A mid-mounted motor

Abstract

The present invention relates to a mid-mounted motor, comprising a rotor and a stator mounted on the rotor, and a stator housing with a hollow interior. The stator and rotor are both located within the stator housing. The rotor is provided with a motor shaft hole, a motor shaft is passed through the motor shaft hole, and an input gear is provided on the motor shaft. A front cover and a rear cover are mounted on each end of the stator housing. A second motor shaft cavity is formed on a side of the front cover proximate to the stator housing, and a first gear cavity is formed on the other side of the front cover. Compared with the prior art, the present invention utilizes an integrally formed motor shaft and input gear, replacing a spline connection between the two, resulting in higher transmission efficiency and lower noise. Furthermore, by directly forming a gear cavity on the front cover, replacing the need for a gear box mounted on the front cover, the present invention achieves improved waterproofing, simple assembly, a simple structure, and small space requirements.

Description

Technical Field

[0001] The invention relates to a mid-mounted motor and belongs to the technical field of electric vehicles. Background Art

[0002] Current electric vehicle motor installation methods primarily include mid-mount, hub-mount, and side-mount. Mid-mount motors are mounted on the vehicle frame and transmit power to the rear wheel via a chain. Existing mid-mount motors typically occupy a large space and are inconvenient to install. In particular, the new national standard imposes stricter weight and speed limits on electric vehicles, making the previous mid-mount motor design no longer suitable. Summary of the Invention

[0003] The object of the present invention is to provide a mid-mounted motor with simple assembly in view of the shortcomings of the prior art.

[0004] To achieve the purpose, the present invention adopts the following technical solutions:

[0005] A mid-mounted motor comprises a rotor and a stator sleeved on the rotor, and further comprises an internally hollow stator housing, wherein the stator and rotor are both located within the stator housing, a motor shaft hole is opened on the rotor, a motor shaft is passed through the motor shaft hole, an input gear is provided on the motor shaft, a front end cover and a rear end cover are respectively installed at both ends of the stator housing, a second motor shaft cavity is formed on a side of the front end cover close to the stator housing, and a first gear cavity is formed on the other side of the front end cover, the second motor shaft cavity and the first gear cavity are connected through the front end cover hole, and the input gear passes through the front end cover hole and is located in the first gear cavity.

[0006] As a further optimization of the above technical solution: a first separation chamber and a second separation chamber are further formed on the side of the first gear chamber, the second separation chamber is adjacent to the first separation chamber, and a third separation chamber is further formed on the side of the second separation chamber.

[0007] As a further optimization of the above technical solution: the first gear chamber upper cover is provided with a gear outer cover, the gear outer cover is provided with a second gear chamber corresponding to the first gear chamber, and the gear outer cover is also provided with a fourth separation chamber corresponding to the first separation chamber, a fifth separation chamber corresponding to the second separation chamber, and a sixth separation chamber corresponding to the third separation chamber.

[0008] As a further optimization of the above technical solution: a first air gap is formed on the partition wall between the first partition chamber and the first gear chamber, a second air gap is formed on the partition wall between the second partition chamber and the third partition chamber, a third air gap is formed on the partition wall between the fourth partition chamber and the fifth partition chamber, an exhaust hole is formed on the partition wall between the sixth partition chamber and the fourth partition chamber, an air vent connected to the outside is formed on the fourth partition chamber, and an exhaust valve is installed on the air vent.

[0009] As a further optimization of the above technical solution: two oil holes are formed on the outer wall of the second gear cavity, and an oil filling and draining stud is installed on each of the oil holes.

[0010] As a further optimization of the above technical solution: the input gear and the motor shaft are formed in one piece.

[0011] As a further optimization of the above technical solution: an output gear is engaged with the input gear, an output shaft is passed through the center of the output gear, the output gear is exposed at both ends of the output shaft, a second limiting ring is formed on the output shaft, the output gear is tightly attached to the second limiting ring, a fourth bearing, a bushing, a fifth bearing and a second oil seal are provided on the output shaft, a plurality of positioning keys are formed on the end of the output shaft away from the second limiting ring, a sprocket is also sleeved on the output shaft, and a second keyway is formed on the sprocket to cooperate with the positioning key.

