Outer rotor electric machine, electric drive system, and electric vehicle

Abstract

This application relates to the technical field of external rotor motor equipment, disclosing an external rotor motor, an electric drive system, and an electric vehicle. The external rotor motor includes a stator assembly and a rotor assembly. The rotor assembly is sleeved on the outer periphery of the stator assembly. The stator assembly includes a support frame, windings, multiple stator cores, and multiple slot wedges. The rotor assembly is rotatably mounted on the support frame. The multiple stator cores are circumferentially spaced and fixedly mounted on the support frame. Adjacent stator cores and the support frame form receiving slots. The windings are wound around the stator cores, with at least a portion of the windings located within the receiving slots. Multiple slot wedges are correspondingly located in the multiple receiving slots. The two side edges of each slot wedge are sealed to the side walls of two adjacent stator cores facing the receiving slots. The radius of the slot wedge's side surface away from the receiving slot from its central axis is less than or equal to the radius of the outer circle of the stator assembly. This technical solution aims to solve the problem of reduced torque characteristics caused by the outer sleeve encroaching on the motor air gap in external rotor motors.

Description

Technical Field

[0001] This application belongs to the technical field of external rotor motor equipment, and particularly relates to an external rotor motor, an electric drive system, and an electric vehicle. Background Technology

[0002] Currently, rotary motors on the market include internal rotor and external rotor motors. In practical applications, external rotor motors are becoming increasingly widely used, especially as drive motors in vehicle mobility systems, such as drive motors for electric vehicles and hub external rotor motors for electric bicycles.

[0003] External rotor motors generate a significant amount of heat after prolonged power output, especially during high-power operation. A large portion of this heat originates from the resistance heat of the stator windings. In related technologies, shaft-driven motors typically employ air cooling to dissipate the heat generated by the external rotor motor. In shaft-driven motors, the stator assembly is encased in the shaft, allowing direct contact with flowing air for heat dissipation. However, in external rotor motors, the stator assembly is essentially encased and surrounded by the rotor assembly, making it difficult for flowing air to reach it. Although there is a gap between the rotor and stator assemblies (i.e., the motor air gap), this gap is usually narrow, resulting in poor heat transfer to the outside air. To address the stator assembly heat dissipation problem in external rotor motors, related technologies employ liquid cooling, where coolant immerses the windings and flows to carry away heat. All external rotor motors in related technologies use an outer sleeve fitted onto the stator assembly. This outer sleeve, along with the stator core and support frame, creates a cavity for holding the coolant. However, the outer sleeve, located between the stator assembly and the rotor assembly, encroaches on the motor's air gap, increasing it. This reduces the torque characteristics of the external rotor motor and is detrimental to improving its torque-to-weight ratio. Utility Model Content

[0004] The purpose of this application is to provide an external rotor motor, an electric drive system, and an electric vehicle, which aims to solve the problem that the outer sleeve of the external rotor motor encroaches on the air gap of the motor, resulting in a reduction in torque characteristics.

[0005] To achieve the above objectives, according to a first aspect of the embodiments of this application, an external rotor motor is provided, including a stator assembly and a rotor assembly. The rotor assembly is sleeved on the outer periphery of the stator assembly. The stator assembly includes a support frame, windings, multiple stator cores, and multiple slot wedges. The rotor assembly is rotatably mounted on the support frame. The multiple stator cores are circumferentially spaced and fixedly mounted on the support frame. The extending direction of the stator cores is parallel to the central axis direction of the external rotor motor. Adjacent stator cores and the support frame enclose a receiving groove. The windings are wound around the stator cores, and at least a portion of the windings are located within the receiving groove. The multiple slot wedges are correspondingly disposed in the multiple receiving grooves. The extending direction of the slot wedges is parallel to the extending direction of the stator cores. Along the circumference of the support frame, the two side edges of the slot wedges are respectively sealed to the side walls of the adjacent two stator cores facing the receiving groove. Furthermore, the radius of the slot wedges from the side surface away from the receiving groove to the central axis of the external rotor motor is less than or equal to the radius of the outer circle of the stator assembly.

[0006] Compared to currently available external rotor motors, the external rotor motor provided in this application eliminates the assembly structure of the outer sleeve. This external rotor motor is equipped with multiple slot wedges, each corresponding to a receiving groove formed by multiple circumferentially spaced stator cores and a support frame. The two side edges of the slot wedges are sealed to the side walls of two adjacent stator cores facing the receiving groove. In other words, the slot wedges, support frame, and two adjacent stator cores form a flow channel for coolant. The coolant in the flow channel can immerse the windings and contact the stator cores and support frame to directly absorb heat and carry it away, thereby dissipating heat from the stator assembly and achieving cooling. The slot wedges are located in the receiving grooves, and the radius of the slot wedge's side surface away from the receiving groove from the central axis of the external rotor motor is less than or equal to the radius of the outer circle of the stator assembly. This ensures that the air gap between the stator assembly and the rotor assembly is not affected by encroachment from other structures, which helps to reduce the air gap and improve the torque characteristics of the external rotor motor, thus increasing its torque-to-weight ratio.

[0007] In some embodiments, the radius of the slot wedge from the side surface of the receiving slot to the central axis of the outer rotor motor is less than or equal to the radius of the stator core from the top wall of the support frame to the central axis of the outer rotor motor. The slot wedge is located within the receiving slot and does not encroach on the motor air gap, which helps to reduce the motor air gap.

[0008] In some embodiments, the stator core has a slot on its sidewall facing the receiving slot, and the two side edges of the slot wedge are respectively engaged in the slot. This ensures stable assembly between the slot wedge and its two adjacent stator cores, improving the stability of the stator assembly.

[0009] In some embodiments, the side surface of the slot wedge away from the receiving groove includes two first abutment areas, and the side wall of the stator core facing the receiving groove includes a second abutment area. The two first abutment areas abut against the second abutment areas of two adjacent stator cores respectively. The first abutment areas and the second abutment areas abut against each other to achieve a sealing arrangement and improve the sealing performance between the slot wedge and the stator core.

[0010] In some embodiments, the stator assembly further includes at least one end member. Two end members are sleeved on the support frame. At least one of the two ends of the stator assembly along the central axis of the external rotor motor has an end member. The end members, the support frame, multiple stator cores, and multiple slot wedges together enclose an annular cavity communicating with multiple receiving slots. The annular cavity and the fluid flow channel (i.e., the receiving slot) together constitute a receiving cavity for containing coolant. The coolant flowing into the receiving cavity soaks the stator cores, the winding coils, and the support frame, absorbing heat and cooling the stator assembly, so that the motor as a whole can always maintain the temperature range of normal operation, and the motor can always be in optimal working performance.

[0011] In some embodiments, the end member includes an end ring. Along the central axis of the external rotor motor, a first end of the end ring is sealed to the end wall of the stator core and the end wall of the slot wedge, and a second end of the end ring is sealed to the support frame to enclose an annular cavity.

