CN114069969A

CN114069969A - Motor and vehicle

Info

Publication number: CN114069969A
Application number: CN202010768985.8A
Authority: CN
Inventors: 蒲晓敏; 王飞; 高劲军; 胡义明
Original assignee: Guangdong Welling Auto Parts Co Ltd; Anhui Welling Auto Parts Co Ltd
Current assignee: Guangdong Welling Auto Parts Co Ltd; Anhui Welling Auto Parts Co Ltd
Priority date: 2020-08-03
Filing date: 2020-08-03
Publication date: 2022-02-18
Anticipated expiration: 2040-08-03
Also published as: CN114069969B

Abstract

The invention discloses a motor which comprises a shell, a stator, a first end cover, a second end cover, a first oil injection ring, a rotor, a first end plate and a second end plate, wherein the stator is arranged in an inner cavity of the shell; the rotor includes rotor core, rotor magnet steel and pivot, is equipped with the rotor oil circuit in the rotor core, is equipped with the pivot oil circuit in the pivot, and first end plate is established in rotor core's first end, is equipped with first oil groove on the medial surface that first end plate is relative with rotor core, first oil groove respectively with pivot oil circuit and rotor oil circuit intercommunication, be equipped with the first end plate oil outlet with first oil groove and casing inner chamber intercommunication on the lateral surface of first end plate. The motor provided by the embodiment of the invention has a good heat dissipation effect, and can effectively improve the performance of the motor by performing multiple cooling particularly on a stator winding which generates heat seriously.

Description

Motor and vehicle

Technical Field

The invention relates to the technical field of motors, in particular to a motor and a vehicle.

Background

At present, a driving motor of a new energy automobile gradually tends to high power density and high speed, and higher requirements are provided for the heat dissipation capacity of the motor. The high heat of the motor directly influences the service life of the motor insulating material and the running reliability of the motor, particularly for the motor, the high temperature increases the demagnetization risk of the permanent magnet and can reduce the performance of the permanent magnet, and because the position of the stator winding end of the motor can not directly transfer heat with the outside, the temperature of the stator winding end is the highest temperature point of the whole motor.

The oil cooling mode of the motor in the related technology mainly aims at cooling the stator, and comprises that an oil way is designed in a shell, and a drainage structure is additionally arranged above a winding; or cooling oil is added into the motor in an oil bath mode, so that the rotor is immersed in the cooling oil, and the oil is thrown onto the motor through the rotation of the rotor for cooling; or the stator oil way and the rotor oil way are connected in series for cooling. However, the above methods have disadvantages, such as increased motor volume, complex structure, uneven motor air gap, and easy oil accumulation.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.

To this end, embodiments of the first aspect of the present invention propose a motor with improved cooling.

An embodiment of a second aspect of the invention proposes a vehicle having the above-described electric machine.

The motor comprises a shell, wherein the shell is provided with an inner cavity, and a shell oil inlet is formed in the shell; the stator comprises a stator core and a stator winding, the stator is arranged in an inner cavity of the shell, a cooling oil duct is formed between the outer peripheral wall of the stator core and the inner peripheral wall of the shell, and the cooling oil duct is communicated with the oil inlet of the shell; the oil inlet of the first end cover is arranged at the first end of the shell, and the oil inlet of the second end cover is arranged at the second end of the shell; the first oil injection ring is arranged on the inner side of the first end cover, an oil injection space communicated with the cooling oil duct is formed between the outer peripheral wall of the first oil injection ring and the inner peripheral wall of the shell, a plurality of first oil injection holes are formed in the first oil injection ring and are arranged at intervals in the circumferential direction of the first oil injection ring, and the first oil injection holes are communicated with the oil injection space and used for injecting cooling oil from the outer periphery of the stator towards the first end of the stator winding; the rotor comprises a rotor core, rotor magnetic steel and a rotating shaft, a rotor oil path is arranged in the rotor core, a rotating shaft oil path is arranged in the rotating shaft, a rotating shaft oil inlet and a rotating shaft oil outlet which are communicated with the rotating shaft oil path are arranged on the rotating shaft, a first end of the rotating shaft penetrates through the first end cover to extend out of the shell, and the rotating shaft oil inlet is communicated with the end cover oil inlet; the first end plate is arranged at the first end of the rotor core and matched with the rotating shaft, a first oil groove is arranged on the inner side surface of the first end plate opposite to the rotor core and is respectively communicated with the rotating shaft oil outlet and the rotor oil way, and a first end plate oil outlet for communicating the first oil groove with the inner cavity of the shell is arranged on the outer side surface of the first end plate; the second end plate, the second end plate is established rotor core's second end and with the pivot cooperation, the second end plate with be equipped with the second oil groove on the medial surface that rotor core is relative, the second oil groove with rotor oil circuit intercommunication, the lateral surface of second end plate be equipped with be used for with the second oil groove with the second end plate oil outlet of the inner chamber intercommunication of casing.

According to the motor provided by the embodiment of the invention, the flowing path of the cooling liquid is long, the cooling effect on the shell, the stator and the rotor is good, especially for the stator winding with serious heating, multiple cooling is carried out on the motor through the first oil injection hole, the first end plate oil outlet hole and the second end plate oil outlet hole, the cooling performance of the motor is higher, meanwhile, the rotor magnetic steel can be effectively cooled, the temperature rise of the magnetic steel is reduced, and the output performance of the motor under a high-speed working condition is improved. The motor according to the embodiment of the invention can exert larger torque and power for the same volume of the motor.

In some embodiments, the motor further includes a second oil injection ring, the second oil injection ring is disposed inside the second end cover, an oil injection space communicated with the cooling oil passage is formed between an outer peripheral wall of the second oil injection ring and an inner peripheral wall of the casing, a plurality of second oil injection holes are disposed on the second oil injection ring at intervals in a circumferential direction of the second oil injection ring, and the second oil injection holes are communicated with the oil injection space and used for injecting cooling oil from an outer periphery of the stator toward the second end of the stator winding.

In some embodiments, the first spray ring is removably mounted on or integrally formed with the first end cap and/or the second spray ring is removably mounted on or integrally formed with the second end cap.

In some embodiments, the cross section of each first oil injection hole is circular, and the cross section area of the first oil injection hole at the high position is larger than that of the first oil injection hole at the low position in two adjacent first oil injection holes; and/or the cross section of the second oil injection hole is circular, and the cross section area of the higher second oil injection hole is larger than that of the lower second oil injection hole in two adjacent second oil injection holes.

