Electric drive device and vehicle

Abstract

This disclosure relates to an electric drive device (1) comprising: a motor (100) including a motor shaft (10) rotating about a rotation axis (X); a gearbox (200) connected to the motor (100); the gearbox (200) including an input shaft (20) rotatably connected to the motor shaft (10) via a connection region (2) between them. A centering region (3) is further provided between the motor shaft (10) and the input shaft (20), and the centering region (3) includes a tapered region (3a) at which the input shaft (20) and the motor shaft (10) abut against each other when the electric drive device (1) rotates forward. This disclosure also relates to a vehicle including the above-described electric drive device (1).

Description

Technical Field

[0001] This disclosure relates to an electric drive system. This disclosure also relates to vehicles including such an electric drive system. Background Technology

[0002] The electric drive system of a vehicle includes an electric motor for driving the vehicle and transmission components such as a gearbox. The motor shaft and the input shaft of the gearbox are rotatably connected to transmit torque from the motor to the gearbox. When driving the vehicle, the motor shaft and the input shaft of the gearbox rotate at high speed, and their coaxiality needs to be good enough to reduce vibration and improve transmission efficiency.

[0003] In existing electric drive devices, the motor shaft and input shaft are aligned with each other via a cylindrical guide region to achieve coaxial arrangement. Within this cylindrical guide region, a certain clearance is still required between the motor shaft and input shaft to facilitate assembly. However, this clearance is not conducive to ensuring the coaxiality of the motor shaft and input shaft.

[0004] Therefore, there is a need for an electric drive device in which the motor shaft of the electric motor and the input shaft of the gearbox are well coaxial with each other to improve the NVH (noise, vibration, and harshness) performance of the vehicle. Summary of the Invention

[0005] Therefore, this disclosure aims to solve the above-mentioned problems, and its object is to provide an electric drive device and a vehicle including such an electric drive device. According to the electric drive device of this disclosure, the motor shaft of the motor and the input shaft of the gearbox are well coaxial with each other, improving the NVH performance of the vehicle without increasing assembly difficulty.

[0006] The objective is achieved by an electric drive device according to an embodiment of the present disclosure, the electric drive device comprising: a motor including a motor shaft rotating about a rotation axis; and a gearbox connected to the motor, the gearbox including an input shaft rotatably connected to the motor shaft via a connection region between them. A centering region is further provided between the motor shaft and the input shaft, and the centering region includes a tapered region, wherein when the electric drive device rotates forward, the input shaft and the motor shaft abut against each other at the tapered region.

[0007] One objective of this disclosure is to provide an electric drive device in which the motor shaft and the input shaft of the gearbox are well coaxial with each other without increasing assembly difficulty. The electric drive device according to this disclosure includes a tapered centering region between the motor shaft and the input shaft. When the electric drive device rotates forward, i.e., when the vehicle is moving forward, the meshing of the gears in the gearbox generates an axial force pointing towards the motor shaft, causing the input shaft to move axially towards the motor shaft and abut against it at the tapered region, thereby ensuring good coaxiality between the motor shaft and the input shaft. Furthermore, this configuration of the tapered centering region eliminates the need for precisely coaxial arrangement of the motor shaft and the input shaft during assembly, thus reducing assembly difficulty.

[0008] The electric drive device according to this disclosure may also have one or more of the following features, individually or in combination.

[0009] According to an optional embodiment of this disclosure, the centering region further includes a cylindrical region. This cylindrical region allows the motor shaft and input shaft to remain coaxial with a certain degree of precision even when the input shaft and motor shaft are not abutting each other in the tapered region, for example, when the electric drive is reversing (corresponding to vehicle reversing).

[0010] According to one embodiment of this disclosure, the motor shaft includes a central hole, which comprises a tapered portion and a cylindrical portion. The input shaft includes a tapered section and a cylindrical section inserted into the central hole. The tapered section mates with the tapered portion to form the tapered region, and the cylindrical section mates with the cylindrical portion to form the cylindrical region. Thus, when the electric drive device rotates forward, the tapered section of the input shaft abuts against the tapered portion of the motor shaft.

