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

Abstract

The invention relates to an integrated inner 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, independent transmission parts are omitted through three-body series connection coaxial layout, the system size is greatly reduced, the weight is reduced, meanwhile, power transmission loss is reduced, the operation efficiency is improved, inertia matching of the oil pump unit and the cooling fan is achieved, a rotor of the driving motor unit serves as an intermediate mass block to adjust dynamic response, and the problem of power unbalance is solved. Besides, the cavity of the oil pump unit and the heat dissipation shell are integrally designed, so that the structure is simplified, the oil flow retention time is prolonged through an embedded spiral cooling flow channel, the drive motor unit is cooled through branched oil flow, and local overheating is avoided; the main oil flow and the external propulsion motor form closed-loop circulation, and the main oil flow and air cooling of the cooling fan form collaborative heat dissipation of the external propulsion motor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas-liquid self-circulation cooling of electric propulsion motors, and in particular to an integrated inner rotor oil pump fan cooling system in an eVTOL propulsion motor. BACKGROUND

[0002] In recent years, with the rapid development of low-altitude economy, electric vertical take-off and landing aircraft (eVTOL) has attracted widespread attention at home and abroad, and has shown deep market potential and application value. As the core component of the eVTOL drive system, the performance, volume, weight and other characteristics of the propulsion motor need to meet the stringent flight condition requirements. However, due to the design requirements of high power density and compact layout of the eVTOL propulsion motor, the motor is prone to serious heat accumulation during operation. If the heat cannot be dissipated in time, it will directly affect the reliability and service life of the propulsion motor.

[0003] In the existing liquid cooling configuration of the propulsion motor circulation cooling technology, the oil pump, the cooling fan and their respective driving motor modules are generally designed in a distributed manner. This design not only leads to a large overall cooling system volume, but also makes the connection pipeline between the oil pump and the fan complex and redundant, which is difficult to adapt to the core requirements of lightweight and space-intensive internal components of the eVTOL propulsion motor. At the same time, the existing integrated oil pump fan system is deeply coupled with the main propulsion motor and the cooling system, and lacks independent operation capability, resulting in poor system interchangeability, which is not conducive to later maintenance and adaptation to different types of eVTOL propulsion motors.

[0004] Therefore, in order to effectively improve the heat dissipation efficiency of the propulsion motor and optimize the overall performance of the cooling system, it is urgent to design an oil pump fan driving motor integrated system with high integration, high efficiency and high interchangeability. SUMMARY

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

[0006] To achieve the above purpose, the technical solution adopted by the present application is: An integrated inner rotor oil pump fan cooling system in an eVTOL propulsion motor, comprising: A driving motor unit is arranged inside a cooling shell, which includes a main shaft, a rotor sleeved on the main shaft, and a stator located outside the rotor. The main shaft serves as the driving shaft of the oil pump unit and the cooling fan. The inner rotor of the oil pump unit, the rotor and the cooling fan form a three-body serial coaxial layout. The interior of the heat dissipation shell is provided with an embedded cooling flow channel, the cavity of the oil pump unit is formed integrally with the heat dissipation shell, and the oil pump unit forms two oil flows during the transmission of the flow, one branch oil flow enters the embedded cooling flow channel of the heat dissipation shell to liquid cool the stator and rotor of the driving motor unit, and the other main oil flow is used to connect the liquid cooling oil circuit of the external propulsion motor.

[0007] In some embodiments, one end of the main shaft of the driving motor unit is connected with the inner rotor of the oil pump unit through a spline, the oil pump unit further comprises an outer rotor and a low-pressure oil port and a high-pressure oil port arranged respectively, the inner rotor is engaged with the outer rotor, and the inner rotor can suck oil liquid from the low-pressure oil port through periodic increase of the chamber volume, and then output the oil liquid from the high-pressure oil port to the liquid cooling oil circuit of the external propulsion motor through pressure increase caused by volume reduction. The other end of the main shaft is connected with the cooling fan through a flat key, and the cooling fan generates directional airflow when rotating with the main shaft, and outputs high-pressure air volume in a direction away from the heat dissipation shell to act on the external propulsion motor.