In some embodiments, the first oil injection ring is divided into a first upper ring section located above the center of the first oil injection ring and a first lower ring section located below the center of the first oil injection ring, the cross-sectional area of the first oil injection hole in the first upper ring section gradually increases in the radial direction of the first oil injection ring along the outside-in direction, and the cross-sectional area of the first oil injection hole in the first lower ring section gradually decreases in the radial direction of the first oil injection ring along the outside-in direction; and/or the second oil injection ring is divided into a second upper ring section located above the center of the second oil injection ring and a second lower ring section located below the center of the second oil injection ring, the cross-sectional area of a second oil injection hole in the second upper ring section is gradually increased in the radial direction of the second oil injection ring along the direction from outside to inside, and the cross-sectional area of a second oil injection hole in the second lower ring section is gradually decreased in the radial direction of the second oil injection ring along the direction from outside to inside.

In some embodiments, the first oil groove includes a first connecting groove, a first guide groove and a first oil outlet groove, a first end of the first connecting groove is communicated with the rotating shaft oil outlet, a second end of the first connecting groove is communicated with the first guide groove, a first end of the first oil outlet groove is communicated with the first guide groove, and a second end of the first oil outlet groove is communicated with the first end plate oil outlet; the second oil groove comprises a second annular groove and a second oil outlet groove, the second annular groove is communicated with the rotor oil way, the first end of the second oil outlet groove is communicated with the second annular groove, and the second end of the second oil outlet groove is communicated with the second end plate oil outlet hole.

In some embodiments, the first connecting groove is offset from the first oil outlet groove in a radial direction of the first end plate.

In some embodiments, the first connecting grooves are plural and are arranged at intervals along the circumferential direction of the first end plate, the first connecting grooves extend along the radial direction of the first end plate, the first oil outlet grooves are plural and are arranged at intervals along the circumferential direction of the first end plate, and the first oil outlet grooves extend along the radial direction of the first end plate;

the second oil outlet groove is a plurality of and is arranged along the circumferential interval of the second end plate, and the second oil outlet groove is arranged along the radial extension of the second end plate.

In some embodiments, the outlet wires of the stator winding extend from one side of the second end cover, the number of the first end plate oil outlet holes is N1 and the first end plate oil outlet holes are uniformly arranged along the circumferential direction of the first end plate, the number of the second end plate oil outlet holes is N2 and the second end plate oil outlet holes are uniformly arranged along the circumferential direction of the second end plate, wherein N1 < N2.

In some embodiments, the number of first end plate oil outlet holes is less than the number of second end plate oil outlet holes.

In some embodiments, the first end plate oil outlet hole has a smaller diameter than the second end plate oil outlet hole.

In some embodiments, the opening direction of the outlet end of the first end plate oil outlet hole and the opening direction of the outlet end of the second end plate oil outlet hole are both towards the stator.

In some embodiments, the outer circumferential wall of the stator core is provided with a stator groove and/or a cut edge extending in an axial direction of the stator core, and the cooling oil passage is formed by the stator groove and/or the cut edge.

In some embodiments, the peripheral wall of the stator core is provided with at least one stator circumferential groove extending along the circumferential direction of the stator core, so that the stator core is divided into a plurality of non-groove core segments and at least one groove core segment along the axial direction of the stator core, and the peripheral wall of the non-groove core segment is provided with stator grooves and/or cut edges extending along the axial direction of the stator core and distributed at intervals along the circumferential direction of the stator core.

In some embodiments, the stator grooves are rectangular, and the depth of the stator grooves satisfies the relationship:

wherein a is the depth of the stator groove, Rout is the outer diameter of the stator, Rin is the inner diameter of the stator, L is the yoke thickness of the stator, h is the stack thickness of the stator, and k1 is a coefficient and is 0.05-0.1.

In some embodiments, the depth of the cut edge satisfies the relation

Wherein b is the depth of the cut edge, Rout is the outer diameter of the stator, Rin is the inner diameter of the stator, L is the yoke thickness of the stator, h is the stack thickness of the stator, and k1 is a coefficient and is 0.05-0.1.

In some embodiments, the plurality of the machine shell oil inlets are distributed along the circumferential direction of the machine shell, the included angle α between the central axes of the adjacent machine shell oil inlets is less than or equal to 180 degrees, and the central angle β between the center of the machine shell oil inlet and the projection of the center of the nearest trimming edge of the machine shell oil inlet on the cross section of the stator core is 0-5 degrees.

A vehicle according to an embodiment of the second aspect of the invention comprises an electric machine according to an embodiment of the first aspect of the invention.

Drawings

FIG. 1 is a schematic diagram of an electric machine according to an embodiment of the invention;

FIG. 2 is a schematic view of a rotor and a shaft according to an embodiment of the present invention;

FIG. 3 is a schematic view of a spindle according to an embodiment of the present invention;

FIG. 4 is a schematic view of a chassis according to an embodiment of the invention;

FIG. 5 is a schematic view of a first end cap according to an embodiment of the invention;

FIG. 5a is a cross-sectional view of a first end cap according to an embodiment of the present invention;

FIG. 5b is a partial view A of a cross-sectional view of a first end cap according to an embodiment of the present invention;

FIG. 5c is a partial view B of a cross-sectional view of the first end cap according to an embodiment of the present invention;

FIG. 6 is a schematic view of a second end cap according to an embodiment of the invention;

FIG. 6a is a cross-sectional view of a second end cap according to an embodiment of the present invention;

FIG. 6b is a partial view C of a cross-sectional view of a second end cap according to an embodiment of the present invention;

FIG. 6c is a partial view D of a cross-sectional view of a second end cap according to an embodiment of the present invention;

FIG. 7 is a schematic view of a first end plate according to an embodiment of the invention;

FIG. 8 is another schematic view of the first end plate according to an embodiment of the invention;

FIG. 9 is a schematic view of a second end plate according to an embodiment of the invention;

FIG. 10 is another schematic view of a second end plate according to an embodiment of the invention;

fig. 11 is a schematic view of a stator core according to an embodiment of the invention;

fig. 12 is a schematic view of a stator core according to another embodiment of the present invention;

fig. 13 is a partial schematic view of a stator lamination of a stator core according to an embodiment of the invention;

fig. 14 is a schematic view of a stator lamination of a stator core according to an embodiment of the invention;

FIG. 15 is a schematic view of a chassis according to another embodiment of the invention;

FIG. 16 is a schematic view of a chassis according to yet another embodiment of the invention;

FIG. 17 is a graphical illustration of the coefficient K1 versus voltage drop and maximum temperature rise of a motor according to an embodiment of the present invention;

FIG. 18 is a graphical illustration of the coefficient K2 versus voltage drop and maximum temperature rise of a motor according to an embodiment of the present invention;

FIG. 19 is a schematic diagram illustrating a relationship between a projected central angle β of a center of an oil inlet of a housing and a projected center of a trimming edge and a maximum temperature rise rate of a motor according to an embodiment of the present invention;

FIG. 20 is a schematic view of a first endcap, according to another embodiment of the present invention;

FIG. 21 is a schematic view of a second endcap, according to another embodiment of the present invention.

