Electric drive system and vehicle

Abstract

The electric drive system comprises a first shaft and a second shaft, the first shaft comprises a first shaft section and a second shaft section, the second shaft is provided with an inner hole, the inner hole comprises a first hole section and a second hole section, the first shaft section is arranged in the first hole section in a key fit mode, and the second shaft section is arranged in the second hole section in a key fit mode. The second shaft section is arranged in the second hole section in an interference fit mode so that radial centering limiting of the first shaft and the second shaft can be achieved. According to the electric drive system, high-speed unstable force caused when a spline transmits torque is improved, the situation that a high-speed shafting is unstable and vibrates is avoided, and the rotating speed range of the motor is widened.

Description

Technical Field

[0001] The present disclosure relates to the field of transmission technology, and in particular, to an electric drive system and a vehicle. Background Art

[0002] The automotive electric drive is one of the core components of electric vehicles, which mainly includes two parts: the motor and the reducer. The output shaft of the motor and the input shaft of the reducer are usually connected by splines, but this transmission method has the problem of unstable force, that is, the contact areas of different splines are asymmetric. When the spline shaft rotates, the splines will move up and down and rub, making the running rotor prone to instability and vibration, which cannot meet the use requirements of high-speed rotation of the electric drive. Utility Model Content

[0003] The present disclosure aims to solve one of the technical problems in the related art at least to some extent.

[0004] To this end, an embodiment of the present disclosure proposes an electric drive system, which improves the high-speed unstable force caused by the spline transmitting torque, avoids high-speed shaft system instability and vibration, and is conducive to increasing the speed of the motor.

[0005] The disclosed embodiment of the present disclosure also proposes a vehicle including the above-mentioned electric drive system.

[0006] The electric drive system of the embodiment of the present disclosure includes:

[0007] a first shaft, the first shaft comprising a first shaft segment and a second shaft segment;

[0008] The second shaft is provided with an inner hole, the inner hole comprises a first hole section and a second hole section, the first shaft section is key-fitted in the first hole section, and the second shaft section is interference-fitted in the second hole section.

[0009] In some embodiments, at least a portion of the second shaft segment is closer to the free end of the first shaft than the first shaft segment.

[0010] In some embodiments, there are two second shaft segments, one of which is a large diameter segment with a larger radial size, and the other is a small diameter segment with a smaller radial size, and the first shaft segment is arranged between the large diameter segment and the small diameter segment.

[0011] In some embodiments, the radial dimension of the first shaft segment is smaller than the radial dimension of the large diameter segment, and the radial dimension of the first shaft segment is larger than the radial dimension of the small diameter segment.

[0012] In some embodiments, in the axial direction along the first shaft, the length dimension of the first shaft segment is greater than the length dimension of any one of the large diameter segment and the small diameter segment.

[0013] In some embodiments, the length dimension of any one of the large diameter segment and the small diameter segment does not exceed one third of the length dimension of the first shaft segment;

[0014] And / or, the length dimension of the large diameter segment is consistent with the length dimension of the small diameter segment.

[0015] In some embodiments, the cross-section of the first shaft segment and the cross-section of the second shaft segment are both circular surfaces.

[0016] In some embodiments, the first shaft is provided with an annular end face, and the annular end face is used to abut against the end face of the second shaft on the circumferential side of the inner hole to achieve axial limitation between the first shaft and the second shaft.

[0017] In some embodiments, a motor and a reducer are included, the motor includes a motor shaft, the motor shaft forms the first shaft, and the reducer includes an input shaft, the input shaft forms the second shaft.

[0018] The vehicle of the disclosed embodiment includes an electric drive system as described in any of the above embodiments.

[0019] Beneficial effects: The electric drive system and vehicle of the disclosed embodiments improve the high-speed unstable force caused by the spline transmitting torque, avoid the instability and vibration of the high-speed shaft system, are beneficial to improving the speed range of the motor, and meet the use needs of the high-speed trend of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A partial cross-sectional view of the electric drive system of the present disclosure embodiment Figure 1 .

[0021] Figure 2 A partial cross-sectional view of the electric drive system of the present disclosure embodiment Figure 2 .

