CN220067111U - Balance disc for motor, rotor assembly, motor and vehicle - Google Patents

Abstract

The present disclosure relates to a balance disc for a motor, a rotor assembly, a motor and a vehicle. The balance disc is provided with a first oil drain groove which is arranged on a first end face of the balance disc, which is used for facing the rotor core, and is used for communicating with at least one first through hole in a plurality of first through holes on the end face of the rotor core; the balance disc is further provided with a first oil drain hole, the first oil drain hole is communicated with the first end face and the second end face on the balance disc, the first oil drain hole is used for being communicated with a first through hole which is not communicated with the first oil drain groove in a plurality of first through holes, and the first through hole extends along the axial direction of the rotor core and is communicated with two end faces of the rotor core. The first oil drain hole may be configured as a cooling oil release passage communicating with the first through hole, through which cooling oil entering the first through hole not communicating with the first oil drain groove may be discharged, the problem of oil accumulation of the first through hole not used for oil running may be effectively solved, and NVH performance of the motor may be improved.

Description

Balance disc for motor, rotor assembly, motor and vehicle

Technical Field

The present disclosure relates to the field of motor technologies, and in particular, to a balance disc for a motor, a rotor assembly, a motor, and a vehicle.

Background

In the related art, for oil cooling of a motor, a design of oil passing through a rotor assembly of the motor is generally adopted, for example, a scheme of cross circulation oil cooling is adopted, which specifically comprises the steps that an oil passage is arranged on a rotating shaft of the motor, oil passing through the oil passage passes through an oil passage formed by a balance disc of the motor and one end of a rotor core, then cooling oil enters a through hole (such as a lightening hole) extending along the axial direction on the rotor core, flows from one end of a rotor of the motor to the other end, and finally flows to a stator winding of the motor through an oil injection hole arranged on the balance disc at the other end, so that cooling of the whole rotor assembly is completed. However, there are certain clearances between the rotor core and the end face of the balancing disk due to machining and assembling, etc., and under the condition of high-speed rotation, part of the cooling oil can enter through the clearances into the through holes on the rotor core which are not used for oil passage, and the cooling oil accumulates in the lightening holes over time to cause the problem of lightening hole accumulation, so that the balance of the rotor is problematic under the working condition of high-speed rotation, and further the NVH problem of the motor is caused.

Disclosure of Invention

To overcome the problems in the related art, the present disclosure provides a balance disc for a motor, a rotor assembly, a motor, and a vehicle.

According to a first aspect of embodiments of the present disclosure, there is provided a balance disc for an electric motor, the balance disc being provided thereon with a first oil drain groove provided on a first end face of the balance disc for facing a rotor core and for communicating with at least a first through hole of a plurality of first through holes located on the end face of the rotor core;

the balance disc is further provided with a first oil drain hole, the first oil drain hole is communicated with the first end face and a second end face, opposite to the first end face, of the balance disc, and the first oil drain hole is used for being communicated with a first through hole which is not communicated with the first oil drain groove in the plurality of first through holes;

the first through hole extends along the axial direction of the rotor core and is communicated with the two end faces of the rotor core.

Optionally, the position of the first oil drain hole on the balance disc is set such that a part of the projection of the first oil drain hole on the end face of the rotor core is located outside the corresponding first through hole in the radial direction of the rotor core.

Optionally, the shape of the first oil drain hole is set to be the same as the shape of the circular first through hole, and the maximum circumcircle radius of the first oil drain hole is larger than the maximum circumcircle radius of the corresponding first through hole.

Optionally, the number of the first oil drain holes is multiple, and the multiple first oil drain holes are in one-to-one correspondence with the multiple first through holes which are not communicated with the first oil drain groove.

Optionally, the plurality of first oil drain holes are arranged on the balance disc at equal angle intervals around the central axis of the balance disc.

Optionally, a second oil drain hole is further formed in the balance disc, the second oil drain hole is communicated with the first end face and the second end face, and the second oil drain hole is used for being communicated with a second through hole located on the end face of the rotor core;

the second through hole extends along the axial direction of the rotor core and is communicated with the two end faces of the rotor core.

Optionally, the position of the second oil drain hole on the balance disc is set such that a part of the projection of the second oil drain hole on the end face of the rotor core is located outside the corresponding second through hole in the radial direction of the rotor core.

