first output shaft and a two-stage planetary transmission output structure. The first output shaft includes a shaft body and a connecting portion disposed on one side of the shaft body. The two-stage planetary transmission output structure includes a first-stage planetary gear set, which includes a first planet carrier and a first planetary gear rotatably mounted on the first planet carrier. The first planet carrier is drivenly connected to the connecting portion, and an installation space for accommodating a hollow motor shaft is formed between the first planet carrier and the shaft body. The first planetary gear extends at least partially into the installation space. This utility model features high space utilization, high torque density, and low vibration and noise.

Description

Technical Field

[0001] This utility model relates to vehicle drive systems, specifically to a coaxial reducer, an electric drive assembly, and a vehicle. Background Technology

[0002] As a core component of the electric drive system of new energy vehicles, the electric vehicle reducer currently generally adopts... Figure 1 The parallel-shaft reducer 10 shown inputs torque through an input shaft assembly 101 connected to a motor via a spline, and transmits power to a differential assembly 103 via an intermediate shaft assembly 102. The gears on the input shaft assembly 101, intermediate shaft assembly 102, and differential assembly 103 of the parallel-shaft reducer 10 form a speed ratio, achieving the function of speed reduction and torque increase. Because the gears of the three components of the parallel-shaft reducer 10 are arranged in parallel, its Y-axis dimension is relatively large (Y-axis refers to the direction perpendicular to the gear line), resulting in low space utilization and low torque density. Utility Model Content

[0003] In view of this, the purpose of this utility model is to provide a coaxial reducer, electric drive assembly and vehicle, which has high space utilization, high torque density and low vibration and noise.

[0004] This utility model discloses a coaxial reducer, including a first output shaft and a two-stage planetary transmission output structure. The first output shaft includes a shaft body and a connecting portion disposed on one side of the shaft body. The two-stage planetary transmission output structure includes a first-stage planetary gear assembly, which includes a first planet carrier and a first planetary gear rotatably disposed on the first planet carrier. The first planet carrier is drivenly connected to the connecting portion, and an installation space for accommodating a hollow motor shaft is formed between the first planet carrier and the shaft body. The first planetary gear extends at least partially into the installation space.

[0005] Furthermore, the two-stage planetary transmission output structure also includes a ring gear assembly, a second-stage planetary carrier assembly, and a housing assembly; the ring gear assembly includes a first ring gear and a second sun gear connected to the first ring gear; the second-stage planetary carrier assembly includes a second planetary carrier and a second planetary gear rotatably mounted on the second planetary carrier; the housing assembly includes a reducer housing, a second output shaft rotatably mounted on the reducer housing, and a second ring gear drively connected to the second output shaft; the first planetary gear meshes with the first ring gear, and the second sun gear and the second ring gear mesh with the planetary gear respectively.

[0006] Furthermore, the first planetary carrier includes a first main frame and a connecting cylinder. The connecting cylinder is disposed on the side of the first main frame facing closer to the housing assembly, and the connecting cylinder is connected to the connecting part by a key.

[0007] Furthermore, the first-stage planetary gear assembly also includes a first planetary pin, a first bearing, and a first bearing end washer. The first planetary pin is fixedly connected to the first main frame. The inner ring of the first bearing and the first bearing end washer are both sleeved on the first planetary pin, and the first planetary gear is sleeved on the outer ring of the first bearing.

[0008] Furthermore, the second sun gear is provided with a plurality of first engagement teeth extending radially outward, and a first groove is formed between two adjacent first engagement teeth; the first gear ring is provided with a plurality of first engagement hooks extending toward the side close to the housing assembly, and each of the plurality of first engagement hooks includes a first circumferential limiting part and a first axial limiting part connected as one piece, the first circumferential limiting part is inserted into the first groove, and a first limiting ring is provided between the first axial limiting part and the first engagement tooth.

[0009] Furthermore, an axial limiting plate is provided inside the second sun gear, and an adjusting shim and a thrust bearing are provided on one side of the first planetary carrier.

