Motor assembly, thrust assembly and aircraft

Abstract

The utility model 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 cooling assembly is arranged on the side, away from the mechanical connection end, of the inner stator; a part of the transmission assembly is arranged in the central shaft hole, and the transmission assembly is in transmission connection with the outer rotor and the cooling assembly, so that the outer rotor drives the cooling assembly through the transmission assembly. According to the utility model, 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] This utility model relates to the field of aircraft technology, and in particular to an electric motor assembly, a thrust assembly, and an aircraft. Background Technology

[0002] The thrust assembly is the power source for electric aircraft, and it mainly includes the motor, motor controller, and cooling assembly. The cooling assembly is used to remove the heat generated by the motor during operation, improving heat exchange efficiency and thus improving the motor's heat dissipation efficiency. The cooling assembly includes structures such as cooling pumps and radiators.

[0003] However, the cooling components in the related technologies are driven by a separate drive mechanism, and the separate drive mechanism requires an additional power supply architecture to be arranged in the thrust assembly, which results in a heavier overall weight of the thrust assembly. Utility Model Content

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

[0005] To achieve the above objectives, this utility model proposes a motor assembly, comprising:

[0006] The outer rotor has one axial end that is a mechanical connection end and the other axial end that is an open end.

[0007] The inner stator, at least a portion of which extends from the open end into the outer rotor and is rotatably connected to the outer rotor, and the inner stator has a central shaft hole that extends through the inner stator along its axial direction;

[0008] Cooling assembly, the cooling assembly is disposed on the side of the inner stator opposite to the mechanical connection end; and

[0009] The transmission assembly is partially disposed within the central shaft hole and is connected to both the outer rotor and the cooling assembly, thereby enabling the outer rotor to drive the cooling assembly via the transmission assembly.

[0010] In one embodiment, the outer rotor includes:

[0011] Rotor housing, with one end of the rotor housing open to form an open end;

[0012] A rotating shaft, at least a portion of which is disposed within a rotor housing and fixedly connected to the other end of the rotor housing to form a mechanical connection end;

[0013] The rotating shaft is located outside the central shaft hole and is rotatably connected to the end of the inner stator facing the mechanical connection end via a bearing.

[0014] In one embodiment, the transmission assembly includes a transmission shaft rotatably disposed within a central shaft hole about its own central axis, and the central axis of the transmission shaft is collinear with the central axis of the inner stator; wherein one end of the transmission shaft is drivenly connected to a rotating shaft, and the other end of the transmission shaft is drivenly connected to a cooling assembly; or

[0015] The transmission assembly includes an eccentric shaft, which is rotatably disposed in a central shaft hole about its own central axis, and the central axis of the eccentric shaft is parallel to and spaced apart from the central axis of the central shaft hole; wherein, one end of the eccentric shaft is drivenly connected to the cooling assembly, and the other end of the eccentric shaft is drivenly connected to the outer rotor, so that the outer rotor drives the cooling assembly through the eccentric shaft.

[0016] In one embodiment, a first coolant flow channel is defined within the inner stator, and the inner stator has a coolant inlet and a coolant outlet communicating with the first coolant flow channel;

[0017] The cooling components include:

[0018] The radiator assembly includes a radiator and a cooling fan. The radiators are located on the side of the inner stator away from the mechanical connection end and are spaced apart from each other. The coolant cooling channels in the radiator are respectively connected to the coolant inlet and the coolant outlet to form a circulation channel with the first coolant channel.

[0019] A cooling pump is located between the radiator and the inner stator, and is used to drive the coolant to flow in the coolant heat dissipation channel and the first coolant channel.

[0020] Both the cooling pump and the cooling fan are connected to the transmission components.

[0021] In one embodiment, the radiator assembly further includes at least three coolant pipes, one end of which is fixedly connected to the radiator and communicates with the coolant flow channel, and the other end of which is fixedly connected to the inner stator and communicates with the coolant inlet or coolant outlet; wherein the coolant flowing through the radiator enters the first coolant flow channel through the coolant inlet.

[0022] In one embodiment, the cooling fan is located on the side of the radiator facing the inner stator and 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 is coaxial with the first gear shaft and fixedly connected to it.

[0023] The drive shaft is connected to either the impeller shaft or the first gear shaft.

[0024] In one embodiment, 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 collinear with the central axis of the inner stator.

[0025] 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 a first gear shaft, and the second gear meshes with the first gear. Either the second gear or the first gear is connected to a drive shaft or an eccentric shaft for transmission; or...

[0026] The cooling pump is an internal gear pump, which also includes an internal gear and a first gear. The internal gear meshes with the first gear, and the first gear is fixedly sleeved on the first gear shaft. The internal gear is connected to a drive shaft or an eccentric shaft.

[0027] In one embodiment, the cooling assembly further includes:

[0028] The speed regulating gear set is located on the side of the inner stator away from the mechanical connection end, and the transmission component is connected to the cooling component through the speed regulating gear set.

[0029] In one embodiment, the cooling pump includes a pump body disposed on the side end face of the inner stator away from the mechanical connection end. The pump body defines a gear cavity and a pump cavity sequentially along the direction from the inner stator to the cooling assembly. The pump cavity is connected to a circulation channel.

[0030] The speed regulating gear set is located inside the gear cavity.

[0031] In one embodiment, the motor assembly further includes a motor controller, which is fixedly disposed in the central shaft hole and defines an accommodating space extending axially along the inner stator.

[0032] The transmission component is located within the accommodating space.

[0033] In one embodiment, a second coolant flow channel is defined within the motor controller. The second coolant flow channel is connected in series or in parallel with the first coolant flow channel and then communicates with the coolant heat dissipation flow channel.

[0034] 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 first rear cover flow channel, a stator base plate flow channel, a winding flow channel, and a second rear cover flow channel. 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 stator base plate flow channel is connected to the second coolant flow channel, and the other end of the stator base plate flow channel is connected to one end of the winding flow channel. One end of the second rear cover flow channel is connected to the other end of the winding flow channel, and the other end of the second rear cover flow channel is connected to the coolant outlet.

[0035] The winding flow channel includes a liquid cooling cavity defined within the stator housing of the inner stator, where the stator core and windings of the inner stator are both located; the second cooling liquid flow channel is constructed as an electronic control board flow channel.

[0036] In one embodiment, the outer rotor includes a rotor housing and a shaft, one end of the rotor housing being open to form an open end; at least a portion of the shaft is disposed inside the rotor housing, the end of the shaft away from the open end being fixedly connected to the rotor housing, and the end of the shaft near the open end passing through a central shaft hole and extending out of the inner stator;

[0037] The motor assembly also includes a first bearing and a second bearing. The end of the shaft near the mechanical connection end is rotatably connected to the end of the inner stator facing the mechanical connection end through the first bearing, and the end of the shaft away from the mechanical connection end is rotatably connected to the end of the inner stator away from the mechanical connection end through the second bearing.

[0038] In addition, this utility model also provides a thrust assembly, comprising:

[0039] Such as the motor assembly mentioned above; and

[0040] The propeller assembly is connected to the mechanical connection point of the propeller assembly and the motor assembly.

[0041] In addition, this utility model also provides an aircraft, which includes:

[0042] Aircraft body; and

[0043] At least one thrust assembly as described above is located on the aircraft fuselage.

[0044] In one embodiment, the aircraft is an electric vertical takeoff and landing (EVTOL) aircraft.

[0045] One or more technical solutions proposed in this utility model have at least the following technical effects:

[0046] In the motor assembly technical solution of this utility model, a transmission component is added to the existing space in the inner stator of the outer rotor motor, that is, in the central shaft hole that passes through the inner stator along the axial direction of the inner stator. The transmission component connects the outer rotor to the cooling component that carries away the heat generated during motor operation. Thus, the cooling component is driven by the outer rotor in the motor assembly, eliminating the need for an independent electric drive component and the required circuit wiring structure, thereby optimizing the overall weight of the motor assembly.

[0047] In addition, the outer rotor drives the cooling component through a mechanical transmission structure, which offers higher reliability and safety compared to an independent electric drive component.