[0011] According to one embodiment of this disclosure, the input shaft further includes an external spline, and the central hole of the motor shaft includes an internal spline. The external spline and the internal spline mate to form a connection area. The external spline is located at the axial end of the input shaft, and the tapered section is closer to the external spline than the cylindrical section. The depth of the internal spline within the central hole is greater than that of the tapered and cylindrical sections, and the cylindrical section is closer to the opening of the central hole. The input shaft and the motor shaft are rotatably connected through the spline engagement at the connection area, meaning they rotate substantially synchronously.

[0012] According to one embodiment of this disclosure, the input shaft further includes a clearance groove disposed between the tapered section and the cylindrical section. This clearance groove prevents interference between the connection between the tapered and cylindrical sections and the central hole of the motor shaft, thus avoiding interference with the coaxiality of the motor shaft and the input shaft.

[0013] According to one embodiment of this disclosure, the electric drive device further includes a first bearing, a second bearing, and a third bearing. The first bearing supports the input shaft at an axial end opposite to the coupling region, the second bearing supports the motor shaft at the coupling region and / or the centering region, and the third bearing supports the motor shaft at an axial end opposite to the coupling region. In other words, the electric drive device supports the input shaft and the motor shaft via three bearings.

[0014] According to one embodiment of this disclosure, the cone angle of the tapered region is configured such that when the electric drive device rotates forward, the radial load borne by the first bearing is less than the radial load borne by the second bearing.

[0015] According to one embodiment of this disclosure, the electric drive device further includes an adjusting shim disposed between the first bearing and the housing of the electric drive device to adjust the axial clearance between them.

[0016] According to one embodiment of this disclosure, the electric drive device further includes a corrugated shim disposed between the second bearing and the housing of the electric drive device to control the axial movement of the motor shaft.

[0017] According to one embodiment of this disclosure, the electric drive device further includes two retaining rings respectively mounted to the housing of the electric drive device and the motor shaft on both axial sides of the third bearing to fix the third bearing in place in the axial direction.

[0018] According to one embodiment of this disclosure, the cone angle of the cone region is greater than or equal to 16°.

[0019] According to one embodiment of this disclosure, the tapered and cylindrical sections of the input shaft have a surface-hardened layer. Exemplarily, the input shaft is first surface-hardened by heat treatment, and a certain thickness of surface-hardened layer is retained after finishing.

[0020] According to one embodiment of this disclosure, the tapered and cylindrical bore sections of the motor shaft may also have a surface hardening layer.

[0021] According to one embodiment of this disclosure, the tapered section of the input shaft is provided with one or more grooves extending along the generatrix direction of the tapered section. These grooves allow lubricating oil to enter the tapered centering region and lubricate the tapered mating surfaces of the input shaft and the motor shaft.

[0022] According to one embodiment of this disclosure, at least one of the first bearing, the second bearing, and the third bearing is a deep groove ball bearing.

[0023] According to one embodiment of this disclosure, the input shaft includes a central hole, the central hole including a tapered portion and a cylindrical portion, and the motor shaft includes a tapered segment and a cylindrical segment inserted into the central hole, wherein the tapered segment cooperates with the tapered portion to form the tapered region, and the cylindrical segment cooperates with the cylindrical portion to form the cylindrical region.

[0024] This disclosure also relates to a vehicle that includes an electric drive device as described above. Attached Figure Description

[0025] The above and other features and advantages of this disclosure will become more apparent from the following detailed description of exemplary embodiments taken in conjunction with the accompanying drawings, which are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way. The following drawings are not intentionally drawn to scale with actual dimensions; their focus is on illustrating the gist of this disclosure.

[0026] Figure 1 A cross-sectional view of an electric drive device according to the present disclosure is shown.

[0027] Figure 2 A cross-sectional view of the connection region and the centering region of the motor shaft and the input shaft of the gearbox of the electric motor according to the present disclosure is shown.

[0028] Figure 3 The input shaft of the gearbox is shown.

[0029] Figure 4 A partial sectional view of the motor shaft is shown.

[0030] Figure 5 and Figure 6 The bearings used to support the motor shaft and input shaft are shown in detail in an enlarged sectional view. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings.

[0032] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The use of words such as “a,” “an,” or “the” in this patent application specification and claims does not indicate a quantity limitation, but rather indicates the presence of at least one. Words such as “comprising” or “including” mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents. Words such as “connected” or “linked” are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as “up,” “down,” “left,” and “right” are used only to indicate relative positional relationships, which may change accordingly when the absolute position of the described object changes. The terms “axial” and “axial direction” refer to the direction of the motor’s rotation axis X, and “radial” and “radial direction” refer to the direction perpendicular to the motor’s rotation axis X.

