A motor stator structure and electric propulsion system

Abstract

This invention discloses an electric propulsion system, relating to the field of aircraft heat dissipation structure technology, comprising: a stator assembly, wherein the inner circumference of the stator core is provided with a plurality of stator teeth; a stator winding, disposed on the stator teeth; a housing, which is a tubular structure, with the stator assembly disposed on the inner circumference of the housing, the housing having slots, and the outer circumferential surface of the housing being provided with a plurality of heat dissipation fins; and a heat pipe structure, wherein the heat-absorbing end of the heat pipe structure is disposed on the stator winding, and the heat-dissipating end of the heat pipe structure is disposed on the slot and cooperates with the heat dissipation fins for heat dissipation. The electric propulsion system provided in this application improves the heat dissipation effect by setting a heat pipe structure at the slot of the housing, with the heat dissipation end of the heat pipe structure disposed within the slot of the housing, and the heat-absorbing end of the heat pipe structure disposed on the stator winding for absorbing heat, in conjunction with the rotation of the propeller blades.

Description

Technical Field

[0001] This invention relates to the field of electric motor heat dissipation technology, and more specifically, to an electric motor stator structure and an electric propulsion system, particularly suitable for aircraft. Background Technology

[0002] With the rapid development of the low-altitude economy, electric vertical take-off and landing (eVTOL) aircraft, as an emerging form of aircraft, have attracted widespread attention. Among them, ducted eVTOLs have become an important development direction in the field of urban air mobility due to their advantages such as compact structure, low aerodynamic noise, and high safety. As the core power unit of ducted eVTOLs, the electric propulsion system directly determines the aircraft's range, payload capacity, and operational reliability.

[0003] However, ducted eVTOLs place extremely high design requirements on electric propulsion systems: on the one hand, the system needs to achieve high power density output within a limited space to reduce weight and increase payload; on the other hand, the heat dissipation problem caused by high-power operation becomes a key bottleneck restricting the improvement of system performance. Traditional electric propulsion systems typically design and install the duct, blades, motor, and motor controller separately, resulting in a loose overall system structure, large size, complex wiring, long heat dissipation paths, and high thermal resistance, making it difficult to meet the high power density and thermal management requirements of aerospace applications.

[0004] Currently, some technologies have attempted to improve the heat dissipation performance of motors and controllers by adding heat sink fins, air-cooled channels, or liquid-cooled structures. However, these solutions often increase the size and weight of the system, and the heat dissipation effect is still not ideal. Especially within the limited airflow space of the duct, how to efficiently and quickly transfer the heat generated by the main heat sources such as the motor stator windings to the external environment while maintaining the system's compactness is a technical challenge that urgently needs to be solved in the design of current electric propulsion systems.

[0005] In conclusion, improving the heat dissipation of motors is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide an electric propulsion system that can significantly improve the heat dissipation effect of the entire system through the arrangement of a heat pipe structure.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A motor stator structure, comprising:

[0009] The stator assembly has a number of stator teeth on the inner circumference of its stator core;

[0010] Stator windings are provided on the stator teeth;

[0011] The housing is a tubular structure, the stator assembly is located on the inner periphery of the housing, the housing is provided with slots, and the outer peripheral surface of the housing is provided with a number of heat dissipation fins.

[0012] The heat pipe structure has its heat absorption end located in the stator winding and its heat dissipation end located in the slot, and cooperates with the heat dissipation fins to dissipate heat.

[0013] Preferably, the heat pipe structure includes an annular tube, finned tubes, and right-angle tubes. The annular tube is a circular ring structure, the finned tubes are cuboid structures, and the right-angle tubes are L-shaped structures. Several finned tubes are provided and evenly distributed on the outer periphery of the annular tube, and several right-angle tubes are provided and evenly distributed on the inner periphery of the annular tube.

[0014] Preferably, the annular tube, the finned tube, and the right-angle tube are all hollow structures, and the cavities of the annular tube, the finned tube, and the right-angle tube are connected and combined to form a closed cavity, which contains a cooling medium.

[0015] Preferably, the first end of the right-angle tube is connected to the annular tube, a stator slot is provided between adjacent stator teeth (3), and the second end of the right-angle tube is located in the stator winding slot and between adjacent turns of the stator winding.