[0012] As a further optimization of the above technical solution: an encoder magnet, a first bearing, a second bearing, a first oil seal and a third bearing are provided on the motor shaft, a first limiting ring is made on the motor shaft, and the second bearing is tightly attached to the first limiting ring.

[0013] As a further optimization of the above technical solution: the first motor shaft cavity is formed on one side of the rear end cover close to the stator housing, and the encoder cavity is formed on the other side. The encoder cavity and the first motor shaft cavity are connected through the rear end cover hole. An encoder is installed in the encoder cavity. The encoder magnet passes through the rear end cover hole and cooperates with the encoder. The encoder cavity upper cover is provided with an encoder outer cover.

[0014] As a further optimization of the above technical solution: a mounting plate is provided on a side of the encoder close to the encoder cavity, and a plurality of movable holes are formed on the mounting plate. The movable holes are arranged around the encoder, and a plurality of threaded holes are formed in the encoder cavity. The shank of the screw passes through the movable hole and is fixed in the threaded hole. The cap head of the screw is in close contact with the mounting plate to install the encoder in the encoder cavity.

[0015] As a further optimization of the above technical solution: a hollow first waterproof connector is installed on the outer wall of the encoder cavity, and a phase line is connected to the waterproof connector. A hollow second waterproof connector is also installed on the outer wall of the encoder cavity, and a Hall line is connected to the second waterproof connector.

[0016] As a further optimization of the above technical solution: a first keyway is further formed on the side surface of the motor shaft, and a shaft key that matches the first keyway is formed on the hole wall of the motor shaft hole.

[0017] As a further optimization of the above technical solution: a threaded column is formed on the motor shaft, the threaded column passes through the rotor, a locking nut is installed on the threaded column, a positioning ring is provided on the motor shaft, the positioning ring is located between the locking nut and the rotor, a plurality of positioning grooves are formed on the locking nut, and a plurality of protruding first and second blocks are axially formed on the positioning ring, the first block is located in the first keyway, and the second block is located in the positioning groove.

[0018] As a further optimization of the above technical solution: a plurality of protruding positioning baffles are radially formed on the positioning ring, and the second clamping block is formed by bending the positioning baffles.

[0019] As a further optimization of the above technical solution: rotor baffles are further provided on both sides of the rotor, and the positioning ring is in close contact with one of the rotor baffles.

[0020] As a further optimization of the above technical solution: the first card block and the second card block are arranged back to back.

[0021] As a further optimization of the above technical solution: a plurality of magnetic steel holes and heat dissipation holes are opened on the rotor, and the heat dissipation holes are arranged around the motor shaft hole. Every two magnetic steel holes form a group arranged in a V shape around the heat dissipation holes. N-pole magnetic steel and S-pole magnetic steel are respectively arranged in two adjacent groups of magnetic steel holes, and the outer ring of the rotor is also made with a plurality of rotor bumps.

[0022] Compared with the prior art, the present invention replaces the spline connection between the motor shaft and the input gear by integrally forming the motor shaft and the input gear, which has higher transmission efficiency and lower noise; and replaces the installation of the gear box on the front end cover by directly forming a gear cavity on the front end cover, which has better waterproofness, simple assembly, simple structure and small space occupation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the explosion structure of the present invention.

[0024] Figure 2 It is a schematic diagram of the three-dimensional structure of the present invention.

[0025] Figure 3It is a structural schematic diagram of the rotor and stator in the present invention.

[0026] Figure 4 It is a schematic diagram of the three-dimensional structure of the motor shaft in the present invention.

[0027] Figure 5 It is a schematic diagram of the three-dimensional structure of the locking nut and the positioning ring in the present invention.

[0028] Figure 6 It is a schematic diagram of the three-dimensional structure of the output shaft in the present invention.

[0029] Figure 7 It is a schematic diagram of the three-dimensional structure of the front end cover in the present invention.

[0030] Figure 8 It is a schematic diagram of the three-dimensional structure of the gear outer cover in the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Figure 1-8 As shown, the central motor includes a rotor 7 and a stator 2 mounted on the rotor 7. The rotor 7 is provided with a plurality of magnetic steel holes 71, heat dissipation holes 72, and a motor shaft hole 73. The motor shaft 3 is passed through the motor shaft hole 73, and a shaft key 74 is formed on the wall of the motor shaft hole 73 to cooperate with the motor shaft 3. The heat dissipation holes 72 are arranged around the motor shaft hole 73, and every two magnetic steel holes 71 form a group arranged in a V shape around the heat dissipation holes 72. The adjacent two groups of magnetic steel holes 71 are respectively provided with an N-pole magnetic steel 76 and an S-pole magnetic steel 77. The outer ring of the rotor 7 is also provided with a plurality of rotor protrusions 75, which serve as magnetic conductors.

