CN113890258A

CN113890258A - Motor assembly of electric drive axle and electric drive axle

Info

Publication number: CN113890258A
Application number: CN202111173250.1A
Authority: CN
Inventors: 梁志; 彭南江; 莫建伟; 陈振保; 陈超宇; 姚明良; 杨杰; 焦传梅
Original assignee: Liuzhou Wuling Automobile Industry Co Ltd; Guangxi Automobile Group Co Ltd
Current assignee: Liuzhou Wuling Automobile Industry Co Ltd; Guangxi Automobile Group Co Ltd
Priority date: 2021-10-08
Filing date: 2021-10-08
Publication date: 2022-01-04
Anticipated expiration: 2041-10-08
Also published as: CN113890258B

Abstract

The invention discloses a motor assembly of an electric drive axle and the electric drive axle, wherein the motor assembly comprises a driving motor and a bearing oil seal component; the bearing oil seal assembly comprises a mounting seat provided with a mounting hole, and a motor oil seal, a middle bearing of the long half shaft and a first half shaft oil seal of the long half shaft which are sequentially arranged in the mounting hole along the front and rear directions; the driving motor comprises an end cover and a rotary transformer, wherein the end cover is provided with a mounting hole, and the rotary transformer and the bearing oil seal assembly are sequentially mounted in the mounting hole along the front direction and the rear direction. Motor oil blanket, middle bearing and first axle oil blanket all assemble on the mount pad as a whole, set up simultaneously in the mounting hole of end cover with resolver, like this, when the resolver timing, can go on before the assembly of bearing oil blanket subassembly, or if operation such as need zero setting or other maintenance after the assembly, also can dismantle bearing oil blanket subassembly from the end cover, can not obstruct the operation of resolver.

Description

Motor assembly of electric drive axle and electric drive axle

Technical Field

The invention relates to the technical field of drive axles, in particular to a motor assembly of an electric drive axle and the electric drive axle.

Background

Referring to FIG. 1, FIG. 1 is an enlarged view of the drive motor and differential assembly position in an electric drive axle.

The motor 03 and the differential 04 on the electric drive axle are located on the same axis, so that the half shaft on one side needs to pass through the rotor shaft of the motor 03 first and then reach the differential 04, and the half shaft on the other side is arranged adjacent to the differential 04. Because the motor 03 has a certain length, the half shaft passing through the motor 03 is particularly long, namely a long half shaft 01, while the half shaft on the other side is relatively short, namely a short half shaft 02. This causes a certain stiffness problem for the major half shaft 01, while the minor half shaft 02 is relatively stiff due to its shorter length.

As shown in fig. 1, in order to solve the problem of poor swinging and rigidity caused by the overlong length of the long half shaft 01, a middle bearing 05 is usually added in the middle of the long half shaft 01 to restrain the radial movement of the middle position of the long half shaft 01, so as to improve the rigidity of the long half shaft 01 and ensure the normal operation of the long half shaft 01 to transmit torque, and in fig. 1, the middle bearing 05 is arranged in an end cover of a motor 03.

In addition, the transaxle reducer must be filled with gear oil for lubricating rotating components such as gears, bearings, and differentials, but the half shafts must extend from the interior of the reducer to transmit torque and rotation speed, and the extended hole sites of the long half shaft 01 or the short half shaft 02 must be sealed in the form of oil seals to prevent the gear oil from flowing out. As shown in fig. 1, the oil seal 06 of the long half shaft 01 is generally arranged in the middle of the rod part of the long half shaft 01, and the outer ring of the oil seal 06 is fixed on the motor end cover and positioned beside the middle bearing 05; the oil seal of the stub axle 02 is arranged at a position of the stub axle 02 near the spline connected to the differential 04, and the outer ring of the oil seal is fixed to the reducer case.

With continued reference to fig. 1, the motor 03 will be equipped with a resolver 07, which is an electromagnetic sensor for measuring the angular displacement and speed of the rotating shaft of the rotating object, consisting of a stator and a rotor, which is required to be arranged at the position of the rotor shaft of the motor. Furthermore, the resolver 07 is generally required to be adjusted in the zero position when it is mounted on the motor 03.