[0048] Furthermore, in this invention, the control module that provides electrical energy and transmits control signals to the variable-pitch motor is integrated into the inner stator, which facilitates the assembly of the thrust assembly, reduces assembly steps, and improves assembly efficiency. Additionally, integrating the variable-pitch motor's control module into the motor controller within the inner stator simplifies system design and improves control efficiency through a unified control architecture, reducing development and maintenance costs while enhancing the maintainability of the thrust assembly. It also facilitates redundant configuration of both components, thereby improving safety. Moreover, arranging the variable-pitch motor's control module within the inner stator allows for high integration within limited installation space and also enables better cooling by utilizing the electric motor's cooling components. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0050] Figure 1 The present invention provides a schematic diagram of a motor assembly structure, wherein the transmission component includes a transmission shaft;

[0051] Figure 2 This is an exploded view of the motor assembly provided by this utility model;

[0052] Figure 3 The present invention provides a schematic diagram of the motor assembly structure, wherein the transmission component includes an eccentric shaft;

[0053] Figure 4 An exploded view of the motor assembly provided by this utility model; wherein, the transmission component includes an eccentric shaft;

[0054] Figure 5 A schematic diagram showing the positions of the support cover, the mating gear, and the first internal gear ring in the motor assembly provided by this utility model;

[0055] Figure 6 An exploded view of the support cover, mating gear, and first internal gear ring in the motor assembly provided by this utility model;

[0056] Figure 7 A schematic diagram of the coolant flow direction of the motor assembly provided by this utility model, wherein the drive shaft or eccentric shaft is not shown;

[0057] Figure 8 A schematic diagram of the structure of the cooling pump in the motor assembly provided by this utility model; wherein, the cooling pump is an external gear pump;

[0058] Figure 9 A schematic diagram illustrating the fit between the speed regulating gear set and the external meshing gear pump provided by this utility model;

[0059] Figure 10 A schematic diagram of the structure of the cooling pump in the motor assembly provided by this utility model; wherein, the cooling pump is an internal gear pump;

[0060] Figure 11 This is a schematic diagram illustrating the cooperation between the speed regulating gear set and the internal meshing gear pump provided by this utility model.

[0061] Explanation of icon numbers:

[0062] 10. Outer rotor; 101. Mechanical connection end; 102. Open end; 11. Rotor housing; 12. Shaft; 20. Inner stator; 21. Central shaft hole; 22. First coolant flow channel; 221. First rear cover flow channel; 222. Stator base plate flow channel; 223. Winding flow channel; 224. Second rear cover flow channel; 23. Rear cover; 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; 41a. Drive shaft; 41b. Eccentric shaft; 42a. First mating part; 42b. First internal gear ring; 43. Mating gear; 441. Supporting lower cover; 4441. Lower protrusion; 442. Supporting upper cover; 4421. Upper protrusion; 45. Wiring hole; 50. Motor controller; 52. Second coolant flow channel; 60. Speed ​​regulating gear set; 61. Drive gear; 62. Output gear; 200. Pitch changer slip ring.

[0063] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0064] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0065] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0066] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0067] Motors generate a significant amount of heat during operation. Related technologies utilize various cooling methods, including air cooling (forced cooling by fans, etc.), liquid cooling (coolants such as water or oil), and combined cooling. Forced cooling involves adding a fan to the motor to forcefully dissipate heat. Liquid cooling uses a pump to drive coolant (such as water) through the motor's interior to absorb heat. Combined cooling combines air and liquid cooling to improve overall cooling efficiency. Understandably, both the fan and the pumping mechanism require additional drive structures to operate, and these drive structures necessitate additional circuitry and wiring on the motor to power the fan and pumping mechanism.

[0068] When large unmanned aerial vehicles (UAVs) and eVTOL (electric vertical take-off and landing) aircraft employ a rotor configuration, the rotor assembly and other thrust components are driven by an external rotor motor. Since the power motor is a high-power heat-generating device, the heat dissipation requirements of the thrust assembly are even higher. Therefore, the external rotor motor in the thrust assembly generally adopts a combined cooling method. However, aircraft are quite sensitive to overall weight. In this case, using an independent drive mechanism and an additional power supply architecture for the combined cooling assembly would result in a heavy overall weight for the thrust assembly, which in turn would lead to a heavy overall weight for the aircraft. Furthermore, the configuration requirements of eVTOL aircraft place high demands on space arrangement. How to meet the heat dissipation requirements of high-power heat-generating devices and rationally arrange the cooling components within a limited space has become a technical problem that urgently needs to be solved by those skilled in the art.

[0069] To address this, the present invention provides a motor assembly that adds a transmission component to the existing space in the inner stator of the outer rotor motor, i.e., the central shaft hole that passes through the inner stator along the axial direction of the inner stator. The transmission component connects the outer rotor to the cooling component that carries away the heat generated during motor operation. Thus, the cooling component is driven by the outer rotor in the motor assembly, eliminating the need for a separate electric drive component and the required circuit wiring structure, thereby optimizing the overall weight of the motor assembly.

[0070] Please see Figures 1 to 4 This embodiment proposes a motor assembly, including an outer rotor 10, an inner stator 20, a cooling assembly 30, and a transmission assembly 40.

[0071] The outer rotor 10 has one axial end as a mechanical connection end 101 and the other axial end as an open end 102. At least a portion 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. The inner stator 20 has a central shaft hole 21 that passes through the inner stator 20 along its axial direction. The cooling assembly 30 is disposed on the side of the inner stator 20 away from the mechanical connection end 101. A portion of the transmission assembly 40 is disposed in the central shaft hole 21, and the transmission assembly 40 is connected to both the outer rotor 10 and the cooling assembly 30 in a transmission manner, so that the outer rotor 10 drives the cooling assembly 30 through the transmission assembly 40.

[0072] Specifically, the motor in this embodiment is an external rotor motor. The external rotor 10 forms the outer rotor, while the inner stator 20 forms the inner stator. The inner stator 20 includes a stator housing, a rear cover 23, a stator core, and windings. The stator core is installed inside the stator housing, and the windings are embedded in the stator slots of the stator core. The stator housing is U-shaped, and its shaft hole is a central shaft hole 21, meaning the central axis of the central shaft hole 21 is collinear 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. The rear cover 23 covers the end of the stator housing facing away from the mechanical connection end 101 to prevent foreign objects from entering the motor, thus creating storage space inside the inner stator 20 for laying out corresponding circuit boards or other wiring structures. In addition, the rear cover 23 is provided with a coolant inlet and outlet, so that the coolant can be cooled from the cooling component 30 on one side of the rear cover 23 and then enter the stator housing on the other side of the rear cover 23, or the coolant can be cooled from the winding and then flow into the cooling component 30 through the rear cover 23. This will be described in detail below.

[0073] The outer rotor 10 is generally constructed as a cylindrical member with an opening on one side, forming an open end 102, through which the inner stator 20 is installed into the outer rotor 10. Multiple 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, covering one end of the inner stator 20. Correspondingly, the other side of the outer rotor 10 is a mechanical connection end 101, which is used to transmit force, motion, and torque to the outside. When the motor assembly of this embodiment serves as the drive motor for the thrust assembly of an aircraft, the mechanical connection end 101 is connected to the propeller hub to transmit power, enabling the propeller to generate the lift and thrust required for flight.

[0074] Since the central shaft hole 21 inside the inner stator 20 connects the two axial ends of the inner stator 20, and the outer rotor 10 and the cooling assembly 30 are respectively located at the two axial ends of the inner stator 20, in this embodiment, part of the transmission assembly 40 is arranged in the central shaft hole 21 and extends to the mechanical connection end to drive the transmission connection with the outer rotor 10. Another part of the transmission assembly 40 passes through the rear cover 23 and extends to the cooling assembly to drive the transmission connection with the cooling assembly 30, thereby transmitting the rotational motion of the outer rotor 10 to the cooling assembly 30 to drive the air-cooled assembly and / or liquid-cooled assembly of the cooling assembly 30 to start operation.

[0075] It is easy 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, in the central shaft hole 21 that passes through the inner stator 20 along the axial direction of the inner stator 20. The transmission assembly 40 connects the outer rotor 10 to the cooling assembly 30 that removes the heat generated during motor operation. Thus, the cooling assembly 30 is driven by the outer rotor 10 in the motor assembly, eliminating the need for a separate electric drive assembly and the required circuit wiring structure in related technologies, 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 with a mechanical transmission structure, which has higher reliability and safety compared to a separate electric drive assembly.

