Integrated outer rotor oil pump fan cooling system in eVTOL propulsion motor

Abstract

The invention relates to an integrated outer rotor oil pump fan cooling system in an eVTOL propulsion motor, and relates to the field of gas-liquid self-circulation cooling of electric propulsion motors. According to the technical scheme, the structure is highly integrated, the fan blades and the outer rotor of the motor are integrally designed, the oil pump is integrated in the heat dissipation machine shell, the outer rotor, the driving shaft and the inner rotor of the oil pump are coaxially arranged, an intermediate transmission mechanism is omitted, the installation space is greatly reduced, and the transmission efficiency is remarkably improved. Moreover, through cooperation of air cooling and liquid cooling, a fan synchronously rotates along with an outer rotor to strengthen heat exchange of an external propulsion motor, oil liquid directly reaches a motor armature through a closed-loop path to scour and absorb heat, a high-pressure oil channel and a heat dissipation oil through hole ensure directional conveying and smooth backflow of the oil liquid, and efficient heat dissipation is achieved. In addition, the static seal at the oil separation cover and the dynamic seal between the outer rotor and the rear end cover can prevent oil leakage and prevent external impurities from invading, and the all-directional GeVTOL propulsion motor meets the requirements for light weight, efficient heat dissipation and high reliability.

Description

Technical Field

[0001] This invention relates to the field of gas-liquid self-circulating cooling technology for electric propulsion motors, and particularly to an integrated external rotor oil pump fan cooling system in an eVTOL propulsion motor. Background Technology

[0002] In recent years, electric vertical takeoff and landing (eVTOL) aircraft have continued to develop rapidly. As the core component of their drive system, the propulsion motor is directly related to the aircraft's flight safety, endurance, and operational stability. Therefore, the industry has placed more stringent requirements on the various technical characteristics of propulsion motors. Among these, the cooling system, as a key link to ensure the long-term efficient operation of the propulsion motor, has particularly prominent requirements for high-efficiency heat dissipation, highly integrated structure, and high operational reliability, becoming one of the important factors restricting the performance improvement of eVTOL propulsion motors.

[0003] In traditional liquid-cooled propulsion motor circulation cooling technology, a decentralized architecture is commonly used, employing independent oil pumps, independent fans, and even external coolers. The independent oil pumps drive the circulation of cooling oil, the independent fans provide auxiliary heat dissipation, and the external coolers are used to cool the oil. This architecture not only results in a dispersed overall cooling system structure and complex piping layout, but also leads to a larger system size and increased weight. Furthermore, the power transmission between multiple components relies on intermediate mechanisms, which easily leads to energy loss and low transmission efficiency, making it difficult to meet the core requirements of eVTOL propulsion motors for lightweight internal components and space-efficient design. In contrast, external rotor motors, with their compact structure and excellent heat dissipation performance, have been gradually adopted in equipment such as fans and pumps, providing a technological direction for solving the shortcomings of traditional cooling systems.

[0004] Therefore, there is an urgent need for an integrated oil pump and fan cooling system based on an external rotor configuration. Through the integrated optimization of structure and function, the system can be made compact, the transmission can be made efficient, and the operation can be made reliable, so as to meet the dual requirements of eVTOL propulsion motor for efficient cooling and space optimization. Summary of the Invention

[0005] The purpose of this invention is to provide an integrated external rotor oil pump fan cooling system within an eVTOL propulsion motor to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An integrated external rotor oil pump fan cooling system within an eVTOL propulsion motor includes: The motor has an outer rotor with magnets installed on its inner side and fan blades integrated on its outer surface. It is connected to the rear end cover to form an installation cavity. The front end cover is located inside the mounting cavity. After being connected to the heat sink housing, it can press and fix the motor armature to the inside of both. The heat sink housing has an oil pump cavity on the side near the rear end cover, and the outer rotor of the oil pump is movably disposed in the oil pump cavity. The drive shaft is rotatably connected to the inner hole of the front end cover and the heat sink housing via bearings. Its first end is connected to the center of the outer rotor of the motor. Its rotational power is provided by the electromagnetic action generated by the motor armature and the magnet. An inner rotor of the oil pump is disposed inside the outer rotor of the oil pump and meshes with the outer rotor of the oil pump to form a gear pump structure. The inner rotor of the oil pump is sleeved on the second end of the drive shaft. The heat sink housing is also provided with an embedded cooling channel. The output oil channel of the gear pump structure is connected to the motor cavity where the motor armature is located. The motor cavity is connected to the output end of the rear cover, so that the oil can be output from the motor cavity to the outside.

