CN112436654A

CN112436654A - Motor casing and motor with cooling function

Info

Publication number: CN112436654A
Application number: CN202011162680.9A
Authority: CN
Inventors: 欧阳鹏; 刘磊
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2020-10-27
Filing date: 2020-10-27
Publication date: 2021-03-02

Abstract

The invention provides a motor housing with a cooling function and a motor. The motor comprises a stator core (30) and a stator winding (40) which are used for accommodating a motor in a shell, wherein the motor shell comprises an outer shell (10) and an inner shell (20) which are cylindrical, the outer shell (10) is sleeved on the periphery of the inner shell (20), a first flow channel (C1) for enabling a coolant to pass through is formed between the outer shell (10) and the inner shell (20), at least one liquid inlet (11) which is opened to the first flow channel (C1) is formed in the peripheral wall of the outer shell (10), a plurality of liquid outlets (21) which are opened to the first flow channel (C1) are formed in the peripheral wall of the inner shell (20), and the area where the liquid outlets (21) are located coincides with the areas where the stator core (30) and the stator winding (40) are located in the axial direction (A) of the inner shell (20). The motor shell has a simple structure and can provide a reasonable coolant conveying flow channel for the motor stator.

Description

Motor casing and motor with cooling function

Technical Field

The present invention relates to the field of electric machines, and in particular to a motor housing and an electric machine with a cooling function.

Background

Electric machines, including electric motors and engines, such as those found in electric axle (emaxle) drive systems for electric-only vehicles or hybrid electric-hybrid vehicles, tend to generate significant heat during operation.

One possible method for dissipating heat from the electric machine is to flow a coolant, for example oil, through heat-generating components of the electric machine.

For example, for a stator assembly of an electric machine, which includes a stator core and stator windings wound around the stator core and protruding from both axial ends of the stator core, one possible heat dissipation method is to provide a guide plate with a coolant channel at the outer periphery of an end of the stator assembly, and the coolant can flow out of the channel and flow to the stator windings located at both axial sides of the stator core; another possible heat dissipation method is to provide a duct for flowing a coolant at the outer periphery of the stator assembly, and the coolant can flow out of the opening of the duct and flow to the stator windings located at both axial sides of the stator core and the outer surface of the end portion of the stator core.

However, the above cooling structure has a limited cooling area for the stator assembly, and needs to provide a flow path for the coolant, such as a guide plate or a duct, and the system structure is complicated and costly.

Disclosure of Invention

It is an object of the present invention to overcome or at least alleviate the above-mentioned deficiencies of the prior art and to provide a motor housing and a motor having a cooling function.

According to a first aspect of the present invention, there is provided a motor housing having a cooling function, the housing accommodating therein a stator core and a stator winding of a motor, wherein the motor housing includes an outer housing and an inner housing each having a cylindrical shape, the outer housing being fitted over an outer periphery of the inner housing, a first flow passage for passing a coolant being formed between the outer housing and the inner housing,

the peripheral wall of the housing is formed with at least one liquid inlet opening which opens to the first flow passage,

the peripheral wall of the inner shell is provided with a plurality of liquid outlets which are opened towards the first flow passage, and the areas where the liquid outlets are located are overlapped with the areas where the stator core and the stator winding are located in the axial direction of the inner shell.

In at least one embodiment, in the axial direction, there are at least three liquid outlets, and the three liquid outlets are respectively located in an area where the stator windings protruding from two end portions of the stator core are located and an area where the stator core is located.

In at least one embodiment, the liquid outlet ports are distributed in a plurality of regions in the circumferential direction of the inner housing.

In at least one embodiment, the first flow passage is formed by an outer peripheral wall of the inner housing being partially recessed radially inward.

In at least one embodiment, the first flow passage wraps around the outer peripheral wall of the inner housing in a zigzag manner.

In at least one embodiment, a sealing means is provided between the outer housing and the inner housing for preventing the coolant from flowing out of the first flow passage from apertures other than the liquid outlet.

According to a second aspect of the present invention, there is provided an electric motor including a motor housing, and a stator core and a stator winding accommodated in the motor housing, the stator winding protruding from the stator core at both axial ends thereof, wherein the motor housing is the motor housing having a cooling function according to the present invention.

