Internal rotor motor

Abstract

To provide an internal rotor motor that includes a stator and a rotor that rotates relatively to the stator.SOLUTION: A stator includes a stator housing, a magnet disposed within the stator housing, and at least two electrical connection terminals, and a rotor includes a core, a shaft fixed to the core, a coil wound around the core, and a slip ring sleeved on the shaft, the slip ring includes at least two conductive rings disposed at intervals in the radial direction, the conductive rings are electrically connected to the coils, the at least two electrical connection terminals are disposed on one axial side of the slip ring, one end of each electrical connection terminal is in contact with and electrically conducts with a corresponding conductive ring, and the other end of each electrical connection terminal receives alternating current. Since the conductive rings of the motor according to the present application are disposed at intervals in the radial direction, the slip ring has a relatively small axial dimension, and the core of the rotor can maintain a relatively large axial dimension to enhance the performance of the motor.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD

[0001] The present application relates to the field of motor technology, and particularly relates to an inner rotor motor. BACKGROUND ART

[0002] A motor consists of a stator and a rotor that rotate relative to each other. Based on the positional relationship between the stator and the rotor, motors can be divided into two main types: inner rotor motors and outer rotor motors. The stator of an inner rotor motor includes a stator housing, magnets fixed to the inner wall of the stator housing, and a plurality of brushes. The rotor includes a core, coils wound around the core, and a slip ring that rotates together with the rotating shaft. The slip ring is substantially cylindrical and includes a plurality of conductive rings that are arranged at intervals in the axial direction and electrically connected to the coils. During the rotation of the rotor, an external alternating current is transmitted to the coils through the plurality of brushes and the conductive rings. The motor transmits alternating current to the coils via the brushes and the slip ring without requiring a conventional commutator for mechanical commutation, effectively improving the service life of the motor.

[0003] However, since the conductive rings are arranged along the axial direction and occupy a relatively large axial space, the axial length of the motor becomes relatively large. When it is necessary to limit the axial length of the motor within a certain range, the rotor core needs to be shortened, which leads to a decrease in the performance of the motor. SUMMARY OF THE INVENTION

[0004] In view of this point, an inner rotor motor that takes motor performance and motor size into consideration is provided.

[0005] The internal rotor motor includes a stator and a rotor rotatable relative to the stator, the stator including a stator housing, at least one magnet disposed within the stator housing, and at least two electrical connection terminals, the rotor including a core, a shaft fixed to the core, a coil wound around the core, and a slip ring sleeve-connected to the shaft, the slip ring including at least two conductive rings arranged radially apart, these conductive rings being electrically connected to the coil, and at least two electrical connection terminals located on one axial side of the slip ring, with one end of each electrical connection terminal in contact with the corresponding conductive ring for electrical conduction, and the other end of each electrical connection terminal configured to receive alternating current.

[0006] Compared to conventional technology, in the internal rotor motor of this application, the conductive rings are arranged with radial spacing, so the slip rings have a relatively small axial dimension, and the rotor core can maintain a relatively large axial dimension, thereby improving the performance of the motor. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram of the internal rotor motor in the embodiment of this application. [Figure 2] Figure 1 is an exploded view of the internal rotor motor. [Figure 3] Figure 2 is a further exploded view of the internal rotor motor. [Figure 4] Figure 3 is an exploded front view of the internal rotor motor. [Figure 5] Figure 1 is a cross-sectional view of the internal rotor motor. [Figure 6] Figure 1 is a top view of the slip rings of the internal rotor motor. [Figure 7] Figure 1 is a schematic diagram of the insulating base and conductive terminals of the internal rotor motor shown. [Figure 8] Figure 1 is a schematic diagram of the slip rings, electrical connection terminals, and power connection elements of the internal rotor motor shown. [Figure 9] This is a schematic diagram of the elastic arm of the internal rotor motor shown in Figure 1, according to another embodiment of this application. [Modes for carrying out the invention]

[0008] To facilitate understanding of this application, a more comprehensive description is provided below with reference to the relevant accompanying drawings. The drawings illustrate one or more embodiments of this application and will provide a more thorough and accurate understanding of the technical solutions disclosed herein. However, it should be understood that this application is implementable in various forms and is not limited to the embodiments described below.