[0008] In some embodiments, the low-pressure oil port of the oil pump unit is communicated with the oil return port of the external propulsion motor, and the oil returned after liquid cooling of the external propulsion motor is returned to the oil pump unit through the low-pressure oil port to provide continuous oil liquid supply for the oil pump unit; and a leakage prevention sealing ring is arranged at the interface of the low-pressure oil port to prevent oil liquid from leaking into the gap between the stator and the rotor of the driving motor unit.

[0009] In some embodiments, the oil pump unit and the driving motor unit are jointly packaged inside the heat dissipation shell, and the embedded cooling flow channel of the heat dissipation shell is a preset cooling oil circuit, which is only used for internal liquid cooling of the driving motor unit, and directly contacts the stator winding end and the rotor core through oil flow to take away the heat generated during operation of the driving motor unit.

[0010] In some embodiments, the embedded cooling flow channel of the heat dissipation shell is spirally distributed along the winding end of the stator and the outer periphery of the rotor core, the spiral structure prolongs the residence time of the oil flow in the oil circuit, and improves the heat conduction efficiency; and the oil inlet end of the spiral oil circuit is communicated with the oil outlet of the branch oil flow of the oil pump unit, and the oil outlet end of the spiral oil circuit is communicated with the low-pressure oil port of the oil pump unit.

[0011] In some embodiments, the high-pressure oil port of the oil pump unit is provided with a flow regulating valve in the liquid cooling oil circuit of the external propulsion motor, the flow regulating valve receives a temperature sensor signal of the external propulsion motor, increases the main flow when the temperature of the external propulsion motor is too high, and reduces the main flow when the temperature is too low.

[0012] In some embodiments, the main oil flow path of the oil pump unit comprises: external propulsion motor oil return port→low pressure oil port of the oil pump unit→the inner rotor and the outer rotor meshing to increase pressure→high pressure oil port output of the oil pump unit→external propulsion motor oil inlet port→after taking away heat→external propulsion motor oil return port→low pressure oil port of the oil pump unit again, forming a closed loop.

[0013] In some embodiments, the shunt oil flow path of the oil pump unit comprises: the inner rotor and the outer rotor meshing to increase pressure→shunt oil outlet port of the oil pump unit→embedded cooling flow channel of the heat dissipation shell→taking away heat of the stator and the rotor→from the oil outlet end of the embedded cooling flow channel→low pressure oil port of the oil pump unit→joining the main oil flow, forming a closed loop.

[0014] The technical solution provided by the present application has at least the following beneficial effects: The three-body coaxial layout of the present application eliminates the need for independent transmission components, greatly reduces the system volume and weight, reduces power transmission loss, improves operating efficiency, and realizes inertial matching of the oil pump unit and the cooling fan. The rotor of the drive motor unit serves as an intermediate mass block to adjust the dynamic response, solving the problem of power imbalance. In addition, the integrated design of the oil pump unit cavity and the heat dissipation shell simplifies the structure, the embedded spiral cooling flow channel prolongs the oil flow residence time, the shunt oil flow cools the drive motor unit, avoiding local overheating; the main oil flow and the external propulsion motor form a closed loop, and the air cooling of the cooling fan forms a cooperative cooling of the external propulsion motor. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, together with the embodiments of the present application, to explain the present application, and do not constitute a limitation of the present application.

[0016] Figure 1 A layout schematic diagram of an integrated inner rotor oil pump fan cooling system in an eVTOL propulsion motor is shown.

[0017] Figure 2 An exploded schematic diagram of an integrated inner rotor oil pump fan cooling system in an eVTOL propulsion motor is shown.

[0018] Figure 3 A principle schematic diagram of an integrated inner rotor oil pump fan cooling system in an eVTOL propulsion motor is shown.