[0010] Furthermore, the second planetary carrier includes a second main carrier body and a connecting ring platform. The connecting ring platform is disposed on the side of the second main carrier body facing away from the housing assembly. The second main carrier body extends into the reducer housing. The reducer housing is provided with a first circumferential limiting tooth. The connecting ring platform is provided with a second circumferential limiting tooth that meshes with the first circumferential limiting tooth. A sealing ring and an elastic axial limiting retaining ring are provided between the connecting ring platform and the housing assembly.

[0011] Furthermore, the second-stage planetary carrier assembly also includes a second planetary pin, a second bearing, and a second bearing end washer. The second planetary pin is fixedly connected to the second main carrier body. The inner ring of the second bearing is sleeved on the second planetary pin. The second planetary gear is sleeved on the outer ring of the second bearing. The second bearing end washer is disposed between the second bearing and the second main carrier body.

[0012] Furthermore, the second output shaft is provided with a plurality of second engagement teeth extending radially outward, and a second groove is formed between two adjacent second engagement teeth; the second gear ring is provided with a plurality of second engagement hooks extending toward the side close to the housing assembly, and each of the plurality of second engagement hooks includes a second circumferential limiting part and a second axial limiting part connected as one piece, the second circumferential limiting part is inserted into the second groove, and a second limiting ring is provided between the second axial limiting part and the second engagement teeth.

[0013] An electric drive assembly according to this utility model includes an electric drive housing, a motor, and the aforementioned coaxial reducer. The electric drive housing and the reducer housing are both provided with openings on their opposite sides and are joined together to form a closed cavity. The motor and the coaxial reducer are disposed in the closed cavity. The hollow shaft of the motor is sleeved on the shaft body. A first sun gear is provided on the hollow shaft of the motor. The first sun gear extends into the mounting space and meshes with the first planetary gear.

[0014] One type of vehicle according to this utility model includes the above-mentioned electric drive assembly.

[0015] The beneficial effects of this utility model are: the coaxial reducer of this utility model can divert the power input from the outside and can also reduce the power and increase the torque, forming a coaxial reducer with "one input and two outputs". The axial and radial dimensions are small, the space utilization rate is high, the torque density is high, and the coaxial reducer uses planetary gears to balance the load, with a large number of meshing teeth and low vibration and noise. Attached Figure Description

[0016] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the following drawings are provided for illustration: Figure 1 This is an exploded structural diagram of a parallel shaft reducer in the prior art. Figure 2 This is an exploded structural diagram of the coaxial reducer of this utility model; Figure 3 This is an exploded structural diagram of the first-stage planetary set assembly of this utility model; Figure 4 This is an exploded structural diagram of the gear ring assembly of this utility model; Figure 5 This is a schematic diagram of the gear ring assembly of this utility model; Figure 6 This is an exploded structural diagram of the second-stage planetary carrier assembly of this utility model; Figure 7 This is an exploded structural diagram of the shell assembly of this utility model; Figure 8 This is a schematic diagram of the electric drive assembly of this utility model.

[0017] The following labels are shown in the attached diagram: 1-First output shaft, 11-Shaft body, 12-Connecting part, 13-First oil seal; 2-First-stage planetary gear assembly, 21-First planetary carrier, 211-First main frame, 212-Connecting cylinder, 22-First planetary gear, 23-First planetary pin, 24-First bearing, 25-First bearing end washer, 26-Adjusting shim, 27-Thrust bearing; 3-Gear ring assembly, 31-First gear ring, 311-First engagement hook, 32-Second sun gear, 321-First engagement tooth, 33-First limiting ring, 34-Axial limiting plate; 4-Second-stage planetary carrier assembly, 41-Second planetary carrier, 411-Second main carrier body, 412-Connecting ring platform, 42-Second planetary gear, 43-Second planetary pin, 44-Second bearing, 45-Second bearing end washer; 5-Housing assembly, 51-Reducer housing, 52-Second output shaft, 521-Second engagement tooth, 53-Second gear ring, 531-Second engagement hook, 54-Second limiting ring, 55-Second oil seal, 56-Output shaft bearing, 57-Bearing retainer; 6-Sealing ring; 7-Elastic axial retaining ring; 8-Electric drive housing; 9-Motor, 91-Hollow shaft of motor, 92-First sun gear, 93-Motor housing; 10-Parallel shaft reducer, 101-Input shaft assembly, 102-Intermediate shaft assembly, 103-Differential assembly. Detailed Implementation

