Electric drive assembly

Abstract

The invention discloses an electric drive assembly which comprises a drive assembly, a first transmission shaft, a second transmission shaft and a synchronizer. An output short half shaft of a differential mechanism assembly of the driving assembly is coaxially connected with a hollow motor shaft of a driving motor through an output half shaft; a first transmission shaft of the first transmission shaft assembly is in transmission connection with a hollow motor shaft of the driving motor through a first-stage gear set; a second transmission shaft of the second transmission shaft assembly is in transmission connection with the first transmission shaft through a second-stage high-speed gear set and a second-stage low-speed gear set. The second transmission shaft is in transmission connection with the differential mechanism assembly. The synchronizer is arranged on the second transmission shaft and located between the second-stage high-speed-gear gear set and the second-stage low-speed-gear gear set, and the gear sleeve can be in transmission connection with the second-stage high-speed-gear gear set and the second-stage low-speed-gear gear set. The first transmission shaft, the second transmission shaft and the hollow motor shaft are arranged in parallel and non-collinear. The number of transmission shafts and other parts can be reduced, the occupied space of the electric drive assembly is reduced, and efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of gearbox equipment, and more specifically, to an electric drive assembly. Background Art

[0002] Multi-speed drive assemblies have a significant effect in improving efficiency and are widely used in commercial vehicles, especially medium and heavy trucks with a vehicle weight of more than 8 tons. Multi-speed drive assemblies are also gradually being used in some high-performance passenger cars or off-road vehicles and pickup trucks that need to escape from difficulties.

[0003] Traditional multi-speed drive assemblies usually use a Y-type bridge two-speed drive assembly, that is, the motor, reducer and differential are arranged in a Y shape. The Y-type bridge two-speed drive assembly uses four parallel transmission shafts, and the power is output through the motor shaft of the motor at the same time. In addition, the motor shaft of the Y-type bridge two-speed drive assembly and the half shaft of the differential adopt different shaft designs, resulting in a large space occupied by the Y-type bridge two-speed drive assembly and low efficiency.

[0004] Therefore, how to reduce the space occupied by the electric drive assembly while improving the efficiency of the electric drive assembly has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the invention

[0005] In view of this, an object of the present application is to provide an electric drive assembly to reduce the space occupied by the electric drive assembly while improving the efficiency of the electric drive assembly.

[0006] To achieve the above objectives, this application provides the following technical solutions:

[0007] An electric drive assembly, comprising:

[0008] A drive assembly, the drive assembly comprising a drive motor and a differential assembly, wherein an output short half shaft of the differential assembly is coaxially connected to a hollow motor shaft of the drive motor via an output half shaft;

[0009] A first transmission shaft, which is transmission-connected to the hollow motor shaft of the driving motor via a primary gear set;

[0010] The second transmission shaft is connected to the first transmission shaft through a secondary low-speed gear set and a secondary high-speed gear set respectively, and the second transmission shaft is connected to the differential assembly through a third-stage gear set;

[0011] A synchronizer is arranged on the second transmission shaft, and the synchronizer is located between the secondary high-speed gear set and the secondary low-speed gear set, the synchronizer comprises a gear sleeve movable along the axial direction of the second transmission shaft and a gear hub drivingly connected to the second transmission shaft, the moving path of the gear sleeve comprises at least two working positions, and the two working positions of the gear sleeve are drivingly connected to the secondary high-speed gear set and drivingly connected to the secondary low-speed gear set respectively;

[0012] The first transmission shaft, the second transmission shaft and the hollow motor shaft are arranged in parallel, and the rotation centers of the first transmission shaft, the second transmission shaft and the hollow motor shaft are not collinear.

[0013] Optionally, in the above-mentioned electric drive assembly, the primary gear set includes a primary driving gear transmission-connected to the hollow motor shaft and a primary driven gear transmission-connected to the first transmission shaft, the primary driving gear is meshed with the primary driven gear, and a primary shaft retaining ring is provided on the outer side of the hollow motor shaft, and the primary shaft retaining ring is used to axially limit the primary driving gear.

