A motor using a phase change heat pipe

Abstract

This invention belongs to the field of motor design technology, specifically relating to a motor employing phase change heat pipes, equipped with a rotor, shaft, heat pipes, and heat sinks. The motor includes a motor housing, stator, stator windings, and rotor, and drives a hollow shaft to rotate. The heat pipes include: an outer circumferential heat pipe on the rotor support, an inner circumferential heat pipe on the rotor support, and a middle circumferential heat pipe on the rotor support. The motor cools the rotor through gas-liquid two-phase phase change technology. The heat pipes are arranged in three rings, on the outer circumference, inner circumference, and outer circumference of the inner hole of the rotor support, rotating with the rotor. The evaporation section of the heat pipes directly exchanges heat with the motor rotor. The liquid evaporates and absorbs heat, carrying away the heat from the rotor and the rotor permanent magnets. The gas then enters the condensation section through the transmission section, rapidly dissipating heat and cooling, condensing into liquid. Due to the centrifugal force of the rotating shaft, the liquid returns to the evaporation section, circulating and cooling.

Description

Technical Field

[0001] This invention belongs to the field of motor design technology, and specifically relates to a motor that uses a phase change heat pipe. Background Technology

[0002] With the rapid development of the vehicle and aviation sectors, propulsion systems for flying cars, land-to-air mobile platforms, and aircraft have placed demands on lightweight and integrated propulsion motors. The high power and frequency of these motors lead to a rapid increase in eddy current losses in the permanent magnets, resulting in significant heat generation. When the permanent magnet temperature becomes too high, demagnetization can occur, causing a sharp decline in motor performance. Axial flux motors have a compact internal structure, making rotor cooling and heat dissipation extremely challenging.

[0003] Chinese invention patent CN118232577A provides a disc motor and cooling method with rotor oil spray cooling. Oil is sprayed radially from the center of the rotating shaft to the outer circumference of the rotor support, which has a good cooling effect. However, it requires an additional oil pump system. For the whole vehicle / machine, adding oil tank, oil and pipeline will increase the weight significantly. In addition, adding oil circuits to rotating parts will cause dynamic sealing problems.

[0004] Chinese invention patents CN108539888A and CN113949188A, among others, have proposed cooling methods and structures such as rotor air cooling. However, these patents all involve adding a fan to the rotor shaft. Since the fan blades drive external air into the air passage, dust from the outside air will be brought into the motor, which reduces the motor's safety. Furthermore, pure air-cooled rotors have low heat dissipation efficiency for permanent magnets.

[0005] Chinese invention patents CN106981950A, CN110718979A, CN118848653A, CN114828574A, CN117650652A, etc., all use rotor heat pipes to fully cool the rotor. However, by adding heat sinks, fans, etc. in the axial direction of the motor to cool the condensation section of the heat pipe, the axial length of the motor is greatly increased, and the increased axial length also brings additional weight.

[0006] Chinese invention patents CN107617751A, CN118842217A, CN113922537A, and CN107717625A also use rotor heat pipes to fully cool the rotor. However, the method of setting coolant to cool the condensation section of the heat pipe will cause the coolant to continuously accumulate heat and rise in temperature, which may lead to the risk that the heat pipe will not work after long-term operation. On the other hand, if the coolant is discharged for heat exchange, there will be the need to increase the heat exchange components and the dynamic sealing problem of adding coolant to the rotating rotor.

[0007] Chinese invention patent CN104578504A cools the motor rotor by filling the motor shaft cavity with a phase change heat transfer medium and combining the rotor and shaft to form a heat pipe structure. On the one hand, the motor shaft itself has a high temperature, so its cooling effect as a condensation section is poor. On the other hand, the entire shaft as a heat pipe has high requirements for the shaft processing technology, which increases the complexity. Summary of the Invention

[0008] (a) Technical problems to be solved

[0009] The technical problem to be solved by this invention is: how to provide a rotor structure and motor that can improve the cooling efficiency of the motor rotor, reduce the weight of the motor, improve the heat exchange efficiency of the heat pipe, and minimize the increase in the volume of the motor body, while the motor structure should have a small impact on the aerodynamic performance of the duct / propeller.