Reference numerals:

1. a rotor core; 11. a rotor oil path;

2. a rotating shaft; 21. a rotating shaft oil circuit; 22. an oil inlet of the rotating shaft; 23. an oil outlet of the rotating shaft;

3. a first end plate; 31. a first connecting groove; 32. a first guide groove; 33. a first oil outlet groove; 34. the first end plate is provided with an oil outlet;

4. a second end plate; 41. a second communicating groove 42, a second annular groove; 43. a second oil outlet groove; 44. the second end plate is provided with an oil outlet;

5. a stator core; 51. a cooling oil passage; 52. a stator groove; 53. trimming; 54. a stator circumferential groove;

6. a first end cap; 61. a first oil spray ring; 611. a first oil jet hole;

7. a second end cap; 71. a second spray ring; 711. a second oil jet hole; 72. an end cover oil inlet;

8. a housing; 81. an oil inlet of the machine shell.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

As shown in fig. 1 to 2 and 4, the motor according to the embodiment of the present invention includes a housing 8, a first end cover 6, a second end cover 7, a stator, and a rotor. The housing 8 has an inner cavity for accommodating components such as a stator and a rotor.

The first end cap 6 is provided at a first end (left end in fig. 1) of the casing 8, and the first oil jet ring 61 is provided inside the first end cap 6. The second end cap 7 is disposed at the second end 9 (the right end in fig. 1) of the casing 8, and the second end cap 7 is opened with an end cap oil inlet 72. The stator is composed of a stator core 5 and a stator winding, the stator winding is wound on the stator core 5, a cooling oil channel 51 is arranged between the outer peripheral wall of the stator core 5 and the inner peripheral wall of the machine shell 8, and the machine shell 8 is provided with a machine shell oil inlet 81 communicated with the cooling oil channel 51.

The rotor comprises rotor core 1, rotor magnet steel and pivot 2, and the rotor is established in the casing and is spaced apart from the stator, and the rotor is established in the inboard of stator, is equipped with rotor oil circuit 11 in the rotor core 1.

As shown in fig. 5, an oil injection space communicating with the cooling oil passage 51 is formed between the outer circumferential wall of the first oil injection ring 61 and the inner circumferential wall of the casing 8, a plurality of first oil injection holes 611 arranged at intervals in the circumferential direction of the first oil injection ring 61 are provided on the first oil injection ring 61, and the first oil injection holes 611 communicate with the oil injection space to inject the cooling oil from the outer circumference of the stator toward the first end of the stator winding.

As shown in fig. 3, the rotating shaft 2 penetrates through the rotor core 1 and is matched with the rotor core 1, a rotating shaft oil path 21 is arranged in the rotating shaft 2, a rotating shaft oil inlet 22 and a rotating shaft oil outlet 23 are arranged on the rotating shaft 2, both the rotating shaft oil inlet 22 and the rotating shaft oil outlet 23 are communicated with the rotating shaft oil path 21 for oil outlet and oil inlet, a first end of the rotating shaft 2 penetrates through the first end cover 6 and extends out of the housing 8 to serve as an output shaft of the motor, the rotating shaft oil inlet 22 is communicated with an end cover oil inlet 72 arranged on the second end cover 7, it should be noted that the rotating shaft oil inlet 22 is not directly communicated with the end cover oil inlet 72, but a certain gap exists, so as to avoid the contact between the rotating shaft 2 and the second end cover 7, thereby generating friction force and affecting the normal rotation of the rotating shaft, and cooling oil is injected into the rotating shaft oil inlet 22 through the end cover oil inlet 72 and enters the rotating shaft oil path.

The motor further comprises a first end plate 3 and a second end plate 4, the first end plate 3 is arranged at the first end of the rotor core 1, the first end plate is sleeved on the rotating shaft 2, a first oil groove is arranged on the inner side face of the first end plate 3, the inner side face refers to the face opposite to the rotor core 1, the first oil groove is respectively communicated with the rotating shaft oil outlet 23 and the rotor oil way 11, a first end plate oil outlet 34 communicated with the first oil groove and the inner cavity of the shell 8 is arranged on the outer side face of the first end plate 3, it can be understood that the first end plate oil outlet 34 is a through hole, the first end plate oil outlet 34 penetrates through the first end plate 3 along the thickness direction of the first end plate, and one end of the first end plate oil outlet 34 is communicated with the first oil groove.

Similarly, the second end plate 4 is arranged at the second end of the rotor core 1 and sleeved on the rotating shaft 2, the inner side surface of the second end plate 4 is provided with a second oil groove, the second oil groove is communicated with the rotor oil path 11, the second end plate 4 is provided with a second end plate oil outlet 44, and the second end plate oil outlet 44 is communicated with the second oil groove.

The motor comprises three cooling oil paths, namely a cooling oil path, a rotor oil path and a rotating shaft oil path, wherein the cooling oil path mainly cools the shell, the stator core and the stator winding, and the rotor oil path and the rotating shaft oil path cool and dissipate heat of the rotor core, the rotor magnetic steel and the stator winding.

Specifically, the cooling oil enters the cooling oil flow channel through the housing oil inlet 81, firstly cools the stator core 5 and the housing 8, then flows to the first end of the stator core 5, enters the oil injection space, and enters the first oil injection hole 611 through the oil injection space, and the cooling oil can be sprayed out through the first oil injection hole 611 under the action of external pressure and gravity, so as to spray the cooling oil to the first end of the stator winding, and thus the first end of the stator winding is cooled.

The rotating shaft oil path 21 is communicated with the rotor oil path 11 through a rotating shaft oil outlet 23, the communication is indirect communication, cooling oil firstly cools and dissipates heat of the rotating shaft 2 after entering the rotating shaft oil path 21, then the cooling oil flows into a first oil groove from a rotating shaft oil outlet, part of the cooling oil is thrown into an inner cavity of a first end of the machine shell 8 through a first end plate oil outlet 34 under the action of centrifugal force, so that a stator winding in the inner cavity is cooled, the rest of the cooling oil enters the rotor oil path 11 through the first oil groove, so that the rotor iron core 1 and rotor magnetic steel are cooled, the cooling oil flows into a second oil groove of a second end plate through the rotor oil path 11, and is thrown into an inner cavity of a second end of the machine shell 8 through a second end plate oil outlet 44 and cools the stator winding, and finally the cooling oil in the inner cavity of the machine shell 8 enters an oil return pipeline through an end cover oil outlet (not shown), and after cooling, the oil enters each oil way again. It should be noted that, because the rotating shaft and the rotor core 1 rotate, the cooling oil entering the inner cavity of the casing 8 through the first end plate oil outlet hole 34 and the second end plate oil outlet hole 44 is thrown into the inner cavity of the casing, so that the stator winding located on the outer peripheral side of the rotor core 1 can be cooled better, and the cooling effect is improved.

