CN110365137A - A motor cooling mechanism - Google Patents

Abstract

The invention discloses a motor cooling mechanism, comprising a casing, a cavity capable of accommodating a stator iron core is arranged in the casing; a plurality of intermediate guide grooves are arranged on the inner surface of the casing, and the stator iron core The outer surface forms an intermediate cooling channel with the intermediate guide groove, and the adjacent intermediate cooling channels are connected end to end; a groove ring is arranged inside the casing at the position corresponding to the motor end winding, and the groove ring has a groove ring. The groove and the inner surface of the casing form an end cooling channel; the end cooling channel communicates with the intermediate cooling channel to form a complete cooling channel; the casing is provided with a cooling liquid inlet connected to the head end of the cooling channel, There is also a cooling liquid outlet connected with the rear end of the cooling channel; the bottom of the groove ring and the end winding are filled with thermally conductive and heat-insulating material. The invention can improve the heat dissipation performance of the end winding and the stator core.

Description

A motor cooling mechanism

technical field

The invention relates to a motor cooling mechanism and belongs to the technical field of motors.

Background technique

Permanent magnet motors have the advantages of small size, high power density, strong overload capacity, wide speed regulation range, and high reliability, and are widely used in electric vehicles and other fields.

When the permanent magnet motor is running under load, the winding will produce copper loss, and the copper loss of the winding will increase with the increase of load and temperature. Hysteresis loss and eddy current loss, in addition, wind friction loss and bearing friction loss will occur when the motor is running. These losses will generate heat in the motor and eventually cause the motor temperature to rise, especially when the motor runs at low speed and high torque. Under the working conditions, the heat generation per unit volume of the motor will be more serious, and the high temperature will seriously affect the insulation life of the motor and the performance of the permanent magnet.

In the prior art, permanent magnet motors for vehicles usually use the middle layer of the casing to open a cooling channel. The cooling liquid in the casing can greatly reduce the temperature of the motor. The heat conduction layer of the cooling liquid can not fully exert the heat dissipation performance of the cooling liquid; usually, the heat at the end of the winding is mainly conducted to the windings in the stator core through heat conduction, and then passes through the motor core and the casing and is finally taken away by the cooling liquid. The air around the inner end winding has poor fluidity and high air thermal resistance. The heat directly transmitted to the casing through the end air is very small, resulting in a high temperature of the end winding. At present, the cooling of the end winding of the permanent magnet motor for vehicles is still a problem. Hot Issues.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies in the prior art, and to provide a motor cooling structure, which can improve the heat dissipation performance of the end windings and the stator core.

In order to achieve the above purpose, the present invention is realized by adopting the following technical solutions: a motor cooling mechanism, comprising a casing, wherein a cavity capable of accommodating a stator iron core is arranged in the casing; There are a plurality of intermediate diversion grooves, the outer surface of the stator iron core and the intermediate diversion grooves form intermediate cooling channels, and the adjacent intermediate cooling channels are connected end to end; There is a groove ring, and the groove of the groove ring forms an end cooling channel with the inner surface of the casing; the end cooling channel is communicated with the intermediate cooling channel to form a complete cooling channel; the casing is provided with a cooling channel. There is a cooling liquid inlet connected with the head end of the cooling channel, and a cooling liquid outlet connected with the tail end of the cooling channel.

Further, the end of the groove ring close to the stator core contains the inner ring of the groove ring, the end of the groove ring far from the stator core contains the outer ring of the groove ring, the inner ring of the groove ring and the outer side of the groove ring. The ring and groove together form a complete groove ring.

Further, the groove ring and the end face of the stator iron core, the outer surface of the stator iron core and the contact surface of the casing are fixed by fasteners and a sealant layer.

Further, a thermally conductive insulating material is filled between the groove ring and the motor end winding.

Further, the inner surface of the casing is further provided with a communication groove, and the outer surface of the stator core and the communication groove form a communication channel connecting the cooling channels at both ends;

One end cooling channel communicates with the adjacent intermediate cooling channel;

The cooling channel at the other end is connected to the cooling liquid inlet as the head end of the cooling channel, and the intermediate cooling channel adjacent thereto is connected to the cooling liquid outlet as the tail end of the cooling channel.

Further, the groove ring is made of non-magnetic alloy material.

Compared with the prior art, the beneficial effects achieved by the present invention are:

The heat dissipation capacity of the stator iron core is improved by eliminating the installation gap between the casing and the stator iron core and the heat transfer layer of the inner wall thickness of the casing, and the thermal resistance between the casing and the end winding is shortened by the groove ring, which helps to improve the end winding. The heat dissipation performance of the windings; the thermal conductive insulating material is filled between the groove ring and the end winding, which can transfer the heat energy of the end winding to the groove ring through the thermal conductive insulating material, and the heat is taken away by the cooling liquid in the groove, and further Improve the heat dissipation performance of the end windings. The invention is especially suitable for the permanent magnet synchronous motor for high power density vehicle.