[0033] For ease of description, the accompanying drawings of this disclosure have correspondingly simplified or omitted components commonly used in the art, such as external connecting lines and other components unrelated to the description of this disclosure. These omitted or simplified components do not affect a person skilled in the art's understanding of the content of this disclosure.

[0034] Figure 1 A partial cross-sectional view of an electric drive device 1 according to an exemplary embodiment of the present disclosure is shown.

[0035] like Figure 1 As shown, the electric drive device 1 includes a motor 100 and a gearbox 200. The motor 100 includes a rotor and a stator. The motor shaft is located at the center of the rotor and rotates together with the rotor 110 about the rotation axis X. The gearbox 200 is integrated with the motor 100 and connected to the motor 100. Specifically, the gearbox 200 includes an input shaft 20, which is coaxial with the motor shaft 10 of the motor 100 and rotatably connected through a connection area 2 between them, so that there is no relative rotation between the motor shaft 10 and the input shaft 20. In other words, the rotation of the motor shaft 10 about the rotation axis X drives the input shaft 20 to rotate together about the rotation axis X, thereby realizing the torque transmission from the motor 100 to the gearbox 200.

[0036] Please refer to Figure 2Specifically, the connection between the motor shaft 10 and the input shaft 20 may include a connection region 2 and a centering region 3. The centering region 3 is particularly a radial centering region, used to ensure that the input shaft 20 and the motor shaft 10 are coaxial with each other. The connection region 2 and the centering region 3 are arranged adjacent to each other in the axial direction. This configuration allows for convenient machining of the corresponding connection and centering regions on the motor shaft 10 and the input shaft 20, and facilitates simplified assembly between the motor shaft 10 and the input shaft 20, thereby saving design, manufacturing, and assembly costs and improving cost-effectiveness.

[0037] The rotational connection between the motor shaft 10 and the input shaft 20 is achieved by the first connecting member of the motor shaft 10 and the second connecting member of the input shaft 20 being connected to each other in the connection area 2. The connection area of ​​the first connecting member and the second connecting member is located at the axial end of the motor 100. (Reference) Figures 3-4 In the illustrated embodiment, the motor shaft 10 includes a first central hole 11, and an internal spline 14 is disposed at a deeper axial position within the first central hole 11, forming a first connecting member of the motor shaft 10. The input shaft 20 has an external spline 21 on its outer surface at its axial end, forming a second connecting member of the input shaft 20. In the assembly configuration, the input shaft 20 is inserted into the first central hole 11 of the motor shaft 10, and the external spline 21 and the internal spline 14 mesh with each other, thereby rotatably connecting the motor shaft 10 and the input shaft 20 together. The meshing area of ​​the external spline 21 and the internal spline 14 forms the connection area 2 of the motor shaft 10 and the input shaft 20.

[0038] The coaxial arrangement of the motor shaft 10 and the input shaft 20 is ensured by the alignment region 3 between them. The alignment region 3 includes a tapered region 3a and a cylindrical region 3b. (See reference) Figures 2-4 In the illustrated embodiment, the first central hole 11 of the motor shaft 10 further includes a tapered hole portion 12 and a cylindrical hole portion 13. In the axial direction, the cylindrical hole portion 13 is closer to the opening of the central hole 11, while the tapered hole portion 12 is located between the cylindrical hole portion 13 and the internal spline 14. Correspondingly, the input shaft 20 includes a tapered section 22 and a cylindrical section 23. In the axial direction, the tapered section 22 is closer to the external spline 21. In the assembly configuration, the input shaft 20 is inserted into the first central hole 11 of the motor shaft 10, and the tapered section 22 and the tapered hole portion 12 cooperate to form a tapered region 3a, while the cylindrical section 23 and the cylindrical hole portion 13 cooperate to form a cylindrical region 3b.

[0039] refer to Figure 1 and Figure 3The input shaft 20 has a gear section 26, which is arranged in the gearbox 200 and meshes with the intermediate gear or output shaft gear of the gearbox 200 to transmit torque and regulate speed. The gear section 26 has a helical tooth structure, and its gear rotation direction is configured such that when the electric drive device 1 rotates forward, that is, when the vehicle is moving forward, the gear meshing in the gearbox 200 generates an axial force pointing towards the motor shaft 10, pushing the input shaft 20 to move axially toward the motor shaft 10; when the electric drive device 1 rotates in reverse, that is, when the vehicle is reversing, the gear meshing in the gearbox 200 generates an axial force pointing towards the gearbox 200, pushing the input shaft 20 to move axially away from the motor shaft 10.

