CN211720418U - Motor shaft and coaxial centering structure of reduction gear axle in electric drive assembly - Google Patents

Abstract

The utility model relates to a motor shaft and the coaxial centering structure of reduction gear axle in electric drive assembly, include: the motor is provided with a motor shaft; the reducer is provided with a reducer shaft, the motor shaft is in coaxial transmission connection with the reducer shaft, and a coaxial centering smooth surface is arranged at the connecting end between the motor shaft and the reducer shaft for radial centering so as to ensure that the motor shaft and the reducer shaft are coaxial and concentric. The utility model discloses can reduce among the electric drive assembly the machining precision requirement of drive disk assembly, reduce the drive disk assembly wearing and tearing, improve the life of electric drive assembly, improve NVH's effect.

Description

Motor shaft and coaxial centering structure of reduction gear axle in electric drive assembly

Technical Field

The utility model belongs to the electric automobile field, concretely relates to motor shaft and the coaxial centering structure of reduction gear axle in electric drive assembly.

Background

With the promotion of national energy-saving and emission-reducing policies, new energy automobiles are greatly developed, the new energy automobiles adopt an electric drive assembly, a driving motor is connected with a speed reducer and then drives the automobiles to run, the connection between the motor and the speed reducer generally adopts a spline connection mode, and the spline connection has the characteristics of good guidance, good centering performance, large transmission torque, capability of bearing larger load and the like. However, the fitting accuracy of the radial centering surface of the spline greatly affects the working performance and service life of the spline, the radial fitting clearance is too small, the assembly performance and the sliding type of the spline pair are affected, the clearance is too large, the movement accuracy of two-shaft fitting is affected, the meshing depth is affected, noise is increased, abrasion is accelerated, and when the radial clearance exceeds a certain limit, an offset gear phenomenon can occur.

Through patent retrieval, with the utility model discloses there is following patent mainly to have the patent of certain relation:

1. the invention relates to an electric automobile and an integrated power assembly thereof, and discloses Chinese invention patents with the application number of 201811071754.0, the application date of 2018.09.14, the publication number of CN 108944394A, the publication date of 2018.12.07, the name of the electric automobile and the integrated power assembly thereof, and the application name of the inventor of the Ougeli transmission company Limited on the West. In addition, one end of the output shaft of the motor extends into the cavity of the speed reducer and is connected with the input shaft of the speed reducer through a spline. In one aspect, the second input bearing can support the reducer input shaft while also providing support for the motor output shaft, since the second input bearing is proximate to the motor output shaft. On the other hand, the motor output shaft and the reducer input shaft transmit torque through spline connection, and the spline connection has a strong radial limiting effect, so that the motor output shaft and the reducer input shaft can be mutually supported. Therefore, the reliability in the transmission process is not affected. Therefore, the electric automobile and the integrated power assembly thereof have the advantages of reducing cost and simultaneously considering higher reliability.

2. The invention relates to an electric automobile and an integrated power assembly thereof, and the invention relates to Chinese invention patents with the application number of ' 201811071481.X ', the application date of ' 2018.09.14 ', the publication number of ' CN 108973631A ', the publication date of ' 2018.12.11 ', the name of ' the electric automobile and the integrated power assembly thereof ', and the application name of ' Ougueri drive Co., Ltd, of Tanzhou. In addition, one end of the input shaft of the speed reducer extends into the cavity of the motor and is connected with the output shaft of the motor through a spline. On the one hand, because the second output bearing is close to the input shaft of the speed reducer, the second output bearing can support the output shaft of the motor and simultaneously provide support for the input shaft of the speed reducer. On the other hand, the motor output shaft and the reducer input shaft transmit torque through spline connection, and the spline connection has a strong radial limiting effect, so that the motor output shaft and the reducer input shaft can be mutually supported. Therefore, the reliability in the transmission process is not affected. Therefore, the electric automobile and the integrated power assembly thereof have the advantages of reducing cost and simultaneously considering higher reliability.