In at least one embodiment, the stator core and the inner shell are embedded in the inner shell in an interference fit manner, a second flow channel is formed between the stator core and the inner shell, and the second flow channel is communicated with the liquid outlet.

In at least one embodiment, the second flow channel is open to both axial ends of the stator core, so that the coolant can flow to the stator winding via the second flow channel.

In at least one embodiment, the second flow passage is formed by an outer peripheral wall of the stator core being partially recessed radially inward.

The motor shell has a simple structure and can provide a reasonable coolant conveying flow channel for the motor stator.

The motor has good cooling effect.

Drawings

Fig. 1 is a schematic view of a partial structure of a motor according to an embodiment of the present invention.

Fig. 2 is a schematic view of the motor of fig. 1 with the housing removed.

Fig. 3 is a schematic view of a stator assembly of an electric machine according to an embodiment of the present invention.

Fig. 4 is a schematic view of the half section of fig. 1.

Fig. 5 is a schematic view of fig. 1 viewed in the axial direction.

Description of reference numerals:

10a housing; 11 a housing liquid inlet; 10a groove;

20 an inner shell; 21 an inner shell liquid outlet;

a first flow path C1; a second flow path C2;

30 stator cores; 40 stator windings;

axial direction A; r is radial.

Detailed Description

Exemplary embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the detailed description is intended only to teach one skilled in the art how to practice the invention, and is not intended to be exhaustive or to limit the scope of the invention.

A motor housing and a motor having a cooling function according to the present invention will be described with reference to fig. 1 to 5. With reference to fig. 1 and 4, unless otherwise specified, a indicates the axial direction of the machine, which coincides with the axial direction of the casing 10 of the machine; r denotes the radial direction of the machine, which corresponds to the radial direction of the housing 10 of the machine.

Referring to fig. 1 and 4, the motor according to the present invention includes a housing and a stator assembly fixed to an inner circumferential side of the housing.

The housing comprises an outer shell 10 and an inner shell 20 which are nested with each other and are both cylindrical. The outer shell 10 and the inner shell 20 are sleeved on the outer periphery of the inner shell 20 in an interference fit manner.

Preferably, referring to fig. 4, an outer peripheral wall of one axial end portion of the inner housing 20 partially protrudes radially outward to form an inner housing flange portion 20f, a main body of the inner housing 20 is fitted to an inner periphery of the outer housing 10, and the inner housing flange portion 20f abuts against an axial end face of the outer housing 10. Preferably, the end of the outer casing 10 cooperating with the inner casing flange portion 20f is partially recessed radially outwardly to form an annular groove 10a, the inner casing flange portion 20f being at least partially received in the groove 10 a.

The stator assembly includes a stator core 30 and a stator winding 40 wound around the stator core 30. Both ends of the stator winding 40 in the axial direction a extend beyond the stator core 30. The inner circumferential side of the stator assembly is used to house a rotor (not shown).

Referring to fig. 2 and 4, a first flow passage C1 for circulating a coolant (e.g., oil) is formed between the outer case 10 and the inner case 20.

In the present embodiment, the inner peripheral wall of the outer casing 10 on the outer peripheral side of the first flow passage C1 is a smooth cylindrical surface, and the first flow passage C1 is formed by partially recessing the outer peripheral wall of the inner casing 20 radially inward.

It should be understood that in other possible embodiments, the inner circumferential wall of the casing 10 may also be partially recessed radially outward to form at least a portion of the first flow passage C1.

In the present embodiment, the first flow passage C1 surrounds the inner shell 20 in a cylindrical spiral shape. And in the axial direction a, the first flow channel C1 completely covers the area where the stator core 30 is located, and the first flow channel C1 extends beyond the stator core 30 at both axial ends to the area where the stator windings 40 at both axial ends are located.

It should be understood that, in other possible embodiments, the first flow channel C1 may have other meandering shapes to cover the above-mentioned stator core 30 and the areas where the stator windings 40 at both ends are located. For example, the path defined by the first flow path C1 is formed in a plurality of U shapes connected end to end, the straight part of the U shape extending in the axial direction a, and the turning part of the U shape being located at both end parts of the inner case 20. For another example, the path defined by the first flow channel C1 is formed as a plurality of parallel C-shaped sections extending in the circumferential direction of the inner shell 20 and bent sections connecting adjacent C-shaped sections. The present invention is not limited to the particular orientation of the first flow path C1, and it may also have other serpentine orientations, or include multiple parallel segments, for example.