[0076] Furthermore, in this embodiment, most of the transmission component 40 is arranged in the central shaft hole 21 within the inner stator 20, without changing the existing structure and layout of the motor and cooling component 30 in the motor assembly, thus facilitating its widespread use in existing products.

[0077] Furthermore, this embodiment eliminates the need for a separate electric drive component required for the cooling component 30, thus avoiding the heat dissipation problems and risks associated with such a separate electric drive component.

[0078] 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, 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 a portion of the rotating shaft 12 is disposed inside the rotor housing 11. The end of the rotating shaft away from the open end is fixedly connected to the rotor housing 11, and the end of the rotating shaft 12 near the open end 102 passes through the central shaft hole 21 and extends out of the inner stator 20. The motor assembly also includes a first bearing and a second bearing. The end of the rotating shaft 12 near the mechanical connection end 101 is rotatably connected to the end of the inner stator 20 near the mechanical connection end 101 through the first bearing, and the end of the rotating shaft 12 away from the mechanical connection end 101 is rotatably connected to the end of the inner stator 20 away from the mechanical connection end 101 through the second bearing.

[0079] Specifically, a hollow tubular stator support is disposed within the central shaft hole 21 of the inner stator 20. The stator support is fixedly connected to the inner stator housing or the inner peripheral wall of the inner stator 20 via multiple protruding arms on its outer peripheral wall. One end of the stator support protrudes from the end of the inner stator 20 away from the mechanical connection end 101 and is fitted with a second bearing. A first bearing is also fitted to the end of the inner stator 20 near the mechanical connection end 101. At this time, the rotating shaft 12 of the outer rotor 10 extends into the stator support, and its two ends are respectively engaged with the first bearing and the second bearing. In this embodiment, part of the transmission assembly 40 is arranged within the stator support.

[0080] Of course, it is understandable that for aircraft, in order to reduce the overall weight and size, a single-bearing motor is preferable. The following description will also use a single-bearing motor as an example. In this case, the outer rotor 10 includes: a rotor housing 11 and a rotating shaft 12, one end of the rotor housing 11 being open to form an open end 102; at least a portion of the rotating shaft 12 is disposed inside the rotor housing 11 and fixedly connected to the other end of the rotor housing 11 to form a mechanical connection end; 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 via a bearing.

[0081] Specifically, please refer to Figure 2 The outer rotor 10's rotor housing 11 is generally constructed as a cylindrical member with an opening on one side, forming an open end 102. The outer rotor 10 also includes a rotating shaft 12, the central axis of which is collinear with the central axis of the inner stator 20. It is worth mentioning that at least a portion of the rotating shaft 12 is disposed within the rotor housing 11; for example, a portion of the rotating shaft 12 may be located within the rotor housing 11, while another portion extends out of the rotor housing 11 in a direction away from the inner stator 20.

[0082] Alternatively, please see Figure 1 and Figure 2 Alternatively, the rotating shaft 12 can be completely housed within the rotor housing 11. In this case, a cover 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 12 is housed within the rotor housing 11 and extends axially along the inner stator 20. One axial end of the rotating shaft 12 is connected to the rotor housing 11 at the cover hole by a bolt group. The other end of the rotating shaft 12 is rotatably connected to the end of the inner stator 20 facing the mechanical connection end 101 via a bearing, thus making the external rotor motor of the motor assembly provided in this embodiment a single-bearing motor. In addition, the rotating shaft 12 has a shaft hole extending through the rotating shaft 12 axially. The hole wall of the shaft hole and / or the end face of the rotating shaft 12 facing away from the inner stator 20 are provided with a connecting structure. For example, in one example, the mounting structure of the propeller system extends through the cover hole into the shaft hole and mates with the connecting structure.

[0083] In this embodiment, when the propeller system transmits the overturning moment through the connecting structure on the shaft 12, part of the overturning moment is transmitted to the rotor housing 11 through the shaft 12, and another part is transmitted to the inner stator 20 through the shaft 12 and the bearing. Since the connecting structure is located within the shaft hole, the deformation caused by the overturning moment can be resisted through structural reinforcement designs (such as increased wall thickness) at the connection points of the shaft 12, the inner stator 20, and the bearing, as well as at the connection points of the rotor housing 11 and the shaft 12 (such as increased wall thickness). Furthermore, the remaining parts of the rotor housing 11 can be designed with thin walls, thereby generating a certain amount of deformation along the transmission path when subjected to the overturning moment, thus reducing the deformation of the rotor housing 11. Of course, due to the single-bearing design, the radii of the shaft 12, the outer rotor 10, and the inner stator 20 all need to be increased to ensure structural strength. However, relatively speaking, increasing the radius also increases the propeller mounting circle radius, achieving the effect of improving the mass distribution and overturning moment distribution of the propeller system.

[0084] It is easy to understand that the single-bearing motor, with the shaft 12 located outside the central shaft hole 21, significantly reduces the overall weight of the motor assembly. Furthermore, the location of the shaft 12 outside the central shaft hole 21 allows sufficient space within the central shaft hole 21 to accommodate electronic components on the motor. Thus, in this embodiment, installing the transmission assembly 40 within the central shaft hole 21 of the single-bearing motor fully utilizes the existing space within the motor, resulting in more rational space utilization. Of course, installing the transmission assembly 40 within the central shaft hole 21, compared to leaving the central shaft hole 21 empty, also allows for a more even and rational weight distribution across the entire motor assembly.

[0085] Furthermore, since the rotating shaft 12 is located outside the central shaft hole 21, there is ample space inside the central shaft hole 21. Therefore, in one embodiment, the transmission assembly 40 includes a transmission shaft 41a, which is rotatably disposed within the central shaft hole 21 about its own central axis, and the central axis of the transmission shaft 41a is collinear with the central axis of the inner stator 20; wherein, one end of the transmission shaft 41a is connected to the rotating shaft 12 in a driving connection, and the other end of the transmission shaft 41a is connected to the cooling assembly 30 in a driving connection.

[0086] Specifically, please refer to Figure 1 The transmission assembly 40 is used to transmit the rotational movement of the rotating shaft 12 to the cooling assembly 30. Therefore, it includes a first mating portion 42a that is drively connected to the rotating shaft 12, a second mating portion that mates with the cooling assembly 30, and a transmission portion connecting the first mating portion 42a and the second mating portion. In this embodiment, the transmission portion is constructed as a transmission shaft 41a arranged coaxially with the inner stator 20, and the transmission shaft 41a rotates around its own central axis, that is, around the central axis of the inner stator 20.

[0087] It is easy to see that in this embodiment, arranging the drive shaft 41a at the central axis of the inner stator 20 can reduce the interference of the drive shaft 41a 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.

[0088] It is worth mentioning that, since the drive shaft 41a is located at the central axis of the inner stator 20, the drive shaft 41a can be directly fixedly connected to the rotating shaft 12. If the rotating shaft 12 is constructed as a cylindrical structure, one end of the drive shaft 41a is fixed to the rotating shaft 12 by welding, shaft hole fitting, or flange, etc., that is, the aforementioned first fitting part 42a and the transmission part are integrated into a drive shaft 41a.

[0089] Alternatively, when the rotating shaft 12 is provided with a rotating shaft hole extending axially through the inner stator 20 for ease of wiring, one end of the drive shaft 41a 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 via a first mating portion 42a. As an alternative, the first mating portion 42a can be constructed as a disc. For another alternative, please refer to... Figure 1 The first mating part 42a is constructed as a plurality of support arms evenly and spaced apart along the circumferential direction of the drive shaft 41a, the support arms extending to be fixedly connected to the inner circumferential wall of the rotating shaft 12. In one example, the plurality of support arms are constructed in a cross shape.

[0090] Of course, in another embodiment, please refer to Figure 3 To allow sufficient space for wiring, the transmission part of the transmission assembly 40 can be eccentrically arranged within the inner stator 20. In this case, the transmission assembly 40 includes an eccentric shaft 41b, which is rotatably disposed in the central shaft hole 21 around its own central axis. The central axis of the eccentric shaft 41b is parallel to and spaced apart from the central axis of the central shaft hole 21. One end of the eccentric shaft 41b is connected to the cooling assembly 30, and the other end of the eccentric shaft 41b is connected to the outer rotor 10, so that the outer rotor 10 drives the cooling assembly 30 through the eccentric shaft 41b.

