Outer rotor motor

Abstract

This utility model discloses an external rotor motor, which adopts a split insulating frame design in which "a pair of insulating shells seamlessly wrap the upper and lower ends of the stator core respectively". This avoids the different defects of insulating paper, insulating coating and integral insulating frame in terms of processing cost, insulation performance and assembly difficulty. It also exposes the middle part of the stator core and the convex end face, which improves heat dissipation efficiency and magnetic flux utilization. The rotor housing and long magnet are fixed by dovetail slot inserts and adhesives, which makes the assembly precise and stable. It can reduce body vibration and noise and extend the service life of the motor.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to an external rotor motor. Background Technology

[0002] An external rotor motor is an electric motor in which the rotor is located outside the stator. It features low speed and high torque, and is widely used in applications requiring high integration, low noise, and high efficiency, including air conditioning fans, electric vehicle drive systems, industrial compressors, and drone power units. However, existing external rotor motor technologies suffer from traditional technical bottlenecks in areas such as insulation reliability, magnet fixing stability, heat dissipation efficiency, and assembly processes, directly impacting manufacturing costs, assembly efficiency, and performance. Utility Model Content

[0003] In order to overcome the shortcomings of the prior art, this utility model provides an external rotor motor with high insulation reliability, high magnet fixing stability, high heat dissipation efficiency and easy assembly.

[0004] To achieve the above objectives, the technical solution adopted by this utility model to solve its technical problem is: an external rotor motor, comprising:

[0005] The stator assembly includes a stator core, a pair of insulating shells, and several conductor windings. The stator core includes an inner ring block and several circumferentially distributed salient poles extending outward from the side wall of the inner ring block. The salient poles have a T-shaped cross-section, and the end faces of several salient poles are located on the same cylindrical surface. The insulating shells have a semi-enclosed structure and match the shape of the stator core. The pair of insulating shells seamlessly wrap around the upper and lower ends of the stator core, exposing the middle part of the stator core and the end faces of several salient poles. Several conductor windings are wound around the pair of insulating shells to wrap around each salient pole.

[0006] The rotor assembly includes a rotor housing and several long magnets. The inner wall of the rotor housing has several magnet mounting slots with narrow openings and wide bottoms, and a dovetail-shaped cross-section. The long magnets and the magnet mounting slots correspond one-to-one, match in shape, and are inserted and limited. An adhesive is also added between the long magnets and the magnet mounting slots. The end face of the long magnets is higher than the opening of the magnet mounting slot.

[0007] In some embodiments, the number of salient poles is 18 and the number of long strip magnets is 20.

[0008] In some embodiments, the rotor housing includes an end cover body and an inner ring plate. The inner ring plate is countersunk in the opening of the end cover body. The inner ring plate and the end cover body are connected by a keyway and fixed by an interference fit. A plurality of magnet mounting slots are formed on the inner wall of the inner ring plate.

[0009] In some embodiments, the end face of the end cap body is hollowed out to form a stationary leaf.

[0010] In some embodiments, the device further includes a housing and a motor shaft. The housing completely encloses and seals the stator assembly and the rotor assembly. The housing includes an end cover and a bottom cover. The end cover has a shaft extension hole extending from the upper end of the motor shaft at the center of its end face. An oil seal is provided in the shaft extension hole. The motor shaft passes through the stator assembly at the center and is fixedly connected to the rotor assembly at the lower end.

[0011] In some embodiments, the end cover extends downward from the shaft extension hole to form a sleeve-shaped support portion, which is fixedly connected to the stator assembly.

[0012] In some embodiments, the end cover of the whole machine is integrally formed, and a number of reinforcing ribs are connected to the inner wall between its end face and the support part.

[0013] In some embodiments, a plurality of vertically protruding heat dissipation ribs are evenly distributed circumferentially on the side wall of the end cover of the machine. The lower end of the heat dissipation ribs is higher than the opening of the end cover of the machine. The opening of the end cover of the machine fits into the opening of the bottom cover. The lower ends of the plurality of heat dissipation ribs abut against the opening of the bottom cover.

