CN217692983U - A high-speed iron permanent magnet motor cooling system with enhanced thermal management - Google Patents

Abstract

The utility model discloses a heat dissipation system for a high-speed iron permanent magnet motor with enhanced thermal management. The motor includes a water-cooled casing, a stator iron core, a stator winding, a heat pipe, a mounting hole, a cooling water channel, and a heat-conducting potting compound; a cavity is enclosed between the stator winding, the stator iron core, and the water-cooled casing; the water-cooled casing and Both ends of the stator iron core are provided with installation holes; the heat pipe condensation section is embedded in the installation holes of the water-cooled casing and contacts the inner surface of the water-cooled casing of the machine; the heat pipe evaporation section extends into the installation holes of the stator iron core, and the cavity is filled with The thermally conductive potting glue completely wraps the end winding and the heat pipe; the thermally conductive potting glue is filled with quartz powder to improve the thermal conductivity of the thermally conductive potting glue and reduce the contact thermal resistance between the winding and the heat pipe. The utility model utilizes heat pipes and heat-conducting potting glue to provide additional heat paths for the stator iron core and winding ends of the motor, which can eliminate the overheating problem of the stator iron core and the stator winding ends and ensure the working efficiency and service life of the water-cooled motor.

Description

A cooling system for high-speed rail permanent magnet motors with enhanced thermal management

technical field

The utility model relates to the cooling field of high-speed rail permanent magnet traction motors, in particular to a cooling system for high-speed rail permanent magnet motors with enhanced thermal management.

Background technique

With the improvement of permanent magnet motor manufacturing technology and the development of high-performance permanent magnet materials, the motor capacity and power density are increasing. Permanent magnet synchronous traction motors are gradually used in the field of rail transit and become the main line of development of AC drive traction systems. In order to improve the reliability of the permanent magnet motor used in rail transit, the permanent magnet motor needs to be designed as a fully enclosed structure. However, permanent magnet synchronous traction motors for high-speed railways have high power density and high loss density, and the fully enclosed structure makes the cooling conditions relatively harsh. Traditional natural convection cooling cannot ensure that the windings, rotors, permanent magnets and bearings of the motor under different working conditions The temperature rise of key parts is within reasonable limits and has a reasonable temperature distribution. Therefore, in the contradiction between high power density and motor cooling performance, the problem of thermal management of permanent magnet motors needs to be solved urgently.

Common cooling methods for motors include forced air cooling and casing water cooling. Due to its low cost and simple mechanism, forced air cooling has become the most commonly used cooling method for low and medium power motors. However, its low convective cooling efficiency limits its application in medium and high power motors. The water-cooled heat dissipation system of the chassis has a high heat dissipation efficiency, and its heat dissipation efficiency can reach 50 times that of the former. However, limited by the internal structure of the motor, the end winding is surrounded by air, only a small part of the heat is transferred to the casing and end cover through the air at the end of the motor by heat convection, and most of the heat is transferred to the middle of the winding to the iron core. Both the end of the stator core and the winding show a distribution trend of high temperature at both ends and low temperature in the middle, and the temperature uniformity deteriorates. In recent years, the motor heat dissipation scheme that uses high thermal conductivity heat transfer devices such as heat-conducting potting glue and heat pipes as an additional heat circuit is an effective means to solve the heat dissipation problem of the key heat-generating components of the motor, and it also provides a new idea to improve the heat dissipation efficiency of the motor.

Utility model content

In order to overcome the deficiencies such as inability to cool the stator core end and winding end of the high-speed iron permanent magnet motor, large temperature gradient, and poor heat dissipation effect, the utility model provides a high-speed iron permanent magnet motor heat dissipation system with enhanced thermal management. The heat pipe and heat-conducting potting compound are used to provide an additional heat path for the motor stator core and winding ends, reducing the temperature rise of the stator core and winding ends.