[0091] Furthermore, the cover hole on the outer rotor 10 is used for laying corresponding cables. After the mechanical connection end 101 is connected to the actuating element (such as a propeller), one end of the cable passes sequentially through the central shaft hole 21 and the cover hole to extend to the outside of the motor assembly and connect to the corresponding cable interface on the actuating element. The other end of the cable can be connected to the control module inside the inner stator 20 for driving and controlling the actuating element. It is understood that the cable can be a power supply cable, a communication cable, or a power supply and communication combined cable, and this embodiment is not limited to this.

[0092] Furthermore, since cables are arranged within the central shaft hole 21, to avoid interference between the eccentric shaft 41b and the cables, the eccentric shaft 41b is eccentrically positioned within the central shaft hole 21. That is, the central axis of the eccentric shaft 41b is parallel to and spaced apart from the central axis of the central shaft hole 21. The eccentric shaft 41b rotates around its own central axis within the central shaft hole 21, meaning it relinquishes the axial position of the central shaft hole 21 and only occupies a portion of the space at the eccentric point. This ensures sufficient space within the central shaft hole 21 for cable routing.

[0093] Furthermore, since the eccentric shaft 41b rotates around its own central axis, and the central axis of the eccentric shaft 41b is offset from the central axis of the rotating shaft 12, a corresponding transmission structure is needed to connect the rotating shaft 12 and the eccentric shaft 41b to transmit the rotational motion of the rotating shaft 12 to the eccentric shaft 41b. It is understood that the eccentric shaft 41b and the rotating shaft 12 are transmissions between different shafts, and therefore, a gear set or transmission belt can be used. However, transmission belts or similar structures may occupy space within the rotating shaft hole, thus affecting cable routing. Therefore, in one embodiment, the motor assembly further includes a first internal gear ring 42b and a mating gear 43. The first internal gear ring 42b is fixedly connected to one end face of the rotating shaft 12 near the open end 102, and the central axis of the first internal gear ring 42b is collinear with the central axis of the rotating shaft 12; the mating gear 43 is fixedly sleeved on the other end of the eccentric shaft 41b, and the mating gear 43 meshes with the first internal gear ring 42b.

[0094] Specifically, please refer to Figure 3 and Figure 4 The first internal gear ring 42b is fixed to the end face of the rotating shaft 12 near the inner stator 20 by fasteners such as screws or welding, and the central axis of the first internal gear ring 42b is collinear with the central axis of the rotating shaft 12. A mating gear 43 meshes with the first internal gear ring 42b inside the first internal gear ring 42b, and the mating gear 43 is fixedly sleeved on the end of the eccentric shaft 41b near the rotating shaft 12. Thus, when the rotating shaft 12 rotates, it also drives the first internal gear ring 42b to rotate, and the rotation of the first internal gear ring 42b will drive the mating gear 43 to rotate around the central axis of the eccentric shaft 41b, that is, drive the eccentric shaft 41b to rotate around its own central axis.

[0095] It is easy to see that in this embodiment, since the first internal gear ring 42b is an annular component and its interior is hollow, the first internal gear ring 42b does not occupy the front and rear space in the axial direction of the shaft hole, thus leaving enough space for cable laying. In this way, the cable can pass through the first internal gear ring 42b and the cover hole in sequence and extend to the outside of the motor assembly.

[0096] It is worth mentioning that, in order to further avoid the first internal gear ring 42b affecting the cable laying, the inner diameter of the first internal gear ring 42b can be larger than the inner diameter of the rotating shaft 12, that is, the inner edge of the projection of the first internal gear ring 42b on the plane where the end face of the rotating shaft 12 is located is located radially outside the inner edge of the rotating shaft 12.

[0097] Understandably, when the motor is running, the mating gear 43 will rotate at high speed, and if the cable touches the mating gear 43, it will be damaged. Therefore, in one embodiment, the motor assembly further includes: a support cover, which is fixedly disposed at the opening of the central shaft hole 21 near the mechanical connection end 101. A portion of the surface of one end face of the support cover protrudes to form a protrusion. The protrusion has a cable routing hole 45 that passes through the support cover along the axial direction of the inner stator 20 to connect the cover hole and the central shaft hole 21. The protrusions are located radially outside the mating gear 43 and are spaced apart from each other.

[0098] Specifically, the support cover is located near the opening of the central shaft hole 21 close to the rotating shaft 12, and an eccentric shaft bearing is mounted on the support cover. The eccentric shaft bearing cooperates with the eccentric shaft 41b to allow the eccentric shaft 41b to rotate relative to the support cover. A portion of the surface of one end face of the support cover protrudes radially outward from the mating gear 43 to form a protrusion, and a wiring hole 45 for the cable to pass through is formed within the protrusion. The wiring hole 45 provides an independent wiring space. Thus, when the cable passes near the mating gear 43, it is constrained and protected by the hole wall of the wiring hole 45, thereby preventing the cable from being damaged by the high-speed rotating mating gear 43.

[0099] As an alternative to this embodiment, the support cover can be fixed to the side end face of the inner stator 20 near the mechanical connection end 101. A portion of the surface of the side end face of the support cover near the mechanical connection end 101 protrudes in a direction away from the inner stator 20 to form a protrusion. In this case, the eccentric shaft 41b passes through the support cover and extends to the side of the support cover near the rotating shaft 12 to connect with the mating gear 43.

[0100] Alternatively, as another option in this embodiment, the support cover can be constructed as a housing with an opening on one side. The housing is fixed to the end face of the inner stator 20 near the mechanical connection end 101, and the closed end of the housing protrudes into the shaft 12. A portion of the inner end face of the closed end protrudes in the direction close to the inner stator 20 to form a protrusion. In this case, an eccentric shaft bearing is installed on the inner end face of the closed end, and the eccentric shaft 41b extends outside the central shaft hole 21 until it mates with the eccentric shaft bearing. Compared to the above method, the support cover of the housing structure can also cover the shaft hole, thereby preventing foreign objects from entering the motor assembly from the shaft hole and affecting the meshing of the mating gear 43 and the first internal gear ring 42b, thereby improving the meshing reliability of the mating gear 43 and the first internal gear ring 42b.

[0101] Alternatively, as another option in this embodiment, please refer to Figure 5 and Figure 6 The support cover includes an upper support cover 442 and a lower support cover 441b. The lower support cover 441b is fixed to the side end face of the inner stator 20 near the mechanical connection end 101. A portion of the surface of the side end face of the lower support cover 441b near the mechanical connection end 101 protrudes in a direction away from the inner stator 20 to form a lower protrusion 441b1. The upper support cover 442 is located inside the rotating shaft 12 but is not connected to the rotating shaft 12. A portion of the surface of the side end face of the upper support cover 442 near the inner stator 20 protrudes in a direction close to the inner stator 20 to form an upper protrusion 4421. The upper protrusion 4421 abuts against the lower protrusion 441b1 and is fixedly connected to each other to form a protrusion. At this time, the upper support cover 442 and the lower support cover 441b define a receiving space in which the gear 43 and the eccentric shaft bearing are located. It is easy to see that, compared to the two methods mentioned above where only one side of the mating gear 43 is covered, in this embodiment, both axial ends of the mating gear 43 are covered by the upper support cover 442 and the lower support cover 441b, respectively. This further prevents foreign objects from entering the motor assembly from the shaft hole, or prevents electronic components in the inner stator 20 from falling and moving to the mating gear 43 and affecting the meshing between the mating gear 43 and the first internal gear ring 42b, thereby improving the reliability of the mating between the mating gear 43 and the first internal gear ring 42b. In addition, the cable length is always left as a margin when laying cables, meaning that the cable is not a straight line in the motor assembly, but a curve. Therefore, covering both axial ends of the mating gear 43 with the upper support cover 442 and the lower support cover 441b respectively allows the cable inside the cable routing hole 45 to be protected by the hole wall of the cable routing hole 45, while the cable near the outside of the cable routing hole 45 is protected by the upper support cover 442 and the lower support cover 441b, jointly preventing the cable from being damaged by the high-speed rotating mating gear 43.

[0102] The cross-sectional shape of the wiring hole 45 can be circular or similar. However, since the gear 43 already occupies a portion of the space defined by the shaft hole, in order to allow the wiring hole 45 to occupy more space in the remaining area to accommodate more cables, in one embodiment, please refer to... Figure 4 The wiring hole 45 is an arc-shaped hole, and part of it surrounds the gear 43.