3. The utility model relates to an electric automobile and integrated power assembly thereof, be formed with in the casing and lead the oil passageway, and lead the opening of oil passageway one end and be located the inner wall of interface channel, the opening of the other end is located the outer wall of casing, the utility model discloses an application number is "201822021222.8", application date is "2018.12.04", the publication number is "CN 209309277U", the publication date is "2019.08.27", the name is "electric automobile and integrated power assembly thereof", the applicant is the utility model patent of "Ouguii transmission limited company of Ozhou province", this utility model relates to an electric automobile and integrated power assembly thereof, be formed with in the casing and lead the. In case the shaft seal structure is invalid, and when the lubricating oil in the reduction gear cavity permeates to the motor cavity, the lubricating oil leaked to one side of the motor cavity flows into the oil guide channel, and the opening, located on the outer wall of the shell, of the oil guide channel is detected. Therefore, whether the shaft sealing structure fails or not can be accurately judged without unpacking operation, and the failed shaft sealing structure can be conveniently and timely replaced. Above-mentioned integrated power assembly leads the oil passageway through setting up, has avoided causing the condition emergence of damage to drive assembly because of the axle seal structure change untimely often to the potential safety hazard has been reduced effectively.

4. The invention relates to a power assembly of an electric vehicle and an electric vehicle with the power assembly, wherein the power assembly is disclosed as ' 201810145470.5 ', 2018.02.12 ' on the application date, CN 110154749A ' on the publication date, 2019.08.23 ' on the publication date, and ' the power assembly of the electric vehicle and the electric vehicle with the power assembly, and the applicant is Chinese invention patent of Biedi Limited company ', and the invention relates to and discloses the power assembly of the electric vehicle and the electric vehicle with the power assembly, and the power assembly comprises: the box assembly, have the open-ended motor box and follow the gearbox box that the direction that the motor box center was kept away from to the opening orientation set up including box assembly one side, the internal motor that is equipped with of motor box, the motor has the motor shaft, the one end of motor shaft is passed the opening and is stretched into in the gearbox box, and the one end of motor shaft has the external splines, the one side at the opening place of motor box is established to the gearbox box, the accommodation space that is used for holding the variable speed portion is injectd to the gearbox box, the variable speed portion has the main shaft, the main shaft has the through-hole that the axial of following the main shaft link up, be equipped with the internal splines on the internal perisporium of through-hole, the one end. The power assembly of the electric vehicle has good processing technology, NVH performance and durability.

5. The utility model discloses a utility model patent of "power assembly and electric vehicle of electric vehicle", utility model patent that application number is "201820254886.6", application date is "2018.02.12", publication number is "CN 208021193U", publication date is "2018.10.30", the name is "electric vehicle's power assembly and electric vehicle that has it", the applicant is "biyadi limited company", this utility model discloses an electric vehicle's power assembly, electric vehicle's power assembly includes: the gearbox comprises a box body, a first bearing and a second bearing, wherein the box body comprises a motor box body with an opening on one side and a gearbox box body extending out from the opening in a direction far away from the center of the motor box body; the gearbox box, the gearbox box is established in the one side at the opening place of motor box, and the accommodation space that is used for holding the derailleur is injectd jointly to gearbox box and gearbox box, the one end of the main shaft of derailleur and the one end fixed connection of motor shaft are equipped with the second bearing between the other end of main shaft and the gearbox box, are equipped with the third bearing between at least one in main shaft and the motor shaft and the box. According to the utility model discloses an electric vehicle's power assembly, the support effect is good.

6. The utility model discloses a utility model patent of "power assembly and electric vehicle that has it" that application number is "201820254698.3", application date is "2018.02.12", publication number is "CN 208180748U", publication date is "2018.12.04", the name is "electric vehicle's power assembly and electric vehicle that has it", the applicant is "biaddi limited", this utility model discloses an electric vehicle's power assembly and electric vehicle that has it, electric vehicle's power assembly includes: the box body comprises a motor box body and a transmission case, a motor is arranged in the motor box body and provided with a motor shaft, one end of the motor shaft penetrates through the opening and extends into the transmission case, and the motor box body and the transmission case are integrally formed; the gearbox box, the gearbox box is established in one side at the opening place of motor box, the accommodation space that is used for holding the gear shift portion is injectd jointly to gearbox box and gearbox shell, the gear shift portion has the main shaft, the main shaft has the through-hole that link up along the axial of main shaft, the one end cooperation of motor shaft in the through-hole and with main shaft fixed connection, be equipped with the oil blanket between the one end at the adjacent motor box center of main shaft and the inner wall of box, be equipped with the sealing washer between the one end of motor shaft and the inner wall of through-. According to the utility model discloses electric vehicle's power assembly can guarantee the normal operating of motor well.

