Four-side rotor electromagnetic drive with fan-cooling centrifugal structure

Abstract

The four-side rotor electromagnetic drive comprises a stator and a rotor, the stator is composed of a stator support, a stator iron core and a coil winding, and radial teeth and axial teeth are arranged on the inner periphery, the outer periphery, the front end and the rear end of the stator iron core; the rotor comprises a rotor shell and four magnetic pole arrays, the rotor shell is provided with centrifugal flow channels, and the centrifugal flow channels are formed by radial fins at intervals and generate centrifugal airflow when rotating along with the rotor; meanwhile, two heat dissipation hole communication paths are designed, namely a first heat dissipation hole (a front cover plate), a second heat dissipation hole (a first axial magnetic pole) and a first axial air gap which are communicated in sequence, and a third heat dissipation hole (a rear cover plate), a fourth heat dissipation hole (a second axial magnetic pole) and a second axial air gap which are communicated in sequence; the rotor rotates to drive airflow, internal heat of four-side electromagnetic drive can be directly and effectively guided out through heat dissipation paths at the two axial ends of the rotor, an additional power source is not needed, efficient heat dissipation is achieved, and the complexity of the system is not increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and particularly relates to a four-sided rotor electromagnetic drive with a self-fan-cooled centrifugal structure. Background Art

[0002] The axial-radial flux motor is an electromagnetic drive device that comprehensively utilizes axial flux and radial flux, and its structure can be composed of 3 or 4 rotors. Among them, the axial-radial flux electromagnetic drive with 4 rotors has significant torque density advantages, but at the same time also faces severe heat dissipation challenges: the permanent magnets of the inner rotor generate heat due to eddy current losses, and it is difficult to timely dissipate the heat generated by the hysteresis losses of the stator core and the copper losses of the windings. The main reason is that the inner rotor of the four-sided motor and the inner side of the annular winding are tightly wrapped by the four-sided rotor, forming a closed structure, and the high thermal resistance characteristics of the air gap itself further hinder the heat transfer. Therefore, how to effectively improve the heat dissipation capacity of the four-sided motor has become a key technical problem in improving its power density.

[0003] Currently, the heat dissipation technologies for such motors mainly include the following three solutions:

[0004] (1) Housing heat dissipation fins: By adding fins to the motor housing to increase the heat dissipation area;

[0005] (2) Internal heat conduction filling: Using winding potting or filling thermal grease between component contact surfaces to reduce the contact thermal resistance between the inner rotor, winding, iron core and housing;

[0006] (3) Liquid cooling system: Such as spiral water channels in the housing or direct oil cooling in the stator slots, using a circulating cooling medium to forcibly dissipate heat.

[0007] However, the above existing technologies have the following inherent defects:

[0008] (1) The addition of stator fins will cause an increase in the radial or axial dimensions of the motor because the heat dissipation effect of the stator fins is restricted by its own heat dissipation area, and the larger its surface area, the larger the motor size;

[0009] (2) The use of winding potting or thermal filling materials significantly increases the overall mass of the system, and the process is complex and the cost is high;

[0010] (3) The water cooling or oil cooling scheme requires additional components such as a coolant circulation pump and a heat exchanger, which not only increases the volume and mass of the system, but also introduces leakage risks and maintenance costs.

[0011] In summary, the existing heat dissipation technologies are difficult to solve the efficient heat dissipation problem of the four-sided motor under the premise of considering compactness, lightweight and reliability, and there is an urgent need for an innovative heat dissipation structure design. Summary of the Invention

[0012] The problem to be solved by the present invention is to provide a four-sided rotor electromagnetic drive with a self-fanning centrifugal structure, which can significantly improve the heat dissipation efficiency of the four-sided rotor electromagnetic drive without an external cooling system, while maintaining high power density and compactness, providing an innovative solution for the thermal management of high torque density motors.