[0014] Due to the application of the above technical solution, this utility model has the following beneficial effects compared with the prior art:

[0015] This utility model adopts a split insulating frame design in which "a pair of insulating shells seamlessly wrap the upper and lower ends of the stator core respectively". This avoids the different defects of insulating paper, insulating coating and integral insulating frame in terms of processing cost, insulation performance and assembly difficulty. It also exposes the middle part of the stator core and the convex end face, which improves heat dissipation efficiency and magnetic flux utilization. The rotor housing and long magnet are fixed by dovetail slot inserts and adhesives, which makes the assembly precise and stable. It can reduce machine vibration and noise and extend the service life of the motor. Attached Figure Description

[0016] Figure 1 This is a perspective view of one embodiment of the external rotor motor proposed in this utility model.

[0017] Figure 2 This is an explosion of Embodiment 1 of the external rotor motor proposed in this utility model. Figure 1 .

[0018] Figure 3 This is an explosion of Embodiment 1 of the external rotor motor proposed in this utility model. Figure 2 .

[0019] Figure 4 This is an exploded view of the stator assembly in Embodiment 1 of the external rotor motor proposed in this utility model.

[0020] Figure 5 yes Figure 2 Enlarged view of part A in the middle.

[0021] In the diagram: 1. Stator core; 2. Insulating shell; 3. Inner ring block; 4. Salient pole; 5. Rotor housing; 6. Long magnet; 7. Magnet mounting slot; 8. End cover body; 9. Inner ring plate; 10. Stationary vane; 11. Complete housing; 12. Motor shaft; 13. Complete end cover; 14. Bottom cover; 15. Shaft extension hole; 16. Oil seal; 17. Support section; 18. Reinforcing rib; 19. Heat dissipation rib; 20. Upper bearing; 21. Lower bearing; 22. Lead-out hole; 23. Wire groove; 24. Sealing ring. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to specific embodiments:

[0023] Figures 1 to 5 This invention discloses one embodiment of the external rotor motor proposed in this utility model.

[0024] Combination Figure 1 , Figure 2 and Figure 3 Embodiment 1 includes a housing 11, a motor shaft 12, an oil seal 16, an upper bearing 20, a stator assembly, a lower bearing 21, and a rotor assembly, wherein:

[0025] The housing 11 completely encloses and seals the stator and rotor assemblies. The housing 11 includes an end cover 13 and a bottom cover 14. The end cover 13 has a shaft extension hole 15 extending from the upper end of the motor shaft 12 at its center. An oil seal 16 is disposed within the shaft extension hole 15. The motor shaft 12 passes through the upper bearing 20 and the stator assembly but is not circumferentially connected. Its lower end is fixedly connected to the rotor assembly via a lower bearing 21. The end cover 13 extends downwards from the shaft extension hole 15 to form a sleeve-shaped support portion 17, which is fixedly connected to the stator assembly. 3. The end cover 13 is integrally molded, and several reinforcing ribs 18 are connected to the inner wall between the end face and the support part 17. Several vertically protruding heat dissipation ribs 19 are evenly distributed on the side wall of the end cover 13. The lower end of the heat dissipation ribs 19 is higher than the opening of the end cover 13. The opening of the end cover 13 fits into the opening of the bottom cover 14. The lower ends of several heat dissipation ribs 19 all abut against the opening of the bottom cover 14. In addition, an electrical wire (not shown) lead-out hole 22 is provided at the connection between the end cover 13 and the bottom cover 14. A wire groove 23 and a sealing ring 24 are provided on the inner side. After the lead wire is assembled at the lead-out hole 22, it is sealed with glue.