Electric automobile electric drive assembly motor shaft and reduction gear shaft all are through inside and outside splined connection in the above-mentioned patent, because inside and outside spline fit precision is not high, lead to having the clearance between the inside and outside spline, at the in-process of transmission torque, can make motor shaft and reduction gear shaft disalignment and the eccentricity appear, and the eccentricity still can be along with rotating and constantly changing moreover. If the bearing at the connecting part of the motor shaft and the reducer shaft is arranged on the reducer shaft, the motor shaft and the reducer shaft are not coaxial, so that the connecting end of the motor shaft and the reducer shaft can swing, a rotor and a stator of the motor are not coaxial, and the transmission efficiency of the electric drive assembly can be reduced; if the bearing at the connection position of the motor shaft and the reducer shaft is arranged on the motor shaft, the connection end of the reducer shaft and the motor shaft can swing, gear abrasion of the reducer can be accelerated, and the service life of the electric drive assembly can be shortened.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is that the defect to motor shaft and the not coaxial of reduction gear axle connection cooperation precision is not high, motor shaft and reduction gear axle that exists among the prior art provides: a coaxial centering structure of a motor shaft and a reducer shaft in an electric drive assembly.

In order to solve the technical problem, the utility model discloses the technical scheme who takes does: a motor shaft and speed reducer shaft coaxial centering structure of an electric drive assembly comprises: the motor is provided with a motor shaft; the speed reducer is provided with a speed reducer shaft, the motor shaft is in coaxial transmission connection with the speed reducer shaft through a transmission piece, a coaxial centering smooth surface is arranged at the connecting end between the motor shaft and the speed reducer shaft, and a lubricating oil groove is formed in the coaxial centering smooth surface (4). Lubricating oil is introduced to the coaxial centering smooth surface and the transmission part to lubricate and cool the coaxial centering smooth surface and the transmission part, so that the abrasion of the coaxial centering smooth surface and the transmission part is reduced, and the corrosion is prevented.

Further, the coaxial centering optical surface comprises: the optical axis and with the unthreaded hole that the optical axis cooperation was used for radial centering adopt clearance fit between optical axis and the unthreaded hole. The radial centering effect is good, and the processing and the installation are simple and convenient.

Further, the driving medium is the spline that sets up at motor shaft and reduction gear axle connection end, the spline includes: the motor shaft and the reducer shaft are in matched transmission connection with the internal spline through the external spline. The centering device has the advantages of good guidance, good centering performance, large transmission torque and capability of bearing larger load.

Further, the oil groove is a spiral groove, and comprises: an outer spiral groove and/or an inner spiral groove. The lubricating oil is screwed into the coaxial centering smooth surface and the spline by utilizing the chip removal effect of a drill bit generated when the motor rotates, and lubricating oil flow is formed to lubricate the coaxial centering smooth surface and the spline and take away friction heat, so that the abrasion of the coaxial centering smooth surface and the spline is reduced, and the coaxial centering smooth surface and the spline are prevented from being corroded.

Further, external splines and optical axis set up on the motor shaft, internal splines and unthreaded hole set up on the reduction gear axle. So as to utilize the central through hole on the speed reducer shaft, thereby being convenient for forming lubricating oil flow and enhancing the lubricating and cooling effects.

Further, the outer spiral groove is provided on an outer peripheral surface of an optical axis of the motor shaft, and a rotation direction of the outer spiral groove is opposite to a rotation direction of the motor shaft when the electric vehicle advances. The lubricating is screwed into the coaxial centering smooth surface and the deep part of the spline by utilizing the chip removal effect of a drill bit generated when the motor rotates.