[0012] In some embodiments, the inner sidewall of the end ring is provided with a plurality of partition plates corresponding to a plurality of stator cores. The two ends of the partition plates along the central axis of the outer rotor motor respectively seal against the stator core and the support frame to divide the annular chamber into a plurality of sub-cavities corresponding to a plurality of receiving slots.

[0013] In some embodiments, the end member further includes a sealing sleeve, with the first end of the end ring abutting against the end wall of the stator core and the end wall of the slot wedge. The sealing sleeve is fitted at the junction of the first end of the end ring and the stator core and the slot wedge to achieve a sealing setting, which further improves the sealing stability of the mating position between the end ring and the stator core and the slot wedge, and reduces the possibility of coolant leakage.

[0014] In some embodiments, the first end of the end ring is provided with a first clearance step, the end of the stator core is provided with a second clearance step, and the end of the slot wedge is provided with a third clearance step. The first clearance step, the second clearance step, and the third clearance step form a mounting groove adapted to the sealing sleeve. The sealing sleeve is installed in the mounting groove so that the outer surface of the sealing sleeve, the outer surface of the end ring, the top wall of the stator core, and the side surface of the slot wedge are all flush. The sealing sleeve will not encroach on the motor air gap, which helps to reduce the motor air gap.

[0015] In some embodiments, the stator core has support portions at both ends along its extension direction, the support portions extending along the central axis of the external rotor motor, and the windings are wound between the support portions and the support frame. The first end of the end ring is inserted into multiple support portions. The support portions provide support and stability for the end rings, reducing the possibility of the end rings deforming and concave towards the support frame.

[0016] In some embodiments, the support frame includes a main frame and an end plate. The main frame includes a cylindrical portion and a radial wall connected to one end of the cylindrical portion. The end plate is fixedly connected to the end of the cylindrical portion away from the radial wall. The stator core is fixedly installed on the cylindrical portion. The second end of one end ring is inserted and sealed with the circumferential edge of the radial wall, and the second end of the other end ring is inserted and sealed with the circumferential edge of the end plate.

[0017] In some embodiments, the cylindrical portion is integrally formed with the radial wall.

[0018] In some embodiments, the stator assembly further includes a first sealing ring disposed between the first end of the end ring and the end wall of the stator core and the end wall of the slot wedge. The first sealing ring further seals the space between the first end of the end ring and the end wall of the stator core and the end wall of the slot wedge, improving sealing performance. And / or, the stator assembly further includes a second sealing ring, wherein a second sealing ring is disposed between the second end of one end ring and the circumferential edge of the radial wall, and a second sealing ring is disposed between the second end of the other end ring and the circumferential edge of the end plate. This makes the sealing performance between the second end of one end ring and the circumferential edge of the radial wall, and between the second end of the other end ring and the circumferential edge of the end plate, more stable and reliable, further reducing the possibility of coolant leakage.

[0019] In some embodiments, the rotor assembly has a power output end rotatably mounted on an end plate; the external rotor motor further includes a pump device and a connecting shaft. The pump device has an input end, an output end, and a power connection end. A support frame has a hollow cavity, and the pump device is installed in the hollow cavity. The connecting shaft is rotatably mounted on the support frame, and the central axis of the connecting shaft is colinear with the central axis of the rotor assembly. The connecting shaft has a first end and a second end. The power output end is driven to the first end, and the second end passes through the end plate and extends into the hollow cavity, where it is driven to the power connection end. The receiving chamber has a first interface and a second interface, with the input end communicating with the first interface and the output end communicating with the second interface. The pump device pumps the coolant, enabling the coolant to circulate and flow through the receiving chamber to dissipate heat from the coils and stator core, thereby improving the efficiency of coolant heat dissipation.

[0020] In some embodiments, the pump device is a rotary pump, which includes a pump casing, a pump stator, and a pump rotor. The pump stator is fixedly disposed within the pump casing and has a pump cavity. Both the input and output ends are located within the pump casing and communicate with the pump cavity. The pump rotor serves as the power connection end and is disposed within the pump cavity. The rotor assembly drives the pump rotor to rotate within the pump cavity to pump coolant. The rotary pump has a compact overall size, which can be well adapted to the narrow and limited hollow cavity of the support frame, facilitating the miniaturization and optimization design of the motor.

[0021] In some embodiments, the external rotor motor further includes a heat dissipation device having a heat dissipation channel with an inlet end and an outlet end. The inlet end is connected to the output end, and the outlet end is connected to a second interface. The heat dissipation device enables rapid cooling of the high-temperature coolant, thereby improving the cooling efficiency of the coolant.

[0022] According to a second aspect of an embodiment of this application, an electric drive system is provided. The electric drive system includes a battery, a control module connected to the battery, and an external rotor motor as described above, with windings electrically connected to the control module.

[0023] According to a third aspect of the embodiments of this application, an electric vehicle is provided. The electric vehicle includes an external rotor motor as described above; or, the electric vehicle includes an electric drive system as described above. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, 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. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a front view schematic diagram of an external rotor motor according to an embodiment of this application;

[0026] Figure 2 for Figure 1 Cross-sectional view along the AA direction;

[0027] Figure 3 This is a front view schematic diagram of the stator assembly of an external rotor motor according to an embodiment of this application;

[0028] Figure 4 for Figure 3 Cross-sectional view along the middle BB direction;

[0029] Figure 5 for Figure 4 Enlarged view of point J;

[0030] Figure 6 for Figure 3 Cross-sectional view along the CC direction;

[0031] Figure 7 for Figure 6 Enlarged view of point S in the middle;

[0032] Figure 8 This is a schematic diagram of the assembly structure of the jig, stator core, winding, slot wedge and insulating paper of the stator assembly of the external rotor motor according to an embodiment of this application;

[0033] Figure 9 This is a schematic diagram of the assembly structure of the insulating paper of the stator assembly of an external rotor motor according to an embodiment of this application;

[0034] Figure 10 A perspective view of the slot wedge of the stator assembly of an external rotor motor according to an embodiment of this application;

[0035] Figure 11 This is a schematic diagram of the assembly structure of the rotor assembly of an external rotor motor according to an embodiment of this application;

[0036] Figure 12 This is a cross-sectional schematic diagram of the rotor assembly of an external rotor motor according to an embodiment of this application;

[0037] Figure 13 for Figure 12 Cross-sectional view along the DD direction;

[0038] Figure 14 This is a front view schematic diagram of a pump device with an external rotor motor according to an embodiment of this application;

[0039] Figure 15 for Figure 14 Cross-sectional view along the EE direction;

[0040] Figure 16 for Figure 15 Cross-sectional view along the FF direction;

[0041] Figure 17 This is a schematic diagram of the structure of an end ring of an external rotor motor according to an embodiment of this application;

[0042] Figure 18 This is a schematic diagram of the structure of an electric vehicle according to an embodiment of this application.