[0013] To solve the above technical problems, the present invention provides a four-sided rotor electromagnetic drive with a self-fanning centrifugal structure, which includes a stator and a rotor;

[0014] The stator includes a stator bracket, a stator core and a coil winding; the stator bracket and the stator core are axially spaced apart and fixedly connected to the stator core; the stator bracket is fixedly connected with a central shaft, the stator core is annular, the central shaft is axially inserted into the middle of the stator core and is coaxial with the stator core; the outer periphery of the stator core is provided with a plurality of first radial teeth evenly distributed along its circumferential direction, the inner periphery of the stator core is provided with a plurality of second radial teeth evenly distributed along its circumferential direction, the front end of the stator core is provided with a plurality of first axial teeth evenly distributed along its circumferential direction, and the rear end of the stator core is provided with a plurality of second axial teeth evenly distributed along its circumferential direction; the coil winding is rectangularly wound around the first radial teeth, the second radial teeth, the first axial teeth and the second axial teeth;

[0015] The rotor includes a rotor housing, a first radial pole array, a second radial pole array, a first axial pole array and a second axial pole array; the rotor housing is provided with a rotating shell, a rotating shaft sleeve, a front cover plate and a rear cover plate, the front end of the rotating shell is fixedly connected to the front cover plate, the rotating shaft sleeve is rotatably connected to the central shaft through a bearing, the front end of the rotating shaft sleeve is fixedly connected to the front cover plate, the rear end of the rotating shaft sleeve is fixedly connected to the rear cover plate, and the rear cover plate is arranged between the stator bracket and the stator core; the first radial pole array is annularly arranged on the inner periphery of the rotating shell, the second radial pole array is annularly arranged on the outer periphery of the rotating shaft sleeve, the first axial pole array is annularly arranged on the inner side of the front cover plate, and the second axial pole array is annularly arranged on the inner side of the rear cover plate; the first radial pole array and the first radial teeth are spaced apart to form a first radial air gap, the second radial pole array and the second radial teeth are spaced apart to form a second radial air gap, the first axial pole array and the first axial teeth are spaced apart to form a first axial air gap, and the second axial pole array and the second axial teeth are spaced apart to form a second axial air gap;

[0016] The rotor housing is provided with a heat dissipation flow channel, which includes a first centrifugal flow channel arranged on the side of the front cover plate away from the first axial magnetic pole array and a second centrifugal flow channel arranged on the side of the rear cover plate away from the second axial magnetic pole array; the first centrifugal flow channel is formed by a plurality of first fins extending radially and evenly distributed along the circumferential direction of the front cover plate; the second centrifugal flow channel is formed by a plurality of second fins extending radially and evenly distributed along the circumferential direction of the rear cover plate; a plurality of first heat dissipation holes corresponding to the positions of the permanent magnets in the first axial magnetic pole array are arranged in the first centrifugal flow channel; second heat dissipation holes communicating the first heat dissipation holes and the first axial air gap are arranged on the permanent magnets in the first axial magnetic pole array; a plurality of third heat dissipation holes corresponding to the positions of the permanent magnets in the second axial magnetic pole array are arranged in the second centrifugal flow channel; fourth heat dissipation holes communicating the third heat dissipation holes and the second axial air gap are arranged on the permanent magnets in the second axial magnetic pole array.

[0017] As a preferred solution of the present invention, a fifth heat dissipation hole communicating with the inner cavity of the rotor housing is arranged on the outer diameter side of the front cover plate.

[0018] As a preferred solution of the present invention, a first axial flow channel axially penetrating the entire tooth part is arranged on the tooth part of the first radial tooth.

[0019] As a preferred solution of the present invention, the stator bracket and the stator core are fixedly connected through heat conduction columns.

[0020] As a preferred solution of the present invention, one end of the heat conduction column is fixedly inserted into the first axial flow channel, and the other end of the heat conduction column is fixedly inserted into the stator bracket; the number of the heat conduction columns is half of the number of the first axial flow channels, and one heat conduction column is inserted every other first axial flow channel.

[0021] As a preferred solution of the present invention, a second axial flow channel axially penetrating the entire tooth part is arranged on the tooth part of the second radial tooth.

[0022] As a preferred solution of the present invention, third axial flow channels axially penetrating the entire stator core are arranged on both the first axial tooth and the second axial tooth.

[0023] As a preferred solution of the present invention, a plurality of the third axial flow channels are arranged at radial intervals along the first axial tooth and the second axial tooth.

[0024] As a preferred solution of the present invention, the heat dissipation flow channel further includes a fourth axial flow channel axially penetrating the inner diameter side of the front cover plate, the rotating shaft sleeve and the inner diameter side of the rear cover plate in sequence.

