Composite heat dissipation structure and axial flux motor

Abstract

The invention relates to the technical field of motors, and discloses a composite heat dissipation structure and an axial flux motor, and the composite heat dissipation structure comprises a cooling flow channel which is arranged in a housing; one end of each heat transfer piece is clamped between the layered stator assemblies, and the other end of each heat transfer piece is inserted into the cooling flow channel; the closed cavity is arranged between the stator assembly and the casing, and the closed cavity is filled with a solid-liquid phase change material; the composite heat dissipation structure transmits heat of the stator assembly into the cooling flow channel through the heat transfer piece and the solid-liquid phase change material together so as to dissipate heat of the stator assembly. According to the composite heat dissipation structure, heat dissipation is conducted through the cooling flow channel in the machine shell, heat dissipation is conducted on the stator winding through the heat transfer piece, phase change heat storage and conduction are conducted on heat generated by the stator winding through the solid-liquid phase change material in the closed cavity, and a triple heat dissipation path of machine shell-heat transfer piece-solid-liquid phase change material is formed; long-time temperature rise and transient temperature rise of the motor are obviously reduced, the performance of the motor is improved, and the service life of the motor is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and particularly to a composite heat dissipation structure and an axial flux motor. Background Art

[0002] Axial flux motors have the advantages of compact axial dimensions and large output torque, and are widely used in new energy vehicles, aerospace, ship propulsion, robots, and wind power generation, etc., which require high torque density and compact axial space; they are particularly suitable for distributed drive electric vehicles with in-wheel direct drive. The air gap of the axial flux motor is planar, with a short axial length and a thin disc shape. Therefore, the axial flux motor is also called a disc motor.

[0003] Similar to ordinary motors, existing axial flux motors generally include a stator and a rotor, and windings are wound on the stator; however, since the windings of existing axial flux motors are located between the stator and the rotor, the structure is very compact, and the heat dissipation condition of the axial flux motor is extremely poor. When operating under high load, the axial flux motor is extremely prone to overheating, seriously affecting the performance and service life of the axial flux motor. Summary of the Invention

[0004] In view of this, the present invention provides a composite heat dissipation structure to solve the problems that the windings of existing axial flux motors are located between the stator and the rotor, the structure is very compact, the heat dissipation condition is extremely poor, and when operating under high load, the axial flux motor is extremely prone to overheating, seriously affecting the performance and service life of the axial flux motor.

[0005] In a first aspect, the present invention provides a composite heat dissipation structure, including:

[0006] A cooling channel, arranged inside the housing;

[0007] A plurality of heat transfer members, one end of which is clamped between the layered stator assemblies; the other ends of the plurality of heat transfer members are inserted into the cooling channel; the stator assembly is installed inside the housing;

[0008] A sealed cavity, arranged between the stator assembly and the housing, and a solid-liquid phase change material is filled in the sealed cavity;

[0009] The composite heat dissipation structure is adapted to transfer the heat generated by the stator assembly to the cooling channel through the heat transfer member and the phase change heat storage of the solid-liquid phase change material, so as to dissipate heat from the stator assembly. Beneficial effects: By adopting the above technical solution, the present application not only dissipates heat through the cooling channel in the housing, but also dissipates heat from the stator winding through the heat transfer member, and also stores and conducts the heat generated by the stator winding through the solid-liquid phase change material in the sealed cavity, forming a triple heat dissipation path of "housing - heat transfer member - solid-liquid phase change material". When the composite heat dissipation structure is used in a motor, the long-term temperature rise and transient temperature rise of the motor are significantly reduced, the performance of the motor is improved, and the service life of the motor is extended. Moreover, while improving the heat dissipation conditions, the heat transfer member does not occupy the axial air gap space of the motor, avoiding an increase in the axial equivalent air gap length.

[0010] Optionally, the stator assembly is fixedly installed in the housing through a bracket; non-metallic heat-conducting powder is mixed in the solid-liquid phase change material.

[0011] Optionally, a baffle is hermetically connected between the stator assembly and the housing, and the stator assembly, the housing and the baffle jointly enclose the sealed cavity.

[0012] Optionally, the stator assembly includes:

[0013] A plurality of stator teeth arranged in a surrounding manner;

[0014] A stator winding wound around the stator teeth, and the stator winding is divided into multiple layers in the circumferential direction; one ends of a plurality of heat transfer members are clamped between adjacent layers of the stator winding.

[0015] Optionally, the stator winding is an integral-slot distributed winding or a fractional-slot concentrated winding.