[0019] In the figure: 1; oil pump unit; 1.1, inner rotor; 1.2, outer rotor; 2. drive motor unit; 2.1 stator; 2.2 rotor; 2.3 main shaft; 3. cooling fan; 4. heat dissipation shell. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0021] In the drawings, the same components are denoted by the same reference numerals. It should be noted that the words "front", "back", "left", "right", "up" and "down" used in the following description refer to the directions in the drawings of the present application, and the words "bottom" and "top", "inner" and "outer" refer to the directions towards or away from a particular component. In addition, the terms "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features with "first" and "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "a plurality of" is two or more.

[0022] The present application will be further described below with reference to the drawings and embodiments.

[0023] Figure 1 A layout schematic diagram of an integrated inner rotor oil pump fan cooling system in an eVTOL propulsion motor is shown, Figure 2 An exploded schematic diagram of an integrated inner rotor oil pump fan cooling system in an eVTOL propulsion motor is shown, which includes a drive motor unit 2 arranged inside a heat dissipation shell 4, which includes a main shaft 2.3, a rotor 2.2 sleeved on the main shaft 2.3, and a stator 2.1 located outside the rotor 2.2. The main shaft 2.3 simultaneously serves as a driving shaft of an oil pump unit 1 and a cooling fan 3. The inner rotor 1.1 of the oil pump unit 1, the rotor 2.2 and the cooling fan 3 form a three-body series coaxial layout. The interior of the heat dissipation shell 4 is provided with an embedded cooling flow channel. The cavity of the oil pump unit 1 is integrated with the heat dissipation shell 4. The oil pump unit 1 forms two oil flows during transmission of flow. One branch oil flow enters the embedded cooling flow channel of the heat dissipation shell 4 to perform liquid cooling on the stator 2.1 and the rotor 2.2 of the drive motor unit 2. The other main oil flow is used to connect the liquid cooling oil circuit of the external propulsion motor.

[0024] In the embodiment of the present application, the three-body tandem coaxial layout drives the inner rotor of the oil pump, the rotor of the motor unit and the cooling fan synchronously by the main shaft, eliminates independent transmission components, greatly compresses the system volume and reduces the weight to adapt to the space intensification and light weight demand of eVTOL propulsion motor, and reduces power transmission loss and improves operation efficiency; the embedded cooling flow channel of the heat dissipation shell and the cavity of the oil pump unit are designed integrally, which simplifies the overall structure, cooperates with the double oil flow division, and makes the branch oil flow targeted for cooling and preventing overheating of the driving motor unit, and the main oil flow stably supplies energy for the external propulsion motor.

[0025] In detail, referring to Figure 1 and Figure 2 , one end of the main shaft 2.3 of the driving motor unit 2 is connected with the inner rotor 1.1 of the oil pump unit 1 through a spline, the oil pump unit 1 further includes an outer rotor 1.2 and a low-pressure oil port and a high-pressure oil port respectively arranged, the inner rotor 1.1 is engaged with the outer rotor 1.2, and the inner rotor 1.1 can suck oil liquid from the low-pressure oil port through periodic increase of the chamber volume, and then output the oil liquid from the high-pressure oil port to the liquid cooling oil circuit of the external propulsion motor after increasing the pressure of the oil liquid through volume reduction; the other end of the main shaft 2.3 is connected with the cooling fan 3 through a key, and the cooling fan 3 generates directional airflow when rotating with the main shaft 2.3, and outputs high-pressure air volume in a direction away from the heat dissipation shell 4 and acts on the external propulsion motor.

[0026] In the embodiment of the present application, the spline connection of the main shaft and the inner rotor of the oil pump unit can transmit greater torque and ensure transmission stability, provide reliable power for the engagement operation of the inner and outer rotors, and ensure that the oil suction and pressure increase are stably completed through the chamber volume change, so as to deliver sufficient pressure oil liquid to the liquid cooling oil circuit of the external propulsion motor; the separate arrangement of the low-pressure oil port and the high-pressure oil port clearly defines the oil liquid input and output path, and ensures the order of oil liquid circulation. The key connection of the main shaft and the cooling fan is convenient for assembly and can realize synchronous rotation, so that the high-pressure air volume output by the cooling fan is directed to the external propulsion motor, and forms a cooperative heat dissipation with the liquid cooling.