Thus, the intermediate bearing 05 needs to support the long half shaft 01 part outside the rotor shaft of the motor, and the intermediate bearing 05 and the oil seal 06 of the long half shaft 01 are necessarily positioned outside the rotary transformer 07, so that the internal rotary transformer 07 is shielded, and the electric drive axle of the type cannot be adjusted to a uniform rotation angle when being delivered from a factory, so that the controller of the motor 03 can only adopt one-to-one matching, and the interchangeability is avoided, and the adverse effect can be caused on large-scale production and later maintenance.

Disclosure of Invention

The invention provides a motor assembly of an electric drive axle, wherein the electric drive axle comprises a long half shaft and a short half shaft, and the motor assembly comprises a driving motor and a bearing oil seal component; the bearing oil seal assembly comprises a mounting seat provided with a mounting hole, and a motor oil seal, a middle bearing of a long half shaft and a first half shaft oil seal of the long half shaft which are axially arranged in the mounting hole, wherein the motor oil seal (14) is positioned on the front sides of the middle bearing (13) and the first half shaft oil seal (2);

the driving motor comprises an end cover and a rotary transformer, the end cover is provided with mounting holes, and the rotary transformer and the bearing oil seal assembly are sequentially mounted in the mounting holes along the front direction and the rear direction.

In a specific embodiment, the hole wall of the mounting hole is provided with a first limiting portion and a second limiting portion, and the intermediate bearing is mounted between the first limiting portion and the second limiting portion.

In a specific embodiment, at least one of the first limiting portion and the second limiting portion is a circlip.

In a specific embodiment, the mounting hole includes a small hole and a large hole which are connected with each other and distributed along the front and the back, a step between the small hole and the large hole forms the first limiting part, and the second limiting part is the elastic collar; the first half shaft oil seal is arranged in the big hole, and the motor oil seal is arranged in the small hole.

In one embodiment, the mounting seat is fixed in the mounting hole through a fastener; or the mounting seat is provided with external threads, the mounting hole is provided with matched internal threads, and the mounting seat is in threaded connection with the mounting hole.

The invention also provides an electric drive axle, which comprises a long half shaft, a short half shaft and the motor assembly as described in any one of the above items.

In a specific embodiment, at least one of the long half shaft and the short half shaft is provided with a bushing, the bushing is sleeved outside and in interference fit with the corresponding long half shaft or short half shaft, and the periphery of the bushing is in dynamic sealing fit with an inner hole of the corresponding first half shaft oil seal or the second half shaft oil seal of the short half shaft.

In one embodiment, the half-shafts form a journal and a shoulder, the bushing surrounding the journal, the shoulder for retaining the corresponding bushing, the shoulder being located behind the journal.

In one embodiment, the intermediate bearing is an interference fit or a small clearance fit with the journal.

In one embodiment, the liner is a steel collar.

In this scheme, all assemble as a holistic bearing oil blanket subassembly on the mount pad with motor oil blanket, intermediate shaft and first axle oil blanket, and set up simultaneously in the second mounting hole of end cover with resolver, like this, when needs turn to resolver zero, can go on before the assembly of bearing oil blanket subassembly, perhaps, if need turn to resolver zero or operation such as other maintenance after the assembly, also can dismantle bearing oil blanket subassembly from the end cover, can not obstruct the operation to resolver.

Drawings

FIG. 1 is an enlarged view of the drive motor and differential assembly position in an electric transaxle;

FIG. 2 is a schematic diagram of an electric drive axle provided in accordance with an embodiment of the present invention;

FIG. 3 is an enlarged view of portion A of FIG. 2;

fig. 4 is an enlarged view of a portion B in fig. 2.

The reference numerals are explained below:

01-long half shaft; 02-short half shaft; 03-a motor; 04-a differential mechanism; 05-an intermediate bearing; 06-oil sealing; 07-a rotary transformer;

1-a bearing oil seal assembly;

11-a mounting seat; 11 a-step; 12-a first semi-axis oil seal; 13-an intermediate bearing; 14-motor oil seal; 15-elastic retainer ring;

21-long half axis; 21 a-a first shoulder; 21 b-a first journal; 21c — a first spline;

22-short half shaft; 22 a-a second shoulder; 22 b-second journal; 22 c-a second spline;

3-driving a motor;

31-end cap; 31 a-a second mounting hole; 32-a rotor shaft;

41-a first bushing; 42-a second bushing;

5-rotary transformer

6-a differential;

7-second half shaft oil seal.

