Coreless Motor

Abstract

The present invention discloses a coreless cup motor, which comprises a rotor assembly and a stator assembly, wherein the rotor assembly comprises a coil and a motor shaft, and the stator assembly comprises a housing and a first magnetic steel assembly, wherein the coil is located in the housing, and the first magnetic steel assembly is sleeved outside the housing, the motor shaft passes through the coil, and the motor shaft can drive the coil to rotate relative to the first magnetic steel assembly with the central axis of the motor shaft as the rotation axis, the polarity of the first magnetic steel assembly is arranged according to a Halbach array combination, and the magnetic force lines at both ends of the first magnetic steel assembly along the central axis of the motor shaft constrain the magnetic force lines of the first magnetic steel assembly in the middle of the central axis of the motor shaft within the effective area cut by the magnetic force lines of the coil; the present invention can effectively improve the performance of the coreless cup motor to meet the high-performance manufacturing requirements of the micro motor.

Description

Technical Field

[0001] The invention relates to the technical field of motor manufacturing, and in particular to a coreless cup motor. Background Art

[0002] In the existing hollow cup motor structure, the magnetization method of the magnetic steel is unidirectional magnetization, the direction of its magnetic pole is very single, and the strength of its magnetic field along the axial direction is uniformly distributed. However, the coil itself has magnetic lines of force cutting effective areas and invalid areas. Since the strength of the magnetic field strength of the magnetic steel along the axial direction is uniformly distributed, a considerable part of the magnetic lines of force of the magnetic steel acts on the invalid area, resulting in an excess magnetic field. The excess magnetic field cannot improve the efficiency of the motor, and the part of the magnetic steel that produces invalid magnetic lines of force undoubtedly increases the overall weight of the motor, which seriously restricts the lightweight of the hollow cup motor. And when it is necessary to increase the speed of the motor, it is necessary to increase the volume of the magnetic steel, which will not only increase the overall volume of the hollow cup motor, but also further increase the useless magnetic lines of force of the magnetic steel, and also increase the weight of the magnetic steel, which is easy to cause the instability of the hollow cup motor structure. Summary of the invention

[0003] The purpose of the present invention is to provide a coreless motor, which can effectively improve the performance of the coreless motor to meet the high performance manufacturing requirements of a micro motor.

[0004] In order to achieve the above purpose, the present invention discloses a hollow cup motor, which includes a rotor assembly and a stator assembly, the rotor assembly includes a coil and a motor shaft, the stator assembly includes a housing and a first magnetic steel assembly, the coil is located in the housing, the first magnetic steel assembly is sleeved outside the housing, the motor shaft passes through the coil, and the motor shaft can drive the coil to rotate relative to the first magnetic steel assembly with the central axis of the motor shaft as the rotation axis, the polarity of the first magnetic steel assembly is arranged according to a Halbach array combination, and the magnetic lines of force at both ends of the first magnetic steel assembly along the central axis of the motor shaft constrain the magnetic lines of force of the first magnetic steel assembly in the middle along the central axis of the motor shaft within the effective area cut by the magnetic lines of force of the coil.

[0005] Compared with the prior art, the first magnetic steel component of the present invention is sleeved outside the casing, and the motor shaft can drive the coil to rotate relative to the first magnetic steel component with the central axis of the motor shaft as the rotation axis. The rotation is achieved by changing the direction of the current flowing through the coil to cut the internal magnetic field of the first magnetic steel component. The polarity of the first magnetic steel component is arranged in a Halbach array combination, and the magnetic lines of force at both ends of the first magnetic steel component along the central axis of the motor shaft constrain the magnetic lines of force of the middle part of the first magnetic steel component along the central axis of the motor shaft within the effective area cut by the magnetic lines of force of the coil. The magnetic poles of the first magnetic steel component are arranged in a diversified manner by the Halbach array combination arrangement, so that the magnetic field strength of the first magnetic steel component is distributed axially and the magnetic field in the radial direction is concentrated and constrained within the effective area cut by the magnetic lines of force of the coil, effectively reducing the part of the magnetic lines of force of the first magnetic steel component falling into the invalid area cut by the magnetic lines of force of the coil, and effectively reducing the excess magnetic field rate, thereby achieving the performance of the hollow cup motor without increasing the weight of the magnetic steel and the outer diameter of the motor, so as to meet the high-performance manufacturing requirements of the micro motor.

[0006] Preferably, the first magnetic steel assembly includes a first constrained magnetic steel, a first effective magnetic steel and a second constrained magnetic steel connected in sequence, the first constrained magnetic steel and the second constrained magnetic steel are respectively arranged in a circular ring shape, the first effective magnetic steel is arranged in an annular cylindrical shape, the first constrained magnetic steel includes a first semi-circular ring magnetic steel and a second semi-circular ring magnetic steel, the first semi-circular ring magnetic steel and the second semi-circular ring magnetic steel are butt-connected to form the first constrained magnetic steel, the second constrained magnetic steel includes a third semi-circular ring magnetic steel and a fourth semi-circular ring magnetic steel, the third semi-circular ring magnetic steel and the fourth semi-circular ring magnetic steel are butt-connected to form the second constrained magnetic steel, the first semi-circular ring magnetic steel and the third semi-circular ring magnetic steel are respectively arranged at two ends of the radial upper half of the first effective magnetic steel along the central axis direction of the motor shaft, and the second semi-circular ring magnetic steel and the fourth semi-circular ring magnetic steel are respectively arranged at two ends of the radial lower half of the first effective magnetic steel along the central axis direction of the motor shaft.

[0007] Specifically, the polarity of the radial upper half and the radial lower half of the first effective magnetic steel along the central axis direction of the motor shaft are opposite;

[0008] The polarities of one end of the first semicircular ring magnetic steel and the third semicircular ring magnetic steel close to the radial upper half of the first effective magnetic steel along the central axis of the motor shaft are respectively consistent with the polarity of the radial upper half of the first effective magnetic steel along the central axis of the motor shaft;

[0009] The polarities of one end of the first semicircular ring magnetic steel and the third semicircular ring magnetic steel away from the radial upper half of the first effective magnetic steel along the central axis of the motor shaft are respectively opposite to the polarity of the radial upper half of the first effective magnetic steel along the central axis of the motor shaft;

[0010] The polarities of one end of the second semicircular ring magnetic steel and the fourth semicircular ring magnetic steel close to the radial lower half of the first effective magnetic steel along the central axis of the motor shaft are respectively consistent with the polarity of the radial lower half of the first effective magnetic steel along the central axis of the motor shaft;

[0011] The polarities of one end of the second semicircular ring magnetic steel and the fourth semicircular ring magnetic steel away from the radial lower half of the first effective magnetic steel along the central axis of the motor shaft are respectively opposite to the polarity of the radial lower half of the first effective magnetic steel along the central axis of the motor shaft.