[0025] As a preferred embodiment of the present invention, the pole pitches of the first radial magnetic pole array, the second radial magnetic pole array, the first axial magnetic pole array and the second axial magnetic pole array are the same and the permanent magnets are aligned, and the pole pitch is: τ=360° / 2P, where p is the number of pole pairs; the first radial magnetic pole array, the second radial magnetic pole array, the first axial magnetic pole array and the second axial magnetic pole array are all based on the center line of the permanent magnet corresponding to the same central angle and with the magnetization direction facing the air gap or away from the air gap, and the magnetization direction of the permanent magnet passing through each pole pitch alternates between away from the air gap and toward the air gap.

[0026] Compared with the prior art, the four-sided rotor electromagnetic drive with a self-fan cooling centrifugal structure according to the embodiment of the present invention has the following beneficial effects:

[0027] (1) In the embodiment of the present invention, the first radial rotor (i.e., the first radial magnetic pole array), the second radial rotor (i.e., the second radial magnetic pole array), the first axial rotor (i.e., the first axial magnetic pole array), and the second axial rotor (i.e., the second axial magnetic pole array) respectively form an air gap magnetic field in the radial and axial directions of the stator. When three three-phase sinusoidal currents with a difference of 120 degrees in electrical angle are passed through the coil windings surrounding the first radial teeth, the second radial teeth, the first axial teeth, and the second axial teeth, the air gap magnetic field formed by the rotor interacts with the symmetrical current in the coil windings to generate a rotating magnetic motive force, driving the first radial rotor, the second radial rotor, the first axial rotor, and the second axial rotor to rotate synchronously to output torque. This four-rotor design allows the coil windings at the ends of the motor to be effectively utilized. Without increasing the volume of the system, it can effectively increase the air gap area of ​​the motor for electromechanical energy conversion (generating torque), thereby increasing the torque density of the motor, and does not cause axial or radial space waste, thereby improving the space utilization rate of the motor.

[0028] (2) In the embodiment of the present invention, a centrifugal heat dissipation channel is integrated into the rotor, wherein the first centrifugal flow channel and the second centrifugal flow channel are respectively arranged on the outer sides of the front cover plate and the rear cover plate, and are formed by radial fin intervals, so as to generate centrifugal airflow when the rotor rotates; at the same time, two heat dissipation hole connection paths are designed, one of which is the first heat dissipation hole (front cover plate) → the second heat dissipation hole (first axial magnetic pole) → the first axial air gap; the other is the third heat dissipation hole (rear cover plate) → the fourth heat dissipation hole (second axial magnetic pole) → the second axial air gap; thus, the airflow is driven by the rotation of the rotor itself, so that the internal heat of the four-sided electromagnetic drive can be directly and effectively discharged through the heat dissipation paths at the axial ends of the rotor, without the need for an additional power source, so as to achieve efficient heat dissipation without increasing the complexity of the system, thereby effectively solving the technical problem of increased volume and mass caused by the traditional external cooling system. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly introduced below.

[0030] Figure 1 is a schematic structural diagram of a four-sided rotor electromagnetic drive with a self-fanning centrifugal structure according to an embodiment of the present invention;

[0031] Figure 2 is a schematic structural diagram of another viewing direction of a four-sided rotor electromagnetic drive with a self-fanning centrifugal structure according to an embodiment of the present invention after hiding the stator support;

[0032] Figure 3 is a break diagram of a four-sided rotor electromagnetic drive with a self-fanning centrifugal structure according to an embodiment of the present invention;

[0033] Figure 4 is an exploded view of a four-sided rotor electromagnetic drive with a self-fanning centrifugal structure according to an embodiment of the present invention;

[0034] Figure 5 is a schematic structural diagram of a stator core;

[0035] Figure 6 is a schematic layout diagram of the magnetization directions of the permanent magnets in the first radial magnetic pole array, the second radial magnetic pole array, the first axial magnetic pole array, or the second axial magnetic pole array;

[0036] Markings in the figure:

[0037] Stator 1; Stator support 11; Stator core 12; Coil winding 13; Central shaft 14; First radial tooth 15; Second radial tooth 16; First axial tooth 17; Second axial tooth 18; Heat conduction column 19;

[0038] Rotor 2; Rotor housing 20; Rotating shell 21; Rotating shaft sleeve 22; Front cover plate 23; Rear cover plate 24; First radial magnetic pole array 25; Second radial magnetic pole array 26; First axial magnetic pole array 27; Second axial magnetic pole array 28; Bearing 29; First centrifugal flow channel 210; Second centrifugal flow channel 211; First fin 212; Second fin 213; First heat dissipation hole 214; Second heat dissipation hole 215; Third heat dissipation hole 216; Fourth heat dissipation hole 217; Fifth heat dissipation hole 218; First axial flow channel 219; Second axial flow channel 220; Third axial flow channel 221; Fourth axial flow channel 222. Detailed implementation manners

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. in the present invention is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0041] As Figures 1 to 6 shown, a preferred embodiment of the present invention.