The purpose of the utility model is to provide a high-speed iron permanent magnet motor heat dissipation system with enhanced thermal management, including a water-cooled casing, a stator core, a stator winding, a heat pipe, a mounting hole, a cooling water channel, and a heat-conducting potting glue; the stator core is installed in a water-cooled On the inner wall of the casing, there are installation holes at both ends of the water-cooled casing; several heat pipes are arranged between the stator core and the water-cooled casing; the heat generated by the stator core is conducted to the inner wall of the casing through the heat pipes.

The heat-conducting potting compound is filled in the cavity enclosed between the stator core, the stator winding and the water-cooled casing, and completely wraps the end winding and the heat pipe.

A cooling water channel is arranged in the water-cooling casing, and a cooling water inlet and outlet are arranged on the water-cooling casing, and the axial length of the cooling water channel is longer than that of the stator winding.

The condensing section of the heat pipe is embedded in the installation hole of the water-cooled casing and contacts the inner surface of the water-cooled casing; the evaporating section of the heat pipe is assembled in the heat pipe installation hole of the stator core.

The heat pipe is a copper heat pipe with a sintered capillary liquid-absorbing core, and the liquid-absorbing core on the inner wall is made of capillary porous material.

The heat pipes are divided into two groups and placed at both ends of the motor. One group of heat pipes corresponds to one cavity. Each group of heat pipes includes a plurality of heat pipes. The heat pipes of the same group are evenly distributed on one end of the water-cooled casing along the circumference and the number of installation holes is The number of heat pipes is kept consistent to meet the requirement of consistent heat dissipation performance at both ends of the high-speed iron permanent magnet motor.

Further, the cross section of the installation hole is circular or semicircular, and the cross section of the heat pipe is circular.

Further, the installation hole on the stator core and the heat pipe are connected by expansion joints, and the installation hole on the water-cooled casing and the heat pipe are connected by low-temperature welding.

Further preferably, the outer surface of the condensing section of the heat pipe and the evaporating section embedded in the heat-conducting potting compound has spiral grooves or fins.

Further preferably, in order to improve the thermal conductivity of the heat-conducting potting compound, the heat-conducting potting compound is filled with quartz powder.

Further preferably, the surface of the heat pipe is passivated to reduce wear and corrosion of the shell of the heat pipe and prevent leakage of working fluid inside the heat pipe.

Further preferably, the working fluid poured into the heat pipe is a cold medium. The cold medium should choose a cold medium with high vaporization latent heat and thermal conductivity to reduce the amount of cold medium and heat pipe volume, such as deionized water.

Compared with the prior art, the utility model has the following effects:

(1) The utility model uses a heat pipe as a heat-conducting component. The heat pipe has a very high heat transfer efficiency, which can enhance the heat transfer efficiency of the stator core, stator winding and water-cooled casing, so that the heat originally concentrated on the stator winding and the end of the stator core Rapid transmission and diffusion to the entire water-cooled casing, reducing the temperature gradient of the stator core and windings, thereby eliminating the problem of local overheating.

(2) The heat-conducting potting compound is filled with quartz powder. Quartz powder has superior insulation properties, low price and high thermal conductivity. It is suitable for potting and can improve the thermal conductivity of the heat-conducting potting compound, thereby reducing the contact between the heat pipe and the winding. thermal resistance.

(3) There are spiral grooves or fins on the outer surface of the condensing section of the heat pipe and the evaporating section sealed in the heat-conducting potting compound, which can increase the heat exchange area, reduce the temperature gradient, and realize enhanced heat transfer.

(4) The heat pipe has a small radius and can bend in any direction, so it can make full use of the extra small space between the stator winding in the motor and the water-cooled casing, without additionally expanding the volume of the motor, which is convenient for the integration of the motor and other objects.