[0016] Preferably, the cooling medium is a phase change cooling medium.

[0017] Preferably, the cooling medium is water, and the inner walls of the annular tube, the finned tube, and the right-angle tube are provided with an anti-corrosion layer.

[0018] Preferably, the outer wall of the annular tube abuts against the inner wall of the housing, the number of finned tubes is the same as the number of slots and is arranged accordingly, the finned tubes are at least partially inserted into the slots and cooperate with the inner wall of the slots for heat transfer.

[0019] Preferably, the stator winding is fixed to the stator teeth by slot wedges, the stator teeth are connected to the stator yoke by pigeontail keys, and insulating adhesive is provided between the heat pipe structure and the stator assembly.

[0020] Preferably, insulating paper is provided between the straight section of the stator winding and the stator core, insulating end plates are provided between the two ends of the stator winding and the stator core, and the outer wall of the stator core is interference-fitted with the inner wall of the housing.

[0021] Preferably, it further includes a duct, wherein the stator assembly, the housing, the heat pipe structure, the rotor and the blades are all disposed within the duct.

[0022] An electric propulsion system includes a motor stator structure, a rotor, blades, and a duct. The motor stator structure is any of the aforementioned motor stator structures. The rotor is correspondingly arranged with the stator assembly. The rotor is connected to the blades and drives the blades to rotate. The stator assembly, the housing, the heat pipe structure, the rotor, and the blades are all located within the duct. The electric propulsion system provided by this invention has a stator assembly disposed inside the housing. The stator core of the stator assembly has a plurality of stator teeth on its inner circumference. Stator windings are disposed on the surface of the stator teeth. During motor operation, the stator windings generate heat. A heat pipe structure is disposed in a slot in the housing. The heat dissipation end of the heat pipe structure is located in the slot, and the heat absorption end of the heat pipe structure is located in the stator windings and is used to absorb heat. The absorbed heat is transferred to its heat dissipation end via the heat pipe structure. Combined with the heat dissipation fins on the surface of the housing, the heat dissipation effect can be improved. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 This is a structural schematic diagram of the stator assembly and housing assembly provided by the present invention;

[0025] Figure 2 This is a schematic diagram of the heat pipe structure provided by the present invention;

[0026] Figure 3 This is a structural schematic diagram of the stator assembly, housing, and heat pipe structure provided by the present invention.

[0027] Figure 4 This is a schematic diagram of the electric propulsion system provided by the present invention.

[0028] Figure label:

[0029] 1. Stator assembly; 2. Stator core; 3. Stator teeth; 4. Stator winding; 5. Housing; 6. Slot; 7. Heat pipe structure; 701. Annular tube; 702. Finned tube; 703. Right-angle tube; 8. Rotor; 9. Blade; 10. Slot wedge; 11. Duct. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The core of this invention is to provide an electric propulsion system with significantly improved heat dissipation.

[0032] It should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", "front", and "rear" is based on the orientation or positional relationship shown in the accompanying drawings and is only for the purpose of facilitating the description of this application and simplifying the description. It is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0033] This application provides an electric propulsion system, comprising: a stator assembly 1, a stator winding 4, a housing 5, a heat pipe structure 7, and a rotor 8;

[0034] Among them, the inner circumference of the stator core 2 of the stator assembly 1 is provided with a number of stator teeth 3;

[0035] Stator winding 4 is located on stator tooth 3;

[0036] The housing 5 has a tubular structure, the stator assembly 1 is located on the inner periphery of the housing 5, the housing 5 is provided with a slot 6, and the outer periphery surface of the housing 5 is provided with several heat dissipation fins.

[0037] The heat-absorbing end of the heat pipe structure 7 is located in the stator winding 4, and the heat-dissipating end of the heat pipe structure 7 is located in the slot 6 and cooperates with the heat dissipation fins to dissipate heat.