[0042] A four-sided rotor electromagnetic drive with a self-fanning centrifugal structure includes a stator 1 and a rotor 2.

[0043] The stator 1 includes a stator bracket 11, a stator core 12, and a coil winding 13; the stator bracket 11 and the stator core 12 are axially spaced apart and fixedly connected to the stator core 12; the stator bracket 11 is fixedly connected with a central shaft 14, the stator core 12 is in a circular ring shape, the central shaft 14 is axially inserted into the middle of the stator core 12 and is coaxial with the stator core 12; a plurality of first radial teeth 15 evenly distributed along the circumferential direction are provided on the outer periphery of the stator core 12, a plurality of second radial teeth 16 evenly distributed along the circumferential direction are provided on the inner periphery of the stator core 12, a plurality of first axial teeth 17 evenly distributed along the circumferential direction are provided at the front end of the stator core 12, and a plurality of second axial teeth 18 evenly distributed along the circumferential direction are provided at the rear end of the stator core 12; the coil winding 13 is rectangularly wound around the first radial teeth 15, the second radial teeth 16, the first axial teeth 17, and the second axial teeth 18.

[0044] The rotor 2 includes a rotor housing 20, a first radial pole array 25, a second radial pole array 26, a first axial pole array 27, and a second axial pole array 28; the rotor housing 20 is provided with a rotating housing 21, a rotating shaft sleeve 22, a front cover plate 23, and a rear cover plate 24. The front end of the rotating housing 21 is fixedly connected to the front cover plate 23. The rotating shaft sleeve 22 is rotatably connected to the central shaft 14 through a bearing 29. The front end of the rotating shaft sleeve 22 is fixedly connected to the front cover plate 23, and the rear end of the rotating shaft sleeve 22 is fixedly connected to the rear cover plate 24. The rear cover plate 24 is disposed between the stator support 11 and the stator core 12. The first radial pole array 25 is arranged in a circular ring shape on the inner circumference of the rotating housing 21. The second radial pole array 26 is arranged in a circular ring shape on the outer circumference of the rotating shaft sleeve 22. The first axial pole array 27 is arranged in a circular ring shape on the inner side of the front cover plate 23. The second axial pole array 28 is arranged in a circular ring shape on the inner side of the rear cover plate 24. The first radial pole array 25 and the first radial tooth 15 are spaced apart to form a first radial air gap. The second radial pole array 26 and the second radial tooth 16 are spaced apart to form a second radial air gap. The first axial pole array 27 and the first axial tooth 17 are spaced apart to form a first axial air gap. The second axial pole array 28 and the second axial tooth 18 are spaced apart to form a second axial air gap.

[0045] Thus, in the embodiment of the present invention, the first radial rotor (i.e., the first radial pole array 25), the second radial rotor (i.e., the second radial pole array 26), the first axial rotor (i.e., the first axial pole array 27), and the second axial rotor (i.e., the second axial pole array 28) respectively form an air-gap magnetic field in the radial and axial directions of the stator 1. When three-phase sinusoidal current excitations with a phase difference of 120 electrical degrees are applied to the coil windings 13 wound around the first radial tooth 15, the second radial tooth 16, the first axial tooth 17, and the second axial tooth 18, the air-gap magnetic field formed by the rotor 2 interacts with the symmetric current in the coil windings 13 to generate a rotating magnetomotive force, driving the first radial rotor, the second radial rotor, the first axial rotor, and the second axial rotor to rotate synchronously to output power and torque. This design of the four rotors 2 enables the effective utilization of the coil windings 13 at the ends of the motor. Without increasing the system volume, it can effectively increase the air-gap area of the motor for electromechanical energy conversion (generating torque), thereby increasing the torque density of the motor, and without causing waste of axial or radial space, improving the space utilization rate of the motor.

