Stator fixing and cooling structure for electric drive of aircraft

Abstract

The utility model relates to a kind of stator fixing and cooling structure for aircraft electric drive, including stator shell, winding and sealing cover, the winding is arranged in stator shell outer wall, the lower portion of stator shell located winding is also provided with outer edge, the sealing cover is buckled in winding outside, and upper and lower end is respectively fixed with stator shell top and outer edge, so that cooling cavity is formed between stator shell and sealing cover, the inner of the cooling cavity is also provided with oil inlet hole and oil outlet hole.The utility model constructs a sealed cooling cavity wrapped in the outside of winding, realizes high-efficiency direct oil cooling;Cooling oil (or other medium) can be directly injected into the cavity, and directly contact heat exchange with the winding that generates main heat in large area, zero distance.This compares with the mode of traditional machine shell external water cooling, greatly shortens heat conduction path, significantly reduces thermal resistance, thereby realizes extremely high cooling efficiency, can effectively cope with the violent temperature rise generated by aircraft electric drive instantaneous high-power operation.

Description

Technical Field

[0001] This utility model relates to the field of aircraft motor structure technology, and in particular to a stator fixing and cooling structure for aircraft electric drive. Background Technology

[0002] Aircraft, especially advanced aircraft such as electric vertical takeoff and landing (eVTOL) aircraft and unmanned aerial vehicles (UAVs), face extremely stringent requirements regarding the power density, reliability, and lightweight design of their propulsion systems. As the core power source of an aircraft, the performance of the electric drive system directly determines its payload, range, and safety. Within an electric drive system, the stator, as a critical component for energy conversion, generates significant Joule heat and iron losses during operation, leading to a rapid increase in winding temperature. Excessive temperature rise accelerates the aging of insulation materials, reduces magnet performance, and can even cause motor demagnetization or burnout, seriously threatening flight safety. Therefore, efficient and reliable stator cooling technology has become one of the key bottlenecks in improving the performance of aircraft electric drive systems.

[0003] Currently, common motor cooling methods include air cooling and liquid cooling. Air cooling is simple in structure and lightweight, but its heat dissipation efficiency is limited, making it difficult to meet the huge heat dissipation requirements of high-power-density aircraft electric drive systems within a compact space. Liquid cooling, especially oil cooling, has become the preferred solution for high-power motors due to its higher specific heat capacity and thermal conductivity.

[0004] However, applying traditional liquid cooling technology to the stator of an aircraft electric drive system faces numerous challenges: 1. The conflict between structure and weight: Aircraft are extremely sensitive to weight. Traditional liquid cooling solutions often require the addition of complex water jackets or oil channels to the outside of the stator. These structures are usually made of metal (such as aluminum alloys), which, while ensuring structural strength, significantly increases the overall weight and volume of the system, hindering power density improvement. 2. Cooling uniformity and efficiency issues: Many existing designs place cooling channels far from the heat source of the windings. Heat needs to pass through multiple layers before being carried away by the cooling medium, resulting in high thermal resistance and low cooling efficiency. Furthermore, if the channel design is unreasonable, cooling dead zones can easily form, leading to localized overheating of the stator and affecting motor life and performance stability. 3. Process complexity and cost: Complex cooling channel structures are often accompanied by complex manufacturing processes (such as welding, brazing, or multi-component assembly), which not only increases manufacturing costs but also introduces more potential failure points. Utility Model Content

[0005] To address the aforementioned technical problems, the present invention aims to provide a stator fixing and cooling structure for electric drive systems of aircraft. This structure achieves efficient and uniform heat dissipation while ensuring structural strength and reliable sealing, and also features high integration and lightweight characteristics.

[0006] To achieve the above-mentioned objectives, this utility model adopts the following technical solution:

[0007] A stator fixing and cooling structure for an aircraft electric drive includes a stator housing, windings, and a sealing cover. The windings are disposed on the outer wall of the stator housing. The stator housing is located below the windings and has an outer edge. The sealing cover is fastened to the outside of the windings, and its upper and lower ends are respectively fixed to the top and outer edge of the stator housing, so that a cooling cavity is formed between the stator housing and the sealing cover. The cooling cavity is also provided with an oil inlet and an oil outlet.