Optionally, the shape of the second oil drain hole is set to be the same as the shape of the circular second through hole, and the maximum circumcircle radius of the second oil drain hole is larger than the maximum circumcircle radius of the corresponding second through hole.

Optionally, the number of the second oil drain holes is multiple, and the multiple second oil drain holes are used for being in one-to-one correspondence with the multiple second through holes.

Optionally, central axes of the first oil drain hole and the second oil drain hole are parallel to a central axis of the balance disc; or,

the central axes of the first oil drain hole and the second oil drain hole are arranged at an angle with the central axis of the balance disc.

Optionally, the balance disc is further provided with a first mounting hole for passing through a rotating shaft of the motor;

the inner end of the first oil drain groove extends to be communicated with the first mounting hole along the radial direction of the balance disc, and the position of the outer end of the first oil drain groove on the balance disc is set to be that the projection on the end face of the rotor core corresponds to a first through hole used for oil feeding in a plurality of first through holes so as to be communicated with the corresponding first through holes.

Optionally, the number of the first oil drain grooves is set to be plural, the plural first oil drain grooves are arranged on the balance disc at equal angle intervals around the central axis of the first mounting hole, and the number of the first oil drain grooves is smaller than the number of the first through holes.

According to a second aspect of the disclosed embodiments, a rotor assembly is provided, including a rotor core, a rotating shaft, and two balancing discs according to the above, wherein the two balancing discs and the rotor core are all sleeved on the rotating shaft, and the two balancing discs are respectively arranged at two ends of the rotor core in the axial direction.

Optionally, the rotor assembly includes a plurality of magnetic steel units, two corresponding magnetic steel units form a magnetic pole pair, a second mounting hole for a rotating shaft to pass through is formed in the rotor core, and the plurality of magnetic steel units are arranged on the end face of the rotor core at equal intervals around the central axis of the second mounting hole;

the rotor core is provided with a first through hole and a second through hole which extend along the axial direction of the rotor core, and the number of the first through hole and the second through hole and the number of the magnetic pole pairs meet the following relation;

S＝n×2N

s is the number of the first through holes or the second through holes, N is the number of the magnetic pole pairs, and N and N are positive integers.

According to a third aspect of embodiments of the present disclosure, there is provided an electric machine comprising a rotor assembly as described above.

According to a fourth aspect of embodiments of the present disclosure, there is provided a vehicle including the above-described motor.

The technical scheme provided by the embodiment of the disclosure can comprise the following beneficial effects:

through the technical scheme, when the balance disc provided by the disclosure is applied to the rotor assembly of the motor, the first oil drain hole can be configured into the cooling oil release channel communicated with the first through hole, so that cooling oil entering the first through hole which is not communicated with the first oil drain groove (namely, the first through hole which is not used for oil passing) can be discharged out of the rotor assembly through the cooling oil release channel in the process of cross circulation cooling, thereby effectively solving the problem of oil accumulation of the first through hole which is not used for oil passing, and further being beneficial to avoiding the NVH problem caused by the oil accumulation of the first through hole. Thus, the NVH performance of the motor, in particular, the first order noise performance of the motor, can be improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure.

FIG. 1 is a schematic perspective view of a balance disc according to an exemplary embodiment;

FIG. 2 is a schematic perspective view of another view of a balance disc according to an exemplary embodiment, wherein a first oil drain groove is shown, and wherein two oil drain grooves are not shown;

FIG. 3 is a schematic front view of a balance disc shown according to an exemplary embodiment;

FIG. 4 is a schematic perspective view of a rotor assembly, not shown with a rotating shaft, showing fuel injection ports and arrows showing some of the oil drain passages of the rotor assembly, according to an exemplary embodiment;

fig. 5 is a schematic perspective view of a rotor core according to an exemplary embodiment;

FIG. 6 is a schematic perspective view of a rotor assembly with balance discs removed, showing a shaft, according to an example embodiment.