[0016] Optionally, one end of the heat transfer member in contact with the stator winding is the hot end, and one end of the heat transfer member inserted into the cooling channel is the cold end;

[0017] Both the hot end and the cold end are flattened; the flat surface of the heat transfer member is in contact with the stator winding; the heat transfer member is a heat pipe. Beneficial effects: By adopting the above technical solution, through the flat heat transfer member, the contact area between the heat transfer member and the winding is increased, and the heat dissipation efficiency is improved.

[0018] Optionally, the bracket is provided with a supporting portion, and the supporting portion is adapted to fix the stator teeth.

[0019] Optionally, the bracket is provided with a supporting portion, and a non-magnetic gasket is further provided between the supporting portion and the stator teeth, and the non-magnetic gasket is adapted to fix the stator teeth.

[0020] In a second aspect, the present invention further provides an axial-flux motor, including: the composite heat dissipation structure described above.

[0021] Optionally, it further includes:

[0022] A rotor assembly, which consists of a rotating shaft and two rotors fixed on the rotating shaft;

[0023] A stator assembly, which is clamped between the two rotors;

[0024] A housing, in which the two rotors and the stator assembly are arranged. The rotating shaft penetrates through the housing and the stator assembly, and the rotating shaft is rotatably connected to the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Figure 1 It is a schematic cross-sectional structure diagram of the composite heat dissipation structure provided in Embodiment 1 of the present invention;

[0027] Figure 2 It is a schematic three-dimensional structure diagram of the stator assembly provided in Embodiment 1 of the present invention;

[0028] Figure 3 It is a schematic three-dimensional structure diagram of the stator teeth provided in Embodiment 1 of the present invention;

[0029] Figure 4 It is a schematic partial three-dimensional structure diagram of the composite heat dissipation structure provided in Embodiment 1 of the present invention Figure 1 ;

[0030] Figure 5 It is a schematic three-dimensional structure diagram of the bracket provided in Embodiment 1 of the present invention;

[0031] Figure 6 It is a schematic partial three-dimensional structure diagram of the composite heat dissipation structure provided in Embodiment 1 of the present invention Figure 2 ;

[0032] Figure 7 It is a schematic three-dimensional structure diagram of the stator assembly provided in Embodiment 2 of the present invention;

[0033] Figure 8 It is a schematic partial three-dimensional structure diagram of the composite heat dissipation structure provided in Embodiment 2 of the present invention;

[0034] Figure 9 It is a schematic three-dimensional structure diagram of the heat transfer member provided in Embodiment 3 of the present invention;

[0035] Figure 10 This is a partial three-dimensional structural schematic diagram of the composite heat dissipation structure provided in the fourth embodiment of the present invention.

[0036] Explanation of reference numerals:

[0037] 1. Housing; 2. Stator assembly; 3. Bracket; 4. Heat transfer member; 5. Solid-liquid phase change material; 6. Baffle; 7. Rotor assembly; 8. Retaining ring; 9. Cooling channel; 10. Stator tooth; 11. Stator winding; 12. Support portion; 13. Non-magnetic gasket; 14. Cold end; 15. Hot end. Specific embodiments

[0038] To make the objectives, 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 with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] Embodiment 1

[0040] As Figures 1 to 6 shown, a specific embodiment of the composite heat dissipation structure includes: a cooling channel 9, a plurality of heat transfer members 4, and a sealed cavity. The composite heat dissipation structure is provided on a motor.

[0041] As Figure 1 shown, the cooling channel 9 is provided in the housing 1. One end of a plurality of heat transfer members 4 is clamped between the layered stator assemblies 2; the other ends of the plurality of heat transfer members 4 are inserted into the cooling channel 9; the stator assembly 2 is installed in the housing 1. The sealed cavity is provided between the stator assembly 2 and the housing 1, and a solid-liquid phase change material 5 is filled in the sealed cavity. The composite heat dissipation structure is adapted to transfer the heat generated by the stator assembly 2 to the cooling channel 9 through the heat transfer of the heat transfer member 4 and the phase change heat storage of the solid-liquid phase change material 5 to dissipate heat from the stator assembly 2. The heat transfer member 4 is a high thermal conductivity component made of a high thermal conductivity material. When the other end of the heat transfer member 4 is inserted into the cooling channel 9, the other end of the heat transfer member 4 can be connected to the housing 1 by sealed welding, or the gap between the heat transfer member 4 and the housing 1 can be sealed with a sealing ring or sealant to fix the other end of the heat transfer member 4. A sealing arrangement is also adopted at the part where the heat transfer member 4 passes through the sealed cavity.

