Motor assembly, thrust assembly and aircraft

Abstract

The invention discloses a motor assembly, a thrust assembly and an aircraft, and relates to the technical field of aircrafts. The motor assembly comprises an outer rotor, one axial end of the outer rotor is a mechanical coupling end, and the other axial end of the outer rotor is an open end; at least part of the inner stator extends into the outer rotor from the open end to be rotationally connected with the outer rotor, and the inner stator is provided with a central shaft hole penetrating through the inner stator in the axial direction of the inner stator; the rear cover is arranged on the side, away from the mechanical connection end, of the inner stator so as to cover the central shaft hole. The cooling assembly is arranged on the side, away from the inner stator, of the rear cover; a part of the transmission assembly is arranged in the central shaft hole and is in transmission connection with the outer rotor, and the other part of the transmission assembly penetrates through the rear cover and is in transmission connection with the cooling assembly, so that the outer rotor drives the cooling assembly through the transmission assembly. According to the motor assembly, an independent driving assembly required by the cooling assembly is omitted, so that the overall weight of the motor assembly is optimized.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft, and in particular to a motor assembly, a thrust component and an aircraft. Background Art

[0002] The thrust assembly is the power source of the electric aircraft, which mainly includes the motor, motor controller and cooling assembly. The cooling assembly is used to promptly remove the heat generated by the motor during operation, improve the heat exchange efficiency, and thus improve the heat dissipation efficiency of the motor. Among them, the cooling assembly includes structures such as a cooling pump and a radiator.

[0003] However, the cooling assembly in the related art is driven by an independent driving mechanism, and the independent driving mechanism requires an additional power supply structure to be arranged in the thrust assembly, which results in a heavier overall weight of the thrust assembly. Summary of the invention

[0004] The main purpose of the present invention is to provide a motor assembly, a thrust assembly and an aircraft, aiming to solve the technical problem in the related art that the thrust assembly is heavy due to the use of an independent electric drive assembly for the cooling assembly.

[0005] To achieve the above object, the present invention provides a motor assembly, comprising: An outer rotor, one axial end of the outer rotor is a mechanical connection end, and the other axial end of the outer rotor is an open end; An inner stator, at least a portion of which extends from an open end into the outer rotor to be rotatably connected to the outer rotor, and the inner stator has a central axial hole that penetrates the inner stator along the axial direction of the inner stator; A rear cover, which is arranged on a side of the inner stator away from the mechanical coupling end to cover the central shaft hole; A cooling assembly, the cooling assembly being arranged on a side of the rear cover away from the inner stator; and A transmission assembly, part of which is arranged in the central shaft hole and is transmission-connected to the outer rotor, and another part of which passes through the rear cover and is transmission-connected to the cooling assembly, so that the outer rotor drives the cooling assembly through the transmission assembly.

[0006] In one embodiment, the outer rotor comprises: A rotor housing, one end of the rotor housing is opened to form an open end; A rotating shaft, at least a portion of which is disposed in the rotor housing and fixedly connected to the other end of the rotor housing to form a mechanical coupling end; The rotating shaft is located outside the central shaft hole and is rotatably connected to one end of the inner stator facing the mechanical connection end through a bearing.

[0007] In one embodiment, the transmission assembly includes a transmission shaft, which is rotatably disposed in the central shaft hole around its own central axis, and the central axis of the transmission shaft is colinear with the central axis of the inner stator; One end of the transmission shaft is transmission-connected to the rotating shaft, and the other end of the transmission shaft passes through the rear cover and is transmission-connected to the cooling assembly.

[0008] In one embodiment, a first coolant flow channel is defined in the inner stator, and a coolant inlet and a coolant outlet are provided in the rear cover, and both the coolant inlet and the coolant outlet are communicated with the first coolant flow channel; The cooling package includes: A radiator assembly, the radiator assembly includes a radiator and a cooling fan, the radiator is arranged on a side of the rear cover away from the inner stator and is spaced apart from each other, and a coolant heat dissipation channel in the radiator is respectively connected to a coolant inlet and a coolant outlet to be connected to the first coolant channel to form a circulation channel; A cooling pump, the cooling pump is arranged between the radiator and the rear cover, and the cooling pump is used to drive the coolant to flow in the coolant heat dissipation channel and the first coolant channel; Wherein, the cooling pump and the cooling fan are both connected to the transmission assembly in a transmission manner.

[0009] In one embodiment, the radiator assembly further includes at least three coolant pipes, one end of the coolant pipe is fixedly connected to the radiator and communicates with the coolant heat dissipation channel, and the other end of the coolant pipe is fixedly connected to the inner stator and communicates with the coolant inlet or the coolant outlet; The coolant flowing through the radiator enters the first coolant flow channel through the coolant inlet.

[0010] In one embodiment, the cooling fan is located on a side of the radiator facing the inner stator and is spaced apart from the radiator, and the cooling fan includes an impeller shaft; the cooling pump includes a first gear shaft, and the impeller shaft and the first gear shaft are coaxial and fixedly connected to each other; Wherein, the transmission shaft is transmission-connected with the impeller shaft or the first gear shaft.

[0011] In one embodiment, the impeller shaft and the first gear shaft are integrally formed.

[0012] In one embodiment, the central axes of the impeller shaft and the first gear shaft are both colinear with the central axis of the inner stator.

[0013] In one embodiment, the cooling pump is an external gear pump, and the cooling pump further includes a first gear and a second gear, the first gear is fixedly sleeved on the first gear shaft, and the second gear is meshed with the first gear, wherein the second gear or the first gear is transmission-connected to the transmission shaft; or The cooling pump is an internal gear pump, which also includes an internal gear and a first gear, the internal gear meshing with the first gear, and the first gear is fixedly sleeved on the first gear shaft; wherein the internal gear is transmission-connected to the transmission shaft.

[0014] In one embodiment, the cooling assembly further comprises: The speed regulating gear set is arranged on the side of the rear cover away from the inner stator, and the transmission assembly is transmission-connected with the cooling assembly through the speed regulating gear set.

[0015] In one embodiment, the cooling pump includes a pump body, which is arranged on an end surface of a rear cover away from the inner stator, and a gear cavity and a pump cavity are sequentially defined in the pump body along a direction from the inner stator to the cooling assembly, and the pump cavity is connected to a circulation channel; Wherein, the speed regulating gear set is arranged in the gear cavity.

[0016] In one embodiment, the motor assembly further includes a motor controller, which is disposed in the central shaft hole, and defines an accommodation space extending along the axial direction of the inner stator; Part of the transmission assembly is arranged in the accommodating space.

[0017] In one embodiment, a second coolant flow channel is defined in the motor controller, and the second coolant flow channel is connected in series or in parallel with the first coolant flow channel and then communicated with the coolant heat dissipation flow channel.

[0018] In one embodiment, when the second coolant flow channel is connected in series with the first coolant flow channel, the first coolant flow channel includes a stator bottom plate flow channel and a winding flow channel which are connected in sequence, the stator bottom plate flow channel is connected with the second coolant flow channel, the winding flow channel includes a liquid cooling cavity defined in the stator shell of the inner stator, and the stator core and the winding of the inner stator are both arranged in the liquid cooling cavity; the second coolant flow channel is configured as an electric control board flow channel; A first rear cover flow channel and a second rear cover flow channel are defined in the rear cover, one end of the first rear cover flow channel is connected to the coolant inlet, and the other end of the first rear cover flow channel is connected to the second coolant flow channel; one end of the second rear cover flow channel is connected to the winding flow channel, and the other end of the second rear cover flow channel is connected to the coolant outlet.

