CN118100482A

CN118100482A - Cooling system of motor, generator and hybrid electric vehicle

Info

Publication number: CN118100482A
Application number: CN202211446040.XA
Authority: CN
Inventors: 仇杰; 吴国良; 龚苏生; 陆欢; 冀田
Original assignee: SAIC Motor Corp Ltd
Current assignee: SAIC Motor Corp Ltd
Priority date: 2022-11-18
Filing date: 2022-11-18
Publication date: 2024-05-28

Abstract

The application discloses a cooling system of a motor, a generator and a hybrid electric vehicle, wherein the cooling system comprises a stator shell and a stator assembly positioned at the inner side of the stator shell, the stator assembly comprises a stator winding and a stator framework used for winding the stator winding, one end of the stator shell is provided with an annular end cover, and the stator framework, the stator shell and the end cover are enclosed to form an annular cooling cavity; the annular cooling cavity is provided with an oil inlet. The annular cooling cavity of the cooling system of the motor is provided with the oil inlet, and cooling oil can be supplied to the annular cooling cavity through the oil inlet. Because the end cover is matched with the stator framework and the stator shell, the annular cooling cavity is arranged, and cooling oil can flow in the annular cooling cavity after entering, so that the cooling oil is fully infiltrated into the stator winding of the stator assembly relatively, and a good heat dissipation effect is achieved.

Description

Cooling system of motor, generator and hybrid electric vehicle

Technical Field

The invention relates to the technical field of motors, in particular to a cooling system of a motor, a generator and a hybrid electric vehicle.

Background

The motor comprises a stator assembly and a rotor assembly, wherein the stator assembly comprises a stator shell and a stator assembly arranged on the inner side of the stator shell, the stator assembly comprises a stator core and a stator winding wound on the stator core, and the stator winding is positioned at the axial end part of the stator core to form an end winding extending out of the end part of the stator core.

Along with the higher and higher integration level of the motor for the vehicle, the motor is required to have the characteristics of high efficiency, wide rotating speed range, small volume, light weight, high power density, low cost and the like, wherein the power density of the motor is increased from 5.7kW/L to 50kW/L, and the motor has great challenges on the cooling and heat dissipation performance of the motor.

At present, the conventional cooling mode of the motor for the vehicle is water cooling or oil cooling. In the water-cooled motor, the cooling liquid has no insulativity, cannot be in direct contact with a heating component of the motor, and can only indirectly cool a stator assembly of the motor through the water jacket, but the cooling efficiency is generally not suitable for the motor with high power density. In the oil-cooled motor, cooling oil is directly sprayed to the end winding through the oil spray pipe, but the windings in the slots of the stator core can only indirectly dissipate heat outwards, and meanwhile, the end winding can be unevenly cooled due to the arrangement of the oil spray pipe.

Disclosure of Invention

The application provides a cooling system of a motor, which comprises a stator shell and a stator assembly positioned at the inner side of the stator shell, wherein the stator assembly comprises a stator winding and a stator framework used for winding the stator winding, one end of the stator shell is provided with an annular end cover, and the stator framework, the stator shell and the end cover are enclosed to form an annular cooling cavity; the annular cooling cavity is provided with an oil inlet.

In one embodiment, the oil inlet is disposed at an end of the annular cooling cavity proximate the end cap.

In a specific embodiment, the annular cooling cavity comprises two oil inlets, which are both arranged on the stator housing; the two oil inlets are symmetrically arranged in the radial direction or the axial direction of the annular cooling cavity is horizontal, and the two oil inlets are arranged at the top of the stator housing.

In a specific embodiment, a communication port is formed in the radial inner side of the stator framework at the other end opposite to the oil inlet, and the communication port is communicated with a rotor assembly of the motor.

In one specific embodiment, the stator assembly comprises a plurality of stator units distributed along the circumferential direction, each stator unit comprises a stator single tooth, an insulating framework wrapped on the tooth part of the stator single tooth, and a single-tooth winding wound on the insulating framework, the plurality of insulating frameworks are spliced along the circumferential direction to form the stator framework, and the side edges of the radial inner sides of adjacent insulating frameworks are abutted;

A notch is formed in one axial end of the insulating framework, and the notches adjacent to the insulating framework are spliced to form the communication port; or, the insulating framework is provided with a notch or a through hole, and the notch or the through hole forms the communication port.