Further, the inner spiral groove is arranged on the inner circumferential surface of the unthreaded hole of the speed reducer shaft, and the spiral direction of the inner spiral groove is opposite to the rotating direction of the motor shaft when the electric automobile moves forwards. The lubricating is screwed into the coaxial centering smooth surface and the deep part of the spline by utilizing the chip removal effect of a drill bit generated when the motor rotates.

Further, internal spline and unthreaded hole set up on the motor shaft, external spline and optical axis set up on the reduction gear axle.

Further, the inner spiral groove is arranged on the inner circumferential surface of the unthreaded hole of the motor shaft, and the spiral direction of the inner spiral groove is the same as the rotating direction of the motor shaft when the electric automobile moves forwards. The lubricating is screwed into the coaxial centering smooth surface and the deep part of the spline by utilizing the chip removal effect of a drill bit generated when the motor rotates.

Further, the outer spiral groove is provided on the outer peripheral surface of the optical axis of the reducer shaft, and the spiral direction of the outer spiral groove is the same as the rotation direction of the motor shaft when the electric vehicle advances. The lubricating is screwed into the coaxial centering smooth surface and the deep part of the spline by utilizing the chip removal effect of a drill bit generated when the motor rotates.

The utility model has the advantages that: the coaxial centering smooth surface is arranged at the coaxial connecting end of the motor shaft and the reducer shaft of the electric drive assembly, so that the machining precision requirement of a transmission part in the electric drive assembly can be reduced, the abrasion of the transmission part is reduced, the service life of the electric drive assembly is prolonged, and the NVH effect is improved. Meanwhile, the spiral groove is formed in the coaxial centering smooth surface, lubricating oil is screwed into the coaxial centering smooth surface and the spline by using the chip removal effect of a similar drill bit generated when the motor rotates, lubricating oil flow is formed to lubricate the coaxial centering smooth surface and the spline, friction heat is taken away, the abrasion of the coaxial centering smooth surface and the spline is reduced, and the coaxial centering smooth surface and the spline are prevented from being corroded.

Drawings

Figure 1 is a schematic diagram of the structure of an electric drive assembly,

FIG. 2 is an enlarged view of part A of FIG. 1,

figure 3 is a schematic view of a motor shaft according to the first embodiment,

figure 4 is a schematic view of a reducer shaft according to a first embodiment,

FIG. 5 is a schematic view of the motor shaft of the first embodiment before being connected to the reducer,

FIG. 6 is a schematic view showing the motor shaft of the first embodiment after being connected to a reducer,

figure 7 is a schematic view of a motor shaft of the second embodiment,

figure 8 is a schematic view of a reducer shaft according to a second embodiment,

FIG. 9 is a schematic view of the motor shaft of the second embodiment before being connected to the reducer,

FIG. 10 is a schematic view showing the motor shaft of the second embodiment after being connected to a reducer,

in the figure: 1-shell, 2-motor, 21-motor shaft, 3-reducer, 31-reducer shaft, 4-coaxial centering smooth surface, 41-optical axis, 42-unthreaded hole, 5-spiral groove, 51-external spiral groove, 52-internal spiral groove, 6-spline, 51-external spline, 52-internal spline, n-rotation direction of motor shaft when automobile moves forward, L-lubricating oil flow direction.

Detailed Description

The invention will be further described by means of specific embodiments and with reference to the accompanying drawings:

as shown in fig. 1 and 2: a motor shaft and speed reducer shaft coaxial centering structure of an electric drive assembly comprises: casing 1, motor 2 and reduction gear 3, shown casing 1 divide into motor chamber and reduction gear chamber, and the motor setting is in the motor intracavity, and the reduction gear setting is in the reduction gear intracavity.

The motor 2 is provided with a motor shaft 21; the speed reducer 3 is provided with a speed reducer shaft 31, and the motor shaft 21 penetrates through the motor cavity and is in coaxial transmission connection with the speed reducer shaft 31. Flat keys, toothed discs, friction discs, etc. may be used, but the most common is a splined connection 6. The spline 6 is formed by combining an external spline 61 and an internal spline 62, and torque is transmitted by meshing the external spline 61 with the internal spline 62.