[0014] Optionally, in the above-mentioned electric drive assembly, the first transmission shaft has a first end and a second end arranged opposite to each other, the primary driven gear is closer to the first end of the first transmission shaft than to the second end of the first transmission shaft, and a first bearing is provided at the first end of the first transmission shaft, and the first bearing is respectively fixed to the housing of the electric drive assembly and the first transmission shaft through two first bearing retaining rings, and a second bearing is provided at the second end of the first transmission shaft, and the second bearing is fixed to the first transmission shaft through the first shaft shoulder and the second bearing retaining ring of the first transmission shaft.

[0015] Optionally, in the above-mentioned electric drive assembly, the secondary low-speed gear set includes a secondary low-speed driving tooth portion fixed on the first transmission shaft and a secondary low-speed driven gear sleeved on the second transmission shaft, the secondary low-speed driven gear rotates relative to the second transmission shaft, the secondary low-speed driven gear is meshed with the secondary low-speed driving tooth portion, and the gear sleeve is used for transmission connection with the secondary low-speed driven gear.

[0016] Optionally, in the above-mentioned electric drive assembly, a low-speed combining tooth for meshing with the gear sleeve is fixed on the secondary low-speed driven gear, and a low-speed limiting step for limiting the moving stroke of the gear sleeve is provided on the low-speed combining tooth.

[0017] Optionally, in the above-mentioned electric drive assembly, one side of the gear hub abuts against the second shoulder of the second transmission shaft, a spacer sleeve is sleeved on the second transmission shaft, the spacer sleeve is interference fit with the second transmission shaft, and the spacer sleeve is pressed against the other side of the gear hub, and the secondary low-speed driven gear is rotatably sleeved on the spacer sleeve through a low-speed needle roller bearing.

[0018] Optionally, in the above electric drive assembly, a bearing stopper and a first gear stop ring for limiting axial movement of the gear hub are sequentially provided on a side of the spacer sleeve away from the gear hub.

[0019] Optionally, in the above-mentioned electric drive assembly, the secondary high-speed gear set includes a secondary high-speed driving gear transmission connected to the first transmission shaft and a secondary high-speed driven gear sleeved on the second transmission shaft, the secondary high-speed driving gear is fixed to the first transmission shaft through the third shaft shoulder and the second gear retaining ring of the first transmission shaft, the secondary high-speed driven gear rotates relative to the second transmission shaft, the secondary high-speed driven gear is meshed with the secondary high-speed driven gear, and the gear sleeve is used for transmission connection with the secondary high-speed driven gear.

[0020] Optionally, in the above-mentioned electric drive assembly, the secondary high-speed driven gear is rotatably mounted on the second transmission shaft through a high-speed needle roller bearing, and a high-speed combining tooth for engaging with the gear sleeve is fixed on the secondary high-speed driven gear, and a high-speed limiting step is provided on the high-speed combining tooth for limiting the moving stroke of the gear sleeve.

[0021] Optionally, in the above electric drive assembly, the three-stage gear set includes a three-stage driving tooth portion fixed on the second transmission shaft and a three-stage driven gear connected to the differential assembly, and the three-stage driving tooth portion is meshed with the three-stage driven gear.

[0022] The electric drive assembly provided by this application connects the output short half shaft of the differential assembly and the hollow motor shaft of the drive motor coaxially through the output half shaft. In emergency braking and other working conditions, the hollow motor shaft of the drive motor can move towards the output half shaft, reducing the deformation impact on the gear shaft system and achieving better NVH performance. At the same time, the first transmission shaft is connected to the hollow motor shaft of the drive motor through a first-stage gear set, and the second transmission shaft is connected to the first transmission shaft through a second-stage high-speed gear set and a second-stage low-speed gear set respectively. The second transmission shaft is connected to the differential assembly through a third-stage gear set. In addition, the synchronizer is arranged on the second transmission shaft with a lower rotational speed, and the synchronizer is located between the second-stage high-speed gear set and the second-stage low-speed gear set. By switching the gear sleeve between the working positions of the second-stage high-speed gear set and the second-stage low-speed gear set respectively, the switching between the low-speed gear and the high-speed gear is achieved. Moreover, the first transmission shaft, the second transmission shaft, and the hollow motor shaft are arranged in parallel, and the rotation centers of the first transmission shaft, the second transmission shaft, and the hollow motor shaft are not collinear, so that the layout of the electric drive assembly can be more compact. As can be seen from the above examples, compared with the Y-type two-speed drive assembly, the electric drive assembly provided by this application can reduce the use of parts such as transmission shafts, reduce costs, improve transmission efficiency, and at the same time, through three-stage deceleration, it is convenient to adjust the speed ratio. In addition, by arranging the first transmission shaft, the second transmission shaft, and the hollow motor shaft in parallel and non-collinear, the occupied space of the electric drive assembly can be reduced, making its layout more compact.

