Electric drive assembly and electric vehicle

Abstract

The electric drive assembly comprises a motor and a reduction gearbox, the motor comprises a shell and a rotor shaft, a rear end cover and a front end cover are arranged at the two ends of the shell respectively, and a transmission shaft hole coaxial with the rotor shaft is formed in the front end cover in a penetrating mode; the reduction gearbox comprises a reduction gearbox body integrally formed on the front end cover, the reduction gearbox body is located on the side, away from the shell, of the front end cover and matched with a gearbox cover, and an input shaft and an output shaft which are arranged in parallel are arranged between the reduction gearbox body and the gearbox cover. The input shaft and the rotor shaft are coaxially arranged, the end, facing the rotor shaft, of the input shaft penetrates through the transmission shaft hole, and an annular limiting part protruding inwards is arranged in the transmission shaft hole and abuts against the outer ring of the first bearing. The motor has the advantages of being compact in structural design, small in size, capable of avoiding axial stress of the motor shaft, beneficial to prolonging the service life of the motor, low in maintenance difficulty and the like.

Description

Technical Field

[0001] This utility model relates to the field of electric vehicle technology, and in particular to an electric drive assembly and an electric vehicle. Background Technology

[0002] In recent years, with the continuous development of electric vehicle technology, the integrated design of its electric drive assembly has become a future development trend. The electric drive assembly mainly consists of an electric motor and a gearbox. To make the structure of the electric motor and gearbox more compact, the input shaft of the gearbox is usually coaxially mounted on the output shaft of the electric motor; some gearboxes even use a coaxial design between the input shaft and the electric motor. Because helical gears mesh smoothly, have smoother tooth surface contact, and relatively less vibration and noise, helical gear transmission is often used in gearboxes to make transmission smoother. During helical gear transmission, axial thrust is generated, which can easily subject the coaxially mounted motor shaft to axial force, affecting the reliability and service life of the motor. Utility Model Content

[0003] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is: how to provide an electric drive assembly and electric vehicle with a compact structure that can avoid axial force on the motor shaft and help extend the service life of the motor.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] An electric drive assembly includes a motor and a gearbox. The motor includes a housing and a rotor shaft. A rear end cover and a front end cover are respectively provided at both ends of the housing. The gearbox includes a gearbox body integrally formed on the front end cover. The gearbox body is located on the side of the front end cover away from the housing and is fitted with a cover. An input shaft and an output shaft are arranged parallel to each other between the gearbox body and the cover. A reduction gear set is provided between the input shaft and the output shaft. A transmission shaft hole coaxial with the rotor shaft is provided through the front end cover. The input shaft is rotatably disposed in the transmission shaft hole through a first bearing and is coaxially connected to the rotor shaft. An annular limiting part protruding inward is provided in the transmission shaft hole. The annular limiting part is located on the side of the first bearing facing the housing and abuts against the outer ring of the first bearing. An annular step protruding outward is provided on the input shaft. The annular step is located on the side of the first bearing away from the housing and abuts against the inner ring of the first bearing.

[0006] In the above structure, since the annular limiting part is located on the side of the first bearing facing the housing and abuts against the outer ring of the first bearing on the input shaft, and the input shaft has an outwardly protruding annular step, which is located on the side of the first bearing away from the housing and abuts against the inner ring of the first bearing, the input shaft is always located inside the gearbox under the restriction of the annular step, the first bearing and the annular limiting part. The axial thrust borne by the input shaft is also ultimately applied to the annular limiting part, avoiding the rotor bearing from being subjected to a large axial force, which is beneficial to improving the reliability and service life of the motor.

[0007] Furthermore, the two ends of the rotor shaft are rotatably mounted on the rear end cover and the front end cover via bearings, and the end facing the drive shaft hole has a coaxially arranged spline hole; the end of the input shaft has a spline shaft that is inserted into the spline hole, and the length of the spline shaft is less than the depth of the spline hole.

[0008] In this way, since the length of the spline shaft on the input shaft is less than the depth of the spline hole on the rotor shaft, no axial thrust is generated between the input shaft and the rotor shaft, thereby avoiding axial force on the motor bearings and helping to extend the service life of the motor.

[0009] Furthermore, the drive shaft hole has a first retaining ring groove extending circumferentially, and the annular limiting part is a first retaining ring that fits into the first retaining ring groove.

[0010] Furthermore, the reduction gear set includes an input gear coaxially mounted on the input shaft and an output gear coaxially mounted on the output shaft, wherein the input gear and the output gear mesh with each other.