[0010] (II) Technical Solution

[0011] To solve the above technical problems, the present invention provides a motor using a phase change heat pipe, wherein the motor (3) is equipped with a rotor (1), a shaft (2), a heat pipe (4), and a heat sink (5);

[0012] The rotor (1) and the motor (3) are connected on the shaft (2);

[0013] The shaft (2) includes an air inlet baffle (21), an air inlet (22), and a hollow shaft (23); the air inlet (22) and the air inlet baffle (21) are both located on the outer wall of the hollow shaft (23); the air inlet (22) penetrates the wall of the hollow shaft (23) to the inner cavity of the hollow shaft (23); the air inlet baffle (21) is set on the outer wall of the hollow shaft (23) between the air inlet (22) and the motor (3) to form a sliding flow guiding space;

[0014] The motor (3) includes a motor housing (31), a stator (32), a stator winding (33), and a rotor (34). The motor (3) drives the hollow shaft (23) to rotate.

[0015] The hollow shaft (23) has heat sinks (5) arranged on the inner wall of its cavity;

[0016] The rotor (34) includes: a rotor support (341) and a permanent magnet (342); the rotor support (341) is a hollow ring structure, and the rotor support (341) has three concentric circumferential ring structures arranged radially outward from the center: the inner circumference (3411) of the rotor support, the middle circumference (3412) of the rotor support, and the outer circumference (3413) of the rotor support;

[0017] The heat pipe (4) includes: an outer circumferential heat pipe (411) of the rotor support, an inner circumferential heat pipe (412) of the rotor support, and a middle circumferential heat pipe (413) of the rotor support, all of which are annular. The outer circumferential heat pipe (411) and the middle circumferential heat pipe (413) of the rotor support are connected by two symmetrically arranged first straight pipes, and the middle circumferential heat pipe (413) and the inner circumferential heat pipe (412) of the rotor support are also connected by two symmetrically arranged second straight pipes. The outer circumferential heat pipe (411) of the rotor support is located inside the outer circumference (3413) of the rotor support, the middle circumferential heat pipe (413) of the rotor support is located inside the middle circumference (3412) of the rotor support, and the inner circumferential heat pipe (412) of the rotor support is located outside the inner circumference (3411) of the rotor support.

[0018] The outer circumferential heat pipe (411) of the rotor support, the middle circumferential heat pipe (413) of the rotor support, and the first straight pipe of the connection between the two constitute the evaporation section (41), and the inner circumferential heat pipe (412) of the rotor support constitutes the condensation section (42), thereby ensuring the dynamic balance of the rotor support while realizing the gas-liquid two-phase phase change cycle.

[0019] The motor (3) uses a gas-liquid two-phase phase change technology to cool the motor rotor (34). When the rotor (1) rotates, a backward slip flow is generated. The air inlet baffle (21) guides the slip flow through the air inlet (22) into the heat sink (5) inside the hollow shaft (23). The high-speed, low-temperature slip flow passes through the heat sink (5) and carries away the heat in the heat pipe (4), so that the water vapor in the heat pipe (4) can be quickly cooled and condensed into liquid when it enters the condensation section (42). Due to the centrifugal effect of the rotor support rotation, the liquid returns to the evaporation section (41) through the first straight pipe and the second straight pipe, evaporates into water vapor, and is cooled in a cycle.

[0020] The air inlet baffle (21) extends in an arc shape in front of the air inlet (22), thereby forming a slip flow guiding space.

[0021] The air inlet (22) and the air inlet baffle (21) are circumferentially distributed on the outer wall of the hollow shaft (23), with four of each evenly arranged, forming a structure that guides the sliding flow into the hollow shaft (23).

[0022] The air inlet (22) is a square hole.

[0023] The length of the heat sink (5) along the axial direction of the hollow shaft (23) is consistent with the thickness of the motor (3), and it is a long thin plate. 90 of them are arranged in a circumferential array along the inner wall of the hollow shaft (23).

[0024] The inner circumference (3411) of the rotor support is coaxially fixed with the outer circumference of the shaft (2).

[0025] The permanent magnet (342) is embedded between the middle circumference (3412) of the rotor support and the outer circumference (3413) of the rotor support.

[0026] The heat pipe (4) rotates together with the rotor (34), and the outer diameter of the heat pipe (4) is 10 mm and the inner diameter is 8 mm.