[0019] In addition, the present invention also provides a thrust assembly, comprising: A motor assembly as above; and The propeller assembly is connected to the mechanical connection end of the motor assembly.

[0020] In one embodiment, the propeller assembly comprises: Propeller hub; A variable pitch motor, which is disposed in the hub and fixedly connected to the outer rotor of the motor assembly; and The variable pitch slip ring has a slip ring stator which is fixedly connected to an inner stator and electrically connected to a control module in the inner stator, and a slip ring rotor which is fixedly connected to a variable pitch motor and electrically connected.

[0021] In addition, the present invention also provides an aircraft, the aircraft comprising: Aircraft airframe; and At least one thrust assembly as described above, the thrust assembly is arranged on the aircraft body.

[0022] In one embodiment, the aircraft is an electric vertical take-off and landing aircraft.

[0023] One or more technical solutions proposed in the present invention have at least the following technical effects: In the technical solution of the motor assembly of the present invention, a transmission component is added to the existing space in the inner stator of the outer rotor motor, that is, in the central axis hole in the inner stator that penetrates the inner stator along the axial direction of the inner stator. The transmission component transmits and connects the outer rotor with a cooling component that takes away the heat generated when the motor is running, so that the cooling component is driven by the outer rotor in the motor assembly, eliminating the independent electric drive component and the required circuit wiring structure, thereby optimizing the overall weight of the motor assembly.

[0024] In addition, the outer rotor drives the cooling assembly through the transmission assembly of the mechanical transmission structure, which has higher reliability and safety than an independent electric drive assembly.

[0025] In addition, in the present invention, the control module that provides electric energy and transmits control signals to the variable pitch motor is integrated into the inner stator, which can facilitate the assembly of the thrust assembly, help reduce the assembly process, and improve assembly efficiency. In addition, the control module of the variable pitch motor is integrated into the motor controller of the electric engine, and through a unified control architecture, the system design is simplified and the control efficiency is improved, the development and maintenance costs are reduced, and the maintainability of the thrust assembly is improved. Of course, it is also convenient to configure the two redundantly, thereby improving safety. In addition, the control module of the variable pitch motor is arranged in the inner stator, which has a high degree of integration in a limited installation space, and the cooling component of the electric engine can also be used to obtain a better cooling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0027] Figure 1 A schematic diagram of the motor assembly structure provided by the present invention; Figure 2 An exploded schematic diagram of the motor assembly provided by the present invention; Figure 3 A schematic diagram of the coolant flow direction of the motor assembly provided by the present invention, wherein the transmission shaft is not shown; Figure 4 A schematic diagram of the structure of a cooling pump in a motor assembly provided by the present invention; Figure 5 A schematic diagram of the coordination between the speed regulating gear set and the external gear pump provided by the present invention; Figure 6 This is a schematic diagram of the coordination between the speed regulating gear set and the internal gear pump provided by the present invention.

[0028] Description of Figure Numbers: 10. outer rotor; 101. mechanical connection end; 102. open end; 11. rotor housing; 12. rotating shaft; 20. inner stator; 21. central axis hole; 22. first coolant flow channel; 221. stator bottom plate flow channel; 222. winding flow channel; 30. cooling assembly; 31. cooling pump; 311. pump body; 312. first gear shaft; 313. first gear; 314. second gear; 315. internal gear; 311A, gear cavity; 311B, pump cavity; 32, radiator assembly; 321, cooling fan; 322, radiator; 323, coolant pipe; 40, transmission assembly; 41, transmission shaft; 42, first mating part; 50, rear cover; 51, first rear cover flow channel; 52, second rear cover flow channel; 60, speed regulating gear set; 61, driving gear; 62, output gear; 200, variable pitch slip ring; 70, motor controller; 71, second coolant flow channel.

[0029] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0032] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0033] The motor will generate a lot of heat when in use. In the related art, the motor can be cooled by air cooling (fan forced cooling, etc.), liquid cooling (coolant such as water or oil), and combined cooling. Fan forced cooling is to add a fan to the motor and use the wind generated by the fan to force the motor to dissipate heat. Liquid cooling is to drive coolant such as water to flow through the inside of the motor through a pumping structure to absorb heat. Combined cooling combines air cooling and liquid cooling to improve the cooling effect. It can be understood that both the fan and the pumping mechanism require additional drive structures to drive their operation, and the aforementioned drive structure also requires additional circuit structures and wiring to be arranged on the motor to power the fan and the pumping mechanism.

[0034] When a rotor configuration is used on large UAVs and eVTOL (electric Vertical Take-off and Landing) and other aircraft, the rotor assembly and other thrust components are driven by an outer rotor motor. Since the power motor is a high-power heat-generating device, the heat dissipation requirement of the thrust component is higher, so the outer rotor motor in the thrust component generally adopts a combined cooling method. However, the aircraft is more sensitive to the overall weight. At this time, the combined cooling component is driven by an independent drive mechanism and an additional power supply architecture, which will cause the overall weight of the thrust component to be heavier, and then the overall weight of the aircraft to be heavier. In addition, the electric vertical take-off and landing aircraft has high requirements for space layout due to the configuration requirements. How to meet the heat dissipation requirements of high-power heat-generating devices and the reasonable arrangement of cooling components in a limited space has become a technical problem that technical personnel in this field urgently need to solve.

[0035] To this end, the present invention provides a motor assembly. By adding a transmission component in the existing space in the inner stator of the outer-rotor motor, that is, axially penetrating the central shaft hole of the inner stator along the axis of the inner stator, the transmission component drives the cooling component that takes away the heat generated during the operation of the motor in a transmission connection manner. Thus, the cooling component is driven by the outer rotor in the motor assembly, eliminating the independent electric drive component and the required circuit wiring structure, and further optimizing the overall weight of the motor assembly.

[0036] Please refer to Figure 1 and Figure 2 , this embodiment provides a motor assembly, including an outer rotor 10, an inner stator 20, a rear cover 50, a cooling component 30, and a transmission component 40.

[0037] Among them, one axial end of the outer rotor 10 is a mechanical connection end 101, and the other axial end of the outer rotor 10 is an open end 102; at least part of the inner stator 20 extends into the outer rotor 10 from the open end 102 and is rotatably connected to the outer rotor 10, and the inner stator 20 has a central shaft hole 21 that axially penetrates the inner stator 20 along the axis of the inner stator 20; the rear cover 50 is arranged on the side of the inner stator 20背离 the mechanical connection end 101 to cover the central shaft hole 21; the cooling component 30 is arranged on the side of the rear cover 50背离 the inner stator 20; part of the transmission component 40 is arranged in the central shaft hole 21 and is in transmission connection with the outer rotor 10, and the other part of the transmission component 40 passes through the rear cover 50 and is in transmission connection with the cooling component 30, so that the outer rotor 10 drives the cooling component 30 through the transmission component 40.

[0038] Specifically, the motor in this embodiment is an outer-rotor motor. The rotor of the outer-rotor motor forms the outer rotor 10 on the outside, and the stator forms the inner stator 20 on the inside. Among them, the inner stator 20 includes a stator housing, a stator core, and windings. The stator core is installed in the stator housing, and the windings are embedded in the stator slots of the stator core. The stator housing is formed into a U-shaped housing. At this time, the shaft hole of the stator housing forms the central shaft hole 21, that is, the central axis of the central shaft hole 21 coincides with the central axis of the inner stator 20. It can be understood that the axial direction of the inner stator 20 is the axial direction of the motor assembly.