[0022] Figure 3 It is a cross-sectional schematic diagram of the electric drive system of an embodiment of the present disclosure.

[0023] Figure 4 It is a partial structural schematic diagram of a vehicle according to an embodiment of the present disclosure.

[0024] Reference numerals:

[0025] First shaft 1; first shaft section 11; second shaft section 12; large diameter section 121; small diameter section 122; annular end surface 13;

[0026] Second shaft 2; inner hole 21; first hole section 211; second hole section 212; large hole section 2121; small hole section 2122;

[0027] Motor 3; motor housing 31; first bearing 32; elastic member 33;

[0028] Speed ​​reducer 4; first end cover 41; second end cover 42; second bearing 43; third bearing 44; gasket 45;

[0029] Rotor core 5. DETAILED DESCRIPTION

[0030] Embodiments of the present disclosure are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present disclosure, but should not be understood as limiting the present disclosure.

[0031] like Figure 1 As shown, the electric drive system of the embodiment of the present disclosure includes a first shaft 1 and a second shaft 2 .

[0032] The first shaft 1 includes a first shaft section 11 and a second shaft section 12. For example, Figure 1 As shown, the first shaft 1 may be a round shaft, the first shaft segment 11 and the second shaft segment 12 may both be disposed at the right end of the first shaft 1 , and the first shaft segment 11 and the second shaft segment 12 may both be integrally formed on the first shaft 1 .

[0033] The first shaft section 11 may be provided with only one, and the outer peripheral side of the first shaft section 11 may be integrally formed with an external spline, and multiple external splines may be provided, and the multiple external splines may be arranged at intervals along the circumference of the first shaft section 11. The second shaft section 12 may be an optical axis, and the second shaft section 12 may be provided with only one.

[0034] The second shaft 2 is provided with an inner hole 21, and the inner hole 21 includes a first hole section 211 and a second hole section 212. The first shaft section 11 is key-fitted in the first hole section 211, and the second shaft section 12 is interference-fitted in the second hole section 212 to achieve radial centering and limiting of the first shaft 1 and the second shaft 2.

[0035] For example, Figure 1 As shown, the inner hole 21 can be a blind hole, and in some other embodiments, it can also be a through hole. The inner hole 21 can be provided at the left end of the second shaft 2. According to different usage modes, different parts of the inner hole 21 can be divided into a first hole section 211 and a second hole section 212, wherein the first hole section 211 can have only one, and the inner peripheral wall of the first hole section 211 can be integrally formed with a plurality of internal splines, and the plurality of internal splines can be arranged at intervals along the circumference of the inner hole 21. The inner peripheral wall of the second hole section 212 can be a smooth hole wall, and the number of the second hole sections 212 is the same as the number of the second shaft sections 12 mentioned above.

[0036] During assembly, the first axis 1 and the second axis 2 can be directly plugged and assembled. After the assembly is completed, Figure 2As shown, at this time, the external spline on the outer peripheral side of the first shaft segment 11 can be loosely matched with the internal spline on the inner peripheral wall of the first hole segment 211, and the stop of the internal spline and the external spline can realize the transmission requirement of synchronous rotation of the first shaft 1 and the second shaft 2 in the circumferential direction.

[0037] The second shaft segment 12 can be interference fit in the second hole segment 212. The limiting constraints of the first shaft segment 11 and the second hole segment 212 can achieve the effect of radial centering and limiting the first shaft 1 and the second shaft 2, thereby ensuring the centrality and coaxiality of the first shaft 1 and the second shaft 2 during transmission, thereby improving the high-speed unstable force caused by the spline transmitting torque, avoiding high-speed shaft system instability and vibration, and is also beneficial to improving the speed range of the motor, meeting the use needs of the high-speed trend of the motor.

[0038] In some other embodiments, the second shaft segment 12 may be provided in plurality, and in this case, the second hole segment 212 may also be provided in plurality. During assembly, the plurality of second shaft segments 12 are respectively interference-fitted in the plurality of second hole segments 212. Specifically, the second shaft segment 12 may be provided in two, three, etc., and in this case, the second hole segment 212 may also be provided in two, three, etc.