[0011] In electric motorcycles, especially off-road electric motorcycles, the repeated impacts from the motorcycle are applied to the output shaft of the electric drive assembly via the drive chain, causing tension on the housing and front cover of the electric drive assembly. Connecting the input and output shafts through direct-meshing input and output gears allows for a shorter center distance between the output shaft and the motor. Under the same tensile force, a shorter center distance results in a smaller bending moment acting on the housing and front cover, thereby significantly improving the overall strength of the electric drive assembly and extending its service life.

[0012] Furthermore, the input gear is integrally formed on the input shaft, and the output gear is integrally formed on the output shaft.

[0013] Furthermore, both ends of the input shaft are rotatably mounted on the gearbox body and cover via deep groove ball bearings; both ends of the output shaft are rotatably mounted on the gearbox body and cover via cylindrical roller bearings.

[0014] Furthermore, a first dynamic sealing assembly is provided between the input shaft and the transmission shaft hole, and the first dynamic sealing assembly is located on the side of the annular limiting portion facing the housing.

[0015] Furthermore, the cover has an output shaft hole coaxially arranged with the output shaft, and the output shaft is rotatably inserted through the output shaft hole via a second dynamic sealing assembly.

[0016] Furthermore, the output shaft hole has a second snap ring groove coaxially arranged and a second snap ring is fitted therein, and the second dynamic seal assembly is located on the side of the second snap ring facing outward.

[0017] An electric vehicle, comprising the electric drive assembly as described above.

[0018] In summary, this utility model has the advantages of compact structural design, avoiding axial force on the motor shaft, and extending the service life of the motor. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0020] Figure 2 This is a cross-sectional structural diagram of the present invention. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the embodiments.

[0022] In practical implementation: such as Figure 1 and Figure 2As shown, an electric drive assembly includes a motor 1 and a gearbox 2. The motor 1 includes a housing 11 and a rotor shaft 12. A rear end cover 13 and a front end cover 14 are respectively provided at both ends of the housing 11. The two ends of the rotor shaft 12 are rotatably mounted on the rear end cover 13 and the front end cover 14 via bearings. A drive shaft hole 15 coaxial with the rotor shaft 12 is provided through the front end cover 14. The gearbox 2 includes a gearbox body 21 integrally formed on the front end cover 14. The gearbox body 21 is located on the side of the front end cover 14 opposite to the housing 11 and is fitted with a cover 22. The gearbox body 21 and... An input shaft 23 and an output shaft 24 are arranged parallel to each other between the housing cover 22, and a reduction gear set is provided between the input shaft 23 and the output shaft 24. The end of the input shaft 23 facing the motor 1 is rotatably mounted on the transmission shaft hole 15 through a first bearing. The transmission shaft hole 15 has an inwardly protruding annular limiting part at a position away from the input shaft 23, and the outer ring of the first bearing abuts against the annular limiting part. The input shaft 23 has an outwardly protruding annular step located on the side of the first bearing away from the housing 11 and abuts against the inner ring of the first bearing. The rotor shaft 12 has a coaxially arranged spline hole at the end facing the transmission shaft hole 15, and the end of the input shaft 23 has a spline shaft that is inserted into the spline hole. The length of the spline shaft is less than the depth of the spline hole. A first dynamic seal assembly is provided between the input shaft 23 and the transmission shaft hole 15.

[0023] The housing cover 22 has an output shaft hole coaxially arranged with the output shaft 24, and the output shaft 24 is rotatably inserted through the output shaft hole via a second dynamic seal assembly. The drive shaft hole 15 has a first retaining ring groove extending circumferentially, and the annular limiting portion is a first retaining ring 16 fitted within the first retaining ring groove; the annular step is a shoulder protruding from the input shaft 23. The first dynamic seal assembly is located on the side of the first retaining ring 16 facing the rotor shaft 12. The output shaft hole has a second retaining ring groove coaxially arranged and fitted with a second retaining ring 27, and the second dynamic seal assembly is located on the side of the second retaining ring 27 facing outwards.

[0024] The reduction gear set includes an input gear 25 coaxially mounted on the input shaft 23 and an output gear 26 coaxially mounted on the output shaft 24, wherein the input gear 25 and the output gear 26 mesh with each other. In this embodiment, the input gear 25 is integrally formed on the input shaft 23, and the output gear 26 is integrally formed on the output shaft 24.