[0039] The outer rotor 10 is generally constructed as a tubular member with an opening on one side, and its opening side forms an open end 102, so that the inner stator 20 can be installed into the outer rotor 10 from the open end 102. A plurality of magnetic poles are fixed on the inner circumferential surface of the outer rotor 10. It can be understood that the outer rotor 10 forms the front cover of the motor and covers one end of the inner stator 20. Correspondingly, the other side of the outer rotor 10 is a mechanical connection end 101, and the mechanical connection end 101 is used to transmit force, motion, and torque to the outside. When the motor assembly in this embodiment is used as the drive motor of the thrust component of an aircraft, the mechanical connection end 101 is connected to the hub of the propeller to transmit power, so that the propeller generates the lift and thrust required for flight.

[0040] The other end of the inner stator 20 is covered by the rear cover 50. The rear cover 50 is used to seal the inner stator 20 to prevent foreign matter from entering the motor, so that a storage space for laying out corresponding circuit boards or other circuit structures is formed inside the inner stator 20. In addition, the rear cover 50 is also provided with a coolant inlet and outlet, so that the coolant can pass through the rear cover 50 to enter the inner stator 20 on the other side of the rear cover after cooling from the cooling assembly 30 on one side of the rear cover 50, or the coolant can pass through the rear cover 50 to flow into the cooling assembly 30 after heat exchange from the winding, which will be explained in detail below.

[0041] Since the central axis hole 21 inside the inner stator 20 is connected to the axial ends of the inner stator 20, and the outer rotor 10 and the cooling assembly 30 are respectively located at the axial ends of the inner stator 20, in this embodiment, part of the transmission assembly 40 is arranged in the central axis hole 21 and extends to the mechanical connection end to be transmission-connected with the mechanical connection end 101, and the other part of the transmission assembly 40 passes through the rear cover 50 and is transmission-connected with the cooling assembly 30, thereby transmitting the rotational motion of the outer rotor 10 to the cooling assembly 30 to drive the air cooling assembly and / or liquid cooling assembly of the cooling assembly 30 to start operation.

[0042] It is not difficult to see that in this embodiment, a transmission assembly 40 is added to the existing space in the inner stator 20 of the outer rotor motor, that is, the central axis hole 21 in the inner stator 20 that penetrates the inner stator 20 along the axial direction of the inner stator 20. The transmission assembly 40 transmits and connects the outer rotor 10 with the cooling assembly 30 that takes away the heat generated when the motor is running, so that the cooling assembly 30 is driven by the outer rotor 10 in the motor assembly, and the independent electric drive assembly and the required circuit wiring structure of the cooling assembly 30 in the related art are eliminated, thereby optimizing the overall weight of the motor assembly. In addition, the outer rotor 10 drives the cooling assembly 30 through the transmission assembly 40 of the mechanical transmission structure, which has higher reliability and safety than the independent electric drive assembly.

[0043] In addition, most of the transmission assembly 40 in this embodiment is arranged in the central axis hole 21 in the inner stator 20, and the existing structure and layout of the motor and cooling assembly 30 in the motor assembly are not changed, which is conducive to promotion and use in existing products.

[0044] In addition, this embodiment eliminates the independent electric drive component required for the cooling component 30, and can also avoid the heat dissipation problem and heat dissipation risk of the independent electric drive component.

[0045] It should be noted that the motor can be a dual-bearing motor or a single-bearing motor. In one embodiment, when the motor is a dual-bearing motor, a hollow tubular stator bracket is provided in the central axis hole 21 of the inner stator 20, and the stator bracket is fixedly connected to the inner peripheral wall of the stator core of the inner stator 20 through a plurality of arms protruding from its outer peripheral wall, and one end of the stator bracket protrudes from the end of the inner stator 20 away from the mechanical connection end 101 and is installed with a bearing, and the end of the inner stator 20 facing the mechanical connection end 101 is also installed with a bearing. At this time, the rotating shaft 12 of the outer rotor 10 is installed in the stator bracket and its two ends are respectively matched with two bearings. In this embodiment, the transmission assembly 40 can be arranged in the stator bracket.

[0046] Of course, for aircraft, in order to reduce the weight and size of the whole machine, the motor preferably adopts a single-bearing motor. The following also takes the motor as a single-bearing motor as an example for explanation. At this time, the outer rotor 10 includes: a rotor housing 11 and a rotating shaft 12, one end of the rotor housing 11 is open to form an open end 102; at least part of the rotating shaft 12 is arranged in the rotor housing 11 and is fixedly connected to the other end of the rotor housing 11 to form a mechanical connection end 101; wherein the rotating shaft 12 is located outside the central shaft hole 21, and is rotatably connected to the end of the inner stator 20 facing the mechanical connection end 101 through a bearing.

[0047] Specifically, see Figure 2 The rotor housing 11 of the outer rotor 10 is generally constructed as a cylindrical member with one side open, and the open side is formed as an open end 102. The outer rotor 10 also includes a rotating shaft 12, and the central axis of the rotating shaft 12 is colinear with the central axis of the inner stator 20. It is worth mentioning that at least part of the rotating shaft 12 is disposed in the rotor housing 11, and the rotating shaft 12 may be partially disposed in the rotor housing 11, such as a part of the rotating shaft 12 is located in the rotor housing 11, and the other part protrudes from the rotor housing 11 in a direction away from the inner stator 20 and is located outside the rotor housing 11.

[0048] Alternatively, see Figure 1 and Figure 2, or the rotating shaft 12 can be completely arranged in the rotor housing 11, in which case a coupling hole is provided at the geometric center of the other end of the rotor housing 11 opposite to the open end 102, the rotating shaft is arranged in the rotor housing 11 and extends along the axial direction of the inner stator 20, and one axial end of the rotating shaft 12 is connected to the rotor housing 11 at the coupling hole by a bolt group. The other axial end of the rotating shaft 12 is rotationally connected to the end of the inner stator 20 toward the mechanical coupling end 101 through a bearing, so that the outer rotor motor of the motor assembly provided in this embodiment is a single-bearing motor. In addition, the rotating shaft 12 is provided with a rotating shaft hole that penetrates the rotating shaft 12 along the axial direction of the rotating shaft 12, and the hole wall of the rotating shaft hole and / or the end surface of the rotating shaft 12 on one side away from the inner stator 20 are provided with a coupling structure to form a mechanical coupling end 101. As in one example, the mounting structure of the propeller system extends into the rotating shaft hole through the coupling hole and cooperates with the coupling structure.

[0049] In this embodiment, when the propeller system transmits the overturning moment through the connection structure on the rotating shaft 12, a part of the overturning moment is transmitted to the rotor housing 11 through the rotating shaft 12, and the other part of the overturning moment is transmitted to the inner stator 20 through the rotating shaft 12 and the bearing. Since the connection structure is located in the rotating shaft hole, the deformation caused by the overturning moment can be resisted by the structural reinforcement design (such as increasing the wall thickness) at the connection between the rotating shaft 12, the inner stator 20 and the bearing, and the structural reinforcement design (such as increasing the wall thickness) at the connection between the rotor housing 11 and the rotating shaft 12. In addition, the rest of the rotor housing 11 can adopt a thin-wall design, so that when it is subjected to the overturning moment, a certain deformation is generated on the transmission path, which can reduce the deformation of the rotor housing 11. Of course, due to the single bearing design, in order to ensure the structural strength, the radii of the rotating shaft 12, the outer rotor 10 and the inner stator 20 all need to be increased. However, relatively speaking, increasing the radius also increases the radius of the propeller installation circle, achieving the effect of improving the mass distribution of the propeller system and improving the distribution of the overturning moment.