When the motor shaft 21 and the reducer shaft 31 are coaxially connected, they are usually rotatably connected to the housing 1 by three bearings, one side bearing is disposed at the end of the motor shaft 21 away from the reducer, one side bearing is disposed at the end of the reducer shaft 31 away from the motor, and an intermediate bearing is disposed at the connecting end of the motor shaft 21 and the reducer shaft 31. The intermediate bearing can be arranged on the motor shaft 21 or on the reducer shaft 31; the motor cavity can be arranged in the motor cavity, and the speed reducer cavity can also be arranged in the speed reducer cavity.

Since the radial fitting accuracy of the spline 6 greatly affects the working performance and the life of the spline 6, if the radial fitting clearance is too small, the assembling property and the slidable type of the spline 6 are affected; if the clearance is too large, the motion precision of the matching of the two shafts is influenced, the meshing depth is influenced, the noise is increased, and the abrasion is accelerated. When the radial clearance exceeds a certain limit, an offset gear phenomenon also occurs. If the spline 6 is adopted for centering, the spline 6 is high in machining precision requirement, difficult to machine, complex in process and high in manufacturing cost, and the problems of difficulty in assembly and poor NVH effect exist.

The utility model discloses set up coaxial centering part at motor shaft 21 and reduction gear shaft 31's link to guarantee motor shaft 21 and reduction gear shaft 31 radial centering, with reduce to spline 6's machining precision requirement, reduce spline 6's wearing and tearing, improve the life of electric drive assembly, improve NVH's effect.

The coaxial centering component can adopt radial centering of a chuck or radial centering of matching of a taper hole and a taper surface, and in the embodiment, the coaxial centering smooth surface 4 is adopted to ensure radial centering of the motor shaft 21 and the reducer shaft 31. The coaxial centering light surface 4 comprises: the optical axis 41 is inserted into the light hole 42, and the optical axis 41 and the light hole 42 are in clearance fit. The clearance fit between the optical axis 41 and the light hole 42 is not lower than H7/F6, preferably H6/g 5. The surface roughness of the optical axis 41 and the surface roughness of the unthreaded hole 42 are preferably 0.8, the cylindricity tolerance grade is seven, and the axiality relative to the outer diameter of the shaft end of the mounting bearing is 6-7.

The radial centering mode not only ensures the coaxial and concentric requirements of the motor shaft 21 and the reducer shaft 31, but also is convenient for processing and installation.

One embodiment is shown in fig. 3 to 6: when the external spline 61 is disposed at the tip of the connecting end of the motor shaft 21, the optical axis 41 is disposed in the immediate vicinity of the external spline 61; the unthreaded hole 42 is provided at the tip of the connecting end of the reducer shaft 31, and the internal spline 62 is provided in the immediate vicinity of the unthreaded hole 42. The connecting end of the motor shaft 21 is inserted into the connecting end of the reducer shaft 31, so that the external spline 61 is engaged with the internal spline 62 for transmitting torque; while the optical axis 41 cooperates with the aperture 42 to ensure coaxial centering of the motor shaft 21 and the reducer shaft 31.

In order to prevent wear and corrosion of the coaxial centering facets 4 and splines 6, it is necessary to lubricate the coaxial centering facets 4 and splines 6. Due to the high-precision clearance fit between the optical axis 41 and the unthreaded hole 42 in the coaxial centering smooth surface 4, lubricating oil is difficult to enter the coaxial centering smooth surface 4 and reach the spline 6 to lubricate the spline 6. Therefore, oil grooves are provided on the outer circumferential surface of the optical axis 41 and/or the inner circumferential surface of the unthreaded hole 42 to guide the lubricating oil to the centering smooth surface 4 and the spline 6 for lubrication and to remove frictional heat.

The oil grooves may be axial grooves on the matching surface of the optical axis 41 and the optical hole 42 of the motor shaft 21, circumferential grooves, grooves interwoven with the circumferential direction in the axial direction, and preferably spiral grooves 5 on the matching surface of the optical axis 41 and the optical hole 42. The section of the spiral groove 5 is V-shaped, U-shaped or circular arc-shaped.

