Internal rotor motor
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- JOHNSON ELECTRIC INTERNATIONAL AG
- Filing Date
- 2024-12-27
- Publication Date
- 2026-07-29
AI Technical Summary
The axial length of internal rotor motors is limited by the conductive rings, which occupy a large axial space, leading to performance degradation when the motor size needs to be constrained.
The internal rotor motor design features radially spaced conductive rings, allowing the slip ring to have smaller axial dimensions while maintaining larger axial dimensions for the rotor core, thus enhancing motor performance.
This design enables the motor to maintain performance while reducing its axial length, making it suitable for applications requiring compact motor sizes.
Smart Images
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Abstract
Description
[Technical field]
[0001] This application relates to the field of motor technology, and in particular to internal rotor motors. [Background technology]
[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, the motor can be divided into two main types: internal rotor motor and external rotor motor. The stator of the internal rotor motor includes a stator housing, a magnet fixed to the inner wall of the stator housing, and a plurality of brushes. The rotor includes a core, a coil wound around the core, and a slip ring that rotates with the rotating shaft. The slip ring is substantially cylindrical and includes a plurality of conductive rings that are axially spaced apart and electrically connected to the coil. During the rotation of the rotor, an external alternating current is transmitted to the coil through the plurality of brushes and conductive rings. The motor transmits the alternating current to the coil through the brushes and slip rings without the need for a conventional commutator for mechanical commutation, effectively improving the 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. If the axial length of the motor needs to be limited to 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, an internal rotor motor is provided that takes into consideration motor performance and motor size.
[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 radially spaced conductive rings electrically connected to the coil, the at least two electrical connection terminals disposed on one axial side of the slip ring, one end of each electrical connection terminal in contact with and electrically conductive with a corresponding conductive ring, and the other end of each electrical connection terminal configured to receive alternating current.
[0006] Compared with the prior art, in the internal rotor motor of the present application, the conductive rings are radially spaced apart, so that the slip rings have a relatively small axial dimension and the rotor core can maintain a relatively large axial dimension to enhance motor performance. [Brief description of the drawings]
[0007] [Figure 1] FIG. 2 is a schematic structural diagram of an internal rotor motor in an embodiment of the present application; [Diagram 2] FIG. 2 is an exploded view of the internal rotor motor shown in FIG. 1. [Diagram 3] FIG. 3 is a further exploded view of the internal rotor motor shown in FIG. [Figure 4] FIG. 4 is an exploded front view of the internal rotor motor shown in FIG. [Diagram 5] FIG. 2 is a cross-sectional view of the internal rotor motor shown in FIG. [Figure 6] FIG. 2 is a top view of a slip ring of the internal rotor motor shown in FIG. 1. [Figure 7] 2 is a schematic structural diagram of an insulating base and a conductive terminal of the internal rotor motor shown in FIG. 1. [Figure 8] FIG. 2 is a schematic structural diagram of the slip ring, electrical connection terminals and power connection elements of the internal rotor motor shown in FIG. 1. [Figure 9] FIG. 2 is a schematic structural diagram of a resilient arm of the internal rotor motor shown in FIG. 1 according to another embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0008] In order to facilitate the understanding of the present application, a more comprehensive description is provided below with reference to the accompanying drawings, which exemplarily illustrate one or more embodiments of the present application, so that the understanding of the technical solutions disclosed in the present application will be more thorough and accurate. However, it should be understood that the present application can be embodied in various forms and is not limited to the embodiments described below.
[0009] In the accompanying drawings of 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 "upper", "lower", "left" and "right" are used to indicate a positional or directional relationship based on the direction or position shown in the drawings. These terms are merely for convenience in describing this application and for the sake of simplicity of description, and do not indicate or imply that the devices or elements referred to have a particular orientation or must be configured and operated in a particular orientation. Thus, the terms used to describe positional relationships in the drawings are merely for illustration and should not be understood as limiting the present invention. The specific meanings of the aforementioned terms can be understood by those skilled in the art based on the particular circumstances.
[0010] The present application provides an internal rotor motor, and a specific embodiment of the present application is described in Figures 1 to 3. 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 an 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 to form north and south poles in the circumferential direction of the stator housing 12. The at least one magnet 14 may also 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 may also be a permanent magnet made of a strong magnetic material such as neodymium iron boron, or the magnet 14 may be an electromagnet that generates a stable magnetic field when energized. Preferably, the at least two electrical connection terminals 15 are spaced apart along the circumferential direction.
[0012] 4-5, the rotor 30 includes a shaft 31, a core 32, a coil 34 wound around the core 32, and a slip ring 36 sleeved on 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 may be made of stacked silicon steel sheets including a yoke portion sleeved on the shaft 31 and a plurality of teeth extending radially outward from the yoke portion. The shaft 31 may 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 apart to form a winding slot for the coil 34.
[0013] Referring to FIG. 6, the slip ring 36 includes at least two conductive rings 361 spaced apart from each other in the radial direction. 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 (first side) surface of the printed circuit board facing the electrical connection terminal 15. The at least two annular conductive traces form the 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 a corresponding conductive trace via an internal circuit in the printed circuit board. More preferably, the at least two pads are formed on the other (second side) surface of the printed circuit board and are located close to the shaft 31.