[0050] It is easy to understand that the single-bearing motor in which the rotating shaft 12 is located outside the central shaft hole 21 significantly reduces the total weight of the motor assembly. In addition, the rotating shaft 12 is located outside the central shaft hole 21, and the central shaft hole 21 can also have sufficient space to arrange the electronic components on the motor. In this way, in this embodiment, the transmission assembly 40 is installed in the central shaft hole 21 of the single-bearing motor, which can make full use of the existing space in the single-bearing motor, making the space utilization more reasonable. Of course, installing the transmission assembly 40 in the central shaft hole 21 can also make the overall weight distribution of the motor assembly more uniform and reasonable compared to leaving the central shaft hole 21 empty.

[0051] In addition, since the rotating shaft 12 is located outside the central shaft hole 21, sufficient space is left in the central shaft hole 21. Therefore, in one embodiment, the transmission assembly 40 includes a transmission shaft 41, which is rotatably disposed in the central shaft hole 21 around its own central axis, and the central axis of the transmission shaft 41 is colinear with the central axis of the inner stator 20; wherein one end of the transmission shaft 41 is transmission-connected to the rotating shaft 12, and the other end of the transmission shaft 41 passes through the rear cover 50 and is transmission-connected to the cooling assembly 30.

[0052] Specifically, the transmission assembly 40 is used to transmit the rotation of the rotating shaft 12 to the cooling assembly 30, so it includes a first matching portion 42 that is transmission-connected to the rotating shaft 12, a second matching portion that matches the cooling assembly 30, and a transmission portion that connects the first matching portion 42 and the second matching portion. In this embodiment, the transmission portion is configured as a transmission shaft 41 that is coaxially arranged with the inner stator 20, and the transmission shaft 41 rotates around its own central axis, that is, around the central axis of the inner stator 20.

[0053] It is not difficult to see that in this embodiment, arranging the transmission shaft 41 at the central axis of the inner stator 20 can reduce the interference of the transmission shaft 41 with the operation of the inner stator 20 and the outer rotor 10, and can also make the weight distribution of the motor assembly symmetrical.

[0054] It is worth mentioning that, since the transmission shaft 41 is arranged at the central axis of the inner stator 20, the transmission shaft 41 can be directly fixedly connected to the rotating shaft 12. For example, when the rotating shaft 12 is constructed as a cylindrical structure, one end of the transmission shaft 41 is fixed to the rotating shaft 12 by welding, shaft hole matching or flange, that is, the aforementioned first matching portion 42 and the transmission portion are integrated into a transmission shaft 41.

[0055] Alternatively, when the rotating shaft 12 has a rotating shaft hole, one end of the transmission shaft 41 extends into the rotating shaft hole of the rotating shaft 12 and is fixedly connected to the inner peripheral wall of the rotating shaft 12 through the first matching portion 42. As an option, the first matching portion 42 can be configured as a disc. As another option, see Figure 1 The first matching portion 42 is configured as a plurality of arms evenly and spaced apart along the circumferential direction of the transmission shaft 41, and the arms extend to be fixedly connected to the inner peripheral wall of the rotating shaft 12. In one example, the plurality of arms are configured as a "cross" structure.

[0056] Of course, in another embodiment, in order to leave enough space for wiring, the transmission part of the transmission assembly 40 can be arranged eccentrically in the inner stator 20, that is, when the transmission part is arranged in the central axis hole through a support structure such as a bracket, its central axis is parallel to the central axis of the inner stator 20 and spaced apart from each other. In this case, the first matching portion 42 can be constructed as a gear set or a transmission belt assembly, etc., so as to prevent the outer rotor 10 from driving the transmission part as a whole to rotate around the central axis of the inner stator 20 while transmitting the rotation of the outer rotor 10 to the transmission part.

[0057] As before, the cooling assembly 30 may include an air cooling assembly (such as a cooling fan 321), a liquid cooling assembly (such as a heat exchanger and a pumping assembly that pumps the coolant into the motor so that the coolant flows through the motor), or a combination of an air cooling assembly and a liquid cooling assembly. For example, when the motor assembly is configured as a drive motor for a propeller of a small drone, the cooling assembly 30 may only include an air cooling assembly. Alternatively, when the motor assembly is configured as a drive motor for a propeller on an eVTOL, the cooling assembly 30 may be a liquid cooling assembly or a combination of an air cooling assembly and a liquid cooling assembly.

[0058] In one embodiment, a first coolant flow channel 22 is defined in the inner stator 20 , and the rear cover 50 is provided with a coolant inlet and a coolant outlet communicated with the first coolant flow channel 22 .

[0059] The cooling component 30 includes: a radiator assembly 32 and a cooling pump 31. The radiator assembly 32 includes a radiator 322 and a cooling fan 321. The radiator 322 is arranged on the side of the rear cover 50 away from the inner stator 20 and are spaced apart from each other, and the coolant heat dissipation channel in the radiator 322 is respectively connected to the coolant inlet and the coolant outlet to connect with the first coolant channel 22 to form a circulation channel; the cooling pump 31 is arranged between the radiator 322 and the inner stator 20, and the cooling pump 31 is used to drive the coolant to flow in the first coolant channel 22 and the coolant heat dissipation channel; wherein the cooling pump 31 and the cooling fan 321 are both connected to the transmission component 40 in a transmission manner.

[0060] Specifically, the coolant inlet and the coolant outlet of the first coolant flow channel 22 are both opened in the rear cover 50. In one example, the rear cover 50 is provided with a plurality of through holes, wherein the coolant inlet is near the center of the rear cover 50, and the coolant outlet is near the edge of the rear cover 50.

[0061] It is worth mentioning that the number of the first coolant flow channel 22 can be one, or multiple first coolant flow channels 22 can be connected in parallel to reduce the length of a single first coolant flow channel 22, thereby removing heat from the inner stator 20 as quickly as possible. Multiple first coolant flow channels 22 can achieve uniform flow distribution of the coolant by designing corresponding pipe diameters.

[0062] See also Figure 1 , Figure 2 and Figure 3 , the radiator assembly 32 in the cooling component 30 is located on the side of the rear cover 50 away from the inner stator 20 and is spaced apart from each other, so as to leave enough space for installing the cooling pump 31 and for air flow. The connection relationship between the coolant heat dissipation channel, the first coolant channel 22 and the cooling pump 31 can be specifically that after the cooling pump 31 is connected to the coolant heat dissipation channel of the radiator 322, the cooling pump 31 is connected to the coolant inlet, and the coolant heat dissipation channel in the radiator 322 is connected to the coolant outlet. Alternatively, after the cooling pump 31 is connected to the coolant heat dissipation channel of the radiator 322, the cooling pump 31 is connected to the coolant outlet, and the coolant heat dissipation channel in the radiator 322 is connected to the coolant inlet. Alternatively, in order to simplify the connection relationship and facilitate the installation of the cooling pump 31, the coolant heat dissipation channel is connected to the first coolant channel 22, and the cooling pump 31 is arranged on the first coolant channel 22, thereby driving the coolant in the first coolant channel 22 to flow, and then promoting the coolant to circulate in the coolant heat dissipation channel and the first coolant channel 22.