Detailed Description

In order that those skilled in the art will better understand the disclosure, the invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 2, fig. 2 is a schematic view of an electric drive axle according to an embodiment of the present invention.

The embodiment provides an electric drive axle and a motor assembly thereof, the electric drive axle comprises a drive motor 3 and a differential mechanism 6 which are coaxially arranged, and because the drive motor 3 and the differential mechanism 6 are coaxially arranged, two half shafts of the electric drive axle are respectively a long half shaft 21 and a short half shaft 22, the long half shaft 21 penetrates through a rotor shaft 32 of the drive motor 3 to be connected with the differential mechanism 6, and the short half shaft 22 and the differential mechanism 6 are adjacently arranged.

Referring to fig. 3, fig. 3 is an enlarged schematic view of a portion a in fig. 2.

In the scheme, the motor assembly comprises a driving motor 3 and a bearing oil seal component 1, wherein the bearing oil seal component 1 comprises a mounting seat 11 provided with a first mounting hole, a motor oil seal 14 arranged in the first mounting hole along the axial direction, a middle bearing 13 of a long half shaft 21 and a half shaft oil seal of the long half shaft 21, and the half shaft oil seal of the long half shaft 21 is defined as a first half shaft oil seal 12. The motor oil seal 14, the intermediate bearing 13 and the first half shaft oil seal 12 are sequentially distributed along the front and rear directions, in fig. 3, the motor oil seal 14 is located at the foremost side, the intermediate bearing 13 is located between the first half shaft oil seal 12 and the motor oil seal 14, and of course, the first half shaft oil seal 12 may also be located between the intermediate bearing 13 and the motor oil seal 14. The first semi-axis oil seal 12 is used for sealing oil leakage, and the motor oil seal 14 prevents the oil from flowing inwards into the driving motor 3.

The terms "forward" and "rearward" are used herein with reference to the connecting ends of the respective half shafts to which the differential 6 is connected, and "forward" and "rearward" are used herein with reference to the connecting ends. In the view of fig. 2, the portion of the major half-axis 21, forward to the right and rearward to the left, and the portion of the minor half-axis 22, forward to the left and rearward to the right, can also be understood with reference to a differential 6, forward adjacent to the differential 6, and rearward to the contrary. In fig. 3, the motor oil seal 14, the intermediate bearing 13 and the first axle shaft oil seal 12 are distributed from right to left.

As shown in fig. 3, the driving motor 3 includes an end cover 31 and the rotary transformer 5, the bearing oil seal assembly 1 is designed for the half shaft 21, the end cover 31 is also an end cover of the driving motor 3 corresponding to one side of the half shaft 21, the end cover 31 is provided with a second mounting hole 31a, the rotary transformer 5 and the bearing oil seal assembly 1 are sequentially mounted in the second mounting hole 31a along the front and rear directions, and the hole wall of the second mounting hole 31a may be provided with a step to separate the bearing oil seal assembly 1 from the rotary transformer 5.

It should be noted that the motor oil seal 14 needs to be matched with the rotor shaft 32, and the middle bearing 13 and the first half shaft oil seal 12 of the long half shaft 21 need to be matched with the long half shaft 21, so that both are of an annular structure, accordingly, the axis of the first mounting hole of the mounting seat 11 of the bearing oil seal assembly 1 is parallel to the long half shaft 21 and the rotor shaft 32, and is preferably coaxially arranged, so as to enable the stress to be uniform, and similarly, the second mounting hole 31a formed in the end cover 31 is also preferably coaxially arranged with the first mounting hole.

With such an arrangement, referring to fig. 3, in the present embodiment, the motor oil seal 14, the intermediate bearing 13 and the first half shaft oil seal 12 are all assembled on the mounting seat 11 as the integral bearing oil seal assembly 1, and are disposed in the second mounting hole 31a of the end cover 31 simultaneously with the resolver 5, so that when the resolver 5 needs to be zeroed, the assembly can be performed before the bearing oil seal assembly 1 is assembled, or if the resolver 5 needs to be zeroed or otherwise repaired after the assembly, the bearing oil seal assembly 1 can be detached from the end cover 31, which does not hinder the operation of the resolver 5. In order to operate the rotary transformer 5, it is obvious that, in the second mounting hole 31a, a rear-to-front operation tool or a hand of an operator can enter a position where the rotary transformer 5 is located so as to zero or perform other operations on the rotary transformer 5, but the specific size and the structural design scheme of the second mounting hole 31a are not further limited, and the second mounting hole 31a may be tapered or arranged with an equal diameter from the rear to the front.