In a specific embodiment, the cooling device further comprises an oil pipe communicated with the oil inlet of the annular cooling cavity, the oil pipe is provided with a first oil hole and a second oil hole, the first oil hole is communicated with the oil inlet, and the second oil hole sprays cooling oil to the outer surface of the stator housing.

In a specific embodiment, the stator assembly comprises a plurality of stator units distributed along the circumferential direction, each stator unit comprises a stator single tooth, an insulating framework wrapped on the tooth part of the stator single tooth, and a single-tooth winding wound on the insulating framework, the plurality of insulating frameworks are spliced along the circumferential direction to form the stator framework, and the radially inner side edges of adjacent insulating frameworks are abutted.

In a specific embodiment, the end cover is a collecting ring, and the collecting ring is electrically connected with a plurality of the single-tooth windings at the same time.

The application also provides a generator, comprising the cooling system of the motor.

The application also provides a hybrid electric vehicle, which comprises the generator.

The annular cooling cavity of the cooling system of the motor is provided with the oil inlet, and cooling oil can be supplied to the annular cooling cavity through the oil inlet. Because the end cover is matched with the stator framework and the stator shell, the annular cooling cavity is arranged, cooling oil can flow in the annular cooling cavity after entering, and flows from one side to the other side through the oil duct formed by gaps among the windings, so that the cooling oil can be fully infiltrated into the stator windings of the stator assembly relatively, and a good heat dissipation effect is achieved.

Drawings

FIG. 1 is a schematic diagram of an electric motor in an embodiment of the application;

FIG. 2 is a schematic illustration of a stator assembly of the motor of FIG. 1;

FIG. 3 is an assembled schematic view of the stator assembly of FIG. 1;

FIG. 4 is a schematic illustration of a stator single tooth of the stator assembly of FIG. 3;

FIG. 5 is a schematic illustration of the assembly of the stator single tooth and insulating skeleton of FIG. 4;

FIG. 6 is a schematic view of a stator unit formed by winding the single tooth winding around the insulating skeleton of FIG. 5;

FIG. 7 is a partial view of adjacent two stator unit locations of FIG. 2;

FIG. 8 is a radial cross-sectional view of the motor of FIG. 1;

FIG. 9 is an enlarged view of a portion of the stator assembly of FIG. 8;

fig. 10 is a partial view of adjacent two stator unit locations at the second end of the stator assembly of fig. 2.

The reference numerals in fig. 1-10 are as follows:

1-a stator assembly;

11-a stator assembly; 111-stator single teeth; 1111-peripheral portion; 1112-teeth; 112-an insulating framework; 112 a-notch; 112 b-notch; 1121-U-shaped portion; 1122-a bottom plate; 1123-a top plate; 113-single tooth winding; 11 a-a communication port;

12-a stator housing; 12 a-a first oil inlet; 12 b-a second oil inlet;

13-end caps;

2-a rotor assembly;

31-a hub; 32-a shaft body;

41-a second oil pipe; 42-a third oil pipe; 43-arc connecting oil pipe; 44-a first oil pipe; 45-fourth oil pipe; 4 a-second oil hole.

Detailed Description

In order to better understand the aspects of the present invention, the present invention will be described in further detail with reference to the accompanying drawings and detailed description.

Referring to fig. 1-6, fig. 1 is a schematic diagram of an electric motor according to an embodiment of the application; fig. 2 is a schematic view of the stator assembly 1 of the motor of fig. 1; FIG. 3 is an assembled schematic view of the stator assembly 11 of FIG. 1; fig. 4 is a schematic view of stator single teeth 111 of stator assembly 11 of fig. 3; FIG. 5 is a schematic view of the assembly of the stator single teeth 111 and the insulating skeleton 112 of FIG. 4; fig. 6 is a schematic view of the stator unit 11 formed by winding the single-tooth winding 113 around the insulating bobbin 112 in fig. 5.