[0038] For details, please refer to the appendix. Figure 1 With appendix Figure 3The heat-absorbing end of the heat pipe structure 7 is directly located in the stator winding 4, and the heat-dissipating end is inserted into the slot 6 of the housing 5. This allows the heat generated by the stator winding 4 to be quickly transferred to the housing 5 through the heat pipe structure 7. The housing 5, acting as a heat sink, is located in the air duct and is efficiently cooled by the airflow passing through the duct 11 during aircraft operation, thereby significantly improving the heat dissipation capacity of the electric propulsion system. With good heat dissipation, the motor and controller can withstand higher current loads or maintain a smaller size, thereby increasing the power density of the system and meeting the high power output requirements of low-altitude electric vertical take-off and landing aircraft. By directing heat from the internal heat-generating components to the housing 5 through the heat pipe structure 7 and utilizing the airflow of the duct 11 for cooling, there is no need for additional water-cooling pipes or large cooling fans, simplifying the system structure and helping to further reduce the overall weight. In summary, this application integrates the stator assembly 1 and the heat pipe structure 7 into a compact design, which is conducive to reducing size and weight, optimizing installation space and wiring, and is suitable for low-altitude ducted EVTOL aircraft with strict space and weight requirements.

[0039] Based on the above embodiments, the heat pipe structure 7 includes an annular tube 701, a finned tube 702, and a right-angle tube 703. The annular tube 701 has a circular annular structure, the finned tube 702 has a cuboid structure, and the right-angle tube 703 has an L-shaped structure. Several finned tubes 702 are provided and evenly distributed on the outer periphery of the annular tube 701, and several right-angle tubes 703 are provided and evenly distributed on the inner periphery of the annular tube 701.

[0040] For details, please refer to the appendix. Figure 2 The annular tube 701 serves as the central connecting structure, connecting the inner right-angle tube 703 with the outer finned tube 702 to form a closed cooling medium circulation channel. The right-angle tube 703 is directly inserted into the stator core slot, i.e., in the gap between adjacent windings, and can absorb heat from the stator winding 4 where the heat is most concentrated. The heat is quickly transferred to the finned tube 702 through the annular tube 701, and then guided by the finned tube 702 to the housing 5 for dissipation, achieving efficient heat conduction from the heat source to the heat sink. Multiple right-angle tubes 703 are evenly distributed on the inner circumference of the annular tube 701 and can be inserted into different stator slots, thereby absorbing heat from multiple winding parts at the same time, avoiding local heat accumulation, making the internal temperature distribution of the stator more uniform, and improving the thermal reliability of the electric propulsion system. Multiple finned tubes 702 are evenly distributed on the outer circumference of the annular tube 701 and inserted into the slot 6 of the housing 5, serving as part of the heat dissipation fins. The cuboid structure of the finned tube 702 has a large surface area, which can significantly enhance the convective heat transfer effect under the action of ducted airflow, further improving the heat dissipation performance of the entire electric propulsion system.

[0041] Based on the above embodiments, the annular tube 701, the finned tube 702 and the right-angle tube 703 are all hollow structures, and the cavities of the annular tube 701, the finned tube 702 and the right-angle tube 703 are connected and combined to form a closed cavity, and a cooling medium is provided in the closed cavity.

[0042] Specifically, the closed cavity formed by the connection of the annular tube 701, finned tube 702, and right-angle tube 703 is filled with a cooling medium, such as a phase change working fluid. After the right-angle tube 703 absorbs heat from the stator winding 4, the cooling medium evaporates into a gas, carrying a large amount of latent heat of vaporization. The gas flows through the annular tube 701 to the finned tube 702, where it condenses into a liquid upon cooling, releasing heat. The liquid then flows back along the inner wall to the right-angle tube 703, forming a cycle. This process utilizes phase change heat transfer, and its thermal conductivity is much higher than that of ordinary metals, enabling rapid cooling of the stator winding 4. The generated heat is conducted to the heat dissipation surface of the casing 5; the cooling medium in the closed cavity completes the heat transfer by evaporation-condensation cycle, without the need for external pumps, fans or other active components, and without moving parts, avoiding mechanical failures and energy consumption, and improving the overall reliability of the electric propulsion system; since the working fluid in the heat pipe is approximately isothermal in the saturated state, the temperature distribution of the entire heat pipe structure 7 is very uniform. Even if the heat generation in different parts of the stator winding 4 is uneven, the heat pipe structure 7 can also diffuse the heat through the rapid phase change of the internal working fluid, effectively eliminating local overheating and extending the insulation life of the winding.