[0027] In more detail, referring to Figure 1 and Figure 2 , the low-pressure oil port of the oil pump unit 1 is communicated with the oil return port of the external propulsion motor, and the oil returned after the liquid cooling of the external propulsion motor is returned to the oil pump unit 1 through the low-pressure oil port to provide continuous oil supply for the oil pump unit 1; and a leakage-proof sealing ring is arranged at the interface of the low-pressure oil port to avoid the leakage of oil liquid into the gap between the stator 2.1 and the rotor 2.2 of the driving motor unit 2.

[0028] In the embodiment of the present application, the low-pressure oil port of the oil pump unit is communicated with the oil return port of the external propulsion motor, in order to build an oil liquid closed loop circulation, recycle the oil liquid after the liquid cooling of the external motor to realize reuse, continuously supply oil source for the oil pump unit, and ensure the uninterrupted operation of the liquid cooling circuit.

[0029] Specifically, referring to Figure 1 and Figure 2 , the oil pump unit 1 and the drive motor unit 2 are jointly packaged inside the heat dissipation shell 4, and the embedded cooling flow channel of the heat dissipation shell 4 is the preset cooling oil circuit, which is only used for internal liquid cooling of the drive motor unit 2. The heat generated by the operation of the drive motor unit 2 is taken away by directly contacting the winding end of the stator 2.1 and the core of the rotor 2.2 through oil flow. The embedded cooling flow channel of the heat dissipation shell 4 is distributed in a spiral shape along the winding end of the stator 2.1 and the outer periphery of the core of the rotor 2.2. The spiral structure prolongs the residence time of the oil flow in the oil circuit, and improves the heat conduction efficiency. The oil inlet end of the spiral oil circuit is in communication with the oil outlet of the shunt oil flow of the oil pump unit 1, and the oil outlet end of the spiral oil circuit is in communication with the low-pressure oil port of the oil pump unit 1.

[0030] In the embodiments of the present application, the oil pump unit and the drive motor unit are jointly packaged in the heat dissipation shell, which greatly compresses the overall space to adapt to the compact demand of the eVTOL propulsion motor. The embedded cooling flow channel is used for internal liquid cooling of the drive motor unit, and the heat generated by the operation of the drive motor unit is taken away, so as to avoid local overheating affecting the performance. The design of the spiral flow channel prolongs the residence time of the oil, so that the heat absorption is more sufficient, and the heat conduction efficiency is significantly improved.

[0031] In some embodiments, the high-pressure oil port of the oil pump unit 1 is provided with a flow regulating valve in the liquid cooling oil circuit of the external propulsion motor. The flow regulating valve receives the temperature sensor signal of the external propulsion motor. When the temperature of the external propulsion motor is too high, the main flow is increased, and when the temperature is too low, the main flow is reduced.

[0032] More specifically, referring to Figure 1 and Figure 2 , the main oil flow path of the oil pump unit 1 includes: the oil return port of the external propulsion motor→the low-pressure oil port of the oil pump unit 1→the meshing and pressure increasing of the inner rotor 1.1 and the outer rotor 1.2→the high-pressure oil port output of the oil pump unit 1→the oil inlet port of the external propulsion motor→after taking away the heat→the oil return port of the external propulsion motor→entering the low-pressure oil port of the oil pump unit 1 again, forming a closed loop. The shunt oil flow path of the oil pump unit 1 includes: the meshing and pressure increasing of the inner rotor 1.1 and the outer rotor 1.2→the shunt oil outlet of the oil pump unit 1→the embedded cooling flow channel of the heat dissipation shell 4→taking away the heat of the stator 2.1 and the rotor 2.2→from the oil outlet end of the embedded cooling flow channel→the low-pressure oil port of the oil pump unit 1→combined with the main oil flow, forming a closed loop.