In this scheme, the bearing oil seal assembly 1 is detachably assembled in the second mounting hole 31a, in order to facilitate the disassembly, the mounting seat 11 can be fixed in the second mounting hole 31a of the end cover 31 through a fastener, the fastener can be a bolt, for example, and the mounting seat 11 and the end cover 31 are provided with corresponding screw holes. Or, an external thread may be provided on the periphery of the mounting seat 11, and a matching internal thread is formed on the hole wall of the second mounting hole 31a, so that the mounting seat 11 is in threaded connection with the second mounting hole 31a, and at this time, the bearing oil seal assembly 1 may be directly screwed into the second mounting hole 31a of the end cover 31, and the mounting and dismounting are also very simple.

Referring to fig. 3, the hole wall of the first mounting hole of the mounting seat 11 is provided with a first limiting portion and a second limiting portion, specifically, in this embodiment, the second limiting portion is an elastic collar 15, the first limiting portion is formed by a step 11a formed by the hole wall of the first mounting hole, at this time, the intermediate bearing 13 is installed between the first limiting portion and the second limiting portion to be axially limited, so that the mounting position is stable, and the intermediate bearing is isolated from the motor oil seal 14 and the first half-shaft oil seal 12. As shown in fig. 3, the first mounting hole is a stepped hole, and includes a small hole and a large hole which are connected and distributed along the front and the back, the step 11a is formed between the small hole and the large hole, the first half shaft oil seal 12 at this time can be mounted in the large hole, the motor oil seal 14 is mounted in the small hole, and the peripheral diameter of the motor oil seal 14 at this time is smaller than that of the first half shaft oil seal 12, it can be understood that the first mounting hole is not limited to be a stepped hole according to the structural size design of the first half shaft oil seal 12, the motor oil seal 14, and the intermediate bearing 13, for example, the first limiting portion may be an annular partition plate whose hole wall extends inward. In fact, both limiting parts can be elastic retainer rings 15, and one limiting part is formed by the step 11a, so that the requirements of the installation size of the motor oil seal 14 and the intermediate bearing 13 are met, and the limiting parts also play a role of a relatively rigid isolation stop. The second limiting part adopts an elastic retainer ring 15, which is beneficial to realizing that the middle bearing 13 is arranged between the first limiting part and the second limiting part.

Referring to fig. 2 and 3, and being understood in conjunction with fig. 4, fig. 4 is an enlarged schematic view of a portion B in fig. 2.

In the present embodiment, the major half shaft 21 and the minor half shaft 22 are provided with bushings, which are respectively defined as a first bushing 41 and a second bushing 42, wherein the first bushing 41 is sleeved outside and interference-fitted with the corresponding major half shaft 21, the second bushing 42 is sleeved outside and interference-fitted with the corresponding minor half shaft 22, the outer periphery of the first bushing 41 is in dynamic sealing fit with the inner hole of the first half shaft oil seal 12, the outer periphery of the second bushing 42 is in dynamic sealing fit with the inner hole of the second half shaft oil seal 7, and the bushings can be steel bushings or sleeve-shaped structures made of other rigid materials.

Describing the cooperation of the first bushing 41 and the long half shaft 21, as shown in fig. 3, the first bushing 41 and the long half shaft 21 are in interference fit, and the first bushing 41 and the inner hole of the first half shaft oil seal 12 are in dynamic seal fit, so that the inner hole of the first half shaft oil seal 12 does not need to match with the outer diameter of the long half shaft 21, and can be larger than the outer diameter of the long half shaft 21 by approximately the thickness of the first bushing 41, that is, compared with the background art, the hole diameter of the inner hole of the first half shaft oil seal 12 is enlarged, so that when the first half shaft oil seal 12 and the long half shaft 21 are assembled, the connecting end on the front side of the long half shaft 21 is not easy to contact with and press against the lip of the first half shaft oil seal 12 to damage the lip, and the connecting end of the long half shaft 21 is generally provided with splines, which are defined as first splines 21c here for connecting with the differential 6. The connecting end of the stub axle 22 is also provided with splines for connecting with the differential, which is defined as a second spline 22c, and the second bushing 42 and the stub axle 22 are matched in the same principle, which is equivalent to enlarging the aperture of the second axle oil seal 7, and avoiding or reducing the damage of the second spline 22c at the connecting end of the stub axle 22 to the lip of the second axle oil seal 7.