[0103] As previously stated, the cooling assembly 30 may include an air-cooled assembly (such as a cooling fan 321), a liquid-cooled assembly (such as a heat exchanger and a pumping assembly that pumps coolant into the motor to allow coolant to flow through the motor interior), or a combination of air-cooled and liquid-cooled assemblies. If the motor assembly is configured as a drive motor for a propeller of a small unmanned aerial vehicle, the cooling assembly 30 may consist solely of an air-cooled assembly. Alternatively, if the motor assembly is configured as a drive motor for a propeller on an eVTOL, the cooling assembly 30 may be a liquid-cooled assembly or a combination of air-cooled and liquid-cooled assemblies.

[0104] In one embodiment, the inner stator 20 defines a first coolant flow channel 22, and the inner stator 20 has a coolant inlet and a coolant outlet communicating with the first coolant flow channel 22.

[0105] The cooling assembly 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 radiators are located on the side of the inner stator 20 away from the mechanical connection end 101 and spaced apart from each other. The coolant cooling channels in the radiator 322 are respectively connected to the coolant inlet and the coolant outlet to form a circulation channel with the first coolant channel 22. The cooling pump 31 is located between the radiator 322 and the inner stator 20. The cooling pump 31 is used to drive the coolant to flow in the first coolant channel 22 and the coolant cooling channel. The cooling pump 31 and the cooling fan 321 are both connected to the transmission assembly 40.

[0106] Specifically, please refer to Figure 7 The inner stator 20 defines at least one first coolant flow channel 22, and the coolant inlet and coolant outlet of the first coolant flow channel 22 are both opened on the rear cover 23. In one example, the rear cover 23 has multiple through holes, of which the one near the center of the rear cover 23 is the coolant inlet and the one near the edge of the rear cover 23 is the coolant outlet.

[0107] It is worth mentioning that the number of first coolant flow channels 22 can be one, or multiple channels connected in parallel, to reduce the length of a single first coolant flow channel 22, thereby carrying heat away from the inner stator 20 as quickly as possible. Multiple first coolant flow channels 22 can achieve uniform distribution of coolant through appropriate pipe diameter design.

[0108] Please see Figure 1 and Figure 3 The radiator assembly 32 in the cooling assembly 30 is located on the side of the rear cover 23 away from the outer rotor 10 and spaced apart from each other, thus leaving enough space for the installation of the cooling pump 31.

[0109] Specifically, the connection between the coolant heat dissipation channel, the first coolant flow channel 22, and the coolant pump 31 can be as follows: after the coolant pump 31 is connected to the coolant heat dissipation channel of the radiator 322, the coolant pump 31 is connected to the coolant inlet, while the coolant heat dissipation channel within the radiator 322 is connected to the coolant outlet. Alternatively, after the coolant pump 31 is connected to the coolant heat dissipation channel of the radiator 322, the coolant pump 31 is connected to the coolant outlet, while the coolant heat dissipation channel within the radiator 322 is connected to the coolant inlet. Alternatively, please refer to [link to relevant documentation]. Figure 7To simplify the connection and facilitate the installation of the cooling pump 31, the coolant heat dissipation channel is connected to the first coolant channel 22. The cooling pump 31 is installed on the first coolant channel 22, thereby driving the coolant flow in the first coolant channel 22, and thus promoting the coolant to circulate in the coolant heat dissipation channel and the first coolant channel 22.

[0110] The coolant exchanges heat with the outside air within the coolant heat dissipation channels. The cooling fan 321 and the radiator 322 can be arranged sequentially along the axial direction of the inner stator 20, such as with the radiator 322 closer to the inner stator 20 and the cooling fan 321 further away. Alternatively, to promote sufficient heat exchange between the outside air and the radiator 322, such as... Figure 1 and Figure 3 As shown, the cooling fan 321 is close to the inner stator 20 while the heat sink 322 is far away from the inner stator 20.

[0111] In one example, the cooling fan 321 is positioned close to the inner stator 20 while the radiator 322 is positioned away from the inner stator 20, and the cooling pump 31 is located on the first coolant flow channel 22. In this case, the cooling pump 31 drives the low-temperature coolant to flow through the first coolant flow channel 22 within the inner stator 20, absorbing heat generated by the motor, especially the windings, and becoming a high-temperature liquid to dissipate heat from the inner stator 20. After leaving the inner stator 20, the high-temperature liquid enters the radiator 322, where it exchanges heat with the outside air and becomes a low-temperature coolant, thus completing the heat dissipation cycle. The cooling fan 321 performs work on the side of the radiator 322 closest to the inner stator 20, allowing outside air to flow over the surface of the radiator 322 and undergo heat exchange. Alternatively, the cooling fan 321 can also facilitate airflow through the interior or exterior of the motor to carry away heat.

[0112] Alternatively, the radiator 322 can be connected to the inner stator 20 through an additionally designed connection structure. Or, in one embodiment, the radiator assembly 32 further includes at least three coolant pipes 323, one end of which is fixedly connected to the radiator 322 and communicates with the coolant flow channel, and the other end of which is fixedly connected to the inner stator 20 and communicates with the coolant inlet or coolant outlet. The coolant flowing through the radiator 322 enters the first coolant flow channel 22 through the coolant inlet.

[0113] Specifically, all coolant pipes 323 can be return pipes, allowing the coolant in the inner stator 20 to flow back to the radiator 322. The coolant in the radiator 322 then flows into the inner stator 20 via the cooling pump 31. Understandably, multiple coolant pipes 323 can be evenly spaced along the circumference of the inner stator 20 to improve the overall stress distribution on the motor assembly.

[0114] Alternatively, when the cooling pump 31 is installed on the first coolant flow channel 22, part of the coolant pipe 323 is an outlet pipe, and the other part of the coolant pipe 323 is a return pipe. Both the outlet pipe and the return pipe are fixedly connected to the radiator 322 and the inner stator 20, respectively. In this case, the radiator 322 includes outlet ports that are connected to the outlet pipes one by one, and return ports that are connected to the return pipes one by one. Of course, the radiator 322 also includes a pump outlet that is connected to the cooling pump 31. In addition, the number of outlet pipes and return pipes can be the same and they can be arranged in pairs. In this case, the outlet pipes and return pipes can be evenly spaced and alternately arranged along the circumference of the inner stator 20, so that the coolant can flow into the radiator from two opposite areas on the radiator 322 and flow out of the radiator from two opposite areas on the radiator 322, which is conducive to the uniform heat dissipation of the coolant in the radiator 322.

[0115] In this embodiment, the coolant pipe 323 is both a liquid pipeline and a structural component that supports and connects the radiator 322 and the inner stator 20. It is an integrated design, which improves the integration of components and reduces the number of components.

[0116] Additionally, when the cooling fan 321 is located on the side of the heat sink 322 facing the inner stator 20 and spaced apart from the heat sink 322, the number of cooling fans 321 can be one or more. Preferably, when there is only 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 drive shaft 41a is drively connected to the impeller shaft or the first gear shaft 312.

[0117] Generally, a 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 various 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 and Figure 3 The impeller shaft, which rotates around its own axis, and the first gear shaft 312, which also rotates around its own axis, are coaxial and fixedly connected to each other. Therefore, when the transmission shaft 41a is connected to either the impeller shaft or the first gear shaft 312, it can drive both the impeller shaft and the first gear shaft 312 to rotate together, thereby simultaneously driving the impeller of the cooling fan 321 and the first gear 313 of the cooling pump 31. It is evident that this embodiment eliminates the need for a separate transmission structure between the cooling fan 321 and the cooling pump 31, thus simplifying the internal mechanical structure of the motor assembly and reducing the overall weight.

[0118] Understandably, as an option in this embodiment, the impeller shaft and the first gear shaft 312 can be connected by a coupling.

[0119] Alternatively, as another option in this embodiment, please refer to Figure 1 and Figure 3 The impeller shaft and the first gear shaft 312 are integrally formed. In this case, the impeller shaft and the first gear shaft 312 are the same shaft, with one part located inside the cooling pump 31 and the other part extending through the pump body 311 of the cooling pump 31 and towards the radiator 322. The impeller of the cooling fan 321 is mounted on this other part. It is easy to understand that compared to connection methods such as couplings, the integral formation of the impeller shaft and the first gear shaft 312 can further reduce the number of parts in the motor assembly, making the axial dimension of the motor assembly smaller and further reducing the overall weight.