[0032] In the above technical solution: a threaded column 31 is formed on the motor shaft 3, and the threaded column 31 passes through the rotor 7. A locking nut 4 is installed on the threaded column 31. An annular positioning ring 5 is provided on the motor shaft 3, and the positioning ring 5 is located between the locking nut 4 and the rotor 7. A first keyway 32 that cooperates with the shaft key 74 is formed on the side of the motor shaft 3. The outer ring of the locking nut 4 is formed with a plurality of positioning grooves 41. The outer ring of the positioning ring 5 is radially formed with a plurality of protruding positioning baffles 51, and the inner ring of the positioning ring 5 is axially formed with a plurality of protruding first clamping blocks 52 and a plurality of second clamping blocks 53. The first clamping blocks 52 and the second clamping blocks 53 can be arranged back to back, with the first clamping block 52 located in the first keyway 32 and the second clamping block 53 located in the positioning groove 41. In this embodiment, the second clamping block 53 is formed by bending the positioning baffle 51. That is, after the locking nut 4 is tightened on the threaded column 31, part of the positioning baffle 51 corresponds to the position of part of the positioning groove 41, and the positioning baffle 51 corresponding to the position of the positioning groove 41 is bent to form a second clamping block 53, and the second clamping block 53 is clamped into the positioning groove 41. In this embodiment, the provision of multiple positioning baffles 51 increases the probability that the locking nut 4 corresponds to the position of the positioning groove 41 after being tightened. Rotor baffles 78 are also provided on both sides of the rotor 7, and the positioning ring 5 is in close contact with one of the rotor baffles 78. The positioning ring 5 cooperates with the locking nut 4 and the motor shaft 3 to prevent relative rotation between the locking nut and the motor shaft. The positioning ring 5 is in close contact with the rotor baffle 78 on the side of the rotor 7, and the rotor part has a good fixing effect, the motor runs more stably, the dynamic balance effect is better, and the drift is smaller.

[0033] In the above technical solution: a first gear shaft 33 is formed at the end of the threaded column 31 , a first bearing 6 is sleeved on the first gear shaft 33 , and an encoder magnet 1 is also provided at the end of the first gear shaft 33 .

[0034] In the above technical solution, the motor shaft 3 is provided with a first retaining ring 34, a connecting post 35 being provided on one side of the first retaining ring 34, an input gear 36 being provided at one end of the connecting post 35, and a second gear shaft 37 being provided at the end of the motor shaft 3 near the input gear 36. A second bearing and a first oil seal 8 are provided on the connecting post 35, with the second bearing being located near the first retaining ring 34. A third bearing 9 is provided on the second gear shaft 37.

[0035] In the above technical solution: the input gear 36 is meshed with the output gear 10, and the output shaft 11 is passed through the center of the output gear 10, and the output gear 10 is exposed at both ends of the output shaft 11. The output shaft 11 is provided with a second limiting ring 111, which serves to limit the output gear 10. The end of the output shaft 11 close to the second limiting ring 111 is provided with a third gear shaft 112, and the third gear shaft 112 is provided with a fourth bearing 12. The output shaft 11 is also provided with a sleeve, a fifth bearing 13 and a second oil seal 14. The end of the output shaft 11 away from the second limiting ring 111 is provided with a plurality of positioning keys 113. The output shaft 11 is also provided with a sprocket 15, and the sprocket 15 is provided with a second keyway that cooperates with the positioning keys 113.