Description of the reference numerals

100-rotor assembly; 10-balancing discs; 11-a first end face; 12-a second end face; 13-a first oil drain groove; 14-a first oil drain hole; 15-a second oil drain hole; 16-a first mounting hole; 17-an oil injection port; 20-rotor core; 21-a first through hole; 22-a second through hole; 23-end faces of the rotor core; 24-a second mounting hole; 30-rotating shaft; 31-an oil hole; 40-magnetic steel units; 41-magnetic steel.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples are not representative of all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present disclosure as detailed in the accompanying claims.

It should be noted that, all actions of acquiring signals, information or data in the present utility model are performed under the condition of conforming to the corresponding data protection rule policy of the country of the location and obtaining the authorization given by the owner of the corresponding device.

In this disclosure, unless otherwise indicated, the terms "inner" and "outer" are used in the orientation of the respective component's own outline, both inside and outside. Furthermore, in the present disclosure, unless otherwise indicated, terms such as "first" and "second" are used merely to distinguish one element from another element and are not of sequential or importance.

As shown in fig. 1 to 4, the present disclosure provides a balance disc 10 for an electric motor, on which balance disc 10 a first oil drain groove 13 is provided, the first oil drain groove 13 is provided on a first end face 11 of the balance disc 10 for facing a rotor core 20, and is used to communicate with at least one of a plurality of first through holes 21 located on an end face 23 of the rotor core, that is, the first oil drain groove 13 is used to communicate with a first through hole 21 for oil running out of the plurality of first through holes 21, on which balance disc 10 a first oil drain hole 14 is further provided, the first oil drain hole 14 communicates with the first end face 11 and a second end face 12 of the balance disc 10 opposite to the first end face 11, and the first oil drain hole 14 is used to communicate with a first through hole 21 not communicating with the first oil drain groove 13, that is, of the plurality of first through holes 21 is used to communicate with a first through hole 21 not for oil running out of the plurality of first through holes 21. The first through hole 21 is a through hole that extends in the axial direction of the rotor core 20 and communicates with both end surfaces of the rotor core 20.

Here, the first through hole 21 may be a through hole designed for weight reduction, or may be a through hole designed for electromagnetic scheme requirements of the motor, which is not limited in the present disclosure.

When cooling is performed, referring to fig. 4, the cooling oil may enter the hollow portion of the rotating shaft 30 in the axial direction of the motor, and then the cooling oil enters between one of the balance discs 10 of the rotor assembly 100 and one end of the rotor core 20 through the oil hole 31 on the circumferential wall of the rotating shaft 30; then, a part of the cooling oil may flow from one end of the rotor core 20 to the other end through the first oil drain groove 13 and the first through hole 21 communicating with the first oil drain groove 13, and be sprayed from the oil spray port 17 on the balance disc 10 located at the other end of the rotor core 20; while a portion of the cooling oil may be discharged through the first and second oil discharge holes 14 and 15 (see below) on the balance disc 10 to form cross oil cooling.

Through the above technical solution, when the balance disc 10 provided by the present disclosure is applied to the rotor assembly 100 of the motor, the first oil drain hole 14 may be configured as a cooling oil release channel that is in communication with the first through hole 21, so that during the cross-circulation cooling process, the cooling oil that enters into the first through hole 21 that is not in communication with the first oil drain groove 13 (i.e., the first through hole 21 that is not used for oil running) may be drained out of the rotor assembly 100 through the cooling oil release channel, thereby effectively solving the problem of oil accumulation of the first through hole 21 that is not used for oil running in the plurality of first through holes 21, and further being beneficial to avoid the NVH problem caused by the oil accumulation of the portion of the first through hole 21. Thus, the NVH performance of the motor, in particular, the first order noise performance of the motor, can be improved.

In order to enable the cooling oil in the first through holes 21 that are not used for the oil traveling to be sufficiently discharged, alternatively, as shown in fig. 3 and 5, in one embodiment of the present disclosure, the positions of the first oil discharge holes 14 on the balance disc 10 are set so that a part of the projection of the first oil discharge holes 14 on the end face 23 of the rotor core can be located outside the corresponding first through holes 21 in the radial direction of the rotor core 20. That is, the projection of each first oil drain hole 14 on the end face 23 of the rotor core in the radial direction of the rotor core 20 has, in addition to a portion that coincides with the first through hole 21 to directly communicate with the first through hole 21, another portion that is located outside the first through hole 21 in the radial direction of the rotor core 20.