Description of drawings

Figure 1 is a three-dimensional schematic diagram of a high-speed rail permanent magnet motor cooling system with enhanced thermal management;

Figure 2 is an assembly drawing of a water-cooled casing and stator core for a high-speed rail permanent magnet motor cooling system with enhanced thermal management;

Fig. 3 is a cross-sectional view of a high-speed rail permanent magnet motor heat dissipation system with enhanced thermal management;

Figure 4 is an exploded view of a high-speed rail permanent magnet motor cooling system with enhanced thermal management;

Description of reference numerals among Fig. 1 to Fig. 4:

1-Water-cooled casing; 2-Stator core; 3-Stator winding; 4-Heat pipe; 5-Installation hole; 6-Cooling water channel;

Detailed ways

In the following, the specific implementation of the utility model will be further described in conjunction with the accompanying drawings, so that the technical solution of the utility model and its beneficial effects will be clearer and more definite. The embodiments described below by referring to the figures are exemplary and intended to explain the present invention, but the scope and implementation of the present invention are not limited thereto.

As shown in Figures 1 to 4, the utility model provides a high-speed iron permanent magnet motor heat dissipation system with enhanced thermal management, including a water-cooled casing 1, a stator core 2, a stator winding 3, a heat pipe 4, a mounting hole 5, a cooling Water channel 6, heat conduction potting glue 7, rotor 8, permanent magnet 9, bearing 10.

The three-dimensional schematic diagram of the heat dissipation system of the high-speed iron permanent magnet motor is shown in Figure 1; the water-cooled casing 1 is provided with a cooling water channel 7, the cooling water channel 6 in the water-cooled casing 1, and the cooling water channel 6 is provided with a cooling liquid inlet and outlet , and the axial length of the cooling water channel 6 is greater than that of the stator winding 3; the two ends of the water-cooled casing 1 have mounting holes 5, and the heat pipes 4 are divided into two groups and placed at both ends of the motor. A group of heat pipes corresponds to a cavity, each Each group of heat pipes includes a plurality of heat pipes 4, and the same group of heat pipes 4 is evenly distributed on one end of the water-cooled casing 1 along the circumference, and the number of mounting holes 5 is consistent with the number of heat pipes 4, so as to meet the same heat dissipation performance at both ends of the high-speed iron permanent magnet motor. Require.

The stator core 2 is installed in the water-cooled casing 1, and the outer peripheral surface of the stator core 2 is in contact with the inner wall of the water-cooled casing 1.

The length of the stator core 2 is shorter than the stator winding 3 and the water-cooled casing 1, so an annular cavity is enclosed between the three.

The heat pipe 4 is a copper heat pipe with a sintered capillary liquid-absorbing core; the condensation section of the heat pipe 4 is embedded in the installation hole 5 of the water-cooled casing 1 and contacts the inner surface of the water-cooled casing 1; the evaporation section of the heat pipe 4 extends to the stator iron In the installation hole 5 of the core 2 , the cavity is filled with a heat-conducting potting compound 7 , and the heat-conducting potting compound 7 completely wraps the end winding 3 and the heat pipe 4 .

The surface of the heat pipe 4 is passivated to reduce the wear and corrosion of the outer shell of the heat pipe 4 and prevent leakage of the internal working fluid of the heat pipe 4.

Both the condensation section of the heat pipe 4 and the evaporation section wrapped in the heat-conducting potting compound 7 have spiral grooves or fins on the outer surface.

The heat-conducting potting compound 7 is filled with quartz powder, which has superior insulation properties, low price and high thermal conductivity, is suitable for potting, and can improve the thermal conductivity of the heat-conducting potting compound, thereby reducing the contact between the heat pipe and the winding thermal resistance.

The cross-sectional shape of the mounting hole 5 is circular or semicircular; the cross-section of the heat pipe 4 is circular, and its diameter can be reasonably designed according to the iron loss and torque of the motor. The working fluid inside the heat pipe 4 is a cold medium, such as deionized water .

Further, in order to reduce the contact thermal resistance between the heat pipe 4 and the stator core 2 and the water-cooled casing 1, the installation hole 5 on the stator core 2 and the heat pipe 4 are connected by expansion joints; the installation on the water-cooled casing 1 The hole 5 and the heat pipe 4 are connected by low-temperature welding.