[0063] The coolant exchanges heat with the outside air in the coolant heat dissipation channel. The cooling fan 321 and the radiator 322 can be arranged in sequence in the axial direction of the inner stator 20, such as the radiator 322 is close to the rear cover 50 and the cooling fan 321 is far away from the rear cover 50. Alternatively, in order to promote sufficient heat exchange between the outside air and the radiator 322, such as Figures 1 to 3 As shown, the heat dissipation fan 321 is close to the rear cover 50 and the heat sink 322 is arranged away from the rear cover 50 .

[0064] In one example, the cooling fan 321 is close to the rear cover 50 and the radiator 322 is arranged away from the rear cover 50, and the cooling pump 31 is arranged on the first coolant flow channel 22, and the coolant heat dissipation flow channel in the radiator 322 is connected to the coolant outlet. At this time, the cooling pump 31 drives the low-temperature coolant to flow in the first coolant flow channel 22 in the inner stator 20, and absorbs the heat generated by the motor, especially the winding, and becomes a high-temperature liquid to extract the heat in the inner stator 20. After leaving the inner stator 20, the high-temperature liquid enters the radiator 322, and becomes a low-temperature coolant after heat exchange with the outside air in the radiator 322, thereby completing the heat dissipation cycle. The cooling fan 321 works on the side of the radiator 322 close to the rear cover 50, so that the outside air can flow through the surface of the radiator 322 to exchange heat. Of course, the cooling fan 321 can also cause air to flow through the inside or outside of the motor to take away heat.

[0065] In addition, the heat sink 322 can be connected to the inner stator 20 through an additional connection structure. Figure 1The radiator assembly 32 also includes at least three coolant pipes 323, one end of the coolant pipe 323 is fixedly connected to the radiator 322 and communicated with the coolant heat dissipation channel, and the other end of the coolant pipe 323 is fixedly connected to the rear cover 50 and communicated with the coolant inlet or the coolant outlet; the coolant flowing through the radiator 322 enters the first coolant channel 22 through the coolant inlet.

[0066] Specifically, all the coolant pipes 323 can be return pipes for the coolant in the inner stator 20 to flow back to the radiator 322. At this time, the coolant in the radiator 322 flows into the inner stator 20 through the cooling pump 31. It can be understood that a plurality of coolant pipes 323 can be evenly spaced along the circumferential direction of the inner stator 20 to better stress the motor assembly as a whole.

[0067] Alternatively, when the cooling pump 31 is arranged on the first coolant flow channel 22, part of the coolant pipe 323 is a liquid outlet pipe, and the other part of the coolant pipe 323 is a liquid return pipe, and the liquid outlet pipe and the liquid return pipe are fixedly connected to the radiator 322 and the inner stator 20 respectively. At this time, the radiator 322 includes a liquid outlet connected to the liquid outlet pipe in a one-to-one correspondence, and a liquid return port connected to the liquid return pipe in a one-to-one correspondence. Of course, the radiator 322 also includes a pump outlet connected to the cooling pump 31. In addition, the number of liquid outlet pipes and liquid return pipes can be consistent and arranged in pairs. At this time, the liquid outlet pipe and the liquid return pipe can be evenly spaced and alternately arranged along the circumferential direction of the inner stator 20, so that the coolant can flow into the radiator 322 from two opposite areas on the radiator 322, and flow out of the radiator 322 from two opposite areas on the radiator 322, which is conducive to the uniform heat dissipation of the coolant in the radiator 322.

[0068] In this embodiment, the coolant pipe 323 is not only a liquid pipeline, but also a structural component supporting and connecting the radiator 322 and the inner stator 20. It is an integrated design, thereby improving the integration of components and reducing the number of components.

[0069] In addition, when the cooling fan 321 is located on one side end surface of the radiator 322 facing the inner stator 20 and is spaced apart from the radiator 322, the number of the cooling fan 321 can be one or more. Preferably, when there is one cooling fan 321, the cooling fan 321 includes an impeller shaft; the cooling pump 31 includes a first gear shaft 312; the impeller shaft and the first gear shaft 312 are coaxial and fixedly connected to each other, wherein the transmission shaft 41 is transmission-connected to the impeller shaft or the first gear shaft 312.

[0070] Generally speaking, the cooling fan 321 includes an impeller and an impeller shaft. The impeller rotates at high speed driven by the impeller shaft, thereby generating negative pressure to promote gas flow. There are many types of pumps, among which gear pumps and vane pumps both include a first gear shaft 312 that rotates around its own central axis. In this embodiment, please refer to Figure 1 , the impeller shaft rotating around its own axis and the first gear shaft 312 rotating around its own axis are coaxial and fixedly connected to each other, so that when the transmission shaft 41 is in transmission connection with the impeller shaft or the first gear shaft 312, the impeller shaft and the first gear shaft 312 can be driven to rotate together, so as to simultaneously drive the impeller of the cooling fan 321 and the first gear 313 of the cooling pump 31 to operate. It can be seen that this embodiment saves the transmission structure between the cooling fan 321 and the cooling pump 31, thereby simplifying the mechanical structure inside the motor assembly and reducing the overall weight.

[0071] It can be understood that, as an option of this embodiment, the impeller shaft and the first gear shaft 312 can be connected via a coupling.

[0072] Alternatively, as an alternative to this example, see Figure 1 , the impeller shaft and the first gear shaft 312 are an integrally formed part. At this time, the impeller shaft and the first gear shaft 312 are the same shaft, a part of which is located in the cooling pump 31, and the other part passes through the pump body 311 of the cooling pump 31 and extends toward the radiator 322, and the impeller of the cooling fan 321 is installed on the other part. It is easy to understand that compared with the connection method such as the coupling, the impeller shaft and the first gear shaft 312 are an integrally formed part, which can further reduce the number of parts of the motor assembly, making the size of the motor assembly in its axial direction smaller, and further reducing the overall weight.

[0073] In addition, after the impeller shaft and the first gear shaft 312 are coaxially arranged, both can be staggered with the central axis of the inner stator 20, that is, eccentrically arranged, or both can be collinear with the central axis of the inner stator 20, and this embodiment does not limit this. It can be understood that the eccentric arrangement is conducive to leaving space in the axial direction of the motor to arrange other components, while the collinear arrangement is conducive to making the radial shape of the motor assembly smaller and more regular, so as to facilitate arrangement on platforms such as aircraft that have higher requirements for aerodynamic shape.

[0074] As before, the cooling pump 31 can be an impeller pump or a gear pump, wherein the main working parts of the gear pump are the meshing gears. When the gears rotate, the change in the volume between the teeth forms a suction and discharge effect. The liquid is transported or pressurized by relying on the change in the working volume formed between the pump body 311 and the meshing gears, while the impeller pump relies on the impeller to drive the liquid to rotate at high speed to transfer mechanical energy to the transported liquid. Since the gear pump has a simple structure, reliable operation, and low price, it is suitable for occasions requiring high pressure and large flow. Therefore, when the motor assembly is suitable for aircraft, the cooling pump 31 can use a gear pump.

[0075] As an option, the cooling pump 31 is an external gear pump, and the cooling pump 31 also includes a first gear 313 and a second gear 314, the first gear 313 is fixedly sleeved on the first gear shaft 312, and the second gear 314 is meshed with the first gear 313, wherein the second gear 314 or the first gear 313 is transmission-connected to the transmission shaft 41.