[0043] The figures in the diagram are labeled as follows:

[0044] 10. Stator assembly; 11. Support frame; 110. Main frame; 111. Cylindrical section; 112. Radial wall; 113. End plate; 114. Hollow cavity; 12. Stator core; 121. Top wall; 122. Side wall; 123. Slot; 124. Second abutment area; 125. Second clearance step; 126. Support part; 13. Winding; 14. Slot wedge; 141. Side edge; 142. Side surface; 143. First abutment area; 144. End wall; 145. Third clearance step; 15. Receiving chamber; 151. First interface; 152. Second interface; 16. End component; 161. End ring; 1611. First clearance step; 1612. Separator; 162. Sealing sleeve; 17. Mounting groove; 181. First sealing ring; 182. Second sealing ring; 19. Receiving groove;

[0045] 20. Rotor assembly; 21. Rotor housing; 22. Magnet; 23. Power output end; 24. Housing cover;

[0046] 31. Fixture; 32. Insulating paper;

[0047] 40. Pump assembly; 41. Pump stator; 411. Input end; 412. Output end; 413. Pump chamber; 414. Inlet chamber; 415. Outlet chamber; 42. Pump rotor; 43. First pump casing; 44. Second pump casing; 45. Pump casing;

[0048] 50. Connecting shaft; 51. First end of connecting shaft; 52. Second end of connecting shaft;

[0049] 60. Heat dissipation device; 61. Heat dissipation channel; 62. Liquid inlet; 63. Liquid outlet;

[0050] 81. First bearing; 82. Second bearing; 83. Piping; 84. Third bearing;

[0051] 90. Electric vehicle; 91. Drive motor; 92. Battery unit; 93. Control module; 94. Frame; 95. Wheel. Detailed Implementation

[0052] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0053] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0054] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0055] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0056] External rotor motors generate a significant amount of heat after prolonged power output, especially during high-power operation. A large portion of this heat originates from the resistance heat of the stator windings. In related technologies, for external rotor motors, the stator is essentially enclosed and surrounded by the rotor assembly, making it difficult for flowing air to contact the stator. Furthermore, the gap between the rotor and stator assemblies (i.e., the motor air gap) is relatively narrow, resulting in poor heat dissipation through the air gap. Related technologies employ liquid cooling, where coolant immerses the windings and flows to dissipate heat, thus achieving temperature reduction.

[0057] However, all related external rotor motors use an outer sleeve fitted onto the stator assembly to create a cavity for holding the coolant, which, together with the stator core and support frame, encloses the coolant. However, the outer sleeve, located between the stator and rotor assemblies, encroaches on the motor's air gap, increasing it. This reduces the torque characteristics of the external rotor motor and is detrimental to improving its torque-to-weight ratio.

[0058] Based on the above considerations, embodiments of this application provide an external rotor motor that effectively solves the problem of reduced torque characteristics caused by the encroachment of the outer sleeve on the motor air gap. Compared to currently available external rotor motors, the external rotor motor provided in this application eliminates the assembly structure of the outer sleeve. This external rotor motor is provided with multiple slot wedges, which are correspondingly located in a receiving groove surrounded by multiple circumferentially spaced stator cores and support frames. The two side edges of the slot wedges are respectively sealed to the side walls of two adjacent stator cores facing the receiving groove. That is, the slot wedges, support frames, and two adjacent stator cores form a flow channel for coolant to flow. The coolant in the flow channel can immerse the windings and contact the stator cores and support frames to directly absorb heat and carry it away, thereby dissipating heat from the stator assembly and achieving cooling. The slot wedge is located in the receiving slot, and the radius of the side surface of the slot wedge away from the receiving slot to the central axis of the outer rotor motor is less than or equal to the radius of the outer circle of the stator assembly. This ensures that the air gap between the stator assembly and the rotor assembly is not affected by the encroachment of other structures, which helps to reduce the air gap and improve the torque characteristics of the outer rotor motor, thereby improving the torque-to-weight ratio of the outer rotor motor.

[0059] To illustrate the technical solutions provided by the embodiments of this application, the following detailed description is provided in conjunction with specific drawings and embodiments.

[0060] Explanation: The "central axis of the external rotor motor" refers to the central axis formed by the three-dimensional structure of the multiple stator cores 12 when they are circumferentially fixed on the support frame 11. This central axis is the central axis of the external rotor motor. Furthermore, when the rotor assembly 20 is fitted onto the outer periphery of the stator assembly 10, the central axis of the rotor assembly 20 and the central axis of the external rotor motor are located on the same straight line, that is, the central axis of the rotor assembly 20 and the central axis of the external rotor motor are coaxially arranged.

[0061] According to a first aspect of the embodiments of this application, embodiments of this application provide an external rotor motor. For example... Figures 1 to 6As shown, the external rotor motor includes a stator assembly 10 and a rotor assembly 20, with the rotor assembly 20 fitted around the outer periphery of the stator assembly 10. The stator assembly 10 includes a support frame 11, windings 13, multiple stator cores 12, and multiple slot wedges 14. The support frame 11 provides assembly support for the rotor assembly 20 and the multiple stator cores 12; that is, the rotor assembly 20 is rotatably mounted on the support frame 11, and the multiple stator cores 12 are circumferentially spaced and fixedly mounted on the support frame 11, with the extension direction of the stator cores 12 parallel to the central axis of the external rotor motor. Adjacent stator cores 12 and the support frame 11 form a receiving groove 19, and the windings 13 are wound around the stator cores 12, with at least a portion of the windings 13 located within the receiving groove 19. Multiple slot wedges 14 are correspondingly disposed in multiple receiving slots 19. The extending direction of the slot wedges 14 is parallel to the extending direction of the stator core 12. Along the circumference of the support frame 11, the two side edges 141 of the slot wedges 14 are respectively sealed to the side walls 122 of the two adjacent stator cores 12 facing the receiving slots 19. Furthermore, the radius of the slot wedges 14 from the side surface 142 away from the receiving slots 19 to the central axis of the outer rotor motor is less than or equal to the radius of the outer circle of the stator assembly 10.

[0062] Compared to the external rotor motors currently on the market, the external rotor motor provided in this application eliminates the assembly structure of the outer sleeve. The external rotor motor is provided with multiple slot wedges 14, which are correspondingly arranged in a receiving groove 19 surrounded by multiple circumferentially spaced stator cores 12 and support frames 11. The two side edges 141 of the slot wedges 14 are respectively sealed to the side walls 122 of the adjacent two stator cores 12 facing the receiving groove 19. That is, the slot wedges 14, support frames 11 and adjacent two stator cores 12 surround a liquid flow channel for coolant to flow. The coolant in the liquid flow channel can immerse the winding 13 and contact the stator cores 12 and support frames 11 to directly absorb heat and flow away heat, thereby dissipating heat from the stator assembly 10 and achieving cooling. The slot wedge 14 is provided in the receiving groove 19, and the radius of the side surface 142 of the slot wedge 14 away from the receiving groove 19 to the central axis of the outer rotor motor is less than or equal to the radius of the outer circle of the stator assembly 10. This ensures that the motor air gap between the stator assembly 10 and the rotor assembly 20 is not affected by the encroachment of other structures, which helps to reduce the motor air gap, thereby improving the torque characteristics of the outer rotor motor and improving the torque-to-weight ratio of the outer rotor motor.