[0009] In the drawings accompanying this application, the same or similar reference numerals correspond to the same or similar components. It should be understood that in this application, terms such as “up,” “down,” “left,” and “right” are used to indicate positional or directional relationships based on the directions or positions shown in the drawings. These terms are merely for illustrative purposes and to simplify the explanation, and do not indicate or imply that the devices or elements mentioned have a particular orientation or must be configured and operated in a particular orientation. Therefore, the terms used in the drawings to describe positional relationships are merely illustrative and should not be understood as limiting the invention. The specific meanings of the aforementioned terms can be understood by those skilled in the art based on specific circumstances.

[0010] This application provides an internal rotor motor, and Figures 1-3 illustrate specific embodiments of this application. The internal rotor motor includes a stator 10 and a rotor 30 rotatably disposed within the stator 10.

[0011] The stator 10 includes a stator housing 12, at least one magnet 14 fixed to the inner wall of the stator housing 12, and at least two electrical connection terminals 15. The at least one magnet 14 is preferably two or more magnets spaced apart along the circumferential direction of the stator housing 12, forming north and south poles in the circumferential direction of the stator housing 12. Alternatively, the at least one magnet 14 can be an annular magnet, which includes two or more magnetic poles along the circumferential direction and also forms north and south poles in the circumferential direction of the stator housing 12. The magnet 14 is preferably made of ferrite. If cost is not a consideration, the magnet 14 can also be a permanent magnet made from a strong magnetic material such as neodymium iron boron, or the magnet 14 can be an electromagnet that generates a stable magnetic field when energized. Preferably, at least two electrical connection terminals 15 are spaced apart in the circumferential direction.

[0012] Referring to Figures 4 and 5, the rotor 30 includes a shaft 31, a core 32, a coil 34 wound around the core 32, and a slip ring 36 sleeve-connected to the shaft 31. The shaft 31 is fixed within the core 32. The slip ring 36 is electrically connected to the coil 34. The core 32 can be made from stacked silicon steel sheets, including a yoke portion sleeve-connected onto the shaft 31 and a plurality of teeth extending radially outward from the yoke portion. The shaft 31 can be inserted into the yoke portion of the core 32, with both ends of the shaft extending beyond the core 32. The coil 34 is wound around each of the teeth, with adjacent teeth spaced circumferentially to form winding slots for the coil 34.

[0013] Referring to Figure 6, the slip ring 36 includes at least two conductive rings 361 arranged radially apart. The at least two conductive rings 361 are concentric rings. In this embodiment, the slip ring 36 is substantially plate-shaped. The surface of the conductive ring 361 for receiving power is perpendicular to the axial direction. Preferably, the slip ring 36 is a printed circuit board that rotates with the shaft 31. At least two annular conductive traces are formed on one side (the first side) of the printed circuit board facing the electrical connection terminals 15. The at least two annular conductive traces form at least two conductive rings 361. Preferably, at least two pads are also formed on the surface of the printed circuit board. Each of the at least two pads is connected to the corresponding conductive trace via an internal circuit within the printed circuit board. More preferably, at least two pads are formed on the other side (the second side) of the printed circuit board and are positioned closer to the shaft 31.

[0014] The electrical connection terminal 15 is located on one axial side of the slip ring 36. One end of the electrical connection terminal 15 is conductive in contact with the corresponding conductive ring 361, and the other end of the electrical connection terminal 15 is configured to receive alternating current.

[0015] The coil 34 can be a multiphase coil or a single-phase coil. If the coil 34 is a multiphase coil, the number of conductive rings 361 and the number of electrical connection terminals 15 are both equal to or greater than the number of phases in the multiphase coil, and each phase coil is electrically connected to one of the conductive rings 361, so that each phase coil can conduct to alternating current through one conductive ring and one electrical connection terminal 15 in contact with the conductive ring. Preferably, the number of conductive rings 361 and the number of electrical connection terminals 15 are both equal to the number of phases in the multiphase coil. If the coil 34 is a single-phase coil, the number of conductive rings 361 and the number of electrical connection terminals 15 are both 2. The two conductive rings 361 are connected to the front and rear ends of the single-phase coil, and each end of the single-phase coil can conduct to alternating current through one conductive ring 361 and one electrical connection terminal 15 in contact with the conductive ring 361.

