Water-cooling structure and outer rotor permanent magnet motor

Abstract

The utility model provides a kind of water cooling structure and outer rotor permanent magnet motor, belong to the technical field of motor, wherein outer rotor permanent magnet motor includes outer rotor structure, inner stator structure and two end covers;Water cooling structure includes cooling water channel and inlet and outlet water component;Cooling water channel is arranged in the inside of annular plate in inner stator structure;Inlet and outlet water component is arranged on inner stator structure, and is used to supply and discharge coolant to cooling water channel in circulation;Cooling water channel includes multiple direct current sections and multiple bending sections;Multiple direct current sections circumferential interval distribution in the inside of annular plate in inner stator structure, and the extension direction of direct current section is parallel to the axial direction of inner stator structure;Multiple bending sections are communicated between the end of adjacent two direct current sections, and close to the both ends of annular plate.The utility model passes through the combination of direct current section and bending section, makes coolant constantly flow through the both ends of annular plate, avoids temperature gradient to be generated at the both ends of inner stator structure, improves heat dissipation effect.

Description

Technical Field

[0001] This utility model belongs to the technical field of electric motors, and more specifically, it relates to a water-cooled structure and an external rotor permanent magnet motor. Background Technology

[0002] An external rotor permanent magnet motor is a type of permanent magnet synchronous motor in which the rotor is located outside the stator. It is commonly used in industrial motor applications such as hoists and belt conveyors.

[0003] The external rotor permanent magnet motor includes an external rotor structure, an inner stator structure, and two end covers. The external rotor structure includes a drum body and permanent magnets disposed on the inner circumferential surface of the drum body. The inner stator structure is located inside the external rotor structure and includes a shaft, a stator support, a stator core, and a stator winding. The stator support includes a frame and an annular plate. The frame is fixed between the shaft and the annular plate. The stator core and the stator winding are mounted on the outer circumferential surface of the annular plate. The end covers are fastened to both ends of the drum body.

[0004] To extend the lifespan of motors, cooling structures are typically incorporated. Current water-cooling systems for motors involve creating spiral channels within an annular plate of the stator support. These channels spiral around the annular plate from one end to the other, with coolant supplied to the spiral channels via external water passages to cool the inner stator structure. However, because the coolant travels a long distance and takes a considerable amount of time to flow from one end of the annular plate to the other, a temperature gradient develops between the two ends of the inner stator structure, resulting in poor heat dissipation. Utility Model Content

[0005] The purpose of this invention is to provide a water-cooled structure and an external rotor permanent magnet motor to solve the technical problem in the prior art where the coolant in the spiral water channel has a long path and time to flow from one end of the annular plate to the other, resulting in a temperature gradient at both ends of the inner stator structure and poor heat dissipation.

[0006] To achieve the above objectives, in the first aspect, the technical solution adopted by this utility model is: to provide a water-cooling structure for installation on an external rotor permanent magnet motor, wherein the external rotor permanent magnet motor includes an external rotor structure, an inner stator structure and two end covers; the water-cooling structure includes cooling water channels and inlet / outlet water assemblies;

[0007] The cooling water channel includes multiple direct-flow sections and multiple bend sections. The multiple direct-flow sections are circumferentially spaced inside the annular plate in the inner stator structure. The extension direction of the direct-flow sections is parallel to the axial direction of the inner stator structure, and the ends of the direct-flow sections are close to the ends of the annular plate. The ends of each pair of adjacent direct-flow sections are connected by a bend section.

[0008] The inlet and outlet water assembly is disposed on the inner stator structure and is used to circulate and supply coolant to and discharge the cooling water channel.

[0009] In conjunction with the first aspect, in one possible implementation, the cooling water channel further includes:

[0010] An arc-shaped flow guide section is located at one end within the annular plate of the inner stator structure;

[0011] The water outlet of the water inlet / outlet assembly is connected to one of the DC sections, the water inlet of the water inlet / outlet assembly is connected to one end of the arc-shaped guide section, the other end of the arc-shaped guide section is connected to another DC section, and this DC section is adjacent to the water outlet of the water inlet / outlet assembly.