[0063] The air gap in an external rotor motor refers to the thin layer of air gap between the stator assembly 10 and the rotor assembly 20. Specifically, it refers to the minimum distance between the stator assembly 10 and the rotor assembly 20, meaning the radius of the inner circle of the rotor assembly 20 is slightly larger than the radius of the outer circle of the stator assembly 10. The air gap prevents motion interference when the rotor assembly 20 rotates relative to the stator assembly 10 and also affects the electrical performance, electromagnetic performance, efficiency, and noise of the external rotor motor. Among these factors, the air gap has the most direct and significant impact on the electromagnetic performance between the stator assembly 10 and the rotor assembly 20. That is, the smaller the air gap, the stronger the electromagnetic induction of the rotor assembly 20 under the influence of the magnetic flux of the stator assembly 10; conversely, the larger the air gap, the weaker the electromagnetic induction of the rotor assembly 20 under the influence of the magnetic flux of the stator assembly 10.

[0064] The outer circle of the stator assembly 10 refers to the outer circle of the cross-sectional profile of the stator assembly 10 perpendicular to the central axis of the outer rotor motor. The inner circle of the rotor assembly 20 refers to the inner circle of the cross-sectional profile of the rotor assembly 20 perpendicular to the central axis of the outer rotor motor.

[0065] In the external rotor motor, the winding 13 is wound and accommodated within the receiving slot 19, meaning the winding 13 does not completely fill the receiving slot 19. Specifically, along the radial direction of the stator assembly 10, the stator core 12 is higher than the top wall 121 of the support frame 11 than the winding 13. In this embodiment, along the radial direction of the stator assembly 10, the radius of the outer circle of the stator assembly 10 is the vertical distance from the highest point of the top wall 121 of the stator core 12 to the central axis of the external rotor motor. Furthermore, the radius of the slot wedge 14 from the side surface 142 of the receiving slot 19 to the central axis of the external rotor motor is less than or equal to the radius of the stator core 12 from the top wall 121 of the support frame 11 to the central axis of the external rotor motor. In other words, the slot wedge 14 is located within the receiving slot 19 and does not encroach on the motor air gap, which helps to reduce the motor air gap, thereby improving the torque characteristics of the external rotor motor and increasing its torque-to-weight ratio.

[0066] like Figures 11 to 13As shown, the rotor assembly 20 includes a rotor housing 21 and multiple magnets 22. The rotor housing 21 is a cylindrical shell, and the magnets 22 are elongated strips. Multiple magnets 22 are circumferentially spaced and fixed to the inner wall of the rotor housing 21, with the length extension direction of the magnets 22 parallel to the central axis of the rotor housing 21. The minimum distance between the magnets 22 and the top wall 121 (or the highest point of the winding 13) of the stator core 12 of the stator assembly 10 is the motor air gap. Furthermore, the distances between each magnet 22 and the top wall 121 (or the highest point of the winding 13) of the stator core 12 of the stator assembly 10 are substantially equal. That is, the motor air gap between the rotor assembly 20 and the stator assembly 10 is circumferentially uniform around the central axis of the external rotor motor. This is beneficial for improving the electrical performance, electromagnetic performance, and efficiency of the external rotor motor, as well as for reducing the overall noise level of the external rotor motor. In an external rotor motor, when the winding 13 is radially higher than the stator core 12, the air gap is the minimum distance between the winding 13 and the magnet 22. Of course, in a typical external rotor motor, the radial height of the winding 13 is less than the radial height of the stator core 12. Therefore, the air gap generally refers to the minimum distance between the stator core 12 and the magnet 22.

[0067] In the embodiments of this application, the slot wedge 14 is made of a non-metallic material. After the slot wedge 14 is assembled with two adjacent stator cores 12, good insulation between the non-metallic slot wedge 14 and the stator cores 12 can be guaranteed.

[0068] like Figure 4 and Figure 5 As shown, in some embodiments, the stator core 12 has a slot 123 on the side wall 122 facing the receiving slot 19, and the two side edges 141 of the slot wedge 14 are respectively engaged in the slot 123. This makes the assembly of the slot wedge 14 with the two adjacent stator cores 12 stable, so that the coolant flowing in the liquid flow channel will not dislodge the slot wedge 14 from the two adjacent stator cores 12, thereby improving the stability of the stator assembly 10. In addition, the slot 123 can squeeze the side edges 141 of the slot wedge 14 to a certain extent, thereby achieving a sealing between the side edges 141 of the slot wedge 14 and the stator core 12, so that the slot wedge 14, the support frame 11 and the two adjacent stator cores 12 form a liquid flow channel for the coolant to flow. In this way, the flowing coolant can absorb and carry away the heat of the winding 13, the stator core 12 and the support frame 11, thereby achieving heat dissipation and cooling.

[0069] like Figure 5 and Figure 10As shown, the slot wedge 14, on its side surface 142 away from the receiving groove 19, includes two first abutment regions 143, and the stator core 12, on its side wall 122 facing the receiving groove 19, includes a second abutment region 124. The two first abutment regions 143 respectively abut against the second abutment regions 124 of two adjacent stator cores 12, thereby confining the slot wedge 14 within the receiving groove 19. Furthermore, the first abutment regions 143 and the second abutment regions 124 abut against each other to achieve a sealing arrangement, so that the slot wedge 14, the support frame 11, and the two adjacent stator cores 12 enclose a fluid flow channel for coolant flow. In some embodiments, the two side edges 141 of the slot wedge 14 may respectively abut against the winding 13. Alternatively, in other embodiments, the two side edges 141 of the slot wedge 14 may be respectively embedded in the slot 123. In this way, the slot 123 can compress the side edges 141 to form a first seal, and the first abutting area 143 and the second abutting area 124 abut against each other to form a second seal, thereby improving the sealing performance between the slot wedge 14 and the stator core 12.

[0070] like Figure 2 , Figure 3 , Figure 6 and Figure 7 As shown, in some embodiments, the stator assembly 10 further includes at least one end member 16, which is sleeved on the support frame 11. The stator assembly 10 has end members 16 at at least one of its two ends along the central axis of the external rotor motor. The end members 16, the support frame 11, multiple stator cores 12, and multiple slot wedges 14 together enclose an annular chamber communicating with multiple receiving slots 19. This annular chamber and the fluid flow channel (i.e., the receiving slot 19) constitute a receiving chamber 15 for containing coolant. Thus, the coolant flowing into the receiving chamber 15 soaks the stator cores 12, the coils of the windings 13, and the support frame 11 to absorb the heat generated by the stator assembly 10 and achieve heat exchange, thereby absorbing heat and cooling the stator assembly 10. The flowing coolant promptly carries away the heat, preventing heat accumulation and ensuring that the entire motor can always maintain its normal operating temperature range, allowing the motor to always operate at its optimal performance.

[0071] In some embodiments of the external rotor motor, the stator assembly 10 has an end member 16 at only one end along the central axis of the external rotor motor, and the end faces of the stator core 12 and the slot wedge 14 at the other end are fitted with and sealed to the support frame 11.

