Phase change heat transfer motor stator heat dissipation structure and design method

Abstract

The invention discloses a phase change heat transfer motor stator heat dissipation structure and a design method, and belongs to the technical field of motor heat management, the structure comprises a stator iron core, a copper wire winding and a flattening type phase change heat transfer device, the copper wire winding is arranged on the inner side of the stator iron core, and the flattening type phase change heat transfer device is arranged on the outer side of the stator iron core; the flattening type phase change heat transfer device is arranged in a groove, in contact with the stator core, in the radial interior of the copper wire winding. The invention further discloses a design method of the heat dissipation structure. By adopting the heat dissipation structure and the design method, the thermal control technology of the motor stator winding is researched and developed based on the phase change heat transfer device, and the purposes of greatly reducing the peak temperature of the motor, enhancing the temperature uniformity of the motor and realizing high-overload-multiple safe operation are achieved.

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. Background Art

[0002] With the rapid development of new energy vehicles, the performance requirements for motors as drives are getting higher and higher. Although the temperature of existing oil-cooled motors has been improved compared to water-cooled motors, there is still a high temperature problem inside. When the automotive motor is running under high-power extreme conditions such as starting, climbing, accelerating, and emergency braking, the temperature difference inside the motor will be as high as 70°C or more, and may even cause 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 safe operation at high overload multiples.

[0005] To achieve the above object, the present invention provides a method for designing a heat dissipation structure of a phase change heat transfer motor stator, the steps comprising: S1, obtaining 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 are in contact with the stator core according to the geometric parameters of the stator core; S3, designing a flattened phase change heat transfer device and layout parameters according to the geometric parameters obtained in S1; S4, pre-processing the flattened phase change heat transfer device according to the geometric parameters and the layout parameters, and then pre-fixing it, and installing the flattened phase change heat transfer device in the slot in the radial inner part of 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 with the stator core and does not exceed the inner radius of the stator core.

[0006] 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 radially inside the winding that contacts the stator core.

[0007] Preferably, the slot radially inside the copper wire winding in S2 that contacts the stator core includes a slot height and a slot depth.

[0008] 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, and the design parameters of the bent flattened phase change heat transfer device include the bending angle, thickness, cross-sectional size and cross-sectional shape.

[0009] Preferably, the arrangement parameters of the flattened phase change heat transfer devices in S3 include the arrangement quantity, arrangement position and arrangement angle of the flattened phase change heat transfer devices.

[0010] The present invention also provides a phase change heat transfer motor stator heat dissipation structure, comprising 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.

[0011] Preferably, the end of the flattened phase change heat transfer device extends axially out of the stator core and is in direct contact with the cooling oil.

[0012] 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.

[0013] 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.

[0014] Preferably, the contact parts between the flattened phase change heat transfer device and the stator core and the copper wire winding are filled with a thermally conductive interface material.

[0015] 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: (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. The ultra-high thermal conductivity of the flattened phase change heat transfer device allows the heat in the axial direction of the winding to be quickly transferred to both 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, the 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 at high overload multiples.

[0016] (2) Filling the cavity between the rotor and stator windings with low-cost and more efficient phase change heat transfer devices enhances heat conduction and reduces the cost of motor cooling.

[0017] (3) The motor structure is optimized based on phase change heat transfer devices that can be customized and produced industrially. The implementation method is simple, practical and low-cost.

[0018] (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.

[0019] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of a heat dissipation structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the stator core structure of an embodiment of the present invention; Figure 3 It is a schematic diagram of assembling a flattened phase change heat transfer device according to an embodiment of the present invention; Figure 4 This is a schematic diagram of a linear flattened phase change heat transfer device according to an embodiment of the present invention; Reference numerals 1. Stator core; 2. Copper wire winding; 3. Flattened phase change heat transfer device; 31. Evaporation section; 32. Condensation section. DETAILED DESCRIPTION

[0021] 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, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here 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 in 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.

[0022] Example Reference Figure 1-4The present invention provides a phase change heat transfer motor stator heat dissipation structure, based on a phase change heat transfer device, including a stator core 1, a copper wire winding 2 and a flattened phase change heat transfer device 3, wherein the copper wire winding 2 is arranged inside the stator core 1, and the flattened phase change heat transfer device 3 is arranged in a slot radially inside the copper wire winding 2 and in contact with the stator core 1. The materials of the flattened phase change heat transfer device 3 include but are not limited to copper, aluminum and its alloys, stainless steel and other materials.

[0023] The end of the flattened phase-change heat transfer device 3 extends axially out of the stator core 1 and is in direct contact with the cooling oil. The extension length 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 is flush with the other end, and the two ends extend at different lengths.

[0024] The flattened phase-change heat transfer device 3 includes a straight-line flattened phase-change heat transfer device and a bent flattened phase-change heat transfer device. The bent portion of the bent flattened phase-change heat transfer device is the portion extending out of the stator core 1. The bent flattened heat pipe includes but is not limited to one end bent, one end not bent, both ends bent, and different bending lengths.

[0025] The flattened phase-change heat transfer device 3 comprises an evaporation section 31 and a condensation section 32 . The condensation sections 32 are located at both sides of the flattened phase-change heat transfer device 3 , and the evaporation section 31 is located between the two condensation sections 32 .

