A heat dissipation structure of an in-wheel motor

Abstract

The utility model discloses a kind of heat dissipation structure of in-wheel motor, it is related to motor cooling technical field;Including water inlet pipe and return pipe, integrated cooling pipeline is arranged between the water inlet pipe and the return pipe, the integrated cooling pipeline is connected with stator assembly and is arranged inside the stator assembly, heat absorption ring is also arranged in the stator assembly, the water inlet pipe and the return pipe are fixed in the side of the stator assembly, the input end of the integrated cooling pipeline is connected with the water inlet pipe, the output end of the cooling pipeline is connected with the return pipe;The utility model uses above-mentioned one kind of heat dissipation structure of in-wheel motor, realizes the comprehensive optimization of heat dissipation performance, reliability, compactness and cost control, provides key technical support for developing higher performance in-wheel motor.

Description

Technical Field

[0001] This utility model relates to the field of motor cooling technology, and in particular to a heat dissipation structure for a hub motor. Background Technology

[0002] Traditional water-cooling methods for motors are severely inadequate for high-power hub motors. Built-in cooling pipes have limitations, such as: they cannot evenly cover the entire heat-generating area, leading to localized overheating; there is contact thermal resistance between the cooling pipes and the stator core or stator frame, affecting heat transfer efficiency; and the complex pipe structure requires additional processing and assembly, increasing the risk of leakage and manufacturing costs.

[0003] In-wheel motors integrate components such as motors, brakes, and suspensions within the wheel, resulting in a very compact space. This makes it impossible to install large external radiators or fans like traditional motors, and heat dissipation becomes the main bottleneck limiting its power output and continuous operation. Utility Model Content

[0004] The purpose of this invention is to provide a heat dissipation structure for a hub motor, which constructs a complete and efficient heat dissipation chain with "low thermal resistance, high coverage, and integration" from the heat source (winding) to the final heat dissipation medium (coolant). It not only solves the fundamental problem of "difficult heat dissipation" in traditional hub motors, but also achieves comprehensive optimization of heat dissipation performance, reliability, compactness, and cost control through ingenious structural design, providing key technical support for the development of higher performance hub motors.

[0005] To achieve the above objectives, this utility model provides a heat dissipation structure for a hub motor, including an inlet pipe and a return pipe. An integrated cooling pipe is provided between the inlet pipe and the return pipe. The integrated cooling pipe is connected to a stator assembly and is disposed inside the stator assembly. A heat-absorbing ring is also provided inside the stator assembly. The inlet pipe and the return pipe are fixed to one side of the stator assembly. The input end of the integrated cooling pipe is connected to the inlet pipe, and the output end of the cooling pipe is connected to the return pipe.

[0006] Preferably, one end of the water inlet pipe and the water return pipe are connected to the stator assembly, and the other end is connected to an electronic pump. The heat absorption ring is configured as a pre-formed ring and is made of insulating and thermally conductive material.

[0007] Preferably, a rotor assembly is disposed outside the stator assembly, a motor shaft is disposed inside the stator assembly, a plurality of bearings are disposed on the motor shaft, the motor shaft is connected to the stator assembly through the bearings, and a protective shell is disposed around the rotor assembly.

[0008] Preferably, the stator assembly includes a stator frame, a stator core, and windings arranged sequentially from the inside out, and the rotor assembly includes permanent magnet poles, a rotor yoke, and a rotor base arranged sequentially from the inside out.

[0009] Preferably, the heat-absorbing ring is provided between the stator core and the winding.

[0010] Preferably, the integrated cooling pipes are installed inside the stator frame, and the length of the integrated cooling pipes is not less than 50 cm per 50 square centimeters. centimeter.

[0011] Preferably, the integrated cooling pipe is spiral or coiled around the inside of the stator frame, and the stator frame housing is provided with inlet pipe holes and return pipe holes.

[0012] Preferably, the cross-section of the integrated cooling pipe is set to semi-circular.

[0013] Therefore, the heat dissipation structure of the hub motor of this utility model, which adopts the above-described structure, has the following advantages compared with the prior art: The technical solution of this invention significantly improves the heat dissipation capacity of the in-wheel motor, allowing the motor to withstand higher current and power output within the same volume, or to be designed to be smaller and lighter while maintaining the same power. This is particularly important for electric vehicles that pursue lightweight design and high performance, directly increasing the power density of the in-wheel motor. The integrated design of the "integrated cooling pipes" and the stator frame (whether cast or 3D printed) eliminates the need for traditional external piping and complex assembly processes, making the entire heat dissipation system more compact and reliable, reducing potential leakage points, and perfectly meeting the stringent requirements of hub motors for space and integration.