[0012] In conjunction with the first aspect, in one possible implementation, the annular plate is axially divided into an inner cover and an outer cover along the outer circumferential surface of the cooling water channel, and the outer cover is detachably fixed to the inner cover.

[0013] In conjunction with the first aspect, in one possible implementation, the inlet / outlet water assembly includes:

[0014] A water inlet / outlet seat, fixed to a shaft within the inner stator structure, has one end located outside the end cover and used to connect to an external circulating cooling system, while the other end is located inside the end cover; and

[0015] Two inlet and outlet pipes are located inside the end cap and connected between the inner end of the inlet and outlet water seat and the cooling water channel;

[0016] The inlet and outlet water seat has two flow channels connecting its inner and outer ends, and the flow channels are connected to the inlet and outlet pipes one by one.

[0017] In conjunction with the first aspect, in one possible implementation, the inlet / outlet water seat includes:

[0018] Inner seat sleeve, coaxially sleeved on the shaft in the inner stator structure; and

[0019] The outer seat sleeve is coaxially sleeved on the inner seat sleeve and detachably connected to the outer seat sleeve;

[0020] The flow channel is formed on the outer circumferential surface of the inner seat sleeve, and the inlet and outlet pipes are connected to the corresponding flow channel through the outer seat sleeve.

[0021] In conjunction with the first aspect, in one possible implementation, the inlet and outlet conduits include:

[0022] Multiple straight pipes, perpendicular or parallel to the axis of the inlet / outlet water base, wherein the ends of two of the straight pipes are detachably connected to the inlet / outlet water base and the annular plate, respectively; and

[0023] Multiple bends, each bend being connected between two adjacent straight pipes;

[0024] The two adjacent straight pipes are perpendicular to each other.

[0025] In conjunction with the first aspect, in one possible implementation, the straight pipe is connected to the inlet / outlet water seat, and the straight pipe is connected to the annular plate via flanges.

[0026] In conjunction with the first aspect, in one possible implementation, the two flow channels are arranged symmetrically about the axis of the inlet and outlet water seats.

[0027] In conjunction with the first aspect, in one possible implementation, a bearing is provided between each of the end caps and the shaft in the inner stator structure, with one of the bearings located between the end cap and the inlet / outlet water seat.

[0028] Secondly, this utility model also provides an external rotor permanent magnet motor, including the above-mentioned water-cooling structure.

[0029] The beneficial effects of the water-cooling structure provided by this utility model are as follows: Compared with the prior art, this utility model realizes the cooling liquid circulation of the cooling water channel through the inlet and outlet water components. By combining the direct flow section and the bending section, the contact area between the coolant and the annular plate can be maximized. Each direct flow section and the bending section is interconnected to form a complete cooling circuit, which allows the coolant to circulate smoothly in the entire water channel and avoids the existence of cooling dead zones. The coolant continuously flows through both ends of the annular plate, avoiding the generation of temperature gradients at both ends of the inner stator structure and improving the heat dissipation effect. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model, 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 these drawings without creative effort.

[0031] Figure 1 A vertical sectional view of a water-cooled structure and an external rotor permanent magnet motor provided in an embodiment of the present invention;

[0032] Figure 2 Vertical sectional view of the stator support and cooling water channel provided in the embodiment of the present invention. Figure 1 ;

[0033] Figure 3 Vertical sectional view of the stator support and cooling water channel provided in the embodiment of the present invention. Figure 2 ;

[0034] Figure 4 A plan view of the cooling water channel provided in an embodiment of the present invention;

[0035] Figure 5 A vertical sectional view of the water inlet / outlet assembly provided in an embodiment of the present invention;

[0036] Figure 6 Vertical cross-sectional view of the inlet / outlet water seat provided in an embodiment of the present invention. Figure 1 ;

[0037] Figure 7 Vertical cross-sectional view of the inlet / outlet water seat provided in an embodiment of the present invention. Figure 2 .