[0036] The above technical solution also includes a stator housing 16 with a hollow interior, in which the stator 2 and rotor 7 are both located. A front cover 17 and a rear cover 18 are mounted on both ends of the stator housing 16, respectively. A first motor shaft cavity is formed on the side of the rear cover 18 close to the stator housing 16, and an encoder cavity 181 is formed on the other side. The encoder cavity 181 and the first motor shaft cavity are connected via a rear cover hole 182. An encoder 19 is mounted in the encoder cavity 181. A mounting plate 191 is provided on the side of the encoder 19 close to the encoder cavity 181. The mounting plate 191 is provided with a plurality of arc-shaped movable holes 192, which are arranged around the encoder 19. The encoder cavity 181 is provided with a plurality of threaded holes. The shanks of the screws pass through the movable holes 192 and are fixed in the threaded holes. The caps of the screws are in close contact with the mounting plate 191, thereby mounting the encoder 19 in the encoder cavity 181. The movable hole 192 allows the encoder 19 to rotate within the encoder cavity 181 without being disassembled, making it easier to adjust the position of the encoder 19. The encoder magnet 1 passes through the rear cover hole 182 and engages with the encoder 19. The encoder cavity 181 is covered with an encoder outer cover 20.

[0037] In the above technical solution, three hollow first waterproof connectors 21 are mounted on the outer wall of the encoder cavity 181, each of which is connected to a phase line 22. These first waterproof connectors 21 are conventional. Also mounted on the outer wall of the encoder cavity 181 is a hollow second waterproof connector 23, to which a Hall line 24 is connected. These second waterproof connectors 23 are conventional.

[0038] In the above technical solution, a second motor shaft cavity 171 is formed on one side of the front cover 17 adjacent to the stator housing 16, and a first gear cavity 172 is formed on the other side of the front cover 17. The second motor shaft cavity 171 and the first gear cavity 172 are connected via a front cover hole 173. The input gear 36 on the motor shaft 3 passes through the front cover hole 173 and is located in the first gear cavity 172. The output gear 10 is also located in the first gear cavity 172.

[0039] In the above technical solution: the first gear cavity 172 is covered with a gear outer cover 25 , the gear outer cover 25 is formed with a sprocket hole 257 , and the positioning key 113 passes through the sprocket hole 257 to cooperate with the sprocket 15 .

[0040] In the above technical solution, the first gear cavity 172 is further formed with a first partition cavity 174 and a second partition cavity 175 on its side. The second partition cavity 175 is adjacent to the first partition cavity 174, and a third partition cavity 176 is further formed on its side. The gear outer cover 25 is formed with a second gear cavity 251 corresponding to the first gear cavity 172. The gear outer cover 25 is also formed with a fourth partition cavity 252 corresponding to the first partition cavity 174, a fifth partition cavity 253 corresponding to the second partition cavity 175, and a sixth partition cavity 254 corresponding to the third partition cavity 176. A first air gap 177 is formed in the partition wall between the first partition chamber 174 and the first gear chamber 172. A second air gap 178 is formed in the partition wall between the second partition chamber 175 and the third partition chamber 176. A third air gap 256 is formed in the partition wall between the fourth partition chamber 252 and the fifth partition chamber 253. An exhaust hole is formed in the partition wall between the sixth partition chamber 254 and the fourth partition chamber 252. A vent hole 255 communicating with the outside is formed in the fourth partition chamber 252, and an exhaust valve 26 is mounted on the vent hole 255. The vent hole 255 is separated from the first and second gear chambers 172 and 251 by the first and fourth partition chambers 174 and 252. This prevents oil from leaking out of the vent hole 255 when the gears in the first and second gear chambers 172 and 251 rotate and splash, thereby resolving the problem of oil leakage from the vent hole 255. The first exhaust passage passes through the first air gap 177, the first partition chamber 174, the fourth partition chamber 252 and the vent 255. The first air gap 177 connects the first and second gear chambers 172 and 251 with the vent 255. The second exhaust passage passes through the first air gap 177, the first partition chamber 174, the fourth partition chamber 252, the vent, the sixth partition chamber 254, the third partition chamber 176, the second air gap 178, the second partition chamber 175, the fifth partition chamber 253, the third air gap 256, the fourth partition chamber 252 and the vent 255. The third air gap 256, the second air gap 178 and the vent connect the second, third, fifth and sixth partition chambers 175, 176, 253 and 254 with the vent. After the motor has been running for a long time, it generates a lot of heat, and the temperature in the first gear chamber 172 and the second gear chamber 251 increases. In addition, when the motor is operating, it is necessary to ensure that lubricating oil is added between each gear. The lubricating oil lubricates the rotation process of the gears, but when the gears rotate, the lubricating oil will splash. The splashing lubricating oil fully contacts the high-temperature gas, generating high-pressure gas. The high-pressure gas in the first and second gear chambers 172 and 251 can be discharged through the first exhaust channel or the second exhaust channel. The exhaust valve 26 ensures that the air pressure in the first and second gear chambers 172 and 251 is stable. The first exhaust channel and the second exhaust channel are connected. A single exhaust channel may cause high-pressure gas to burst the exhaust valve.A second exhaust passage is provided to divert the high-pressure gas within the fourth compartment 252. A portion of the high-pressure gas flows along the first exhaust passage and is discharged through the exhaust valve 26 on the vent 255. Another portion of the high-pressure gas flows along the second exhaust passage from the fourth compartment 252 through the vent into the sixth compartment 254. The gas then passes through the third compartment 176, the second air gap 178, the second compartment 175, the fifth compartment 253, and the third air gap 256 before returning to the fourth compartment 252 and being discharged through the exhaust valve 26 on the vent 255. The second, third, fifth, and sixth compartments 175, 176, 253, and 254 act as buffers for the high-pressure gas, preventing it from breaching the exhaust valves and ensuring stable pressure within the first and second gear chambers 172 and 251.