Description of drawings

1 is a schematic structural diagram of a motor cooling mechanism provided by an embodiment of the present invention;

2 is a schematic diagram of the assembly structure of a casing and a groove ring in an embodiment of the present invention;

3 is a schematic structural diagram of a groove ring in an embodiment of the present invention;

4 is a schematic structural diagram of a cooling channel in an embodiment of the present invention;

5 is a schematic diagram of the assembly structure of the stator winding and the end winding in the embodiment of the present invention, wherein the end winding is equivalent to a circular ring;

6 is a schematic structural diagram of a stator core in an embodiment of the present invention;

7 is a comparison diagram of the overall temperature distribution of the motor using the existing motor cooling mechanism and the motor cooling mechanism using the embodiment of the present invention;

8 is a comparison diagram of the temperature distribution of the motor windings in the motor using the existing motor cooling mechanism and the motor using the motor cooling mechanism according to the embodiment of the present invention;

9 is a comparison diagram of the temperature distribution of the stator in the motor using the existing motor cooling mechanism and the motor using the motor cooling mechanism according to the embodiment of the present invention;

FIG. 10 is a comparison diagram of the flow rate distribution of the cooling liquid of the existing motor cooling mechanism and the present invention;

In the figure: 1-coolant inlet; 2-coolant outlet; 3-cooling channel; 4-chassis; 5-chassis channel baffle; 6-groove ring; 7-stator core; 8-winding insulation layer ;9-straight copper winding;10-end winding;11-thermal insulating material;12-inner ring of groove ring;13-outer ring of groove ring;14-bottom of groove ring;15-first end 16-communication channel; 17-second end cooling channel; 18-intermediate cooling channel; 19-stator outer circumferential surface; 20-stator core end surface.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solutions of the present invention more clearly, and cannot be used to limit the protection scope of the present invention.

It should be noted that, in the description of the present invention, the terms "front", "rear", "left", "right", "upper", "lower", "inner", "outer" and the like indicate the orientation or position The relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention rather than requiring the present invention to be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. The terms "front", "rear", "left", "right", "upper" and "lower" used in the description of the present invention refer to the directions in the drawings, and the terms "inner" and "outer" respectively refer to is the direction toward or away from the geometric center of a particular part.

As shown in FIGS. 1 to 6 , it is a motor cooling mechanism provided by an embodiment of the present invention, which includes a cylindrical casing 4 . The casing 4 is provided with a cavity capable of accommodating the stator core 7 . The surface is provided with a plurality of intermediate cooling grooves along the circumferential direction. The adjacent intermediate cooling grooves are isolated from each other by the casing channel baffle 5. The stator iron core 7 and the intermediate cooling grooves form intermediate cooling passages 18, and the adjacent intermediate cooling passages 18 are connected end to end. .

The stator core 7 includes a winding insulating layer 8 and a straight segment copper winding 9 in the slot.

A groove ring 6 is provided inside the casing 4 at a position corresponding to the motor end winding 10 , and a thermally conductive insulating material 11 is filled between the groove ring 6 and the motor end winding 10 . The grooves of the groove ring 6 are arranged on the outer circumferential surface of the groove ring 6 and are distributed along the circumferential direction of the groove ring 6 . The grooves and the inner surface of the casing 4 form end cooling channels. The motor cooling mechanism provided in the embodiment of the present invention enables the groove ring 6 to be integrated with the motor end winding 10 through the thermally conductive insulating material 11. Compared with the traditional motor, the heat of the motor end winding 10 can be conducted to the motor through the thermally conductive insulating material 11. The groove ring 6 is taken away by the cooling liquid passing through the groove quickly, so that the temperature of the motor end winding 10 is rapidly and significantly reduced.

A communication groove is also provided inside the casing 4 along the axial direction. The communication groove and the outer surface of the stator core 7 form a communication channel 16. The communication channel is preferably a straight line for connecting the cooling channels at both ends. For the convenience of description, the cooling channels at both ends are now referred to as the first end cooling channel 15 and the second end cooling channel 17 respectively. The second end cooling channel 17 communicates with the adjacent intermediate cooling channel 18 , and the intermediate cooling channel 18 adjacent to the first end cooling channel 15 is connected to the cooling liquid outlet 2 as the rear end of the cooling channel 3 .

In the motor cooling mechanism provided by the embodiment of the present invention, the cooling liquid flows in sequence: the cooling liquid inlet 1, the first end cooling channel 15, the communication channel 16, the second end cooling channel 17, the intermediate cooling channel 18, and the cooling liquid outlet 2 , it can ensure that the low-temperature coolant preferentially passes through the end cooling channel 3, which can greatly reduce the temperature of the motor end winding 10, and at the same time, the cooling channel 3 eliminates the installation gap between the casing 4 and the stator core 7 and the heat transfer in the inner layer of the casing 4. The heat dissipation capacity of the stator core 7 is improved; and the thermal resistance between the casing 4 and the end winding 10 can be shortened by the groove ring 6 , which helps to improve the heat dissipation performance of the end winding 10 .