[0038] The labels for the attached figures are as follows:

[0039] 1. External rotor structure; 11. Drum body; 12. Permanent magnet;

[0040] 2. Inner stator structure; 21. Shaft; 22. Stator support; 221. Frame; 222. Annular plate; 2221. Inner cover; 2222. Outer cover; 23. Stator core; 24. Stator winding;

[0041] 3. End cap; 31. Bearing;

[0042] 4. Cooling water channel; 41. Straight flow section; 42. Bend section; 43. Arc-shaped guide section;

[0043] 5. Inlet / outlet water assembly; 51. Inlet / outlet water seat; 511. Inner seat sleeve; 5111. Flow channel; 512. Outer seat sleeve; 52. Inlet / outlet pipe; 521. Straight pipe; 522. Bend. Detailed Implementation

[0044] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the described embodiments are only a part of the embodiments of this application, not all of them. The specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] It should be further noted that the accompanying drawings and embodiments of this utility model mainly describe the concept of this utility model. Based on this concept, some specific forms and settings of connection relationships, positional relationships, power mechanisms, power supply systems and control systems may not be fully described. However, under the premise that those skilled in the art understand the concept of this utility model, they can implement the above-mentioned specific forms and settings in a well-known manner.

[0046] When a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0047] The present invention will now describe a water-cooled structure and an external rotor permanent magnet motor.

[0048] like Figure 1 and Figure 2 As shown, the first embodiment of this utility model provides a water-cooled structure for installation on an external rotor permanent magnet motor. The external rotor permanent magnet motor includes an external rotor structure 1, an inner stator structure 2, and two end covers 3. The external rotor structure 1 includes a roller body 11 and permanent magnets 12 disposed on the inner circumferential surface of the roller body 11. The inner stator structure 2 is located inside the external rotor structure 1 and includes a shaft body 21, a stator support 22, a stator core 23, and a stator winding 24. The stator support 22 includes a frame body 221 and an annular plate 222. The frame body 221 is fixed between the shaft body 21 and the annular plate 222. The stator core 23 and the stator winding 24 are installed on the outer circumferential surface of the annular plate 222. The end covers 3 are fastened to both ends of the roller body 11.

[0049] The water-cooled structure includes a cooling water channel 4 and an inlet / outlet water assembly 5; the cooling water channel 4 is located inside the annular plate 222 in the inner stator structure 2; the inlet / outlet water assembly 5 is located on the inner stator structure 2 and is used to circulate and supply coolant to and discharge coolant from the cooling water channel 4.

[0050] like Figures 2 to 4 As shown, the cooling water channel 4 includes multiple direct flow sections 41 and multiple bend sections 42; the multiple direct flow sections 41 are circumferentially spaced inside the annular plate 222 in the inner stator structure 2, and the extension direction of the direct flow sections 41 is parallel to the axial direction of the inner stator structure 2; the bend sections 42 are close to both ends of the annular plate 222, and the ends of each two adjacent direct flow sections 41 are connected by one bend section 42.

[0051] The water-cooling structure provided in this embodiment, compared with the prior art, realizes the coolant circulation of the cooling water channel 4 through the inlet and outlet water components 5. By combining the direct flow section 41 and the bending section 42, the contact area between the coolant and the annular plate 222 can be maximized. Each direct flow section 41 and the bending section 42 is interconnected to form a complete S-shaped cooling circuit, which allows the coolant to circulate smoothly in the entire water channel and avoids the existence of cooling dead zones. The coolant continuously flows through both ends of the annular plate 222, avoiding the generation of temperature gradients at both ends of the inner stator structure 2 and improving the heat dissipation effect.