[0018] The technical solution of this utility model will be described in detail below with reference to the accompanying drawings and embodiments.

[0019] like Figures 2-8 As shown, a coaxial reducer in this embodiment includes a first output shaft 1 and a two-stage planetary transmission output structure. The first output shaft 1 includes a shaft body 11 and a connecting portion 12 disposed on one side of the shaft body 11. The two-stage planetary transmission output structure includes a first-stage planetary gear assembly 2. The first-stage planetary gear assembly 2 includes a first planet carrier 21 and a first planetary gear 22 rotatably disposed on the first planet carrier 21. The first planet carrier 21 is connected to the connecting portion 12 in a transmission manner. An installation space for accommodating a hollow shaft 91 of a motor is formed between the first planet carrier 21 and the shaft body 11. The first planetary gear 22 extends at least partially into the installation space.

[0020] The two-stage planetary transmission output structure of the coaxial reducer can output power through the second output shaft 52, and the first output shaft 1 of the coaxial reducer can also output power. These are connected to the half-shafts respectively to transmit power to the left and right wheels of the vehicle, achieving power output to the left and right sides. The coaxial reducer is used to connect to the motor 9. The hollow shaft 91 of the motor 9 is sleeved on the shaft body 11. A first sun gear 92 is provided on the hollow shaft 91, extending into the installation space and meshing with the first planetary gear 22. The motor 9 outputs power through the hollow shaft 91. The hollow shaft 91 transmits the power to the first-stage planetary gear assembly 2 through the first sun gear 92. The first-stage planetary gear assembly 2 then distributes the power to the first output shaft 1 and the two-stage planetary transmission output structure. Since the central axes of the hollow shaft 91, the first output shaft 1, and the two-stage planetary transmission output structure all coincide, a coaxial reducer with "one input and two outputs" is formed. The axial and radial dimensions are small, the space utilization is high, and the torque density is high. Furthermore, the coaxial reducer balances the load through the planetary gears, has a large number of meshing teeth, and has low vibration and noise.

[0021] In this embodiment, the two-stage planetary transmission output structure further includes a ring gear assembly 3, a second-stage planetary carrier assembly 4, and a housing assembly 5. The ring gear assembly 3 includes a first ring gear 31 and a second sun gear 32 connected to the first ring gear 31. The second-stage planetary carrier assembly 4 includes a second planetary carrier 41 and a second planetary gear 42 rotatably mounted on the second planetary carrier 41. The housing assembly 5 includes a reducer housing 51, a second output shaft 52 rotatably mounted on the reducer housing 51, and a second ring gear 53 pulverically connected to the second output shaft 52. The first planetary gear 22 meshes with the first ring gear 31, and the second sun gear 32 and the second ring gear 53 mesh with the planetary gears respectively. There are multiple first planetary gears 22 and multiple second planetary gears 42, for example, four first planetary gears 22 and eight second planetary gears 42, or any other number of first planetary gears 22 and second planetary gears 42.