The inlet of the first flow channel C1 is located in the outer shell 10 and the outlet is located in the inner shell 20.

Referring to fig. 1, the housing 10 has at least one opening, i.e., a liquid inlet 11, in a circumferential wall thereof. The liquid inlet 11 communicates with the first flow path C1. Preferably, there is only one liquid inlet 11, and the liquid inlet 11 is located at one end of the first flow passage C1 in the axial direction a.

Referring to fig. 2 and 5, the inner casing 20 has a plurality of openings, i.e., liquid outlets 21, on the circumferential wall thereof. The liquid outlet 21 communicates with the first flow passage C1. Preferably, the discharge openings 21 have three rows, and the discharge openings 21 of each row are staggered in the axial direction a, so that there are at least three discharge openings 21 in the axial direction a. Preferably, each row of liquid outlets 21 includes a plurality (8 in the present embodiment) of liquid outlets 21 distributed in the circumferential direction.

Preferably, the three liquid outlets 21 in the axial direction a are respectively located in the region where the stator core 30 is located and in the regions where the stator windings 40 at both ends of the stator core 30 in the axial direction, so that the coolant flowing out of the three liquid outlets 21 can be distributed to flow to the stator core 30 and the stator windings 40 at both ends to cool the stator assembly.

It should be understood that although in the embodiment shown in fig. 1, three rows of liquid outlet ports 21 spaced in the axial direction a are aligned in the circumferential direction of the inner casing 20, this is not essential, i.e., liquid outlet ports 21 located at different positions in the axial direction a may be circumferentially staggered.

It should be understood that in other possible embodiments, there may be more than three outlet orifices 21 in the axial direction a.

Referring to fig. 3 and 4, a second flow path C2 is further formed between the stator core 30 and the inner case 20, and the second flow path C2 communicates with a part of the liquid outlet ports 21 (e.g., a row of the liquid outlet ports 21 located at the axial middle portion in this embodiment). The second flow passage C2 also penetrates the stator core 30 in the axial direction a and is open to both axial end portions of the stator core 30, so that the coolant flowing out from the liquid outlet 21 can flow into the second flow passage C2 to radiate heat to the stator core 30, and the coolant can flow out from the outlets at both ends of the second flow passage C2 out of the second flow passage C2 to the stator windings 40 at both ends of the stator core 30 to continue radiating heat to the stator windings 40. The direction of flow of the coolant in the second flow passage C2 is indicated by hollow arrows in fig. 3.

Preferably, the inner circumferential wall of the inner case 20 on the outer circumferential side of the second flow passage C2 is a smooth cylindrical surface, and the second flow passage C2 is formed by partially recessing the outer circumferential wall of the stator core 30 radially inward. In the present embodiment, the second flow path C2 is plural in the circumferential direction, each second flow path C2 communicates with one liquid outlet 21 at the axial middle portion, and each second flow path C2 extends in the axial direction a.

It should be appreciated that, in other possible embodiments, the inner circumferential wall of the inner casing 20 may also be partially recessed radially outward to form at least a portion of the second flow passage C2.

It should be understood that the second flow passages C2 may also be curved or overlap each other.

Preferably, a sealing device is provided between the outer casing 10 and the inner casing 20, for example, a sealing ring is provided at each of both ends in the axial direction a of the inner casing 20, so as to prevent the coolant from leaking out of the first flow passage C1 from other apertures than the liquid outlet 21.

Next, the entire flow path of the coolant is described. The coolant flows into the first flow path C1 from the liquid inlet 11 of the outer casing 10, and flows out from the liquid outlet 21 of the inner casing 20 while traversing the outer periphery of the inner casing 20 in a zigzag winding along the first flow path C1. Wherein the coolant flowing out from the liquid outlet 21 located at the axial middle portion flows into the second flow passage C2, and the coolant flows along the second flow passage C2 to cool the stator core 30, and then flows out from the outlets of the second flow passages C2 located at the axial both ends of the stator core 30 and flows to the stator windings 40 located at the both ends of the stator core 30 to cool the stator windings 40; in addition, the coolant flowing out from the liquid outlets 21 at both ends in the axial direction directly flows to the stator windings 40 at both ends of the stator core 30 to cool the stator windings 40.