[0014] The electrical connection terminal 15 is disposed on one axial side of the slip ring 36. One end of the electrical connection terminal 15 is in electrical conductive 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 may be a multi-phase coil or a single-phase coil. When the coil 34 is a multi-phase coil, the number of the conductive rings 361 and the number of the electrical connection terminals 15 are both equal to or greater than the number of phases of the multi-phase coil, and each phase coil is electrically connected to one of the conductive rings 361, so that each phase coil can be conductive with AC current through one conductive ring and one electrical connection terminal 15 in contact with the conductive ring. Preferably, the number of the conductive rings 361 and the number of the electrical connection terminals 15 are equal to the number of phases of the multi-phase coil. When the coil 34 is a single-phase coil, the number of the conductive rings 361 and the number of the electrical connection terminals 15 are both two. The two conductive rings 361 are respectively connected to the front end and the rear end of the single-phase coil, and each end of the single-phase coil can be conductive with AC 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 star-connected (Y-connected) or delta-connected (Δ-connected), which are commonly used in three-phase motors. Each phase coil 34 can be composed of multiple coils connected in parallel or series, and therefore the AC current is a three-phase AC current. In the following, the internal rotor motor of the present application will be described by taking the three-phase coil, the three conductive rings 361, and the three electrical connection terminals 15 as examples. When the internal rotor motor starts, a three-phase AC current is conducted to the three-phase coils of the rotor through the three electrical connection terminals 15 and the three conductive rings 361. The AC current can be a sine wave, a square wave, etc., and the current of each phase coil can form a phase difference of 120 degrees, which generates a rotating magnetic field to rotate the rotor 30 continuously relative to the stator 10. During the rotation of the rotor 30, the electrical connection terminals 15 and the conductive rings 361 maintain a conductive state and perform the function of electrical connection.
[0017] It should be understood that the coils of the rotor 30 can be configured with any number of phases, such as four phases, five phases, etc. In this case, the number of conductive rings 361 and the number of 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 AC current. In the embodiment of the present application, only a three-phase coil is taken as an example, but is not limited thereto.
[0018] Compared to the prior art, since at least two conductive rings 361 are radially spaced apart, the slip ring 36 has a relatively small axial dimension, while the core 32 of the rotor 30 maintains a relatively large axial dimension, thereby improving the performance of the motor. The internal rotor motor of the present application is particularly suited for small outer diameter motors (eg, motors having 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 sleeve-connected to 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 onto the conductive terminals 39. At least a portion of the insulating base 38 is disposed on a side of the slip ring 36 close 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, which is tightly attached to the shaft 31. Preferably, the sleeve 41 is a metal sleeve. The slip ring 36 is disposed axially between the sleeve 41 and the insulating base 38.
[0021] Preferably, one end of the insulating base 38 facing the first sleeve 41 has a first protrusion 380. The axial end face of the first protrusion 380 abuts the first sleeve 41, so that the first sleeve 41 can limit the axial position of the insulating base 38. The first protrusion 380 can abut the first sleeve 41 directly, or can abut the first sleeve 41 indirectly via an element such as a washer. The projection of the first protrusion 380 on a plane perpendicular to the shaft 31 is smaller than the projection of the insulating base 38 on the same plane, which reduces the area of axial abutment against the first sleeve 41. Since the first protrusion 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 protrusion 380 is a ring-shaped protrusion. In other embodiments, the first protrusion 380 can also be at least one arcuate protrusion or at least two circumferentially spaced protrusions. The slip ring 36 is sleeve-connected onto the outer periphery of the first protrusion 380 and is disposed axially between the first sleeve 41 and the insulating base 38 .
[0022] Preferably, the first protrusion 380 is formed with an anti-rotation protrusion 381 on its radially outer side, and the slip ring 36 is formed with a groove 363 on its radially inner side that engages with the anti-rotation protrusion 381 to prevent relative rotation between the insulating base 38 and the slip ring 36. It can also be understood that the first protrusion 380 can be formed with an anti-rotation groove on its radially outer side, while the slip ring 36 is formed with a protrusion on its radially inner side that engages with the anti-rotation groove to prevent relative rotation between the insulating base 38 and the slip ring 36.
[0023] Preferably, one end of the insulating base 38 facing the core 32 has a second protrusion 383. The axial end face of the second protrusion 383 abuts the core 32. The second protrusion 383 can abut directly on the core 32 or indirectly on the core 43 via an element such as a second sleeve 43 and / or a washer. The projection of the second protrusion 383 on a plane perpendicular to the shaft 31 is smaller than the projection of the insulating base 38 on the same plane, reducing the area of axial abutment on the core. Since the second protrusion 383 has a smaller axial end face, the flatness can be better controlled and guaranteed, allowing for a better axial position. In this embodiment, the second protrusion 383 is an annular protrusion. In other embodiments, the second protrusion 383 can also be at least one arcuate protrusion or at least two protrusions spaced apart in the circumferential direction.