[0007] In some embodiments, an oil separator is also provided at the connection between the front end cover and the heat sink housing. The oil separator achieves internal sealing of the motor cavity through static sealing, preventing leakage of internal fluids when passing through the motor armature.

[0008] In some embodiments, when the outer rotor of the motor rotates, the magnet is limited by a magnet baffle to prevent the magnet from being thrown out. The magnet baffle is connected to the outer rotor of the motor by bolts.

[0009] In some embodiments, a dynamic seal is provided at the connection between the outer rotor of the motor and the rear end cover to prevent external media from entering the mounting cavity.

[0010] In some embodiments, the front cover is connected to the heat sink housing by bolts, and the connection between the front cover and the heat sink housing is provided with a stop and a sealing groove; The heat sink housing is connected to the rear end cover by bolts.

[0011] In some embodiments, the heat sink housing is further provided with a high-pressure oil channel and a heat dissipation oil passage; One end of the high-pressure oil channel is connected to the oil outlet of the gear pump structure, and the other end is connected to the motor cavity, so that the high-pressure oil discharged from the gear pump structure can enter the motor cavity through the high-pressure oil channel; One end of the heat dissipation oil vent is connected to the motor cavity, and the other end is connected to the oil trough inside the rear end cover, so that the oil in the motor cavity can flow back to the oil trough inside the rear end cover through the heat dissipation oil vent.

[0012] In some embodiments, the end face of the rear end cover is provided with a low-pressure oil inlet and a high-pressure oil inlet, and the interior of the rear end cover is provided with a low-pressure oil chamber and an annular oil groove. The low-pressure oil inlet is connected to the low-pressure oil chamber, and the low-pressure oil from the external propulsion motor oil circuit can enter the low-pressure oil chamber through the low-pressure oil inlet, and then enter the oil pump cavity where the gear pump structure is located through the low-pressure oil chamber. The annular oil groove is connected to the heat dissipation oil passage and the high-pressure oil passage interface. The oil flowing back to the rear end cover oil groove can be output from the high-pressure oil passage interface to the external propulsion motor oil circuit through the annular oil groove. The low-pressure oil inlet is equipped with a stop and a sealing groove to improve the sealing performance when connected to the external propulsion motor oil circuit.

[0013] In some embodiments, the end face of the rear cover is provided with a low-voltage socket mounting hole and a high-voltage socket mounting hole; The heat dissipation oil passage of the heat dissipation housing and the annular oil groove of the rear end cover have functional reusability. The low-voltage and high-voltage cables at the end of the motor armature can pass through the heat dissipation oil passage into the annular oil groove, and then connect to the external low-voltage and high-voltage sockets through the low-voltage socket mounting hole and the high-voltage socket mounting hole.

[0014] In some embodiments, the internal rotor of the oil pump is connected to the drive shaft via a key to achieve torque transmission between the drive shaft and the internal rotor of the oil pump; When the drive shaft drives the inner rotor of the oil pump to rotate, the inner rotor of the oil pump gradually disengages from the suction side of the outer rotor of the oil pump, increasing the volume of the suction side and creating a partial vacuum, which draws the low-pressure oil in the low-pressure oil chamber into the oil pump cavity. As the drive shaft continues to rotate, the oil-filled toothed groove is brought to the discharge side, and the inner rotor of the oil pump and the outer rotor of the oil pump gradually enter a meshing state. The discharge side volume of the inner rotor of the oil pump and the outer rotor of the oil pump decreases, and the oil is pressurized and discharged through the high-pressure oil inlet.

[0015] In some implementations, the oil circulation path includes: Low-pressure oil from the external propulsion motor oil circuit → low-pressure oil inlet of the rear end cover → low-pressure oil chamber of the rear end cover → oil pump chamber where the gear pump structure is located. Low-pressure oil is pressurized into high-pressure oil in the oil pump cavity through the gear pump structure → high-pressure oil channel of the heat sink housing → motor cavity, to liquid cool the motor armature; The liquid-cooled oil flows through the heat dissipation oil vents of the heat dissipation housing, the annular oil groove of the rear end cover, the high-pressure oil inlet of the rear end cover, and the oil circuit of the external propulsion motor.

