An outer rotor motor with integrated thermal management system

Abstract

The application discloses an outer rotor motor of an integrated thermal management system applied to the field of motors, and through the cooperative design of a hollow rotating shaft, a radial cooling member and an axial air duct, when it is detected that cooling is needed, two cooling paths of the radial and axial directions can be simultaneously opened, so that cooling air flow can more fully exchange heat with the surfaces of stator members and rotor members, the thermal management efficiency is comprehensively improved, in addition, in the initial stage of cooling, the temperature of the gas is high, the blocking ring is kept contracted, a large amount of air flow is allowed to pass through to rapidly dissipate heat, as the heat dissipation proceeds, the temperature of the gas decreases, the blocking ring gradually expands, part of the air flow channels are closed, the residence time of the cooling air in the inner region of the stator winding is prolonged, the heat exchange contact of the air flow and the deep winding is promoted, after the gas is heated, the blocking ring is contracted again to release the air flow, the penetration ability of the air flow to the hidden parts is strengthened, and the overall heat dissipation uniformity is improved.

Description

Technical Field

[0001] This invention relates to the field of electric motors, and in particular to an external rotor motor with an integrated thermal management system. Background Technology

[0002] Thermal management of external rotor motors directly determines their lifespan and reliability. Because the windings and controller are located in the center, the heat dissipation space is limited. If heat cannot be dissipated in time, it will accelerate insulation aging, cause permanent magnet demagnetization, and even burn out the controller. Effective thermal management can reduce temperature rise, improve overload capacity, and ensure that the motor can continuously output rated power in a compact environment. It is the core guarantee for balancing miniaturization and high performance.

[0003] The prior art CN202411155255.5 discloses a forced air-cooled external rotor axial flux motor. When the external rotor of this invention rotates, it can form a centrifugal fan structure with the cooperation of heat dissipation fins and air guide shroud. In turn, air pressure is generated when the rotor shell rotates, which can dissipate heat to achieve heat dissipation of the stator and avoid poor heat dissipation of the stator.

[0004] The prior art CN202511037413.1 discloses an external rotor permanent magnet motor, which achieves air cooling through the self-rotation of the external rotor structure and combines it with stable water cooling of the internal stator structure, thus greatly improving the heat dissipation effect of the motor.

[0005] In the aforementioned prior art, external rotor motors all use the air cooling effect generated by the rotation of the rotor driving the fan blades to assist in the cooling of the motor. However, in actual operation, when a heavy, low-speed object is connected to the output end of the external rotor motor, the speed of the driven fan is also at a low speed. The air cooling effect that the external rotor and the fan blades on its surface can provide during operation is basically insufficient to achieve air cooling. Under this premise, the installation of fan blades will increase unnecessary areas inside the motor, which is not conducive to achieving miniaturization and weight reduction of the motor. Furthermore, since the stator is an integrated design, it is not conducive to achieving cooling of the inside of the stator. Summary of the Invention

[0006] The core of this invention lies in solving the problems in existing technologies where the rotational speed of the inner rotor components in an external rotor motor cannot provide adequate air cooling, and the inner side of the stator components cannot dissipate heat, through the coordinated design of a hollow rotating shaft, radial cooling components, and axial air ducts. Simultaneously, by utilizing sealing rings, sufficient heat exchange can be achieved for structures such as the windings on the inner side of the stator components, improving the overall uniformity of heat dissipation.

[0007] To solve the above problems, the present invention adopts the following technical solution.

[0008] An external rotor motor with an integrated thermal management system includes a housing, with a front cover and a rear cover installed at both ends of the housing. A rotor component is installed inside the housing, and multiple stator components are installed inside the rotor component. A hollow rotating shaft penetrating the interior of the front cover is installed inside the stator component. An air supply pipe extending from the tail end to the interior of the hollow rotating shaft is installed through the interior of the rear cover. A hollow ring is fixedly sleeved on the surface of the hollow rotating shaft near the rear cover, and the hollow ring and the hollow rotating shaft are connected through an air inlet pipe. An air guide ring is installed through the surface of the hollow ring away from the rear cover, and the tail end of the air guide ring is in sealed contact with the surfaces of the rotor component and the stator component. Radial cooling components are installed through the hollow shaft surface at the position between the gaps between two adjacent stator components. Each radial cooling component includes two closed slots opened on the surface of the hollow shaft. Multiple fixed posts are fixedly installed on the inner wall of each closed slot. A central ring is fitted in the middle of the fixed post of each radial cooling component. Fitting grooves are opened on both sides of each central ring. Multiple spring components are installed on the inner wall of each closed slot. A movable sealing ring is connected to the tail end of each spring component inside the closed slot. A through pipe is installed through the inside of each closed slot.