With continued reference to FIG. 3, the body of the stub shaft 21 has formed thereon a first journal 21b and a first shoulder 21a, the first shoulder 21a being located behind the first journal 21 b. The first bushing 41 and the intermediate bearing 13 are both sleeved on the first journal 21b, and the intermediate bearing 13 and the first journal 21b may be in an interference fit or a small clearance fit to ensure stable position and smooth transmission of the intermediate bearing 13. The first shoulder 21a serves to axially restrain the first bush 41 rearward to restrict the first bush 41 from moving axially rearward when the first bush 41 is press-fitted, and the circlip 15 does not contact the first bush 41. As shown in fig. 3, the portion of the half shaft 21 before the first journal 21b needs to pass through the inner bore of the rotor shaft 32 of the drive motor 3, and the radial dimension is designed to be slightly smaller than the dimension of the first journal 21b so as to facilitate insertion of the rotor shaft 32. As shown in fig. 4, the stub shaft 22 is also provided such that a second journal 22b and a second shoulder 22a are also formed on the shaft body of the stub shaft 22, the second shoulder 22a restricting rearward axial movement of the second bushing 42 when the second bushing 42 is press-fitted.

The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims

1. A motor assembly of an electric drive axle, the electric drive axle comprises a long half shaft and a short half shaft, and is characterized in that the motor assembly comprises a drive motor (3) and a bearing oil seal component (1); the bearing oil seal assembly (1) comprises a mounting seat (11) provided with a mounting hole, and a motor oil seal (14), a middle bearing (13) of a long half shaft (21) and a first half shaft oil seal (12) of the long half shaft (21) which are axially arranged in the mounting hole, wherein the motor oil seal (14) is positioned on the front side of the middle bearing (13) and the front side of the first half shaft oil seal (2);

the driving motor (3) comprises an end cover (31) and a rotary transformer (5), the end cover (31) is provided with a mounting hole, and the rotary transformer (5) and the bearing oil seal assembly (1) are sequentially mounted in the mounting hole along the front direction and the rear direction.

2. The electric drive axle assembly according to claim 1, wherein the wall of the mounting hole is provided with a first limiting portion and a second limiting portion, and the intermediate bearing (13) is mounted between the first limiting portion and the second limiting portion.

3. The electric drive axle assembly according to claim 2, wherein at least one of the first and second limiting portions is a circlip (15).

4. The motor assembly of the electric drive axle according to claim 3, wherein the mounting hole comprises a small hole and a large hole which are connected with each other and distributed along the front and the back, a step (11a) between the small hole and the large hole forms the first limiting part, and the second limiting part is the elastic retainer ring (15); the first half shaft oil seal (12) and the middle bearing (13) are arranged in the big hole, and the motor oil seal (14) is arranged in the small hole.

5. The electric motor assembly of the electric drive axle according to any one of claims 1 to 4, wherein the mounting seat (11) is fixed in the mounting hole by a fastener; or the mounting seat is provided with external threads, the mounting hole is provided with matched internal threads, and the mounting seat (11) is in threaded connection with the mounting hole.

6. An electric drive axle, characterized in that it comprises a longer half shaft (21), a shorter half shaft (22) and an electric machine assembly according to any one of claims 1-5.

7. The electric drive axle according to claim 6, characterized in that at least one of the half-shaft (21) and the half-shaft (22) is provided with a bushing which houses and interference fits the corresponding half-shaft (21) or half-shaft (22), the outer periphery of the bushing being in dynamic sealing fit with the inner bore of the second half-shaft oil seal (7) of the corresponding first half-shaft oil seal (12) or half-shaft (22).

8. Electric drive axle according to claim 7, characterized in that the half-shafts (21, 22) form journals and shoulders, which sleeve the journal, for the purpose of limiting the corresponding bushing, the shoulders being located behind the journal.

9. Electric drive axle according to claim 8, characterized in that the intermediate bearing (13) is an interference fit or a small clearance fit with the journal.

10. The electric drive axle of claim 8 wherein said bushing is a steel bushing.