[0039] In some embodiments, at least part of the second shaft segment 12 is closer to the free end of the first shaft than the first shaft segment 11. Specifically, there is one second shaft segment 12, and the second shaft segment 12 is located at the free end of the first shaft 1. In some other embodiments, such as Figure 1 As shown, the free end may be the right end of the first shaft 1, and a portion of the second shaft segment 12 may be adjacent to the right end of the first shaft 1. In this case, the first shaft segment 11 is located on the left side of the portion of the second shaft segment 12. Thus, the end of the first shaft 1 may be limited, thereby avoiding a large deflection variation of the first shaft 1 during use.

[0040] In some embodiments, the first shaft segment 11 is disposed between two second shaft segments 12. Figure 1 and Figure 2 As shown, only two second shaft segments 12 may be provided, and the first shaft segment 11 may be integrally formed between the two second shaft segments 12, thereby forming positioning constraints on both the left and right ends of the first shaft segment 11, thereby further avoiding the situation of high-speed unstable force.

[0041] In some other embodiments, the first shaft segment 11 may also be disposed at the rightmost end of the first shaft 1 . In this case, the plurality of second shaft segments 12 may all be located on the left side of the first shaft segment 11 .

[0042] In some embodiments, there are two second shaft segments 12 , one of which is a large diameter segment 121 with a larger radial dimension, and the other is a small diameter segment 122 with a smaller radial dimension. The first shaft segment 11 is disposed between the large diameter segment 121 and the small diameter segment 122 .

[0043] For example, Figure 1 As shown, each second shaft segment 12 can be a circular shaft, wherein the large diameter segment 121 can be connected to the left side of the first shaft segment 11, and the small diameter segment 122 can be connected to the right side of the first shaft segment 11. Thus, the portion with a smaller radial dimension can be located at the outermost side, which is conducive to improving the convenience of assembly.

[0044] It should be noted that if Figure 1 and Figure 2 As shown, to match the above-mentioned large diameter section 121 and small diameter section 122, two second hole sections 212 may also be provided in the inner hole 21, and the apertures of the two second hole sections 212 are different, one of which is a large hole section 2121 with a larger aperture, and the other is a small hole section 2122 with a smaller aperture. The large hole section 2121 can be located on the left side of the first hole section 211, and the small hole section 2122 can be located on the right side of the first hole section 211.

[0045] When the first shaft 1 and the second shaft are assembled, the large diameter section 121 can be interference fit in the large hole section 2121 , and the small diameter section 122 can be interference fit in the small hole section 2122 .

[0046] In some embodiments, Figure 1 and Figure 2 As shown, the first shaft section 11, the large diameter section 121 and the small diameter section 122 can all be cylindrical, the radial dimension of the first shaft section 11 is smaller than the radial dimension of the large diameter section 121, and the radial dimension of the first shaft section 11 is larger than the radial dimension of the small diameter section 122. Thus, the right end of the first shaft 1 can be made into a stepped shaft shape as a whole, thereby fully meeting the installation requirements of the assembly.

[0047] In some embodiments, in the axial direction along the first shaft 1, the length dimension of the first shaft segment 11 is greater than the length dimension of any one of the large diameter segment 121 and the small diameter segment 122. Figure 2 As shown, the axial direction of the first shaft 1 can be left-right direction, and the length dimension of the first shaft segment 11 can be Figure 2 The length of the large diameter section 121 can be Figure 2 The length of the small diameter section 122 can be Figure 2 Size C in the middle.

[0048] Among them, dimension B is larger than dimension A, and dimension B is also larger than dimension C. Therefore, when assembling the first shaft 1 and the second shaft 2, due to the longer dimension B, the first shaft section 11 and the first hole section 211 can be firstly assembled by spline guide, while the interference fit between the large diameter section 121 and the large hole section 2121, and the interference fit between the small diameter section 122 and the small hole section 2122 are all delayed after the assembly of the first shaft section 11 and the first hole section 211, which further improves the convenience of assembly.

[0049] In some embodiments, the length of any one of the large diameter section 121 and the small diameter section 122 does not exceed one third of the length of the first shaft section 11. Specifically, the dimension A is less than or equal to one third of the dimension B, and the dimension C is less than or equal to one third of the dimension B. Thus, installation convenience is fully guaranteed.