[0009] Furthermore, one end surface of the rotor component is fixedly connected to the surface of the hollow shaft, and the other end of the rotor component is rotatably connected to the outer casing. The stator component and the hollow shaft are rotatably connected through bushings, and the two ends of the hollow shaft are rotatably connected to the front cover and the rear cover through bushings, respectively.

[0010] Furthermore, an exhaust pipe and a boss are installed inside the hollow shaft, and the diameter of the surface of the boss near the front cover is smaller than the diameter of the surface of the boss away from the front cover. The exhaust pipe is located in the middle between the end of the stator component near the front cover and the end of the rotor component near the front cover.

[0011] Furthermore, the movable sealing ring, the fitting groove, and the closed groove have the same cross-sectional area, and the depth of the closed groove is greater than the thickness of the movable sealing ring. The cross-section of the central ring is the same as that of the hollow rotating shaft, and a displacement sensor is installed inside the movable sealing ring.

[0012] Furthermore, the horizontal distance between the side surface of the fitting groove near the centering ring and the side surface of the closing groove near the centering ring is less than the thickness of the movable sealing ring.

[0013] Furthermore, the end of the air guide ring is fixedly sealed to the surface of the rotor component, and the end of the air guide ring is rotated sealed to the surface of the stator component. One-way valves are installed inside the air intake pipe and the exhaust pipe, and the surface of the air supply pipe is connected to a branch pipe that is connected to the through pipe and a tail pipe that supplies air to the hollow shaft.

[0014] Optionally, the outer surface of each centering ring is fixedly connected to a sealing ring made of shape memory alloy material, and the cross-sectional width of the sealing ring in the initial state is greater than the horizontal distance between two adjacent stator components.

[0015] Furthermore, each sealing ring is in sliding contact with the outer surfaces of the two adjacent stator components, and an elastic pad is installed on the inner surface of the sealing ring.

[0016] Compared with the prior art, the advantages of this invention are: (1) This solution uses the coordinated design of hollow shaft, radial cooling components and axial air duct. When cooling is required, both radial and axial cooling paths can be opened at the same time. The annular airflow formed by the radial cooling components can evenly cover the gap between multiple stator segments, while the axial airflow can effectively pass through the air gap between the stator and rotor. This three-dimensional heat dissipation method increases the heat exchange area, allowing the cooling airflow to exchange heat more fully with the surface of the stator and rotor components, which helps to maintain the stability of the motor's operating temperature and comprehensively improve the thermal management efficiency.

[0017] (2) In the initial stage of cooling, the gas temperature is high and the sealing ring remains contracted, allowing a large amount of airflow to pass through for rapid heat dissipation. As heat dissipation proceeds, the gas temperature drops and the sealing ring gradually extends, partially closing the airflow channel. This prolongs the residence time of the cooling air in the inner area of ​​the stator winding, promoting heat exchange contact between the airflow and the deep winding. After the gas is heated, the sealing ring contracts again to release the airflow, enhancing the airflow's penetration ability into concealed parts and improving the overall heat dissipation uniformity. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the internal structure of the hollow rotating shaft of the present invention; Figure 2 For the present invention Figure 1 Enlarged diagram of point A in the diagram; Figure 3 This is a schematic diagram of the overall appearance of the present invention; Figure 4 This is a schematic diagram showing the installation of the hollow ring, intake pipe, and radial cooling component of the present invention. Figure 5 This is a schematic diagram of the radial cooling component of the present invention; Figure 6 This is a partial structural schematic diagram of the radial cooling component of the present invention; Figure 7 This is a schematic diagram of the movable sealing ring after it detaches from the centering ring in the radial cooling component of the present invention; Figure 8 This is a schematic diagram of the gas path for ventilation inside the hollow rotating shaft of the present invention; Figure 9This is a schematic diagram of the installation structure of the sealing ring, stator, and rotor components of the present invention; Figure 10 This is a diagram showing the state of air-cooled gas briefly entering the stator component for heat exchange when the sealing ring of the present invention briefly blocks the radial channel.