[0023] The technical features mentioned above, the technical features to be mentioned below, and the technical features shown separately in the drawings can be combined with each other arbitrarily as long as the combined technical features are not mutually contradictory. All feasible combinations of features are clearly recorded technical content in this article. Any one of the sub-features included in the same sentence can be applied independently without necessarily being applied together with other sub-features. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings.

[0025] Figure 1 It is a schematic structural diagram of the electric drive assembly provided by the embodiment of this application;

[0026] Figure 2 It is a schematic structural diagram of the drive component and the first transmission shaft provided by the embodiment of this application;

[0027] Figure 3 Structural schematic diagram of the drive component and the second transmission shaft provided by the embodiment of the present application;

[0028] Figure 4 Schematic diagram of the four-axis planar layout provided by the embodiment of the present application;

[0029] Figure 5 Schematic diagram of the power transmission path of the electric drive assembly provided by the embodiment of the present application.

[0030] Among them, 10 is the drive motor, 11 is the hollow motor shaft, 111 is the motor bearing, and 12 is the output half shaft;

[0031] 20 is the differential assembly, and 21 is the output short half shaft;

[0032] 31 is the first transmission shaft, 311 is the first bearing, 3111 is the first bearing retaining ring, 312 is the second bearing, 3121 is the first shaft shoulder, 3122 is the second bearing retaining ring, 313 is the third shaft shoulder, 32 is the first-stage gear set, 321 is the first-stage driving gear, 3211 is the first-stage shaft retaining ring, and 322 is the first-stage driven gear;

[0033] 41 is the second transmission shaft, 411 is the second shaft shoulder, 412 is the spacer sleeve, 4121 is the bearing retaining plate, 4122 is the first gear retaining ring, 413 is the third bearing, 414 is the fourth bearing, 42 is the second-stage low-speed gear set, 421 is the second-stage low-speed driving tooth part, 422 is the second-stage low-speed driven gear, 4221 is the low-speed engaging tooth, 4222 is the low-speed needle bearing, 43 is the second-stage high-speed gear set, 431 is the second-stage high-speed driving gear, 4311 is the second gear retaining ring, 432 is the second-stage high-speed driven gear, 4321 is the high-speed needle bearing, 4322 is the high-speed engaging tooth, 44 is the third-stage gear set, 441 is the third-stage driving tooth part, and 442 is the third-stage driven gear;

[0034] 50 is the synchronizer, 51 is the gear sleeve, 52 is the gear hub, 53 is the slider, and 54 is the synchronizing ring. Detailed implementation manners

[0035] The core of the present application is to provide an electric drive assembly to reduce the space occupied by the electric drive assembly while improving the efficiency of the electric drive assembly.

[0036] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0037] To this end, the embodiment of the present application discloses an electric drive assembly, including a drive assembly, a first transmission shaft 31, a second transmission shaft 41 and a synchronizer 50. Compared with the Y-type two-speed drive assembly, the use of parts such as the transmission shaft can be reduced, the cost is reduced, and the transmission efficiency is improved. At the same time, through the three-stage reduction, the speed ratio can be adjusted easily. In addition, by arranging the first transmission shaft 31, the second transmission shaft 41 and the hollow motor shaft 11 in parallel and not in a colinear manner, the occupied space of the electric drive assembly can be reduced, making its layout more compact.

[0038] The following will be combined Figures 1 to 5 The electric drive assembly disclosed in the embodiments of the present application is specifically explained and illustrated.