[0050] In some embodiments, the length of the large diameter section 121 is consistent with the length of the small diameter section 122. That is, the above-mentioned dimension A is the same as the above-mentioned dimension C, so that the interference fit between the large diameter section 121 and the large hole section 2121 and the interference fit between the small diameter section 122 and the small hole section 2122 can be performed and completed at the same time.

[0051] In some embodiments, the cross section of the first shaft segment 11 and the cross section of the second shaft segment 12 are both circular surfaces. That is, the first shaft segment 11 and each second shaft segment 12 can be cylindrical. In some other embodiments, the first shaft segment 11 and the second shaft segment 12 can also be other shapes such as square shafts.

[0052] In some embodiments, in the axial direction of the first shaft 1, the radial dimension of the first shaft segment 11 increases first and then decreases. For example, in the left-right direction, the first shaft segment 11 may be drum-shaped as a whole, that is, the radial dimension of the middle portion of the first shaft segment 11 is larger, thereby satisfying the use requirements of interference fitting and further improving the convenience of assembly.

[0053] In some other embodiments, the first shaft segment 11 may also be a straight axis, that is, the radial dimension of the first shaft segment 11 remains unchanged.

[0054] In some embodiments, the first shaft 1 is provided with an annular end surface 13 , and the annular end surface 13 is used to abut against the end surface of the second shaft 2 on the peripheral side of the inner hole 21 to achieve axial limitation between the first shaft 1 and the second shaft 2 .

[0055] For example, Figure 1 As shown, the annular end face 13 can be located at the right end of the first shaft 1 and can surround the outer peripheral side of the large diameter section 121. When the first shaft 1 and the second shaft 2 are assembled, the annular end face 13 can stop contact with the left end face of the second shaft 2, thereby achieving the limitation of the first shaft 1 and the second shaft 2 in the left and right directions.

[0056] In some embodiments, Figure 3 As shown, the electric drive system includes a motor 3 and a reducer 4 , the motor 3 includes a motor shaft, the motor shaft forms the above-mentioned first shaft 1 , and the reducer 4 includes an input shaft, the input shaft forms the above-mentioned second shaft 2 .

[0057] In some embodiments, the motor 3 includes a motor housing 31, a first bearing 32 and an elastic member 33. The motor 3 can be arranged on the left side of the reducer 4, and the right end of the motor housing 31 can be provided with an opening, and the motor shaft can extend from the opening and be plugged and assembled with the input shaft of the reducer 4.

[0058] The motor shaft is provided with a first shoulder, and the first bearing 32 is assembled at the first shoulder and is located between the motor housing 31 and the motor shaft. Specifically, the inner ring of the first bearing 32 can be sleeved on the outer peripheral side of the motor shaft, and the outer ring of the first bearing 32 can be fitted in the motor housing 31, so that the motor housing 31 can play a role in supporting and providing an installation point.

[0059] The elastic member 33 is disposed between the motor housing 31 and the first bearing 32, and is used to press the first bearing 32 against the first shaft shoulder. For example, the elastic member 33 may be a wave spring, and the elastic member 33 may be sleeved on the outer peripheral side of the motor shaft, and in the left-right direction, the elastic member 33 may be sandwiched between the motor housing 31 and the first bearing 32.

[0060] When in use, the elastic member 33 can apply an elastic force to the first bearing 32, thereby providing a preload force for the first bearing 32 on the one hand, and providing an axial fit force for the motor shaft and the input shaft on the other hand, thereby ensuring axial stability.

[0061] In some embodiments, the reducer 4 includes a reducer housing, a second bearing 43, a third bearing 44 and a washer 45. The second bearing 43 and the third bearing 44 are both located in the reducer housing, the input shaft is provided with a second shoulder and a third shoulder, the second bearing 43 is assembled at the second shoulder and is located between the reducer housing and the input shaft, the third bearing 44 is assembled at the third shoulder and is located between the reducer housing and the input shaft, and the second bearing 43 is located between the first bearing 32 and the third bearing 44.