[0016] The beneficial effects of the technical solution provided by this invention include at least the following: This technical solution features a highly integrated structure, with the fan blades and the outer rotor of the motor integrated into one unit, and the oil pump integrated within the heat sink housing. Furthermore, the outer rotor, drive shaft, and inner rotor of the oil pump are coaxially arranged, eliminating intermediate transmission mechanisms, significantly reducing installation space, improving space utilization, avoiding transmission losses, and substantially increasing transmission efficiency. Moreover, it boasts outstanding heat dissipation efficiency. Through the synergy of air cooling and liquid cooling, the fan rotates synchronously with the outer rotor to enhance heat exchange with the external propulsion motor. The oil flows directly to the motor armature via a closed-loop path to flush and absorb heat. High-pressure oil channels and heat dissipation vents ensure directional oil delivery and smooth return, achieving highly efficient heat dissipation. In addition, it offers reliable and stable operation. The static seal at the oil separator and the dynamic seal between the outer rotor and the rear end cover prevent oil leakage and block external impurities from entering. The multifunctional heat dissipation vents and annular oil grooves allow for cable routing without interfering with oil circulation, comprehensively meeting the eVTOL propulsion motor's requirements for lightweight design, efficient heat dissipation, and high reliability. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0018] Figure 1 A schematic diagram of the layout of an integrated external rotor oil pump fan cooling system within an eVTOL propulsion motor provided in an exemplary embodiment of the present invention is shown.

[0019] Figure 2 A cross-sectional schematic diagram of an integrated external rotor oil pump fan cooling system within an eVTOL propulsion motor, provided by an exemplary embodiment of the present invention, is shown.

[0020] Figure 3 An exploded schematic diagram of an integrated external rotor oil pump fan cooling system within an eVTOL propulsion motor provided by an exemplary embodiment of the present invention is shown.

[0021] Figure 4 A schematic diagram of the structure of the external rotor of the eVTOL propulsion motor with an integrated external rotor oil pump fan cooling system provided in an exemplary embodiment of the present invention is shown.

[0022] Figure 5 A schematic diagram of the gear pump structure of an integrated external rotor oil pump fan cooling system in an eVTOL propulsion motor provided by an exemplary embodiment of the present invention is shown.

[0023] Figure 6 A schematic diagram of the oil circuit path of an integrated external rotor oil pump fan cooling system in an eVTOL propulsion motor provided by an exemplary embodiment of the present invention is shown.

[0024] In the picture: 1. Rotor housing; 2. Drive shaft; 3. Front cover; 4. Motor armature; 5. Oil separator cover; 6. Heat dissipation casing; 7. Internal rotor of the oil pump; 8. External rotor of the oil pump; 9. Rear end cover; 10. Bearings; 11. Magnetic steel baffle. Detailed Implementation

[0025] 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.

[0026] In this specification, identical components are represented by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, while the terms "bottom surface," "top surface," "inner," and "outer" refer to directions towards or away from a specific component. 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 indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this specification, "multiple" means two or more.

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] See Figures 1 to 4The integrated external rotor oil pump fan cooling system in the eVTOL propulsion motor includes: an external rotor 1, with magnets installed on its inner side and fan blades integrated on its outer surface, which is connected to the rear end cover 9 to form a mounting cavity; a front end cover 3, located within the mounting cavity, which, after being connected to the heat sink housing 6, can press and fix the motor armature 4 to the inner side of both; an oil pump cavity is opened on the side of the heat sink housing 6 near the rear end cover 9, and the external rotor 8 of the oil pump is movably disposed within the oil pump cavity; and a drive shaft 2, which is connected to the front end cover 3 and the inner hole of the heat sink housing 6 through a bearing 10. The rotating connection has its first end connected to the center of the outer rotor 1 of the motor, and its rotational power is provided by the electromagnetic action generated by the motor armature 4 and the magnet; the inner rotor 7 of the oil pump is located inside the outer rotor 8 of the oil pump and meshes with the outer rotor 8 of the oil pump to form a gear pump structure, and the inner rotor 7 of the oil pump is sleeved on the second end of the drive shaft 2; the heat sink housing 6 is also provided with an embedded cooling channel, the output oil channel of the gear pump structure is connected to the motor cavity where the motor armature 4 is located, and the motor cavity is connected to the output end of the rear cover 9, so that the oil can be output from the motor cavity to the outside.