[0033] Next, in combination with Figure 3 , the working principle of an integrated inner rotor oil pump fan cooling system in an eVTOL propulsion motor according to an embodiment of the present application will be described. Figure 3 The fan unit in is a cooling fan.

[0034] In power transmission, one end of the main shaft of the driving motor unit is connected with the inner rotor of the oil pump unit through a spline, and the other end is connected with the cooling fan through a flat key. The inner rotor of the oil pump unit, the rotor of the driving motor and the cooling fan are arranged coaxially, and when the main shaft rotates, the three are synchronously driven to operate, without the need for independent transmission components. The oil flow circulation is divided into two paths. The main oil flow serves the external propulsion motor liquid cooling. The oil return port of the external propulsion motor enters the low-pressure oil port of the oil pump unit. The inner and outer rotors of the oil pump unit mesh to increase the oil pressure through volume change. The oil is output from the high-pressure oil port of the oil pump unit. After the oil takes away the heat of the external propulsion motor, it is returned to the oil pump unit from the oil return port, forming a closed loop. The branch oil flow is used for the liquid cooling of the internal driving motor unit. When the oil pump unit increases the pressure, the branch oil flow is introduced to the embedded cooling flow channel of the heat dissipation shell. The embedded cooling flow channel is attached to the stator winding end and the rotor core, prolonging the oil flow residence time and improving the heat conduction efficiency. After cooling, the oil is returned to the low-pressure oil port of the oil pump unit from the oil outlet of the embedded cooling flow channel, and is combined with the main oil flow. Further, when the cooling fan rotates with the main shaft, it outputs high-pressure air volume away from the heat dissipation shell, providing air cooling for the external propulsion motor, and forming synergistic heat dissipation with the liquid cooling of the main oil flow.

[0035] In summary, the technical solution of the present application realizes coaxial arrangement of the three units, eliminates independent transmission components, greatly reduces the system volume and weight, reduces power transmission loss, improves operation efficiency, realizes inertia matching of the oil pump unit and the cooling fan, adjusts the dynamic response by the rotor of the driving motor unit as an intermediate mass block, and solves the power imbalance problem. Furthermore, the cavity of the oil pump unit and the heat dissipation shell are designed integrally to simplify the structure, the embedded spiral cooling flow channel prolongs the oil flow residence time, the branch oil flow cools the driving motor unit to avoid local overheating, the main oil flow and the external propulsion motor form a closed loop circulation, and the air cooling of the cooling fan forms synergistic heat dissipation for the external propulsion motor.

[0036] In the embodiments disclosed in the present application, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense. For example, "connection" can be fixed connection, detachable connection or integral connection. "Connection" can be direct connection or indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the embodiments disclosed in the present application can be understood according to the specific circumstances.

[0037] The above description is only the preferred embodiments of the present application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the protection scope of the present application.

Claims

1. An integrated internal rotor oil pump fan cooling system within an eVTOL propulsion motor, characterized in that, include: The drive motor unit (2) is located inside the heat dissipation housing (4). It includes a main shaft (2.3), a rotor (2.2) sleeved on the main shaft (2.3), and a stator (2.1) located outside the rotor (2.2). The main shaft (2.3) also serves as the drive shaft for the oil pump unit (1) and the cooling fan (3). The inner rotor (1.1) of the oil pump unit (1), the rotor (2.2) and the cooling fan (3) form a three-body series coaxial layout. The heat dissipation housing (4) has an embedded cooling channel inside. The cavity of the oil pump unit (1) is integrally formed with the heat dissipation housing (4). During the transmission flow, the oil pump unit (1) forms two oil flows. One branch oil flow enters the embedded cooling channel of the heat dissipation housing (4) to liquid cool the stator (2.1) and rotor (2.2) of the drive motor unit (2). The other main oil flow is used to connect to the liquid cooling oil circuit of the external propulsion motor.