When the rotor assembly 100 rotates at a high speed, the cooling oil easily flows outward by centrifugal force. In the present embodiment, since the first oil discharge holes 14 have portions located outside the first through holes 21 in the radial direction of the rotor core 20, the cooling oil that has entered the first through holes 21 that are not used for oil traveling can also be effectively discharged from the corresponding first oil discharge holes 14.

As shown in fig. 1 to 5, in the case where the shape of the first oil drain hole 14 is set to be identical to the shape of the first through hole 21 having a circular shape, that is, in the embodiment where both the first through hole 21 and the first oil drain hole 14 are circular holes, the maximum radius R2 of the circumscribed circle of the first oil drain hole 14 is larger than the corresponding maximum radius R1 of the circumscribed circle of the first through hole 21 on the rotor core 20, for ensuring that the cooling oil can be smoothly drained at a high speed, so that the oil is not accumulated in the first through hole 21 which is not used for the oil leakage.

It is to be understood that the shape of the first oil drain hole 14 is not limited in this disclosure, and may be other shapes besides the circular shape shown in fig. 1 to 4, and may be specifically determined according to the shape of the first through hole 21.

In the embodiment in which the plurality of first through holes 21 (e.g., weight-reducing holes) are provided on the rotor core 20, in order to avoid the occurrence of the oil accumulation problem of the first through holes 21 that are not in communication with the first oil drain grooves 13, as shown in fig. 1 to 4, the number of the first oil drain holes 14 may be plural, and the plurality of first oil drain holes 14 and the plurality of first through holes 21 that are not in communication with the first oil drain grooves 13 may be in one-to-one correspondence, i.e., the number of the first oil drain holes 14 may be the same as the number of the first through holes 21 of the plurality of first through holes 21 that are not in communication with the first oil drain grooves 13, and the positions of the first oil drain holes 14 may correspond to the positions of the first through holes 21 of the portion, so that the oil accumulation problem in the first through holes 21 that are not in communication with the oil can be effectively avoided.

Optionally, as shown in fig. 3, a plurality of first oil drain holes 14 are arranged on the balancing disk 10 at equal angular intervals around the central axis of the balancing disk 10, so as to better correspond to the positions of the first through holes 21 on the rotor core 20, which are not used for oil running, and also facilitate the dynamic balancing of the motor by the balancing disk 10.

The number of the first oil drain holes 14 is not limited in the present disclosure, and may specifically be determined according to the number of the first through holes 21, for example, in the embodiment shown in fig. 3 and 5, the number of the first through holes 21 on the rotor core 20 is 6, and the number of the first oil drain holes 14 on the balance disc 10 may also be 6.

It is to be understood that, in another embodiment of the present disclosure, the number of the first oil drain holes 14 may be one, and the first oil drain holes 14 may be formed as annular first oil drain holes, so that oil drain of a plurality of first through holes 21 not used for oil running may be also achieved by using a single first oil drain hole 14 corresponding to the plurality of first through holes 21.

In addition, alternatively, in still another implementation of the present disclosure, a single first oil drain hole 14 may correspond to a portion of the first through holes 21 among the plurality of first through holes 21.

In the present disclosure, as shown in fig. 1 to 4, the balance disc 10 is further provided with a second oil drain hole 15, the second oil drain hole 15 communicates with the first end face 11 and the second end face 12 of the balance disc 10, and the second oil drain hole 15 is for communicating with a second through hole 22 located on an end face 23 of the rotor core, wherein the second through hole 22 is a through hole extending in an axial direction of the rotor core 20 and communicating with both end faces of the rotor core 20.

Also, here, the second through hole 22 may be a through hole designed according to the requirement of weight reduction, or may be a through hole designed according to the requirement of electromagnetic scheme of the motor, which is not limited in the present disclosure.

In order to enable the cooling oil that has entered the second through holes 22 to be sufficiently discharged, alternatively, as shown in fig. 3 and 5, in one embodiment of the present disclosure, the position of the second oil discharge holes 15 on the balance disc 10 is set such that a part of the projection of the second oil discharge holes 15 on the end face 23 of the rotor core can be located outside the corresponding second through holes 22 in the radial direction of the rotor core 20. That is, the projection of the second oil discharge hole 15 onto the end surface 23 of the rotor core 20 in the radial direction of the rotor core has, in addition to the portion overlapping the second through hole 22 to directly communicate with the second through hole 22, another portion located outside the second through hole 22 in the radial direction of the rotor core 20, so that the cooling oil that has entered into the second through hole 22 can be effectively discharged from the corresponding second oil discharge hole 15.