[0022] A coaxial reducer is used to connect to a motor 9. The hollow shaft 91 of the motor 9 is sleeved on the shaft body 11. A first sun gear 92 is provided on the hollow shaft 91. The first sun gear 92 extends into the installation space and meshes with the first planetary gear 22. The motor 9 outputs power through the hollow shaft 91. The first planetary gear 22 is rotatably mounted on the first planetary carrier 21 and meshes with the first ring gear 31. The first planetary gear 22 can rotate on its own axis and revolve around the axis of the first planetary carrier 21. Therefore, after the power is transmitted from the first sun gear 92 of the hollow shaft 91 to the first planetary gear 22, the power can be split to the first ring gear 31 and the first planetary carrier 21. The first planetary gear 22 revolves and transmits the power through the first planetary carrier 21 to the first output shaft 1 and then to the right wheel of the vehicle. The first planetary gear 22 rotates and transmits the power through the first ring gear 31 to the second sun gear 32. Furthermore, since the second sun gear 32 is rotatably mounted on the second planetary carrier 41, and the second planetary gear 42 meshes with the second ring gear 53, the second planetary gear 42 can rotate within the second planetary carrier 41. The second planetary carrier 41 is fixed to the reducer housing 51, preventing the second planetary gear 42 from revolving around its axis. Therefore, the power diverted to the second sun gear 32 can drive the second planetary gear 42 to rotate, which in turn drives the second output shaft 52 to rotate via the second ring gear 53, thus transmitting power to the left wheel of the vehicle. The first output shaft 1 and the second output shaft 52 rotate in the same direction, and both achieve power reduction and torque increase through planetary gear reduction. Because the central axes of the hollow shaft 91 of the motor, the first output shaft 1, and the second output shaft 52 all coincide, a coaxial reducer with "one input and two outputs" is formed. This results in smaller axial and radial dimensions, higher space utilization, and higher torque density. Moreover, the coaxial reducer balances the load through planetary gears, has a large number of meshing teeth, and exhibits lower vibration and noise.

[0023] When the vehicle turns right, the right wheel feeds back to the first planetary carrier 21 of the first-stage planetary gear set 2, which reduces the rotational speed of the first planetary gear 22, causing the rotational speed of the first planetary gear 22 to decrease, and the rotational speed of the first ring gear 31 assembly 3 to increase, thus achieving differential speed. The same applies when the vehicle turns left, the rotational speed of the first planetary carrier 21 of the first-stage planetary gear set 2 increases, and the rotational speed of the first ring gear 31 assembly 3 decreases, thus achieving differential speed.

[0024] In this embodiment, the first planetary carrier 21 includes a first main frame 211 and a connecting cylinder 212. The connecting cylinder 212 is disposed on the side of the first main frame 211 facing closer to the housing assembly 5. The connecting cylinder 212 is connected to the connecting part 12 by a key.

[0025] Specifically, the connecting cylinder 212 is located on the left side of the first main frame 211, and the connecting cylinder 212 is connected to the connecting part 12 via a spline. Correspondingly, the connecting part 12 is located on the left side of the shaft body 11. An installation space is formed between the first main frame 211 and the main shaft body. A coaxial reducer is used to connect to the motor 9. The hollow shaft 91 of the motor 9 is sleeved on the shaft body 11. A first sun gear 92 is provided on the hollow shaft 91. The first sun gear 92 extends into the installation space and meshes with the first planetary gear 22.

[0026] In this embodiment, the first-stage planetary gear assembly 2 further includes a first planetary pin 23, a first bearing 24, and a first bearing end washer 25. The first planetary pin 23 is fixedly connected to the first main frame 211. The inner ring of the first bearing 24 and the first bearing end washer 25 are both sleeved on the first planetary pin 23. The first planetary gear 22 is sleeved on the outer ring of the first bearing 24.

[0027] The first planetary pin 23 and the first bearing 24 ensure that the first planetary gear 22 can rotate on the first main frame 211. The first bearing end washer 25 is located between the first bearing 24 and the first main frame 211 to reduce the wear and movement of the first bearing 24.