[0019] Explanation of the labels in the diagram: 1. Outer shell; 2. Hollow shaft; 201. Exhaust pipe; 202. Boss; 3. Front cover; 31. Rear cover; 4. Rotor component; 5. Stator component; 6. Hollow ring; 7. Inlet pipe; 8. Air supply pipe; 9. Air guide ring; 10. Radial cooling component; 101. Centering ring; 102. Movable sealing ring; 103. Fixed column; 104. Sealing groove; 105. Spring component; 106. Fitting groove; 107. Through pipe; 81. Branch pipe; 82. Tail pipe; 11. Sealing ring. Detailed Implementation

[0020] The technical solutions will now be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention.

[0021] Example 1:

[0022] Please see Figures 1-6 An external rotor motor with an integrated thermal management system includes a housing 1. A front cover 3 and a rear cover 31 are respectively installed at both ends of the housing 1. A rotor 4 is installed inside the housing 1. A plurality of stator 5 are installed inside the rotor 4. A hollow shaft 2 penetrating the interior of the front cover 3 is installed inside the stator 5. An air supply pipe 8 extending to the interior of the hollow shaft 2 is installed through the interior of the rear cover 31. A hollow ring 6 is fixedly sleeved on the side surface of the hollow shaft 2 near the rear cover 31. The hollow ring 6 and the hollow shaft 2 are connected through an air inlet pipe 7. An air guide ring 9 is installed through the side surface of the hollow ring 6 away from the rear cover 31. The tail end of the air guide ring 9 is in sealed contact with the surfaces of the rotor 4 and the stator 5. Radial cooling elements 10 are installed through the hollow shaft 2 at the position between the gaps between two adjacent stator components 5. Each radial cooling element 10 includes two closed grooves 104 opened on the surface of the hollow shaft 2. Multiple fixing posts 103 are fixedly installed on the inner wall of each closed groove 104. A central ring 101 is fitted in the middle of the fixing post 103 of each radial cooling element 10. Fitting grooves 106 are opened on both sides of each central ring 101. Multiple springs 105 are installed on the inner wall of each closed groove 104. A movable sealing ring 102 is connected to the tail end of each spring 105 inside each closed groove 104. A through pipe 107 is installed through the inside of each closed groove 104.

[0023] Please see Figure 1One end surface of the rotor component 4 is fixedly connected to the surface of the hollow shaft 2, and the other end of the rotor component 4 is rotatably connected to the outer casing 1. The stator component 5 and the hollow shaft 2 are rotatably connected through bushings. The two ends of the hollow shaft 2 are rotatably connected to the front cover 3 and the rear cover 31 through bushings, respectively.

[0024] Please see Figure 1 , Figure 2 and Figure 4 The hollow rotating shaft 2 is equipped with an exhaust pipe 201 and a boss 202. The diameter of the side surface of the boss 202 near the front cover 3 is smaller than the diameter of the side surface of the boss 202 away from the front cover 3. The exhaust pipe 201 is located in the middle between the end of the stator 5 near the front cover 3 and the end of the rotor 4 near the front cover 3.

[0025] Please see Figures 5-6 The movable sealing ring 102, the fitting groove 106 and the closing groove 104 have the same cross-sectional area, and the depth of the closing groove 104 is greater than the thickness of the movable sealing ring 102. The cross-section of the central ring 101 is the same as the cross-section of the hollow rotating shaft 2. A displacement sensor is installed inside the movable sealing ring 102.

[0026] Please see Figures 5-6 The horizontal distance between the side surface of the fitting groove 106 near the centering ring 101 and the side surface of the closing groove 104 near the centering ring 101 is less than the thickness of the movable sealing ring 102.

[0027] Please see Figure 1 The end of the air guide ring 9 is fixedly sealed to the surface of the rotor component 4, and the end of the air guide ring 9 is rotated sealed to the surface of the stator component 5. One-way valves are installed inside the air inlet pipe 7 and the exhaust pipe 201. The surface of the air supply pipe 8 is connected to the branch pipe 81 that is connected to the through pipe 107 and the tail pipe 82 that supplies air to the hollow rotating shaft 2.

[0028] Specifically, in this application, the stator component 5 has a multi-segment structure. For ease of explanation, the stator component 5 in this application has a three-segment structure. Two adjacent stator components 5 have a preset misalignment angle in the circumferential direction during installation, which is used to smooth the ripple of the motor output torque.