[0042] Specifically, the stator assembly 2 is fixedly installed in the housing 1 through the bracket 3; the bracket 3 and the housing 1 can be fixedly connected by interference fit, or fixed by a retaining ring 8 along the axial direction of the motor, or fixed by screws along the axial direction of the motor, or fixed by welding. Non-metallic heat-conducting powder is mixed in the solid-liquid phase change material 5, and the non-metallic heat-conducting powder is a high heat-conducting material. The solid-liquid phase change material 5 can store heat through phase change to reduce the temperature rise of the motor under peak torque conditions. A baffle 6 is hermetically connected between the stator assembly 2 and the housing 1, and the stator assembly 2, the housing 1 and the baffle 6 jointly enclose the closed cavity. There are two baffles 6, which are respectively arranged at the front end and the rear end of the stator assembly 2 along the axial direction of the motor.

[0043] As Figures 2 to 4 shown, the stator assembly 2 includes: a plurality of stator teeth 10 arranged in a surrounding manner and a stator winding 11. The stator winding 11 is wound around the stator teeth 10, and the stator winding 11 is divided into multiple layers in the circumferential direction; one end of a plurality of heat transfer members 4 is clamped between adjacent layers of the stator winding 11. The stator winding 11 is an integral-slot distributed winding. One end of the heat transfer member 4 in contact with the stator winding 11 is the hot end 15, and one end of the heat transfer member 4 inserted into the cooling channel 9 is the cold end 14; the heat transfer member 4 is a heat pipe. The hot end 15 is arranged perpendicular to the axial direction of the motor, rather than parallel to the axial direction of the motor, so that the heat transfer member 4 does not prevent the stator winding 11 from winding across the stator teeth 10. The stator assembly 2 can be a yoke structure or a non-yoke structure; preferably it is a non-yoke structure. The stator teeth 10 are made by laminating soft magnetic material thin sheets, and the soft magnetic material thin sheets are parallel to the axial direction of the motor; the soft magnetic material thin sheets are preferably grain-oriented silicon steel sheets. Among them, Figure 3 and Figure 4 the arrows in indicate the axial direction of the motor.

[0044] As Figure 5 and Figure 6 shown, the bracket 3 is provided with a support portion 12, and the support portion 12 is adapted to fix the stator teeth 10. Specifically, the annular body of the bracket 3 is connected to a plurality of the support portions 12 arranged on the outer periphery of the annular body. The annular body is located inside a plurality of surrounding stator teeth 10, and two support portions 12 arranged at intervals are opposite to each other up and down, and adjacent support portions 12 are in contact with the tooth tips of the stator teeth 10 to clamp and fix one stator tooth 10 along the axial direction of the motor.

[0045] The composite heat dissipation structure described in this application has three heat dissipation paths for the motor. The first heat dissipation path is as follows: a cooling flow channel 9 is provided inside the housing 1, which can take away the heat from the inner wall of the housing 1; the second heat dissipation path is: the heat transfer member 4 conducts the heat of the stator winding 11 into the cooling flow channel 9; the third heat dissipation path is: the solid-liquid phase change material 5, and high thermal conductivity non-metallic powder is doped in the solid-liquid phase change material 5, and the heat of the stator winding 11 is stored and transferred to the cooling flow channel 9 of the housing 1 through the solid-liquid phase change material 5. The solid-liquid phase change material 5 described in this application is not a conventional potting material and is sealed by the housing 1 and the baffles 6 located in front of and behind the bracket 3; the solid-liquid phase change material 5 can store heat through phase change and significantly reduce the temperature rise of the motor under the condition of instantaneous large current.

[0046] Reference Figure 1 As shown, the present invention also provides an axial flux motor, including: the composite heat dissipation structure, a rotor assembly 7, a stator assembly 2, and a housing 1.

[0047] The rotor assembly 7 is composed of a rotating shaft and two rotors fixed on the rotating shaft. The stator assembly 2 is sandwiched between the two rotors. That is, in the axial direction of the axial flux motor, a sandwich structure with the stator assembly 2 in the middle and rotors on both sides is adopted, and the assembly process of the axial flux motor follows the mature assembly technology of the axial flux motor.

[0048] Both of the two rotors and the stator assembly 2 are arranged inside the housing 1, the rotating shaft penetrates through the housing 1 and the stator assembly 2, and the rotating shaft is rotatably connected to the housing 1.