[0039] Among them, Figures 1 to 3 As shown, the drive assembly may include a drive motor 10 and a differential assembly 20, and the spline end of the output half shaft 12 may pass through the hollow motor shaft 11 of the drive motor 10 and be inserted into the differential assembly 20, so that the output short half shaft 21 of the differential assembly 20 and the hollow motor shaft 11 of the drive motor 10 are arranged with the same rotation axis, so that under emergency braking and other working conditions, the hollow motor shaft 11 of the drive motor 10 can move towards the output half shaft 12, reducing the deformation effect on the gear shaft system and achieving better NVH effect. It should be noted that the output half shaft 12 and the hollow motor shaft 11 of the drive motor 10 are clearance-matched so that the two can rotate relative to each other.

[0040] like Figure 1 and Figure 2 As shown, the first transmission shaft 31 and the hollow motor shaft 11 of the driving motor 10 can be connected through a primary gear set 32, so that the power of the driving motor 10 can be transmitted to the first transmission shaft 31 through the primary gear set 32. Figure 5 At the same time, Figure 1 As shown, the second transmission shaft 41 and the first transmission shaft 31 can be connected to each other through the secondary low-speed gear set 42 and the secondary high-speed gear set 43, so that the first transmission shaft 31 can transmit power to the second transmission shaft 41 through the secondary low-speed gear set 42 and the secondary high-speed gear set 43, as shown in FIG. Figure 5 As shown. Figure 1 and Figure 3 As shown, the second transmission shaft 41 is connected to the differential assembly 20 through a three-stage gear set 44, so that the second transmission shaft 41 can transmit power from the three-stage gear set 44 to the differential assembly 20. Figure 5 As shown, a three-stage deceleration effect can be achieved.

[0041] like Figure 1 and Figure 3As shown, the synchronizer 50 can be arranged on the second transmission shaft 41, and the synchronizer 50 is located between the secondary high-speed gear set 43 and the secondary low-speed gear set 42, so as to adjust the high-speed gear and the low-speed gear, so as to adapt to different working conditions. Figure 1 As shown, the synchronizer 50 may include a gear sleeve 51 that moves along the axial direction of the second transmission shaft 41 and a gear hub 52 that is transmission-connected to the second transmission shaft 41, and the gear hub 52 may be transferred to the second transmission shaft 41 through a spline, and the gear sleeve 51 and the gear hub 52 may be transmission-connected through a spline. The gear sleeve 51 includes at least two working positions on the path of axial movement along the second transmission shaft 41, one of which is that the gear sleeve 51 is transmission-connected to the secondary high-speed gear set 43, and the reduction ratio is small, so as to achieve high-speed and low-torque output, thereby adapting to conventional working conditions, and the other working position is that the gear sleeve 51 is transmission-connected to the secondary low-speed gear set 42, and the reduction ratio is large, so as to achieve low-speed and high-torque output, thereby adapting to the escape working condition. Of course, the gear sleeve 51 may also include an intermediate working position on the path of axial movement along the second transmission shaft 41, that is, the gear sleeve 51 may be disengaged from the transmission connection between the secondary low-speed gear set 42 and the secondary high-speed gear set 43.

[0042] like Figure 4 As shown, the first transmission shaft 31, the second transmission shaft 41 and the hollow motor shaft 11 are arranged in parallel, and the rotation centers of the first transmission shaft 31, the second transmission shaft 41 and the hollow motor shaft 11 are not colinear, so that the rotation centers of the first transmission shaft 31, the second transmission shaft 41 and the hollow motor shaft 11 are distributed in a triangular shape, thereby reducing the occupied space of the electric drive assembly and making its layout more compact.

[0043] In the electric drive assembly disclosed in the embodiments of the present application, by coaxially connecting the output half shaft 21 of the differential assembly 20 and the hollow motor shaft 11 of the drive motor 10 through the output half shaft 12, it can be ensured that under conditions such as emergency braking, the hollow motor shaft 11 of the drive motor 10 can move towards the output half shaft 12, reducing the deformation influence on the gear shaft system and achieving better NVH performance. At the same time, the first transmission shaft 31 is drivingly connected to the hollow motor shaft 11 of the drive motor 10 through a first-stage gear set 32, and the second transmission shaft 41 is drivingly connected to the first transmission shaft 31 through a second-stage high-speed gear set 43 and a second-stage low-speed gear set 42 respectively, and the second transmission shaft 41 is drivingly connected to the differential assembly 20 through a third-stage gear set 44. In addition, the synchronizer 50 is arranged on the second transmission shaft 41 with a relatively low rotational speed, and the synchronizer 50 is located between the second-stage high-speed gear set 43 and the second-stage low-speed gear set 42. By switching the gear sleeve 51 between the working positions of the second-stage high-speed gear set 43 and the second-stage low-speed gear set 42 respectively, the switching between the low-speed gear and the high-speed gear can be realized. Moreover, the first transmission shaft 31, the second transmission shaft 41, and the hollow motor shaft 11 are arranged in parallel, and the rotation centers of the first transmission shaft 31, the second transmission shaft 41, and the hollow motor shaft 11 are not collinear, so that the layout of the electric drive assembly can be made more compact.

