Coaxial electric drive axle

Abstract

A coaxial electric drive axle comprises an electric drive assembly and an electric drive axle housing, the drive assembly comprises a housing, a motor, a speed reducer gear set and a differential mechanism, the motor, the speed reducer gear set and the differential mechanism are arranged in the electric drive axle housing of an integrated structure, the electric drive axle housing comprises a main axle housing and a rear cover, the main axle housing is provided with a mounting cavity, the rear side of the main axle housing is connected with the rear cover, and the front side of the main axle housing is connected with the housing. The shell is provided with a stator fixing plate, a motor stator is fixed on the stator fixing plate, a motor shaft, an intermediate shaft and a differential mechanism are supported on the shell through bearings, the motor shaft is connected with the differential mechanism through a speed reducer gear set, the shell is connected with a main axle housing, and the motor, a primary driving gear, a secondary driven gear and the differential mechanism are arranged in a main axle housing mounting cavity. The motor shaft is a hollow shaft, one end of the left-end half shaft penetrates through the motor shaft to be connected with a differential mechanism left half shaft bevel gear, and one end of the right-end half shaft is connected with a differential mechanism right half shaft bevel gear.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicles, and in particular to a coaxial electric drive bridge. Background Art

[0002] At present, the electric drive axles of new energy vehicles can be divided into parallel-axis electric drive axles and coaxial electric drive axles. The motor shaft of the parallel-axis electric drive axle is parallel to the half-axis, but the motor shaft and the half-axis are not on the same axis; the motor shaft of the coaxial electric drive axle is a hollow shaft, and the half-axis passes through the motor rotor and the motor shaft of the motor shaft, so that the motor shaft and the half-shaft are on the same axis; the coaxial electric drive axle has the advantages of less vibration, compact structure and low mass compared to the parallel-axis electric drive axle.

[0003] In the prior art, such as the invention patent "A semi-coaxial electric drive axle assembly" with application publication number CN110469645A, in order to facilitate the installation of motors, differentials and other components, the coaxial electric drive axle is divided into multiple housings such as motor end cover, motor mounting housing, differential mounting housing, etc. along the axial direction of the motor shaft, the motor is installed in the motor mounting housing, the differential is installed in the differential mounting housing, the multiple housings are fixedly connected by bolts, and the motor end cover and the differential mounting housing are fixedly connected to the left bridge tube and the right bridge tube by bolts respectively. However, since the bridge tube of the coaxial electric drive axle needs to bear the torque of the electric drive axle, when the left and right bridge tubes of this coaxial electric drive axle are subjected to large torque, the positions of the bearings installed in the motor mounting housing and the differential mounting housing are easily deformed, resulting in damage to the bearings, thereby damaging the motor, differential and other components in the housing, seriously affecting the service life of the coaxial electric drive axle. Moreover, when components such as the motor and differential are damaged or malfunction, the entire coaxial electric drive axle must be dismantled to replace and repair the damaged components, and the after-sales repair cost is extremely high. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention proposes a coaxial electric drive axle, which greatly enhances the carrying capacity of the electric drive axle by integrally forming the electric drive axle housing with the left and right bridge tubes. At the same time, the electric drive assembly is separated from the electric drive axle housing to reduce after-sales maintenance costs.

[0005] The technical solution of the present invention is a coaxial electric drive axle, including an electric drive assembly and an electric drive axle housing, the drive assembly includes a housing, a motor, a reducer gear set, and a differential, the motor, the reducer gear set, and the differential are arranged in an electric drive axle housing with an integrated structure, the electric drive axle housing includes a main axle housing and a rear cover, the main axle housing is provided with a mounting cavity that passes through front and rear, the rear side of the main axle housing is fixedly connected to the rear cover, the front side of the main axle housing is fixedly connected to the housing of the drive assembly, the housing is provided with a stator fixing plate, and the stator of the motor is fixed on the stator fixing plate The motor shaft of the motor, the intermediate shaft of the reducer gear set, and the differential are supported on the housing through bearings respectively. The motor shaft is connected to the differential through the reducer gear set. The housing is fixedly connected to the main bridge housing through bolts, so that the motor, the first-stage driving gear, the second-stage driven gear, and the differential of the reducer gear set are located in the installation cavity of the main bridge housing, and their central axes are all on the same straight line. The motor shaft is a hollow shaft, and one end of the left half shaft passes through the motor shaft to connect the left half shaft bevel gear of the differential, and one end of the right half shaft is connected to the right half shaft bevel gear of the differential.