[0014] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0015] Figure 1 This is an overall structural diagram of an embodiment of the heat dissipation structure for a hub motor according to the present invention; Figure 2 This is a diagram showing the integrated cooling pipe distribution of an embodiment of the heat dissipation structure for a hub motor according to the present invention. Figure 3 This is a structural diagram of an integrated cooling pipe for an embodiment of the heat dissipation structure of a hub motor according to the present invention.

[0016] Figure Labels 1. Inlet pipe; 2. Return pipe; 3. Integrated cooling pipe; 4. Stator assembly; 41. Stator frame; 42. Stator core; 43. Winding; 5. Heat absorption ring; 6. Electric pump; 7. Rotor assembly; 71. Permanent magnet pole; 72. Rotor yoke; 73. Rotor base; 8. Motor shaft; 9. Bearing; 10. Protective housing; 11. Inlet pipe through hole; 12. Return pipe through hole. Detailed Implementation

[0017] In the description of this utility model, it should be noted that the terms "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0018] Example like Figures 1-3 As shown, the present invention discloses a heat dissipation structure for a hub motor, including an inlet pipe 1 and a return pipe 2. An integrated cooling pipe 3 is provided between the inlet pipe 1 and the return pipe 2. The integrated cooling pipe 3 is connected to a stator assembly 4 and is located inside the stator assembly 4. A heat-absorbing ring 5 is also provided inside the stator assembly 4. The inlet pipe 1 and the return pipe 2 are fixed on one side of the stator assembly 4. The input end of the integrated cooling pipe 3 is connected to the inlet pipe 1, and the output end of the cooling pipe is connected to the return pipe 2. By setting an insulating and heat-conducting heat-absorbing ring 5 between the stator core 42 and the winding 43, the problem of poor thermal conductivity of traditional insulating materials is directly solved. The heat-absorbing ring 5 can quickly "pull" the heat generated by the winding 43 to the stator core 42. After the heat reaches the stator core 42, it is quickly absorbed by the integrated cooling pipe 3 in the stator frame 41 adjacent to the stator core 42. Since the pipe is "integrated", it is in close contact with the frame and has minimal thermal resistance.

[0019] One end of the inlet pipe 1 and the return pipe 2 are connected to the stator assembly 4, and the other end is connected to the electric pump 6. The heat absorption ring 5 is set as a pre-formed ring and is made of insulating and heat-conducting material.

[0020] The stator assembly 4 is externally provided with a rotor assembly 7, and the stator assembly 4 is internally provided with a motor shaft 8. Several bearings 9 are provided on the motor shaft 8, and the motor shaft 8 is connected to the stator assembly 4 through the bearings 9. The rotor assembly 7 is externally provided with a protective shell 10.

[0021] The stator assembly 4 includes a stator frame 41, a stator core 42 and a winding 43 arranged sequentially from the inside to the outside, and the rotor assembly 7 includes a permanent magnet pole 71, a rotor yoke 72 and a rotor base 73 arranged sequentially from the inside to the outside.

[0022] A heat-absorbing ring 5 is installed between the stator core 42 and the winding 43, serving the dual functions of electrical insulation and heat conduction. Reliable electrical insulation must be maintained between the motor winding 43 and the core; otherwise, a short circuit will occur, leading to immediate motor failure. This optimizes the internal temperature distribution of the motor, improves overall heat dissipation efficiency, and prevents localized overheating. The heat-absorbing ring 5 is a "pre-formed ring" that fits tightly and evenly between the winding 43 and the core. This structure ensures that the heat generated by each turn of the winding 43 is evenly absorbed, preventing heat accumulation at certain points and the formation of localized hot spots, thus reducing the temperature rise of the winding 43. By rapidly dissipating heat from the winding 43, the heat-absorbing ring 5 directly lowers the operating temperature of the winding 43. This is beneficial for protecting the insulation of the winding 43 and preventing aging. Improving the motor's overload capacity and continuous operating power is crucial. Enhancing the efficiency of subsequent heat dissipation processes is essential. Heat is efficiently transferred from the heat-absorbing ring 5 to the stator core 42, and then from the core to the cooling pipes integrated in the frame. Due to the significantly improved conduction efficiency at the front end (winding core 43), the "bottleneck" of the entire heat dissipation chain is broken, allowing the efficiency of the downstream water cooling system to be fully utilized. The heat-absorbing ring 5 perfectly solves this problem. It uses insulating and thermally conductive materials (such as boron nitride ceramic, special thermally conductive composite plastic, thermally conductive silicone, etc.). It can ensure electrical safety isolation between the winding 43 and the core, and can also conduct heat as efficiently as metal. It combines two originally contradictory requirements into one, which is a major highlight of this technical solution.