[0046] Moreover, the coil winding 13 is wound around the first radial tooth 15, the second radial tooth 16, the first axial tooth 17, and the second axial tooth 18 in a rectangular shape, so that the four sides of the coil winding 13 can interact with the radial magnetic flux and axial magnetic flux generated by the magnetic pole array to generate an output torque. That is to say, the coil winding 13 only forms an end winding at the position where the wire crosses the tooth slot adjacent to it (i.e., the winding part that does not interact with the permanent magnet magnetic field to generate torque), which can greatly reduce the length of the end winding of the stator 1 coil, reduce the weight of the stator 1 and the copper loss of the winding; and the end winding of the stator 1 coil will not increase with the increase of the axial length of the motor, ensuring the utilization rate of the coil winding 13.

[0047] In addition, the key technology of the embodiment of the present invention lies in adding a self-fan-cooled centrifugal structure. Specifically: as Figure 2 and Figure 3 shown, the rotor housing 20 is provided with a heat dissipation flow channel, and the heat dissipation flow channel includes a first centrifugal flow channel 210 provided on the side of the front cover plate 23 away from the first axial magnetic pole array 27 and a second centrifugal flow channel 211 provided on the side of the rear cover plate 24 away from the second axial magnetic pole array 28; the first centrifugal flow channel 210 is formed by a plurality of first fins 212 extending radially and evenly distributed in the circumferential direction of the front cover plate 23; the second centrifugal flow channel 211 is formed by a plurality of second fins 213 extending radially and evenly distributed in the circumferential direction of the rear cover plate 24; a plurality of first heat dissipation holes 214 corresponding to the positions of the permanent magnets in the first axial magnetic pole array 27 are provided in the first centrifugal flow channel 210; a second heat dissipation hole 215 communicating the first heat dissipation hole 214 and the first axial air gap is provided on the permanent magnet in the first axial magnetic pole array 27; a plurality of third heat dissipation holes 216 corresponding to the positions of the permanent magnets in the second axial magnetic pole array 28 are provided in the second centrifugal flow channel 211; a fourth heat dissipation hole 217 communicating the third heat dissipation hole 216 and the second axial air gap is provided on the permanent magnet in the second axial magnetic pole array 28.

[0048] Therefore, according to the electromagnetic drive of the four-sided rotor 2 with a self-fan cooling centrifugal structure of the embodiment of the present invention, the centrifugal heat dissipation channel is integrated into the rotor 2, wherein the first centrifugal channel 210 and the second centrifugal channel 211 are respectively arranged on the outside of the front cover plate 23 and the rear cover plate 24, and are formed by radial fin intervals, and generate centrifugal airflow when the rotor 2 rotates; at the same time, two heat dissipation hole communication paths are designed, one is the first heat dissipation hole 214 (front cover plate 23) → the second heat dissipation hole 215 (first axial magnetic pole) → the first axial air gap; the other is the third heat dissipation hole 216 (rear cover plate 24) → the fourth heat dissipation hole 217 (second axial magnetic pole) → the second axial air gap; thus, the airflow is driven by the rotation of the rotor 2 itself, which can directly and effectively cause the internal heat of the four-sided electromagnetic drive to be discharged through the heat dissipation paths at the axial ends of the rotor 2, without the need for an additional power source, to achieve efficient heat dissipation without increasing the complexity of the system, thereby effectively solving the technical problem of increased volume and mass caused by the traditional external cooling system.

[0049] For example, Figure 3 As shown, a fifth heat dissipation hole 218 connected to the inner cavity of the rotor housing 20 is provided on one side of the outer diameter of the front cover plate 23 to facilitate the introduction of external cold air into the inner cavity of the rotor 2, forming a forced convection cycle, directly cooling the permanent magnets, the air gap and the teeth of the stator 1, and improving the heat exchange efficiency.

[0050] For example, Figure 5 As shown, the first radial tooth 15, the second radial tooth 16, the first axial tooth 17 and the second axial tooth 18 are all provided with a tooth portion, a yoke portion connected to one end of the tooth portion and a pole shoe connected to the other end of the tooth portion; the tooth portion of the first radial tooth 15 is provided with a first axial flow channel 219 axially penetrating the entire tooth portion; the tooth portion of the second radial tooth 16 is provided with a second axial flow channel 220 axially penetrating the entire tooth portion; the first axial tooth 17 and the second axial tooth 18 are both provided with a third axial flow channel 221 axially penetrating the entire stator core 12. Thus, a heat conduction channel axially penetrating the stator core 12 is formed by the first axial flow channel 219, the second axial flow channel 220 and the third axial flow channel 221, connecting the two axial ends of the electromagnetic drive of the four-sided rotor 2 to form a forced convection path, and external cold air flows in from one end, flows through the teeth of the stator 1 to take away the heat, and is discharged from the other end, directly cooling the stator core 12, the coil winding 13 and other heat-generating components; and these axial flow channels are in direct contact with the heat source (such as the coil winding 13), shortening the heat conduction path, improving the heat dissipation efficiency, and effectively solving the technical problem that the internal heat of the stator 1 is difficult to be discharged by conduction due to the air gap thermal resistance; it can also be understood that these axial flow channels are integrated inside the teeth of the stator 1, without the need for an additional heat dissipation structure, which not only avoids dimensional expansion but also reduces the mass of the stator core 12.

