A phase change heat transfer motor stator heat dissipation structure and design method

Abstract

This invention discloses a phase-change heat transfer motor stator heat dissipation structure and design method, belonging to the field of motor thermal management technology. The structure includes a stator core, copper wire windings, and a flattened phase-change heat transfer device. The copper wire windings are arranged inside the stator core, and the flattened phase-change heat transfer device is arranged in a slot radially inward of the copper wire windings, in contact with the stator core. A design method for the heat dissipation structure is also disclosed. The present invention utilizes this heat dissipation structure and design method to develop thermal control technology for motor stator windings based on phase-change heat transfer devices, achieving the goals of significantly reducing motor peak temperature, enhancing motor temperature uniformity, and ensuring safe operation at high overload multiples.

Description

Technical Field

[0001] The present invention relates to the technical field of motor thermal management, and in particular to a phase change heat transfer motor stator heat dissipation structure and a design method thereof. Background Art

[0002] With the rapid development of new energy vehicles, performance requirements for the motors that drive them are becoming increasingly stringent. While existing oil-cooled motors offer a temperature improvement compared to water-cooled motors, internal high temperatures still exist. Under extreme high-power operating conditions such as starting, climbing, accelerating, and braking, internal temperature differences can reach over 70°C, potentially leading to serious failures such as motor burnout.

[0003] Therefore, there is an urgent need to invent a heat dissipation structure inside a motor to improve the heat dissipation efficiency of the motor. Summary of the Invention

[0004] The purpose of the present invention is to provide a phase change heat transfer motor stator heat dissipation structure and design method, and to develop motor stator winding thermal control technology based on phase change heat transfer devices, so as to achieve the purpose of significantly reducing the peak temperature of the motor, enhancing the temperature uniformity of the motor, and ensuring safe operation at high overload multiples.

[0005] To achieve the above objectives, the present invention provides a method for designing a heat dissipation structure of a phase change heat transfer motor stator, the steps comprising:

[0006] S1. Obtain the geometric parameters of the copper wire winding and stator core in the motor;

[0007] S2. Customize and process the slots in the radial direction of the copper wire winding that contact the stator core according to the geometric parameters of the stator core;

[0008] S3. Designing a flattened phase change heat transfer device and layout parameters based on the geometric parameters obtained in S1;

[0009] S4. Pre-process the flattened phase change heat transfer device according to geometric parameters and layout parameters, and then pre-fix it, installing the flattened phase change heat transfer device in a slot radially inside the copper wire winding that contacts the stator core;

[0010] S5. After being fixed, heat the flattened phase-change heat transfer device and use a mold to press the flattened phase-change heat transfer device to expand the flattened phase-change heat transfer device toward the circumference of the stator core, so that the flattened phase-change heat transfer device fits tightly with the stator core and does not exceed the inner radius of the stator core.

[0011] Preferably, the geometric parameters of the copper wire winding and the stator core in S1 include: the cross-sectional diameter, cross-sectional shape, thickness of the copper wire winding, the spacing between the copper wire winding and the rotor, and the cross-sectional shape and area of ​​the slot in the radial inner part of the winding that contacts the stator core.

[0012] Preferably, the slot in the radially inner portion of the copper wire winding in S2 that contacts the stator core includes a slot height and a slot depth.

[0013] Preferably, the S3 design of the flattened phase change heat transfer device includes designing a linear flattened phase change heat transfer device and a bent flattened phase change heat transfer device. The design parameters of the linear flattened phase change heat transfer device include the length and diameter before flattening and the width and height after flattening. The design parameters of the bent flattened phase change heat transfer device include the bending angle, thickness, cross-sectional size and cross-sectional shape.

[0014] Preferably, the arrangement parameters of the flattened phase change heat transfer devices in S3 include the number, arrangement positions and arrangement angles of the flattened phase change heat transfer devices.

[0015] The present invention also provides a phase change heat transfer motor stator heat dissipation structure, including a stator core, a copper wire winding and a flattened phase change heat transfer device, wherein the copper wire winding is arranged on the inner side of the stator core, and the flattened phase change heat transfer device is arranged in a slot radially inside the copper wire winding and in contact with the stator core.