As shown in fig. 3 and 5, in the embodiment in which the second through hole 22 and the second oil drain hole 15 are both circular holes, the maximum circumcircle radius R4 of the second oil drain hole 15 is larger than the maximum circumcircle radius R3 of the second through hole 22 on the rotor core 20, so as to ensure that the cooling oil can be smoothly drained at a high speed, and the oil cannot be accumulated in the second through hole 22.

It is to be understood that the shape of the second oil drain hole 15 is not limited in this disclosure, and may be other shapes besides the circular shape shown in fig. 1 to 4, and may be specifically determined according to the shape of the second through hole 22.

In the embodiment in which the plurality of second through holes 22 are provided on the rotor core 20, in order to avoid the problem of oil accumulation in the second through holes 22, as shown in fig. 1 to 4, the number of the second oil drain holes 15 may be plural, and the plurality of second oil drain holes 15 are used to correspond to the plurality of second through holes 22 one by one. That is, the number of the second oil drain holes 15 may be the same as the number of the plurality of second through holes 22, and the positions of the second oil drain holes 15 may correspond to the positions of the second through holes 22, so that the problem of oil accumulation in the second through holes 22 may be effectively avoided.

In one embodiment of the present disclosure, as shown in fig. 1 to 5, the central axes of the first and second oil drain holes 14 and 15 may extend in the axial direction of the rotor core 20. In another not shown embodiment of the present disclosure, the central axes of the first and second oil drain holes 14 and 15 may be disposed at an angle to the central axis of the balance disc 10, for example, in a direction from the first end face 11 toward the second end face 12 of the balance disc 10, with the central axes of the first and second oil drain holes 14 and 15 being offset in a direction away from the central axis of the balance disc 10. So designed, after the motor is assembled in place, the cooling oil discharged from the first oil discharge hole 14 and the second oil discharge hole 15 can be discharged to the middle of the stator end portion of the motor which is more required to be cooled, instead of the root portion of the stator end portion.

As shown in fig. 1 to 4, the balance disc 10 may be further provided with a first mounting hole 16 for passing through the rotary shaft 30 of the motor, the inner end of the first oil drain groove 13 extending in the radial direction of the balance disc 10 to communicate with the first mounting hole 16, the position of the outer end of the first oil drain groove 13 on the balance disc 10 being set such that the projection on the end face 23 of the rotor core corresponds to a first through hole 21 for oil passing out of the plurality of first through holes 21 to communicate with the corresponding first through hole 21. When the balance disc 10 and the rotor core 20 are assembled in place, the oil drain grooves and the end surfaces 23 of the rotor core may collectively define an oil drain passage, the outer end of which in the radial direction communicates with the first through hole 21 for oil to flow, so that part of the cooling oil may flow from one end of the rotor core 20 to the other end of the rotor core 20 in the axial direction of the motor rotor and finally be discharged from the other end to the rotor assembly 100, forming cross oil cooling.

The present disclosure does not limit the number of first oil drain grooves 13, and alternatively, in one embodiment of the present disclosure, the number of first oil drain grooves 13 is set to be equal to the number of pole pairs on the rotor core 20, for example, referring to fig. 3, 5 and 6, the motor rotor has 6 magnetic steel units 40, the number of pole pairs is 3, and the number of first oil drain grooves 13 is 3. This arrangement facilitates more uniform injection of fuel into rotor assembly 100, thereby facilitating improved NVH performance of the motor.

The plurality of first oil drain grooves 13 may be arranged on the balance disc 10 at equal angular intervals about the central axis of the mounting hole of the rotation shaft 30, and the number of the first oil drain grooves 13 is smaller than the number of the first through holes 21.

Thus, by reasonably designing the number and positions of the oil drains, the balance of oil injection of the rotor assembly 100 is facilitated to be improved, thereby facilitating further improvement of NVH performance of the motor.