[0006] Preferably, the reducer gear set also includes a primary driven gear and a secondary driving gear, the primary driving gear is fixedly connected to the motor shaft, the primary driven gear and the secondary driving gear are fixedly connected to the intermediate shaft of the reducer gear set, and the secondary driven gear is fixedly connected to the differential housing, the primary driving gear is meshed with the primary driven gear, and the secondary driving gear is meshed with the secondary driven gear.

[0007] Furthermore, the secondary driving gear and the intermediate shaft are an integrally formed structure.

[0008] Preferably, the stator fixing plate is fixedly connected to a bearing mounting sleeve, in which a left differential bearing and a primary driving gear of a reducer gear set are arranged, and the left differential bearing is used to support the left side of the differential.

[0009] Furthermore, the bearing mounting sleeve is provided with an engagement opening, and the primary driving gear is engaged with the primary driven gear of the reducer gear set through the engagement opening.

[0010] Preferably, the housing includes a main housing, a reduction gear cover, and a motor rear cover, the reduction gear cover and the motor rear cover are fixed to the main housing by bolts, a bearing groove is provided at the connection between the reduction gear cover and the main housing, and a bearing is provided in the bearing groove for supporting the intermediate shaft of the reducer gear set, a left motor bearing seat is integrally formed on the motor rear cover, and the left motor bearing seat supports the left side of the motor shaft through the left motor bearing, a stator fixing plate is provided on the main housing, and a right motor bearing is fixed on the stator fixing plate for supporting the right side of the motor shaft, and a right differential bearing seat is also provided on the main housing, and the right differential bearing seat supports the right side of the differential through the right differential bearing.

[0011] Furthermore, the right bearing seat of the differential includes a base and a bearing cover, the base is integrally formed with the main housing, and the bearing cover is connected and fixed to the base by bolts.

[0012] Preferably, the stator of the motor is provided with a fixing through hole, and the stator fixing plate is provided with a threaded hole corresponding to the fixing through hole of the stator, and the stator is fixed to the stator fixing plate by long bolts.

[0013] Preferably, a plurality of mounting holes are evenly distributed on the housing, and the housing is fixed to the main bridge housing by bolts, so that the center line of the main bridge housing coincides with the center line of the drive assembly to form a closed space.

[0014] Preferably, the motor further comprises a rotor, which is arranged inside the stator, and the rotor shaft of the rotor is the motor shaft.

[0015] The advantages of the present invention are as follows: the present invention greatly improves the carrying capacity of the coaxial electric drive bridge by integrally forming the electric drive bridge housing with the left and right bridge tubes. At the same time, by radially arranging the housing and the rear cover, the problem that the bearing position in the housing is easily deformed by force when the bridge tube is subjected to a large torque is avoided, thereby ensuring the normal operation of the bearing and greatly improving the service life of the coaxial electric drive bridge. Moreover, the present invention separates the electric drive assembly from the electric drive bridge housing. When parts in the electric drive assembly are damaged and need to be repaired and replaced, only the electric drive assembly can be removed and the damaged parts can be replaced, thereby avoiding the problem of removing the entire electric drive bridge from the vehicle body to replace the damaged parts, thereby greatly reducing the after-sales and maintenance costs of new energy vehicles using the coaxial electric drive bridge of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the electric drive assembly and the electric drive axle housing of the present invention; Figure 2 is a cross-sectional schematic diagram of the electric drive assembly of the present invention; Figure 3 It is a structural schematic diagram of the electric drive assembly of the present invention; Figure 4 It is a schematic diagram of the housing structure of the electric drive assembly of the present invention; Figure 5 It is a structural schematic diagram of the motor of the present invention; Figure 6 It is a cross-sectional schematic diagram of the present invention. DETAILED DESCRIPTION