[0028] In this embodiment, the second sun gear 32 is provided with a plurality of first engagement teeth 321 extending radially outward, and a first groove is formed between two adjacent first engagement teeth 321; the first gear ring 31 is provided with a plurality of first engagement hooks 311 extending toward the side close to the housing assembly 5, and each of the plurality of first engagement hooks 311 includes a first circumferential limiting part and a first axial limiting part connected as one piece, the first circumferential limiting part is inserted into the first groove, and a first limiting ring 33 is provided between the first axial limiting part and the first engagement teeth 321.

[0029] The first circumferential limiting part is inserted into the first groove to achieve circumferential limiting, so that the second sun gear 32 and the first gear ring 31 can rotate synchronously.

[0030] By setting a first limiting ring 33 between the first axial limiting part and the first engaging tooth 321, the axial limiting of the two is achieved, so that the second sun gear 32 and the first gear ring 31 are relatively fixed in the axial direction.

[0031] In this embodiment, an axial limiting plate 34 is provided inside the second sun gear 32, and an adjusting shim 26 and a thrust bearing 27 are provided on one side of the first planetary carrier 21.

[0032] The second sun gear 32 and the first gear 31 of the gear ring assembly 3 are connected by the structure of the first engaging tooth 321, the first engaging hook 311 and the first limiting ring 33, and respectively mesh with the gears on both sides to offset most of the axial force of the gear ring assembly 3. The remaining axial force is offset by the axial limiting plate 34 cooperating with the first stage planetary gear assembly 2 and the first output shaft 1 to ensure the axial limiting of the gear ring assembly 3.

[0033] The right side of the first output shaft 1 is rotatably engaged with the electric drive housing 8 via a bearing and a first oil seal 13. The left side of the first output shaft 1 is connected to the connecting cylinder 212 of the first planetary carrier 21 via a connecting part 12. An adjusting shim 26 and a thrust bearing 27 are provided on the side of the first planetary carrier 21 facing the motor 9. The axial positioning of the first planetary carrier 21 is achieved by the adjusting shim 26 and the thrust bearing 27 abutting against each other between the first planetary carrier 21 and the motor housing 93.

[0034] In this embodiment, the second planetary carrier 41 includes a second main carrier body 411 and a connecting ring platform 412. The connecting ring platform 412 is disposed on the side of the second main carrier body 411 facing away from the housing assembly 5. The second main carrier body 411 extends into the reducer housing 51. The reducer housing 51 is provided with a first circumferential limiting tooth. The connecting ring platform 412 is provided with a second circumferential limiting tooth that meshes with the first circumferential limiting tooth. A sealing ring 6 and an elastic axial limiting retaining ring 7 are provided between the connecting ring platform 412 and the housing assembly 5.

[0035] The first circumferential limiting tooth meshes with the second circumferential limiting tooth, preventing the second planetary carrier 41 from rotating relative to the reducer housing 51, thus fixing the second planetary carrier 41 in the circumferential direction. After being compressed, the elastic axial limiting ring 7 is sleeved on the connecting ring platform 412 and extends into the reducer housing 51. After moving to the position of the corresponding annular groove in the reducer housing 51, the elastic axial limiting ring 7 springs back and locks onto the reducer housing 51, preventing the second planetary carrier 41 from moving axially relative to the reducer housing 51, thus fixing the second planetary carrier 41 in the axial direction.

[0036] The sealing ring 6 is used to ensure the sealing performance between the connecting ring platform 412 and the housing assembly 5.

[0037] In this embodiment, the second-stage planetary carrier assembly 4 further includes a second planetary pin 43, a second bearing 44, and a second bearing end washer 45. The second planetary pin 43 is fixedly connected to the second main carrier body 411. The inner ring of the second bearing 44 is sleeved on the second planetary pin 43. The second planetary gear 42 is sleeved on the outer ring of the second bearing 44. The second bearing end washer 45 is disposed between the second bearing 44 and the second main carrier body 411.

[0038] The second planetary pin 43 and the second bearing 44 ensure that the second planetary gear 42 can rotate on the second main frame 411. The second bearing end washer 45 is located between the second bearing 44 and the second main frame 411 to reduce the wear and movement of the second bearing 44.