[0012] Preferably, the stator assembly also includes a second magnetic steel assembly arranged in the coil, the second magnetic steel assembly includes a third constrained magnetic steel, a second effective magnetic steel and a fourth constrained magnetic steel, the third constrained magnetic steel and the fourth constrained magnetic steel are respectively arranged in a circular ring shape, the second effective magnetic steel is arranged in a ring-shaped cylindrical shape, the third constrained magnetic steel includes a fifth semicircular ring magnetic steel and a sixth semicircular ring magnetic steel, the fifth semicircular ring magnetic steel and the sixth semicircular ring magnetic steel are butt-connected to form the third constrained magnetic steel, the fourth constrained magnetic steel includes a seventh semicircular ring magnetic steel and an eighth semicircular ring magnetic steel, the seventh semicircular ring magnetic steel and the eighth semicircular ring magnetic steel are butt-connected to form the fourth constrained magnetic steel, the fifth semicircular ring magnetic steel and the seventh semicircular ring magnetic steel are respectively arranged at the two ends of the radial upper half of the second effective magnetic steel along the central axis direction of the motor shaft, the sixth semicircular ring magnetic steel and the eighth semicircular ring magnetic steel are respectively arranged at the two ends of the radial lower half of the second effective magnetic steel along the central axis direction of the motor shaft.

[0013] Specifically, the polarity of the radial upper half and the radial lower half of the second effective magnetic steel along the central axis of the motor shaft are opposite, and the polarity of the radial upper half of the second effective magnetic steel along the central axis of the motor shaft is opposite to that of the radial upper half of the first effective magnetic steel along the central axis of the motor shaft, and the polarity of the radial lower half of the second effective magnetic steel along the central axis of the motor shaft is opposite to that of the radial lower half of the first effective magnetic steel along the central axis of the motor shaft;

[0014] The polarities of one end of the fifth semicircular ring magnetic steel and the seventh semicircular ring magnetic steel close to the radial upper half of the second effective magnetic steel along the central axis of the motor shaft are respectively consistent with the polarity of the radial upper half of the second effective magnetic steel along the central axis of the motor shaft;

[0015] The polarities of one end of the fifth semicircular ring magnetic steel and the seventh semicircular ring magnetic steel away from the radial upper half of the second effective magnetic steel along the central axis of the motor shaft are respectively opposite to the polarity of the radial upper half of the second effective magnetic steel along the central axis of the motor shaft;

[0016] The polarities of one end of the sixth semicircular ring magnetic steel and the eighth semicircular ring magnetic steel close to the radial lower half of the second effective magnetic steel along the central axis of the motor shaft are respectively consistent with the polarity of the radial lower half of the second effective magnetic steel along the central axis of the motor shaft;

[0017] The polarities of one end of the sixth semicircular ring magnetic steel and the eighth semicircular ring magnetic steel away from the radial lower half of the second effective magnetic steel along the central axis of the motor shaft are respectively opposite to the polarity of the radial lower half of the second effective magnetic steel along the central axis of the motor shaft.

[0018] Preferably, the projections of the first effective magnetic steel and the second effective magnetic steel along a direction perpendicular to the central axis of the motor shaft completely fall within the effective area cut by the magnetic lines of force of the coil.

[0019] Preferably, the projections of the first effective magnetic steel and the second effective magnetic steel along a direction perpendicular to the central axis of the motor shaft completely fall within the projection of the coil along a direction perpendicular to the central axis of the motor shaft.

[0020] Preferably, the length of the first effective magnetic steel along the central axis of the motor shaft is equal to the length of the second effective magnetic steel along the central axis of the motor shaft.

[0021] Preferably, the lengths of the first effective magnetic steel and the second effective magnetic steel along the direction perpendicular to the central axis of the motor shaft are equal, and the lengths of the first effective magnetic steel and the second effective magnetic steel along the direction perpendicular to the central axis of the motor shaft are equal to the length of the coil along the direction perpendicular to the central axis of the motor shaft.

[0022] Preferably, the length of the first effective magnetic steel along the central axis of the motor shaft is greater than the length of the first constrained magnetic steel and the second constrained magnetic steel along the central axis of the motor shaft;

[0023] The length of the first constrained magnetic steel along the central axis of the motor shaft is equal to the length of the second constrained magnetic steel along the central axis of the motor shaft;

[0024] The length of the second effective magnetic steel along the central axis of the motor shaft is respectively greater than the length of the third constrained magnetic steel and the fourth constrained magnetic steel along the central axis of the motor shaft;

[0025] The length of the third constraining magnetic steel along the central axis direction of the motor shaft is equal to the length of the fourth constraining magnetic steel along the central axis direction of the motor shaft.

[0026] Preferably, the first magnetic steel assembly and the second magnetic steel assembly are arranged in an annular cylindrical shape, the first magnetic steel assembly includes a plurality of first magnetic steel monomers, and all the first magnetic steel monomers together form the first magnetic steel assembly along the radial direction of the motor shaft; the second magnetic steel assembly includes a plurality of second magnetic steel monomers, and all the second magnetic steel monomers together form the second magnetic steel assembly along the radial direction of the motor shaft.

[0027] Preferably, the stator assembly also includes an end cover for covering the open end of the casing, and the rotor assembly also includes a bearing, a bearing sleeve, a vibrator, a commutator assembly, a brush assembly and a wire. The bearing is fixedly connected to the casing, at least two of the bearings are sleeved on the motor shaft at intervals, the bearing sleeve is sleeved on the motor shaft through all the bearings, the first magnetic steel assembly is sleeved on the motor shaft through the bearing sleeve, one end of the motor shaft is rotatably connected to the end cover through the commutator assembly, and the other end can rotatably pass through the sealed end of the casing and connected to the vibrator, the vibrator is arranged in an eccentric structure, the coil is connected to the commutator assembly, the motor shaft rotates to drive the coil to rotate synchronously, the brush assembly is arranged in the end cover, the two wires pass through the end cover respectively, and one of the two wires is electrically connected to the positive end of the brush assembly, and the other is electrically connected to the negative end of the brush assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a structural schematic diagram of a coreless motor according to a first embodiment of the present invention;

[0029] Figure 2 yes Figure 1 Schematic diagram of the decomposition of

[0030] Figure 3 yes Figure 1 A cross-sectional view of

[0031] Figure 4 is an exploded schematic diagram of the first magnetic steel assembly of the present invention;

[0032] Figure 5 is a schematic diagram of the magnetic force line distribution of the first magnetic steel assembly of the present invention;

[0033] Figure 6 It is a schematic diagram of the position state of the first magnetic steel component and the coil of the present invention;

[0034] Figure 7 It is a polarity distribution diagram when the first magnetic steel component of the present invention is arranged in two sections along the central axis direction of the motor shaft;

[0035] Figure 8 It is a polarity distribution diagram when the first magnetic steel component of the present invention is arranged in four sections along the central axis direction of the motor shaft;

[0036] Fig. 9 It is a polarity distribution diagram when the first magnetic steel component of the present invention is arranged in five sections along the central axis direction of the motor shaft;

[0037] Fig.10 is an exploded schematic diagram of a coreless motor according to a second embodiment of the present invention;

[0038] Fig.11 is a cross-sectional view of a coreless motor according to a second embodiment of the present invention;

[0039] Fig.12 This is a schematic diagram of the decomposition of the second magnetic steel component of the present invention.