[0025] The two ends of the input shaft 23 are rotatably mounted on the gearbox body 21 and the cover 22 via deep groove ball bearings; the two ends of the output shaft 24 are rotatably mounted on the gearbox body 21 and the cover 22 via cylindrical roller bearings.

[0026] The electric drive structure of this embodiment integrates the gearbox body into the front end cover, allowing the motor and gearbox to share the same end cover. This results in a more compact structure, enabling the placement of a higher-power motor within a limited space and improving overall power output. Furthermore, by passing the gearbox's input shaft through the drive shaft hole, and then inserting it into the motor and coaxially engaging it with the motor's rotor shaft via splines, the input shaft can be separated from the motor, reducing the difficulty of maintenance and replacement. This also ensures the rotor shaft remains within the front end cover, preventing accidental damage during maintenance or assembly and reducing the risk of failure. Simultaneously, because the length of the spline on the input shaft is less than the depth of the spline hole on the rotor shaft, no axial thrust is generated between the input and rotor shafts, thus preventing axial stress on the motor bearings and extending the motor's lifespan.

[0027] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An electric drive assembly, comprising a motor (1) and a gearbox (2), wherein the motor (1) comprises a housing (11) and a rotor shaft (12), and a rear end cover (13) and a front end cover (14) are respectively provided at both ends of the housing (11); the gearbox (2) comprises a gearbox body (21) integrally formed on the front end cover (14), the gearbox body (21) being located on the side of the front end cover (14) away from the housing (11) and being fitted with a cover (22), wherein an input shaft (23) and an output shaft (24) are arranged parallel to each other between the gearbox body (21) and the cover (22), and a reduction gear set is provided between the input shaft (23) and the output shaft (24); characterized in that, The front end cover (14) has a transmission shaft hole (15) coaxial with the rotor shaft (12). The input shaft (23) is rotatably disposed in the transmission shaft hole (15) through the first bearing and is coaxially connected with the rotor shaft (12). The transmission shaft hole (15) has an inwardly protruding annular limiting part, which is located on the side of the first bearing facing the housing (11) and abuts against the outer ring of the first bearing. The input shaft (23) has an outwardly protruding annular step, which is located on the side of the first bearing away from the housing (11) and abuts against the inner ring of the first bearing.

2. The electric drive assembly as described in claim 1, characterized in that, The rotor shaft (12) is rotatably mounted on the rear end cover (13) and the front end cover (14) by bearings at both ends, and has a coaxial spline hole at one end facing the transmission shaft hole (15); the input shaft (23) has a spline shaft at the end that is inserted into the spline hole, and the length of the spline shaft is less than the depth of the spline hole.

3. The electric drive assembly as described in claim 1, characterized in that, The drive shaft hole (15) has a first retaining ring groove extending circumferentially, and the annular limiting part is a first retaining ring (16) that fits in the first retaining ring groove.

4. The electric drive assembly as described in claim 1, characterized in that, The reduction gear set includes an input gear (25) coaxially mounted on the input shaft (23) and an output gear (26) coaxially mounted on the output shaft (24), wherein the input gear (25) and the output gear (26) mesh with each other.

5. The electric drive assembly as described in claim 4, characterized in that, The input gear (25) is integrally formed on the input shaft (23), and the output gear (26) is integrally formed on the output shaft (24).

6. The electric drive assembly as claimed in claim 1, characterized in that, The two ends of the input shaft (23) are rotatably mounted on the gearbox body (21) and the cover (22) by deep groove ball bearings; the two ends of the output shaft (24) are rotatably mounted on the gearbox body (21) and the cover (22) by cylindrical roller bearings.

7. The electric drive assembly as claimed in claim 1, characterized in that, A first dynamic sealing assembly is provided between the input shaft (23) and the transmission shaft hole (15), and the first dynamic sealing assembly is located on the side of the annular limiting part facing the housing (11).

8. The electric drive assembly as claimed in claim 1, characterized in that, The cover (22) has an output shaft hole coaxially arranged with the output shaft (24), and the output shaft (24) is rotatably inserted through the output shaft hole by a second dynamic sealing assembly.

9. The electric drive assembly as claimed in claim 8, characterized in that, The output shaft hole has a second snap ring groove coaxially arranged and a second snap ring (27) is fitted therein. The second dynamic seal assembly is located on the side of the second snap ring (27) facing outward.

10. An electric vehicle, characterized in that, Includes the electric drive assembly as described in any one of claims 1 to 9.

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