[0029] The motor is equipped with a temperature sensor to detect the temperature of the stator component 5. When cooling is required, the control valve on the surface of the through pipe 107 is first opened. Then, under the action of the spring component 105 (the spring component 105 can be replaced with a structure made of shape memory alloy, and the through pipe 107 is removed; the temperature rise causes the structure made of shape memory alloy to contract, which in turn causes the movable sealing ring 102 to contract and expose the corresponding radial channel), the movable sealing ring 102 moves away from the centering ring 101 and enters the interior of the sealing groove 104 (the displacement during this process is monitored by a displacement sensor, and the control valve on the surface of the through pipe 107 is closed after the movable sealing ring 102 enters the interior of the sealing groove 104), compressing the gas inside the original sealing groove 104, causing the movable sealing ring 102 to disengage from the interior of the fitting groove 106, thereby opening the radial cooling component 10 which was previously sealed (e.g., Figure 7 (as shown) Then, the air pump or other structure connected to the air supply pipe 8 is activated, allowing the air supply pipe 8 to deliver gas into the hollow shaft 2 through the tail pipe 82. The gas inside the hollow shaft 2 can then flow through the gap between the movable sealing ring 102 and the central ring 101 (hereinafter referred to as the radial channel) to the gap between adjacent stator components 5, forming a comprehensive radial air-cooling heat dissipation treatment. Compared to opening pipes for exhaust heat dissipation on the surface of the hollow shaft 2, the radial cooling component 10 of this application uses an annular exhaust treatment for radial heat dissipation, resulting in a more comprehensive air-cooling area and higher heat dissipation efficiency (e.g., ...). Figure 8 (as shown) After the hollow shaft 2 is ventilated, some of the gas enters the interior of the hollow ring 6 through the air inlet pipe 7, and is blown into the air gap between the stator component 5 and the rotor component 4 through the interior of the air guide ring 9, forming an axial heat dissipation operation (such as...). Figure 8 (as shown) In the axial and radial heat dissipation paths, the heat-exchanged gas is discharged unidirectionally through the exhaust pipe 201. Since the tail end of the exhaust pipe 201 is located on one side of the narrower surface of the boss 202, it can then be discharged into the motor through the hollow rotating shaft 2, thus achieving complete air cooling operation.

[0030] After cooling is complete, the control valve on the surface of the through pipe 107 remains open, the control valve on the surface of the tail pipe 82 closes, the air supply in the hollow shaft 2 stops, and the gas supplied by the air supply pipe 8 is transferred to the interior of the sealing groove 104 through the branch pipe 81, which increases the amount of gas in the sealing groove 104. The movable sealing ring 102 is forced to move closer to the fitting groove 106 until the movable sealing ring 102 closes the radial channel. At this time, after the displacement sensor detects that the displacement of the movable sealing ring 102 is sufficient to close the radial channel, the air supply pipe 8 stops supplying air, and the control valve on the surface of the through pipe 107 closes.

[0031] Example 2:

[0032] Please see Figure 9 Each centering ring 101 has a sealing ring 11 made of shape memory alloy material fixedly connected to its outer surface through an outer ring, and the cross-sectional width of the sealing ring 11 in the initial state is greater than the horizontal distance between two adjacent stator components 5.

[0033] Each sealing ring 11 is in sliding contact with the outer surfaces of the two adjacent stator components 5, and an elastic pad is installed on the inner surface of the sealing ring 11.

[0034] Specifically, in Embodiment 1, because the horizontal gap between two adjacent stator components 5 is small, the air-cooled gas released outward through the radial channel has a large wind speed after release and flows through the surface of the stator component 5 in a basically straight line. As a result, it is difficult to make heat exchange contact with the inner side of the winding on the surface of the stator component 5, which affects the heat exchange efficiency. To improve this situation, this embodiment is adopted.

[0035] During initial heat exchange, the released cooling gas reaches a relatively high temperature (around 50-60℃) at the sealing ring 11, causing the sealing ring 11 to contract under the influence of temperature, resulting in a large flow rate in the radial channel. As air cooling continues, the surface temperature of the stator component 5 decreases, and the temperature of the cooling gas gradually decreases as it reaches the sealing ring 11. At this point, the sealing ring 11 gradually elongates until it covers the cross-section of the shortened radial channel (i.e., the cross-sectional value of the sealing ring 11 is now greater than the horizontal distance between two adjacent stator components 5). This temporarily confines the cooling gas flowing out of the radial channel inside the sealing ring 11. Through the flow of air, heat exchange contact can be achieved within the windings of the stator component 5 (e.g., Figure 10 As shown in the figure, the gas temperature then rises, causing the sealing ring 11 to continue to retract, exposing the radial channel and releasing the heat-exchanged air-cooled gas.