One end of the groove ring 6 close to the stator core 7 contains the inner ring 12 of the groove ring, and the inner ring 12 of the groove ring is fixed between the casing 4 and the outer surface of the stator core 7, and is fixed to the casing 4 by a sealant connect. The contact surface between the groove ring 6 and the end surface of the stator core 7 is fixedly connected by sealant, and the radial width of the contact surface is less than or equal to the length of the stator yoke.

One end of the groove ring 6 away from the stator core 7 contains an outer ring 13 of the groove ring, which is fixedly connected to the casing 4 through fasteners (or clamping grooves) and sealants. The groove ring 6 is made of non-magnetic alloy material.

The outer surface of the stator core 7 needs to be treated with anti-rust and waterproof treatment.

The invention has the advantages of compact structure, convenient manufacture and obvious cooling effect, and can effectively reduce the influence of high temperature on the insulation and permanent magnet demagnetization of the permanent magnet motor when applied to the permanent magnet motor, and improve the running performance and reliability of the motor.

In order to verify the cooling effect of the embodiment of the present invention, the present invention is further described below with reference to simulation.

1. Motor model: According to a vehicle prototype, the two simulation models do not consider the rotor iron core, permanent magnet, rotating shaft and end cover of the motor, and the stator iron core and winding parts are completely consistent. The 10 end rings of the end windings are equivalent to Ring, the original model casing 4 is a traditional prototype structure, and the new model casing 4 is a patented casing 4 structure.

2. Loss source and distribution: The loss comes from the prototype, and is applied to the winding and the stator core 7 according to the copper loss and iron loss, and some mechanical losses are considered on the stator core 7, and the loss distribution of the two models is consistent.

3. Materials: The materials of the two models are the same, and the new model adds thermally conductive insulating material 11 (thermal conductivity 0.4W/m.k, specific heat capacity 850j/kg.k, temperature range -40℃-230℃, field strength ≥27kV/mm).

4. Fluid: The fluid properties, flow rate, inlet temperature (330K), and ambient temperature are all the same.

5. Simulation verification: As shown in Figures 7 to 9, it is a comparison diagram of the temperature distribution of the motor using the existing motor cooling mechanism and the motor cooling mechanism using the embodiment of the present invention. As shown in Table 1, it is a temperature data table of the motor windings and the stator core 7 using the existing motor cooling mechanism and the motor cooling mechanism of the embodiment of the present invention.

Table 1 Data comparison between the original model and the new model (K)

The simulation shows that the maximum temperature of the end winding 10 of the new model is 383.2K, and the maximum temperature of the winding is reduced by 4.9; the maximum temperature of the iron core of the new structure is 360.9K, and the maximum temperature of the iron core is reduced by 3.3K; and the temperature distribution of the new model is more uniform.

The thermal conductivity of the existing thermally conductive insulating materials 11 in the market is generally greater than or equal to 0.4W/m.k. If a thermally conductive insulating material 11 with better thermal conductivity is selected, the temperature of the motor will be further reduced.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the technical principle of the present invention, several improvements and modifications can also be made. These improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims (6)

1. a kind of motor cooling mechanism, which is characterized in that including casing, the sky that can accommodate stator core is equipped in the casing Chamber；The inner surface of the casing is equipped with multiple intermediate diversion trenches, and the outer surface of stator core and the intermediate return guide trough are in Between cooling duct, adjacent cooling during rolling channel is end to end；It is set at the casing internal and motor End winding opposite position Fluted ring, the groove and casing inner surface of the groove ring form end cooling duct；The end cooling duct and centre Cooling duct is connected, and forms a complete cooling duct；The casing is equipped with the cooling being connected with cooling duct head end Liquid entrance is additionally provided with the cooling liquid outlet being connected with cooling duct tail end.

2. motor cooling mechanism according to claim 1, which is characterized in that the groove ring is close to one end of stator core Containing side ring in fluted ring, groove ring contains fluted ring outer annular, side ring in groove ring far from one end of stator core A complete groove ring is collectively formed with groove ring outer annular and groove.

3. motor cooling mechanism according to claim 2, which is characterized in that the groove ring and stator core end face are determined Sub- core exterior surface and chassis contact face are fixed using fastener and sealant layer.

4. motor cooling mechanism according to claim 2, which is characterized in that between the groove ring and motor End winding Filled with heat-conducting insulation material.

5. motor cooling mechanism according to claim 1, which is characterized in that the inner surface of the casing is additionally provided with connection Slot, the outer surface of the stator core form the communicating passage for being connected to both ends cooling duct with connectivity slot；Wherein one end is cold But channel is connected to adjacent cooling during rolling channel；

The other end cooling duct connects coolant inlet, cooling during rolling channel conduct adjacent thereto as cooling duct head end Cooling duct tail end connects cooling liquid outlet.

6. motor cooling mechanism according to any one of claims 1 to 5, which is characterized in that the groove ring is by non-magnetic Alloy material is made.