[0120] Furthermore, after the impeller shaft and the first gear shaft 312 are arranged coaxially, both can be offset from the central axis of the inner stator 20, i.e., eccentrically arranged, or both can be collinear with the central axis of the inner stator 20. This embodiment does not limit this. It is understood that an eccentric arrangement is beneficial for leaving space in the axial direction of the motor to arrange other components, while a collinear arrangement is beneficial for making the radial shape of the motor assembly smaller and more regular, thus facilitating its placement on platforms such as aircraft with higher aerodynamic requirements.

[0121] As previously stated, the cooling pump 31 can be either an impeller pump or a gear pump. The main working component of a gear pump is the meshing gears. When the gears rotate, the change in volume between the teeth creates suction and discharge. The pump body 311 relies on the change in working volume between the pump body 311 and the meshing gears to transport or pressurize the liquid. An impeller pump, on the other hand, relies on the impeller driving the liquid to rotate at high speed, transferring mechanical energy to the transported liquid. Because gear pumps are simple in structure, reliable in operation, and inexpensive, they are suitable for applications requiring high pressure and large flow rates. Therefore, when the motor assembly is suitable for aircraft, the cooling pump 31 can be a gear pump.

[0122] Alternatively, the cooling pump 31 is an external gear pump. 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 meshes with the first gear 313. The second gear 314 or the first gear 313 is connected to the drive shaft 41a for transmission.

[0123] Specifically, please refer to Figure 1 , Figure 8 and Figure 9The pump body 311 of the cooling pump 31 is fixed to the rear cover 23. A second gear 314 and a first gear 313 mesh with each other inside the pump body 311. Since the cooling pump 31 is closer to the drive shaft 41a or eccentric shaft 41b than the cooling fan 321, the second gear 314 of the cooling pump 31 can be driven by the drive shaft 41a or eccentric shaft 41b. The drive shaft 41a or eccentric shaft 41b drives the second gear 314 to rotate, which in turn drives the first gear 313 to rotate, thereby rotating the impeller of the cooling fan 321. Alternatively, the first gear 313 of the cooling pump 31 can be driven by the drive shaft 41a or eccentric shaft 41b. The drive shaft 41a or eccentric shaft 41b drives the first gear 313 to rotate, which in turn drives the second gear 314 to rotate, and the first gear 313 drives the impeller of the cooling fan 321 to rotate. In this embodiment, either the first gear or the second gear 314 can be used as the drive gear of the cooling pump 31, and this embodiment does not limit this.

[0124] Alternatively, as another option, the cooling pump 31 is an internal gear pump, which also includes an internal gear 315 and a first gear 313. The first gear 313 is fixedly sleeved on the first gear shaft 312, and the internal gear 315 meshes with the first gear 313. The first gear 313 is connected to the drive shaft 41a or the eccentric shaft 41b.

[0125] Generally, the main components of an internal gear pump are a pair of meshing internal gears 315 and an external gear, as well as a crescent-shaped spacer. See also... Figure 10 and Figure 11 In this embodiment, the internal gear 315 rotates around its own axis under the drive of the transmission shaft 41a. The external gear, namely the first gear 313, is sleeved on the first gear shaft 312 and is eccentrically mounted relative to the central axis of the internal gear 315, rotating under the drive of the internal gear 315. The crescent-shaped partition separates the suction chamber and the discharge chamber. During operation, when the driving internal gear 315 rotates, a partial vacuum is formed where the teeth disengage. Coolant enters the pump body 311 under atmospheric pressure and fills the spaces between the teeth. Where the teeth engage, the coolant stored between the teeth is squeezed out of the pump body 311. Of course, the first gear 313 then drives the impeller of the cooling fan 321 to rotate.

[0126] Of the two options mentioned above, the internal gear pump has a more compact structure, smaller size, and better suction performance compared to the external gear pump, making it more suitable for motor assemblies to be used on platforms such as aircraft.

[0127] Understandably, when the motor speed matches the required speed of the cooling fan 321, the drive shaft 41a or eccentric shaft 41b can be directly connected to the gear shaft and / or impeller shaft in the cooling assembly 30, i.e., no reducer or other structure is needed. Alternatively, when the motor speed is not the same as 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, which is disposed on the side of the inner stator 20 away from the mechanical connection end 101, and the transmission assembly 40 is connected to the cooling assembly 30 through the speed regulating gear set 60.

[0128] Specifically, the speed regulating gear set 60 includes multiple gears that mesh with each other. The speed regulating gear set 60 can be designed with different transmission gear ratios to increase or decrease speed, so as to match the motor speed with the speed of the cooling pump 31 and the cooling fan 321.

[0129] Understandably, the speed regulating gear set 60 can be designed with its own regulating housing, which can be fixed to the rear cover 23 by bolts or rivets, or it can be integrally formed with the rear cover 23. Then the speed regulating gear set 60 is installed in the regulating housing, wherein the drive shaft 41a or eccentric shaft 41b extends through the rear cover 23 and one side wall of the regulating housing into the regulating housing, and is coaxial and fixedly connected with the gear shaft of the drive gear 61 of the speed regulating gear set 60. The gear shaft of the output gear 62 of the speed regulating gear set 60 extends through the other side wall of the regulating housing and is coaxial and fixedly connected with the first gear shaft 312 of the cooling pump 31, or coaxial and fixedly connected with the gear shaft of the second gear 314, or it can also be coaxial and fixedly connected with the gear shaft of the internal gear 315.

[0130] Alternatively, in one embodiment, please refer to Figure 8 and Figure 11 The cooling pump 31 includes a pump body 311, which is fixedly disposed on the side of the inner stator 20 away from the mechanical connection end 101. Gear cavity 311A ​​and pump cavity 311B are sequentially defined inside the pump body 311 along the direction from the inner stator 20 to the cooling assembly 30. Pump cavity 311B is connected to the coolant inlet or coolant outlet and is connected to the circulation channel. The speed regulating gear set 60 is disposed in the gear cavity 311A.

[0131] Specifically, the pump body 311 of the cooling pump 31 is fixed to the end face of the rear cover 23 by bolts or rivets, or it can be integrally formed with the rear cover 23. Two chambers are sequentially defined within the pump body 311 along the axial direction of the inner stator 20. The chamber closer to the rear cover 23 is the gear chamber 311A, and the chamber further away from the rear cover 23 is the pump chamber 311B. The two chambers are connected to facilitate the installation of the speed regulating gear set 60 and / or the gear shaft of the cooling pump 31. Of course, to prevent the lubricating oil in the gear chamber 311A ​​from contaminating the coolant in the pump chamber 311B, a sealing ring or other sealing element can be used to seal the gear shaft traversing the two chambers.

[0132] In one example, see Figure 1 , Figure 8 and Figure 9 The speed regulating gear set 60 includes two gears, while the cooling pump 31 is an external gear pump. In this case, the gear cavity 311A ​​includes two first sub-cavities, the central axes of which are parallel and the distance between them is less than the sum of their radii. The central axis of one of the first sub-cavities is collinear with the central axis of the inner stator 20, while the other first sub-cavity is eccentrically arranged. The pump cavity 311B includes two second sub-cavities, the central axis of which 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 aforementioned first sub-cavity. The drive shaft 41a passes through the rear cover 23 and the pump body 311, extending into one of the aforementioned first sub-cavities. The driving gear 61 of the speed regulating gear set 60 is mounted on the drive shaft 41a. The output gear 62 of the speed regulating gear is installed in the other aforementioned first sub-cavity, and its gear shaft extends into the other aforementioned second sub-cavity, so that the second gear 314 is mounted on this 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 but isolated from the drive shaft 41a. Furthermore, the first gear shaft 312 extends through the pump body 311 and continues along the axial direction of the inner stator 20 in a direction away from the inner stator 20 to accommodate the impeller of the cooling fan 321. This example ensures that both the drive shaft 41a and the cooling fan 321 are arranged on the central axis of the inner stator 20, achieving a better symmetrical design of the thrust assembly.