[0040] Therefore, when the electric drive unit 1 rotates forward, the input shaft 20 moves axially, causing the tapered section 22 to press against the tapered bore 12. The input shaft 20 and the motor shaft 10 abut against each other at the tapered region 3a of the centering region 3, that is, the outer surface of the tapered section 22 contacts the inner surface of the tapered bore 12. As a result, the radial clearance between the input shaft 20 and the motor shaft 10 is reduced or even eliminated, and their coaxiality is improved by this tapered centering region 3a.

[0041] When the electric drive unit 1 reverses, the input shaft 20 moves axially away from the motor shaft 10, so that the input shaft 20 and the motor shaft 10 no longer abut against each other in the tapered region 3a, that is, the tapered section 22 disengages from the tapered bore 12. In the cylindrical region 3b, the cylindrical section 23 remains within the cylindrical bore 13. Therefore, when the electric drive unit 1 reverses, the coaxiality between the input shaft 20 and the motor shaft 10 is maintained by this cylindrical centering region 3b without significantly decreasing.

[0042] In summary, the electric drive device 1 according to this disclosure improves the coaxiality between the input shaft 20 and the motor shaft 10 through the tapered centering region 3a during forward rotation, which occupies the majority of the operating time. During reverse rotation, it maintains coaxiality through the cylindrical centering region 3b, similar to a conventional electric drive device 1 with only a cylindrical centering region. Therefore, the electric drive device 1 according to this disclosure improves the overall coaxiality between the input shaft 20 and the motor shaft 10, improves the vehicle's NVH performance, and increases torque transmission efficiency.

[0043] In addition, refer to Figure 3 The input shaft 20 also has a clearance groove 24 between the tapered section 22 and the cylindrical section 23. The clearance groove 24 eliminates the rounded transition between the tapered section 22 and the cylindrical section 23. When the input shaft 20 moves axially toward the motor shaft 10, the clearance groove 24 prevents this rounded transition from interfering with the center hole 11, thus preventing the input shaft 20 from misaligning with the motor shaft 10. Alternatively, this clearance groove can also be provided between the tapered hole portion 12 and the cylindrical hole portion 13 of the motor shaft 10.

[0044] Further reference Figure 3 The tapered section 22 of the input shaft 20 is also provided with one or more grooves 25 extending along the generatrix of the tapered section 22. When the input shaft 20 and the motor shaft 10 abut against each other, these grooves 25 allow lubricating oil to flow between the outer surface of the tapered section 22 and the inner surface of the tapered bore 12 to lubricate the input shaft 20 and the motor shaft 10.

[0045] Furthermore, the tapered section 22 and cylindrical section 23 of the input shaft 20, as well as the tapered bore section 12 and cylindrical bore section 13 of the motor shaft 10, all have a surface-hardened layer. Exemplarily, the input shaft 20 can be heat-treated after rough machining to form the surface-hardened layer. Then, the input shaft 20 is finish-machined to form the tapered section 22 and cylindrical section 23, without completely removing the surface-hardened layer. That is, the finished input shaft 20 still has a surface-hardened layer of a certain thickness at the tapered section 22 and cylindrical section 23.

[0046] When the electric drive unit 1 is in operation, the assembly of the input shaft 20 and the motor shaft 10 rotates about the rotation axis X, and needs to bear load in both the axial and radial directions. In the illustrated embodiment, the electric drive unit 1 includes three bearings B1, B2 and B3 to support the assembly of the input shaft 20 and the motor shaft 10 within the housing.

[0047] refer to Figure 1 One axial end of the input shaft 20 is located at the connection area 2, while the other axial end is opposite to the connection area 2 and supported by a first bearing B1, which can be mounted on the housing of the electric drive device. (Continue to refer to...) Figure 1 One axial end of the motor shaft 10 is located in the connection area 2, connected to and centered with the input shaft 20, and the second bearing B2 supports the motor shaft 10 in the centering area 3. Optionally, the second bearing B2 may also be located in the connection area 2. The other axial end of the motor shaft 10 is opposite to the connection area 2 and supported by a third bearing B3, which may also be located on the housing of the electric drive device.