[0017] See also Figures 1 to 6A coaxial electric drive axle comprises an electric drive assembly 1 and an electric drive axle housing 2. The drive assembly 1 comprises a housing 11, a motor 12, a reducer gear set 13, and a differential 14. The motor 12, the reducer gear set 13, and the differential 14 are arranged in an electric drive axle housing 2 with an integrated structure. The electric drive axle housing 2 comprises a main axle housing 21 and a rear cover 22. The main axle housing 21 is provided with an installation cavity that passes through from front to back. The rear side of the main axle housing 21 is fixedly connected to the rear cover 22, and the front side of the main axle housing 21 is fixedly connected to the housing 11 of the drive assembly 1. The housing 11 is provided with a stator fixing plate 114. A fixing through hole is provided on the stator 121 of the motor 12. The stator fixing plate 114 is provided with a threaded hole corresponding to the fixing through hole of the stator 121. The stator 121 is fixed to the stator fixing plate 114 by a long bolt. The stator fixing plate 114 is fixedly connected to a bearing mounting sleeve 15, in which a differential left bearing 342 and a primary driving gear 131 of a reducer gear set 13 are arranged, and the differential left bearing 342 is used to support the left side of the differential. The bearing mounting sleeve 15 is provided with an engagement opening, and the primary driving gear 131 is engaged with the primary driven gear of the reducer gear set 13 through the engagement opening. The motor 12 also includes a rotor 122, which is arranged inside the stator 121, and the rotor shaft of the rotor 122 is the motor shaft 1221. The housing 11 includes a main housing 111, a reduction gear cover 112, and a motor rear cover 113. The reduction gear cover 112 and the motor rear cover 113 are fixed to the main housing 111 by bolts. A bearing groove is provided at the connection between the reduction gear cover 112 and the main housing 111. The bearing groove is provided with a bearing for supporting the intermediate shaft of the reducer gear set 13. A motor left bearing seat is integrally formed on the motor rear cover 113. The motor left bearing seat supports the left side of the motor shaft 1221 through the motor left bearing 321. The main housing 111 is provided with a stator fixing plate 114. The motor right bearing 322 is fixed on the stator fixing plate 114 to support the right side of the motor shaft 1221. The main housing 111 is also provided with a differential right bearing seat. The differential right bearing seat includes a base and a bearing cover 115. The base is integrally formed with the main housing 111, and the bearing cover 115 is connected and fixed to the base by bolts. The differential right bearing seat supports the right side of the differential through the differential right bearing 341. The reducer gear set 13 also includes a primary driven gear 132 and a secondary driving gear 133. The primary driving gear 131 is fixedly connected to the motor shaft, the primary driven gear 132 and the secondary driving gear 133 are fixedly connected to the intermediate shaft of the reducer gear set 13. The secondary driving gear 133 and the intermediate shaft are an integrally formed structure. The secondary driven gear 134 is fixedly connected to the housing of the differential 14. The primary driving gear 131 is meshed with the primary driven gear 132, and the secondary driving gear 133 is meshed with the secondary driven gear 134.A plurality of mounting holes are evenly distributed on the housing 11, and the housing 11 is fixed to the main bridge housing 21 by bolts, so that the center line of the main bridge housing 21 coincides with the center line of the drive assembly 1 to form a closed space. At the same time, the motor 12, the first-stage driving gear 131 of the reducer gear set 13, the second-stage driven gear 134, and the differential 14 are located in the installation cavity of the main bridge housing 21, and their central axes are all on the same straight line. The motor shaft 1221 is a hollow shaft, and one end of the left half shaft 41 passes through the motor shaft to connect the left half shaft bevel gear of the differential 14, and one end of the right half shaft 42 is connected to the right half shaft bevel gear of the differential 14.