[0133] In another example, please refer to Figure 3 , Figure 10 and Figure 11The speed regulating gear set 60 includes two gears, while the cooling pump 31 is an internal gear pump. At this time, the gear cavity 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 their radii. The central axis of one of the first sub-cavities is collinear with the central axis of the inner stator 20, while the other first sub-cavity is eccentrically arranged and collinear with the central axis of the eccentric shaft 41. The eccentric shaft 41b passes through the rear cover 23 and the pump body 311 and extends into the aforementioned other first sub-cavity. The driving gear 61 of the speed regulating gear set 60 is mounted on the eccentric shaft 41. The output gear 62 of the speed regulating gear is installed in one of the aforementioned first sub-cavities, and its gear shaft extends into the pump to connect with the internal gear 315. The first gear 313 is installed in the pump cavity 311B and mounted on the first gear shaft 312, and the central axes of both the first gear shaft 312 and the first gear are collinear with the central axis of the inner stator. Furthermore, the first gear shaft 312 extends through the pump body 311 and continues along the axial direction of the inner stator 20 in a direction away from the inner stator 20 to accommodate the impeller of the cooling fan 321. In this example, with the eccentric shaft 41 arranged eccentrically, the first gear shaft 312 and the impeller shaft are brought back to the central axis of the inner stator, achieving a better symmetrical design of the thrust assembly.

[0134] Furthermore, when the motor assembly is installed on platforms such as aircraft and used as an electric motor, it serves as the power source for the electric aircraft. Understandably, in an aircraft, during actual operation, the motor controller 50 needs to convert the onboard power input into the electrical energy required for motor drive and adjust the motor's operating parameters. Therefore, in one embodiment, the motor assembly also includes a motor controller 50, which is fixedly disposed within the central shaft hole; the motor controller 50 defines an accommodating space extending axially along the inner stator 20; wherein a portion of the transmission assembly 40 is disposed within the transmission channel.

[0135] Specifically, please refer to Figures 1 to 4 The rear cover 23 is constructed as a U-shaped shell. The open end of the rear cover 23 is fixedly connected to the stator shell of the inner stator 20 by bolts or other fasteners, together forming a space. The motor controller 50 is installed in this space. The motor controller 50 includes multiple electronic components. In order to facilitate the passage of the drive shaft 41a or the eccentric shaft 41b, and because the various electronic components inside the motor controller 50 can be spaced apart to leave sufficient space, a accommodating space extending axially along the inner stator 20 can be defined inside the motor controller 50 to accommodate the drive shaft 41a or the eccentric shaft 41b.

[0136] It is easy to see that, compared with the traditional independent electric drive components used in related technologies for the cooling components of electric motors, which are difficult to meet the safety requirements of aircraft, the electric motor provided in this embodiment drives the cooling fan and pump in the cooling component 30 through mechanical transmission structures such as drive shafts, which has higher reliability and improves the safety of the electric motor.

[0137] In addition, since the power devices inside the motor controller 50 also generate a lot of heat when it is running, in one embodiment, a second coolant flow channel 52 is defined inside the motor controller 50. The second coolant flow channel 52 is connected in series or in parallel with the first coolant flow channel 22 and then connected to the coolant heat dissipation flow channel, so that the coolant is driven by the cooling pump 31 to flow inside and carry away the heat generated inside the motor controller 50.

[0138] Understandably, when the second coolant flow channel 52 is connected in series with the first coolant flow channel 22, the second coolant flow channel 52, the first coolant flow channel 22, and the coolant heat dissipation flow channel together form a circulating flow channel. When the second coolant flow channel 52 is connected in parallel with the first coolant flow channel 22, the second coolant flow channel 52 and the first coolant flow channel 22 are respectively connected to the coolant heat dissipation flow channel, thereby forming two circulating flow channels.

[0139] In one embodiment, please refer to Figure 7 When the second coolant flow channel 52 is connected in series with the first coolant flow channel 22, the first coolant flow channel 22 includes a first rear cover flow channel 221, a stator base plate flow channel 222, a winding flow channel 223, and a second rear cover flow channel 224. One end of the first rear cover flow channel 221 is connected to the coolant inlet, and the other end of the first rear cover flow channel 221 is connected to the second coolant flow channel 52. One end of the stator base plate flow channel 222 is connected to the second coolant flow channel 52, and the other end of the stator base plate flow channel 222 is connected to one end of the winding flow channel 223. One end of the second rear cover flow channel 224 is connected to the other end of the winding flow channel 223, and the other end of the second rear cover flow channel 224 is connected to the coolant outlet.

[0140] Specifically, the portion of the stator housing of the inner stator 20 near the mechanical connection end is the stator base plate. A stator base plate flow channel 222 is defined within the stator base plate. A winding flow channel 223 is defined within the portion of the stator housing for mounting the windings.

[0141] The rear cover 23 has multiple through holes, with the one near the center of the rear cover 23 being the coolant inlet and the one near the edge of the rear cover 23 being the coolant outlet. A first rear cover flow channel 221 is formed in the end panel of the rear cover 23 away from the mechanical connection end 101. One end of the first rear cover flow channel 221 communicates with the coolant inlet, and the other end communicates with the second coolant flow channel 52. It is understood that the coolant pump 31 can be mounted on the first rear cover flow channel 221, thereby integrating the coolant pump 31 into the rear cover 23 and simplifying the connection between the coolant pump 31 and the flow channels within the motor assembly.

[0142] At least one cooling plate is disposed within the central shaft hole 21. Various power devices of the motor controller 50 are mounted on the cooling plate, such as the power module of the drive motor, the power module of the drive cooling assembly 30, the DC bus capacitor, and the control module of the pitch control assembly for controlling the propeller. The cooling plate defines a flow channel for the control board, which is also the second coolant flow channel 52.

[0143] In addition, a second rear cover flow channel 224 is also opened in the peripheral wall of the rear cover 23, and one end of the second rear cover flow channel 224 is connected to the winding flow channel 223, and the other end is connected to the coolant outlet, thereby realizing the series connection of the first coolant flow channel 22 and the second coolant flow channel 52.

[0144] Additionally, it should be noted that the winding flow channel 223 may be arranged around all windings to remove heat generated by each winding, and / or, a portion of the winding flow channel may pass through each winding along the axial direction of the inner stator 20 to facilitate rapid heat removal. Alternatively, the winding flow channel 223 may include a liquid-cooled cavity defined within the stator housing of the inner stator 20, in which both the stator core and windings of the inner stator 20 are disposed. In this way, the coolant can immerse the heat-generating components of the inner stator 20 in a submerged cooling manner, thereby improving the cooling effect.

[0145] In addition, to achieve the above objectives, this utility model also provides a thrust assembly, including: a motor assembly and a propeller assembly, wherein the propeller assembly and the motor assembly are connected by a mechanical connection end 101.

[0146] The specific structure of the motor assembly is as described in the above embodiments. Since this thrust assembly adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here. In addition, due to the weight reduction, this utility model can also improve the torque density of the thrust assembly.

[0147] The propeller assembly is connected to the mechanical connection end 101 of the motor assembly, and thus rotates under the drive of the outer rotor 10.

[0148] In one embodiment, when the transmission assembly includes a drive shaft 41a, the propeller assembly includes a hub, a variable-pitch motor, and a variable-pitch slip ring 200. The variable-pitch motor is disposed within the hub and connected to the outer rotor 10. The slip ring stator of the variable-pitch slip ring 200 is fixedly connected to the inner stator 20 and electrically connected to the connection end within the inner stator 20. The slip ring rotor of the variable-pitch slip ring 200 is fixedly connected to and electrically connected to the variable-pitch motor, thereby supplying power to the variable-pitch motor during the operation of the thrust assembly.

[0149] Please see Figure 1 In one embodiment, the slip ring stator is sleeved on one end of the drive shaft 41a near the rotating shaft 12, and the portion of the variable pitch motor can extend into the rotating shaft hole of the rotating shaft 12 and connect with the slip ring rotor, thereby placing the slip ring in the existing space of the inner stator 20 to make full use of the internal space of the motor and to reduce the overall axial dimension of the thrust assembly.

[0150] Alternatively, in another embodiment, when the transmission component includes an eccentric shaft 41b, the propeller assembly includes a hub, a variable pitch motor, and a cable. The hub is fixedly connected to the mechanical connection end 101 of the motor assembly. An axial through hole is defined inside the hub. The variable pitch motor is disposed in the axial through hole and is fixedly connected to the inner stator of the motor assembly. One end of the cable is connected to the variable pitch motor, and the other end passes through the cover hole and the shaft hole of the motor assembly and extends into the central shaft hole to connect with the control module.