In the 3 embodiments shown in fig. 3, 3 oil drains are arranged at equal angles on the first end face 11 of the balancing disk 10.

In addition, the balance disc 10 may further have a second oil drain groove (not shown) provided on the first end surface 11, an inner end of the second oil drain groove may extend to the first mounting hole 16 in a radial direction of the balance disc 10 to communicate, an outer end of the oil drain groove extends to an outer circumferential surface of the balance disc 10, and when the balance disc 10 and the rotor core 20 are assembled in place, the oil drain groove and the end surface 23 of the rotor core may jointly define an oil drain passage, and the oil injection port 17 described above may be formed at a position of the outer end of the oil drain groove.

Alternatively, the second oil drain grooves may be arranged at intervals in the circumferential direction from the first oil drain grooves 13 on the first cross section 11 of the balance disc 10.

According to another aspect of the present disclosure, there is provided a rotor assembly 100, the rotor assembly 100 including a rotor core 20, a rotating shaft 30, and two balancing discs 10, wherein the two balancing discs 10 and the rotor core 20 are respectively sleeved on the rotating shaft 30, and the two balancing discs are respectively disposed at two ends of the rotor core 20 in an axial direction.

The rotating shaft 30 is a hollow rotating shaft 30, and an oil hole 31 is formed in a side wall of the rotating shaft 30, wherein the rotating shaft 30 penetrates through the first mounting hole 16 on the balance disc 10 and the second mounting hole 24 on the rotor core 20. When cooling, the cooling oil may enter the hollow portion of the rotating shaft 30 in the axial direction of the motor, and then the cooling oil enters between one of the balance discs 10 of the rotor assembly 100 and one end of the rotor core 20 through the oil hole 31 on the circumferential wall of the rotating shaft 30; thereafter, a part of the cooling oil may flow from one end of the rotor core 20 to the other end through the first oil drain groove 13 and the first through hole 21 communicating with the first oil drain groove 13, and be sprayed from the oil spray port 17 on the balance disc 10 located at the other end of the rotor core 20, thereby forming cross oil cooling; while a part of the cooling oil may be discharged through the first oil discharge hole 14 of the balance disc 10 and another part of the cooling oil may be discharged through the second oil discharge hole 15 of the balance disc 10.

As shown in fig. 5 and 6, the rotor assembly 100 may include a plurality of magnetic steel units 40, two corresponding magnetic steel units 40 form a magnetic pole pair, the rotor core 20 is provided with a second mounting hole 24 through which the rotating shaft 30 passes, and the plurality of magnetic steel units 40 are equally spaced on the third end surface around the central axis of the second mounting hole 24;

the number of first through holes 21 and second through holes 22 and the number of magnetic pole pairs satisfy the following relationship;

S＝n×2N

wherein S is the number of the first through holes 21 or the second through holes 22, N is the number of the magnetic pole pairs, and N are both positive integers.

As an alternative embodiment, referring to fig. 5 and 6, the motor rotor has 6 magnetic steel units 40 with 3 pairs of magnetic pole pairs, and the 6 magnetic steel units 40 are arranged on the third end face at equal intervals around the central axis of the second mounting hole 24, S being the number of lightening holes 6, i.e., n is equal to 1, n is equal to 3 in the present embodiment.

The rotor core 20 and the plurality of magnetic steel units 40 are configured into a rotor of the motor, the rotor core 20 is provided with magnetic steel grooves for installing the magnetic steel 41, each magnetic steel unit 40 can comprise two magnetic steels 41 which are arranged in a splayed shape, and the magnetic steel 41 is arranged in the corresponding magnetic steel groove.

According to a third aspect of the present disclosure, there is provided an electric machine comprising the rotor assembly 100 described above. The present disclosure is not limited to a particular type of motor, and alternatively, the motor may be a permanent magnet synchronous motor.

According to a third aspect of the present disclosure, there is provided a vehicle comprising the above-described motor. The vehicle may be a hybrid vehicle or a pure electric vehicle, and the disclosure is not limited thereto.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure. This application is intended to cover any adaptations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. The specification and examples are to be regarded in an illustrative manner only.