[0026] Combined Figure 4The stator assembly includes a stator core 1, a pair of insulating shells 2, and several conductor windings (not shown). The stator core 1 includes an inner ring block 3 and several circumferentially distributed salient poles 4 extending outward from the side wall of the inner ring block 3. The cross-section of the salient pole 4 is T-shaped, and the end faces of several salient poles 4 are located on the same cylindrical surface. The insulating shell 2 is a semi-enclosed structure and matches the shape of the stator core 1. The pair of insulating shells 2 seamlessly wrap the upper and lower ends of the stator core 1, exposing the middle part of the stator core 1 and the end faces of several salient poles 4. Several conductor windings are wound on the pair of insulating shells 2 to wrap around each salient pole 4.

[0027] Combined Figure 5 The rotor assembly includes a rotor housing 5 and several long magnets 6. The rotor housing 5 includes an end cover body 8 and an inner ring plate 9. The inner ring plate 9 is countersunk in the opening of the end cover body 8. The inner ring plate 9 and the end cover body 8 are connected by a keyway and fixed by an interference fit. Several magnet mounting slots 7 with narrow openings and wide bottoms and dovetail-shaped cross sections are evenly distributed on the inner wall of the inner ring plate 9. The several long magnets 6 and the several magnet mounting slots 7 correspond one-to-one, match in shape and are inserted and limited. An adhesive (not shown) is also added between the long magnets 6 and the magnet mounting slots 7. The end face of the long magnet 6 is higher than the opening of the magnet mounting slot 7. The end face of the end cover body 8 is hollowed out to form a stationary blade 10.

[0028] In this embodiment:

[0029] The number of salient poles 4 is 18, and the number of long bar magnets 6 is 20, that is, this embodiment is an 18-pole 20-slot external rotor motor;

[0030] The insulation device of the stator core 1 adopts a split insulation skeleton design. A pair of insulation shells 2 seamlessly wrap the upper and lower ends of the stator core 1. The insulation shells 2 wrap the salient poles 4 to form several winding grooves 23 with limiting structures. This avoids the different defects of insulation paper, insulation coating and integral insulation skeleton in terms of processing cost, insulation performance and assembly difficulty. The upper and lower ends of the stator core 1 are quickly positioned and assembled by inserting the insulation shells 2. It is suitable for rapid pressing on the automated production line and precise positioning and winding of automated winding equipment. In addition, the insulation shells 2 can also integrate wire outlet holes or wire binding posts to fix the lead wires of the conductor winding, reduce the insulation wrapping process of the lead wire bundle and lead wire. The end face of the salient pole 4 is completely exposed and fully participates in the air gap magnetic circuit, reduces the obstruction of the magnetic field by the insulation material, improves the magnetic flux utilization rate, and thus improves the motor efficiency.

[0031] The long strip magnet 6 and the magnet mounting slot 7 are inserted and fixed to form a mechanical lock and reinforced with adhesive. This facilitates quick positioning and pushing in during tooling or manual installation. The positioning is accurate, and even if the adhesive ages, it can maintain high strength fixation, ensuring that the long strip magnet 6 is always evenly distributed in the circumference, improving the symmetry of the air gap magnetic field, reducing electromagnetic vibration and noise, and extending the service life of the motor. The rotor housing 5 is composed of the end cover body 8 and the inner ring plate 9. The inner ring plate 9 is processed separately to make the magnet mounting slot 7 precisely formed, and then quickly positioned, inserted and pressed in, reducing processing difficulty and waste.

[0032] The end cover 13 and bottom cover 14 fit tightly to completely enclose the stator assembly and rotor assembly and form a seal, resulting in good motor protection performance and a high protection level. There are gaps between the stator assembly and rotor assembly, and between the two assemblies and the whole machine housing 11. The end face of the end cover body 8 is hollowed out to form the stator blade 10, so a complete airflow circulation path is formed inside the whole machine housing 11. The airflow evenly conducts the heat of each component to the surface of the whole machine housing 11 for heat dissipation. Heat dissipation fins 19 are also provided on the end cover 13 to promote heat dissipation. Among them, the pair of semi-enclosed insulating shells 2 only enclose the upper and lower ends of the stator core 1, leaving the middle part exposed. The heat of the upper part of the stator core 1 is directly conducted from its middle to the external airflow, resulting in high heat dissipation efficiency.