[0029] In this embodiment, the inner magnets of the outer rotor of the motor work with the motor armature to generate electromagnetic driving force. The integrated fan blades on the outer surface eliminate the need for a separate fan, directly utilizing the rotor rotation to output airflow and reduce space occupation. The front cover and heat sink housing are combined to fix the motor armature, ensuring the stability of the electromagnetic action and providing a mounting base for the oil pump cavity, achieving structural compactness. The drive shaft is positioned by bearings, with both ends linked to the outer rotor and the inner rotor of the oil pump, respectively, so that the electromagnetic force synchronously drives the air cooling and oil pump operation, reducing transmission losses. The gear pump structure is connected to the embedded flow channel and oil passage, constructing an oil circulation path, allowing the oil to directly act on the armature for heat dissipation. Combined with the fan, the cooling efficiency is enhanced, adapting to the dual requirements of eVTOL for space and heat dissipation.

[0030] For details, please refer to Figures 1 to 3 An oil separator 5 is fitted at the connection between the front cover 3 and the heat sink housing 6. The oil separator 5 achieves internal sealing of the motor cavity through static sealing, preventing leakage of internal fluids when passing through the motor armature 4. When the outer rotor 1 of the motor rotates, the magnet is limited by the magnet baffle 11 to prevent the magnet from being thrown out. The magnet baffle 11 is connected to the outer rotor 1 of the motor by bolts. A dynamic seal is provided at the connection between the outer rotor 1 of the motor and the rear cover 9 to prevent external media from entering the installation cavity.

[0031] In this embodiment, the oil separator combined with a static seal not only prevents fluid leakage from the motor cavity along the motor armature but also maintains a sealed environment within the motor cavity, ensuring stable pressure for oil circulation and preventing reduced heat dissipation efficiency due to leakage. The magnet baffle, secured with bolts, firmly limits the magnet's position during high-speed rotation of the outer rotor, preventing it from being thrown out by centrifugal force and avoiding displacement that could disrupt the electromagnetic drive balance, thus ensuring stable power output from the drive shaft. The dynamic seal between the outer rotor and the rear end cover prevents external dust, moisture, and other impurities from entering the mounting cavity, while also preventing oil mist from overflowing and protecting internal bearings, gears, and other precision components from contamination.

[0032] For more details, see [link to relevant documentation]. Figures 1 to 6 The front cover 3 is bolted to the heat sink housing 6, and the connection between the front cover 3 and the heat sink housing 6 is provided with a stop and a sealing groove; the heat sink housing 6 is bolted to the rear cover 9. The heat sink housing 6 is also provided with a high-pressure oil channel and a heat dissipation oil passage; one end of the high-pressure oil channel is connected to the oil outlet of the gear pump structure, and the other end is connected to the motor cavity, so that the high-pressure oil discharged by the gear pump structure can enter the motor cavity through the high-pressure oil channel; one end of the heat dissipation oil passage is connected to the motor cavity, and the other end is connected to the oil groove inside the rear cover 9, so that the oil in the motor cavity can flow back to the oil groove of the rear cover 9 through the heat dissipation oil passage.

[0033] In this embodiment, the high-pressure oil channel inside the heat sink housing can directionally deliver the oil pressurized by the gear pump structure to the motor cavity, ensuring that the oil directly acts on the heated motor armature to achieve efficient cooling; the heat dissipation oil passage establishes a return path for the oil after heat absorption, allowing the oil that has completed its cooling task to flow smoothly back to the annular oil groove of the rear end cover. The two work together to form a complete oil circulation link.