[0027] The motor (3) uses the heat sink (5) in the hollow shaft (23) and the heat pipe (4) in the rotor bracket to carry out a gas-liquid two-phase phase change cycle, which cleverly utilizes the motor structure to make the motor body a sealed whole with a sealing level of IP67 or higher.

[0028] (III) Beneficial Effects

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] (1) This invention provides a motor using a phase change heat pipe, which cools the motor rotor through a gas-liquid two-phase phase change technology. The heat pipe is arranged in three rings, on the outer circumference, inner circumference and outer circumference of the rotor support, and rotates with the rotor. The evaporation section of the heat pipe directly exchanges heat with the motor rotor. The liquid evaporates and absorbs heat, taking away the heat from the rotor and the rotor permanent magnet. The gas enters the condensation section through the transmission section, quickly dissipates heat and cools, and condenses into liquid. Due to the centrifugal effect of the rotating shaft, the liquid returns to the evaporation section and circulates to cool down.

[0031] (2) The present invention provides a motor using a phase change heat pipe, wherein the rotor shaft is designed as a hollow shaft and heat dissipation fins are provided on the inner side of the hollow shaft. This structure design cleverly utilizes the motor structure, making the motor body a sealed whole with a sealing level of IP67 or higher, thus solving the problem of low air cooling efficiency of high sealing level motors.

[0032] (3) The present invention provides a motor using a phase change heat pipe, with an air inlet baffle structure on the hollow shaft between the motor and the rotor to introduce the slip flow of the propeller. At the same time, through structural design, it can introduce high-speed, low-temperature gas while minimizing the impact on the aerodynamic characteristics of the duct / propeller.

[0033] (4) The present invention provides a motor using a phase change heat pipe. By installing the heat pipe inside the motor rotor, combined with the design of the air inlet baffle and hollow rotor shaft, the problems of increased weight and sealing caused by existing cooling methods such as separately adding condensate, motor not being sealed, and adding circulating oil cooling can be eliminated. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the overall structure of the technical solution of the present invention;

[0035] Figure 2 This is a schematic diagram of the internal structure of the motor of the present invention;

[0036] Figure 3 This is a cross-sectional view of the motor of the present invention;

[0037] Figure 4 for Figure 3 A schematic diagram of the heat pipe arrangement of the motor of the present invention, shown along the AA direction. Detailed Implementation

[0038] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0039] To improve rotor cooling efficiency, reduce motor weight, enhance heat pipe heat exchange efficiency, and minimize the increase in motor body volume while ensuring minimal impact on duct / propeller aerodynamic performance, this invention proposes a motor employing a phase-change heat pipe. The motor utilizes an axial flux motor structure with a phase-change heat pipe rotor. Heat sinks are arranged within a hollow rotor shaft, and a petal-shaped structure at the shaft end introduces some propeller slipflow. This high-velocity, low-temperature slipflow effectively dissipates heat from the heat pipe's condensation section. This results in a high-power-density motor, improving the thrust-to-weight ratio of propulsion systems in flying cars, air-to-ground mobile platforms, and aircraft.

[0040] To solve the above-mentioned technical problems, the present invention provides a motor employing a phase change heat pipe, such as... Figures 1-3 As shown, the motor (3) is equipped with a rotor (1), a shaft (2), a heat pipe (4), and a heat sink (5);

[0041] The rotor (1) and the motor (3) are connected on the shaft (2);

[0042] The shaft (2) includes an air inlet baffle (21), an air inlet (22), and a hollow shaft (23); the air inlet (22) and the air inlet baffle (21) are both located on the outer wall of the hollow shaft (23); the air inlet (22) penetrates the wall of the hollow shaft (23) to the inner cavity of the hollow shaft (23); the air inlet baffle (21) is set on the outer wall of the hollow shaft (23) between the air inlet (22) and the motor (3) to form a sliding flow guiding space;

[0043] The motor (3) includes a motor housing (31), a stator (32), a stator winding (33), and a rotor (34). The motor (3) drives the hollow shaft (23) to rotate.