[0033] The above embodiments are only for illustrating the technical concept and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it. They should not be used to limit the protection scope of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the protection scope of this utility model.

Claims

1. An external rotor electric machine, characterized by, include: The stator assembly includes a stator core (1), a pair of insulating shells (2) and several conductor windings. The stator core (1) includes an inner ring block (3) and several circumferentially distributed salient poles (4) extending outward from the side wall of the inner ring block (3). The salient poles (4) have a T-shaped cross section. The end faces of several salient poles (4) are located on the same cylindrical surface. The insulating shells (2) are semi-enclosed structures and match the shape of the stator core (1). The pair of insulating shells (2) seamlessly wrap the upper and lower ends of the stator core (1), exposing the middle part of the stator core (1) and the end faces of several salient poles (4) are completely exposed. Several conductor windings are wound around the pair of insulating shells (2) to wrap around each of the salient poles (4). The rotor assembly includes a rotor housing (5) and several long magnets (6). The inner wall of the rotor housing (5) is evenly distributed with several magnet mounting slots (7) that are narrow at the opening and wide at the bottom and have a dovetail-shaped cross section. The several long magnets (6) and the several magnet mounting slots (7) correspond to each other, match in shape and are inserted and limited. An adhesive is also added between the long magnets (6) and the magnet mounting slots (7). The end face of the long magnets (6) is higher than the opening of the magnet mounting slots (7).

2. An external rotor electric machine according to claim 1, characterized in that: The number of salient poles (4) is 18, and the number of long strip magnets (6) is 20.

3. An external rotor electric machine according to claim 1, characterized in that: The rotor housing (5) includes an end cover body (8) and an inner ring plate (9). The inner ring plate (9) is countersunk in the opening of the end cover body (8). The inner ring plate (9) and the end cover body (8) are connected by a keyway and fixed by an interference fit. A plurality of magnet mounting slots (7) are opened on the inner wall of the inner ring plate (9).

4. An external rotor electric machine according to claim 3, characterized in that: The end cap body (8) has a hollowed-out end face to form a stationary leaf (10).

5. The external rotor electric machine of claim 1, wherein: It also includes a complete housing (11) and a motor shaft (12). The complete housing (11) completely encloses and seals the stator assembly and the rotor assembly. The complete housing (11) includes a complete end cover (13) and a bottom cover (14). The end cover (13) has a shaft extension hole (15) in the middle of its end face for the upper end of the motor shaft (12) to extend out. An oil seal (16) is provided in the shaft extension hole (15). The middle part of the motor shaft (12) passes through the stator assembly and the lower end is fixedly connected to the rotor assembly.

6. An external rotor electric machine according to claim 5, characterized in that: The end cover (13) of the whole machine extends downward from the shaft extension hole (15) to form a sleeve-shaped support part (17), and the support part (17) is fixedly connected to the stator assembly.

7. An external rotor electric motor as claimed in claim 6, characterised in that: The end cap (13) of the whole machine is integrally formed, and a number of reinforcing ribs (18) are connected to the inner wall between its end face and the bracket part (17).

8. The external rotor motor according to claim 5, characterized in that: The side wall of the end cover (13) of the machine is evenly distributed with several vertically protruding heat dissipation ribs (19). The lower end of the heat dissipation ribs (19) is higher than the opening of the end cover (13). The opening of the end cover (13) of the machine fits into the opening of the bottom cover (14). The lower ends of several heat dissipation ribs (19) all abut against the opening of the bottom cover (14).

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