[0051] For example, Figure 5As shown, a plurality of the third axial flow channels 221 are arranged at a radial interval along the first axial tooth 17 and the second axial tooth 18 to increase the heat dissipation area.

[0052] Exemplarily, the stator bracket 11 and the stator core 12 are fixedly connected by heat conducting columns 19. Thus, while the heat conducting columns 19 realize the fixed connection between the stator bracket 11 and the stator core 12, it is beneficial to conduct heat from the stator core 12 to the stator bracket 11, strengthening the heat conduction path from the stator 1 to the housing. In this embodiment, one end of the heat conducting column 19 is fixedly inserted into the first axial flow channel 219, and the other end of the heat conducting column 19 is fixedly inserted into the stator bracket 11; the number of the heat conducting columns 19 is half of the number of the first axial flow channels 219, and one heat conducting column 19 is inserted into every other first axial flow channel 219 to maximize the heat dissipation contact area on the premise of ensuring the structural strength. It can also be understood that since the heat conducting columns 19 are distributed in the peripheral area of the rear cover plate 24, the centrifugal air flow generated when the rotor 2 rotates can directly wash the surface of the heat conducting columns 19, accelerating the dissipation of heat on its surface and further improving the heat dissipation efficiency.

[0053] Exemplarily, as Figures 1 to 3 shown, the heat dissipation flow channel further includes a fourth axial flow channel 222 that axially penetrates through the inner diameter side of the front cover plate 23, the rotary shaft sleeve 22, and the inner diameter side of the rear cover plate 24 in sequence. The port plane of the fourth axial flow channel 222 on the side of the front cover plate 23 protrudes from the first centrifugal flow channel 210 so that it is not communicated with the first centrifugal flow channel 210, and the port of the fourth axial flow channel 222 on the side of the rear cover plate 24 is placed in the second centrifugal flow channel 211 so that it is communicated with the second centrifugal flow channel 211, thereby allowing external cold air to enter from the front cover plate 23 end of the rotor 2, flow axially through the area of the rotary shaft sleeve 22, and finally be discharged from the rear cover plate 24 end. Thus, the fourth axial flow channel 222 extends along the central axis 14 line direction of the rotor 2 to form a continuous through channel from the front part to the rear part of the rotor 2, and cooperates with the second centrifugal flow channel 211 of the rear cover plate 24 to construct a three-dimensional heat dissipation cycle of "axial suction - centrifugal diffusion", forcing the cold air to penetrate the core area of the rotor 2 and directly cooling mechanical components such as the rotary shaft sleeve 22 and the bearing 29, thereby solving the technical problem of heat accumulation in the central area (such as the shaft sleeve and the bearing installation position) inside the traditional rotor 2 due to the closed structure.