[0016] In this embodiment, the coil 34 is a three-phase coil (U, V, W), and the three-phase coil can be a star connection (Y connection) or a delta connection (Δ connection), which are commonly used in three-phase motors. Each phase coil 34 can consist of multiple coils connected in parallel or in series, and therefore the alternating current is a three-phase alternating current. Below, the internal rotor motor of this application will be described using the three-phase coil, three conductive rings 361, and three electrical connection terminals 15 as examples. When the internal rotor motor starts, a three-phase alternating current is conducted to the three-phase coils of the rotor via the three electrical connection terminals 15 and the three conductive rings 361. The alternating current can be a sine wave, a square wave, etc., and the currents in each phase coil can form a phase difference of 120 degrees, thereby generating a rotating magnetic field that allows the rotor 30 to rotate continuously relative to the stator 10. While the rotor 30 is rotating, the electrical connection terminals 15 and the conductive rings 361 maintain their conductive state and perform the function of electrical connection.

[0017] It should be understood that the coils of the rotor 30 may be configured with any number of phases, such as 4 phases, 5 phases, etc. In this case, the number of the conductive rings 361 and the number of the electrical connection terminals 15 are adjusted according to the number of phases of the coils 34, and each conductive ring 361 conducts one phase coil and an alternating current. In the embodiments of the present application, only a three-phase coil is taken as an example, but the present application is not limited thereto.

[0018] Compared with the prior art, since at least two conductive rings 361 are arranged at intervals in the radial direction, the slip ring 36 has a relatively small axial dimension, and the core 32 of the rotor 30 can maintain a relatively large axial dimension to improve the performance of the motor. The inner rotor motor of the present application is particularly suitable for motors with small outer diameters (for example, motors with an outer diameter of 26 mm or less).

[0019] Preferably, referring to FIG. 7, the rotor 30 further includes an insulating base 38 and at least two conductive terminals 39. The insulating base 38 is sleeved on the shaft 31, and the conductive terminals 39 are fixed by the insulating base 38. Preferably, the insulating base 38 is made of bakelite. Preferably, the insulating base 38 is injection molded over the conductive terminals 39. At least a part of the insulating base 38 is disposed on the side surface of the slip ring 36 adjacent to the core 32. The number of the conductive terminals 39 is the same as the number of the conductive rings 361. One end of each conductive terminal 39 is connected to the coil 34, and the other end is electrically connected to the corresponding conductive ring 361.

[0020] Preferably, the rotor 30 further includes a first sleeve 41, and the sleeve 41 is tightly mounted on the shaft 31. Preferably, the sleeve 41 is a metal sleeve. The slip ring 36 is disposed between the sleeve 41 and the insulating base 38 in the axial direction.

[0021] Preferably, one end of the insulating base 38 facing the first sleeve 41 has a first protruding portion 380. The axial end face of the first protruding portion 380 abuts against the first sleeve 41, whereby the first sleeve 41 can limit the axial position of the insulating base 38. The first protruding portion 380 can directly abut against the first sleeve 41, or can indirectly abut against the first sleeve 41 via an element such as a washer. First protrusion 380 On the plane perpendicular to the shaft 31 fart of projection is Insulating base 38 on the same plane fart of projection is smaller than that, whereby the area that axially abuts against the first sleeve 41 is reduced. Since the first protruding portion 380 has a smaller axial end face, the flatness can be better controlled and guaranteed, thus enabling a better fit for axial positioning with the first sleeve 41. In this embodiment, the first protruding portion 380 is a ring-shaped protruding portion. In other embodiments, the first protruding portion 380 can also be at least one arc-shaped protruding portion or at least two protruding portions arranged at intervals in the circumferential direction. The slip ring 36 is sleeved on the outer periphery of the first protruding portion 380, and is disposed between the first sleeve 41 and the insulating base 38 in the axial direction.

[0022] Preferably, an anti-rotation protrusion 381 is formed on the radially outer portion of the first protruding portion 380, and a groove 363 that engages with the anti-rotation protrusion 381 to prevent relative rotation between the insulating base 38 and the slip ring 36 is formed on the radially inner side of the slip ring 36. It can also be understood that an anti-rotation groove can be formed on the radially outer side of the first protruding portion 380, while a protrusion that engages with the anti-rotation groove to prevent relative rotation between the insulating base 38 and the slip ring 36 is formed on the radially inner side of the slip ring 36.

[0023] Preferably, one end of the insulating base 38 facing the core 32 has a second projection 383. The axial end face of the second projection 383 abuts against the core 32. The second projection 383 can abut directly against the core 32 or abut indirectly against the core 43 via an element such as a second sleeve 43 and / or washer. Second protrusion 383 On a plane perpendicular to shaft 31 fart of projection teeth, Insulating base 38 On the same plane fart of projection This reduces the area that contacts the core axially, as it is smaller than the first projection. The second projection 383 has a smaller axial end face, which allows for better control and assurance of flatness and enables better axial positioning. In this embodiment, the second projection 383 is an annular projection. In other embodiments, the second projection 383 may also be at least one arcuate projection or at least two projections spaced apart in the circumferential direction.