[0052] like Figure 4 As shown, based on the first embodiment, this utility model provides another specific embodiment as follows:

[0053] The cooling water channel 4 also includes an arc-shaped guide section 43, which is located at one end of the annular plate 222 in the inner stator structure 2;

[0054] The outlet of the water inlet and outlet component 5 is connected to one of the direct current sections 41, the inlet of the water inlet and outlet component 5 is connected to one end of the arc-shaped guide section 43, the other end of the arc-shaped guide section 43 is connected to another direct current section 41, and this direct current section 41 is adjacent to the outlet of the water inlet and outlet component 5.

[0055] The inlet / outlet water assembly 5 injects coolant into the arc-shaped guide section 43. Its smooth arc structure can effectively reduce the resistance of the coolant during the flow process, allowing the coolant to smoothly transition from one direct flow section 41 to another. This enables the coolant to flow through the direct flow section 41 between the inlet and outlet in the cooling water channel 4, ensuring that each direct flow section 41 and bend section 42 can be fully traversed by the coolant, thus achieving full utilization of the cooling water channel 4.

[0056] like Figure 2 and Figure 3 As shown, based on the first embodiment, this utility model provides another specific embodiment as follows:

[0057] The annular plate 222 is axially divided into an inner cover 2221 and an outer cover 2222 along the outer circumferential surface of the cooling water channel 4. The outer cover 2222 is detachably fixed to the inner cover 2221.

[0058] Specifically, in this embodiment, the inner cover 2221 and the outer cover 2222 can be connected by heat fitting or bolts.

[0059] During processing, the water channels on the inner casing 2221 and the outer casing 2222 can be machined separately, simplifying the processing difficulty of complex water channels and reducing manufacturing process requirements and production costs. During installation, it is easier to clean and inspect the cooling water channels 4, ensuring that the inside of the channels is free of impurities and blockages. When the cooling water channels 4 experience blockages, leaks, or other malfunctions, repair or replacement can be performed simply by disassembling the outer casing 2222.

[0060] like Figure 5 and Figure 6 As shown, based on the first embodiment, this utility model provides another specific embodiment as follows:

[0061] The inlet and outlet water assembly 5 includes an inlet and outlet water seat 51 and two inlet and outlet pipes 52. The inlet and outlet water seat 51 is fixed on the shaft 21 in the inner stator structure 2. One end of the inlet and outlet water seat 51 is located outside the end cover 3 and is used to connect to the external circulating cooling system. The other end of the inlet and outlet water seat 51 is located inside the end cover 3. The two inlet and outlet pipes 52 are located inside the end cover 3 and are connected between the inner end of the inlet and outlet water seat 51 and the cooling water channel 4.

[0062] The inlet / outlet water base 51 has two flow channels 5111 connecting its inner and outer ends, and the flow channels 5111 are connected to the inlet / outlet pipes 52 in a one-to-one correspondence. The external circulating cooling system connected to the outer end of the inlet / outlet water base 51 can be a heat exchanger or a cooling tower.

[0063] It should be noted that of the two inlet and outlet pipes 52, one is the inlet pipe and the other is the outlet pipe. External coolant enters one of the flow channels 5111 in the inlet / outlet water seat 51, and then enters the cooling water channel 4 through the inlet / outlet pipe 52. The coolant at the outlet of the cooling water channel 4 then flows through the other inlet / outlet pipe 52 to the other flow channel 5111 of the inlet / outlet water seat 51 for discharge. This allows the inlet and outlet to proceed independently without interference, ensuring unidirectional circulation of the coolant, avoiding the mixing of hot and cold coolant, and improving heat exchange efficiency.

[0064] Furthermore, the design of the inlet and outlet water seat 51 eliminates the need to drill holes in the shaft 21 to allow the inlet and outlet pipes 52 to enter the motor, thus ensuring the strength of the shaft 21 itself.

[0065] like Figure 6 As shown, based on the first embodiment, this utility model provides another specific embodiment as follows:

[0066] The inlet / outlet water seat 51 includes an inner seat sleeve 511 and an outer seat sleeve 512. The inner seat sleeve 511 is coaxially sleeved on the shaft 21 in the inner stator structure 2; the outer seat sleeve 512 is coaxially sleeved on the inner seat sleeve 511 and is detachably connected to the outer seat sleeve 512.