[0034] Specifically, see Figures 1 to 6 The end face of the rear cover 9 is provided with a low-pressure oil inlet and a high-pressure oil inlet. The interior of the rear cover 9 is provided with a low-pressure oil chamber and an annular oil groove. The low-pressure oil inlet is connected to the low-pressure oil chamber, and the low-pressure oil from the external propulsion motor oil circuit can enter the low-pressure oil chamber through the low-pressure oil inlet, and then enter the oil pump cavity where the gear pump structure is located. The annular oil groove is connected to the heat dissipation oil inlet and the high-pressure oil inlet. The oil flowing back to the oil groove of the rear cover 9 can be output from the high-pressure oil inlet to the external propulsion motor oil circuit through the annular oil groove. The interface of the low-pressure oil inlet is provided with a stop and a sealing groove to improve the sealing performance when connected to the external propulsion motor oil circuit. The end face of the rear cover 9 is provided with a low-voltage socket mounting hole and a high-voltage socket mounting hole; the heat dissipation oil passage of the heat dissipation housing 6 and the annular oil groove of the rear cover 9 have functional reusability. The low-voltage cable and the high-voltage cable at the end of the motor armature 4 can pass through the heat dissipation oil passage to the annular oil groove, and then connect to the external low-voltage socket and high-voltage socket after passing through the low-voltage socket mounting hole and the high-voltage socket mounting hole.

[0035] In this embodiment, the low-pressure oil chamber buffers externally input low-pressure oil, preventing oil impact from affecting the gear pump's operation. The annular oil groove collects the returning oil, ensuring a smooth delivery of the oil to the high-pressure oil inlet, forming a complete cooling closed loop. The reuse of the functions of the heat dissipation oil vent and the annular oil groove allows cables to be run along the oil channel, avoiding the need for separate wiring that could compromise the seal and significantly optimizing the spatial layout.

[0036] More specifically, see Figures 1 to 6 The inner rotor 7 of the oil pump is connected to the drive shaft 2 via a key to achieve torque transmission between the drive shaft 2 and the inner rotor 7. When the drive shaft 2 drives the inner rotor 7 of the oil pump to rotate, the inner rotor 7 of the oil pump and the suction side of the outer rotor 8 of the oil pump gradually disengage, causing the volume of the suction side to increase and form a partial vacuum, which draws the low-pressure oil in the low-pressure oil chamber into the oil pump cavity. As the drive shaft 2 continues to rotate, the toothed groove filled with oil is brought to the discharge side, and the inner rotor 7 of the oil pump and the outer rotor 8 of the oil pump gradually enter the meshing state. The discharge side volume of the inner rotor 7 of the oil pump and the outer rotor 8 of the oil pump decreases, and the oil is pressurized and discharged through the high-pressure oil inlet.

[0037] In this embodiment, the inner and outer rotors of the oil pump achieve oil suction and discharge through changes in their meshing state. The suction side disengages to form a vacuum, which can actively extract oil from the low-pressure oil chamber without the need for additional oil suction power, thus improving the oil supply efficiency. The discharge side engages to reduce the volume and pressurize, allowing the oil to obtain sufficient pressure and be quickly delivered to the motor cavity, ensuring that the oil can fully flush the motor armature and remove heat. At the same time, this volumetric pressurization method can also reduce oil pulsation and make the liquid cooling cycle more stable.

[0038] It is worth mentioning that, see Figures 1 to 6 The oil circulation path includes: low-pressure oil in the external propulsion motor oil circuit → low-pressure oil inlet of the rear end cover 9 → low-pressure oil chamber of the rear end cover 9 → oil pump cavity where the gear pump structure is located; the low-pressure oil is pressurized into high-pressure oil by the gear pump structure in the oil pump cavity → high-pressure oil channel of the heat sink housing 6 → motor cavity, for liquid cooling of the motor armature 4; the liquid-cooled oil → heat dissipation oil inlet of the heat sink housing 6 → annular oil groove of the rear end cover 9 → high-pressure oil inlet of the rear end cover 9 → external propulsion motor oil circuit.