In order to ensure that the cooling medium in the heat pipe 4 can evaporate and condense normally, the boiling point of the cooling medium should be higher than the temperature of the cooling water in the water-cooled casing 1 and lower than the temperature of the stator core 2 in the evaporation section of the heat pipe 4 . For example, when the cooling medium is deionized water, the internal pressure of the heat pipe 4 can be about 38kpa, and the boiling point of the cooling medium is 75° C., which is lower than the steady-state temperature of the stator core 2 of the motor.

A distance of 2-3 mm should be maintained between the heating section of the heat pipe 4 and the stator winding 3 to ensure the insulation requirements of the motor.

The cooling method of above-mentioned motor, comprises following process:

During the working process of the motor, the internal temperature of the motor rises, and the heat generated by the stator core 2 and the stator winding 3 is transmitted to the heat pipe 4 through the heat-conducting potting glue 7, and the refrigerant medium in the heat pipe 4 absorbs heat in the evaporation section and evaporates to form steam It flows to the condensing section, and is condensed into a liquid in the condensing section to transmit latent heat to the water-cooled casing 1. The condensed liquid flows back to the evaporating section by the capillary force of the liquid-absorbing wick to absorb heat and evaporate again, and so on.

The thermal conductivity potting compound 7 is filled with quartz powder, the higher thermal conductivity of the quartz powder can improve the thermal conductivity of the heat conductive potting compound 7, thereby reducing the contact thermal resistance between the heat pipe and the winding.

The water-cooled motor described in this embodiment provides an additional thermal circuit for the motor stator core and the end of the winding by using the heat pipe and the heat-conducting potting glue, thereby eliminating the problem of overheating of the stator core and the end of the stator winding, and ensuring the operation of the water-cooled motor efficiency and service life.

The above embodiment is a preferred embodiment of the present utility model, but the embodiment of the present utility model is not limited thereto, and any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present utility model are all All equivalent replacement methods are included in the protection scope of the present utility model.

Claims (5)

1. A high-speed rail permanent magnet motor heat dissipation system for enhancing heat management comprises a water cooling machine shell, a heat pipe, a cooling water channel and heat conduction pouring sealant, wherein the cooling water channel is arranged in the water cooling machine shell; enclose into between stator winding, stator core, the water-cooled casing and hold the chamber, its characterized in that: mounting holes are formed in the two ends of the water-cooling shell and the two ends of the stator iron core; the heat pipe comprises a heat pipe condensation section and a heat pipe evaporation section; the heat pipe condensation section is assembled in the mounting hole of the water-cooling shell; the heat pipe evaporation section extends into the mounting hole of the stator core, the cavity is filled with heat conduction pouring sealant, and the end winding and the heat pipe are completely wrapped by the heat conduction pouring sealant.

2. The high-speed rail permanent magnet motor heat dissipation system for enhanced thermal management of claim 1, wherein: the heat pipes are divided into two groups and are arranged at two ends of the motor in a separated mode, one group of heat pipes corresponds to one containing cavity, each group of heat pipes comprises a plurality of heat pipes, and the heat pipes in the same group are uniformly distributed at one end of the water cooling shell along the circumference so as to meet the requirement that the heat dissipation performance of two ends of the high-speed rail permanent magnet motor is consistent.

3. The high-speed rail permanent magnet motor heat dissipation system for enhanced thermal management of claim 1, wherein: the heat pipe condensation section is assembled in the mounting hole of the water-cooling shell and is contacted with the inner surface of the water-cooling shell; the heat pipe evaporation section is assembled in a heat pipe mounting hole of the stator core.

4. The high-speed rail permanent magnet motor heat dissipation system for enhanced thermal management of claim 1, wherein: and quartz powder is filled in the heat-conducting pouring sealant and completely wraps the end winding and the heat pipe.

5. The enhanced thermal management high-speed rail permanent magnet motor heat dissipation system of any of claims 1 to 4, wherein: the heat pipe is fixedly sealed on the outer surface of the part of the heat conduction pouring sealant, and a spiral groove or a fin is arranged on the outer surface of the part of the heat conduction pouring sealant.

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