2. The integrated internal rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 1, characterized in that, One end of the main shaft (2.3) of the drive motor unit (2) is connected to the inner rotor (1.1) of the oil pump unit (1) via a spline. The oil pump unit (1) also includes an outer rotor (1.2) and low-pressure oil port and high-pressure oil port respectively. The inner rotor (1.1) meshes with the outer rotor (1.2) and can periodically increase the volume of the chamber to draw in oil from the low-pressure oil port, and then increase the pressure of the oil by reducing the volume and output it from the high-pressure oil port to the liquid cooling oil circuit of the external propulsion motor. The other end of the main shaft (2.3) is connected to the cooling fan (3) via a flat key. When the cooling fan (3) rotates with the main shaft (2.3), it generates directional airflow and outputs high-pressure airflow in a direction away from the heat dissipation housing (4), which acts on the external propulsion motor.

3. The integrated internal rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 2, characterized in that, The low-pressure oil port of the oil pump unit (1) is connected to the return oil port of the external propulsion motor. The return oil after the external propulsion motor completes liquid cooling flows back to the oil pump unit (1) through the low-pressure oil port, providing continuous oil supply to the oil pump unit (1). Furthermore, the interface of the low-pressure oil port is provided with a leak-proof sealing ring to prevent oil leakage from seeping into the gap between the stator (2.1) and rotor (2.2) of the drive motor unit (2).

4. The integrated internal rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 3, characterized in that, The oil pump unit (1) and the drive motor unit (2) are encapsulated together inside the heat dissipation housing (4). The embedded cooling channel of the heat dissipation housing (4) is the preset cooling oil circuit. This oil circuit is only used for the internal liquid cooling of the drive motor unit (2). The oil flow directly contacts the stator (2.1) winding end and the rotor (2.2) core, carrying away the heat generated by the operation of the drive motor unit (2).

5. The integrated internal rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 4, characterized in that, The embedded cooling channels of the heat dissipation housing (4) are spirally distributed along the winding end of the stator (2.1) and the outer periphery of the iron core of the rotor (2.2). The spiral structure prolongs the residence time of the oil flow in the oil circuit and improves the heat conduction efficiency. The oil inlet of the spiral oil circuit is connected to the oil outlet of the branch oil flow of the oil pump unit (1), and the oil outlet of the spiral oil circuit is connected to the low-pressure oil port of the oil pump unit (1).

6. The integrated internal rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 5, characterized in that, The high-pressure oil port of the oil pump unit (1) is equipped with a flow regulating valve in the liquid cooling oil circuit of the external propulsion motor. The flow regulating valve receives the temperature sensor signal of the external propulsion motor. When the temperature of the external propulsion motor is too high, the main flow rate is increased, and when the temperature is too low, the main flow rate is decreased.

7. The integrated internal rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 6, characterized in that, The main oil flow path of the oil pump unit (1) includes: The oil return port of the external propulsion motor → the low-pressure oil port of the oil pump unit (1) → the inner rotor (1.1) meshes with the outer rotor (1.2) to increase pressure → the high-pressure oil port of the oil pump unit (1) outputs → the oil inlet of the external propulsion motor → after taking away heat → the oil return port of the external propulsion motor → re-enters the low-pressure oil port of the oil pump unit (1), forming a closed loop.

8. The integrated internal rotor oil pump fan cooling system in the eVTOL propulsion motor according to claim 6, characterized in that, The branched oil flow paths of the oil pump unit (1) include: The inner rotor (1.1) meshes with the outer rotor (1.2) to increase pressure → oil is drawn from the branch oil outlet of the oil pump unit (1) → into the embedded cooling channel of the heat dissipation housing (4) → heat from the stator (2.1) and the rotor (2.2) is carried away → from the oil outlet of the embedded cooling channel → the low-pressure oil port of the oil pump unit (1) → merges with the main oil flow to form a closed loop.

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