[0076] Specifically, the pump body 311 of the cooling pump 31 is fixed to the end surface of the rear cover 50 which is away from the inner stator 20. Figure 1 , Figure 4 and Figure 5 , a second gear 314 and a first gear 313 meshing with each other are installed in the pump body 311. Since the cooling pump 31 is closer to the transmission shaft 41 than the cooling fan 321, the second gear 314 of the cooling pump 31 can be connected to the transmission shaft 41, so that the transmission shaft 41 drives the second gear 314 to rotate, and the second gear 314 drives the first gear 313 to rotate, and then drives the impeller of the cooling fan 321 to rotate. Alternatively, the first gear 313 of the cooling pump 31 can be connected to the transmission shaft 41, so that the transmission shaft 41 drives the first gear 313 to rotate, the first gear 313 drives the second gear 314 to rotate, and the first gear 313 drives the impeller of the cooling fan 321 to rotate. That is, in this embodiment, the first gear or the second gear 314 can be used as the driving gear of the cooling pump 31, and this embodiment is not limited to this.

[0077] Alternatively, as another option, the cooling pump 31 is an internal gear pump, and the cooling pump 31 also includes an internal gear 315 and a first gear 313, the internal gear 315 is meshed with the first gear 313, and the first gear 313 is fixedly sleeved on the first gear shaft 312; wherein the first gear 313 is transmission connected to the transmission shaft 41.

[0078] Generally speaking, the main parts of an internal gear pump are a pair of meshing internal gears 315 and external gears, and a crescent-shaped spacer. Figure 6 In this embodiment, the internal gear 315 rotates around its own axis under the drive of the transmission shaft 41. The external gear, that is, the first gear 313, is sleeved on the first gear shaft 312 and is eccentric relative to the central axis of the internal gear 315. It rotates under the drive of the internal gear 315. The function of the crescent-shaped spacer is to separate the suction chamber and the discharge chamber. During operation, when the active internal gear 315 rotates, a partial vacuum is formed where the gear teeth are disengaged, and the coolant enters the pump body 311 under the action of atmospheric pressure and fills the spaces between the teeth. Where the gear teeth are engaged, the coolant between the teeth is squeezed and discharged from the pump body 311. Of course, the first gear 313 then drives the impeller of the cooling fan 321 to rotate.

[0079] Of the two aforementioned options, the internal gear pump and the external gear pump have a compact structure, small size, and good suction performance, which are more conducive to the motor assembly being suitable for platforms such as aircraft.

[0080] It is understandable that when the motor speed is consistent with the speed requirement of the cooling fan 321, the transmission shaft can be directly connected to the gear shaft or impeller shaft in the cooling assembly 30, that is, no reducer or other structures are required. Alternatively, when the motor speed is different from the gear speed of the cooling pump 31 in the cooling assembly 30, in one embodiment, the cooling assembly 30 further includes: a speed regulating gear set 60, the speed regulating gear set 60 is arranged on the side of the rear cover 50 away from the inner stator 20, and the transmission assembly 40 is connected to the cooling assembly 30 through the speed regulating gear set 60.

[0081] Specifically, the speed regulating gear set 60 includes a plurality of gears that cooperate with each other. It is understandable that the speed regulating gear set 60 can be designed with different transmission gear ratios to increase or decrease the speed, so as to match the motor speed with the speeds of the cooling pump 31 and the cooling fan 321 .

[0082] It can be understood that the speed regulating gear set 60 can be independently designed with a speed regulating housing, and the speed regulating housing can be fixed to the rear cover 50 by structures such as bolts or rivets, or can also be integrally formed with the rear cover 50. Then the speed regulating gear set 60 is installed in the speed regulating housing, wherein the transmission shaft 41 penetrates the rear cover 50 and one side wall of the speed regulating housing and extends into the speed regulating housing, and is coaxial and fixedly connected with the gear shaft of the driving gear 61 of the speed regulating gear set 60, and the gear shaft of the output gear 62 of the speed regulating gear set 60 penetrates the other side wall of the speed regulating housing and is coaxial and fixedly connected with the first gear shaft 312 of the cooling pump 31, or is coaxial and fixedly connected with the gear shaft of the second gear 314, or can also be coaxial and fixedly connected with the gear shaft of the internal gear 315.

[0083] Alternatively, in one embodiment, see Figure 4 The cooling pump 31 includes a pump body 311, which is fixedly arranged on the end surface of the rear cover 50 facing away from the inner stator 20; a gear cavity 311A ​​and a pump cavity 311B are sequentially defined in the pump body 311 along the direction from the inner stator 20 to the cooling assembly 30, and the pump cavity 311B is connected to the circulation channel; wherein the speed regulating gear set 60 is arranged in the gear cavity 311A.

[0084] Specifically, the pump body 311 of the cooling pump 31 is fixed to the end face of the rear cover 50 away from the inner stator 20 by bolts or rivets, or can be integrally formed with the rear cover 50. Two cavities are defined in the pump body 311 along the axial direction of the inner stator 20, of which the gear cavity 311A ​​is close to the rear cover 50, and the pump cavity 311B is far away from the rear cover 50. The pump cavity 311B is connected to the circulation channel to drive the coolant to circulate in the circulation channel. The two cavities are connected to facilitate the installation of the gear shaft of the speed regulating gear set 60 and / or the gear of the cooling pump 31. Of course, in order to prevent the lubricating oil in the gear cavity 311A ​​from contaminating the coolant in the pump cavity 311B, a sealing ring or other sealing member can be used to seal the gear shaft across the two cavities.

[0085] In one example, see Figure 2 , Figure 4 and Figure 5 , the speed regulating gear set 60 includes two gears, and the cooling pump 31 is an external gear pump. At this time, the gear chamber 311A ​​includes two first sub-cavities, the central axes of the two first sub-cavities are parallel and the distance between them is less than the sum of the radius of the two, and the central axis of one of the first sub-cavities is collinear with the central axis of the inner stator 20, and the other first sub-cavity is eccentrically arranged. The pump chamber 311B includes two second sub-cavities, the central axis of one of the second sub-cavities is collinear with the central axis of one of the aforementioned first sub-cavities, and the central axis of the other second sub-cavity is collinear with the central axis of the other first sub-cavity. The transmission shaft 41 passes through the rear cover 50 and the pump body 311, and extends into one of the aforementioned first sub-cavities. At this time, the driving gear 61 of the speed regulating gear set 60 is sleeved on the transmission shaft 41. The output gear 62 of the speed regulating gear is installed in the aforementioned other first sub-cavity, and its gear shaft extends into the aforementioned other second sub-cavity, so that the second gear 314 is sleeved on the gear shaft. The first gear 313 is installed in one of the aforementioned second sub-cavities, and the first gear shaft 312 is coaxial with the transmission shaft 41 but separated from each other. In addition, after the first gear shaft 312 passes through the pump body 311, it continues to extend in the axial direction of the inner stator 20 in a direction away from the inner stator 20 to provide for the installation of the impeller of the cooling fan 321. This example ensures that the transmission shaft 41 and the cooling fan 321 are both arranged on the central axis of the inner stator 20, achieving a better symmetrical design of the thrust assembly.

[0086] In addition, when the motor is installed on a platform such as an aircraft and used as an electric engine, it is the power source of the electric aircraft. It is understandable that in an aircraft, during specific operation, a motor controller is required to convert the input power of the onboard power supply into the power required for the motor drive, and to adjust the motor operating parameters. Therefore, in one embodiment, the motor assembly also includes a motor controller 70, which is disposed in the central shaft hole, and a housing space extending along the axial direction of the inner stator 20 is defined in the motor controller 70; wherein a portion of the transmission assembly 40 is disposed in the housing space.