[0008] As a preferred embodiment, the outer edge of the stator housing is provided with a plurality of cooling grooves surrounded by protruding ridges, and the lower part of the sealing cover is provided with a flange, which is fixed to the outer edge and located outside the cooling grooves.

[0009] As a preferred embodiment, at least one of the cooling grooves is provided with an oil outlet hole, and the oil outlet hole is offset from the oil inlet hole.

[0010] As a preferred embodiment, the inner wall of the stator housing is provided with an internal integrated oil pipe, the oil inlet is opened on the side wall of the stator housing, and the upper middle part of the internal integrated oil pipe is connected to the cooling cavity through the oil inlet.

[0011] As a preferred embodiment, a through hole A is provided on the side wall of the stator housing, the three-phase lead wires of the winding pass through the through hole A, and a sealing plug ring is provided between them and the through hole A.

[0012] As a preferred embodiment, the three-phase leads of the winding located inside the stator housing are also provided with copper lugs for easy wiring.

[0013] As a preferred embodiment, the sealing cover is made of carbon fiber and has a raised ring on the top to avoid the winding.

[0014] As a preferred embodiment, the inner end face of the stator housing is provided with multiple internal reinforcing ribs in a radial pattern.

[0015] As a preferred embodiment, multiple fixing posts are arranged at intervals along the circumference of the stator housing located at the lower part of the outer edge.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] This invention constructs a sealed cooling cavity encasing the windings, achieving highly efficient direct oil cooling. Cooling oil (or other media) can be directly injected into this cavity, allowing for large-area, zero-distance direct heat exchange with the windings, which generate the main heat. Compared to traditional external water cooling, this significantly shortens the heat conduction path and reduces thermal resistance, thereby achieving extremely high cooling efficiency and effectively coping with the drastic temperature rise generated by the instantaneous high-power operation of the aircraft's electric drive.

[0018] In addition, the sealing cover, fixed to the top and outer edge of the stator housing, forms a closed environment. This not only accommodates the cooling oil but also effectively prevents external dust, moisture, and other contaminants from entering, protecting the windings and insulation system and improving the reliability of the motor in complex environments.

[0019] This invention also integrates the cooling function with the fixed support structure of the stator (stator housing), avoiding the need for additional bulky cooling jackets or complex external piping. This integrated cooling structure design meets the aircraft's extreme pursuit of high power density and lightweight, reducing system weight while ensuring strength. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation thereof.

[0021] Figure 1 This is a schematic diagram of the overall structure of the motor using the structure of this utility model;

[0022] Figure 2 This is an exploded view of a motor using the structure of this utility model (the radiator assembly is not shown).

[0023] Figure 3 and Figure 4 These are schematic diagrams of the electronic housing and windings at two different angles of this utility model;

[0024] Figure 5 This is a schematic diagram of the stator housing of this utility model;

[0025] Figure 6 This is a cross-sectional structural diagram of the present invention.

[0026] The reference numerals in the accompanying drawings are as follows: 1. Outer rotor assembly; 110. Bearing outer ring pressure plate; 2. Stator assembly; 210. Bearing inner ring pressure plate; 220. Power connector; 21. Stator housing; 211. Lug; 212. Mounting groove; 213. Cooling groove; 214. Through hole A; 215. Internal integrated oil pipe; 2151. Oil inlet; 217. Internal reinforcing rib; 218. Oil outlet; 219. Fixing post; 22. Winding; 221. Copper lug; 222. Sealing plug ring; 3. Radiator assembly; 5. Sealing cover. Detailed Implementation

[0027] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0028] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] Furthermore, in the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. 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.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, unless otherwise expressly defined.