[0023] The stator frame 41 is equipped with integrated cooling pipes 3. The length of the integrated cooling pipes 3 is not less than 50 centimeters in every 50 square centimeters area. The integrated cooling pipes 3 are spiral or coiled around the inside of the stator frame 41. The shell of the stator frame 41 is provided with inlet pipe holes 11 and return pipe holes 12. The phrases "the length is not less than 50 centimeters in every 50 square centimeters area" and "the length is spiral or coiled" ensure that the cooling pipes can uniformly and densely cover the entire stator frame 41, without any heat dissipation dead corners, and achieve "carpet-like" cooling of the heat source.

[0024] The integrated cooling pipe 3 has a semi-circular cross-section. Designing the pipe cross-section as a semi-circular shape allows its flat side to fit against the inner wall of the stator frame 41 with the maximum area, while the curved side can achieve smooth liquid flow with a small space occupation. It is an optimized balance between space utilization and heat conduction efficiency.

[0025] In the specific implementation process Phase 1: System Startup and Cooling Cycle Establishment System power-on: When the electric vehicle starts or the hub motor controller issues a running command, the electronic pump connected to the inlet and outlet water pipes starts synchronously.

[0026] Coolant circulation: The electric pump starts working, generating pressure and driving the coolant (usually a mixture of water and ethylene glycol) to be drawn from the external radiator or reservoir.

[0027] Entering the stator assembly: The coolant first flows through the inlet pipe, through the inlet pipe hole on the stator assembly housing, and then enters the input end of the integrated cooling pipe inside the stator frame.

[0028] Establish a loop path: At this point, a loop starts from the "inlet pipe" Integrated cooling pipes return water pipe electric pump A complete coolant circulation loop for the "external radiator" has been established.

[0029] Phase Two: Heat Generation and Efficient Conduction Heat generation during motor operation: As the motor is powered on, the current passes through the stator windings, generating a large amount of Joule heat (copper loss); at the same time, the changing magnetic field generates eddy currents and hysteresis losses (iron loss) in the stator core. These two parts are the main heat sources of the motor.

[0030] First-stage heat conduction (winding) Heat absorption ring: The heat generated by the winding is first transferred to the heat absorption ring that tightly wraps around it through heat conduction. Since the heat absorption ring is an insulating and thermally conductive material, it not only ensures the electrical insulation between the winding and the iron core, but also acts like a "thermal conductive sponge" to quickly absorb the heat from the winding.

[0031] Secondary heat conduction (heat absorption ring) Stator core: The heat absorbed by the heat-absorbing ring continues to be conducted outwards to the stator core, which is in close contact with it. At this point, the heat from the winding has efficiently crossed the insulation barrier and accumulated on the stator core.

[0032] Third-stage heat conduction (stator core) Stator frame: Heat is further conducted from the stator core to the integrated stator frame. The stator frame becomes the "heat distribution center".

[0033] Phase 3: Heat Exchange and Liquid Cooling Fourth stage heat conduction (stator frame) Cooling pipes: The heat collected on the stator frame is transferred through heat conduction through the frame wall to the wall of the integrated cooling pipes embedded inside it.

[0034] Advantages of efficient contact design: Because the cross-section of the cooling pipe is semi-circular, its flat side is in close contact with the inner wall of the frame over a large area, which greatly reduces the contact thermal resistance, allowing heat to be transferred from the frame to the pipe wall very quickly.

[0035] Convection heat transfer (pipe wall) Coolant: When coolant flows at high speed through spiral or coiled pipes, the heat from the pipe walls is rapidly carried away by the flowing coolant through convection heat transfer. The coolant's own temperature rises.