It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims (16)

1. A balance disc for an electric motor, characterized in that a first oil drain groove is provided on the balance disc, the first oil drain groove being provided on a first end face of the balance disc for facing a rotor core and for communicating with at least one of a plurality of first through holes located on the end face of the rotor core;

the balance disc is further provided with a first oil drain hole, the first oil drain hole is communicated with the first end face and a second end face, opposite to the first end face, of the balance disc, and the first oil drain hole is used for being communicated with a first through hole which is not communicated with the first oil drain groove in the plurality of first through holes;

the first through hole extends along the axial direction of the rotor core and is communicated with the two end faces of the rotor core.

2. The balance disc according to claim 1, wherein the position of the first oil drain hole on the balance disc is set such that a part of the projection of the first oil drain hole on the end face of the rotor core is located outside the corresponding first through hole in the radial direction of the rotor core.

3. The balance disc according to claim 2, wherein the shape of the first oil drain hole is set to be the same as the shape of the first through hole having a circular shape, and a maximum radius of the circumscribed circle of the first oil drain hole is larger than a maximum radius of the circumscribed circle of the first through hole.

4. The balance disc according to claim 1, wherein the number of the first oil drain holes is plural, and the plural first oil drain holes and the plural first through holes which do not communicate with the first oil drain groove are in one-to-one correspondence.

5. The balance disc of claim 1, wherein a plurality of the first oil drain holes are arranged on the balance disc at equal angular intervals about a central axis of the balance disc.

6. The balance disc according to claim 1, further provided with a second oil drain hole communicating the first end face and the second end face, and for communicating with a second through hole located on an end face of the rotor core;

the second through hole extends along the axial direction of the rotor core and is communicated with the two end faces of the rotor core.

7. The balance disc according to claim 6, wherein the position of the second oil drain hole on the balance disc is set such that a part of the projection of the second oil drain hole on the end face of the rotor core is located outside the corresponding second through hole in the radial direction of the rotor core.

8. The balance disc according to claim 7, wherein the shape of the second oil drain hole is set to be the same as the shape of the second through hole having a circular shape, and a maximum radius of the circumscribed circle of the second oil drain hole is larger than a maximum radius of the circumscribed circle of the second through hole.

9. The balance disc according to claim 6, wherein the number of the second oil drain holes is plural, and the plural second oil drain holes are used in one-to-one correspondence with the plural second through holes.

10. The balance disc according to claim 6, wherein central axes of the first oil discharge hole and the second oil discharge hole are parallel to a central axis of the balance disc; or,

the central axes of the first oil drain hole and the second oil drain hole are arranged at an angle with the central axis of the balance disc.

11. Balance disc according to any of claims 1-10, characterized in that the balance disc is further provided with a first mounting hole for passing the rotation shaft of the motor;

the inner end of the first oil drain groove extends to be communicated with the first mounting hole along the radial direction of the balance disc, and the position of the outer end of the first oil drain groove on the balance disc is set to be that the projection on the end face of the rotor core corresponds to a first through hole used for oil feeding in a plurality of first through holes so as to be communicated with the corresponding first through holes.

12. The balance of claim 11, wherein the number of first oil drains is a plurality, the plurality of first oil drains are equally angularly spaced on the balance about a central axis of the first mounting hole, and the number of first oil drains is less than the number of first through holes.

13. A rotor assembly comprising a rotor core, a rotating shaft and two balancing discs according to any one of claims 1-12, wherein the two balancing discs and the rotor core are sleeved on the rotating shaft, and the two balancing discs are respectively arranged at two ends of the rotor core in the axial direction.

14. The rotor assembly of claim 13, wherein the rotor assembly comprises a plurality of magnetic steel units, two corresponding magnetic steel units form a magnetic pole pair, a second mounting hole for a rotating shaft to pass through is formed in the rotor core, and the plurality of magnetic steel units are arranged on the end face of the rotor core at equal intervals around the central axis of the second mounting hole;

the rotor core is provided with a first through hole and a second through hole which extend along the axial direction of the rotor core, and the number of the first through hole and the second through hole and the number of the magnetic pole pairs meet the following relation;

S＝n×2N

s is the number of the first through holes or the second through holes, N is the number of the magnetic pole pairs, and N and N are positive integers.

15. An electric machine comprising a rotor assembly according to claim 13 or 14.

16. A vehicle comprising the electric machine according to claim 15.