The motor in this embodiment comprises a stator assembly 1 shown in fig. 2, the stator assembly 1 comprises an annular stator housing 12 and a stator assembly positioned inside the stator housing 12, the stator assembly comprises a stator winding and a stator framework for winding the stator winding, and in particular in this embodiment, the stator assembly comprises a plurality of stator units 11 shown in fig. 6, and the plurality of stator units 11 are arranged in an annular shape and can be press-fitted into the stator housing 12 in an interference manner.

The "axial direction", "radial direction", and "circumferential direction" described in this embodiment are respectively the same as the axial direction, radial direction, and circumferential direction of the motor with reference to the motor.

As shown in fig. 3, each stator unit 11 includes a stator single tooth 111, an insulating skeleton 112 and a single tooth winding 113, the stator single tooth 111 is formed by stacking a plurality of punched sheets along the axial direction, and is of a generally T-shaped structure, including a peripheral portion 1111 fixed on the inner surface of the housing and a tooth portion 1112 protruding radially from the peripheral portion 1111, the plurality of peripheral portions 1111 are distributed along the circumferential direction, the insulating skeleton 112 is wrapped around the tooth portion 1112 of the stator single tooth 111, as shown in fig. 5, the insulating skeleton 112 includes two parts, the two parts are wrapped around the tooth portion 1112 of the stator single tooth 111 in an abutting manner along the axial direction, each part includes a U-shaped portion 1121 wrapped around the peripheral portion of the tooth portion 1112 and a bottom plate 1122 wrapped around the bottom portion of the tooth portion 1112, the bottom plate 1122 protrudes from the U-shaped portion 1121, so that a groove structure is formed between the bottom plate 1122 and the peripheral portion of the stator single tooth 111, the single tooth winding 113 can be wound around the groove structure, each part of the insulating skeleton 112 further includes a top plate 1123 opposite to the bottom plate 1122, the top plate 1123 extends from the peripheral portion 1111 of the stator single tooth 111 along the axial direction, the top plate 1123 is provided with a notch 1111, and the single tooth 113 can be threaded from the end of the single tooth 112.

With continued reference to fig. 2, the plurality of stator units 11 are circumferentially spliced into a circular stator assembly, specifically 24 stator units 11 in this embodiment, the plurality of single-tooth windings 113 form stator windings of the stator assembly, and the plurality of insulating bobbins 112 are circumferentially spliced to form stator bobbins of the stator assembly, wherein adjacent insulating bobbins 112 are located radially inward and are abutted against each other along axially extending side 1122a, that is, a bottom plate 11221122 of the insulating bobbins 112 shown in fig. 5 is abutted against each other along the axially extending side 1122a and the side 1122a of the adjacent insulating bobbins 112.

It can be understood in connection with fig. 7 that fig. 7 is a partial view of the positions of two adjacent stator units 11 in fig. 2.

In fig. 7, the side 1122a of the adjacent insulating bobbins 112 abut, and as shown in position C of fig. 7, the two side 1122a abut at position C, so that the inner side surfaces of the stator bobbins are relatively closed annular surfaces after the plurality of insulating bobbins 112 are sequentially spliced in the circumferential direction.

With continued reference to fig. 1, one end of the stator housing 12 along the axial direction is provided with an annular end cover 13, which can define one end of the end cover 13 as a first end, the other end of the end cover 13 opposite to the first end along the axial direction as a second end, and the two axial ends of the rest components respectively define the first end and the second end based on the first end and the second end, that is, the end, close to the end cover 13, of the end in the axial direction is the first end and the other end is the second end. The end cover 13 is sealed with the end face of the first end of the stator housing 12 and the end face of the first end of the stator framework, and at this time, the stator framework, the stator housing 12 and the end cover 13 are enclosed to form an annular cooling cavity.

In this embodiment, the cooling system of the motor further includes an oil pipe, and the annular cooling cavity is provided with an oil inlet, and the oil pipe is communicated with the oil inlet to provide cooling oil to the annular cooling cavity. So set up, owing to through setting up end cover 13 and designing insulating skeleton 112, can set up out annular cooling chamber, cooling oil can flow in annular cooling chamber after getting into to in the stator winding of stator module, the infiltration is fully reached relatively, reaches better radiating effect.