[0036] Uniform cooling effect: spiral pipe layout and high-density laying (every 50cm) 2 No less than 50 (cm) ensures that the coolant can flow through every area of ​​the stator frame, providing uniform and thorough "carpet-like" cooling to the entire motor, effectively preventing localized overheating.

[0037] Phase 4: Heat Dissipation and Intelligent Temperature Control Heat dissipation: The high-temperature coolant, carrying a large amount of heat, flows along the path of the integrated cooling pipe and eventually exits from its output end into the return water pipe.

[0038] Circulation to external heat dissipation: The high-temperature coolant is sent back to the main radiator (or a separate coolant radiator) at the front of the vehicle through the return pipe. In the radiator, the heat is released into the atmosphere by forced air cooling through the fan, and the coolant temperature drops.

[0039] Complete the cycle: The cooled coolant is pumped back into the inlet pipe by the electric pump to start a new cooling cycle.

[0040] Intelligent temperature control (optional but common): Throughout the process, if the system is equipped with a temperature sensor (usually located in the stator assembly), the speed of the electric pump can be intelligently adjusted based on temperature feedback.

[0041] At low temperatures and low loads: the motor generates less heat, and the electric pump can run at low speed, saving energy.

[0042] Under high temperature / high load conditions: such as when the vehicle accelerates rapidly or climbs a hill, the heat generated by the motor increases dramatically. When the temperature sensor detects the temperature rise, the electric pump will increase its speed, accelerate the circulation flow of coolant, enhance heat dissipation, and ensure that the motor temperature is always kept within a safe operating range.

[0043] Therefore, the present invention provides a heat dissipation structure for a hub motor with the above-mentioned structure, which constructs a complete and efficient heat dissipation chain with "low thermal resistance, high coverage, and integration" from the heat source (winding) to the final heat dissipation medium (coolant). It not only solves the fundamental problem of "difficult heat dissipation" in traditional hub motors, but also achieves comprehensive optimization of heat dissipation performance, reliability, compactness, and cost control through ingenious structural design, providing key technical support for the development of higher performance hub motors.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solution of this utility model, and these modifications or equivalent substitutions cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of this utility model.

Claims

1. A heat dissipation structure for a hub motor, characterized in that: It includes an inlet pipe and a return pipe, and an integrated cooling pipe is provided between the inlet pipe and the return pipe. The integrated cooling pipe is connected to the stator assembly and is located inside the stator assembly. A heat absorption ring is also provided inside the stator assembly. The inlet pipe and the return pipe are fixed to one side of the stator assembly. The input end of the integrated cooling pipe is connected to the inlet pipe, and the output end of the cooling pipe is connected to the return pipe.

2. The heat dissipation structure for a hub motor according to claim 1, characterized in that: One end of the inlet pipe and the return pipe are connected to the stator assembly, and the other end is connected to an electronic pump. The heat absorption ring is a pre-formed ring and is made of insulating and thermally conductive material.

3. The heat dissipation structure for a hub motor according to claim 2, characterized in that: The stator assembly is externally provided with a rotor assembly, the stator assembly is internally provided with a motor shaft, the motor shaft is provided with several bearings, the motor shaft is connected to the stator assembly through the bearings, and the rotor assembly is externally provided with a protective shell.

4. The heat dissipation structure for a hub motor according to claim 3, characterized in that: The stator assembly includes a stator frame, a stator core, and windings arranged sequentially from the inside out, and the rotor assembly includes permanent magnet poles, a rotor yoke, and a rotor base arranged sequentially from the inside out.

5. The heat dissipation structure for a hub motor according to claim 4, characterized in that: The heat-absorbing ring is provided between the stator core and the winding.

6. The heat dissipation structure for a hub motor according to claim 4, characterized in that: The stator frame is equipped with integrated cooling pipes, and the length of the integrated cooling pipes is not less than 50 cm per 50 square centimeters. centimeter.

7. The heat dissipation structure for a hub motor according to claim 6, characterized in that: The integrated cooling pipes are spiral or coiled around the inside of the stator frame, and the stator frame housing is provided with inlet pipe holes and return pipe holes.

8. The heat dissipation structure for a hub motor according to claim 7, characterized in that: The integrated cooling pipe has a semi-circular cross-section.

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