[0040] Fig.13 is a schematic diagram of the magnetic force line distribution of the second magnetic steel assembly of the present invention;

[0041] Fig.14 is a schematic diagram of the position status of the second magnetic steel component and the coil of the present invention;

[0042] Fig.15 is a schematic diagram of the positional relationship between the first magnetic steel component, the coil and the second magnetic steel component of the present invention;

[0043] Fig.16 yes Fig.15 A top view of

[0044] Fig.17 It is a schematic diagram of the state of the coil of the present invention under the combined action of the magnetic force lines of the first magnetic steel component and the second magnetic steel component;

[0045] Fig.18 It is a polarity distribution diagram when the second magnetic steel component of the present invention is arranged in two sections along the central axis direction of the motor shaft;

[0046] Fig.19 It is a polarity distribution diagram when the second magnetic steel assembly of the present invention is arranged in four sections along the central axis direction of the motor shaft;

[0047] Fig. 20 It is a polarity distribution diagram when the second magnetic steel component of the present invention is arranged in five sections along the central axis direction of the motor shaft. DETAILED DESCRIPTION

[0048] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0049] First embodiment

[0050] See also Figure 1-Figure 3As shown, the coreless motor of this embodiment includes a stator assembly and a rotor assembly, wherein the rotor assembly includes a coil 11 and a motor shaft 12, and the stator assembly includes a housing 21 and a first magnetic steel assembly 22, and the first magnetic steel assembly 22 is sleeved on the housing 21 by means such as bonding. The motor shaft 12 passes through the coil 11, and the motor shaft 12 can drive the coil 11 to rotate relative to the first magnetic steel assembly 22 with the central axis of the motor shaft 12 as the rotation axis, so as to realize the synchronous rotation of the motor shaft 12 and the coil 11. At this time, the coil 11 is located in the internal magnetic field of the first magnetic steel assembly 22, and the rotation is realized by changing the direction of the current flowing through the coil 11 to cut the internal magnetic field of the first magnetic steel assembly 22, and the speed adjustment and forward and reverse rotation adjustment of the coreless motor are realized by changing the direction and magnitude of the current flowing through the coil 11.

[0051] It can be understood that the coil 11 of the present embodiment is a coil 11 of a hexagonal annular column structure. Of course, in other embodiments, the coil 11 may be a coil 11 of other polygonal annular column structures, which is not limited here.

[0052] The polarity of the first magnetic steel component 22 is arranged in a Halbach array, and the magnetic force lines at both ends of the first magnetic steel component 22 along the central axis of the motor shaft 12 constrain the magnetic force lines in the middle of the first magnetic steel component 22 along the central axis of the motor shaft 12 within the effective area cut by the magnetic force lines of the coil 11. The Halbach array is a magnetic structure, which is an approximately ideal structure in engineering, and the goal is to use the least amount of magnets to generate the strongest magnetic field. In this embodiment, the Halbach array is used to concentrate most of the magnetic force lines inside the first magnetic steel component 22 within the effective area cut by the magnetic force lines of the coil 11, so as to reduce the magnetic force lines inside the first magnetic steel component 22 from falling into the invalid area cut by the magnetic force lines of the coil 11, so as to increase the magnetic force line efficiency of the first magnetic steel component 22 under the same volume, thereby effectively improving the performance of the hollow cup motor while slightly increasing the weight of the magnetic steel and the outer diameter of the motor, so as to meet the high-performance manufacturing requirements of the micro motor.

[0053] It should be noted that magnets generally refer to aluminum-nickel-cobalt alloys (Al Ni Co is the abbreviation of aluminum-nickel-cobalt in English). Magnets are made of several hard and strong metals, such as iron, aluminum, nickel, cobalt, etc., and sometimes copper, niobium, and tantalum. They are used to make super-hard permanent magnet alloys. Magnets can generate magnetic lines of force (also called magnetic fields). Magnetic lines of force are a virtual physical concept that refers to the field that transmits magnetic forces between real objects. The magnetic field has the radiation characteristics of waves and particles. There is a magnetic field around the magnet, and the interaction between magnets is mediated by the magnetic field, so the two magnets can interact without physical contact.

[0054] See also Figure 4 and Figure 5As shown, the first magnetic steel component 22 of this embodiment is arranged in an annular cylindrical shape, and the first magnetic steel component 22 is arranged in three sections along the central axis direction of the motor shaft 12. The first magnetic steel component 22 includes a first constrained magnetic steel 221, a first effective magnetic steel 222, and a second constrained magnetic steel 223 connected in sequence. The first constrained magnetic steel 221, the first effective magnetic steel 222, and the second constrained magnetic steel 223 are independently manufactured magnetic blocks, and are sequentially bonded to form the first magnetic steel component 22 of an integrated structure.

[0055] The first constrained magnetic steel 221 and the second constrained magnetic steel 223 are respectively arranged in a circular ring shape, and the first effective magnetic steel 222 is arranged in a ring cylindrical shape. The first constrained magnetic steel 221 includes a first semi-circular ring magnetic steel 2211 and a second semi-circular ring magnetic steel 2212. The first semi-circular ring magnetic steel 2211 and the second semi-circular ring magnetic steel 2212 are butt-jointed to form the first constrained magnetic steel 221. Accordingly, the first semi-circular ring magnetic steel 2211 and the second semi-circular ring magnetic steel 2212 are independently manufactured magnetic blocks, and are butt-jointed and bonded to form the first constrained magnetic steel 221 of an integrated structure.

[0056] The second constrained magnetic steel 223 includes a third semi-circular ring magnetic steel 2231 and a fourth semi-circular ring magnetic steel 2232, and the third semi-circular ring magnetic steel 2231 and the fourth semi-circular ring magnetic steel 2232 are butt-jointed to form the second constrained magnetic steel 223. Accordingly, the third semi-circular ring magnetic steel 2231 and the fourth semi-circular ring magnetic steel 2232 are independently manufactured magnetic blocks, and are butt-jointed and bonded to form the second constrained magnetic steel 223 of an integrated structure.

[0057] The first semicircular ring magnetic steel 2211 and the third semicircular ring magnetic steel 2231 are respectively arranged at the two ends of the radial upper half of the first effective magnetic steel 222 along the central axis direction of the motor shaft 12 by bonding, and the second semicircular ring magnetic steel 2212 and the fourth semicircular ring magnetic steel 2232 are respectively arranged at the two ends of the radial lower half of the first effective magnetic steel 222 along the central axis direction of the motor shaft 12 by bonding.