According to the motor provided by the embodiment of the invention, the cooling liquid oil passage, the rotating shaft oil passage and the rotor oil passage are arranged, the flowing path of the cooling liquid is long, the cooling effect on the shell, the stator and the rotor is good, particularly for a stator winding with serious heating, the first oil injection hole, the first end plate oil outlet hole and the second end plate oil outlet hole 44 are used for carrying out multiple cooling on the motor, the heat dissipation performance of the motor is better, meanwhile, rotor magnetic steel can be effectively cooled, the temperature rise of the magnetic steel is reduced, and the output performance of the motor under a high-speed working condition is improved. The motor according to the embodiment of the present invention can have a larger torque and power for the same volume of the motor.

As shown in fig. 6, in some embodiments, a second oil jet ring 71 is provided inside the second end cap 7, and similarly, an oil jet space communicating with the cooling oil passage 51 is formed between the outer circumferential wall of the second oil jet ring 71 and the inner circumferential wall of the casing 8, and a plurality of second oil jet holes 711 arranged at intervals in the circumferential direction of the second oil jet ring 71 are provided on the second oil jet ring 71, and the second oil jet holes 711 communicate with the oil jet space for injecting the cooling oil from the outer circumference of the stator toward the second end of the stator winding.

The liquid outlet end of the cooling oil duct 51 is located at the end of the stator core 5 and is communicated with the oil injection spaces at the two ends, and the cooling oil enters the first oil injection hole 611 and the second oil injection hole 711 through the first oil injection ring 61 and the second oil injection ring 71 respectively and is injected from the first oil injection hole 611 and the second oil injection hole 711. From this, first oil spout ring 61 cools off stator winding's first end, and second oil spout ring 71 cools off stator winding's second end, and whole cooling effect is better, and cooling efficiency can be adjusted through the pressure and the flow of outside cooling oil, has avoided getting rid of the problem that cooling efficiency is low that oil leads to through motor speed control, and the controllability is high. In addition, the cooling oil channel 51 directly conveys the cooling oil to the end part of the stator winding, so that the cooling pertinence is strong, and the cooling effect and the motor performance are further improved.

In some embodiments, the first oil injection ring 61 is detachably connected to the first end cap 6, and the first oil injection ring 61 is detachably mounted on the inner side surface of the first end cap 6. The second injection ring 71 is detachably mounted on the inner side of the second end cap 7. Alternatively, the first injection ring 61 can also be mounted on the inner side of the first end cap 6 in a non-removable manner after being separately machined, and the second injection ring 71 can be mounted on the inner side of the second end cap 7 in a non-removable manner after being separately machined.

In some embodiments, the first oil spray ring 61 is integrally formed with the first end cap 6. The second oil injection ring 71 is integrally formed with the second end cap 7, so that the structure is stable, the strength is high, the oil injection ring can bear higher pressure, and the reliability is high.

As shown in fig. 20 and 21, in some embodiments, the cross section of each first oil jet 611 is circular, and the cross section area of the first oil jet 611 located at a higher position is larger than the cross section area of the first oil jet 611 located at a lower position in two adjacent first oil jets 611. Similarly, the cross section of the second oil injection hole 711 is circular, and the cross section area of the second oil injection hole 711 at a high position is larger than that of the second oil injection hole 711 at a low position in two adjacent second oil injection holes 711.

Because the oil inlet 81 of the housing is located at the top of the housing 8, the pressure of the first oil injection hole 611 and the second oil injection hole 711 close to the upper part is higher, and the pressure of the lower part is lower, so that the balance of the spraying of the cooling oil can be ensured and the cooling effect can be improved by arranging the cross-sectional areas of the first oil injection hole 611 and the second oil injection hole 711 as described above.

As shown in fig. 5a, 5b and 5c, in some embodiments, the first oil spray ring 61 is divided into a first upper ring segment located above the center of the first oil spray ring and a first lower ring segment located below the center of the first oil spray ring. The cross-sectional area of the first oil injection hole 611 on the first upper ring segment is gradually increased along the direction from outside to inside in the radial direction of the first oil injection ring, that is, the first oil injection hole 611 on the first upper ring segment is a cone which is gradually enlarged from outside to inside, the cross-sectional area of the first oil injection hole on the first lower ring segment is gradually reduced along the direction from outside to inside in the radial direction of the first oil injection ring, that is, the first oil injection hole 611 on the first lower ring segment is a cone which is gradually reduced from outside to inside. Similarly, as shown in fig. 6a, 6b and 6c, the second oil injection ring 71 is divided into a second upper ring segment located above the center of the second oil injection ring and a second lower ring segment located below the center of the second oil injection ring. The cross-sectional area of the second oil spout hole on the second upper ring section increases gradually along the direction from outside to inside in the radial direction of this second oil spout ring, and the second oil spout hole 711 on the second upper ring section is the toper that enlarges gradually from outside to inside, and the cross-sectional area of the second oil spout hole on the second lower ring section reduces gradually along the direction from outside to inside in the radial direction of second oil spout ring, and the second oil spout hole 711 on the second lower ring section is the toper that reduces gradually from outside to inside.

Therefore, the first oil injection hole and the second oil injection hole in the first upper ring section and the second upper ring section are small in outside and large in inside, the cooling liquid on the upper side flows to the end portion of the stator winding through the tapered holes under the action of gravity as a leading action force, the injection range is enlarged, and the cooling liquid can fully contact the end portion of the stator winding. The shapes of the first oil injection hole and the second oil injection hole which are positioned in the first upper ring section and the second upper ring section are large outside and small inside, and the cooling liquid on the lower side is cooled by being injected to the outer side of the end part of the stator winding after passing through the inverted cone-shaped hole under the condition that the external pressure is the dominant acting force, so that the cooling effect is further improved.

As shown in fig. 7 and 8, in some embodiments, the first oil groove includes a first communication groove 31, a first guide groove 32, and a first oil outlet groove 33, a first end of the first communication groove 31 communicates with the rotating shaft oil outlet hole 23, and a second end of the first communication groove 31 communicates with the first guide groove 32. The first guide groove 32 is preferably annular. The cooling oil in the rotating shaft oil path 21 enters the first connecting groove 31 through the rotating shaft oil outlet 23, flows from the first end of the first connecting groove 31 to the second end, flows into the first guide groove 32 from the second end of the first connecting groove 31, enters the first end of the first oil outlet groove 33 through the first guide groove 32, is sprayed out through the second end of the first oil outlet groove 33 and the first end plate oil outlet 34, and the rest of the cooling oil enters the rotor oil path 11 through the first guide groove 32 and flows to the second oil groove.