[0031] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0032] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0034] like Figure 1 The aircraft motor shown includes an outer rotor assembly 1, a stator assembly 2, a controller assembly, and a heat sink assembly 3. The outer rotor assembly 1 is rotatably connected to the stator assembly 2 via a bearing 6. The outer rotor assembly 1 and the stator assembly 2 are respectively provided with an inner bearing ring pressure plate 210 and an outer bearing ring pressure plate 110 for limiting the bearing 6. The stator assembly 2 includes a stator housing 21 and a winding 22 disposed on the outer wall of the stator housing 21. A sealing cover 5 is fixed to the outside of the winding 22. A base plate 20 is fixed to the bottom of the stator housing 21. The controller assembly is disposed in the mounting cavity formed by the stator housing 21 and the base plate 20. The heat sink assembly 3 is fixed to the lower part of the base plate 20.

[0035] like Figures 2 to 6 As shown, the stator housing 21 is located at the lower part of the winding 22 and has an outer edge. The sealing cover 5 is fastened to the outside of the winding 22, and its upper and lower ends are fixed to the top and outer edge of the stator housing 21, respectively, so that a cooling cavity is formed between the stator housing 21 and the sealing cover 5. The cooling cavity is also provided with an oil inlet hole 2151 and an oil outlet hole 218.

[0036] The stator housing 21 has multiple cooling grooves 213 enclosed by protruding ridges on its outer edge. The lower part of the sealing cover 5 has a flange, which is fixed to the outer edge and located outside the cooling grooves 213. The structure of the protruding ridges and cooling grooves forms a series of pre-set flow channels at the bottom of the cooling chamber. These flow channels guide the cooling oil to flow preferentially and orderly through these grooves, avoiding eddies or dead zones that may be generated by the oil flowing randomly at the bottom, and ensuring the uniformity of coolant distribution.

[0037] Meanwhile, the raised ribs act as reinforcing ribs, enhancing the structural rigidity and mechanical strength of the outer edge of the stator housing bottom to withstand vibrations and loads during flight. Simultaneously, the grooved structure increases the contact surface area with the cooling oil, further improving heat exchange efficiency. Furthermore, the raised ribs provide a clear and flat sealing surface for the flange of the sealing cover, facilitating uniform pressure application of the gasket or sealant and ensuring reliable sealing at the bottom connection.

[0038] At least one of the cooling grooves 213 of the stator housing 21 is provided with an oil outlet 218, which is offset from the oil inlet 2151. This offset arrangement of the inlet and outlet forces the cooling oil, after flowing in from the inlet, to not flow directly to the outlet via a "short-circuit," but instead to flow around and fill the entire cooling chamber, especially through the main heat-generating areas around the windings. This design greatly extends the residence time of the cooling oil in the effective heat exchange area, ensuring that heat is fully carried away, eliminating cooling dead zones, and achieving uniform and efficient overall cooling.

[0039] The stator housing 21 has an internally integrated oil pipe 215 on its inner wall. An oil inlet 2151 is located on the side wall of the stator housing 21, and the upper middle part of the internally integrated oil pipe 215 communicates with the cooling chamber through the oil inlet 2151. The internally integrated oil pipe allows cooling oil to enter from the oil inlet on the upper side wall of the stator housing. This allows the cooling oil to be sprayed or guided directly towards the winding ends (typically one of the hottest parts of the motor), achieving priority and efficient cooling of the hottest spots and optimizing the cooling strategy. Furthermore, integrating the oil pipe into the inner wall of the housing allows for a more rational placement of the external oil inlet, reducing complex and messy external piping connections, making the overall system structure more compact, and facilitating installation within the confined space of an aircraft.

[0040] A through hole A214 is provided on the side wall of the stator housing 21. The three-phase leads of the winding 22 pass through the through hole A214, and a sealing ring 222 is provided between them and the through hole A214. Using a custom-made sealing ring (typically made of an oil-resistant, high-temperature-resistant elastic material such as fluororubber), a reliable static seal can be formed between the conductor and the housing hole wall, effectively preventing oil leakage from the cooling chamber. The sealing ring also serves to fix and insulate, preventing the conductor from rubbing against the metal hole wall and damaging the insulation layer, thus improving electrical safety.

[0041] The winding 22, located inside the stator housing 21, is equipped with copper lugs 221 on its three-phase leads for easy wiring. These copper lugs provide standardized and robust terminals. In situations where the internal space of the motor is limited, copper lugs allow for quick, reliable, and low-resistance connections to external cables via bolts or welding, ensuring the stability of high-current transmission.