[0058] Specifically, the polarity of the radial upper half and the radial lower half of the first effective magnetic steel 222 along the central axis of the motor shaft 12 are opposite. In this embodiment, the polarity of the radial upper half of the first effective magnetic steel 222 along the central axis of the motor shaft 12 is N pole, and the polarity of the radial lower half is S pole.

[0059] At this time, the first effective magnetic steel 222 has an annular columnar structure. Figure 5 As shown, magnetic lines of force are generated radially downward along the motor shaft 12 , and the magnetic lines of force act on the effective area cut by the effective magnetic lines of force of the coil 11 , so that the rotation of the coil 11 is achieved by changing the current direction of the coil 11 .

[0060] The polarities of one end of the first semicircular magnetic steel 2211 and the third semicircular magnetic steel 2231 close to the radial upper half of the first effective magnetic steel 222 along the central axis of the motor shaft 12 are respectively consistent with the polarity of the radial upper half of the first effective magnetic steel 222 along the central axis of the motor shaft 12. In this embodiment, the polarities of one end of the first semicircular magnetic steel 2211 and the third semicircular magnetic steel 2231 close to the radial upper half of the first effective magnetic steel 222 along the central axis of the motor shaft 12 are both N poles.

[0061] The polarities of the ends of the first semicircular magnetic steel 2211 and the third semicircular magnetic steel 2231 which are away from the first effective magnetic steel 222 in the radial upper half along the central axis of the motor shaft 12 are opposite to the polarity of the first effective magnetic steel 222 in the radial upper half along the central axis of the motor shaft 12. In this embodiment, the polarities of the ends of the first semicircular magnetic steel 2211 and the third semicircular magnetic steel 2231 which are away from the first effective magnetic steel 222 in the radial upper half along the central axis of the motor shaft 12 are both S poles.

[0062] The polarities of one end of the second semicircular magnetic steel 2212 and the fourth semicircular magnetic steel 2232 close to the radial lower half of the first effective magnetic steel 222 along the central axis of the motor shaft 12 are respectively consistent with the polarity of the radial lower half of the first effective magnetic steel 222 along the central axis of the motor shaft 12. In this embodiment, the polarities of one end of the second semicircular magnetic steel 2212 and the fourth semicircular magnetic steel 2232 close to the radial lower half of the first effective magnetic steel 222 along the central axis of the motor shaft 12 are both S poles.

[0063] The polarities of one end of the second semicircular magnetic steel 2212 and the fourth semicircular magnetic steel 2232 away from the first effective magnetic steel 222 in the radial lower half of the central axis of the motor shaft 12 are opposite to the polarity of the first effective magnetic steel 222 in the radial lower half of the central axis of the motor shaft 12. In this embodiment, the polarities of one end of the second semicircular magnetic steel 2212 and the fourth semicircular magnetic steel 2232 away from the radial lower half of the first effective magnetic steel 222 in the radial lower half of the central axis of the motor shaft 12 are both N poles.

[0064] Through the above arrangement, the internal magnetic field line distribution of the annular column structure of the first magnetic steel component 22 is as follows: Figure 5As shown, since the magnetic lines of force have the characteristics of a closed loop and never intersecting, the magnetic lines of force generated inside the annular column of the first effective magnetic steel 222 can be constrained by the magnetic lines of force generated inside the annular column of the first constrained magnetic steel 221 and the second constrained magnetic steel 223, respectively, and are concentrated in the radial direction of the first effective magnetic steel 222. Since the coil 11 is generally adjacent to the first magnetic steel assembly 22, the relative positions of the first magnetic steel assembly 22 and the coil 11 are reasonably set, so that the area where the magnetic lines of force generated by the first effective magnetic steel 222 are concentratedly constrained can completely fall into the effective area cut by the magnetic lines of force of the coil 11, thereby theoretically achieving the maximum utilization rate of the magnetic lines of force of the first effective magnetic steel 222.

[0065] It is worth noting that in other preferred embodiments, the polarity of the radial upper half of the first effective magnetic steel 222 along the central axis of the motor shaft 12 is an S pole, and the polarity of the radial lower half of the first effective magnetic steel 222 along the central axis of the motor shaft 12 is an N pole. At this time, the polarities of each part of the first semicircular ring magnetic steel 2211, the second semicircular ring magnetic steel 2212, the third semicircular ring magnetic steel 2231 and the fourth semicircular ring magnetic steel 2232 need to be modified accordingly, which will not be elaborated here.

[0066] It should be noted that magnetization can magnetize magnetic materials or increase the magnetism of magnets with insufficient magnetism. Generally, the magnetic object to be magnetized is placed in the magnetic field formed by the coil 11 through which direct current passes to perform the magnetization operation. In actual operation, the first magnetic steel component 22 needs to have a large magnetism to meet the normal operation of the hollow cup motor of this embodiment. In addition, the magnetization method of all magnetic steels in this embodiment is unidirectional magnetization.

[0067] See also Figure 6 As shown, in order to achieve the maximum utilization rate of the magnetic lines of force of the first effective magnetic steel 222 in theory, the relative position of the first magnetic steel component 22 and the coil 11 is further optimized in this embodiment:

[0068] Specifically, the projection of the first effective magnetic steel 222 along the direction perpendicular to the central axis of the motor shaft 12 completely falls within the effective area cut by the magnetic lines of force of the coil 11, so that the area where the magnetic lines of force generated by the first effective magnetic steel 222 are concentratedly constrained completely falls within the effective area cut by the magnetic lines of force of the coil 11, thereby theoretically achieving the maximum utilization rate of the magnetic lines of force of the first effective magnetic steel 222.

[0069] Furthermore, the projection of the first effective magnetic steel 222 along the direction perpendicular to the central axis of the motor shaft 12 completely falls within the projection of the coil 11 along the direction perpendicular to the central axis of the motor shaft 12. It has been experimentally measured that the effective area cut by the magnetic lines of force of the coil 11 made by a specific winding method can be close to 100% in theory. At this time, the effective area cut by the magnetic lines of force of the coil 11 is the projection of the coil 11 along the direction perpendicular to the central axis of the motor shaft 12, and the projection of the first effective magnetic steel 222 along the direction perpendicular to the central axis of the motor shaft 12 completely falls within the projection of the coil 11 along the direction perpendicular to the central axis of the motor shaft 12. Specifically, Figure 6 It shows that when the length of the first effective magnetic steel 222 along the central axis of the motor shaft 12 is equal to the length of the coil 11 along the central axis of the motor shaft 12, the beneficial effect of maximizing the utilization rate of the effective area of ​​the magnetic line cutting can be obtained. At this time, the projections of the first constrained magnetic steel 221 and the second constrained magnetic steel 223 along the central axis of the motor shaft 12 are respectively located outside the projection of the coil 11 along the central axis of the motor shaft 12.