[0043] Based on the above embodiment, the first end of the right-angle tube 703 is connected to the annular tube 701, a stator slot is provided between adjacent stator teeth 3, and the second end of the right-angle tube 703 is located in the stator slot and between adjacent turns of the stator winding 4.

[0044] Specifically, the second end of the right-angle tube 703 extends directly between adjacent turns of the stator winding 4, making the heat-absorbing end of the heat pipe in close contact with the main heat source, the stator winding 4. Compared to arranging the heat pipe structure 7 on the outer surface of the stator core 2 or at a distance, this greatly shortens the path of heat transfer from the winding to the heat pipe, reduces the thermal resistance, and thus allows for faster and more effective absorption of the heat generated by the winding. Since there are natural gaps between the stator windings 4, inserting the right-angle tube 703 into them does not require additional axial or radial space and does not change the original layout of the stator core 2 and the windings. This helps maintain the overall compactness of the electric propulsion system and avoids increasing the volume or weight due to the addition of heat dissipation structures. Multiple right-angle tubes 703 are evenly distributed around the inner circumference of the annular tube 701 and inserted into different winding gaps, allowing for individual heat absorption for each winding segment. Even if some windings generate localized high temperatures due to high current density or poor ventilation, these temperatures can be quickly absorbed by the nearest right-angle tube 703, resulting in a more uniform temperature distribution inside the stator and improving the thermal reliability and lifespan of the motor.

[0045] Based on the above embodiments, the cooling medium is a phase change medium.

[0046] Specifically, the phase change medium changes from a liquid to a gaseous state when absorbing heat, absorbing a large amount of latent heat of vaporization; when releasing heat, it condenses from a gaseous state to a liquid state, releasing an equal amount of heat. The equivalent thermal conductivity of this phase change process is much higher than that of pure metals, which can quickly and efficiently transfer the heat generated by the stator windings to the heat dissipation surface of the casing, significantly improving the heat dissipation capacity of the electric propulsion system.

[0047] Based on the above embodiments, the cooling medium is water, and the inner walls of the annular tube 701, finned tube 702 and right-angle tube 703 are provided with anti-corrosion layers.

[0048] Specifically, the cooling medium is pure water, which will be referred to as water in the following text. Water, as a cooling medium, has the characteristics of high specific heat capacity and high latent heat of vaporization. When the heat pipe structure 7 is working, the water absorbs the heat of the winding in the right-angle tube 703 and quickly vaporizes into water vapor, carrying a large amount of heat to the finned tube 702. It condenses into water when it cools at the finned tube 702, releasing heat. The phase change heat transfer coefficient of water is much higher than that of ordinary metals, which can quickly conduct the heat generated by the stator winding to the casing, significantly improving the heat dissipation capacity of the electric propulsion system. The anti-corrosion layer can inhibit the dissolution of metal ions into the water, avoid the formation of precipitates or scale, reduce the risk of impurities clogging the tiny channels inside the heat pipe, ensure the free flow of the cooling medium and smooth phase change circulation, and maintain efficient heat transfer capacity.

[0049] Based on the above embodiment, the outer wall of the annular tube 701 abuts against the inner wall of the housing 5, the number of finned tubes 702 is the same as the number of slots 6 and is arranged accordingly, the finned tubes 702 are at least partially inserted into the slots 6 and cooperate with the inner wall of the slots 6 to transfer heat.

[0050] Specifically, the finned tubes 702 correspond one-to-one with the slots 6 and have matching thicknesses, while the annular tubes 701 match the inner circumference of the housing 5. This ensures that the heat pipe structure 7 is reliably positioned radially and circumferentially within the housing 5, preventing loosening or displacement due to vibration or airflow impact, and enhancing the structural reliability of the electric propulsion system under complex aircraft operating conditions. The number of finned tubes 702 is the same as the number of slots 6 and corresponds one-to-one, avoiding redundant or missing heat dissipation structures and ensuring that each slot 6 is effectively utilized. The outer diameter of the annular tubes 701 is consistent with the inner circumference of the housing 5, without generating excess gaps, maximizing the heat dissipation area within a limited space, while maintaining the compactness of the overall structure of the electric propulsion system.