[0039] Next, the working principle of the integrated external rotor oil pump fan cooling system in an eVTOL propulsion motor involved in this embodiment of the invention will be explained. This integrated external rotor oil pump fan cooling system achieves efficient cooling of the eVTOL propulsion motor through electromagnetic drive, dual-state heat dissipation, and closed-loop oil cooling. Specifically: The system's power comes from the electromagnetic interaction between the motor armature and the magnets inside the motor's outer rotor. The drive shaft rotates under the influence of electromagnetic force, resulting in coaxial synchronous motion of the motor's outer rotor, drive shaft, and oil pump's inner rotor. In terms of air cooling, the fan blades integrated on the surface of the motor's outer rotor rotate synchronously with the rotor, directly outputting airflow to specifically cool the external propulsion motor and enhance the heat exchange efficiency of the heat dissipation terminal. In the liquid cooling system, a closed-loop circulation is adopted. Low-pressure oil from the external propulsion motor enters the low-pressure oil chamber through the low-pressure oil inlet of the rear end cover. When the rotor inside the oil pump rotates with the drive shaft, it meshes with the external rotor of the oil pump to form a gear pump effect. The volume on the suction side increases, creating a vacuum that draws in low-pressure oil, while the volume on the discharge side decreases, pressurizing the oil into high-pressure oil. The high-pressure oil enters the motor cavity through the high-pressure oil channel built into the heat sink housing, directly flushing the motor armature and absorbing heat. The oil that has completed heat exchange flows into the annular oil groove of the rear end cover through the heat dissipation oil inlet, and finally flows back to the external propulsion motor through the high-pressure oil inlet, forming a complete liquid cooling circuit of oil suction, pressurization, heat dissipation, and return.

[0040] In summary, this technical solution features a highly integrated structure. The fan blades and the outer rotor of the motor are integrated into a single design, and the oil pump is integrated into the heat sink housing. Furthermore, the outer rotor, drive shaft, and inner rotor of the oil pump are coaxially arranged, eliminating intermediate transmission mechanisms, significantly reducing installation space, improving space utilization, avoiding transmission losses, and significantly improving transmission efficiency. Moreover, it boasts outstanding heat dissipation efficiency. Through the synergy of air cooling and liquid cooling, the fan rotates synchronously with the outer rotor to enhance heat exchange with the external propulsion motor. The oil flows directly to the motor armature via a closed-loop path to flush and absorb heat. High-pressure oil channels and heat dissipation oil vents ensure directional oil delivery and smooth return, achieving highly efficient heat dissipation. In addition, it offers reliable and stable operation. The static seal at the oil separator and the dynamic seal between the outer rotor and the rear end cover prevent oil leakage and block the intrusion of external impurities. The functional reuse of the heat dissipation oil vents and annular oil grooves allows for cable routing without interfering with oil circulation, comprehensively meeting the eVTOL propulsion motor's requirements for lightweight design, efficient heat dissipation, and high reliability.

[0041] In the embodiments disclosed in this invention, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments disclosed in this invention according to the specific circumstances.

[0042] 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 principle 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 integrated external rotor oil pump fan cooling system within an eVTOL propulsion motor, characterized in that, include: The motor outer rotor (1) has a magnet installed on its inner side and a fan blade integrated on its outer surface. It is connected to the rear end cover (9) to form an installation cavity. The front end cover (3) is located inside the mounting cavity. After it is connected to the heat sink housing (6), it can press and fix the motor armature (4) to the inside of both. The heat sink housing (6) has an oil pump cavity on the side close to the rear end cover (9). The oil pump outer rotor (8) is movably disposed in the oil pump cavity. The drive shaft (2) is rotatably connected to the inner hole of the front cover (3) and the heat sink housing (6) through the bearing (10). Its first end is connected to the center of the outer rotor (1) of the motor. Its rotational power is provided by the electromagnetic action generated by the motor armature (4) and the magnet. The inner rotor (7) of the oil pump is located inside the outer rotor (8) of the oil pump and meshes with the outer rotor (8) of the oil pump to form a gear pump structure. The inner rotor (7) of the oil pump is sleeved on the second end of the drive shaft (2). The heat dissipation housing (6) is also provided with an embedded cooling channel. The output oil channel of the gear pump structure is connected to the motor cavity where the motor armature (4) is located. The motor cavity is connected to the output end of the rear cover (9), so that the oil can be output from the motor cavity to the outside.

2. The integrated external rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 1, characterized in that, An oil separator (5) is also provided at the connection between the front cover (3) and the heat sink housing (6). The oil separator (5) achieves internal sealing of the motor cavity through static sealing to prevent internal fluid from leaking when passing through the motor armature (4).

3. The integrated external rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 1, characterized in that, When the outer rotor (1) of the motor rotates, the magnet is limited by the magnet baffle (11) to prevent the magnet from being thrown out. The magnet baffle (11) is connected to the outer rotor (1) of the motor by bolts.