[0036] The above description is merely a preferred embodiment of the present invention; it encompasses all the protection scope of the present invention. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in the present invention, based on the technical solutions and improved concepts of the present invention, should be covered within the protection scope of the present invention.

Claims

1. An external rotor motor with an integrated thermal management system, comprising a housing (1), wherein a front end cover (3) and a rear end cover (31) are respectively installed at both ends of the housing (1), characterized in that: A rotor component (4) is installed on the inner side of the outer casing (1). A plurality of stator components (5) are installed on the inner side of the rotor component (4). A hollow rotating shaft (2) that penetrates the interior of the front end cover (3) is installed on the inner side of the stator component (5). An air supply pipe (8) extending to the interior of the hollow rotating shaft (2) is installed through the interior of the rear end cover (31). A hollow ring (6) is fixedly sleeved on the side surface of the hollow rotating shaft (2) near the rear end cover (31). The hollow ring (6) and the hollow rotating shaft (2) are connected through the air inlet pipe (7). A guide ring (9) is installed through the side surface of the hollow ring (6) away from the rear end cover (31). The tail end of the guide ring (9) is in sealed contact with the surfaces of the rotor component (4) and the stator component (5). Radial cooling components (10) are installed through the hollow shaft (2) at the position between the gaps between two adjacent stator components (5). Each radial cooling component (10) includes two closed grooves (104) opened on the surface of the hollow shaft (2). Multiple fixing posts (103) are fixedly installed on the inner wall of each closed groove (104). A central ring (101) is fitted in the middle of the fixing post (103) of each radial cooling component (10). Fitting grooves (106) are opened on both sides of each central ring (101). Multiple spring components (105) are installed on the inner wall of each closed groove (104). A movable sealing ring (102) is connected to the tail end of the spring component (105) inside each closed groove (104). A through pipe (107) is installed through the inside of each closed groove (104).

2. The external rotor motor of the integrated thermal management system according to claim 1, characterized in that: One end surface of the rotor component (4) is fixedly connected to the surface of the hollow shaft (2), and the other end of the rotor component (4) is rotatably connected to the outer shell (1). The stator component (5) and the hollow shaft (2) are rotatably connected by bushings. The two ends of the hollow shaft (2) are rotatably connected to the front cover (3) and the rear cover (31) respectively by bushings.

3. The external rotor motor of the integrated thermal management system according to claim 1, characterized in that: The hollow shaft (2) is equipped with an exhaust pipe (201) and a boss (202). The diameter of the side surface of the boss (202) near the front cover (3) is smaller than the diameter of the side surface of the boss (202) away from the front cover (3). The exhaust pipe (201) is located in the middle between the end of the stator (5) near the front cover (3) and the end of the rotor (4) near the front cover (3).

4. The external rotor motor of the integrated thermal management system according to claim 1, characterized in that: The movable sealing ring (102), the fitting groove (106) and the closing groove (104) have the same cross-sectional area, and the depth of the closing groove (104) is greater than the thickness of the movable sealing ring (102). The cross-section of the central ring (101) is the same as that of the hollow rotating shaft (2). A displacement sensor is installed inside the movable sealing ring (102).

5. The external rotor motor of the integrated thermal management system according to claim 1, characterized in that: The horizontal distance between the side surface of the fitting groove (106) near the centering ring (101) and the side surface of the closing groove (104) near the centering ring (101) is less than the thickness of the movable sealing ring (102).

6. The external rotor motor of the integrated thermal management system according to claim 3, characterized in that: The end of the air guide ring (9) is fixedly sealed to the surface of the rotor (4), and the end of the air guide ring (9) is rotated sealed to the surface of the stator (5). The air inlet pipe (7) and the exhaust pipe (201) are both equipped with one-way valves, and the surface of the air supply pipe (8) is connected to a branch pipe (81) that is connected to the through pipe (107) and a tail pipe (82) that supplies air to the hollow rotating shaft (2).

7. The external rotor motor of the integrated thermal management system according to claim 1, characterized in that: Each of the central rings (101) has a sealing ring (11) made of shape memory alloy material fixedly connected to its outer surface through an outer ring, and the cross-sectional width of the sealing ring (11) in the initial state is greater than the horizontal distance between two adjacent stators (5).

8. The external rotor motor of the integrated thermal management system according to claim 7, characterized in that: Each of the sealing rings (11) is in sliding contact with the outer surfaces of the two adjacent stator members (5), and an elastic pad is installed on the inner surface of the sealing ring (11).

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