[0039] In this embodiment, the second output shaft 52 is provided with a plurality of second engaging teeth 521 extending radially outward, and a second groove is formed between two adjacent second engaging teeth 521; the second gear ring 53 is provided with a plurality of second engaging hooks 531 extending toward the side close to the housing assembly 5, and each of the plurality of second engaging hooks 531 includes a second circumferential limiting part and a second axial limiting part connected as one piece, the second circumferential limiting part is inserted into the second groove, and a second limiting ring 54 is provided between the second axial limiting part and the second engaging teeth 521.

[0040] The second circumferential limiting part is inserted into the second groove to achieve circumferential limiting, so that the second output shaft 52 and the second gear ring 53 can rotate synchronously.

[0041] A second limiting ring 54 is provided between the second axial limiting part and the second engaging tooth 521 to achieve axial limiting, so that the second output shaft 52 and the second gear ring 53 are relatively fixed in axial direction.

[0042] The second output shaft 52 is further provided with a second oil seal 55, an output shaft bearing 56, a bearing retainer 57 and other structures between the second output shaft 52 and the reducer housing 51, which are used to realize the rotational fit and sealing between the second output shaft 52 and the reducer housing 51.

[0043] Example 2: like Figure 8 As shown, an electric drive assembly in this embodiment includes an electric drive housing 8, a motor 9, and the aforementioned coaxial reducer. The electric drive housing 8 and the reducer housing 51 both have openings on their opposite sides, and they are joined to form a closed cavity. The motor 9 and the coaxial reducer are disposed within the closed cavity. The hollow motor shaft 91 of the motor 9 is sleeved on the shaft body 11. A first sun gear 92 is disposed on the hollow motor shaft 91, extending into the mounting space and meshing with the first planetary gear 22. An adjusting shim 26 and a thrust bearing 27 are disposed on the side of the first planetary carrier 21 facing the motor 9. The axial positioning of the first planetary carrier 21 is achieved by the adjusting shim 26 and the thrust bearing 27 abutting against each other between the first planetary carrier 21 and the motor housing 93. Preferably, the hollow motor shaft 91 and the first sun gear 92 are integrally formed.

[0044] Example 3: One vehicle in this embodiment includes the aforementioned electric drive assembly. The vehicle can be, but is not limited to, a pure electric vehicle (PEV / BEV), a hybrid electric vehicle (HEV), a range-extended electric vehicle (REEV), a plug-in hybrid electric vehicle (PHEV), or a new energy vehicle.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A coaxial reducer characterized by: The device includes a first output shaft (1) and a two-stage planetary transmission output structure. The first output shaft (1) includes a shaft body (11) and a connecting part (12) disposed on one side of the shaft body (11). The two-stage planetary transmission output structure includes a first-stage planetary gear assembly (2). The first-stage planetary gear assembly (2) includes a first planet carrier (21) and a first planetary gear (22) rotatably disposed on the first planet carrier (21). The first planet carrier (21) is connected to the connecting part (12) in a transmission manner. An installation space for accommodating the hollow shaft (91) of the motor is formed between the first planet carrier (21) and the shaft body (11). The first planetary gear (22) extends at least partially into the installation space.

2. The in-line speed reducer of claim 1, wherein: The two-stage planetary transmission output structure further includes a gear ring assembly (3), a second-stage planetary carrier assembly (4), and a housing assembly (5); the gear ring assembly (3) includes a first gear ring (31) and a second sun gear (32) connected to the first gear ring (31); the second-stage planetary carrier assembly (4) includes a second planetary carrier (41) and a second planetary gear (42) rotatably mounted on the second planetary carrier (41); the housing assembly (5) includes a reducer housing (51), a second output shaft (52) rotatably mounted on the reducer housing (51), and a second gear ring (53) pulverically connected to the second output shaft (52); the first planetary gear (22) meshes with the first gear ring (31), and the second sun gear (32) and the second gear ring (53) mesh with the planetary gear respectively.