[0048] Of these three bearings, the third bearing, B3, has a fixed position in the axial direction. For example... Figure 6 As shown, the electric drive unit 1 includes two retaining rings 6 mounted axially to the housing of the electric drive unit 1 and the motor shaft 10 on both sides of the third bearing B3, for axially fixing the third bearing B3. The first bearing B1 and the second bearing B2 can move a certain distance in the axial direction. (Reference) Figure 5 An adjusting shim 4 is arranged between the first bearing B1 and the housing of the electric drive device 1 to adjust the axial clearance between them. (Reference) Figure 5The electric drive unit 1 also includes a corrugated shim 5 arranged between the second bearing B2 and the housing of the electric drive unit 1, for adjusting the axial clearance between them. The adjusting shim 4 can control the axial movement of the input shaft 20, while the corrugated shim 5 can control the axial movement of the motor shaft 10.

[0049] The first bearing B1, the second bearing B2, and the third bearing B3 can each withstand certain axial and radial loads. These three bearings collectively support the input shaft 20 and the motor shaft 10. The load distribution across the first bearing B1, the second bearing B2, and the third bearing B3 can be adjusted by changing the cone angle of the conical region 3a. The cone angle of the conical region 3a is the angle formed by the generatrix direction of the conical segment 22 and the direction of the rotation axis X.

[0050] When the electric drive device 1 according to this disclosure rotates forward, the tapered section 22 of the input shaft 20 abuts against the tapered bore 12 of the motor shaft 10, and the direction of the force between them is perpendicular to the generatrix direction of the tapered section 22. In particular, when the electric drive device 1 rotates forward, the input shaft 20 is subjected to an axial force pointing towards the motor shaft 10. This axial force is balanced by the axial component of the aforementioned force. That is, the axial force on the input shaft 20 generated by the gear meshing in the gearbox 200 is entirely borne by the motor shaft 10, and the first bearing B1 no longer bears the axial load.

[0051] Furthermore, the radial load on the first bearing B1 and the second bearing B2 can be adjusted by changing the cone angle of the tapered region 3a. Preferably, the cone angle is set such that the radial load on the first bearing B1 is less than the radial load on the second bearing B2. It is particularly advantageous to set the cone angle of the tapered region 3a to be greater than or equal to 16°. This cone angle setting allows the radial load on the first bearing B1 to be as small as possible when the electric drive unit 1 rotates forward, while the larger radial load is borne by the second bearing B2. In this case, the load borne by the first bearing B1 is as small as possible, so that a smaller bearing can be used as the first bearing B1. Accordingly, more space can be provided in the gearbox 200 for the use of deep groove ball bearings on the intermediate shaft, instead of less efficient tapered roller bearings, thereby improving the overall transmission efficiency of the gearbox 200.

[0052] The accompanying drawings illustrate an embodiment in which the input shaft 20 is inserted into the motor shaft 10. It is conceivable that the motor shaft 10 could also be inserted into the input shaft 20. That is, the input shaft 20 includes a central hole comprising a tapered portion, a cylindrical portion, and an internal spline; the motor shaft 10 includes a tapered section, a cylindrical section, and an external spline that are inserted into the central hole. The tapered section mates with the tapered portion to form a tapered centering region, the cylindrical section mates with the cylindrical portion to form a cylindrical centering region, and the internal spline and external spline mate to form a connection region.

[0053] According to another aspect of this disclosure, a vehicle is proposed that includes the electric drive unit as described above. The vehicle can be an electrified vehicle, such as a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a range-extended electric vehicle (REEV), or a fuel cell electric vehicle (FCEV). The vehicle can also be a hydrogen fuel cell vehicle.

[0054] Certain features, structures, or characteristics in one or more embodiments of this disclosure may be appropriately combined.

[0055] The foregoing description is illustrative of the present disclosure and should not be construed as limiting it. While several exemplary embodiments of the present disclosure have been described, those skilled in the art will readily understand that many modifications may be made to the exemplary embodiments without departing from the novel teachings and advantages of the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure as defined in the claims. It should be understood that the foregoing description is illustrative of the present disclosure and should not be construed as limiting it to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of this disclosure.