The invention has at least one of the following advantages:

(i) the motor shell has a cooling function, the coolant flow path provided by the motor shell is supported by the holes and the channels formed in the shell, an additional pipeline does not need to be arranged, the structure of the shell is simple, the number of parts is small, and the motor shell is convenient to manufacture.

(ii) The coolant flow path provided by the motor housing can be used to simultaneously deliver coolant to the stator core 30 and the stator windings 40 at both axial ends of the stator core 30, thereby reducing the temperature of the stator core 30 and the stator windings 40. Because the temperature rise of the motor is effectively controlled, an insulation system of the motor is not easy to work beyond the limit working temperature, the working performance of the motor is good, and the power supply is sufficient and stable.

(iii) Since the cooling effect of the motor is good, the axial dimension of the active working portion of the motor (including the stator core 30 and the stator windings 40) can be reduced, so that the motor has a compact size suitable for arrangement in, for example, a vehicle, and the cost can be reduced.

Of course, the present invention is not limited to the above-described embodiments, and those skilled in the art can make various modifications to the above-described embodiments of the present invention without departing from the scope of the present invention under the teaching of the present invention.

Claims

1. A motor housing with a cooling function, which is used for accommodating a stator core (30) and a stator winding (40) of a motor, is characterized in that the motor housing comprises an outer shell (10) and an inner shell (20) which are cylindrical, the outer shell (10) is sleeved on the periphery of the inner shell (20), a first flow passage (C1) for enabling a coolant to pass is formed between the outer shell (10) and the inner shell (20),

at least one liquid inlet (11) opening to the first flow path (C1) is formed in the peripheral wall of the housing (10),

the peripheral wall of the inner shell (20) is provided with a plurality of liquid outlets (21) which are opened towards the first flow channel (C1), and the areas of the liquid outlets (21) are overlapped with the areas of the stator core (30) and the stator winding (40) in the axial direction (A) of the inner shell (20).

2. The motor housing with a cooling function according to claim 1, wherein there are at least three liquid outlets (21) in the axial direction (a), and the three liquid outlets (21) are located in a region where the stator winding (40) protruding from both ends of the stator core (30) is located and a region where the stator core (30) is located, respectively.

3. The motor casing with a cooling function according to claim 1, wherein the liquid outlet (21) is distributed in a plurality of areas in a circumferential direction of the inner casing (20).

4. The motor casing with a cooling function according to claim 1, wherein the first flow passage (C1) is formed by a peripheral wall of the inner casing (20) being partially recessed radially inward.

5. The motor housing with a cooling function according to claim 1, wherein the first flow passage (C1) wraps the outer peripheral wall of the inner housing (20) in a zigzag manner.

6. The motor housing with a cooling function according to any one of claims 1 to 5, wherein a sealing means for preventing the coolant from flowing out of the first flow passage (C1) from an aperture other than the liquid outlet (21) is provided between the outer housing (10) and the inner housing (20).

7. An electric machine including a machine housing, and a stator core (30) and stator windings (40) accommodated in the machine housing, the stator windings (40) protruding the stator core (30) at both axial ends of the stator core (30), characterized in that the machine housing is a machine housing having a cooling function according to any one of claims 1 to 6.

8. The electric machine according to claim 7, wherein the stator core (30) is embedded in the inner housing (20) in an interference fit manner with the inner housing (20), a second flow channel (C2) is formed between the stator core (30) and the inner housing (20), and the second flow channel (C2) is communicated with the liquid outlet (21).

9. The electric machine according to claim 8, characterized in that the second flow channel (C2) is open to both axial ends of the stator core (30) such that the coolant can flow to the stator windings (40) via the second flow channel (C2).

10. The motor according to claim 8, wherein the second flow passage (C2) is formed by an outer peripheral wall of the stator core (30) being partially recessed radially inward.