[0044] The hollow shaft (23) has heat sinks (5) arranged on the inner wall of its cavity;

[0045] like Figure 4As shown, the rotor (34) includes: a rotor support (341) and a permanent magnet (342); the rotor support (341) is a hollow ring structure, and the rotor support (341) has three concentric circumferential ring structures arranged radially outward from the center: the inner circumference (3411) of the rotor support, the middle circumference (3412) of the rotor support, and the outer circumference (3413) of the rotor support;

[0046] The heat pipe (4) includes: an outer circumferential heat pipe (411) of the rotor support, an inner circumferential heat pipe (412) of the rotor support, and a middle circumferential heat pipe (413) of the rotor support, all of which are annular. The outer circumferential heat pipe (411) and the middle circumferential heat pipe (413) of the rotor support are connected by two symmetrically arranged first straight pipes, and the middle circumferential heat pipe (413) and the inner circumferential heat pipe (412) of the rotor support are also connected by two symmetrically arranged second straight pipes. The outer circumferential heat pipe (411) of the rotor support is located inside the outer circumference (3413) of the rotor support, the middle circumferential heat pipe (413) of the rotor support is located inside the middle circumference (3412) of the rotor support, and the inner circumferential heat pipe (412) of the rotor support is located outside the inner circumference (3411) of the rotor support.

[0047] The outer circumferential heat pipe (411) of the rotor support, the middle circumferential heat pipe (413) of the rotor support, and the first straight pipe of the connection between the two constitute the evaporation section (41), and the inner circumferential heat pipe (412) of the rotor support constitutes the condensation section (42), thereby ensuring the dynamic balance of the rotor support while realizing the gas-liquid two-phase phase change cycle.

[0048] The motor (3) employs a gas-liquid two-phase phase change technology to cool the motor rotor (34); for example... Figure 1 As shown, when the rotor (1) rotates, a backward slip flow is generated. The air inlet baffle (21) guides the slip flow through the air inlet (22) into the heat sink (5) inside the hollow shaft (23). The high-speed, low-temperature slip flow passes through the heat sink (5) and carries away the heat in the heat pipe (4), so that the water vapor in the heat pipe (4) can be quickly cooled and condensed into liquid when it enters the condensation section (42). Due to the centrifugal effect of the rotor support rotation, the liquid returns to the evaporation section (41) through the first straight pipe and the second straight pipe, evaporates into water vapor, and is cooled in a cycle.

[0049] The air inlet baffle (21) extends in an arc shape towards the front of the air inlet (22), thereby forming a slipflow guiding space. The air inlet baffle (21) minimizes the impact on the airflow and more efficiently introduces the slipflow generated by the rotation of the rotor (1) into the hollow shaft (23).

[0050] The air inlet (22) and the air inlet baffle (21) are circumferentially distributed on the outer wall of the hollow shaft (23), with four of each evenly arranged, forming a structure that guides the sliding flow into the hollow shaft (23).

[0051] The air inlet (22) is a square hole.

[0052] The length of the heat sink (5) along the axial direction of the hollow shaft (23) is consistent with the thickness of the motor (3), and it is a long thin plate. 90 of them are arranged in a circumferential array along the inner wall of the hollow shaft (23).

[0053] The inner circumference (3411) of the rotor support is coaxially fixed with the outer circumference of the shaft (2).

[0054] The permanent magnet (342) is embedded between the middle circumference (3412) of the rotor support and the outer circumference (3413) of the rotor support.

[0055] The heat pipe (4) rotates together with the rotor (34), and the outer diameter of the heat pipe (4) is 10 mm and the inner diameter is 8 mm.

[0056] The motor (3) uses the heat sink (5) in the hollow shaft (23) and the heat pipe (4) in the rotor bracket to carry out a gas-liquid two-phase phase change cycle, which cleverly utilizes the motor structure to make the motor body a sealed whole with a sealing level of IP67 or higher.