As shown in fig. 9 and 10, the second oil groove includes a second guide groove 42 and a second oil outlet groove 43, the second guide groove 42 communicates with the rotor oil passage 11, and the second guide groove 42 is preferably annular. The second end of the second oil outlet groove 43 communicates with the second end plate oil outlet hole 44. The cooling oil in the rotor oil passage 11 first flows into the second guide groove 42, flows into the first end of the second oil outlet groove 43 through the second guide groove 42, and is finally thrown out through the oil outlet hole 44 of the second end plate 4.

It should be noted that, in the above description, the first end plate 3 differs from the second end plate 4 in that the first end plate 3 has the first communicating groove 31 communicating with the spindle oil outlet hole 23, and the second end plate 4 does not have the communicating groove. However, for convenience of processing and cost reduction, for example, when the first end plate 3 and the second end plate 4 are processed, the same mold can be used for manufacturing, the second end plate 4 is also processed with the second communicating groove 41 similar to the first communicating groove 31, and since the rotating shaft is not provided with the rotating shaft oil outlet hole communicated with the second communicating groove 41, the coolant cannot enter the second communicating groove 41 from the rotating shaft oil outlet hole, thereby not affecting the normal use of the second end plate 4.

In some embodiments, the first communicating groove 31 and the first oil outlet groove 33 are staggered in the radial direction of the first end plate 3, in other words, the first communicating groove 31 and the first oil outlet groove 33 cannot be aligned with each other.

The number of the first connecting grooves 31 and the first oil outlet grooves 33 is four, the included angle between two adjacent connecting grooves is 90 degrees, the included angle between two adjacent first oil outlet grooves 33 is 90 degrees, each first connecting groove 31 is staggered with the first oil outlet groove 33 in the radial direction of the first end plate 3, the cooling oil entering the first connecting groove 31 through the rotating shaft oil outlet hole 23 can flow in the first guide groove 32 in order to ensure that each first oil outlet groove 33 can have the cooling oil to flow in the condition that the number of the rotating shaft oil outlet holes 23 is different from that of the first connecting grooves 31, but the cooling oil directly enters the first oil outlet grooves 33 from the first connecting grooves 31.

In some embodiments, the first communicating groove 31 is plural and is spaced along the circumferential direction of the first end plate 3, the first communicating groove 31 extends along the radial direction of the first end plate 3, the first oil outlet groove 33 is plural and is spaced along the circumferential direction of the first end plate 3, the first oil outlet groove 33 extends along the radial direction of the first end plate 3, and similarly, the second oil outlet groove 43 is plural and is spaced along the circumferential direction of the second end plate 4, and the second oil outlet groove 43 extends along the radial direction of the second end plate 4. It should be noted that the number of the first communicating grooves 31 and the number of the first oil outlet grooves 33 may be different, and the number of the first oil outlet grooves 33 and the number of the second oil outlet grooves 43 may be different.

In some embodiments, the number of the first header oil outlet holes 34 is N1, the first header oil outlet holes 34 are evenly arranged along the circumference of the first header 3, the number of the second header oil outlet holes 44 is N2, and the second header oil outlet holes 44 are evenly arranged along the circumference of the second header 4, where N1 < N2.

It should be noted that, when the rotor assembly according to the embodiment of the present invention is installed in the stator, the second end plate corresponds to the outlet end of the stator winding, that is, the outlet end of the stator winding extends out of the casing of the motor from the second end plate side, and the outlet end of the stator winding has the outlet wire and is higher than the non-outlet end of the stator winding, so that the heat generation amount is large. Of course, if the outgoing lines of the stator winding extend out of the casing of the motor from the first end plate side, the number of the first end plate oil outlet holes is set to be greater than that of the second end plate oil outlet holes correspondingly.

In addition, the number of the first-end plate oil outlet holes 34 and the number of the second-end plate oil outlet holes 43 may be different. Preferably, the number of first end plate oil outlet holes 34 is less than the number of second end plate oil outlet holes 43. Therefore, the balanced cooling of the two ends of the stator winding can be better realized.

Alternatively, the first-end-plate oil outlet holes 34 have a smaller diameter than the second-end-plate oil outlet holes 43. Therefore, the balanced cooling of the two ends of the stator winding can be better realized.

In some embodiments, the number of the oil outlet holes 34 of the first end plate 3 is two, the number of the oil outlet holes 44 of the second end plate is four, the oil outlet holes 34 of the first end plate are oppositely arranged along the radial direction of the first end plate 3, and the oil outlet holes 44 of the second end plate are uniformly arranged along the circumferential direction of the second end plate 4.

As shown in fig. 7 and 9, the number of the first oil outlet grooves 33 and the number of the second oil outlet grooves 43 are four, two first end plate oil outlet holes 34 are formed in two opposite first oil outlet grooves 33, and four second end plate oil outlet holes 44 are formed in four second oil outlet grooves 43, so that it can be better ensured that part of the cooling oil can enter the rotor oil passage 11 through the first oil grooves and then be ejected through the second end plate oil outlet holes 44.

In some embodiments, the opening direction of the outlet end of the first end plate oil outlet hole 34 and the opening direction of the outlet end of the second end plate oil outlet hole 44 are both directed toward the stator winding. In other words, the opening direction of the outlet ends of the first end plate oil outlet holes 34 faces outward in the radial direction of the first end plate. In other embodiments, the outlet ends of the second end plate oil outlet holes 44 are opened in a direction radially outward of the second end plate. Therefore, the cooling oil can be better directly sprayed to the end part of the stator winding on the periphery of the rotor core 1, and the cooling efficiency is improved.

As shown in fig. 11, in some embodiments, the outer circumferential wall of the stator core 5 is provided with stator grooves 52 and/or cut edges 53 extending in the axial direction to the stator core 5, the stator grooves 52 and the cut edges 53 are distributed at intervals along the circumferential direction of the stator core 5, and a space between the stator grooves 52 and/or the cut edges 53 and the inner circumferential wall of the housing 8 is a cooling oil passage 51. In other words, the outer peripheral wall of the stator core 5 may be provided with only the stator groove 52, only the cut edge 53, or both the stator groove 52 and the cut edge 53.