4. The integrated external rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 1, characterized in that, A dynamic seal is provided at the connection between the outer rotor (1) of the motor and the rear end cover (9) to prevent external media from entering the mounting cavity.

5. The integrated external rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 1, characterized in that, The front cover (3) is connected to the heat sink housing (6) by bolts, and the connection between the front cover (3) and the heat sink housing (6) is provided with a stop and a sealing groove; The heat sink housing (6) is connected to the rear end cover (9) by bolts.

6. The integrated external rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 1, characterized in that, The heat sink housing (6) is also provided with a high-pressure oil channel and a heat dissipation oil passage; One end of the high-pressure oil channel is connected to the oil outlet of the gear pump structure, and the other end is connected to the motor cavity, so that the high-pressure oil discharged from the gear pump structure can enter the motor cavity through the high-pressure oil channel; One end of the heat dissipation oil passage is connected to the motor cavity, and the other end is connected to the oil groove inside the rear end cover (9), so that the oil in the motor cavity can flow back to the oil groove of the rear end cover (9) through the heat dissipation oil passage.

7. The integrated external rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 6, characterized in that, The end face of the rear cover (9) is provided with a low-pressure oil inlet and a high-pressure oil inlet, and the interior of the rear cover (9) is provided with a low-pressure oil chamber and an annular oil groove. The low-pressure oil inlet is connected to the low-pressure oil chamber, and the low-pressure oil from the external propulsion motor oil circuit can enter the low-pressure oil chamber through the low-pressure oil inlet, and then enter the oil pump cavity where the gear pump structure is located through the low-pressure oil chamber. The annular oil groove is connected to the heat dissipation oil passage and the high-pressure oil passage interface. The oil flowing back to the oil groove of the rear cover (9) can be output from the high-pressure oil passage interface to the external propulsion motor oil circuit through the annular oil groove. The low-pressure oil inlet is equipped with a stop and a sealing groove to improve the sealing performance when connected to the external propulsion motor oil circuit.

8. The integrated external rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 7, characterized in that, The end face of the rear cover (9) is provided with a low-voltage socket mounting hole and a high-voltage socket mounting hole; The heat dissipation oil passage of the heat dissipation housing (6) and the annular oil groove of the rear end cover (9) have functional reusability. The low-voltage cable and high-voltage cable at the end of the motor armature (4) can pass through the heat dissipation oil passage to the annular oil groove, and then connect to the external low-voltage socket and high-voltage socket through the low-voltage socket mounting hole and the high-voltage socket mounting hole.

9. The integrated external rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 7, characterized in that, The inner rotor (7) of the oil pump is connected to the drive shaft (2) by a key to realize torque transmission between the drive shaft (2) and the inner rotor (7) of the oil pump; When the drive shaft (2) drives the inner rotor (7) of the oil pump to rotate, the inner rotor (7) of the oil pump and the suction side of the outer rotor (8) of the oil pump gradually disengage, causing the suction side volume to increase and forming a partial vacuum, which draws the low-pressure oil in the low-pressure oil chamber into the oil pump cavity; as the drive shaft (2) continues to rotate, the tooth groove filled with oil is brought to the discharge side, and the inner rotor (7) of the oil pump and the outer rotor (8) of the oil pump gradually enter the meshing state, and the discharge side volume of the inner rotor (7) of the oil pump and the outer rotor (8) of the oil pump decreases, and the oil is pressurized and discharged through the high-pressure oil inlet.

10. The integrated external rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 9, characterized in that, The circulation path of the oil includes: Low-pressure oil from the external propulsion motor oil circuit → low-pressure oil inlet of the rear end cover (9) → low-pressure oil chamber of the rear end cover (9) → oil pump chamber where the gear pump structure is located; Low-pressure oil is pressurized into high-pressure oil in the oil pump cavity through the gear pump structure → high-pressure oil channel of the heat sink housing (6) → motor cavity, and liquid-cools the motor armature (4); The liquid-cooled oil is passed through the heat dissipation oil passage of the heat dissipation housing (6), the annular oil groove of the rear end cover (9), the high-pressure oil passage of the rear end cover (9), and the oil circuit of the external propulsion motor.

Images