[0062] For example, Figure 4 As shown, the reducer housing may include a first end cover 41 and a second end cover 42 arranged opposite to each other in the left-right direction, and the first end cover 41 and the second end cover 42 may both be in an annular shape and sleeved on the outer circumference of the input shaft. The inner ring of the second bearing 43 may be sleeved on the outer circumference of the input shaft, and the outer ring of the second bearing 43 may fit in the first end cover 41. The inner ring of the third bearing 44 may be sleeved on the outer circumference of the input shaft, and the outer ring of the third bearing 44 may fit in the second end cover 42.

[0063] In the left-right direction, the inner ring of the second bearing 43 can be stopped and limited by the second shaft shoulder, and the outer ring of the second bearing 43 can be stopped and limited by the first end cover 41. The inner ring of the third bearing 44 can be stopped and limited by the third shaft shoulder, and the outer ring of the third bearing 44 can be stopped and limited by the second end cover 42.

[0064] The washer 45 surrounds the outer peripheral side of the input shaft and is sandwiched between the third bearing 44 and the reducer housing. Figure 3 As shown, the washer 45 may be a gasket, etc. The washer 45 may be sleeved on the outer peripheral side of the input shaft, and the washer 45 may be clamped between the outer ring of the third bearing 44 and the second end cover 42, so as to ensure the axial preload of the input shaft.

[0065] In some embodiments, the electric drive system further includes a rotor core 5 , which is mounted on the outer circumference of the motor shaft so as to provide torque for the rotation of the motor shaft.

[0066] The following describes a vehicle according to an embodiment of the present disclosure.

[0067] The vehicle of the embodiment of the present disclosure includes the electric drive system as in any of the above embodiments. The vehicle may be a car, SUV, bus or other vehicle. Figure 4 As shown, the vehicle may further include a motor controller, etc. When in use, the motor controller may control the motor to rotate, and the motor shaft may transmit the rotational effect to the reducer 4, and then to the wheel end, thereby realizing the rotational drive of the wheel at the wheel end.

[0068] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present disclosure. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present disclosure.

Claims

1. An electric drive system, characterized in that: include: a first shaft, the first shaft comprising a first shaft segment and a second shaft segment; The second shaft is provided with an inner hole, the inner hole comprises a first hole section and a second hole section, the first shaft section is key-fitted in the first hole section, and the second shaft section is interference-fitted in the second hole section.

2. The electric drive system according to claim 1, characterized in that: At least a portion of the second shaft segment is closer to the free end of the first shaft than the first shaft segment.

3. The electric drive system according to claim 2, characterized in that: There are two second shaft segments, one of which is a large-diameter segment with a larger radial dimension, and the other is a small-diameter segment with a smaller radial dimension, and the first shaft segment is arranged between the large-diameter segment and the small-diameter segment.

4. The electric drive system according to claim 3, characterized in that: The radial dimension of the first shaft segment is smaller than the radial dimension of the large diameter segment, and the radial dimension of the first shaft segment is larger than the radial dimension of the small diameter segment.

5. The electric drive system according to claim 4, characterized in that: In the axial direction along the first shaft, the length dimension of the first shaft segment is greater than the length dimension of any one of the large-diameter segment and the small-diameter segment.

6. The electric drive system according to claim 5, characterized in that: The length dimension of any one of the large diameter segment and the small diameter segment does not exceed one third of the length dimension of the first shaft segment; And / or, the length dimension of the large diameter segment is consistent with the length dimension of the small diameter segment.

7. The electric drive system according to claim 1, characterized in that: The cross-sections of the first shaft segment and the second shaft segment are both circular surfaces.

8. The electric drive system according to claim 1, characterized in that: The first shaft is provided with an annular end surface, and the annular end surface is used to abut against the end surface of the second shaft on the circumferential side of the inner hole to achieve axial limitation between the first shaft and the second shaft.

9. The electric drive system according to any one of claims 1 to 8, characterized in that: The invention comprises a motor and a reducer, wherein the motor comprises a motor shaft, and the motor shaft forms the first shaft; and the reducer comprises an input shaft, and the input shaft forms the second shaft.

10. A vehicle, characterized in that: The invention comprises an electric drive system as claimed in any one of claims 1 to 9.

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