The stator groove 52 is formed to effectively increase the contact area between the cooling oil and the stator core 5, so that the cooling oil can more sufficiently contact the stator core 5, thereby reducing the thermal contact resistance between the cooling liquid and the stator core 5, improving the heat dissipation efficiency of the stator core 5, and saving the raw material of the stator core 5. Set up side cut 53 on the one hand and can increase coolant flow channel volume, improve the cooling oil flow state, make it flow more fully even, flow energy loss reduces, and on the other hand makes coolant flow channel surface area reduce, reduces the runner flow resistance, improves cooling efficiency, and in addition, side cut 53 still further makes stator core 5's structure volume reduce, practices thrift raw and other materials, reduction in production cost.

As shown in fig. 12, in some embodiments, the outer peripheral wall of the stator core 5 is provided with stator circumferential grooves 54, the number of the stator circumferential grooves 54 is at least one, and the stator core 5 is divided into a grooved core segment and a non-grooved core segment in the axial direction thereof, and the number of the non-grooved core segments is at least two. It will be appreciated that the core segment in which the stator circumferential groove 54 is located is a grooved core segment and the other core segments are non-grooved core segments, with each grooved core segment being disposed between two non-grooved core segments. The stator circumferential groove 54 is arranged, so that materials can be saved, the raw material cost is effectively reduced, the contact area of the cooling liquid and the stator core 5 can be increased by the stator circumferential groove 54, and the heat dissipation efficiency of the stator core 5 is improved.

Further, be equipped with stator recess 52 and/or side cut 53 on the periphery wall of non-recess core section, combine together stator recess 52, side cut 53 and stator circumference recess 54 for stator core 5's volume reduces greatly, and cost reduction, and the area of contact of cooling oil and stator core 5 is bigger, and the radiating effect is better.

Specifically, the stator groove 52 is rectangular, and the depth of the stator groove 52 satisfies the relation:

where a is a depth of the stator groove 52, Rout is an outer diameter of the stator core 5, Rin is an inner diameter of the stator core 5, L is a yoke thickness of the stator core 5, h is a lamination thickness of the stator core 5, and k1 is a coefficient and is 0.05-0.1.

In order to further increase the contact area between the stator core 5 and the cooling liquid, the stator groove 52 is rectangular, so that both side surfaces and one bottom surface of the stator groove 52 can be in contact with the cooling liquid, and the cooling effect of the cooling liquid on the stator core 52 is effectively improved.

As shown in fig. 17, the inventor found through research that as the coefficient K1 is gradually increased, the pressure drop of the motor (i.e., the flow resistance of the cooling liquid) is increased, and the maximum temperature rise rate of the motor is decreased. The larger the pressure drop is, the higher the lift of an oil pump which is required to supply cooling liquid to the motor is, the lower the temperature rise of the motor corresponds to the thermal performance of the motor, the smaller the temperature rise is, the longer the service life and the better the performance of the motor are, after comprehensive consideration, the coefficient K1 is 0.05-0.1, the pressure drop of the motor is smaller in the value range, the maximum temperature rise rate of the motor is smaller, the thermal performance of the motor is good, and the heat dissipation effect of the stator groove 52 is better.

In some embodiments, the depth of the cut-edge 53 satisfies the relationship:

as shown in fig. 13 and 14, where b is the depth of the cut edge 53, Rout is the outer diameter of the stator core 5, Rin is the inner diameter of the stator core 5, L is the yoke thickness of the stator core 5, h is the lamination thickness of the stator core 5, and k2 is a coefficient and is 0.05-0.1.

As shown in fig. 18, the inventor has found through research that, as the coefficient K2 increases, the voltage drop (flow resistance of the cooling liquid) of the motor increases, and the maximum temperature rise rate of the motor decreases gradually, and the coefficient is selected to be 0.05-0.1 through comprehensive consideration, and the voltage drop of the motor is smaller in the value range, the maximum temperature rise of the motor is smaller, the thermal performance of the motor is good, the heat dissipation effect of the stator core 5 is better, raw materials can be saved, and the raw material cost is reduced by 5.3%.

As shown in fig. 15 and 16, in some embodiments, the number of the housing oil inlets 81 is multiple and distributed along the circumferential direction of the housing 8, an included angle α between central axes of adjacent housing oil inlets 81 is less than or equal to 180 degrees, and a central angle β between a projection of a center of the housing oil inlet 81 and a center of the cutting edge 53 nearest to the center on the cross section of the stator core 5 is 0 to 5 degrees.

It can be understood that the central angle β refers to a line connecting the center of the liquid inlet and the center of the stator core 5, and a line connecting the midpoint of the cut edge 53 closest to the liquid inlet and the center of the stator core 5, and an included angle between projections of two straight lines on the cross section of the stator core 5 is 0 to 5 degrees.

As shown in fig. 19, the horizontal axis of the graph is the angle of the central angle β, and the vertical axis is the voltage drop and the maximum temperature rise of the motor, and the inventor found through research that when the central angle β is gradually increased from 0 to 5 degrees, the speed of increasing the voltage drop and the maximum temperature rise of the motor is slow (the slopes of the two curves are small), and when the central angle β is gradually increased from 5 to 10 degrees, the speed of increasing the voltage drop and the maximum temperature rise of the motor of the cooling system is significantly increased (the slopes of the two curves are increased), the requirement for the oil pump lift is increased, the cost of the motor is increased, and the thermal performance of the motor is poor, so that the central angle between the center of the liquid inlet and the projection of the center of the trimming edge 53 nearest to the center of the liquid inlet on the cross section of the stator core 5 is set to 0 to 5 degrees.

A motor according to some specific examples of the invention is described below with reference to the accompanying drawings.

As shown in fig. 1, the motor according to the specific example of the present invention includes a housing 8, a first end cap 6, a second end cap 7, a stator, and a rotor.

The first end cover 6 is installed at the first end of the machine shell 8, a first oil injection ring 61 is arranged on the inner side surface of the first end cover 6, the second end cover 7 is installed at the second end of the machine shell 8, a second oil injection ring 71 is arranged on the inner side surface of the second end cover 7, an end cover oil inlet 72 is formed in the second end cover 7, the first oil injection ring 61 and the first end cover 6 are of an integrated structure, and the second oil injection ring 71 and the second end cover 7 are of an integrated structure.

The stator comprises a stator core 5 and a stator winding, a cooling oil channel 51 is formed between the outer peripheral wall of the stator core 5 and the inner peripheral wall of the shell 8, the shell 8 is further provided with a shell oil inlet 81 communicated with the cooling oil channel 51, the shell oil inlets 81 are distributed along the circumferential direction of the shell 8, the included angle between the central axes of the adjacent shell oil inlets 81 is less than or equal to 180 degrees, and the central angle between the center of the shell oil inlet 81 and the projection of the center of the trimming edge 53 nearest to the center on the cross section of the stator core 5 is 0-5 degrees.