[0024] Referring to Figure 5, each conductive terminal 39 includes a slip ring connector 391, a hook portion 393, and a positioning portion 395 connected between the slip ring connector 391 and the hook portion 393. The hook portion 393 is connected to the coil 34. The positioning portion 395 is fixed within an insulating base 38. Preferably, the positioning portion 395 can be fixed within the insulating base 38 by injection molding. It can also be understood that the positioning portion 395 can be fixed within the insulating base 38 by insertion or other means. The slip ring connector 391 of the conductive terminal 39 is electrically connected to the corresponding conductive ring 361, respectively. In this embodiment, the slip ring connector 391 extends radially. The positioning portion 395 and the slip ring connector 391 together form an opening that faces outward along the radial direction. The slip ring connector 391 is soldered to a pad on a printed circuit board. The hook portion 393 has a slot that communicates with the opening. The open end of the slot faces outward from the core 32 in the axial direction. Preferably, depending on the winding requirements, the hook portion 393 of each conductive terminal 39 may have one or more hooks for connection to the coil 34. Multiple hooks of the same conductive terminal 39 are at the same potential.

[0025] Preferably, a reinforcing rib 385 is provided on the axial end face of the insulating base 38, and the position of this reinforcing rib 385 is close to the hook portion 393, so that this portion of the insulating base 38 has higher strength and prevents damage to this portion when the conductive terminal 39 bends to form the hook portion 393.

[0026] Preferably, referring to Figure 8, each electrical connection terminal 15 includes a power receiving portion 151 positioned axially spaced from the slip ring 36, and an elastic arm 153 extending from the power receiving portion 151 toward the slip ring 36. The elastic arm 153 elastically contacts the corresponding conductive ring 361 to prevent a gap between the electrical connection terminal 15 and the conductive ring 361, ensuring good contact between the electrical connection terminal 15 and the conductive ring 361 to avoid non-conductivity due to poor contact. An angle is formed between the extending direction of the elastic arm 153 and the axial direction of the internal rotor motor. This angle is greater than 0 degrees and less than 90 degrees. Preferably, this angle is between 35 degrees and 55 degrees.

[0027] Preferably, a bulge 154 is formed at the end of the elastic arm 153, and this bulge 154 contacts and is conductive with the corresponding conductive ring 361. The surface of the bulge 154 is preferably spherical or elliptical, but is not limited thereto. The contact between the bulge 154 and the conductive ring 361 reduces the contact area, thereby reducing wear and allowing the electrical connection terminals 15 to make smooth contact with the conductive ring 361 as the rotor 30 rotates. In other embodiments, the end of the elastic arm 153 may not have a bulge 154, and the end of the elastic arm 153 may contact the conductive ring 361 via a carbon brush.

[0028] Referring to Figure 9, in another embodiment, the electrical connection terminal 15 includes two elastic arms 155 extending from the power receiving section 151 toward the conductive ring. The two elastic arms 155 are positioned counterclockwise and clockwise relative to the power receiving section 151, respectively. By having the two elastic arms 155 abut against the same conductive ring 361, better conductivity can be ensured between the elastic arms 155 and the conductive ring 361.

[0029] Preferably, the stator 10 further includes an end cover 17, which is fixed to one axial end of the stator housing 12. The other axial side of the stator housing has a cap 121. In this embodiment, the cap 121 and the stator housing 12 are integrally formed as a single structure, although it can be understood that the cap 121 may also be formed independently of the stator housing 12 and then assembled into a single unit. The stator 10 may further include a cover plate 18 fixed to the end cover 17. Preferably, the cap 121 has a bearing seat for mounting a bearing 19, and the end cover 17 or cover plate 18 also has a bearing seat for mounting a bearing 19. Both ends of the shaft 31 are inserted into one bearing 19 each, and the bearings 19 provide support for the shaft 31, allowing the rotor 30 to rotate smoothly. At least two electrical connection terminals 15 are fixed to the end cover 17.