[0070] Furthermore, in order to further reduce the overall length of the coreless motor of this embodiment along the central axis of the motor shaft 12, the length of the first effective magnetic steel 222 along the central axis of the motor shaft 12 is respectively greater than the length of the first constrained magnetic steel 221 and the second constrained magnetic steel 223 along the central axis of the motor shaft 12. In fact, the proportion of the length of the first effective magnetic steel 222 along the central axis of the motor shaft 12 should be as large as possible. On the premise of ensuring that the first constrained magnetic steel 221 and the second constrained magnetic steel 223 can concentrate and constrain the magnetic lines of force generated by the first effective magnetic steel 222 in the radial direction of the first effective magnetic steel 222 and then diffuse outward, the length of the first constrained magnetic steel 221 and the second constrained magnetic steel 223 along the central axis of the motor shaft 12 should be reduced as much as possible to reduce the overall length of the coreless motor along the central axis of the motor shaft 12.

[0071] See also Figure 1-Figure 3 As shown, the stator assembly of this embodiment also includes an end cover 24 for covering the open end of the casing 21, and the rotor assembly also includes a bearing 13 and a bearing sleeve 14. The bearing 13 is fixedly connected to the casing 21, and at least two bearings 13 are sleeved on the motor shaft 12 at intervals. The bearing sleeve 14 is sleeved on the motor shaft 12 through all the bearings 13. The first magnetic steel assembly 22 is sleeved on the motor shaft 12 through the bearing sleeve 14. One end of the motor shaft 12 is rotatably connected to the end cover 24, and the other end can be rotatably passed through the sealed end of the casing 21.

[0072] Preferably, the rotor assembly further includes a vibrator 15, a commutator assembly 16, a brush assembly 17 and a wire 18. The vibrator 15 is arranged in an eccentric structure. The vibrator 15 is arranged at one end of the sealed end of the motor shaft 12 passing through the housing 21 by riveting. The motor shaft 12 is rotatably connected to the end cover 24 through the commutator assembly 16. The commutator assembly 16 is mounted on the end cover 24. The coil 11 is bonded and fixed on the commutator assembly 16. When the motor shaft 12 rotates, the coil 11, the commutator assembly 16 and the vibrator 15 are driven to rotate synchronously. The brush assembly 17 is arranged in the end cover 24 by embedding. The two wires 18 pass through the end cover 24 respectively, and one of the two wires 18 is electrically connected to the positive terminal of the brush assembly 17, and the other is electrically connected to the negative terminal of the brush assembly 17.

[0073] It is worth noting that the first magnetic steel component 22 of the present embodiment is arranged in three sections along the central axis direction of the motor shaft 12. In other preferred embodiments, the first magnetic steel component 22 is arranged in two sections, four sections, or five sections along the central axis direction of the motor shaft 12. Figure 7-Figure 9 Polarity distribution diagrams are given when the first magnetic steel component 22 is arranged in two sections, four sections, and five sections along the central axis of the motor shaft 12. On the premise of ensuring that the magnetic lines of force generated by the first magnetic steel component 22 can concentrate most of the magnetic lines of force of the first magnetic steel component 22 within the effective area cut by the magnetic lines of force of the coil 11, so as to reduce the magnetic lines of force of the first magnetic steel component 22 from falling into the invalid area cut by the magnetic lines of force of the coil 11, and to increase the magnetic line efficiency of the first magnetic steel component 22 under the same volume, the number of sections of the first magnetic steel component 22 along the central axis of the motor shaft 12 is not limited. In order to highlight the structure of the first magnetic steel component 22 being arranged in two sections, four sections, or five sections along the central axis of the motor shaft 12, Figure 7-Figure 9 In the figure, the thick line is the boundary between the magnets, and the dotted line is the internal hole of the magnet.

[0074] Furthermore, in other preferred embodiments, the first magnetic steel assembly 22 is arranged in an annular cylindrical shape, and the first magnetic steel assembly 22 includes a plurality of first magnetic steel monomers, all of which together form the first magnetic steel assembly 22 along the radial direction of the motor shaft 12, so as to produce an effect in which the magnetic lines of force at both ends of the first magnetic steel assembly 22 along the central axis direction of the motor shaft 12 constrain the magnetic lines of force of the first magnetic steel assembly 22 in the middle part along the central axis direction of the motor shaft 12 within the effective area cut by the magnetic lines of force of the coil 11.

[0075] Second embodiment

[0076] See also Figure 10-17As shown, this embodiment further enhances the magnetic force line density in the effective area cut by the magnetic force line of the coil 11 on the basis of the first embodiment. The stator assembly further includes a second magnetic steel assembly 23 disposed in the coil 11, and the second magnetic steel assembly 23 is used to further enhance the magnetic force line density in the effective area cut by the magnetic force line of the coil 11. The second magnetic steel assembly 23 is disposed in three sections corresponding to the first magnetic steel assembly 22.

[0077] Specifically, the second magnetic steel assembly 23 includes a third constrained magnetic steel 231, a second effective magnetic steel 232 and a fourth constrained magnetic steel 233 which are connected in sequence. The third constrained magnetic steel 231, the second effective magnetic steel 232 and the fourth constrained magnetic steel 233 are independently made magnetic blocks and are bonded in sequence to form a second magnetic steel assembly 23 with an integrated structure.

[0078] The third constrained magnet 231 and the fourth constrained magnet 233 are respectively arranged in a circular ring shape, the second effective magnet 232 is arranged in a ring cylindrical shape, the third constrained magnet 231 includes a fifth semi-circular ring magnet 2311 and a sixth semi-circular ring magnet 2312, the fifth semi-circular ring magnet 2311 and the sixth semi-circular ring magnet 2312 are butt-jointed to form the third constrained magnet 231, correspondingly, the fifth semi-circular ring magnet 2311 and the sixth semi-circular ring magnet 2312 are independently manufactured magnetic blocks, and are butt-jointed and bonded to form the third constrained magnet 231 of an integrated structure.

[0079] The fourth constrained magnetic steel 233 includes a seventh semicircular ring magnetic steel 2331 and an eighth semicircular ring magnetic steel 2332, and the seventh semicircular ring magnetic steel 2331 and the eighth semicircular ring magnetic steel 2332 are butt-jointed to form the fourth constrained magnetic steel 233. Accordingly, the seventh semicircular ring magnetic steel 2331 and the eighth semicircular ring magnetic steel 2332 are independently manufactured magnetic blocks, and are butt-jointed and bonded to form the fourth constrained magnetic steel 233 of an integrated structure.

[0080] The fifth semicircular ring magnetic steel 2311 and the seventh semicircular ring magnetic steel 2331 are respectively arranged at the two ends of the radial upper half of the second effective magnetic steel 232 along the central axis direction of the motor shaft 12 by bonding, and the sixth semicircular ring magnetic steel 2312 and the eighth semicircular ring magnetic steel 2332 are respectively arranged at the two ends of the radial lower half of the second effective magnetic steel 232 along the central axis direction of the motor shaft 12 by bonding.