[0016] Preferably, the end of the flattened phase change heat transfer element extends axially out of the stator core and is in direct contact with the cooling oil.

[0017] Preferably, the flattened phase-change heat transfer device comprises an evaporation section and a condensation section, the condensation sections are located on both sides of the flattened phase-change heat transfer device, and the evaporation section is located between the two condensation sections.

[0018] Preferably, the length of the flattened phase change heat transfer device is 110%-120% of the axial length of the stator core, its width is 85%-95% of the width of the slot in the radial inner part of the winding that contacts the stator core, and its height is 75%-85% of the height of the slot in the radial inner part of the winding that contacts the stator core.

[0019] Preferably, the contact areas between the flattened phase change heat transfer component and the stator core and the copper wire winding are filled with a thermal interface material.

[0020] Therefore, the present invention adopts the above-mentioned phase change heat transfer motor stator heat dissipation structure and design method, which has the following beneficial effects:

[0021] (1) The present invention obtains the geometric parameters of the motor copper wire winding and the stator core, and designs a flattened phase change heat transfer device that fits the copper wire winding and the stator core by processing the corresponding slot width. Through the ultra-high thermal conductivity of the flattened phase change heat transfer device, the heat in the axial direction of the winding is quickly transferred to the two ends, and then the two ends of the flattened phase change heat transfer device are directly in contact with the cooling oil to achieve rapid heat dissipation. Compared with the traditional heat dissipation structure, this heat dissipation structure increases the contact area between the phase change heat transfer device and the winding and the stator core, significantly improves the heat dissipation in the motor, greatly reduces the peak temperature of the motor, and achieves the purpose of safe operation with high overload multiples.

[0022] (2) The cavity between the rotor and stator windings is filled with low-cost and more efficient phase change heat transfer devices, which enhances heat conduction and reduces the heat dissipation cost of the motor.

[0023] (3) The motor structure is optimized based on phase change heat transfer devices that can be customized and industrialized. The implementation method is simple, practical and low-cost.

[0024] (4) The passive design of the phase change heat transfer device means that it does not require an external power source to drive any components, is very reliable during use, has low maintenance costs, and does not generate noise or vibration.

[0025] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the heat dissipation structure of an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the stator core structure according to an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the assembly of a flattened phase change heat transfer device according to an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of a linear flattened phase change heat transfer device according to an embodiment of the present invention;

[0030] Reference numerals

[0031] 1. Stator core; 2. Copper wire winding; 3. Flattened phase change heat transfer device; 31. Evaporation section; 32. Condensation section. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] Example

[0034] Reference Figure 1-4 The present invention provides a phase-change heat transfer motor stator heat dissipation structure. Based on a phase-change heat transfer device, the structure includes a stator core 1, copper wire windings 2, and a flattened phase-change heat transfer device 3. The copper wire windings 2 are disposed inside the stator core 1, and the flattened phase-change heat transfer device 3 is disposed in a slot radially inward of the copper wire windings 2, in contact with the stator core 1. Materials for the flattened phase-change heat transfer device 3 include, but are not limited to, copper, aluminum, its alloys, and stainless steel.

[0035] The ends of the flattened phase-change heat transfer device 3 extend axially from the stator core 1, directly contacting the cooling oil. The length of extension of the flattened phase-change heat transfer device 3 relative to the stator core 1 includes, but is not limited to, symmetrical extension at both ends, one end flush with the other, and different extension lengths at both ends.

[0036] The flattened phase-change heat transfer device 3 includes linear and bent types. The bent portion of the bent type extends beyond the stator core 1. Bent-type flattened heat pipes include, but are not limited to, one end bent, one end unbent, both ends bent, and bends of varying lengths.

[0037] The flattened phase-change heat transfer device 3 includes an evaporation section 31 and a condensation section 32 . The condensation sections 32 are located on both sides of the flattened phase-change heat transfer device 3 , and the evaporation section 31 is located between the two condensation sections 32 .