[0030] The end cover 17 has a first engagement block 171 and a second engagement block 173. The first engagement block 171 protrudes from one axial side of the end cover 17, and the second engagement block 173 protrudes from the outer circumference of the end cover 17. The cover plate 18 has a first engagement groove 181 and a second engagement groove 183. The first engagement block 171 engages with the first engagement groove 181. The second engagement block 173 engages with the notch 123 at one end of the stator housing 12 and the second engagement groove 183, thereby integrally fixing the end cover 17, the cover plate 18, and the stator housing 12.

[0031] Preferably, the internal rotor motor of this application also includes at least two power connection elements 16 for receiving power. The power connection elements 16 are fixed to the end cover 17. Specifically, referring to Figure 9, the power connection element 16 has an axially extending portion 161 and a radially extending portion 163. The axially extending portion 161 projects away from the slip ring 36 toward the end cover 17. The radially extending portion 163 is located toward the end cover 17 closer to the slip ring 36 to provide axial positioning for the power connection element 16.

[0032] In this embodiment, the number of power connection elements 16 is the same as the number of electrical connection terminals 15. One end of each power connection element 16 extends outside the end cover 17 to receive alternating current, and the other end is connected to the corresponding electrical connection terminal 15 to transmit the alternating current to the electrical connection terminal 15. Preferably, the radially extending portion 163 of each power connection element 16 is fixedly connected to the power receiving portion 151 of each electrical connection terminal 15 by riveting, welding, or the like.

[0033] In other embodiments, the power connection element 16 can also be used to receive DC. In this case, the internal rotor motor further integrates a DC-to-AC conversion circuit, which is configured to convert the DC current to AC current and then transmit the AC current to the electrical connection terminal 15.

[0034] This application is not limited to the embodiments described above. Those skilled in the art can make other modifications in accordance with the spirit of this application, and all such modifications made in accordance with the spirit of this application should be included within the scope of protection claimed in this application. [Explanation of Symbols]

[0035] 10 staters 12 Stator Housing 14 Magnets 15 Electrical connection terminals 16 Power connection elements 17 End cover 18 Cover Plate 19 battalions 30 rotors 31 shafts 32 cores 34 coils 36 Slip Rings 38 Insulating base 39 Conductive terminals 41 First Sleeve 43. Second sleeve 121 Cap 123 Notches 151 Power receiving section 153(155) Elastic Arm 154 Bulge 161 Part extending in the axial direction 163 Radially extending portion 171 First engagement block 173 Second engagement block 181 First engagement groove 183 Second engagement groove 361 Conductive Ring 363 Groove 380 First protrusion 381 Anti-rotation protrusion 383 Second projection 385 Reinforcement Ribs 391 Slip ring connection 393 Hook part 395 Positioning section

Claims

1. An internal rotor motor comprising a stator and a rotor rotatable relative to the stator, wherein the stator comprises a stator housing, at least one magnet disposed within the stator housing, and at least two electrical connection terminals, and the rotor comprises a core, a shaft fixed to the core, a coil wound around the core, and a slip ring, wherein the shaft passes through the slip ring, and the slip ring comprises at least two conductive rings arranged radially apart and electrically connected to the coil, and the at least two electrical connection terminals are arranged on one axial side of the slip ring, and one end of each electrical connection terminal is in contact with the corresponding conductive ring for electrical conductivity, and the other end of each electrical connection terminal is configured to receive alternating current. The slip ring is a printed circuit board that rotates with the shaft, and at least two annular conductive traces are formed on the surface of the printed circuit board away from the core, and the at least two annular conductive traces form the at least two conductive rings. An internal rotor motor characterized by the following features.

2. The coil is a multiphase coil, and the number of at least two conductive rings and the number of at least two electrical connection terminals are both equal to or greater than the number of phases of the multiphase coil, and each phase coil receives alternating current through a corresponding conductive ring and an electrical connection terminal in contact with the conductive ring. The internal rotor motor according to claim 1, characterized in that

3. The slip ring is plate-shaped, and the rotor further comprises an insulating base fitted onto the shaft and at least two conductive terminals fixed by the insulating base, at least a portion of the insulating base located on the side of the slip ring closer to the core, the number of the at least two conductive terminals is the same as the number of the at least two conductive rings, one end of each conductive terminal is connected to the coil, and the other end of each conductive terminal is electrically connected to the corresponding conductive ring. An internal rotor motor according to claim 1 or 2, characterized in that

4. The rotor further comprises a sleeve firmly attached to the shaft, and the slip ring is axially positioned between the sleeve and the insulating base. The internal rotor motor according to claim 3, characterized in that