[0041] In the above technical solution, two oil holes are formed on the outer wall of the second gear cavity 251, each of which is equipped with an oil filling and draining stud 27. By removing the oil filling and draining stud 27 from the oil hole, the second gear cavity 251 can be filled or drained through the oil hole, ensuring normal operation of the gear.

[0042] In the above technical solution, the first bearing 6 is fixed to the inner wall of the first motor shaft cavity. The second bearing is fixed to the inner wall of the second motor shaft cavity 171. The third bearing 9 is fixed in the second gear cavity 251. The fourth bearing 12 is fixed in the first gear cavity 172.

[0043] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should fall within the scope of protection of the present invention.

Claims

1. A mid-mounted motor, comprising a rotor (7) and a stator (2) sleeved on the rotor (7), and further comprising a stator housing (16) with a hollow interior, wherein the stator (2) and the rotor (7) are both located within the stator housing (16), a motor shaft hole (73) is provided on the rotor (7), and a motor shaft (3) is passed through the motor shaft hole (73), characterized in that An input gear (36) is provided on the motor shaft (3), and a front end cover (17) and a rear end cover (18) are respectively installed at both ends of the stator housing (16). A second motor shaft cavity (171) is formed on a side of the front end cover (17) close to the stator housing (16), and a first gear cavity (172) is formed on the other side of the front end cover (17). The second motor shaft cavity (171) and the first gear cavity (172) are connected through a front end cover hole (173), and the input gear (36) passes through the front end cover hole (173) and is located in the first gear cavity (172). A first separation chamber (174) and a second separation chamber (175) are further formed on the side of the first gear chamber (172); the second separation chamber (175) is adjacent to the first separation chamber (174); and a third separation chamber (176) is further formed on the side of the second separation chamber (175); The upper cover of the first gear chamber (172) is provided with a gear outer cover (25), and the gear outer cover (25) is provided with a second gear chamber (251) corresponding to the first gear chamber (172). The gear outer cover (25) is also provided with a fourth separation chamber (252) corresponding to the first separation chamber (174), a fifth separation chamber (253) corresponding to the second separation chamber (175), and a sixth separation chamber (254) corresponding to the third separation chamber (176). A first air gap (177) is formed on the partition wall between the first partition chamber (174) and the first gear chamber (172), a second air gap (178) is formed on the partition wall between the second partition chamber (175) and the third partition chamber (176), a third air gap (256) is formed on the partition wall between the fourth partition chamber (252) and the fifth partition chamber (253), an exhaust hole is formed on the partition wall between the sixth partition chamber (254) and the fourth partition chamber (252), a vent hole (255) communicating with the outside is formed on the fourth partition chamber (252), and an exhaust valve (26) is installed on the vent hole (255).

2. A mid-mounted motor according to claim 1, characterized in that Two oil holes are formed on the outer wall of the second gear cavity (251), and an oil filling and draining stud (27) is installed on each of the oil holes.

3. A mid-mounted motor according to claim 1, characterized in that The input gear (36) and the motor shaft (3) are integrally formed.