[0044] Compared with the Y-type two-speed drive assembly, the electric drive assembly disclosed in the embodiments of the present application can reduce the use of parts such as transmission shafts, reduce costs, improve transmission efficiency, and at the same time, through three-stage deceleration, it is convenient to adjust the speed ratio. In addition, by arranging the first transmission shaft 31, the second transmission shaft 41, and the hollow motor shaft 11 in parallel and non-collinear, the occupied space of the electric drive assembly can be reduced, making its layout more compact.

[0045] In some embodiments, as Figure 1 shown, the first-stage gear set 32 may include a first-stage driving gear 321 drivingly connected to the hollow motor shaft 11 and a first-stage driven gear 322 drivingly connected to the first transmission shaft 31, and the first-stage driving gear 321 meshes with the first-stage driven gear 322 to realize the power transmission of the drive motor 10. At the same time, an axial retaining ring 3211 for the first-stage shaft may be arranged on the outer side of the hollow motor shaft 11 to axially limit the first-stage driving gear 321 through the axial retaining ring 3211 for the first-stage shaft. Optionally, an external spline may be arranged on the hollow motor shaft 11 of the drive motor 10, and an internal spline may be arranged on the first-stage driving gear 321, so that the first-stage driving gear 321 is assembled on the external spline of the hollow motor shaft 11 through the internal spline, and the first-stage driven gear 322 may be assembled on the first transmission shaft 31 through a spline, so as to realize the transmission of the power of the drive motor 10 to the first transmission shaft 31 through the first-stage driving gear 321 and the first-stage driven gear 322. In addition, as Figures 1 to 3As shown, a motor bearing 111 may be provided on the hollow motor shaft 11, and the motor bearing 111 may be fixed to the housing of the electric drive assembly to support the hollow motor shaft 11 and ensure the stability of the power output of the drive motor 10.

[0046] In some embodiments, as Figure 1 shown, the first transmission shaft 31 has two opposite ends. For the convenience of understanding, the two ends of the first transmission shaft 31 are respectively defined as the first end and the second end. Among them, the first-stage driven gear 322 is closer to the first end of the first transmission shaft 31 than the second end of the first transmission shaft 31, and a first bearing 311 is provided at the first end of the first transmission shaft 31, and a second bearing 312 is provided at the second end of the first transmission shaft 31. The first bearing 311 can be fixed to the housing of the electric drive assembly and the first transmission shaft 31 through two first bearing retaining rings 3111, and the second bearing 312 can be fixed to the first transmission shaft 31 through the first shaft shoulder 3121 of the first transmission shaft 31 and the second bearing retaining ring 3122. Optionally, in order to improve the transmission efficiency, the first bearing 311 can be a deep groove ball bearing, and the outer ring of the first bearing 311 can be fixed to the housing of the electric drive assembly through a hole retaining ring, and the inner ring of the first bearing 311 can be fixed to the first transmission shaft 31 through a shaft retaining ring, so that the first bearing 311 bears all the axial forces of the first transmission shaft 31, and the second bearing 312 can be a cylindrical roller bearing, and the inner ring of the second bearing 312 can be fixed to the first transmission shaft 31 through the first shaft shoulder 3121 of the first transmission shaft 31 and a shaft retaining ring.