The helical groove 5 includes: an outer spiral groove 51 provided on the surface of the optical axis 41 and an inner spiral groove 52 provided on the inner surface of the unthreaded hole 42. The outer spiral groove 51 may be provided only on the optical axis 41, or the inner spiral groove 52 may be provided only on the unthreaded hole 42; the outer spiral groove 51 may be provided on the optical axis 41, and the inner spiral groove 52 may be provided on the unthreaded hole 42.

The purpose of the helical groove 5 is: by means of the function of chip removal of the drill bit generated when the motor 2 rotates, the lubrication is screwed into the coaxial centering smooth surface 4 and the spline 6, and continuous lubricating oil flow can be formed.

Since the rotation directions of the motor are opposite to each other when the vehicle moves forward and backward, and the forward movement time of the vehicle is most important in the use of the vehicle, the rotation directions of the outer spiral groove 51 and the inner spiral groove 52 should be determined according to the rotation direction n of the motor when the vehicle moves forward.

As shown in fig. 3: the male spiral groove 51 provided on the outer peripheral surface of the optical axis 41 of the motor shaft 21 is rotated in the direction opposite to the rotating direction n of the motor shaft 21 when the electric vehicle moves forward.

As shown in fig. 4: the inner spiral groove 52 provided on the inner circumferential surface of the unthreaded hole 42 in the reduction gear shaft 31 is rotated in the direction opposite to the rotation direction n of the motor shaft 21 when the electric vehicle advances.

Fig. 5 is a schematic diagram before the motor shaft is connected with the reducer.

As shown in fig. 6, which is a schematic view after the motor shaft and the reducer are connected, when the motor shaft 21 and the reducer shaft 31 rotate in the rotation direction n of the motor shaft 21 when the electric vehicle advances, the lubricating oil enters the outer spiral groove 51 and/or the inner spiral groove 52 from the gap between the motor shaft 21 and the reducer shaft 31, and is supplied to the spline 6 by the chip removal effect similar to that of a drill generated when the motor shaft 21 rotates, and is finally discharged through the central through hole of the reducer shaft 31 after the spline 6 is lubricated and cooled. During the rotation of the motor shaft 21, the lubricating oil continuously passes through the above-described path to form a flow of lubricating oil, the flow direction of which is shown as L in fig. 6.

Example two is shown in figures 7 and 10: when the external spline 61 is disposed at the tip of the connecting end of the reducer shaft 31, the optical axis 41 is disposed in the immediate vicinity of the external spline 61; the unthreaded hole 42 is provided at the tip of the connection end of the motor shaft 21, and the internal spline 62 is provided in the immediate vicinity of the unthreaded hole 42. The connection end of the reducer shaft 31 is inserted into the connection end of the motor shaft 21, so that the external spline 61 is engaged with the internal spline 62 for transmitting torque; while the optical axis 41 cooperates with the aperture 42 to ensure coaxial centering of the motor shaft 21 and the reducer shaft 31.

As shown in fig. 7: the inner spiral groove 52 provided on the inner circumferential surface of the unthreaded hole 42 in the motor shaft 21 is rotated in the same direction as the rotation direction n of the motor shaft 21 when the electric vehicle advances.

As shown in fig. 8: the male spiral groove 51 formed on the outer peripheral surface of the optical axis 41 of the reducer shaft 31 is rotated in the same direction as the rotation direction n of the motor shaft 21 when the electric vehicle moves forward.

Fig. 9 is a schematic diagram before the motor shaft is connected with the reducer.

As shown in fig. 10, which is a schematic view after the motor shaft and the reducer are connected, when the motor shaft 21 and the reducer shaft 31 rotate in the rotating direction n of the motor shaft 21 when the electric vehicle advances, the lubricating oil enters the outer spiral groove 51 and/or the inner spiral groove 52 from the gap between the motor shaft 21 and the reducer shaft 31, and is delivered to the spline 6 by the chip removal effect similar to that of a drill generated when the motor shaft 21 rotates, and after lubricating and cooling the spline 6, the lubricating oil turns in the blind hole of the motor shaft 21 and is finally discharged through the central through hole of the reducer shaft 31. During the rotation of the motor shaft 21, the lubricating oil continuously passes through the above-described path to form a flow of lubricating oil, the flow direction of which is shown by L in fig. 10.