Specifically, as shown in fig. 1, the oil pipes include a second oil pipe 41 and a third oil pipe 42, which extend in the axial direction and are fitted to the outer surface of the stator housing 12. In addition, the oil pipes further comprise a first oil pipe 44 and a fourth oil pipe 45, the first oil pipe 44 and the fourth oil pipe 45 are communicated with the second oil pipe 41 and the third oil pipe 42 through three-section arc-shaped connecting oil pipes 43, the first oil pipe 44 and the fourth oil pipe 45 can be fixed on the gearbox shell through connecting pieces, cooling oil can be input from the end part of the first oil pipe 44, and oil is fed into the second oil pipe 41, the third oil pipe 42 and the fourth oil pipe 45 through the arc-shaped connecting oil pipes 43. The first oil pipe 44 and the fourth oil pipe 45 may be provided with third oil holes (not shown) which are provided for the same purpose as the second oil holes 4a and which are also provided toward the outer surface of the stator housing 12, so that the cooling oil may be injected toward the outer surface of the stator housing 12, thereby further improving the cooling effect.

In fig. 1, the oil inlet in this embodiment is disposed at a first end of the annular cooling cavity, the oil inlet may be disposed in the stator housing 12 or the end cover 13, two oil inlets, respectively, a first oil inlet 12a and a second oil inlet 12b, are illustrated in fig. 1, and are both located in the stator housing 12, and the oil inlets may radially penetrate through the stator housing 12 so as to communicate with the annular cooling cavity, the second oil pipe 41 is provided with a first oil hole (not shown in the drawing) and is communicated with the first oil inlet 12a, and the third oil pipe 42 is also provided with a first oil hole and is communicated with the second oil inlet 12b.

As shown in fig. 8 and 9, fig. 8 is a radial cross-sectional view of the motor of fig. 1; fig. 9 is an enlarged view of a portion of the stator assembly of fig. 8.

In this embodiment, the first end of the annular cooling cavity is provided with the end cover 13, the second end is open, then the whole second end can be used as the oil return port 1a, the oil inlet is arranged at the first end, the cooling oil can flow along the axial direction, in fig. 8, namely, move from left to right, and flow out from the second end, so that the cooling oil can flow through the stator winding fully along the axial direction, and heat dissipation is better. It can be seen that the second end can also be provided with a cover body and a corresponding oil return port, so that the flow direction of the cooling oil can be guided more flexibly according to the requirement, but the second end is opened, the oil return pressure is lower, and the smooth flow of the cooling oil is facilitated.

Referring again to fig. 1, the second oil pipe 41 and the third oil pipe 42 are provided with a first oil hole communicating with the oil inlet at an end portion near the first end of the stator housing 12, and the side peripheral walls of the second oil pipe 41 and the third oil pipe 42 are also provided with second oil holes 4a, the second oil holes 4a being provided toward the outer surface of the stator housing 12, so that the cooling oil can be injected toward the outer surface of the stator housing 12, thereby further improving the cooling effect. The cooling oil in the second oil hole 4a is used for cooling the inner surface of the stator housing 12, and assists in heat dissipation of the stator winding, and the cooling oil enters the annular cooling cavity as a main heat dissipation mode, at this time, the apertures of the first oil hole and the second oil hole 4a can be designed so that more cooling oil can enter the annular cooling cavity, for example, the flow of the second oil hole 4a occupies 1/3 of the flow of the cooling oil, and the flow of the first oil hole occupies 2/3 of the flow of the cooling oil, which can be other ratios of course.

In addition, in this embodiment, the motor is horizontally placed, that is, the axis of the motor is horizontal, at this time, the first oil inlet 12a and the second oil inlet 12b are located at the top of the stator housing 12, and under the action of gravity, the downward flow of the cooling oil is more facilitated, the flow of the cooling oil in the circumferential direction is promoted, and heat dissipation is better realized. It will be appreciated that it is possible to provide one oil inlet or a plurality of oil inlets in the circumferential direction, the layout of fig. 1 being simpler and a relatively uniform flow of cooling oil already being possible by means of gravity. Of course, when the motor is vertically placed, namely, the axis is vertical, two radially symmetrical oil inlets can be formed, so that oil can be uniformly fed.