[0047] In some embodiments, as Figure 1 shown, the second-stage low-speed gear set 42 may include a second-stage low-speed driving tooth portion 421 fixed to the first transmission shaft 31 and a second-stage low-speed driven gear 422 sleeved on the second transmission shaft 41. The second-stage low-speed driven gear 422 rotates relative to the second transmission shaft 41, the second-stage low-speed driven gear 422 meshes with the second-stage low-speed driving tooth portion 421, and the gear sleeve 51 can be in transmission connection with the second-stage low-speed driven gear 422, so that the first transmission shaft 31 can transmit power from the second-stage low-speed driving tooth portion 421 and the second-stage low-speed driven gear 422 to the synchronizer 50, and then from the synchronizer 50 to the second transmission shaft 41. Optionally, the second-stage low-speed driving tooth portion 421 can be integrally provided on the first transmission shaft 31, so that the second-stage low-speed driven gear 422 can mesh with the second-stage low-speed driving tooth portion 421, thereby realizing power transmission.

[0048] In some embodiments, as Figure 1As shown, a low-speed coupling tooth 4221 may be fixed to the secondary low-speed driven gear 422 by welding, so that the gear sleeve 51 may mesh with the low-speed coupling tooth 4221 to achieve power transmission from the secondary low-speed driven gear 422 to the synchronizer 50. At the same time, a low-speed limiting step may be provided on the low-speed coupling tooth 4221, so that the moving stroke of the gear sleeve 51 may be limited by the low-speed limiting step.

[0049] In some embodiments, Figure 1 As shown, one side of the gear hub 52 can abut against the second shaft shoulder 411 of the second transmission shaft 41, and a spacer sleeve 412 is sleeved on the second transmission shaft 41, and the spacer sleeve 412 is interference fit with the second transmission shaft 41, and the spacer sleeve 412 can be pressed against the other side of the gear hub 52, that is, the side of the gear hub 52 away from the second shaft shoulder 411. A low-speed needle roller bearing 4222 is assembled on the outer side of the spacer sleeve 412, and the secondary low-speed driven gear 422 is sleeved on the low-speed needle roller bearing 4222, so that the secondary low-speed driven gear 422 can rotate freely on the low-speed needle roller bearing 4222.

[0050] In some embodiments, Figure 1 As shown, a bearing stopper 4121 and a first gear stop ring 4122 for limiting the axial movement of the gear hub 52 may be sequentially provided on the side of the spacer sleeve 412 away from the gear hub 52, and a certain gap is provided between the bearing stopper 4121 and the secondary low-speed driven gear 422 to ensure that the secondary low-speed driven gear 422 can rotate smoothly on the low-speed needle roller bearing 4222.

[0051] In some embodiments, Figure 1 As shown, the secondary high-speed gear set 43 may include a secondary high-speed driving gear 431 drivingly connected to the first transmission shaft 31 and a secondary high-speed driven gear 432 sleeved on the second transmission shaft 41. The secondary high-speed driving gear 431 is fixed to the first transmission shaft 31 through the third shaft shoulder 313 and the second gear retaining ring 4311 of the first transmission shaft 31. The secondary high-speed driven gear 432 rotates relative to the second transmission shaft 41. The secondary high-speed driven gear 432 is meshed with the secondary high-speed driven gear 432. The gear sleeve 51 can be drivingly connected to the secondary high-speed driven gear 432, so that the first transmission shaft 31 can transmit power from the secondary high-speed driving gear 431 and the secondary high-speed driven gear 432 to the synchronizer 50, and then transmitted to the second transmission shaft 41 by the synchronizer 50. Optionally, the secondary high-speed driving gear 431 can be assembled on the first transmission shaft 31 through a spline, and the secondary high-speed driving gear 431 is axially limited and fixed by the third shaft shoulder 313 and the second gear retaining ring 4311 of the first transmission shaft 31, so that the secondary high-speed driven gear 432 can mesh with the secondary high-speed driving gear 431, thereby realizing power transmission.

[0052] In some embodiments,Figure 1 As shown in the figure, a high-speed needle roller bearing 4321 can be assembled on the second transmission shaft 41, and the second-stage high-speed driven gear 432 can be sleeved on the high-speed needle roller bearing 4321, so that the second-stage high-speed driven gear 432 can rotate freely on the high-speed needle roller bearing 4321. At the same time, a high-speed engaging tooth 4322 can be fixed on the second-stage high-speed driven gear 432 by welding, so that the power can be transmitted from the second-stage high-speed driven gear 432 to the synchronizer 50 through the engagement of the gear sleeve 51 with the high-speed engaging tooth 4322. And, a high-speed limit step can be provided on the high-speed engaging tooth 4322, so that the moving stroke of the gear sleeve 51 can be limited by the high-speed limit step.