[0087] Specifically, please refer to Figures 1 to 3 , the rear cover 50 is configured as a U-shaped housing, and the open end of the rear cover 50 is fixedly connected to the inner stator 20 through fasteners such as bolts. The U-shaped housing and the stator housing of the inner stator 20 together enclose a space. The motor controller 70 is installed in this space. Alternatively, the motor controller 70 extends into the central shaft hole from the side of the inner stator 20 away from the mechanical connection end. At this time, the housing of the motor controller 70 is configured as the rear cover 50 to cover the central shaft hole. In this way, the overall weight of the electric engine can be reduced, and it is beneficial to the installation between the motor controller 70 and the inner stator 20.

[0088] The motor controller 70 includes a plurality of electronic components. To facilitate the transmission shaft 41 to pass through, and since the installation of each electronic component inside the motor controller 70 can be spaced apart from each other to leave sufficient space, a receiving space extending along the axial direction of the inner stator 20 can be defined inside the motor controller 70 for placing the transmission shaft 41.

[0089] It is not difficult to see that compared with the cooling component of the electric engine in the related art, it is difficult for the traditional independent electric drive component to meet the safety requirements of the aircraft. The electric engine provided in this embodiment drives the radiator fan and the pump in the cooling component 30 through mechanical transmission structures such as the transmission shaft, with higher reliability, so that the safety of the electric engine is improved.

[0090] In addition, since a large amount of heat is also generated by the power devices inside the motor controller during operation, in one embodiment, a second coolant flow channel 71 is defined inside the motor controller 70. The second coolant flow channel 71 is connected in series or in parallel with the first coolant flow channel 22 and then communicated with the coolant heat dissipation flow channel, so that the coolant driven by the coolant pump 31 flows inside to take away the heat generated inside the motor controller.

[0091] It can be understood that when the second coolant flow channel 71 is connected in series with the first coolant flow channel 22, the second coolant flow channel 71, the first coolant flow channel 22, and the coolant heat dissipation flow channel together form a circulation flow channel, and the coolant pump 31 drives the coolant to flow in the circulation flow channel. When the second coolant flow channel 71 is connected in parallel with the first coolant flow channel 22, the second coolant flow channel 71 and the first coolant flow channel 22 are respectively communicated with the coolant heat dissipation flow channel, thereby forming two circulation flow channels.

[0092] In one embodiment, when the second coolant flow channel 71 is connected in series with the first coolant flow channel 22, the first coolant flow channel 22 includes a stator bottom plate flow channel 221 and a winding flow channel 222 which are connected in sequence, the winding flow channel 222 includes a liquid cooling cavity defined in the stator shell of the inner stator 20, the stator core and the winding of the inner stator 20 are both arranged in the liquid cooling cavity, and the second coolant flow channel 71 is constructed as an electric control board flow channel; a first rear cover flow channel 51 is defined in the rear cover 50, one end of the first rear cover flow channel 51 is connected to the coolant inlet, and the other end of the first rear cover flow channel 51 is connected to the second coolant flow channel 71; the rear cover 50 also defines a second rear cover flow channel 52, one end of the second rear cover flow channel 52 is connected to the winding flow channel 222, and the other end of the second rear cover flow channel 52 is connected to the coolant outlet.

[0093] Specifically, the part of the stator housing of the inner stator 20 near the mechanical connection end is the stator bottom plate. The stator bottom plate defines a stator bottom plate flow channel 221. The part of the stator housing for installing the winding defines a winding flow channel. The rear cover 50 is provided with a plurality of through holes, of which the one near the center of the rear cover 50 is the coolant inlet, and the one near the edge of the rear cover 50 is the coolant outlet. A first rear cover flow channel 51 is provided in the bottom plate of the rear cover 50 (the end away from the inner stator), one end of the first rear cover flow channel 51 is connected to the coolant inlet, and the other end thereof is connected to the second coolant flow channel 71. It can be understood that the cooling pump 31 can be arranged on the first rear cover flow channel 51, so that the cooling pump 31 is integrated into the rear cover 50 and the connection relationship between the cooling pump 31 and the flow channel in the motor assembly is simpler.

[0094] At least one cooling plate is arranged in the space enclosed by the rear cover 50 and the inner stator 20, and various power devices in the motor controller 70 are mounted on the cooling plate, such as the power module of the drive motor and the power module of the drive cooling assembly 30, the DC bus capacitor, and the control module for controlling the pitch-changing assembly of the propeller, etc. An electric control board flow channel, i.e., the second coolant flow channel 71, is defined in the cooling plate.

[0095] In addition, a plurality of second rear cover flow channels 52 are also provided in the peripheral wall of the rear cover 50 , and one end of the second rear cover flow channel 52 is connected to the winding flow channel 222 in the inner stator, and the other end is connected to the coolant outlet.

[0096] In addition, it should be noted that the winding flow channel 222 is arranged around all windings to take away the heat generated by each winding, or each winding flow channel 222 passes through each corresponding winding along the axial direction of the inner stator to facilitate the rapid removal of heat. Alternatively, the winding flow channel 222 includes a liquid cooling cavity defined in the stator shell of the inner stator 20, and the stator core and windings of the inner stator 20 are both arranged in the liquid cooling cavity. In this way, the coolant can immerse the heat-generating components of the inner stator 20 to improve the cooling effect.

[0097] In addition, in order to achieve the above-mentioned purpose, the present invention also provides a thrust assembly, including: a motor assembly and a propeller assembly, and the mechanical connection end 101 of the propeller assembly is connected to the motor assembly.

[0098] The specific structure of the motor assembly refers to the above embodiment. Since the thrust assembly adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here. In addition, due to the reduced weight, the present application can also improve the torque density of the thrust assembly.

[0099] The propeller assembly is connected to the mechanical connection end 101 of the motor assembly, so as to rotate driven by the outer rotor 10 .

[0100] In one embodiment, the propeller assembly includes a hub, a pitch motor and a pitch slip ring 200, wherein the pitch motor is disposed in the hub and fixedly connected to the outer rotor 10. The slip ring stator of the pitch slip ring 200 is fixedly connected to the inner stator 20 and electrically connected to the control module in the inner stator 20, and the slip ring rotor of the pitch slip ring 200 is fixedly connected and electrically connected to the pitch motor, thereby supplying power to the pitch motor when the thrust assembly is running.

[0101] See also Figure 1 In one embodiment, the slip ring stator is sleeved on one end of the transmission shaft 41 close to the rotating shaft 12, and the part of the variable pitch motor can extend into the rotating shaft hole of the rotating shaft 12 to be connected with the slip ring rotor, so that the variable pitch slip ring is placed in the existing space of the inner stator 20 to make full use of the internal space of the motor, which is conducive to reducing the overall axial size of the thrust assembly.

[0102] In this embodiment, the control module that provides electric energy and transmits control signals to the variable pitch motor is integrated into the motor controller 70, which can facilitate the assembly of the thrust assembly, help reduce the assembly process, and improve assembly efficiency. In addition, the control module of the variable pitch motor is integrated into the motor controller of the electric engine, and through a unified control architecture, the system design is simplified and the control efficiency is improved, the development and maintenance costs are reduced, and the maintainability of the thrust assembly is improved. Of course, it is also convenient to configure the two redundantly, thereby improving safety. In addition, the control module of the variable pitch motor is arranged in the inner stator, which has a high degree of integration in a limited installation space, and the cooling component of the electric engine can also be used to obtain a better cooling effect.