[0038] The length of the flattened phase change heat transfer device 3 is 110%-120% of the axial length of the stator core 1, its width is 85%-95% of the width of the slot in the radial inner part of the winding that contacts the stator core 1, and its height is 75%-85% of the height of the slot in the radial inner part of the winding that contacts the stator core 1.

[0039] When installing the heat dissipation structure, first install the copper wire winding 2 inside the stator core 1. After installation, spray insulating varnish on it. Then, place the flattened phase-change heat transfer device 3 in the slot radially inward of the stator core 1 winding, where it contacts the stator core 1. The contact area between the flattened phase-change heat transfer device 3, the stator core 1, and the copper wire winding 2 is filled with thermal interface material. Meanwhile, the relative position of the flattened phase-change heat transfer device 3 is fixed with insulating waterproof adhesive. Thermal interface materials include any thermally conductive adhesive, double-sided thermal tape, thermal paste, thermal paste, or other materials that can reduce thermal resistance.

[0040] The present invention also provides a method for designing a heat dissipation structure of a phase change heat transfer motor stator, the steps comprising:

[0041] S1. Obtain geometric parameters of the copper wire winding 2 and the stator core 1 in the motor.

[0042] The geometric parameters of the copper wire winding 2 and the stator core 1 include: the cross-sectional diameter, cross-sectional shape, thickness of the copper wire winding 2, the spacing between the copper wire winding 2 and the rotor, and the cross-sectional shape and area of ​​the slot in the radial inner part of the winding that contacts the stator core 1.

[0043] S2. Customize and process the slots of the copper wire winding 2 radially inwardly contacting the stator core 1 according to the geometric parameters of the stator core 1. The slots of the copper wire winding 2 radially inwardly contacting the stator core 1 include slot height and slot depth.

[0044] There are two ways to customize the slots in the radial direction of the copper wire winding 2 that contact the stator core 1. The two ways are as follows:

[0045] Method 1: When manufacturing the silicon steel sheets of the stator core 1, the slots in the radial direction of the winding that contact the stator core 1 are processed to a corresponding width by stamping in one step so as to accommodate the flattened phase change heat transfer device.

[0046] Method 2: Secondary widening of the stator core 1's slots. The slots radially inward of the windings, where they contact the stator core, are widened to a suitable width to accommodate the flattened phase-change heat transfer element. Secondary widening of the stator core's slots can be performed using methods including, but not limited to, wire cutting, laser cutting, water jet cutting, and plasma cutting.

[0047] S3. Design the flattened phase change heat transfer device 3 and layout parameters according to the geometric parameters obtained in S1.

[0048] Designing a flattened phase-change heat transfer device 3 includes designing a linear flattened phase-change heat transfer device and a bent flattened phase-change heat transfer device. The design parameters for the linear flattened phase-change heat transfer device include its unflattened length and diameter, and its flattened width and height. The design parameters for the bent flattened phase-change heat transfer device include its bending angle, thickness, cross-sectional dimensions, and cross-sectional shape.

[0049] The arrangement parameters of the flattened phase change heat transfer device 3 include the arrangement quantity, arrangement position and arrangement angle of the flattened phase change heat transfer device.

[0050] S4. Pre-process the flattened phase-change heat transfer device 3 based on its geometric and layout parameters, then pre-fix it. Install it in the slot radially inward of the copper winding 2, where it contacts the stator core 1. Tools used to secure the flattened phase-change heat transfer device include waterproof insulating glue, stoppers, and other tools.

[0051] S5. After being fixed, the flattened phase-change heat transfer device 3 is heated and pressed with a mold so that the flattened phase-change heat transfer device 3 expands circumferentially rather than radially around the stator core. This ensures that the flattened phase-change heat transfer device 3 fits tightly against the stator core 1 and does not extend beyond the inner radius of the stator core.

[0052] Specifically, the bent and flattened phase change heat transfer device is heated to 180-200° C., thermally expanded, and then cooled so that the bent and flattened heat pipe has an interference fit with the groove in the width direction.