3. The in-line speed reducer of claim 2, wherein: The first planetary carrier (21) includes a first main frame body (211) and a connecting tube (212). The connecting tube (212) is disposed on the side of the first main frame body (211) facing closer to the housing assembly (5). The connecting tube (212) is connected to the connecting part (12) by a key.

4. The in-line speed reducer of claim 3, wherein: The first-stage planetary gear assembly (2) also includes a first planetary pin (23), a first bearing (24) and a first bearing end washer (25). The first planetary pin (23) is fixedly connected to the first main frame (211). The inner ring of the first bearing (24) and the first bearing end washer (25) are both sleeved on the first planetary pin (23). The first planetary gear (22) is sleeved on the outer ring of the first bearing (24).

5. The in-line speed reducer of claim 2, wherein: The second sun gear (32) is provided with a plurality of first engagement teeth (321) extending radially outward, and a first groove is formed between two adjacent first engagement teeth (321); the first gear ring (31) is provided with a plurality of first engagement hooks (311) extending toward the side close to the housing assembly (5), and each of the plurality of first engagement hooks (311) includes a first circumferential limiting part and a first axial limiting part connected as one piece, the first circumferential limiting part is inserted into the first groove, and a first limiting ring (33) is provided between the first axial limiting part and the first engagement tooth (321).

6. The in-line speed reducer of claim 2, wherein: The second sun gear (32) is provided with an axial limiting plate (34), and the first planet carrier (21) is provided with an adjusting shim (26) and a thrust bearing (27) on one side.

7. The in-line speed reducer of claim 2, wherein: The second planetary carrier (41) includes a second main carrier body (411) and a connecting ring platform (412). The connecting ring platform (412) is located on the side of the second main carrier body (411) facing away from the housing assembly (5). The second main carrier body (411) extends into the reducer housing (51). The reducer housing (51) is provided with a first circumferential limiting tooth. The connecting ring platform (412) is provided with a second circumferential limiting tooth that meshes with the first circumferential limiting tooth. A sealing ring (6) and an elastic axial limiting retaining ring (7) are provided between the connecting ring platform (412) and the housing assembly (5).

8. The in-line speed reducer of claim 7, wherein: The second-stage planetary carrier assembly (4) also includes a second planetary pin (43), a second bearing (44), and a second bearing end washer (45). The second planetary pin (43) is fixedly connected to the second main carrier body (411). The inner ring of the second bearing (44) is sleeved on the second planetary pin (43). The second planetary gear (42) is sleeved on the outer ring of the second bearing (44). The second bearing end washer (45) is disposed between the second bearing (44) and the second main carrier body (411). The second output shaft (52) is provided with a plurality of second engagement teeth (521) extending radially outward, and a second groove is formed between two adjacent second engagement teeth (521); the second gear ring (53) is provided with a plurality of second engagement hooks (531) extending toward the side close to the housing assembly (5), and each of the plurality of second engagement hooks (531) includes a second circumferential limiting part and a second axial limiting part connected as one piece, the second circumferential limiting part is inserted into the second groove, and a second limiting ring (54) is provided between the second axial limiting part and the second engagement teeth (521).

9. An electric drive assembly, characterized by: The device includes an electric drive housing (8), a motor (9), and a coaxial reducer as described in any one of claims 1-8. The electric drive housing (8) and the reducer housing (51) are provided with openings on their opposite sides and are joined together to form a closed cavity. The motor (9) and the coaxial reducer are disposed in the closed cavity. The hollow shaft (91) of the motor (9) is sleeved on the shaft body (11). A first sun gear (92) is provided on the hollow shaft (91). The first sun gear (92) extends into the mounting space and meshes with the first planetary gear (22).

10. A vehicle characterized by: Includes the electric drive assembly as described in claim 9.

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