As shown in fig. 5 and 6, an oil injection space communicated with the cooling oil passage 51 is formed between the outer peripheral walls of the first oil injection ring 61 and the second oil injection ring 71 and the inner peripheral wall of the casing 8, a plurality of first oil injection holes 611 are formed in the first oil injection ring 61, a plurality of second oil injection holes 711 are formed in the second oil injection ring 71, and the first oil injection holes 611 and the second oil injection holes 711 are both communicated with the oil injection space and used for injecting cooling oil from the outer periphery of the stator toward the first end and the second end of the stator winding, respectively.

The rotor includes rotor core 1, rotor magnet steel and pivot 2, is equipped with rotor oil circuit 11 in the rotor core 1, is equipped with pivot oil circuit 21 in the pivot 2, and the first end of pivot is equipped with pivot oil outlet 23, and the second end of pivot 2 is equipped with pivot oil inlet 22.

As shown in fig. 7-10, a first end of the rotor core 1 is provided with a first end plate 3, a second end of the rotor core 1 is provided with a second end plate 4, the first end plate 3 is provided with a first oil groove, the second end plate 4 is provided with a second oil groove, the first oil groove is communicated with the rotor oil outlet and the rotor oil path 11, and the second oil groove is communicated with the rotor oil path 11.

The first end plate 3 is provided with a first end plate oil outlet hole 34, the second end plate oil outlet hole 44 of the second end plate 4, the first end plate oil outlet hole 34 is communicated with the first oil groove, and the second end plate oil outlet hole 44 is communicated with the second oil groove.

The first oil groove comprises a first connecting groove 31, a first guide groove 32 and a first oil outlet groove 33, a first end of the first connecting groove 31 is communicated with the rotating shaft oil outlet hole 23, a second end of the first connecting groove 31 is communicated with the first guide groove 32, and the first guide groove 32 is communicated with the rotor oil path 11; the second oil groove includes a second guide groove 42 and a second oil outlet groove 43, and the second guide groove 42 communicates with the rotor oil passage 11. The cooling oil in the rotating shaft oil path 21 enters the first connecting groove 31 through the rotating shaft oil outlet 23, flows from the first end of the first connecting groove 31 to the second end, flows into the first guide groove 32 from the second end of the first connecting groove 31, enters the first end of the first oil outlet groove 33 through the first guide groove 32, is sprayed out through the second end of the first oil outlet groove 33 and the first end plate oil outlet 34, and the rest of the cooling oil enters the rotor oil path 11 through the first guide groove 32, flows to the second guide groove 42, flows into the first end of the second oil outlet groove 43 through the second guide groove 42, and is finally thrown out through the second end plate oil outlet 44.

First connecting groove 31 is four and follows the circumference interval arrangement of first end plate 3, and first connecting groove 31 is along the radial extension of first end plate 3, and first oil groove 33 is four and follows the circumference interval arrangement of first end plate 3, and first oil groove 33 is along the radial extension of first end plate 3, and the contained angle that two adjacent first connecting grooves 31 and two adjacent oil grooves go out is 90 degrees, and first connecting groove 31 and first oil groove 33 staggered arrangement.

The number of the first end plate oil outlet holes 34 is two, and the first end plate oil outlet holes are arranged along the radial direction of the first end plate 3 and are respectively communicated with the second ends of the two first oil outlet grooves 33. The second oil outlet grooves 43 are four and are arranged at intervals in the circumferential direction of the second end plate, and the second oil outlet grooves 43 extend in the radial direction of the second end plate 4. The included angle between two adjacent second oil outlet grooves 43 is 90 degrees. The number of the second end plate oil outlet holes 44 is four, the second end plate oil outlet holes are evenly arranged along the circumferential direction of the second end plate 4 and are respectively communicated with the four second oil outlet grooves 43, and the second end plate oil outlet holes 44 and the second oil outlet grooves 43 are in one-to-one correspondence.

The opening direction of the outlet end of the first end plate oil outlet hole 34 faces outwards along the radial direction of the first end plate, and the opening direction of the second end plate oil outlet hole 44 faces outwards along the radial direction of the second end plate, so that the thrown cooling oil can be directly sprayed to the first end and the second end of the stator winding positioned on the periphery of the rotor core 1, and the cooling effect is improved.

As shown in fig. 12, the circumferential wall of the stator core 5 is provided with a stator circumferential groove 54 extending along the circumferential direction of the stator core 5, the stator circumferential groove 54 divides the stator core 5 into a groove core segment and two non-groove core segments, and the stator groove 52 and the cut edge 53 extending along the axial direction of the stator core 5 are provided on the two non-groove core segments, thereby reducing the volume of the stator core 5 and improving the cooling efficiency.

The stator groove 52 is rectangular, and the depth of the stator groove 52 satisfies the relation:

the depth of the cut edge 53 satisfies the relation:

where a is a depth of the stator groove 52, where b is a depth of the cut edge 53, Rout is an outer diameter of the stator core 5, Rin is an inner diameter of the stator core 5, L is a yoke thickness of the stator core 5, h is a lamination thickness of the stator core 5, k1 is a coefficient and is 0.05-0.1, and k2 is a coefficient and is 0.05-0.1. This can improve the cooling effect.

According to the embodiment of the invention, the vehicle comprises the motor, the motor can be the motor of the embodiment, and the performance of the vehicle is improved by improving the heat dissipation efficiency of the motor. The vehicle may be a pure electric vehicle, and may also be a new energy vehicle in other forms, and of course, in the embodiment of the present invention, the vehicle is not limited thereto.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" and the like mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. An electric machine, comprising:

the oil inlet of the shell is arranged on the shell;

the stator comprises a stator core and a stator winding, the stator is arranged in an inner cavity of the shell, a cooling oil duct is formed between the outer peripheral wall of the stator core and the inner peripheral wall of the shell, and the cooling oil duct is communicated with the oil inlet of the shell;

the oil inlet of the first end cover is arranged at the first end of the shell, and the oil inlet of the second end cover is arranged at the second end of the shell;

the first oil injection ring is arranged on the inner side of the first end cover, an oil injection space communicated with the cooling oil duct is formed between the outer peripheral wall of the first oil injection ring and the inner peripheral wall of the shell, a plurality of first oil injection holes are formed in the first oil injection ring and are arranged at intervals in the circumferential direction of the first oil injection ring, and the first oil injection holes are communicated with the oil injection space and used for injecting cooling oil from the outer periphery of the stator towards the first end of the stator winding;

the rotor comprises a rotor core, rotor magnetic steel and a rotating shaft, a rotor oil path is arranged in the rotor core, a rotating shaft oil path is arranged in the rotating shaft, a rotating shaft oil inlet and a rotating shaft oil outlet which are communicated with the rotating shaft oil path are arranged on the rotating shaft, a first end of the rotating shaft penetrates through the first end cover to extend out of the shell, and the rotating shaft oil inlet is communicated with the end cover oil inlet;

the first end plate is arranged at the first end of the rotor core and matched with the rotating shaft, a first oil groove is arranged on the inner side surface of the first end plate opposite to the rotor core and is respectively communicated with the rotating shaft oil outlet and the rotor oil way, and a first end plate oil outlet for communicating the first oil groove with the inner cavity of the shell is arranged on the outer side surface of the first end plate;

the second end plate, the second end plate is established rotor core's second end and with the pivot cooperation, the second end plate with be equipped with the second oil groove on the medial surface that rotor core is relative, the second oil groove with rotor oil circuit intercommunication, the lateral surface of second end plate be equipped with be used for with the second oil groove with the second end plate oil outlet of the inner chamber intercommunication of casing.