Claims

1. An electric drive device (1), comprising: The motor (100) includes a motor shaft (10) that rotates about a rotation axis (X). A gearbox (200) is connected to the motor (100). The gearbox (200) includes an input shaft (20) that is rotatably connected to the motor shaft (10) via a connection area (2) between them. The feature is that a centering region (3) is provided between the motor shaft (10) and the input shaft (20), and the centering region (3) includes a conical region (3a). When the electric drive device (1) rotates forward, the input shaft (20) and the motor shaft (10) abut against each other at the conical region (3b).

2. The electric drive device (1) according to claim 1, wherein, The centering region (3) also includes a cylindrical region (3b).

3. The electric drive device (1) according to claim 2, wherein, The motor shaft (10) includes a central hole (11), which includes a tapered hole portion (12) and a cylindrical hole portion (13). The input shaft (20) includes a tapered section (22) and a cylindrical section (23) inserted into the central hole (11), wherein the tapered section (22) cooperates with the tapered hole portion (12) to form the tapered region (3a), and the cylindrical section (23) cooperates with the cylindrical hole portion (13) to form the cylindrical region (3b).

4. The electric drive device (1) according to claim 3, wherein, The input shaft (20) also includes an external spline (21), and the center hole (11) of the motor shaft (10) includes an internal spline (14). The external spline (21) and the internal spline (14) cooperate to form the connection area (2). Wherein, the external spline (21) is located at the axial end of the input shaft (20), and the tapered segment (22) is closer to the external spline (21) than the cylindrical segment (23), and The internal spline (14) is deeper in the central hole (11) than the conical hole (12) and the cylindrical hole (13), and the cylindrical hole (13) is closer to the opening of the central hole (11).

5. The electric drive device (1) according to claim 3 or 4, wherein, The input shaft (20) also includes a clearance groove (24) arranged between the tapered section (22) and the cylindrical section (23).

6. The electric drive device (1) according to claim 3 or 4, wherein, The electric drive device (1) further includes a first bearing (B1), a second bearing (B2) and a third bearing (B3), wherein the first bearing (B1) supports the input shaft (20) at the axial end opposite to the connection area (2), the second bearing (B2) supports the motor shaft (10) at the connection area (2) and / or the centering area (3), and the third bearing (B3) supports the motor shaft (10) at the axial end opposite to the connection area (2).

7. The electric drive device (1) according to claim 6, wherein, The cone angle of the conical region (3a) is set such that when the electric drive device (1) rotates forward, the radial load borne by the first bearing (B1) is less than the radial load borne by the second bearing (B2).

8. The electric drive device (1) according to claim 6, wherein, The electric drive device (1) further includes an adjusting shim (4) which is arranged between the first bearing (B1) and the housing of the electric drive device (1) to adjust the axial clearance between them.

9. The electric drive device (1) according to claim 7 or 8, wherein, The electric drive device (1) further includes a wave-shaped shim (5) arranged between the second bearing (B2) and the housing of the electric drive device (1) to control the axial movement of the motor shaft (10).

10. The electric drive device (1) according to claim 7 or 8, wherein, The electric drive device (1) further includes two snap rings (6) respectively installed on the housing of the electric drive device (1) and the motor shaft (10) on both sides of the third bearing (B3) to fix the third bearing (B3) in the axial direction.

11. The electric drive device (1) according to claim 7 or 8, wherein, The cone angle of the cone region (3b) is greater than or equal to 16°.

12. The electric drive device (1) according to claim 3 or 4, wherein, The tapered section (22) and cylindrical section (23) of the input shaft (20) have a surface hardening layer.

13. The electric drive device (1) according to claim 3 or 4, wherein, The tapered section (22) of the input shaft (20) is provided with one or more grooves (25) extending along the generatrix of the tapered section (22).

14. The electric drive device (1) according to claim 6, wherein, At least one of the first bearing (B1), the second bearing (B2), and the third bearing (B3) is a deep groove ball bearing.

15. The electric drive device (1) according to claim 2, wherein, The input shaft (20) includes a central hole, which comprises a tapered portion and a cylindrical portion. The motor shaft (10) includes a tapered section and a cylindrical section inserted into the central hole, wherein the tapered section cooperates with the tapered hole to form the tapered region (3a), and the cylindrical section cooperates with the cylindrical hole to form the cylindrical region (3b).

16. A vehicle, characterized in that, The vehicle includes an electric drive unit (1) according to any one of claims 1 to 15.

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