[0018] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A coaxial electric drive axle, comprising an electric drive assembly (1) and an electric drive axle housing (2), wherein the drive assembly (1) comprises a housing (11), a motor (12), a reducer gear set (13), and a differential (14), characterized in that: The motor (12), the speed reducer gear set (13), and the differential (14) are arranged in an electric drive axle housing (2) of an integrated structure. The electric drive axle housing (2) comprises a main axle housing (21) and a rear cover (22). The main axle housing (21) is provided with a mounting cavity that passes through from front to back. The rear side of the main axle housing (21) is fixedly connected to the rear cover (22). The front side of the main axle housing (21) is fixedly connected to a housing (11) of a drive assembly (1). The housing (11) is provided with a stator fixing plate (114). The stator (121) of the motor (12) is fixed on the stator fixing plate (114). The motor shaft (1221) of the motor (12), the intermediate shaft of the speed reducer gear set (13), and the differential (14) are fixedly connected to the housing (111) of the drive assembly (1). (14) are supported on the housing (11) through bearings, the motor shaft (1221) is connected to the differential (14) through the reducer gear set (13), and the housing (11) is fixedly connected to the main bridge housing (21) through bolts, so that the motor (12), the first-stage driving gear (131) of the reducer gear set (13), the second-stage driven gear (134), and the differential (14) are located in the installation cavity of the main bridge housing (21), and their central axes are all on the same straight line. The motor shaft (1221) is a hollow shaft, one end of the left half shaft (41) passes through the motor shaft and is connected to the left half shaft bevel gear of the differential (14), and one end of the right half shaft (42) is connected to the right half shaft bevel gear of the differential (14).

2. The coaxial electric drive axle according to claim 1, characterized in that: The reducer gear set (13) further comprises a primary driven gear (132) and a secondary driving gear (133); the primary driving gear (131) is fixedly connected to the motor shaft; the primary driven gear (132) and the secondary driving gear (133) are fixedly connected to the intermediate shaft of the reducer gear set (13); the secondary driven gear (134) is fixedly connected to the housing of the differential (14); the primary driving gear (131) meshes with the primary driven gear (132); and the secondary driving gear (133) meshes with the secondary driven gear (134).

3. The coaxial electric drive axle according to claim 2, characterized in that: The secondary driving gear (133) and the intermediate shaft are an integrally formed structure.

4. The coaxial electric drive axle according to claim 1, characterized in that: The stator fixing plate (114) is fixedly connected to a bearing mounting sleeve (15), and a left differential bearing (342) and a primary driving gear (131) of a speed reducer gear set (13) are arranged in the bearing mounting sleeve (15), and the left differential bearing (342) is used to support the left side of the differential.

5. The coaxial electric drive axle according to claim 4, characterized in that: The bearing mounting sleeve (15) is provided with an engagement opening, and the primary driving gear (131) is engaged with the primary driven gear of the reducer gear set (13) through the engagement opening.

6. The coaxial electric drive axle according to claim 1, characterized in that: The housing (11) comprises a main housing (111), a reduction gear cover (112), and a motor rear cover (113); the reduction gear cover (112) and the motor rear cover (113) are both fixed to the main housing (111) by bolts; a bearing groove is provided at the connection between the reduction gear cover (112) and the main housing (111); a bearing is provided in the bearing groove for supporting the intermediate shaft of the reduction gear set (13); a left motor bearing seat is integrally formed on the motor rear cover (113); the left motor bearing seat supports the left side of the motor shaft (1221) via the left motor bearing (321); a stator fixing plate (114) is provided on the main housing (111); a right motor bearing (322) is fixed on the stator fixing plate (114) for supporting the right side of the motor shaft (1221); and a right differential bearing seat is also provided on the main housing (111); the right differential bearing seat supports the right side of the differential via the right differential bearing (341).

7. The coaxial electric drive axle according to claim 6, characterized in that: The right bearing seat of the differential comprises a base and a bearing cover (115); the base and the main housing (111) are integrally formed; and the bearing cover (115) is connected and fixed to the base by bolts.

8. The coaxial electric drive axle according to claim 1, characterized in that: The stator (121) of the motor (12) is provided with a fixing through hole, and the stator fixing plate (114) is provided with a threaded hole corresponding to the fixing through hole of the stator (121), and the stator (121) is fixed to the stator fixing plate (114) by means of long bolts.

9. The coaxial electric drive axle according to claim 1, characterized in that: The housing (11) has a plurality of mounting holes evenly distributed thereon, and the housing (11) is fixed to the main axle housing (21) by means of bolts, so that the center lines of the main axle housing (21) and the drive assembly (1) coincide with each other, thereby forming a closed space.

10. The coaxial electric drive axle according to claim 1, characterized in that: The motor (12) further comprises a rotor (122), wherein the rotor (122) is arranged inside the stator (121), and the rotor shaft of the rotor (122) is the motor shaft (1221).

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