[0053] It can be seen from the above embodiments that arranging the synchronizer 50 on the second transmission shaft 41 with a lower rotational speed and arranging both the second-stage high-speed driven gear 432 with a larger mass and the second-stage low-speed driven gear 422 on the second transmission shaft 41 can help reduce efficiency losses.

[0054] In some embodiments, as Figure 1 shown, a third bearing 413 and a fourth bearing 414 can be respectively arranged at both ends of the second transmission shaft 41, and the third bearing 413 and the fourth bearing 414 are respectively fixed on the housing of the electric drive assembly to realize the support of the second transmission shaft 41 and ensure the stability of the power transmission of the second transmission shaft 41.

[0055] In some embodiments, as Figure 1 shown, the synchronizer 50 may further include a slider 53 and a synchronizing ring 54. The slider 53 is located on the shifting fork of the synchronizer 50, and the slider 53 is pushed by the movement of the shifting fork. At the same time, the synchronizing ring 54 is located between the gear sleeve 51 and the gear hub 52. During shifting, the shifting fork pushes the slider 53, the slider 53 pushes the synchronizing ring 54, and the synchronizing ring 54 frictions with the gear hub 52 and the gear sleeve 51 to achieve speed synchronization. When the synchronization is completed, the gear sleeve 51 meshes with the high-speed engaging tooth 4322 or the low-speed engaging tooth 4221 to transmit power. It should be noted that the specific structure of the synchronizer 50 is similar to that of the traditional synchronizer and will not be elaborated herein.

[0056] In some embodiments, as Figure 1 and Figure 3 shown, the third-stage gear set 44 may include a third-stage driving tooth portion 441 fixed on the second transmission shaft 41 and a third-stage driven gear 442 connected to the differential assembly 20, and the third-stage driving tooth portion 441 meshes with the third-stage driven gear 442 to achieve power transmission. Optionally, the third-stage driving tooth portion 441 can be integrally provided on the second transmission shaft 41 so that the third-stage driving tooth portion 441 can mesh with the third-stage driven gear 442 to thereby achieve power transmission.

[0057] It should be noted that the differential assembly 20 can adopt a differential with an electronic differential lock or an ordinary differential, which is not limited herein.

[0058] The terms "first" and "second" etc. in the description, claims and the above drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the steps or units listed, but may include steps or units not listed.

[0059] The above description of the disclosed embodiments enables those skilled in the art to implement or use this application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electric drive assembly, characterized in that, Comprising: A driving assembly, the driving assembly includes a driving motor (10) and a differential assembly (20), and an output short half shaft (21) of the differential assembly (20) and a hollow motor shaft (11) of the driving motor (10) are coaxially connected through an output half shaft (12); A first transmission shaft (31), which is drivingly connected to the hollow motor shaft (11) of the driving motor (10) through a first-stage gear set (32); A second transmission shaft (41), which is drivingly connected to the first transmission shaft (31) through a second-stage low-speed gear set (42) and a second-stage high-speed gear set (43) respectively, and the second transmission shaft (41) is drivingly connected to the differential assembly (20) through a third-stage gear set (44); A synchronizer (50), which is arranged on the second transmission shaft (41), and the synchronizer (50) is located between the second-stage high-speed gear set (43) and the second-stage low-speed gear set (42). The synchronizer (50) includes a gear sleeve (51) that can move axially along the second transmission shaft (41) and a gear hub (52) that is drivingly connected to the second transmission shaft (41). The gear sleeve (51) is drivingly connected to the gear hub (52). At least two working positions are included in the moving path of the gear sleeve (51). The two working positions of the gear sleeve (51) are respectively drivingly connected to the second-stage high-speed gear set (43) and the second-stage low-speed gear set (42); The first transmission shaft (31), the second transmission shaft (41) and the hollow motor shaft (11) are arranged in parallel, and the rotation centers of the first transmission shaft (31), the second transmission shaft (41) and the hollow motor shaft (11) are not collinear.