2. The electric machine of claim 1, further comprising a second oil injection ring disposed inside the second end cover, wherein an oil injection space communicating with the cooling oil passage is formed between an outer peripheral wall of the second oil injection ring and an inner peripheral wall of the casing, and a plurality of second oil injection holes are disposed on the second oil injection ring at intervals in a circumferential direction of the second oil injection ring, and the second oil injection holes communicate with the oil injection space for injecting the cooling oil from an outer periphery of the stator toward the second end of the stator winding.

3. The electric machine of claim 2, wherein the first oil jet ring is removably mounted on or integrally formed with the first end cap and/or the second oil jet ring is removably mounted on or integrally formed with the second end cap.

4. The electric machine of claim 2, wherein the first oil jet has a circular cross-section, and of two adjacent first oil jets, the cross-sectional area of the higher first oil jet is greater than the cross-sectional area of the lower first oil jet; and/or the cross section of the second oil injection hole is circular, and the cross section area of the higher second oil injection hole is larger than that of the lower second oil injection hole in two adjacent second oil injection holes.

5. The electric machine of claim 2, wherein the first oil spray ring is divided into a first upper ring segment located above the center of the first oil spray ring and a first lower ring segment located below the center of the first oil spray ring, the cross-sectional area of the first oil spray hole in the first upper ring segment increases gradually in the radial direction of the first oil spray ring from the outside to the inside, and the cross-sectional area of the first oil spray hole in the first lower ring segment decreases gradually in the radial direction of the first oil spray ring from the outside to the inside; and/or the second oil injection ring is divided into a second upper ring section located above the center of the second oil injection ring and a second lower ring section located below the center of the second oil injection ring, the cross-sectional area of a second oil injection hole in the second upper ring section is gradually increased in the radial direction of the second oil injection ring along the direction from outside to inside, and the cross-sectional area of a second oil injection hole in the second lower ring section is gradually decreased in the radial direction of the second oil injection ring along the direction from outside to inside.

6. The electric machine of claim 1, wherein the first oil groove comprises a first communication groove, a first guide groove and a first oil outlet groove, a first end of the first communication groove is communicated with the rotating shaft oil outlet hole, a second end of the first communication groove is communicated with the first guide groove, a first end of the first oil outlet groove is communicated with the first guide groove, and a second end of the first oil outlet groove is communicated with the first end plate oil outlet hole;

the second oil groove comprises a second annular groove and a second oil outlet groove, the second annular groove is communicated with the rotor oil way, the first end of the second oil outlet groove is communicated with the second annular groove, and the second end of the second oil outlet groove is communicated with the second end plate oil outlet hole.

7. The electric machine of claim 6, wherein the first connecting slot is offset from the first oil outlet slot in a radial direction of the first end plate.

8. The electric machine of claim 6, wherein the first connecting grooves are plural and are spaced apart along a circumferential direction of the first end plate, the first connecting grooves extend along a radial direction of the first end plate, the first oil outlet grooves are plural and are spaced apart along the circumferential direction of the first end plate, and the first oil outlet grooves extend along the radial direction of the first end plate;

9. The electric machine according to claim 1, wherein the lead-out wires of the stator winding extend from the second end cover side, the number of the first end plate oil outlet holes is N1 and the first end plate oil outlet holes are evenly arranged in the circumferential direction of the first end plate, the number of the second end plate oil outlet holes is N2 and the second end plate oil outlet holes are evenly arranged in the circumferential direction of the second end plate, where N1 < N2.

10. The electric machine of claim 1 wherein the number of first end plate oil outlet holes is less than the number of second end plate oil outlet holes.

11. The electric machine of claim 1 wherein the first end plate oil outlet has a smaller bore diameter than the second end plate oil outlet.

12. The electric machine of claim 1, wherein the opening direction of the outlet end of the first end plate oil outlet hole and the opening direction of the outlet end of the second end plate oil outlet hole are both directed toward the stator winding.

13. The electric machine according to any one of claims 1-11, characterized in that the peripheral wall of the stator core is provided with stator grooves and/or cut edges extending in the axial direction of the stator core, the cooling oil channels being formed by the stator grooves and/or the cut edges.

14. The electric machine according to claim 13, wherein the outer peripheral wall of the stator core is provided with at least one stator circumferential groove extending in the circumferential direction of the stator core so that the stator core is divided in the axial direction thereof into a plurality of non-recessed core segments and at least one recessed core segment, and the outer peripheral wall of the non-recessed core segments is provided with stator grooves and/or cut edges extending in the axial direction of the stator core and spaced apart in the circumferential direction of the stator core.

15. The electric machine of claim 13, wherein the stator grooves are rectangular and the depth of the stator grooves satisfies the relationship:

wherein a is the depth of the stator groove, R_outIs the outer diameter of the stator, R_inIs the inner diameter of the stator, L is the yoke thickness of the stator, h is the lamination thickness of the stator, and k1 is a coefficient and is 0.05-0.1.

16. The electric machine of claim 13, wherein the depth of the cutting edge satisfies the relationship

Wherein b is the depth of the cut edge, R_outIs the outer diameter of the stator, R_inIs the inner diameter of the stator, L is the yoke thickness of the stator, h is the lamination thickness of the stator, and k1 is a coefficient and is 0.05-0.1.

17. The electric machine of claim 13, wherein the plurality of the housing oil inlets are distributed along the circumferential direction of the electric machine housing, the included angle α between the central axes of the adjacent housing oil inlets is less than or equal to 180 degrees, and the central angle β between the center of the housing oil inlet and the projection of the center of the nearest cutting edge thereof on the cross section of the stator core is 0-5 degrees.

18. A vehicle, characterized by comprising an electric machine according to any one of claims 1-17.