[0072] In some embodiments, the external rotor motor includes two end members 16, that is, the two ends of the stator assembly 10 along the central axis of the external rotor motor each form an annular cavity through an end member 16. The following description uses an external rotor motor including two end members 16 as an example.

[0073] In some embodiments, such as Figure 2 , Figure 3 , Figure 6 , Figure 7 and Figure 17 As shown, the end member 16 includes an end ring 161. Along the central axis of the external rotor motor, the first end of the end ring 161 is sealed to the end wall of the stator core 12 and the end wall 144 of the slot wedge 14, and the second end of the end ring 161 is sealed to the support frame 11. That is, by sealing both ends of the fluid flow channel with the two end rings 161, two annular chambers are formed. These two annular chambers and the fluid flow channel constitute a receiving chamber 15 for containing coolant. Furthermore, since the outer surface of the end ring 161 is flush with or lower than the top wall of the stator core 12 and the side surface 142 of the slot wedge 14, the end ring 161 will not encroach on the motor air gap, which helps to reduce the motor air gap and thus improve the torque characteristics of the external rotor motor, thereby increasing the torque-to-weight ratio of the external rotor motor.

[0074] In the embodiments of this application, the outer surface of the end ring 161 is flush with the top wall 121 of the stator core 12 and the side surface 142 of the slot wedge 14.

[0075] In some embodiments, multiple receiving chambers 15 are interconnected, meaning the annular chamber formed by the end rings 161 is an annular interconnected space. In this embodiment, after the coolant flows into the space formed by one of the end rings 161, it is diverted into each receiving chamber 15. After the coolant absorbs heat from the coils of the corresponding winding 13 and the stator core 12 in each receiving chamber 15, the coolant converges into the space formed by the other end ring 161 and flows out. Thus, the coolant dissipates heat and cools the stator assembly 10, ensuring that the entire motor can always maintain a normal operating temperature range and thus maintain optimal operating performance.

[0076] In some embodiments, such as Figure 17As shown, by providing multiple partition plates 1612 corresponding one-to-one with multiple stator cores 12 on the inner side of the end ring 161, and sealing and abutting the stator core 12 and the support frame 11 at both ends along the central axis of the external rotor motor, the multiple partition plates 1612 divide the annular chamber into multiple sub-cavities corresponding one-to-one with multiple receiving grooves 19, thereby forming multiple independent receiving chambers 15 with multiple fluid flow channels. The coolant in each receiving chamber 15 flows independently, and the coolant in each receiving chamber 15 only absorbs heat and carries it away from the coil of the winding 13 located in that receiving chamber 15 and the two adjacent stator cores 12 corresponding to that receiving chamber 15. The cooling effect of the coolant in any two receiving chambers 15 is independent and does not affect each other. The coolant in each receiving chamber 15 independently dissipates heat and cools the coil of the corresponding winding 13 and the stator core 12, and the cooling target is clearly defined. In other words, each receiving chamber 15 is an independent flow path, which makes it easy to independently control the flow rate of the coolant in each receiving chamber 15 and independently detect the temperature rise, thereby improving the heat dissipation and cooling effect on the stator assembly 10.

[0077] To further seal the mating position between the end ring 161 and the stator core 12 and slot wedge 14, such as Figure 3 and Figure 7 As shown, in some embodiments, the end member 16 further includes a sealing sleeve 162. The first end of the end ring 161 abuts against the end wall of the stator core 12 and the end wall 144 of the slot wedge 14. The sealing sleeve 162 is fitted onto the junction of the first end of the end ring 161 and the stator core 12 and the slot wedge 14 to achieve a sealing configuration. Thus, by providing the sealing sleeve 162, the sealing stability of the mating position between the end ring 161 and the stator core 12 and the slot wedge 14 is further improved, reducing the possibility of coolant leakage.

[0078] In some embodiments, such as Figure 7 , Figure 10 and Figure 17As shown, the first end of the end ring 161 is provided with a first clearance step 1611, the end of the stator core 12 is provided with a second clearance step 125, and the end of the slot wedge 14 is provided with a third clearance step 145. The first clearance step 1611, the second clearance step 125, and the third clearance step 145 form an installation groove 17 adapted to the sealing sleeve 162. The sealing sleeve 162 is installed in the installation groove 17. While achieving a further sealing effect at the mating position between the end ring 161, the stator core 12, and the slot wedge 14, the sealing sleeve 162 also ensures that the outer surface of the sealing sleeve 162, the outer surface of the end ring 161, the top wall 121 of the stator core 12, and the side surface 142 of the slot wedge 14 are all flush. In this way, the sealing sleeve 162 will not encroach on the motor air gap, which helps to reduce the motor air gap, thereby improving the torque characteristics of the external rotor motor and increasing the torque-to-weight ratio of the external rotor motor.

[0079] like Figure 2 , Figure 6 and Figure 7 As shown, in some embodiments, the stator core 12 has support portions 126 at both ends along its extension direction. The support portions 126 extend along the central axis of the external rotor motor, and the winding 13 is wound between the support portions 126 and the support frame 11. The first end of the end ring 161 is inserted into multiple support portions 126. In this embodiment, multiple support portions 126 located at the same end of the stator assembly 10 provide support and stability for the end ring 161, reducing the possibility of the end ring 161 deforming into the support frame 11. Furthermore, the support portions 126 cooperate with the sealing sleeve 162 to clamp and position the end ring 161, making the end ring 161 more stable and reliable after assembly.

[0080] In some embodiments, the support portion 126 may be a cantilever structure integrally extended from the stator core 12. Alternatively, in other embodiments, such as Figure 2 , Figures 4 to 9 As shown, in order to ensure the insulation between the winding 13 and the stator core 12, the stator core 12 needs to be covered with insulating paper 32 and the winding 13 is wound on the insulating paper 32. Then the support part 126 can be a cantilever structure extending from the insulating paper 32.

[0081] In some embodiments, the sealing sleeve 162 may be an integral component made of a high-strength material and injection molded. Alternatively, in other embodiments, the sealing sleeve 162 may be made of fibrous material (e.g., wound carbon fiber filaments), and the wound fibrous material may be formed into a cylindrical component by adhesive or hot-melt processes. The following description uses the example of the sealing sleeve 162 being an integral component made of a high-strength material and injection molded.

[0082] like Figure 2 , Figure 3 and Figure 6 As shown, in some embodiments, the support frame 11 includes a main frame 110 and an end plate 113. The main frame 110 includes a cylindrical portion 111 and a radial wall 112 connected to one end of the cylindrical portion 111. The end plate 113 is fixedly connected to the end of the cylindrical portion 111 away from the radial wall 112. The stator core 12 is fixedly installed on the cylindrical portion 111. The second end of one end ring 161 is inserted and sealed with the circumferential edge of the radial wall 112, and the second end of the other end ring 161 is inserted and sealed with the circumferential edge of the end plate 113. In this embodiment, the support frame 11 can be a split structure, that is, the cylindrical portion 111, the radial wall 112, and the end plate 113 can be three independent components, which are assembled to form the support frame 11. When assembling the stator assembly 10, the cylindrical portion 111, stator core 12, winding 13, and slot wedge 14 are first assembled into a ready-to-use module (in this embodiment, the stator core 12 is directly fixedly installed on the cylindrical portion 111, which is a component made of non-metallic material). Then, two sealing sleeves 162 are respectively fitted onto the cylindrical portion 111 and sealed and connected with the stator core 12 and slot wedge 14. Next, two end rings 161 are respectively fitted onto the cylindrical portion 111 and sealed and connected with the sealing sleeves 162. Finally, the radial wall 112 and end plate 113 are respectively installed at both ends of the cylindrical portion 111, with the radial wall 112 sealingly abutting against one of the end rings 161 and the end plate 113 sealingly abutting against the other end ring 161, thereby assembling and forming the stator assembly 10. This helps to reduce assembly difficulty and improve assembly efficiency.