[0024] 5, each conductive terminal 39 includes a slip ring connection portion 391, a hook portion 393, and a positioning portion 395 connected between the slip ring connection portion 391 and the hook portion 393. The hook portion 393 is connected to the coil 34. The positioning portion 395 is fixed in the insulating base 38. Preferably, the positioning portion 395 can be fixed in the insulating base 38 by injection molding. It can be understood that the positioning portion 395 can also be fixed in the insulating base 38 by insertion or other means. The slip ring connection portions 391 of the conductive terminals 39 are electrically connected to the corresponding conductive rings 361, respectively. In this embodiment, the slip ring connection portions 391 extend in the radial direction. The positioning portion 395 and the slip ring connection portion 391 collectively form an opening facing outward along the radial direction. The slip ring connection portion 391 is soldered to a pad on a printed circuit board. The hook portion 393 has a slot communicating with the opening. The open ends of the slots face axially outward from the core 32. Preferably, depending on the needs of the winding, the hook portion 393 of each conductive terminal 39 may have one or more hooks for connecting 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 the reinforcing rib 385 is close to the hook portion 393 so that this portion of the insulating base 38 has higher strength and prevents this portion from being damaged when the conductive terminal 39 is bent to form the hook portion 393.
[0026] Preferably, referring to FIG. 8, each electrical connection terminal 15 includes a power receiving portion 151 spaced apart from the slip ring 36 in the axial direction, and an elastic arm 153 extending from the power receiving portion 151 toward the slip ring 36. The elastic arm 153 elastically abuts against the corresponding conductive ring 361 to prevent a gap between the electrical connection terminal 15 and the conductive ring 361, so as to ensure good contact between the electrical connection terminal 15 and the conductive ring 361 and to avoid non-continuity 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 greater than 35 degrees and less than 55 degrees.
[0027] Preferably, a bulge 154 is formed at the end of the elastic arm 153, and the bulge 154 abuts against the corresponding conductive ring 361 and is conductive therewith. The surface of the bulge 154 is preferably, but not limited to, spherical or elliptical. The contact between the bulge 154 and the conductive ring 361 can reduce the contact area, thereby reducing wear, and allows the electrical connection terminal 15 to smoothly contact the conductive ring 361 when 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 can abut against the conductive ring 361 via a carbon brush.
[0028] 9, in another embodiment, the electrical connection terminal 15 includes two elastic arms 155 extending from the power receiving portion 151 toward the conductive ring. The two elastic arms 155 are disposed in the counterclockwise and clockwise directions of the power receiving portion 151, respectively. The two elastic arms 155 abut against the same conductive ring 361, thereby ensuring better conductivity 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, but it can be understood that the cap 121 can also be formed independently of the stator housing 12 and then assembled into one unit. The stator 10 can further include a cover plate 18 fixed to the end cover 17. Preferably, the cap 121 is formed with a bearing seat for mounting the bearing 19, and the end cover 17 or the cover plate 18 also has a bearing seat for mounting the bearing 19. Both ends of the shaft 31 are inserted into one bearing 19 respectively, and the bearing 19 provides 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 periphery 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 fixing the end cover 17, the cover plate 18 and the stator housing 12 together.
[0031] Preferably, the internal rotor motor of the present application also includes at least two power connection elements 16 for receiving electric power. The power connection elements 16 are fixed to the end cover 17. Specifically, referring to FIG. 9, the power connection elements 16 have an axially extending portion 161 and a radially extending portion 163. The axially extending portion 161 protrudes on a side of the end cover 17 away from the slip ring 36. The radially extending portion 163 is located on a side of the end cover 17 closer to the slip ring 36 for axial positioning of the power connection elements 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 the power connection elements 16 extends outside the end cover 17 for receiving AC current, and the other end is connected to a corresponding electrical connection terminal 15 for transmitting the AC 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 another embodiment, the power connection element 16 can also be used to receive direct current, in which case the internal rotor motor further integrates a DC (direct current) to AC (alternating current) conversion circuit configured to convert the direct current to an alternating current and then transmit the alternating current to the electrical connection terminal 15.
[0034] The present application is not limited to the above embodiments. Based on the creative spirit of the present application, other modifications may be made by those skilled in the art, and all such modifications made according to the creative spirit of the present application should fall within the scope of protection set forth in the claims of this application. [Explanation of symbols]
[0035] 10 Stator 12 Stator housing 14. Magnet 15 Electrical connection terminal 16 Power Connection Elements 17 End cover 18 Cover plate 19 Bearings 30 rotors 31 Shaft 32 cores 34 Coil 36 Slip Ring 38 Insulating Base 39 Conductive terminal 41 First Sleeve 43 Second Sleeve 121 Cap 123 Notch 151 Power receiving unit 153(155) Elastic arm 154 Bulge 161 Axial extending part 163 Radial extension 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 protrusion 385 Reinforcement rib 391 Slip ring connection 393 Hook part 395 Positioning part
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.