In summary, the following steps: the utility model has the advantages that: the coaxial centering smooth surface is arranged at the coaxial connecting end of the motor shaft and the reducer shaft of the electric drive assembly, so that the machining precision requirement of a transmission part in the electric drive assembly can be reduced, the abrasion of the transmission part is reduced, the service life of the electric drive assembly is prolonged, and the NVH effect is improved. Meanwhile, the spiral groove is formed in the coaxial centering smooth surface, lubricating oil is screwed into the coaxial centering smooth surface and the spline by using the chip removal effect of a similar drill bit generated when the motor rotates, lubricating oil flow is formed to lubricate the coaxial centering smooth surface and the spline, friction heat is taken away, the abrasion of the coaxial centering smooth surface and the spline is reduced, and the coaxial centering smooth surface and the spline are prevented from being corroded.

The above embodiments are provided only for the purpose of illustration, not for the limitation of the present invention, and those skilled in the relevant art can make various changes or modifications without departing from the spirit and scope of the present invention, so all equivalent technical solutions should also belong to the protection scope of the present invention, and the protection scope of the present invention should be defined by the claims.

Claims (10)

1. A motor shaft and reducer shaft coaxial centering structure in an electric drive assembly, comprising: the motor comprises a shell (1), a motor (2) and a speed reducer (3), wherein the motor (2) is provided with a motor shaft (21); reduction gear (3) set up and are equipped with reduction gear axle (31), motor shaft (21) are connected its characterized in that through the coaxial transmission of driving medium with reduction gear axle (31): the connecting end between the motor shaft (21) and the reducer shaft (31) is provided with a coaxial centering part so as to realize that the motor shaft (21) and the reducer shaft (31) are coaxial and concentric.

2. The coaxial centering structure of claim 1, wherein: the coaxial centering component is a coaxial centering smooth surface (4), and the coaxial centering smooth surface (4) comprises: the optical axis (41) and the light hole (42) matched with the optical axis (41) for radial centering are in clearance fit between the optical axis (41) and the light hole (42).

3. The coaxial centering structure of claim 2, wherein: the driving medium is spline (6) that sets up at motor shaft (21) and reduction gear axle (31) link, spline (6) include: the motor shaft (21) and the speed reducer shaft (31) are in matched transmission connection with the inner spline (62) through the outer spline (61).

4. The coaxial centering structure of claim 3, wherein: be provided with the oil groove on coaxial centering plain noodles (4), the oil groove is helicla flute (5), includes: an outer spiral groove (51) and/or an inner spiral groove (52).

5. The coaxial centering structure of claim 4, wherein: the external spline (61) and the optical axis (41) are arranged on the motor shaft (21), and the internal spline (62) and the unthreaded hole (42) are arranged on the reducer shaft (31).

6. The coaxial centering structure of claim 5, wherein: the outer spiral groove (51) is provided on the outer peripheral surface of the optical axis (41) of the motor shaft (21), and the direction of rotation of the outer spiral groove (51) is opposite to the direction of rotation (n) of the motor shaft (21) when the electric vehicle is moving forward.

7. The coaxial centering structure of claim 5, wherein: the inner spiral groove (52) is arranged on the inner circumferential surface of the unthreaded hole (42) of the speed reducer shaft (31), and the spiral direction of the inner spiral groove (52) is opposite to the rotating direction (n) of the motor shaft (21) when the electric automobile moves forwards.

8. The coaxial centering structure of claim 4, wherein: the inner spline (62) and the unthreaded hole (42) are arranged on the motor shaft (21), and the outer spline (61) and the optical axis (41) are arranged on the reducer shaft (31).

9. The coaxial centering structure of claim 8, wherein: the inner spiral groove (52) is arranged on the inner circumferential surface of the unthreaded hole (42) of the motor shaft (21), and the spiral direction of the inner spiral groove (52) is the same as the rotating direction (n) of the motor shaft (21) when the electric automobile moves forwards.

10. The coaxial centering structure of claim 8, wherein: the outer spiral groove (51) is provided on the outer peripheral surface of the optical axis (41) of the reducer shaft (31), and the direction of rotation of the outer spiral groove (51) is the same as the direction of rotation (n) of the motor shaft (21) when the electric vehicle is moving forward.

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