[0081] Specifically, the polarity of the radial upper half of the second effective magnetic steel 232 along the central axis of the motor shaft 12 is opposite to that of the radial lower half, and the polarity of the radial upper half of the second effective magnetic steel 232 along the central axis of the motor shaft 12 is opposite to that of the radial upper half of the first effective magnetic steel 222 along the central axis of the motor shaft 12, and the polarity of the radial lower half of the second effective magnetic steel 232 along the central axis of the motor shaft 12 is opposite to that of the radial lower half of the first effective magnetic steel 222 along the central axis of the motor shaft 12. In this embodiment, corresponding to the first embodiment, the polarity of the radial upper half of the second effective magnetic steel 232 along the central axis of the motor shaft 12 is an S pole, and the polarity of the radial lower half of the second effective magnetic steel 232 along the central axis of the motor shaft 12 is an N pole.

[0082] The polarities of one end of the fifth semicircular magnetic steel 2311 and the seventh semicircular magnetic steel 2331 close to the second effective magnetic steel 232 along the central axis of the motor shaft 12 are respectively consistent with the polarity of the second effective magnetic steel 232 along the central axis of the motor shaft 12. In this embodiment, corresponding to the first embodiment, the polarities of one end of the fifth semicircular magnetic steel 2311 and the seventh semicircular magnetic steel 2331 close to the second effective magnetic steel 232 along the central axis of the motor shaft 12 are both S poles.

[0083] The polarities of one end of the fifth semicircular magnetic steel 2311 and the seventh semicircular magnetic steel 2331 away from the second effective magnetic steel 232 in the radial upper half of the central axis of the motor shaft 12 are opposite to the polarity of the second effective magnetic steel 232 in the radial upper half of the central axis of the motor shaft 12. In this embodiment, corresponding to the first embodiment, the polarities of one end of the fifth semicircular magnetic steel 2311 and the seventh semicircular magnetic steel 2331 away from the second effective magnetic steel 232 in the radial upper half of the central axis of the motor shaft 12 are both N poles.

[0084] The polarities of one end of the sixth semicircular magnetic steel 2312 and the eighth semicircular magnetic steel 2332 close to the second effective magnetic steel 232 along the central axis of the motor shaft 12 are respectively consistent with the polarity of the radial lower half of the second effective magnetic steel 232 along the central axis of the motor shaft 12. In this embodiment, corresponding to the first embodiment, the polarities of one end of the sixth semicircular magnetic steel 2312 and the eighth semicircular magnetic steel 2332 close to the radial lower half of the second effective magnetic steel 232 along the central axis of the motor shaft 12 are both N poles.

[0085] The polarity of one end of the sixth semicircular magnetic steel 2312 and the eighth semicircular magnetic steel 2332 away from the second effective magnetic steel 232 in the radial lower half of the central axis of the motor shaft 12 is opposite to the polarity of the second effective magnetic steel 232 in the radial lower half of the central axis of the motor shaft 12. In this embodiment, corresponding to the first embodiment, the magnetic properties of one end of the sixth semicircular magnetic steel 2312 and the eighth semicircular magnetic steel 2332 away from the second effective magnetic steel 232 in the radial lower half of the central axis of the motor shaft 12 are both S poles.

[0086] Through the above arrangement, the magnetic force lines distribution of the second magnetic steel assembly 23 is as follows: Fig.14 As shown, since the magnetic lines of force have the characteristics of a closed loop and never intersecting, the magnetic lines of force generated by the annular columnar exterior of the second effective magnetic steel 232 at this time can be constrained by the magnetic lines of force generated by the annular columnar exterior of the third constraining magnetic steel 231 and the fourth constraining magnetic steel 233, respectively, and then diffuse outward after being concentrated and constrained in the radial direction of the second effective magnetic steel 232. Since the coil 11 is generally adjacent to the second magnetic steel assembly 23, the relative positions of the second magnetic steel assembly 23 and the coil 11 are reasonably set, so that the area where the magnetic lines of force generated by the second effective magnetic steel 232 are concentrated and constrained can completely fall into the effective area cut by the magnetic lines of force of the coil 11, thereby theoretically achieving the maximum utilization rate of the magnetic lines of force of the second effective magnetic steel 232.

[0087] Without considering the influence of the first effective magnetic steel 222, the annular cylindrical outer portion of the second effective magnetic steel 232 is as follows Fig.13 The shown embodiment generates magnetic flux lines directed radially downward along the motor shaft 12 , which act on an effective area cut by the effective magnetic flux lines of the coil 11 .

[0088] Fig.15 and Fig.16 The positional relationship between the first magnetic steel component 22, the coil 11 and the second magnetic steel component 23 is shown respectively. At this time, the magnetic lines of force of the first effective magnetic steel 222 and the second effective magnetic steel 232 affect each other. Under the action of the second effective magnetic steel 232, the first effective magnetic steel 222 is superimposed with the magnetic lines of force of the second effective magnetic steel 232. The directions of the magnetic lines of force of the two are downward along the radial direction of the motor shaft 12, thereby obtaining a relatively Figure 6 or Fig.14 The more dense magnetic lines of force distribution based on the single magnetic steel component shown effectively increases the magnetic line density within the effective area cut by the effective magnetic lines of force of the coil 11, effectively improving the performance of the hollow cup motor of this embodiment.

[0089] Fig.17The diagram shows the distribution of magnetic lines of force on the coil 11 under the mutual influence of the first effective magnetic steel 222 and the second effective magnetic steel 232. Under the joint action of the first magnetic steel component 22 and the second magnetic steel component 23, the magnetic line density in the effective area cut by the magnetic lines of force of the coil 11 is greatly increased, which effectively improves the performance of the hollow cup motor of this embodiment.

[0090] Corresponding to the setting of the first effective magnetic steel 222, the projection of the second effective magnetic steel 232 along the direction perpendicular to the central axis of the motor shaft 12 completely falls within the effective area cut by the magnetic lines of force of the coil 11, so that the area where the magnetic lines of force generated by the second effective magnetic steel 232 are concentratedly constrained completely falls within the effective area cut by the magnetic lines of force of the coil 11, thereby theoretically achieving the maximum utilization rate of the magnetic lines of force of the second effective magnetic steel 232.

[0091] Furthermore, the projection of the second effective magnetic steel 232 along the direction perpendicular to the central axis of the motor shaft 12 completely falls within the projection of the coil 11 along the direction perpendicular to the central axis of the motor shaft 12. It has been experimentally measured that the effective area cut by the magnetic lines of force of the coil 11 made by a specific winding method can be close to 100%. At this time, the effective area cut by the magnetic lines of force of the coil 11 is the projection of the coil 11 along the direction perpendicular to the central axis of the motor shaft 12, and the projection of the second effective magnetic steel 232 along the direction perpendicular to the central axis of the motor shaft 12 completely falls within the projection of the coil 11 along the direction perpendicular to the central axis of the motor shaft 12. Specifically, Fig.14 and Fig.17 It shows that when the length of the second effective magnetic steel 232 along the central axis of the motor shaft 12 is equal to the length of the coil 11 along the central axis of the motor shaft 12, the beneficial effect of maximizing the utilization rate of the effective area of ​​the magnetic line cutting can be obtained. At this time, the projections of the third constrained magnetic steel 231 and the fourth constrained magnetic steel 233 along the central axis of the motor shaft 12 are respectively located outside the projection of the coil 11 along the central axis of the motor shaft 12.