[0057] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An electric machine employing a phase change heat pipe, characterized by, The motor (3) is equipped with a rotor (1), a shaft (2), a heat pipe (4), and a heat sink (5); The rotor (1) and the motor (3) are connected on the shaft (2); The shaft (2) includes an air inlet baffle (21), an air inlet (22), and a hollow shaft (23); the air inlet (22) and the air inlet baffle (21) are both located on the outer wall of the hollow shaft (23); the air inlet (22) penetrates the wall of the hollow shaft (23) to the inner cavity of the hollow shaft (23); the air inlet baffle (21) is set on the outer wall of the hollow shaft (23) between the air inlet (22) and the motor (3) to form a sliding flow guiding space; The motor (3) includes a motor housing (31), a stator (32), a stator winding (33), and a rotor (34). The motor (3) drives the hollow shaft (23) to rotate. The hollow shaft (23) has heat sinks (5) arranged on the inner wall of its cavity; The rotor (34) includes: a rotor support (341) and a permanent magnet (342); the rotor support (341) is a hollow ring structure, and the rotor support (341) has three concentric circumferential ring structures arranged radially outward from the center: the inner circumference (3411) of the rotor support, the middle circumference (3412) of the rotor support, and the outer circumference (3413) of the rotor support; The heat pipe (4) includes: an outer circumferential heat pipe (411) of the rotor support, an inner circumferential heat pipe (412) of the rotor support, and a middle circumferential heat pipe (413) of the rotor support, all of which are annular. The outer circumferential heat pipe (411) and the middle circumferential heat pipe (413) of the rotor support are connected by two symmetrically arranged first straight pipes, and the middle circumferential heat pipe (413) and the inner circumferential heat pipe (412) of the rotor support are also connected by two symmetrically arranged second straight pipes. The outer circumferential heat pipe (411) of the rotor support is located inside the outer circumference (3413) of the rotor support, the middle circumferential heat pipe (413) of the rotor support is located inside the middle circumference (3412) of the rotor support, and the inner circumferential heat pipe (412) of the rotor support is located outside the inner circumference (3411) of the rotor support. The outer circumferential heat pipe (411) of the rotor support, the middle circumferential heat pipe (413) of the rotor support, and the first straight pipe of the connection between the two constitute the evaporation section (41), and the inner circumferential heat pipe (412) of the rotor support constitutes the condensation section (42), thereby ensuring the dynamic balance of the rotor support while realizing the gas-liquid two-phase phase change cycle.

2. The electric machine employing a phase change heat pipe according to claim 1, wherein The motor (3) uses a gas-liquid two-phase phase change technology to cool the motor rotor (34). When the rotor (1) rotates, a backward slip flow is generated. The air inlet baffle (21) guides the slip flow through the air inlet (22) into the heat sink (5) inside the hollow shaft (23). The high-speed, low-temperature slip flow passes through the heat sink (5) and carries away the heat in the heat pipe (4), so that the water vapor in the heat pipe (4) can be quickly cooled and condensed into liquid when it enters the condensation section (42). Due to the centrifugal effect of the rotor support rotation, the liquid returns to the evaporation section (41) through the first straight pipe and the second straight pipe, evaporates into water vapor, and is cooled in a cycle.

3. The motor employing a phase change heat pipe as described in claim 1, characterized in that, The air inlet baffle (21) extends in an arc shape in front of the air inlet (22), thereby forming a slip flow guiding space.

4. The motor employing a phase change heat pipe as described in claim 1, characterized in that, The air inlet (22) and the air inlet baffle (21) are circumferentially distributed on the outer wall of the hollow shaft (23), with four of each evenly arranged, together forming a structure that guides the sliding flow into the hollow shaft (23).

5. The motor employing a phase change heat pipe as described in claim 1, characterized in that, The air inlet (22) is a square hole.

6. The motor employing a phase change heat pipe as described in claim 1, characterized in that, The length of the heat sink (5) in the axial direction of the hollow shaft (23) is consistent with the thickness of the motor (3), and it is a long thin plate. 90 of them are arranged in a circumferential array along the inner wall of the hollow shaft (23).

7. The motor employing a phase change heat pipe as described in claim 1, characterized in that, The inner circumference (3411) of the rotor support is coaxially fixed with the outer circumference of the shaft (2).

8. The motor employing a phase change heat pipe as described in claim 1, characterized in that, The permanent magnet (342) is embedded between the middle circumference (3412) of the rotor support and the outer circumference (3413) of the rotor support.

9. The motor employing a phase change heat pipe as described in claim 1, characterized in that, The heat pipe (4) rotates together with the rotor (34). The outer diameter of the heat pipe (4) is 10 mm and the inner diameter is 8 mm.

10. The motor employing a phase change heat pipe as described in claim 1, characterized in that, The motor (3) uses the heat sink (5) in the hollow shaft (23) and the heat pipe (4) in the rotor support to carry out a gas-liquid two-phase phase change cycle, which cleverly utilizes the motor structure to make the motor body a sealed whole with a sealing level of IP67 or higher.

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