5. One end of the insulating base facing the sleeve has a projection, the axial end face of the projection abuts the sleeve directly or indirectly, the projection of the projection onto a plane perpendicular to the shaft is smaller than the projection of the insulating base onto the plane, and the slip ring is fitted onto the outer circumference of the projection. The internal rotor motor according to claim 4, characterized in that

6. A rotation-preventing projection is formed on the radially outer side of the protruding portion, and a groove is formed on the radially inner side of the slip ring, and the groove engages with the rotation-preventing projection to prevent relative rotation between the insulating base and the slip ring, or a rotation-preventing groove is formed on the radially outer side of the protruding portion, and a projection is formed on the radially inner side of the slip ring, and the projection engages with the rotation-preventing groove to prevent relative rotation between the insulating base and the slip ring. The internal rotor motor according to claim 5, characterized in that

7. Each conductive terminal has a slip ring connection portion, a hook portion, and a positioning portion connected between the slip ring connection portion and the hook portion, wherein the slip ring connection portion extends radially to electrically connect to the corresponding conductive ring, the hook portion is connected to the coil, the positioning portion is fixed within the insulating base, and the positioning portion and the slip ring connection portion together form an opening facing radially outward. The internal rotor motor according to claim 3, characterized in that

8. At least two pads are formed on the surface of the printed circuit board closest to the core, the number of the at least two pads is the same as the number of the at least two annular conductive traces, each of the at least two pads is connected to the corresponding annular conductive trace via the internal circuitry of the printed circuit board, and the slip ring connections of the at least two conductive terminals are fixedly connected to the corresponding pads. The internal rotor motor according to claim 7, characterized in that

9. The slip ring connections of the at least two conductive terminals are soldered to the corresponding pads, the coil is a three-phase coil, and the number of conductive rings, the number of at least two electrical connection terminals, and the number of at least two conductive terminals are all 3. The internal rotor motor according to claim 8, characterized in that

10. Reinforcing ribs are provided on the axial end face of the insulating base, and the circumferential position of the reinforcing ribs corresponds to the hook portion. The internal rotor motor according to claim 7, characterized in that

11. The insulating base has a projection at one end facing the core, the axial end face of the projection directly or indirectly contacts the core, and the projection of the projection onto a plane perpendicular to the shaft is smaller than the projection of the insulating base onto the surface, thereby reducing the axial contact area. The internal rotor motor according to claim 3, characterized in that

12. The at least two electrical connection terminals are arranged at intervals in the circumferential direction, and each electrical connection terminal comprises a power receiving portion arranged at an axial distance from the slip ring, and an elastic arm extending from the power receiving portion toward the slip ring, wherein the elastic arm elastically contacts the corresponding conductive ring, and an angle is formed between the extending direction of the elastic arm and the axial direction of the internal rotor motor, and the angle is greater than 0 degrees and less than 90 degrees. An internal rotor motor according to claim 1 or 2, characterized in that

13. The stator further comprises an end cover and at least two power connection elements for receiving power, the end cover being fixed to the axial end of the stator housing, the at least two power connection elements being fixed to the end cover, the at least two power connection elements being configured to receive alternating current, the number of the at least two power connection elements being the same as the number of the at least two electrical connection terminals, and each power connection element being connected to the corresponding electrical connection terminal to transmit alternating current to the electrical connection terminal, Alternatively, the at least two power connection elements are configured to receive direct current, and the internal rotor motor further integrates a conversion circuit which converts the direct current to alternating current and transmits the alternating current to the electrical connection terminals. An internal rotor motor according to claim 1 or 2, characterized in that

14. An internal rotor motor comprising a stator and a rotor rotatable relative to the stator, wherein the stator comprises a stator housing, at least one magnet disposed within the stator housing, and at least two electrical connection terminals, the rotor comprises a core, a shaft fixed to the core, a coil wound around the core, and a slip ring, the slip ring comprising at least two conductive rings arranged radially apart and electrically connected to the coil, the at least two electrical connection terminals arranged on one axial side of the slip ring, one end of each electrical connection terminal in contact with the corresponding conductive ring for electrical conductivity, and the other end of each electrical connection terminal receiving alternating current, The slip ring is plate-shaped, and the rotor further comprises an insulating base fitted onto the shaft and a sleeve firmly attached to the shaft. One end of the insulating base facing the sleeve has a projection, the axial end face of the projection abuts the sleeve directly or indirectly, and the slip ring is fitted onto the outer circumference of the projection and is axially positioned between the sleeve and the insulating base. An internal rotor motor characterized by the following features.

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