[0083] In other embodiments, the cylindrical portion 111 and the radial wall 112 may be integrally formed. The assembly steps of the stator assembly 10 in this embodiment differ from the assembly steps of the separate support frame 11 described above. The assembly steps of the stator assembly 10 in this embodiment are as follows: multiple stator cores 12 are assembled into a circle using a jig 31, and the winding 13 is wound around them, such as... Figure 2 , Figure 4 , Figure 6 and Figure 8 The fixture 31 shown is a component made of non-metallic material. In this case, the main frame 110 can be a component made of either metallic or non-metallic material. Then, one end ring 161 is fitted onto the cylindrical portion 111 and abuts against the radial wall 112. Next, one sealing sleeve end ring 161 is fitted onto the cylindrical portion 111 and mated with the end ring 161. Finally, multiple stator cores 12 and windings 13 are assembled onto the cylindrical portion 111 using the fixture 31 (e.g., ...). Figure 2 , Figure 4 and Figure 6(As shown), next, another sealing sleeve 162 and another end ring 161 are sequentially fitted onto the cylinder 111, and finally the end plate 113 is installed on the end of the cylinder 111 away from the radial wall 112. The end plate 113 is locked onto the cylinder 111 along the central axis of the outer rotor motor by bolts. The end plate 113 then applies an axial force to the end ring 161 it abuts against. Under the action of the axial force, a sealing arrangement is achieved between the radial wall 112 and one of the end rings 161, between each end ring 161 and the sealing sleeve 162, between each end ring 161 and the stator core 12 and the slot wedge 14, and between the other end ring 161 and the end plate 113.

[0084] like Figure 6 and Figure 7 As shown, in some embodiments, the stator assembly 10 further includes a first sealing ring 181, which is disposed between the first end of the end ring 161 and the end wall of the stator core 12 and the end wall 144 of the slot wedge 14. Thus, the first sealing ring 181 further seals the space between the first end of the end ring 161 and the end wall of the stator core 12 and the end wall 144 of the slot wedge 14, improving sealing performance and further reducing the possibility of coolant leakage.

[0085] like Figure 6 and Figure 7 As shown, in some embodiments, the stator assembly 10 further includes a second sealing ring 182. A second sealing ring 182 is provided between the second end of one end ring 161 and the circumferential edge of the radial wall 112, thereby making the sealing performance between the second end of one end ring 161 and the circumferential edge of the radial wall 112 more stable and reliable, further reducing the possibility of coolant leakage. A second sealing ring 182 is provided between the second end of the other end ring 161 and the circumferential edge of the end plate 113, thereby making the sealing performance between the second end of the other end ring 161 and the circumferential edge of the end plate 113 more stable and reliable, further reducing the possibility of coolant leakage.

[0086] In some embodiments, the rotor assembly 20 has a power output end 23, which is integrally formed with the rotor housing 21. The power output end 23 is rotatably disposed on the end plate 113. After the rotor assembly 20 is sleeved on the stator assembly 10, a cover 24 is fixedly covered at the end of the rotor housing 21 away from the power output end 23. The cover 24 is rotatably connected to the support frame 11 through a third bearing 84. The cover 24 closes the opening of the rotor housing 21, so that the stator assembly 10 is wrapped and sealed by the rotor housing 21, the power output end 23 and the cover 24, preventing dust, debris, water droplets and other debris from entering the rotor housing 21 and contaminating the stator assembly 10. The power output end 23 is assembled with the support frame 11 via a first bearing 81. The first bearing 81 can be a radial bearing (e.g., a deep groove ball bearing, a cylindrical roller bearing, a bearing bush, etc.) or an axial bearing (e.g., a thrust ball bearing, a thrust cylindrical roller bearing, etc.). Preferably, the first bearing 81 is a radial bearing. Thus, the support frame 11 supports the rotor assembly 20, and the rotor assembly 20 rotates around the central axis of the main frame 110 of the support frame 11. Figure 1 , Figure 2 , Figures 14 to 16As shown, the external rotor motor also includes a pump device 40 and a connecting shaft 50. The pump device 40 has an input end 411, an output end 412 and a power connection end. The support frame 11 is provided with a hollow cavity 114. The pump device 40 is installed in the hollow cavity 114. The connecting shaft 50 is rotatably installed on the support frame 11 via a second bearing 82. The second bearing 82 can be a radial bearing (e.g., a deep groove ball bearing, a cylindrical roller bearing, a bearing bush, etc.) or an axial bearing (e.g., a thrust ball bearing, a thrust cylindrical roller bearing, etc.). Preferably, the second bearing 82 is a radial bearing. The outer ring of the second bearing 82 is interference-fitted into the hollow cavity 114. The inner ring of the second bearing 82 and the connecting shaft 50 are configured to rotate synchronously (either through interference fit or by key connection). The central axis of the connecting shaft 50 is collinear with the central axis of the rotor assembly 20. The connecting shaft 50 has a first end 51 and a second end 52. The power output end 23 is driven to the first end 51 of the connecting shaft. The second end 52 of the connecting shaft passes through the end plate 113 and extends into the hollow cavity 114, where it is driven to the power connection end. The receiving chamber 15 has a first interface 151 and a second interface 152. The input end 411 and the first interface 151 are directly connected through a pipe 83 (which can be a plastic hose or a metal pipe). The output end 412 and the second interface 152 can be directly connected through a heat dissipation corrugated pipe, or an independent heat dissipation device can be set between the output end 412 and the second interface 152 so that the output end 412 and the second interface 152 are indirectly connected through the heat dissipation device. This allows the high-temperature coolant flowing out from the receiving chamber 15 to quickly release heat and become a low-temperature coolant before flowing back into the receiving chamber 15.

[0087] By connecting the power output end 23 and the pump rotor 42 through the connecting shaft 50, the structural complexity of the rotor housing 21 of the rotor assembly 20 can be simplified, which is beneficial to reducing the overall production cost of the external rotor motor.