[0042] The sealing cover 5 is made of carbon fiber and has a raised ring on top to avoid the winding 22. Carbon fiber has extremely high specific strength and specific modulus. Using it to manufacture the sealing cover can significantly reduce the weight of the component. The raised ring design on the top provides the necessary space to accommodate the end of the internal winding (especially the part that protrudes above the stator core), avoiding interference between the sealing cover and the winding and ensuring the rationality of the structure.

[0043] The stator housing 21 has multiple radially arranged inner reinforcing ribs 217 on its inner end face. The inner end face is the main part of the stator that bears electromagnetic torque and vibration. The radially arranged inner reinforcing ribs can significantly improve the bending and torsional stiffness of this part, prevent the housing from deforming under complex loads, ensure the uniformity of the motor air gap, thereby ensuring stable motor performance and reducing noise and vibration.

[0044] In addition, multiple fixing posts 219 are arranged at circumferential intervals along the lower part of the stator housing 21 located on the outer edge. These fixing posts constitute the main mechanical connection points between the motor and adjacent components such as the aircraft body or gearbox. The circumferentially spaced arrangement can achieve uniform force transmission and balance, ensuring that the motor can be firmly fixed and prevent loosening when the aircraft experiences various attitudes and accelerations.

[0045] This utility model discloses an efficient, reliable, lightweight and compact structure for fixing and cooling an electric drive stator for aircraft, which solves many of the problems mentioned in the background art.

[0046] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A stator fixing and cooling structure for an aircraft electric drive system, characterized in that, The stator housing (21), winding (22) and sealing cover (5) are included. The winding (22) is disposed on the outer wall of the stator housing (21). The stator housing (21) is located at the lower part of the winding (22) and has an outer edge. The sealing cover (5) is fastened to the outside of the winding (22) and its upper and lower ends are fixed to the top and outer edge of the stator housing (21) respectively, so that a cooling cavity is formed between the stator housing (21) and the sealing cover (5). An oil inlet hole (2151) and an oil outlet hole (218) are also provided in the cooling cavity.

2. The stator fixing and cooling structure for an aircraft electric drive according to claim 1, characterized in that, The stator housing (21) has a plurality of cooling grooves (213) surrounded by protruding ridges on its outer edge. The lower part of the sealing cover (5) has a flange, which is fixed to the outer edge and located outside the cooling grooves (213).

3. The stator fixing and cooling structure for an aircraft electric drive according to claim 2, characterized in that, At least one of the cooling grooves (213) is provided with an oil outlet (218), and the oil outlet (218) is offset from the oil inlet (2151).

4. The stator fixing and cooling structure for an aircraft electric drive according to claim 1, characterized in that, The inner wall of the stator housing (21) is provided with an internal integrated oil pipe (215), and the oil inlet (2151) is opened on the side wall of the stator housing (21). The upper middle part of the internal integrated oil pipe (215) is connected to the cooling cavity through the oil inlet (2151).

5. The stator fixing and cooling structure for an aircraft electric drive according to claim 1, characterized in that, A through hole A (214) is provided on the side wall of the stator housing (21), and the three-phase lead wires of the winding (22) pass through the through hole A (214), and a sealing plug ring (222) is provided between the winding (22) and the through hole A (214).

6. The stator fixing and cooling structure for an aircraft electric drive according to claim 1, characterized in that, The winding (22) is provided with copper lugs (221) on the three-phase lead wires inside the stator housing (21) for easy wiring.

7. The stator fixing and cooling structure for an aircraft electric drive according to claim 1, characterized in that, The sealing cover (5) is made of carbon fiber and has a raised ring on the top to avoid the winding (22).

8. The stator fixing and cooling structure for an aircraft electric drive according to claim 1, characterized in that, The inner end face of the stator housing (21) is provided with multiple inner reinforcing ribs (217) in a radial pattern.

9. The stator fixing and cooling structure for an aircraft electric drive according to claim 1, characterized in that, Multiple fixing posts (219) are arranged at intervals along the circumference of the lower part of the stator housing (21) located on the outer edge.

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