As shown in fig. 1, the highest position at the top of the motor is a first position a, the lowest position at the bottom is a second position B, the second oil pipe 41 and the third oil pipe 42 are respectively arranged at two sides of the first position a, the first position a and the second position B are radially symmetrical, and as two relatively close oil inlets are arranged, the cooling oil flow paths between the two oil inlets are opposite, and most of the cooling oil entering from one oil inlet flows in a direction away from the other oil inlet. In fig. 1, most of the cooling oil in the first oil inlet 12a located at the left side flows in the counterclockwise direction to the second position B, and most of the cooling oil in the second oil inlet 12B located at the right side flows in the clockwise direction to the second position B, i.e., the cooling oil flows in the opposite direction by half a turn from the vicinity of the first position a, so that the flow of the cooling oil at the left and right sides is relatively uniform. Therefore, the oil return port of the annular cooling cavity is positioned at the second end in the circumferential direction, and the cooling oil mainly moves downwards under the action of gravity, so that the cooling oil mainly moves along the circumferential direction, flows out from the oil return port after filling the annular cooling cavity, and can achieve a better cooling effect on the premise of arranging fewer oil pipes. Of course, such flow paths are the primary flow tendencies thereof, and in fact, the circumferential and axial flows are concurrent during flow.

It should be noted that, the stator assembly of the electric machine described in this embodiment is composed of a plurality of stator units 11, the cable end of the single-tooth winding 113 of each stator unit 11 needs to be electrically connected to the outside, and the end cover 13 may be a collecting ring, which is electrically connected to the plurality of single-tooth windings 113 at the same time, that is, the collecting ring is used as an electrical connection component of the plurality of single-tooth windings 113, and may also serve as a component for covering the stator housing 12 and the stator frame to form an annular cooling cavity. However, it is understood that the cable ends of the single-tooth windings 113 may be soldered to the positions to be connected, and that no slip rings may be provided, that is, the end caps 13 may merely cover the annular cooling chambers.

In addition, in this embodiment, the stator winding of the stator assembly is a fractional slot concentrated winding, that is, the stator winding component is set to be a plurality of single-tooth windings 113, gaps exist between adjacent single-tooth windings 113, when cooling oil enters the annular cooling cavity, the cooling oil easily enters between adjacent single-tooth windings 113, and can also enter into each single-tooth winding 113, so that the cooling effect is better. Of course, the solution may also be applied to an integral stator assembly, i.e. the stator frame is integral, and at this time, the stator winding is denser, and the fluidity of the cooling oil after entering is inferior to that of the embodiment, i.e. the stator assembly structure of the plurality of stator units 11 in the embodiment has a better cooling effect after the annular cooling cavity is provided.

Further, in this embodiment, the second end of the stator frame is provided with a communication port 11a, where the communication port 11a may be connected to the rotor assembly 2 of the motor, and the communication port 11a is, for example, a radially extending channel. In this way, the cooling oil flows from the first end to the second end of the annular cooling chamber, and before exiting the oil return port 1a, part of the cooling oil can enter the rotor assembly 2 while participating in the heat dissipation of the rotor assembly 2.

With continued reference to fig. 2, 5, 6, and fig. 10, fig. 10 is a partial view of the position of two adjacent stator units 11 at the second end of the stator assembly 1 of fig. 2.

The second axial end of the adjacent insulating frameworks 112 is provided with a notch 112b, when the adjacent two insulating frameworks 112 are spliced along the circumferential direction, the side 1122a of the insulating frameworks 112 are butted, but due to the notch 112b, the two notches 112b are spliced together to form a communication port 11a shown in fig. 10, and the communication port can be led to the rotor assembly 2 of the motor along the radial direction. The rotor assembly 2 is located at the inner side of the stator assembly 1, in this embodiment, the rotor assembly 2 includes a rotor core and magnetic steel, the magnetic steel can be a V-shaped oblique pole, and the magnetic steel can be directly inserted into the rotor core and fixed by magnetic steel glue. It will be appreciated that only one side of the insulating skeleton 112 may be notched or through holes may be provided, as long as cooling oil can flow radially or substantially radially to the rotor assembly 2.