[0088] Since the power output end 23 of the rotor assembly 20 directly outputs driving force to the power connection end of the pump device 40, the magnitude of the driving force received by the pump device 40 increases or decreases as the mechanical driving force output by the rotor assembly 20 increases. When the mechanical driving force output by the rotor assembly 20 increases, the flow rate of the coolant pumped by the pump device 40 through the receiving chamber 15 is greater (if the cross-sectional area of ​​the flow channel in the receiving chamber 15 is fixed, the flow rate of the coolant is faster), and the cooling capacity of the coolant on the stator assembly 10 is stronger. Conversely, when the mechanical driving force output by the rotor assembly 20 decreases, the flow rate of the coolant pumped by the pump device 40 through the receiving chamber 15 decreases (if the cross-sectional area of ​​the flow channel in the receiving chamber 15 is fixed, the flow rate of the coolant is lower), and the cooling capacity of the coolant on the stator assembly 10 decreases. In other words, the cooling capacity of the coolant for the stator assembly 10 can adapt to changes in the output power of the external rotor motor. The coolant can always meet the cooling requirements of the stator assembly 10, so that the external rotor motor as a whole can always be kept within the normal operating temperature range, and the external rotor motor can always be in the best working performance.

[0089] The coolant is pumped by the pump device 40, enabling it to circulate and flow through the housing chamber 15 to dissipate heat from the coils of the winding 13 and the stator core 12, thus improving the efficiency of coolant cooling. The power output end 23 of the rotor assembly 20 provides driving force to the pump device 40 while simultaneously outputting mechanical driving force, thereby enabling the pump device 40 to start and stop synchronously with the rotor assembly 20.

[0090] In some embodiments, the pump device 40 is a rotary pump. The rotary pump has a small overall volume, which can better fit the narrow and limited hollow cavity 114 of the support frame 11, and is beneficial to the miniaturization and optimization design of the external rotor motor. For example Figure 2 , Figures 14 to 16As shown, the rotary pump includes a pump casing 45, a pump stator 41, and a pump rotor 42. The pump casing 45 is fixedly assembled in the hollow cavity 114 of the support frame 11. The pump stator 41 is fixedly disposed within the pump casing 45 and has a pump chamber 413. The pump casing 45 includes a first pump casing 43 and a second pump casing 44 that are mutually capped and fixed. The pump stator 41 is fixedly disposed within the first pump casing 43, and the first pump casing 43 has an inlet chamber 414 and an outlet chamber 415. Both the inlet chamber 414 and the outlet chamber 415 communicate with the pump chamber 413. The input end 411 and the output end... 412 are all located in the second pump housing 44. The input end 411 is connected to the liquid inlet chamber 414, and the output end 412 is connected to the liquid outlet chamber 415. The input end 411 and the output end 412 are both located in the second pump housing 44, and the input end 411 and the output end 412 are both connected to the pump chamber 413. The pump rotor 42 is the power connection end. The pump rotor 42 is located in the pump chamber 413. The power output end 23 of the rotor assembly 20 drives the pump rotor 42 to rotate synchronously. That is, the power output end 23 of the rotor assembly 20 drives the pump rotor 42 to rotate in the pump chamber 413 to pump coolant. In other words, the magnitude of the driving force received by the pump rotor 42 increases or decreases as the mechanical driving force output by the rotor assembly 20 increases or decreases. When the mechanical driving force output by the rotor assembly 20 increases, the rotational speed of the pump rotor 42 increases, the flow rate of the pumped coolant through the receiving chamber 15 increases, and the cooling capacity of the coolant on the stator assembly 10 becomes stronger. Conversely, when the mechanical driving force output by the rotor assembly 20 decreases, the rotational speed of the pump rotor 42 decreases, the flow rate of the pumped coolant through the receiving chamber 15 decreases, and the cooling capacity of the coolant on the stator assembly 10 decreases. Thus, the cooling capacity of the coolant on the stator assembly 10 can adaptively change with the output power of the external rotor motor, ensuring that the coolant always meets the cooling requirements of the stator assembly 10. This allows the external rotor motor as a whole to always remain within its normal operating temperature range, maintaining optimal performance.

[0091] In some embodiments, the pump assembly 40 may also be a gear pump, or the pump assembly 40 may also be a centrifugal pump. Compared to a rotary pump, a gear pump or a centrifugal pump is less expensive, which helps to reduce the total production cost of the external rotor motor and improve the market competitiveness of the external rotor motor.

[0092] To enable the coolant to circulate and dissipate heat from the stator assembly 10, and to improve the coolant's heat dissipation efficiency, in some embodiments, the external rotor motor further includes a heat dissipation device 60. The heat dissipation device 60 can be directly connected to the support frame 11 or indirectly connected to it. The heat dissipation device 60 dissipates and cools the coolant that has absorbed heat from the stator assembly 10 and flows out of the receiving chamber 15, allowing the coolant to dissipate heat quickly. The cooled coolant can then flow back into the receiving chamber 15 to absorb heat from the stator assembly 10 again, thereby improving the coolant's heat dissipation efficiency. The heat dissipation device 60 has a heat dissipation channel 61, which has an inlet end 62 and an outlet end 63. The inlet end 62 is connected to the output end 412, and the outlet end 63 is connected to the second interface 152. The coolant, having absorbed heat from the stator assembly 10 (i.e., high-temperature coolant), flows from the first interface 151 out of the receiving chamber 15 and through the pump chamber 413. Under the pumping action of the pump device 40, the high-temperature coolant flows to the first inlet end 62 and enters the first heat dissipation channel 61. During its flow through the first heat dissipation channel 61, the high-temperature coolant rapidly releases heat and cools down, causing the coolant flowing to the first outlet end 63 to become low-temperature coolant. Under the pumping action of the pump device 40, the low-temperature coolant flows again from the first outlet end 63 to the second interface 152 and enters the receiving chamber 15 to absorb heat from the stator assembly 10. The coolant circulates in this way, utilizing the heat dissipation device 60 to rapidly dissipate and cool the high-temperature coolant, thereby improving the cooling efficiency of the coolant.

[0093] In the external rotor motor provided in the embodiments of this application, the heat dissipation device 60 can be a water-cooled heat dissipation device, or it can be an air-cooled heat dissipation device. By using air cooling, the heat dissipation device 60 can quickly dissipate and cool down the high-temperature coolant flowing through the first heat dissipation channel 61, thereby improving the heat dissipation and cooling efficiency of the coolant.

[0094] According to a second aspect of the embodiments of this application, an electric drive system is provided. The electric drive system includes a battery, a control module 93 connected to the battery, and an external rotor motor as described above, with windings 13 electrically connected to the control module 93.

[0095] According to a third aspect of the embodiments of this application, an electric vehicle 90 is provided. The electric vehicle 90 includes an external rotor motor as described above; or, the electric vehicle 90 includes an electric drive system as described above.