[0053] Therefore, the present invention adopts the above-mentioned phase change heat transfer motor stator heat dissipation structure and design method. The part of the stator core extending out of the end of the flattened phase change heat transfer device is in direct contact with the cooling oil. The ultra-high thermal conductivity of the flattened phase change heat transfer device is utilized to quickly conduct the heat in the axial interior of the winding to the two ends. The two ends of the heat pipe are then in direct contact with the oil, thereby achieving rapid heat dissipation; the heat dissipation path is increased, and the phenomenon of local high temperature in the axial middle area of ​​the motor stator winding is significantly alleviated, thereby reducing the motor winding temperature, achieving a significant reduction in motor temperature, enhancing motor temperature uniformity, and increasing the motor safe operation overload multiple.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for designing a heat dissipation structure of a phase change heat transfer motor stator, characterized in that the steps include: S1. Obtain the geometric parameters of the copper wire winding and stator core in the motor; S2. Customize and process the slots in the radial direction of the copper wire winding that contact the stator core according to the geometric parameters of the stator core; S3. Designing a flattened phase change heat transfer device and layout parameters based on the geometric parameters obtained in S1; S4. Pre-process the flattened phase change heat transfer device according to geometric parameters and layout parameters, and then pre-fix it, installing the flattened phase change heat transfer device in a slot radially inside the copper wire winding that contacts the stator core; S5. After being fixed, the flattened phase-change heat transfer device is heated and pressed with a mold to expand the flattened phase-change heat transfer device toward the circumference of the stator core, so that the flattened phase-change heat transfer device fits tightly against the stator core and does not extend beyond the inner radius of the stator core. A heat dissipation structure employing a method for designing a heat dissipation structure of a phase change heat transfer motor stator comprises: a stator core, a copper wire winding, and a flattened phase change heat transfer device, wherein the copper wire winding is arranged inside the stator core, and the flattened phase change heat transfer device is arranged in a slot radially inside the copper wire winding and in contact with the stator core; The end of the flattened phase change heat transfer element extends axially out of the stator core and is in direct contact with the cooling oil; The flattened phase-change heat transfer device comprises an evaporation section and a condensation section, wherein the condensation sections are located on both sides of the flattened phase-change heat transfer device, and the evaporation section is located between the two condensation sections; The length of the flattened phase change heat transfer device is 110%-120% of the axial length of the stator core, its width is 85%-95% of the width of the slot in the radial inner part of the winding that contacts the stator core, and its height is 75%-85% of the height of the slot in the radial inner part of the winding that contacts the stator core.

2. The method for designing a heat dissipation structure of a phase change heat transfer motor stator according to claim 1, characterized in that: The geometric parameters of the copper wire winding and the stator core in S1 include: the cross-sectional diameter, cross-sectional shape, thickness of the copper wire winding, the spacing between the copper wire winding and the rotor, and the cross-sectional shape and area of ​​the slot in the radial inner portion of the winding that contacts the stator core.

3. The method for designing a heat dissipation structure of a phase change heat transfer motor stator according to claim 1, characterized in that: The slot in the radial direction inside the copper wire winding in S2 that contacts the stator core includes a slot height and a slot depth.

4. The method for designing a heat dissipation structure of a phase change heat transfer motor stator according to claim 1, characterized in that: The S3 design of the flattened phase change heat transfer device includes the design of a linear flattened phase change heat transfer device and a bent flattened phase change heat transfer device. The design parameters of the linear flattened phase change heat transfer device include the length and diameter before flattening and the width and height after flattening. The design parameters of the bent flattened phase change heat transfer device include the bending angle, thickness, cross-sectional size and cross-sectional shape.

5. The method for designing a heat dissipation structure of a phase change heat transfer motor stator according to claim 1, characterized in that: The arrangement parameters of the flattened phase change heat transfer devices in S3 include the number, arrangement positions and arrangement angles of the flattened phase change heat transfer devices.

6. The method for designing a heat dissipation structure of a phase change heat transfer motor stator according to claim 1, characterized in that: The contact areas between the flattened phase-change heat transfer component and the stator core and the copper wire winding are filled with a thermally conductive interface material.

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