With continued reference to fig. 1 and 8, in this embodiment, a motor shaft of the motor includes a shaft body 32 and a shaft hub 31 disposed at an outer periphery of the shaft body 32, the rotor assembly 2 is sleeved on the shaft hub 31 in an interference manner, the shaft hub 31 is provided with a plurality of axial oil channels 31b and a plurality of radial oil channels 31a, the shaft body 32 is circumferentially distributed with a plurality of oil ports, the plurality of oil ports are communicated with the plurality of radial oil channels 31a in the shaft hub 31, the plurality of radial oil channels 31a are communicated with the plurality of axial oil channels 31b, and two ends of the plurality of axial oil channels 31b can be communicated to two ends of the rotor assembly 2 through oil channels, so as to cool the rotor assembly 2. The cooling oil flowing in from the communication port 11a at the side of the stator assembly 1 and the cooling oil flowing in from the axial oil duct 31b are led into the middle magnetic steel of the rotor assembly 2 through the magnetic steel groove of the rotor assembly 2, and the rotor core and the magnetic steel of the rotor assembly 2 are also cooled in an immersed mode, so that heat of the rotor core and the magnetic steel is directly taken away, the magnetic steel of the rotor assembly 2 works at a lower temperature, demagnetizing risks are reduced, and meanwhile, the performance of the motor can be improved.

The embodiment of the application also provides a generator and a hybrid electric vehicle with the same, wherein the generator comprises the cooling system of the motor, which has the same technical effects and is not repeated. The working mode of the generator can comprise starting the engine, generating electricity, assisting in driving and recovering the capacity, is one of core components of a hybrid system of the hybrid electric vehicle, and particularly has short winding end part and compact structure of a stator assembly formed by combining a plurality of stator units; and the stator assembly is divided into circles, so that higher slot filling rate can be realized, the motor efficiency is high, the motor high-efficiency area is matched with the engine high-efficiency area, and the motor is very suitable for a generator for a hybrid power system.

The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the method of the present invention and its core ideas. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims.

Claims

1. The cooling system of the motor is characterized by comprising a stator shell and a stator assembly positioned on the inner side of the stator shell, wherein the stator assembly comprises a stator winding and a stator framework used for winding the stator winding, one end of the stator shell is provided with an annular end cover, and the stator framework, the stator shell and the end cover are enclosed to form an annular cooling cavity; the annular cooling cavity is provided with an oil inlet.

2. The cooling system of an electric machine of claim 1, wherein the oil inlet is disposed at an end of the annular cooling cavity proximate the end cap.

3. The electric machine cooling system of claim 2, wherein the annular cooling cavity includes two of the oil inlets, both disposed in the stator housing; the two oil inlets are symmetrically arranged in the radial direction or the axial direction of the annular cooling cavity is horizontal, and the two oil inlets are arranged at the top of the stator housing.

4. The motor cooling system according to claim 2, wherein a communication port is provided on a radially inner side of the stator frame at the other end opposite to the oil inlet port, the communication port communicating with a rotor assembly of the motor.

5. The cooling system of an electric machine according to claim 4, wherein the stator assembly includes a plurality of stator units distributed in a circumferential direction, each of the stator units including a stator single tooth, an insulation skeleton wrapped around a tooth portion of the stator single tooth, and a single-tooth winding wound around the insulation skeleton, a plurality of the insulation skeletons being spliced in the circumferential direction to form the stator skeleton, side edges of radially inner sides of adjacent ones of the insulation skeletons being abutted;

6. The motor cooling system of claim 1, further comprising an oil pipe in communication with the oil inlet of the annular cooling cavity, the oil pipe being provided with a first oil hole in communication with the oil inlet and a second oil hole injecting cooling oil toward an outer surface of the stator housing.

7. The cooling system of an electric machine according to any one of claims 1-4, 6, wherein the stator assembly includes a plurality of circumferentially distributed stator units, each of the stator units including a stator single tooth, an insulating bobbin wrapped around a tooth portion of the stator single tooth, and a single tooth winding wound around the insulating bobbin, a plurality of the insulating bobbins being circumferentially split to form the stator bobbin, a radially inner side edge of an adjacent one of the insulating bobbins being abutted.

8. The cooling system of an electric machine of claim 7, wherein the end cap is a slip ring that is electrically connected to a plurality of the single tooth windings simultaneously.

9. A generator comprising a cooling system of the electric machine of any one of claims 1-8.

10. A hybrid vehicle comprising the generator of claim 9.