[0092] Furthermore, in order to further reduce the overall length of the coreless motor of the present embodiment along the central axis direction of the motor shaft 12, the length of the second effective magnetic steel 232 along the central axis direction of the motor shaft 12 is respectively greater than the length of the third constrained magnetic steel 231 and the fourth constrained magnetic steel 233 along the central axis direction of the motor shaft 12. In fact, the proportion of the length of the second effective magnetic steel 232 along the central axis direction of the motor shaft 12 should be as large as possible. On the premise of ensuring that the third constrained magnetic steel 231 and the fourth constrained magnetic steel 233 can concentrate and constrain the magnetic lines of force generated by the second effective magnetic steel 232 in the radial direction of the second effective magnetic steel 232 and then diffuse outward, the length of the third constrained magnetic steel 231 and the fourth constrained magnetic steel 233 along the central axis direction of the motor shaft 12 should be reduced as much as possible to reduce the overall length of the coreless motor along the central axis direction of the motor shaft 12.

[0093] Specifically, the length of the first effective magnetic steel 222 along the central axis of the motor shaft 12 is equal to the length of the second effective magnetic steel 232 along the central axis of the motor shaft 12, and the lengths of the first constrained magnetic steel 221, the second constrained magnetic steel 223, the third constrained magnetic steel 231 and the fourth constrained magnetic steel 233 along the central axis of the motor shaft 12 are all equal, so as to optimize the size and weight of the hollow cup motor.

[0094] It is worth noting that, corresponding to the multi-stage arrangement of the first magnetic steel component 22 in other embodiments, the second magnetic steel component 23 can be arranged in two stages, four stages, or five stages along the central axis of the motor shaft 12. Figure 18-Figure 20 Polarity distribution diagrams are respectively given when the first magnetic steel assembly 22 and the second magnetic steel assembly 23 are arranged in two sections, four sections and five sections along the central axis direction of the motor shaft 12. On the premise of ensuring that the magnetic lines of force generated by the first magnetic steel assembly 22 and the second magnetic steel assembly 23 can concentrate and constrain most of the magnetic lines of force of the first magnetic steel assembly 22 and the second magnetic steel assembly 23 within the effective area cut by the magnetic lines of force of the coil 11, so as to reduce the magnetic lines of force of the first magnetic steel assembly 22 and the second magnetic steel assembly 23 from falling into the invalid area cut by the magnetic lines of force of the coil 11, so as to increase the magnetic line efficiency of the first magnetic steel assembly 22 and the second magnetic steel assembly 23 under the same volume, the number of sections of the first magnetic steel assembly 22 and the second magnetic steel assembly 23 along the central axis direction of the motor shaft 12 is not limited.

[0095] Furthermore, in other preferred embodiments, the second magnetic steel assembly 23 is arranged in an annular cylindrical shape, and the second magnetic steel assembly 23 includes a plurality of second magnetic steel monomers, all of which together form the second magnetic steel assembly 23 along the radial direction of the motor shaft 12, so as to produce an effect in which the magnetic lines of force at both ends of the second magnetic steel assembly 23 along the central axis direction of the motor shaft 12 constrain the magnetic lines of force of the second magnetic steel assembly 23 in the middle part along the central axis direction of the motor shaft 12 within the effective area cut by the magnetic lines of force of the coil 11.

[0096] Combination Figure 1-Figure 20The polarity of the first magnetic steel component 22 of the present invention is arranged in a Halbach array combination, and the magnetic lines of force at both ends of the first magnetic steel component 22 along the central axis direction of the motor shaft 12 constrain the magnetic lines of force of the first magnetic steel component 22 in the middle part of the central axis direction of the motor shaft 12 within the effective area cut by the magnetic lines of force of the coil 11. The magnetic poles of the first magnetic steel component 22 are arranged in a diversified manner by a Halbach array combination arrangement, so that the magnetic field strength of the first magnetic steel component 22 is distributed axially and the magnetic field in the radial direction is concentrated and constrained within the effective area cut by the magnetic lines of force of the coil 11, effectively reducing the portion of the magnetic lines of force of the first magnetic steel component 22 falling into the invalid area cut by the magnetic lines of force of the coil 11, and effectively reducing the excess magnetic field rate, thereby achieving the performance of the hollow cup motor without increasing the weight of the magnetic steel and the outer diameter of the motor, so as to meet the high-performance manufacturing requirements of the micro motor.

[0097] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A coreless motor, characterized in that: The invention comprises a rotor assembly and a stator assembly, wherein the rotor assembly comprises a coil and a motor shaft, and the stator assembly comprises a housing and a first magnetic steel assembly, wherein the coil is located in the housing, and the first magnetic steel assembly is sleeved outside the housing, and the motor shaft passes through the coil, and the motor shaft can drive the coil to rotate relative to the first magnetic steel assembly with the central axis of the motor shaft as the rotation axis, and the polarity of the first magnetic steel assembly is arranged according to a Halbach array combination, and the magnetic force lines at both ends of the first magnetic steel assembly along the central axis of the motor shaft constrain the magnetic force lines of the middle part of the first magnetic steel assembly along the central axis of the motor shaft within the effective area cut by the magnetic force lines of the coil; The first magnetic steel assembly includes a first constrained magnetic steel, a first effective magnetic steel, and a second constrained magnetic steel connected in sequence, the first constrained magnetic steel and the second constrained magnetic steel are respectively arranged in a circular ring shape, the first effective magnetic steel is arranged in a circular cylindrical shape, the first constrained magnetic steel includes a first semi-circular ring magnetic steel and a second semi-circular ring magnetic steel, the first semi-circular ring magnetic steel and the second semi-circular ring magnetic steel are butt-connected to form the first constrained magnetic steel, the second constrained magnetic steel includes a third semi-circular ring magnetic steel and a fourth semi-circular ring magnetic steel, the third semi-circular ring magnetic steel and the fourth semi-circular ring magnetic steel are butt-connected to form the second constrained magnetic steel, the first semi-circular ring magnetic steel and the third semi-circular ring magnetic steel are respectively arranged at both ends of the radial upper half of the first effective magnetic steel along the central axis direction of the motor shaft, and the second semi-circular ring magnetic steel and the fourth semi-circular ring magnetic steel are respectively arranged at both ends of the radial lower half of the first effective magnetic steel along the central axis direction of the motor shaft; The polarity of the radial upper half and the radial lower half of the first effective magnetic steel along the central axis of the motor shaft are opposite; The polarities of one end of the first semicircular ring magnetic steel and the third semicircular ring magnetic steel close to the radial upper half of the first effective magnetic steel along the central axis of the motor shaft are respectively consistent with the polarity of the radial upper half of the first effective magnetic steel along the central axis of the motor shaft; The polarities of one end of the first semicircular ring magnetic steel and the third semicircular ring magnetic steel away from the radial upper half of the first effective magnetic steel along the central axis of the motor shaft are respectively opposite to the polarity of the radial upper half of the first effective magnetic steel along the central axis of the motor shaft; The polarities of one end of the second semicircular ring magnetic steel and the fourth semicircular ring magnetic steel close to the radial lower half of the first effective magnetic steel along the central axis of the motor shaft are respectively consistent with the polarity of the radial lower half of the first effective magnetic steel along the central axis of the motor shaft; The polarities of one end of the second semicircular ring magnetic steel and the fourth semicircular ring magnetic steel away from the radial lower half of the first effective magnetic steel along the central axis of the motor shaft are respectively opposite to the polarity of the radial lower half of the first effective magnetic steel along the central axis of the motor shaft.