4. A mid-mounted motor according to claim 1, characterized in that The input gear (36) is meshed with an output gear (10), an output shaft (11) is provided through the center of the output gear (10), both ends of the output shaft (11) are exposed from the output gear (10), a second limiting ring (111) is formed on the output shaft (11), the output gear (10) is closely attached to the second limiting ring (111), a fourth bearing (12), a shaft sleeve, a fifth bearing (13) and a second oil seal (14) are provided on the output shaft (11), a plurality of positioning keys (113) are formed at the end of the output shaft (11) away from the second limiting ring (111), a sprocket (15) is further sleeved on the output shaft (11), and a second keyway is formed on the sprocket (15) to cooperate with the positioning key (113).

5. A mid-mounted motor according to claim 1, characterized in that An encoder magnet (1), a first bearing (6), a second bearing, a first oil seal (8), and a third bearing (9) are provided on the motor shaft (3). A first limiting ring (34) is formed on the motor shaft (3), and the second bearing is in close contact with the first limiting ring (34).

6. A mid-mounted motor according to claim 5, characterized in that A first motor shaft cavity is formed on one side of the rear end cover (18) close to the stator housing (16), and an encoder cavity (181) is formed on the other side. The encoder cavity (181) and the first motor shaft cavity are communicated through a rear end cover hole (182). An encoder (19) is installed in the encoder cavity (181). The encoder magnet (1) passes through the rear end cover hole (182) and cooperates with the encoder (19). An encoder outer cover (20) is provided on the upper cover of the encoder cavity (181). A mounting plate (191) is provided on one side of the encoder (19) close to the encoder cavity (181), and a plurality of movable holes (192) are formed on the mounting plate (191). The movable holes (192) are arranged around the encoder (19), and a plurality of threaded holes are formed in the encoder cavity (181). The shank of the screw passes through the movable hole (192) and is fixed in the threaded hole. The cap head of the screw is in close contact with the mounting plate (191), so that the encoder (19) is mounted in the encoder cavity (181).

7. A mid-mounted motor according to claim 6, characterized in that A hollow first waterproof joint (21) is mounted on the outer wall of the encoder cavity (181), and a phase line (22) is connected to the waterproof joint. A hollow second waterproof joint (23) is also mounted on the outer wall of the encoder cavity (181), and a Hall line (24) is connected to the second waterproof joint (23).

8. The mid-mounted motor according to claim 1, characterized in that A first keyway (32) is also formed on the side surface of the motor shaft (3), and a shaft key (74) that cooperates with the first keyway (32) is formed on the hole wall of the motor shaft hole (73).

9. A mid-mounted motor according to claim 8, characterized in that A threaded column (31) is formed on the motor shaft (3), the threaded column (31) passes through the rotor (7), a locking nut (4) is mounted on the threaded column (31), a positioning ring (5) is provided on the motor shaft (3), the positioning ring (5) is located between the locking nut (4) and the rotor (7), the locking nut (4) is formed with a plurality of positioning grooves (41), and the positioning ring (5) is axially formed with a plurality of protruding first clamping blocks (52) and second clamping blocks (53), the first clamping block (52) is located in the first keyway (32), and the second clamping block (53) is located in the positioning groove (41).

10. A mid-mounted motor according to claim 9, characterized in that A plurality of protruding positioning baffles (51) are radially formed on the positioning ring (5), and the second clamping block (53) is formed by bending the positioning baffles (51).

11. The mid-mounted motor according to claim 9, characterized in that Rotor baffles (78) are also provided on both sides of the rotor (7), and the positioning ring (5) is in close contact with one of the rotor baffles (78).

12. The mid-mounted motor according to claim 9, characterized in that The first clamping block (52) and the second clamping block (53) are arranged back to back.

13. The mid-mounted motor according to claim 1, characterized in that The rotor (7) is provided with a plurality of magnetic steel holes (71) and heat dissipation holes (72). The heat dissipation holes (72) are arranged around the motor shaft hole (73). Every two magnetic steel holes (71) form a group arranged in a V-shape around the heat dissipation holes (72). N-pole magnetic steel (76) and S-pole magnetic steel (77) are respectively provided in two adjacent groups of magnetic steel holes (71). The outer ring of the rotor (7) is also provided with a plurality of rotor protrusions (75).

Images