[0051] In some embodiments, the stator winding 4 is fixed to the stator tooth 3 by a slot wedge 10, the stator tooth 3 is connected to the stator yoke by a dovetail key, and an insulating adhesive is provided between the heat pipe structure 7 and the stator assembly 1.

[0052] Specifically, the stator core 2 adopts a tooth-yoke separation structure. First, the stator winding 4 is fitted onto the independent stator tooth 3. Then, the slot wedge 10 is used to fix the stator winding 4 onto the stator tooth 3. Finally, the stator tooth 3 and the stator yoke are connected as a whole by a dovetail key. This step-by-step assembly method avoids the problem of difficult wire threading in the integral stator core 2, reduces the difficulty of winding insertion, and improves production efficiency and yield. The slot wedge 10 firmly presses the stator winding 4 into the stator tooth slot, effectively preventing the winding from loosening, displacing, or rubbing during motor operation or aircraft vibration, reducing the risk of winding insulation damage, and improving the reliability and lifespan of the electric propulsion system under complex operating conditions. The dovetail key connection is a classic mechanical interlocking structure that can withstand large torque and radial force. The stator teeth and stator yoke are precisely positioned circumferentially. Compared to relying solely on adhesive or interference fit, the dovetail key connection is more reliable, facilitates disassembly and maintenance, and prevents the stator teeth 3 from deflecting or shifting under electromagnetic force. The tooth-yoke separation structure provides more operating space for the gaps between the stator windings, making it easier to insert the right-angle tube 703 into the winding gaps. At the same time, the slot wedge 10 fixation does not occupy the heat dissipation path on the side of the windings. With the subsequent filling of potting compound, the windings can be fixed and heat can be smoothly conducted to the heat pipe. After the heat pipe structure 7 is installed, the stator assembly 1 is potted with potting compound to fill the gap between the heat pipe structure 7 and the stator winding 4, improve insulation performance, and further improve the heat transfer from the windings to the heat pipe through the potting compound.

[0053] In some embodiments, insulating paper is provided between the straight section of the stator winding 4 and the stator core 2, insulating end plates are provided between the two ends of the stator winding 4 and the stator core 2, and the outer wall of the stator core 2 is interference-fitted with the inner wall of the housing 5.

[0054] Specifically, insulating paper is placed between the straight section of the stator winding 4 and the stator core 2, and insulating end plates are placed between the two ends of the winding and the stator core 2, together forming a complete electrical isolation layer. This effectively avoids direct contact between the winding and the core, preventing short circuit accidents caused by insulation damage or high-voltage breakdown, and ensuring the safe operation of the electric propulsion system. The insulating paper and insulating end plates not only provide insulation but also limit the position of the winding during the potting process, preventing the winding from moving or shifting within the stator slots. Combined with the slot wedge 10 for fixation, this keeps the winding stable under vibration, reducing the risk of insulation wear. The interference fit ensures that the outer wall of the stator core 2 fits tightly against the inner wall of the housing 5, eliminating gaps and significantly reducing contact thermal resistance. The heat generated by the stator core 2, including the heat transferred from the winding to the core, can be quickly conducted to the housing 5. The housing then dissipates heat through ducted airflow, supplementing the path of direct heat conduction from the winding through the heat pipes, forming an auxiliary heat dissipation channel from the winding to the core and then to the housing, further improving the overall heat dissipation performance.

[0055] In addition to the above-mentioned motor stator structure, the present invention also provides an electric propulsion system including the motor stator structure disclosed in the above embodiments. The electric propulsion system further includes a rotor 8, a blade 9 and a duct 11. The rotor 8 is correspondingly arranged with the stator assembly 1. The rotor 8 is connected to the blade 9 and is used to drive the blade 9 to rotate. The stator assembly 1, the housing 5, the heat pipe structure 7, the rotor 8 and the blade 9 are all arranged in the duct 11.