2. The coreless motor according to claim 1, characterized in that: The stator assembly also includes a second magnetic steel assembly arranged in the coil, the second magnetic steel assembly includes a third constrained magnetic steel, a second effective magnetic steel and a fourth constrained magnetic steel, the third constrained magnetic steel and the fourth constrained magnetic steel are respectively arranged in a circular ring shape, the second effective magnetic steel is arranged in a ring-shaped cylindrical shape, the third constrained magnetic steel includes a fifth semicircular ring magnetic steel and a sixth semicircular ring magnetic steel, the fifth semicircular ring magnetic steel and the sixth semicircular ring magnetic steel are butt-connected to form the third constrained magnetic steel, the fourth constrained magnetic steel includes a seventh semicircular ring magnetic steel and an eighth semicircular ring magnetic steel, the seventh semicircular ring magnetic steel and the eighth semicircular ring magnetic steel are butt-connected to form the fourth constrained magnetic steel, the fifth semicircular ring magnetic steel and the seventh semicircular ring magnetic steel are respectively arranged at the two ends of the radial upper half of the second effective magnetic steel along the central axis direction of the motor shaft, the sixth semicircular ring magnetic steel and the eighth semicircular ring magnetic steel are respectively arranged at the two ends of the radial lower half of the second effective magnetic steel along the central axis direction of the motor shaft.

3. The coreless motor according to claim 2, characterized in that: The polarity of the radial upper half and the radial lower half of the second effective magnetic steel along the central axis of the motor shaft are opposite, and the polarity of the radial upper half of the second effective magnetic steel along the central axis of the motor shaft is opposite to the polarity of the radial upper half of the first effective magnetic steel along the central axis of the motor shaft, and the polarity of the radial lower half of the second effective magnetic steel along the central axis of the motor shaft is opposite to the polarity of the radial lower half of the first effective magnetic steel along the central axis of the motor shaft; The polarities of one end of the fifth semicircular ring magnetic steel and the seventh semicircular ring magnetic steel close to the radial upper half of the second effective magnetic steel along the central axis of the motor shaft are respectively consistent with the polarity of the radial upper half of the second effective magnetic steel along the central axis of the motor shaft; The polarities of one end of the fifth semicircular ring magnetic steel and the seventh semicircular ring magnetic steel away from the radial upper half of the second effective magnetic steel along the central axis of the motor shaft are respectively opposite to the polarity of the radial upper half of the second effective magnetic steel along the central axis of the motor shaft; The polarities of one end of the sixth semicircular ring magnetic steel and the eighth semicircular ring magnetic steel close to the radial lower half of the second effective magnetic steel along the central axis of the motor shaft are respectively consistent with the polarity of the radial lower half of the second effective magnetic steel along the central axis of the motor shaft; The polarities of one end of the sixth semicircular ring magnetic steel and the eighth semicircular ring magnetic steel away from the radial lower half of the second effective magnetic steel along the central axis of the motor shaft are respectively opposite to the polarity of the radial lower half of the second effective magnetic steel along the central axis of the motor shaft.

4. The coreless motor according to claim 3, characterized in that: The projections of the first effective magnetic steel and the second effective magnetic steel along a direction perpendicular to the central axis of the motor shaft completely fall within the effective area cut by the magnetic lines of force of the coil.

5. The coreless motor according to claim 4, characterized in that: The length of the first effective magnetic steel along the central axis of the motor shaft is equal to the length of the second effective magnetic steel along the central axis of the motor shaft.

6. The coreless motor according to claim 2, characterized in that: The length of the first effective magnetic steel along the central axis of the motor shaft is respectively greater than the length of the first constrained magnetic steel and the second constrained magnetic steel along the central axis of the motor shaft; The length of the first constrained magnetic steel along the central axis of the motor shaft is equal to the length of the second constrained magnetic steel along the central axis of the motor shaft; The length of the second effective magnetic steel along the central axis of the motor shaft is respectively greater than the length of the third constrained magnetic steel and the fourth constrained magnetic steel along the central axis of the motor shaft; The length of the third constraining magnetic steel along the central axis of the motor shaft is equal to the length of the fourth constraining magnetic steel along the central axis of the motor shaft.

7. The coreless motor according to claim 2, characterized in that: The first magnetic steel assembly and the second magnetic steel assembly are arranged in an annular cylindrical shape. The first magnetic steel assembly includes a plurality of first magnetic steel monomers, and all the first magnetic steel monomers together form the first magnetic steel assembly along the radial direction of the motor shaft; the second magnetic steel assembly includes a plurality of second magnetic steel monomers, and all the second magnetic steel monomers together form the second magnetic steel assembly along the radial direction of the motor shaft.

8. The coreless motor according to claim 1, characterized in that: The stator assembly also includes an end cover for covering the open end of the casing, and the rotor assembly also includes a bearing, a bearing sleeve, a vibrator, a commutator assembly, a brush assembly and a wire. The bearing is fixedly connected to the casing, at least two of the bearings are sleeved on the motor shaft at intervals, the bearing sleeve is sleeved on the motor shaft through all the bearings, the first magnetic steel assembly is sleeved on the motor shaft through the bearing sleeve, one end of the motor shaft is rotatably connected to the end cover through the commutator assembly, and the other end can rotatably pass through the sealed end of the casing and connect to the vibrator, the vibrator is arranged in an eccentric structure, the coil is connected to the commutator assembly, the motor shaft rotates to drive the coil to rotate synchronously, the brush assembly is arranged in the end cover, the two wires pass through the end cover respectively, and one of the two wires is electrically connected to the positive end of the brush assembly, and the other is electrically connected to the negative end of the brush assembly.

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