[0067] The flow channel 5111 is located on the outer circumferential surface of the inner sleeve 511, and the inlet and outlet pipes 52 are connected to the corresponding flow channel 5111 through the outer sleeve 512.

[0068] Specifically, in this embodiment, the inner sleeve 511 and the outer sleeve 512 can be connected by heat fitting or bolts.

[0069] The inner sleeve 511 and the outer sleeve 512 can be machined separately, reducing the difficulty of machining. During assembly, only the inner sleeve 511 and the outer sleeve 512 need to be fitted and connected. When the flow channel 5111 of the inlet and outlet water seat 51 becomes blocked or damaged, since the inner sleeve 511 and the outer sleeve 512 are detachably connected, the inner sleeve 511 can be easily removed from the outer sleeve 512 for cleaning or replacement, without the need to replace the entire inlet and outlet water seat 51, thus reducing maintenance costs and difficulty.

[0070] like Figure 5 As shown, based on the first embodiment, this utility model provides another specific embodiment as follows:

[0071] The inlet and outlet pipes 52 include multiple straight pipes 521 and multiple bends 522. The multiple straight pipes 521 are perpendicular or parallel to the axis of the inlet and outlet water seat 51. The ends of two straight pipes 521 are detachably connected to the inlet and outlet water seat 51 and the annular plate 222, respectively. Each bend 522 is connected between two adjacent straight pipes 521. The two adjacent straight pipes 521 are perpendicular to each other.

[0072] In some possible embodiments, the straight tube 521 and the bent tube 522 may be selected according to different motor sizes and differences in assembly.

[0073] The inlet and outlet pipes 52 can be flexibly arranged according to the internal space layout of the external rotor permanent magnet motor, avoiding the installation difficulties caused by the limited internal space of the motor. The design of the adjacent straight pipes 521 being perpendicular to each other makes the flow of coolant in the inlet and outlet pipes 52 smoother, reducing flow resistance and turbulence.

[0074] like Figure 5 As shown, based on the first embodiment, this utility model provides another specific embodiment as follows:

[0075] The straight pipe 521 is connected to the inlet / outlet water seat 51 and the straight pipe 521 is connected to the annular plate 222 by flanges.

[0076] Flange connections offer excellent sealing, effectively preventing coolant leakage at the connection points and ensuring the normal operation of the water-cooled structure. They also facilitate subsequent disassembly and maintenance.

[0077] like Figure 7As shown, based on the first embodiment, this utility model provides another specific embodiment as follows:

[0078] The two flow channels 5111 are symmetrically arranged along the axis of the inlet and outlet water seats 51.

[0079] The symmetrical flow channel 5111 design helps to optimize the distribution of coolant in the cooling channel 4, allowing the coolant to flow more rationally in multiple direct flow sections 41 and bend sections 42, and fully utilize the heat dissipation function of the cooling channel 4.

[0080] like Figure 1 As shown, based on the first embodiment, this utility model provides another specific embodiment as follows:

[0081] Each end cap 3 is provided with a bearing 31 between the shaft 21 in the inner stator structure 2 and the shaft 21, with one bearing 31 located between the end cap 3 and the inlet / outlet water seat 51.

[0082] The bearing 31 ensures smooth relative rotation between the end cover 3 and the shaft 21, reduces frictional loss, and improves the mechanical efficiency and operational stability of the motor. Furthermore, the circulating coolant within the inlet and outlet water seats 51 effectively cools the bearing 31.

[0083] like Figure 1 As shown, based on the same inventive concept, the second embodiment of the present invention provides an external rotor permanent magnet motor, including the above-mentioned water-cooling structure.