[0026] 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.

[0027] When installing the heat dissipation structure, first install the copper wire winding 2 inside the stator core 1. After installation, spray the insulating paint, and then place the flattened phase change heat transfer device 3 in the slot in contact with the stator core 1 in the radial inner part of the stator core 1 winding. The contact part between the flattened phase change heat transfer device 3 and the stator core 1 and the copper wire winding 2 is filled with thermal interface material, and the relative position of the flattened phase change heat transfer device 3 is fixed by insulating waterproof glue. Thermal interface materials include thermal adhesive, thermal double-sided adhesive, thermal mud, thermal paste and other thermal interface materials that can reduce thermal resistance.

[0028] The present invention also provides a method for designing a heat dissipation structure of a phase change heat transfer motor stator, the steps comprising: S1. Obtain geometric parameters of the copper wire winding 2 and the stator core 1 in the motor.

[0029] 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.

[0030] 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.

[0031] There are two ways to customize the slots of the copper wire winding 2 in radial direction in contact with the stator core 1, and the two ways are as follows: Method 1: When manufacturing the silicon steel sheets of the stator core 1, the slots in the radial direction of the winding that are in contact with the stator core 1 are processed to a corresponding width by stamping at one time so as to accommodate the flattened phase change heat transfer device.

[0032] Method 2: The slots of the stator core 1 are widened for a second time, and the slots of the stator core 1 in contact with the stator core 1 in the radial direction of the winding are widened to a corresponding width so as to place the flattened phase change heat transfer device. The second widening process of the slots of the stator core includes but is not limited to wire cutting, laser cutting, water cutting, plasma cutting and other methods.

[0033] S3. Design a flattened phase change heat transfer device 3 and layout parameters according to the geometric parameters obtained in S1.

[0034] Designing a flattened phase change heat transfer device 3 includes designing a straight flattened phase change heat transfer device and a bent flattened phase change heat transfer device. The design parameters of the straight flattened phase change heat transfer device include the length and diameter before flattening and the width and height after flattening, and the design parameters of the bent flattened phase change heat transfer device include the bending angle, thickness, cross-sectional size and cross-sectional shape.

[0035] The arrangement parameters of the flattened phase change heat transfer devices 3 include the arrangement quantity, arrangement position and arrangement angle of the flattened phase change heat transfer devices.

[0036] S4. Pre-process the flattened phase change heat transfer device 3 according to the geometric parameters and layout parameters, and then pre-fix it, and install the flattened phase change heat transfer device 3 in the slot in the radial inner part of the copper wire winding 2 that contacts the stator core 1. Tools for fixing the relative position of the flattened phase change heat transfer device include waterproof insulating glue, limiters and other tools.

[0037] 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 in the circumferential direction of the stator core instead of in the radial direction, so that the flattened phase-change heat transfer device 3 fits tightly with the stator core 1 and the flattened phase-change heat transfer device 3 does not exceed the inner radius of the stator core.

[0038] Specifically, the bent and flattened phase change heat transfer device is heated to 180-200° C., and then cooled through thermal expansion, so that the bent and flattened heat pipe has an interference fit with the groove in the width direction.

[0039] Therefore, the present invention adopts the above-mentioned phase change heat transfer motor stator heat dissipation structure and design method, and 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 used to quickly conduct the heat inside the winding axial direction to both ends, and the two ends of the heat pipe are 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, the motor winding temperature is reduced, and the motor temperature is greatly reduced, the motor temperature is enhanced, and the motor safe operation overload multiple is increased.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. 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 solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution 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, obtaining 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 are in contact with the stator core according to the geometric parameters of the stator core; S3, designing a flattened phase change heat transfer device and layout parameters according to the geometric parameters obtained in S1; S4, pre-processing the flattened phase change heat transfer device according to the geometric parameters and the layout parameters, and then pre-fixing it, and installing the flattened phase change heat transfer device in the slot in the radial inner part of 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 with the stator core and does not exceed the inner radius of the stator core.

2. A 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 part 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 radially inner part of 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 designed 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.

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 arrangement quantity, arrangement position and arrangement angle of the flattened phase change heat transfer devices.

6. A phase change heat transfer motor stator heat dissipation structure, using a phase change heat transfer motor stator heat dissipation structure design method as claimed in any one of claims 1 to 5, characterized in that: The invention comprises a stator core, a copper wire winding and a flattened phase-change heat transfer device. 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.

7. A phase change heat transfer motor stator heat dissipation structure according to claim 6, characterized in that: The end of the flattened phase-change heat transfer device extends out of the stator core along the axial direction and is in direct contact with the cooling oil.

8. The phase change heat transfer motor stator heat dissipation structure according to claim 6, characterized in that: 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.

9. The phase change heat transfer motor stator heat dissipation structure according to claim 6, characterized in that: 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.

10. The phase change heat transfer motor stator heat dissipation structure according to claim 6, characterized in that: The contact parts between the flattened phase change heat transfer device and the stator core and the copper wire winding are filled with a thermally conductive interface material.

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