[0103] Alternatively, in some embodiments, the variable pitch motor includes a first winding and a second winding, and the control module is connected to the first winding and the second winding respectively through a connecting cable. In this way, the variable pitch motor forms a dual winding structure, thereby forming a dual redundancy configuration to improve safety. At this time, since the dual winding design increases the volume of the variable pitch motor and the space in the hub is limited, in order to arrange the control module corresponding to the variable pitch motor, the control module can be arranged in the inner stator 20.

[0104] In addition, the present invention also provides an aircraft, which includes an aircraft body and at least one thrust assembly, wherein the thrust assembly is arranged on the aircraft body.

[0105] The specific structure of the thrust assembly refers to the above-mentioned embodiments. Since the aircraft adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0106] The aircraft may be a drone or an electric vertical take-off and landing aircraft eVTOL.

[0107] The above are only exemplary embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A motor assembly, characterized in that: include: An outer rotor, wherein one axial end of the outer rotor is a mechanical connection end, and the other axial end of the outer rotor is an open end; An inner stator, at least a portion of which extends from the open end into the outer rotor to be rotatably connected to the outer rotor, and the inner stator has a central axial hole that penetrates the inner stator along the axial direction of the inner stator; A rear cover, the rear cover is arranged on a side of the inner stator away from the mechanical coupling end to cover the central shaft hole; A cooling assembly, the cooling assembly being arranged on a side of the rear cover away from the inner stator; as well as A transmission assembly, part of which is disposed in the central shaft hole and is transmission-connected to the outer rotor, and another part of which passes through the rear cover and is transmission-connected to the cooling assembly, so that the outer rotor drives the cooling assembly through the transmission assembly.

2. The motor assembly according to claim 1, characterized in that: The outer rotor comprises: A rotor housing, one end of which is open to form the open end; a rotating shaft, at least a portion of which is disposed in the rotor housing and fixedly connected to the other end of the rotor housing to form the mechanical coupling end; Wherein, the rotating shaft is located outside the central axis hole, and is rotationally connected to one end of the inner stator facing the mechanical coupling end through a bearing.

3. The motor assembly according to claim 2, characterized in that: The transmission assembly comprises a transmission shaft, which is rotatably arranged in the central shaft hole around its own central axis, and the central axis of the transmission shaft is colinear with the central axis of the inner stator; Among them, one end of the transmission shaft is transmission-connected to the rotating shaft, and the other end of the transmission shaft passes through the rear cover and is transmission-connected to the cooling assembly.

4. The motor assembly according to claim 3, characterized in that: A first coolant flow channel is defined in the inner stator, and a coolant inlet and a coolant outlet are provided in the rear cover, and both the coolant inlet and the coolant outlet are communicated with the first coolant flow channel; The cooling assembly comprises: A radiator assembly, the radiator assembly comprising a radiator and a cooling fan, the radiator being arranged on a side of the rear cover away from the inner stator and spaced apart from each other, and a cooling liquid heat dissipation channel in the radiator being respectively connected to the cooling liquid inlet and the cooling liquid outlet to be connected to the first cooling liquid channel to form a circulation channel; A cooling pump, the cooling pump is arranged between the radiator and the rear cover, and the cooling pump is used to drive the coolant to flow in the coolant heat dissipation channel and the first coolant channel; Wherein, the cooling pump and the heat dissipation fan are both transmission-connected to the transmission assembly.

5. The motor assembly according to claim 4, characterized in that: The radiator assembly further includes at least three coolant pipes, one end of each coolant pipe is fixedly connected to the radiator and communicates with the coolant heat dissipation channel, and the other end of each coolant pipe is fixedly connected to the rear cover and communicates with the coolant inlet or the coolant outlet; The coolant flowing through the radiator enters the first coolant flow channel through the coolant inlet.

6. The motor assembly according to claim 4, characterized in that: The cooling fan is located on a side of the radiator facing the inner stator and is spaced apart from the radiator, and the cooling fan comprises an impeller shaft; The cooling pump comprises a first gear shaft, and the impeller shaft is coaxial with the first gear shaft and fixedly connected to each other; Wherein, the transmission shaft is transmission-connected to the impeller shaft or the first gear shaft.

7. The motor assembly according to claim 6, characterized in that: The impeller shaft and the first gear shaft are integrally formed; and / or The central axes of the impeller shaft and the first gear shaft are both colinear with the central axis of the inner stator.

8. The motor assembly according to claim 7, characterized in that: The cooling pump is an external gear pump, and the cooling pump further comprises a first gear and a second gear, the first gear is fixedly sleeved on the first gear shaft, and the second gear is meshed with the first gear, wherein the second gear or the first gear is drivingly connected to the transmission shaft; or The cooling pump is an internal gear pump, and the cooling pump also includes an internal gear and a first gear, the internal gear is meshed with the first gear, and the first gear is fixedly sleeved on the first gear shaft; wherein the internal gear is transmission-connected to the transmission shaft.

9. The motor assembly according to claim 4, characterized in that: The cooling assembly also includes: A speed regulating gear set is arranged on a side of the rear cover away from the inner stator, and the transmission assembly is transmission-connected to the cooling assembly via the speed regulating gear set.

10. The motor assembly according to claim 9, characterized in that: The cooling pump comprises a pump body, which is arranged on the end surface of the rear cover away from the inner stator, and the pump body defines a gear cavity and a pump cavity in sequence along the direction from the inner stator to the cooling assembly, and the pump cavity is connected to the circulation channel; Wherein, the speed regulating gear set is arranged in the gear cavity.

11. The motor assembly according to claim 4, characterized in that: The motor assembly further includes a motor controller, which is disposed in the central shaft hole, and defines an accommodation space extending along the axial direction of the inner stator; Wherein, part of the transmission assembly is arranged in the accommodating space.

12. The motor assembly according to claim 11, characterized in that: A second coolant flow channel is defined in the motor controller, and the second coolant flow channel is connected in series or in parallel with the first coolant flow channel and then communicated with the coolant heat dissipation flow channel.

13. The motor assembly according to claim 12, characterized in that: When the second coolant flow channel is connected in series with the first coolant flow channel, the first coolant flow channel includes a stator bottom plate flow channel and a winding flow channel which are connected in sequence, the stator bottom plate flow channel is connected with the second coolant flow channel, the winding flow channel includes a liquid cooling cavity defined in a stator shell of an inner stator, and the stator core and winding of the inner stator are both arranged in the liquid cooling cavity; the second coolant flow channel is configured as an electric control board flow channel; A first rear cover flow channel and a second rear cover flow channel are defined in the rear cover, one end of the first rear cover flow channel is connected to the coolant inlet, and the other end of the first rear cover flow channel is connected to the second coolant flow channel; one end of the second rear cover flow channel is connected to the winding flow channel, and the other end of the second rear cover flow channel is connected to the coolant outlet.

14. A thrust assembly, characterized in that: include: The motor assembly according to any one of claims 1 to 13; as well as A propeller assembly is connected to the mechanical connection end of the motor assembly.

15. The thrust assembly of claim 14, wherein: The propeller assembly comprises: Propeller hub; A variable pitch motor, which is disposed in the hub and fixedly connected to the outer rotor of the motor assembly; and The variable pitch slip ring has a slip ring stator which is fixedly connected to an inner stator and electrically connected to a control module in the inner stator, and a slip ring rotor which is fixedly connected to a variable pitch motor and electrically connected.

16. An aircraft, characterized in that: The aircraft comprises: Aircraft airframe; and At least one thrust assembly according to claim 14 or 15, said thrust assembly being arranged on said aircraft body.

17. The aircraft according to claim 16, characterized in that The aircraft is an electric vertical take-off and landing aircraft.

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