2. The electric drive assembly according to claim 1, wherein, The first-stage gear set (32) includes a first-stage driving gear (321) drivingly connected to the hollow motor shaft (11) and a first-stage driven gear (322) drivingly connected to the first transmission shaft (31). The first-stage driving gear (321) meshes with the first-stage driven gear (322). A first shaft retaining ring (3211) is arranged on the outer side of the hollow motor shaft (11), and the first shaft retaining ring (3211) is used for axially limiting the first-stage driving gear (321).

3. The electric drive assembly according to claim 2, wherein, The first transmission shaft (31) has a first end and a second end arranged oppositely. The first-stage driven gear (322) is closer to the first end of the first transmission shaft (31) than the second end of the first transmission shaft (31). A first bearing (311) is arranged at the first end of the first transmission shaft (31). The first bearing (311) is fixed to the housing of the electric drive assembly and the first transmission shaft (31) respectively through two first bearing retaining rings (3111). A second bearing (312) is arranged at the second end of the first transmission shaft (31). The second bearing (312) is fixed to the first transmission shaft (31) through a first shaft shoulder (3121) and a second bearing retaining ring (3122) of the first transmission shaft (31).

4. The electric drive assembly according to claim 1, wherein, The second-stage low-speed gear set (42) includes a second-stage low-speed driving tooth part (421) fixed to the first transmission shaft (31) and a second-stage low-speed driven gear (422) sleeved on the second transmission shaft (41). The second-stage low-speed driven gear (422) rotates relative to the second transmission shaft (41), the second-stage low-speed driven gear (422) meshes with the second-stage low-speed driving tooth part (421), and the gear sleeve (51) is used for driving connection with the second-stage low-speed driven gear (422).

5. The electric drive assembly according to claim 4, characterized in that, A low-speed engaging tooth (4221) for meshing with the gear sleeve (51) is fixed on the second-stage low-speed driven gear (422), and a low-speed limiting step for limiting the moving stroke of the gear sleeve (51) is arranged on the low-speed engaging tooth (4221).

6. The electric drive assembly according to claim 4, characterized in that One side of the gear hub (52) abuts against the second shaft shoulder (411) of the second transmission shaft (41). A spacer sleeve (412) is sleeved on the second transmission shaft (41). The spacer sleeve (412) is in interference fit with the second transmission shaft (41), and the spacer sleeve (412) presses against the other side of the gear hub (52). The second-stage low-speed driven gear (422) is rotatably sleeved on the spacer sleeve (412) through a low-speed needle bearing (4222).

7. The electric drive assembly according to claim 6, wherein, A bearing retaining plate (4121) and a first gear snap ring (4122) for limiting the axial movement of the gear hub (52) are sequentially arranged on the side of the spacer sleeve (412) away from the gear hub (52).

8. The electric drive assembly according to claim 1, characterized in that, The second-stage high-speed gear set (43) includes a second-stage high-speed driving gear (431) drivingly connected with the first transmission shaft (31) and a second-stage high-speed driven gear (432) sleeved on the second transmission shaft (41). The second-stage high-speed driving gear (431) is fixed to the first transmission shaft (31) through the third shaft shoulder (313) of the first transmission shaft (31) and a second gear snap ring (4311). The second-stage high-speed driven gear (432) rotates relative to the second transmission shaft (41), the second-stage high-speed driven gear (432) meshes with the second-stage high-speed driving gear (431), and the gear sleeve (51) is used for driving connection with the second-stage high-speed driven gear (432).

9. The electric drive assembly according to claim 8, wherein, The second-stage high-speed driven gear (432) is rotatably sleeved on the second transmission shaft (41) through a high-speed needle bearing (4321). A high-speed engaging tooth (4322) for meshing with the gear sleeve (51) is fixed on the second-stage high-speed driven gear (432), and a high-speed limiting step for limiting the moving stroke of the gear sleeve (51) is arranged on the high-speed engaging tooth (4322).

10. The electric drive assembly according to any one of claims 1 to 9, characterized in that The third-stage gear set (44) includes a third-stage driving tooth part (441) fixed to the second transmission shaft (41) and a third-stage driven gear (442) connected with the differential assembly (20). The third-stage driving tooth part (441) meshes with the third-stage driven gear (442).

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