[0096] The electric vehicle 90 provided in this application embodiment will be illustrated using an electric vehicle as an example. Figure 18As shown, the electric vehicle includes a frame 94, a control module 93, a battery device 92, a drive motor 91, and wheels 95. The control module 93, battery device 92, drive motor 91, and wheels 95 are all mounted on the frame 94. The battery device 92 is electrically connected to the drive motor 91, and the drive motor 91 is driven by the wheels 95. The wheels 95 serve as the electric vehicle's running gear. The drive motor 91 is the aforementioned external rotor motor provided in this embodiment. The battery device 92, control module 93, and external rotor motor combine to form the electric drive system. The battery device 92 can replace the aforementioned battery, supplying power to the drive motor 91, which then drives the wheels 95 to rotate, enabling the electric vehicle to drive normally. Furthermore, the control module 93 is electrically connected to the battery device 92 and is used to control and monitor the charging and discharging status of the battery device 92. The control module 93 is also electrically connected to the windings 13 of the drive motor 91 to control the output power and torque of the drive motor 91. In some electric vehicles, the battery housing of the battery unit 92 can be part of the chassis structure of the electric vehicle. For example, a portion of the battery housing can be at least part of the floor of the electric vehicle, or a portion of the battery housing can be at least part of the crossbeams and longitudinal beams of the electric vehicle.

[0097] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An outer rotor motor comprising a stator assembly and a rotor assembly, the rotor assembly being fitted to the outer circumferential side of the stator assembly, characterized by, The stator assembly includes: The rotor assembly is rotatably mounted on the support frame. Multiple stator cores are fixedly installed on the support frame at circumferential intervals. The extension direction of the stator cores is parallel to the central axis of the external rotor motor. Adjacent stator cores and the support frame form a receiving groove. A winding is wound on the stator core, and at least a portion of the winding is located within the receiving slot; Multiple slot wedges are provided one-to-one in the multiple receiving slots. The extension direction of the slot wedges is parallel to the extension direction of the stator core. Along the circumference of the support frame, the two side edges of the slot wedges are respectively sealed to the side walls of the two adjacent stator cores facing the receiving slots. Furthermore, the radius of the slot wedge from the side surface of the receiving slot to the central axis of the outer rotor motor is less than or equal to the radius of the outer circle of the stator assembly.

2. The external rotor motor according to claim 1, characterized in that, The radius of the slot wedge from the side surface of the receiving slot to the central axis of the external rotor motor is less than or equal to the radius of the stator core from the top wall of the support frame to the central axis of the external rotor motor.

3. The external rotor motor according to claim 1, characterized in that, The stator core has a slot on the side wall facing the receiving groove, and the two side edges of the slot wedge are respectively engaged in the slot.

4. The external rotor motor according to claim 2, characterized in that, The side surface of the slot wedge away from the receiving groove includes two first abutment areas, and the side wall of the stator core facing the receiving groove includes a second abutment area. The two first abutment areas abut against the second abutment areas of two adjacent stator cores, respectively.

5. The external rotor motor according to any one of claims 1-4, characterized in that, The stator assembly further includes at least one end member, which is sleeved on the support frame. The stator assembly has the end member at at least one of its two ends along the central axis of the external rotor motor. The end member, the support frame, the plurality of stator cores, and the plurality of slot wedges together enclose an annular cavity communicating with the plurality of receiving slots.

6. The external rotor motor according to claim 5, characterized in that, The end component includes an end ring. Along the central axis of the external rotor motor, the first end of the end ring is sealed to the end wall of the stator core and the end wall of the slot wedge, and the second end of the end ring is sealed to the support frame to enclose the annular cavity.

7. The external rotor motor according to claim 6, characterized in that, The inner sidewall of the end ring is provided with a plurality of partition plates corresponding one-to-one with the plurality of stator cores. The two ends of the partition plates along the central axis of the outer rotor motor respectively seal against the stator core and the support frame to divide the annular chamber into a plurality of sub-cavities corresponding one-to-one with the plurality of receiving slots.

8. The external rotor motor according to claim 6, characterized in that, The end component further includes a sealing sleeve. The first end of the end ring abuts against the end wall of the stator core and the end wall of the slot wedge. The sealing sleeve is sleeved at the junction of the first end of the end ring and the stator core and the slot wedge to achieve a sealing setting.

9. The external rotor motor according to claim 8, characterized in that, The first end of the end ring is provided with a first clearance step, the end of the stator core is provided with a second clearance step, and the end of the slot wedge is provided with a third clearance step. The first clearance step, the second clearance step, and the third clearance step form an installation groove that is adapted to the sealing sleeve.

10. The external rotor motor according to claim 8, characterized in that, The stator core is provided with support portions at both ends along its extension direction. The support portions extend along the central axis of the external rotor motor. The winding is wound between the support portions and the support frame. The first end of the end ring is inserted into multiple support portions.

11. The external rotor motor according to claim 8, characterized in that, The support frame includes a main frame and an end plate. The main frame includes a cylindrical portion and a radial wall connected to one end of the cylindrical portion. The end plate is fixedly connected to the end of the cylindrical portion away from the radial wall. The stator core is fixedly installed on the cylindrical portion. The second end of one of the end rings is inserted and sealed with the circumferential edge of the radial wall, and the second end of the other end ring is inserted and sealed with the circumferential edge of the end plate.

12. The external rotor motor according to claim 11, characterized in that, The cylindrical portion is integrally formed with the radial wall.

13. The external rotor motor according to claim 11, characterized in that, The stator assembly further includes a first sealing ring, which is disposed between the first end of the end ring and the end wall of the stator core and the end wall of the slot wedge. And / or, the stator assembly further includes a second sealing ring, wherein a second sealing ring is provided between the second end of one of the end rings and the circumferential edge of the radial wall, and a second sealing ring is provided between the second end of the other end ring and the circumferential edge of the end plate.

14. The external rotor motor according to claim 11, characterized in that, The rotor assembly has a power output end, which is rotatably mounted on the end plate. The external rotor motor also includes a pump device and a connecting shaft. The pump device has an input end, an output end, and a power connection end. The support frame has a hollow cavity, and the pump device is installed in the hollow cavity. The connecting shaft is rotatably installed on the support frame. The central axis of the connecting shaft is the same as the central axis of the rotor assembly. The connecting shaft has a first end and a second end. The power output end is driven to the first end, and the second end passes through the end plate and extends into the hollow cavity to be driven to the power connection end. The receiving cavity formed by the annular chamber and the receiving groove has a first interface and a second interface. The input end communicates with the first interface, and the output end communicates with the second interface.

15. The external rotor motor according to claim 14, characterized in that, The pump device is a rotary pump, which includes a pump casing, a pump stator, and a pump rotor. The pump stator is fixedly disposed inside the pump casing and has a pump cavity. The input end and the output end are both disposed in the pump casing and are connected to the pump cavity. The pump rotor is the power connection end and is disposed in the pump cavity. The rotor assembly drives the pump rotor to rotate in the pump cavity to pump coolant.

16. The external rotor motor according to claim 14, characterized in that, The external rotor motor also includes a heat dissipation device, which has a heat dissipation channel with an inlet end and an outlet end. The inlet end is connected to the output end, and the outlet end is connected to the second interface.

17. An electric drive system, characterized by It includes a battery, a control module connected to the battery, and an external rotor motor as described in any one of claims 1-16, wherein the windings are electrically connected to the control module.

18. An electric vehicle, characterized in that, The electric vehicle includes an external rotor motor as described in any one of claims 1-16; or, the electric vehicle includes an electric drive system as described in claim 17.

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