[0056] For details, please refer to the appendix. Figure 4 Duct 11 is the main airflow channel during aircraft operation. The motor housing, the finned tubes 702 of the heat pipe structure 7, and the housing of the motor controller are all located in the airflow inside duct 11. When the aircraft is running, the high-speed gas flowing through the duct can directly wash these heat dissipation surfaces, achieving convective heat transfer and significantly improving heat dissipation efficiency without the need for additional cooling fans. By integrating duct 11, stator assembly 1, housing 5, heat pipe structure 7, rotor 8, and blades 9 all inside duct 11, an integrated electric propulsion system is formed. There is no need for external additional heat dissipation ducts or protective covers, which greatly reduces the system size and weight, optimizes installation space, and is particularly suitable for the stringent requirements of compact structure for low-altitude ducted EVTOL aircraft.

[0057] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0058] The electric propulsion system with a motor stator structure provided by the present invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. An electric machine stator structure, characterized by include: The stator assembly (1) has several stator teeth (3) on the inner circumference of its stator core (2); Stator winding (4) is provided on the stator teeth (3); The housing (5) is a tubular structure. The stator assembly (1) is located on the inner periphery of the housing (5). The housing (5) is provided with a slot (6). The outer periphery surface of the housing (5) is provided with several heat dissipation fins. The heat pipe structure (7) has its heat absorption end located in the stator winding (4) and its heat dissipation end located in the slot (6) and cooperates with the heat dissipation fins to dissipate heat.

2. The motor stator structure of claim 1, wherein The heat pipe structure (7) includes an annular tube (701), a finned tube (702), and a right-angle tube (703). The annular tube (701) is a circular annular structure, the finned tube (702) is a cuboid structure, and the right-angle tube (703) is an L-shaped structure. The finned tubes (702) are provided in a plurality of numbers and are evenly distributed on the outer periphery of the annular tube (701), and the right-angle tubes (703) are provided in a plurality of numbers and are evenly distributed on the inner periphery of the annular tube (701).

3. The motor stator structure of claim 2, wherein The annular tube (701), the finned tube (702), and the right-angle tube (703) are all hollow structures, and the cavities of the annular tube (701), the finned tube (702), and the right-angle tube (703) are connected and combined to form a closed cavity, and a cooling medium is provided in the closed cavity.

4. The motor stator structure of claim 3, wherein The first end of the right-angle tube (703) is connected to the annular tube (701), and a stator slot is provided between adjacent stator teeth (3). The second end of the right-angle tube (703) is located in the stator slot and between adjacent turns of the stator winding (4).

5. The motor stator structure of claim 4, wherein The cooling medium is a phase change cooling medium.

6. The motor stator structure according to claim 4, characterized in that, The cooling medium is water, and the inner walls of the annular tube (701), the finned tube (702), and the right-angle tube (703) are provided with an anti-corrosion layer.

7. The motor stator structure according to claim 5, characterized in that, The outer wall of the annular tube (701) abuts against the inner wall of the housing (5). The number of finned tubes (702) is the same as the number of slots (6) and they are arranged accordingly. The finned tubes (702) are at least partially inserted into the slots (6) and cooperate with the inner wall of the slots (6) to transfer heat.

8. The motor stator structure according to claim 1, characterized in that, The stator winding (4) is fixed to the stator tooth (3) by a slot wedge (10), the stator tooth (3) is connected to the stator yoke by a pigeon tail key, and an insulating adhesive is provided between the heat pipe structure (7) and the stator assembly (1).

9. The motor stator structure according to claim 1, characterized in that, Insulating paper is provided between the straight section of the stator winding (4) and the stator core (2), and insulating end plates are provided between the two ends of the stator winding (4) and the stator core (2). The outer wall of the stator core (2) is interference-fitted with the inner wall of the housing (5).

10. An electric propulsion system, comprising a motor stator structure, a rotor (8), blades (9), and a duct (11), characterized in that, The motor stator structure is the motor stator structure as described in any one of claims 1 to 9. The rotor (8) is correspondingly arranged with the stator assembly (1). The rotor (8) is connected to the blade (9) and is used to drive the blade (9) to rotate. The stator assembly (1), the housing (5), the heat pipe structure (7), the rotor (8) and the blade (9) are all located in the duct (11).

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