[0049] Embodiment 2

[0050] As Figure 7 and Figure 8 shown, the stator winding 11 is a fractional-slot concentrated winding; both the hot end 15 and the cold end 14 are flattened; the flat surface of the heat transfer member 4 is in contact with the stator winding 11; the flat surface of the cold end 14 is perpendicular to the flat surface of the hot end 15, and the flat surface of the hot end 15 is perpendicular to the axial direction of the motor, rather than parallel to the axial direction of the motor, so that the heat transfer member 4 does not prevent the stator winding 11 from winding across the stator teeth 10. The heat transfer member 4 can be a superconducting flat heat pipe. While improving the heat dissipation condition of the stator winding 11, the superconducting flat heat pipe does not occupy the axial air gap space of the motor and avoids increasing the axial equivalent air gap length. Among them, Figure 8 the arrow in represents the axial direction of the motor. The rest of the technical solutions are the same as those in Embodiment 1.

[0051] Embodiment 3

[0052] As Figure 9 shown, for the heat transfer member 4, the flat surface of the cold end 14 is parallel to the flat surface of the hot end 15. Among them, Figure 9The arrow in it indicates the axial direction of the motor. The rest is the same as the technical solution of the second embodiment.

[0053] Embodiment 4

[0054] As Figure 10 shown, a non-magnetic gasket 13 is further provided between the support portion 12 and the stator tooth 10, and the non-magnetic gasket 13 is adapted to fix the stator tooth 10; the non-magnetic gasket 13 is a high-strength gasket. The rest is the same as the technical solutions of Embodiment 1, Embodiment 2 or Embodiment 3.

[0055] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A composite heat dissipation structure, characterized in that, Comprising: A cooling channel (9) provided within a housing (1); A plurality of heat transfer members (4), one end of which is clamped between stator assemblies (2) arranged in layers; the other ends of the plurality of heat transfer members (4) are inserted into the cooling channel (9); the stator assemblies (2) are installed within the housing (1); A sealed cavity provided between the stator assembly (2) and the housing (1), and a solid-liquid phase change material (5) is filled within the sealed cavity; The composite heat dissipation structure is adapted to transfer the heat generated by the stator assembly (2) to the inside of the cooling channel (9) through the heat transfer of the heat transfer members (4) and the phase change heat storage of the solid-liquid phase change material (5) to dissipate heat from the stator assembly (2).

2. The composite heat dissipation structure according to claim 1, wherein The stator assembly (2) is fixedly installed within the housing (1) through a bracket (3); a non-metallic heat conductive powder is incorporated within the solid-liquid phase change material (5).

3. The composite heat dissipation structure according to claim 2, characterized in that, A baffle (6) is sealingly connected between the stator assembly (2) and the housing (1), and the stator assembly (2), the housing (1) and the baffle (6) together enclose the sealed cavity.

4. The composite heat dissipation structure according to claim 2 or 3, characterized in that, The stator assembly (2) includes: A plurality of stator teeth (10) arranged in a surrounding manner; A stator winding (11) wound around the stator teeth (10), and the stator winding (11) is divided into multiple layers in the circumferential direction; one ends of the plurality of heat transfer members (4) are clamped between adjacent layers of the stator windings (11).

5. The composite heat dissipation structure according to claim 4, wherein, The stator winding (11) is an integral slot distributed winding or a fractional slot concentrated winding.

6. The composite heat dissipation structure according to claim 5, characterized in that, One end of the heat transfer member (4) in contact with the stator winding (11) is a hot end (15), and one end of the heat transfer member (4) inserted into the cooling channel (9) is a cold end (14); Both the hot end (15) and the cold end (14) are flattened; the flat surface of the heat transfer member (4) is in contact with the stator winding (11); the heat transfer member (4) is a heat pipe.

7. The composite heat dissipation structure according to claim 4, wherein The bracket (3) is provided with a support portion (12), and the support portion (12) is adapted to fix the stator teeth (10).

8. The composite heat dissipation structure according to claim 4, wherein The bracket (3) is provided with a support portion (12), and a non-magnetic gasket (13) is further provided between the support portion (12) and the stator teeth (10), and the non-magnetic gasket (13) is adapted to fix the stator teeth (10).

9. An axial flux motor, characterized in that, Comprising: The composite heat dissipation structure according to any one of claims 1-8.

10. The axial flux motor according to claim 9, wherein, Further comprising: A rotor assembly (7) composed of a rotating shaft and two rotors fixed to the rotating shaft; A stator assembly (2) sandwiched between the two rotors; A housing (1), both the two rotors and the stator assembly (2) are provided within the housing (1), the rotating shaft penetrates through the housing (1) and the stator assembly (2), and the rotating shaft is rotatably connected to the housing (1).

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