[0151] Specifically, in this embodiment, the variable pitch motor is fixedly connected to the inner stator inside the propeller hub, so that the variable pitch mechanism is stationary relative to the entire propeller hub and blades. The electrical energy and control signals required for the operation of the variable pitch motor are stably transmitted through the control module inside the inner stator via cables, which improves stability compared to the variable pitch slip ring scheme in related technologies.

[0152] Furthermore, this utility model also provides an aircraft, which includes an aircraft body and at least one thrust assembly disposed on the aircraft body. The specific structure of the thrust assembly is as described in the above embodiments. Since this aircraft adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0153] The aircraft can be a drone or an electric vertical takeoff and landing (eVTOL) aircraft.

[0154] The above are merely exemplary embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the technical concept of this utility model and the contents of the specification and drawings of this utility model, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. An electric machine assembly, characterized by The application relates to a motor, comprising: an outer rotor, one axial end of which is a mechanical connection end, and the other axial end of which is an open end; an inner stator, at least a part of which extends into the outer rotor from the open end and is rotationally connected with the outer rotor, and the inner stator has a central shaft hole penetrating through the inner stator along the axial direction of the inner stator; a cooling assembly arranged on the side of the inner stator away from the mechanical connection end; and a transmission assembly, a part of which is arranged in the central shaft hole, and the transmission assembly is respectively in transmission connection with the mechanical connection end of the outer rotor and the cooling assembly, so that the outer rotor drives the cooling assembly through the transmission assembly.

2. The electric machine assembly of claim 1, wherein, The outer rotor comprises: a rotor shell, one end of which is open to form the open end; a rotating shaft, at least a part of which is arranged in the rotor shell and is fixedly connected with the other end of the rotor shell to form the mechanical connection end; wherein the rotating shaft is located outside the central shaft hole and is rotationally connected with the end of the inner stator facing the mechanical connection end through a bearing.

3. The electric machine assembly of claim 2, wherein, The transmission assembly comprises a transmission shaft, which is rotationally arranged in the central shaft hole around the central axis of the transmission shaft, and the central axis of the transmission shaft is collinear with the central axis of the inner stator; wherein one end of the transmission shaft is in transmission connection with the rotating shaft, and the other end of the transmission shaft is in transmission connection with the cooling assembly; or The transmission assembly comprises an eccentric shaft, which is rotationally arranged in the central shaft hole around the central axis of the eccentric shaft, and the central axis of the eccentric shaft is parallel to the central axis of the central shaft hole and is spaced apart from each other; wherein one end of the eccentric shaft is in transmission connection with the cooling assembly, and the other end of the eccentric shaft is in transmission connection with the outer rotor, so that the outer rotor drives the cooling assembly through the eccentric shaft.

4. The electric machine assembly of claim 3, wherein, The inner stator defines a first cooling liquid flow channel, and the inner stator has a cooling liquid inlet and a cooling liquid outlet in communication with the first cooling liquid flow channel; The cooling assembly comprises: a radiator assembly, which comprises a radiator and a cooling fan, the radiator is arranged on the side of the inner stator away from the mechanical connection end and is spaced apart from each other, and the cooling liquid heat dissipation flow channel in the radiator is in communication with the cooling liquid inlet and the cooling liquid outlet respectively, so as to form a circulating flow channel in communication with the first cooling liquid flow channel; a cooling pump arranged between the radiator and the inner stator, and the cooling pump is used to drive the cooling liquid to flow in the cooling liquid heat dissipation flow channel and the first cooling liquid flow channel; wherein the cooling pump and the cooling fan are both in transmission connection with the transmission assembly.

5. The electric machine assembly of claim 4, wherein, The radiator assembly further comprises at least three cooling liquid pipes, one end of the cooling liquid pipe is fixedly connected with the radiator and is in communication with the cooling liquid heat dissipation flow channel, the other end of the cooling liquid pipe is fixedly connected with the inner stator and is in communication with the cooling liquid inlet or the cooling liquid outlet; wherein the cooling liquid flowing through the radiator enters the first cooling liquid flow channel through the cooling liquid inlet.

6. The motor assembly of claim 4, wherein, The heat dissipation fan is located on the side of the radiator facing the inner stator and is spaced apart from the radiator, and the heat dissipation 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 is fixedly connected with each other. The transmission shaft is in transmission connection with the impeller shaft or the first gear shaft.

7. The electric machine assembly of claim 6, wherein, The impeller shaft and the first gear shaft are an integral part; and / or the central axes of the impeller shaft and the first gear shaft are collinear with the central axis of the inner stator.

8. The motor assembly of claim 6, wherein, 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 in meshing connection with the first gear, wherein the second gear or the first gear is in transmission connection with the transmission shaft or an eccentric shaft; or The cooling pump is an internal gear pump, and the cooling pump further comprises an internal gear and a first gear, the internal gear is in meshing connection with the first gear, and the first gear is fixedly sleeved on the first gear shaft; wherein the internal gear is in transmission connection with the transmission shaft or an eccentric shaft.

9. The motor assembly of claim 4, wherein, The cooling assembly further comprises: A speed regulation gear set is arranged on the side of the inner stator away from the mechanical coupling end, and the transmission assembly is in transmission connection with the cooling assembly through the speed regulation gear set.

10. The electric machine assembly of claim 9, wherein, The cooling pump comprises a pump body, the pump body is arranged on the side end face of the inner stator away from the mechanical coupling end, and a gear cavity and a pump cavity are sequentially defined in the pump body in the direction from the inner stator to the cooling assembly, and the pump cavity is connected to the circulating flow channel; The speed regulation gear set is arranged in the gear cavity.

11. The motor assembly of claim 4, wherein, The motor assembly further comprises a motor controller, the motor controller is fixedly arranged in the central shaft hole, and an accommodation space extending in the axial direction of the inner stator is defined in the motor controller; Part of the transmission assembly is arranged in the accommodation space.

12. The electric machine assembly of claim 11, wherein, A second cooling liquid flow channel is defined in the motor controller, and the second cooling liquid flow channel is in series or parallel connection with the first cooling liquid flow channel and is in communication with the cooling liquid heat dissipation flow channel.

13. The electric machine assembly of claim 12, wherein, When the second cooling liquid flow channel is in series connection with the first cooling liquid flow channel, the first cooling liquid flow channel comprises a first back cover flow channel, a stator bottom plate flow channel, a winding flow channel and a second back cover flow channel, one end of the first back cover flow channel is in communication with the cooling liquid inlet, the other end of the first back cover flow channel is in communication with the second cooling liquid flow channel, one end of the stator bottom plate flow channel is in communication with the second cooling liquid flow channel, the other end of the stator bottom plate flow channel is in communication with one end of the winding flow channel, one end of the second back cover flow channel is in communication with the other end of the winding flow channel, and the other end of the second back cover flow channel is in communication with the cooling liquid outlet; The winding flow channel comprises 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 arranged in the liquid cooling cavity; and the second cooling liquid flow channel is configured as an electric control board flow channel.

14. The motor assembly of claim 1, wherein, The outer rotor comprises a rotor shell and a rotor shaft, one end of the rotor shell is open to form the open end; at least part of the rotor shaft is arranged in the rotor shell, one end of the rotor shaft away from the open end is fixedly connected with the rotor shell, and one end of the rotor shaft close to the open end penetrates through the central shaft hole and extends out of the inner stator; The motor assembly further comprises a first bearing and a second bearing, one end of the rotor shaft close to the mechanical connection end is rotatably connected with one end of the inner stator towards the mechanical connection end through the first bearing, and one end of the rotor shaft away from the mechanical connection end is rotatably connected with one end of the inner stator away from the mechanical connection end through the second bearing.

15. A thrust assembly characterized by, Comprise: The motor assembly according to any one of claims 1 to 14; And A propeller assembly connected with the mechanical connection end of the motor assembly.

16. An aircraft, characterized in that The aircraft comprises: An aircraft body; and At least one thrust assembly according to claim 15 arranged on the aircraft body.

17. The aircraft of claim 16, wherein, The aircraft is an electric vertical take-off and landing aircraft.

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