[0084] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

[0085] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0086] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

Claims

1. A water-cooled structure for mounting on an external rotor permanent magnet motor, the external rotor permanent magnet motor comprising an external rotor structure (1), an inner stator structure (2), and two end caps (3); characterized in that, The water-cooling structure includes a cooling water channel (4) and an inlet / outlet water assembly (5); The cooling water channel (4) includes multiple direct-flow sections (41) and multiple bend sections (42). The multiple direct-flow sections (41) are circumferentially spaced inside the annular plate (222) in the inner stator structure (2). The extension direction of the direct-flow sections (41) is parallel to the axial direction of the inner stator structure (2), and the ends of the direct-flow sections (41) are close to the ends of the annular plate (222). The ends of each pair of adjacent direct-flow sections (41) are connected by a bend section (42). The inlet and outlet water assembly (5) is disposed on the inner stator structure (2) and is used to circulate and supply and discharge coolant to the cooling water channel (4).

2. The water-cooling structure as described in claim 1, characterized in that, The cooling water channel (4) also includes: The arc-shaped guide section (43) is located at one end within the annular plate (222) in the inner stator structure (2); The outlet of the water inlet / outlet assembly (5) is connected to one of the direct current sections (41), the inlet of the water inlet / outlet assembly (5) is connected to one end of the arc-shaped guide section (43), the other end of the arc-shaped guide section (43) is connected to another direct current section (41), and this direct current section (41) is adjacent to the outlet of the water inlet / outlet assembly (5).

3. The water-cooling structure as described in claim 1, characterized in that, The annular plate (222) is axially divided into an inner cover (2221) and an outer cover (2222) along the outer circumferential surface of the cooling water channel (4). The outer cover (2222) is detachably fixed to the inner cover (2221).

4. The water-cooling structure as described in claim 1, characterized in that, The inlet and outlet water assembly (5) includes: A water inlet / outlet seat (51) is fixed on a shaft (21) in the inner stator structure (2). One end of the water inlet / outlet seat (51) is located outside the end cover (3) and is used to connect to an external circulating cooling system. The other end of the water inlet / outlet seat (51) is located inside the end cover (3). Two inlet and outlet pipes (52) are located inside the end cap (3) and connected between the inner end of the inlet and outlet water seat (51) and the cooling water channel (4); The inlet / outlet water seat (51) has two flow channels (5111) that connect its inner and outer ends, and the flow channels (5111) are connected to the inlet / outlet pipes (52) one by one.

5. A water-cooling structure as described in claim 4, characterized in that, The inlet / outlet water seat (51) includes: Inner seat sleeve (511), coaxially sleeved on the shaft (21) in the inner stator structure (2); and The outer seat sleeve (512) is coaxially sleeved on the inner seat sleeve (511) and is detachably connected to the outer seat sleeve (512); The flow channel (5111) is formed on the outer circumferential surface of the inner sleeve (511), and the inlet / outlet pipe (52) is connected to the corresponding flow channel (5111) through the outer sleeve (512).

6. A water-cooling structure as described in claim 4, characterized in that, The inlet and outlet pipes (52) include: Multiple straight pipes (521) are perpendicular or parallel to the axis of the inlet / outlet water seat (51), wherein the ends of two of the straight pipes (521) are detachably connected to the inlet / outlet water seat (51) and the annular plate (222), respectively; and Multiple bends (522), each bend (522) being connected between two adjacent straight pipes (521); The two adjacent straight pipes (521) are perpendicular to each other.

7. A water-cooled structure as described in claim 6, characterized in that, The straight pipe (521) and the inlet / outlet water seat (51) are connected by flanges, as are the straight pipe (521) and the annular plate (222).

8. A water-cooled structure as described in claim 4, characterized in that, The two flow channels (5111) are symmetrically arranged along the axis of the inlet and outlet water seats (51).

9. A water-cooled structure as described in claim 4, characterized in that, Each of the end caps (3) is provided with a bearing (31) between it and the shaft (21) in the inner stator structure (2), and one of the bearings (31) is located between the end cap (3) and the inlet / outlet water seat (51).

10. An external rotor permanent magnet motor, characterized in that, Includes the water-cooled structure as described in any one of claims 1-9.

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