[0054] Exemplarily, as Figure 6As shown, the pole pitches of the first radial magnetic pole array 25, the second radial magnetic pole array 26, the first axial magnetic pole array 27, and the second axial magnetic pole array 28 are the same and each permanent magnet is aligned. The pole pitch: τ = 360° / 2P, where p is the number of pole pairs. The first radial magnetic pole array 25, the second radial magnetic pole array 26, the first axial magnetic pole array 27, and the second axial magnetic pole array 28 are all based on the center line of the permanent magnet corresponding to the same central angle and with the magnetization direction facing the air gap or away from the air gap. Every time the permanent magnet passes through a pole pitch, the magnetization direction alternates between facing away from the air gap and facing the air gap. Thus, the magnetic field lines generated by the first radial magnetic pole array 25 pass through the coil winding 13 wound around the first radial tooth 15 to form a first radial magnetic flux. The magnetic field lines generated by the second radial magnetic pole array 26 pass through the coil winding 13 wound around the second radial tooth 16 to form a second radial magnetic flux. The magnetic field lines generated by the first axial magnetic pole array 27 pass through the coil winding 13 wound around the first axial tooth 17 to form a first axial magnetic flux. The magnetic field lines generated by the second axial magnetic pole array 28 pass through the coil winding 13 wound around the second axial tooth 18 to form a second axial magnetic flux. Thus, the first radial magnetic flux, the second radial magnetic flux, the first axial magnetic flux, and the second axial magnetic flux constitute a three-dimensional magnetic flux. At the same time, since the first radial magnetic pole array 25 and the second radial magnetic pole array 26 magnetized alternately with N poles and S poles form a symmetric air gap magnetic field on the radial two sides of the stator 1, and the first axial magnetic pole array 27 and the second axial magnetic pole array 28 magnetized alternately with N poles and S poles form a symmetric air gap magnetic field at the axial two ends of the stator 1, this means that the radial magnetic flux and the axial magnetic flux will not pass through each other in the stator 1 yoke, enabling the decoupling of the radial magnetic flux and the axial magnetic flux, thereby realizing the decoupling of the three-dimensional magnetic flux, being able to reduce the thickness of the stator 1 yoke, and even being able to make it hollow, reducing the use of materials, thus reducing costs and weight. In addition, the hollow part of the stator core 12 also provides favorable conditions for setting up a heat dissipation flow channel in the internal space of the motor to further improve the torque output ability of the motor.

[0055] In this embodiment, the first radial magnetic pole array 25, the second radial magnetic pole array 26, the first axial magnetic pole array 27, and the second axial magnetic pole array 28 are all preferably Halbach magnetic pole arrays, which can achieve a strong magnetic field on one side while the magnetic field on the other side is extremely weak or almost zero, contributing to obtaining a more uniform magnetic field distribution in the radial or axial direction, and reducing the dissipation of the magnetic field, being able to reduce the usage amount of the magnet material while ensuring the magnetic field strength.

[0056] In the description of the present invention, it should be understood that unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" used in the present invention should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] The above-disclosed are only the preferred embodiments of the present invention, and of course, the scope of rights of the present invention cannot be limited thereby. Therefore, equivalent changes made according to the scope of the patent application of the present invention still fall within the scope covered by the present invention.

Claims

1. Four-sided rotor electromagnetic drive with self-cooling centrifugal structure, characterized by: including a rotor and a stator; The stator comprises a stator support, a stator core and a coil winding; the stator support is axially spaced from the stator core and fixedly connected to the stator core; the stator support is fixedly connected with a central axis, the stator core is annular, the central axis is axially inserted into the middle of the stator core and is coaxial with the stator core; the outer periphery of the stator core is provided with a plurality of first radial teeth uniformly distributed along its circumferential direction, the inner periphery of the stator core is provided with a plurality of second radial teeth uniformly distributed along its circumferential direction, the front end of the stator core is provided with a plurality of first axial teeth uniformly distributed along its circumferential direction, and the rear end of the stator core is provided with a plurality of second axial teeth uniformly distributed along its circumferential direction; the coil winding is rectangular and surrounds the first radial teeth, the second radial teeth, the first axial teeth and the second axial teeth; The rotor comprises a rotor housing, a first radial magnetic pole array, a second radial magnetic pole array, a first axial magnetic pole array and a second axial magnetic pole array; the rotor housing is provided with a rotating shell, a rotating sleeve, a front cover plate and a rear cover plate, the front end of the rotating shell is fixedly connected to the front cover plate, the rotating sleeve is rotatably connected to the central shaft through a bearing, the front end of the rotating sleeve is fixedly connected to the front cover plate, the rear end of the rotating sleeve is fixedly connected to the rear cover plate, and the rear cover plate is arranged between the stator bracket and the stator core; the first radial magnetic pole array is arranged in a circular ring shape on the rotating shell The first radial magnetic pole array is arranged in a circular ring shape on the outer periphery of the rotating sleeve, the first axial magnetic pole array is arranged in a circular ring shape on the inner side of the front cover plate, and the second axial magnetic pole array is arranged in a circular ring shape on the inner side of the rear cover plate; the first radial magnetic pole array and the first radial tooth interval are opposite to form a first radial air gap, the second radial magnetic pole array and the second radial tooth interval are opposite to form a second radial air gap, the first axial magnetic pole array and the first axial tooth interval are opposite to form a first axial air gap, and the second axial magnetic pole array and the second axial tooth interval are opposite to form a second axial air gap; The rotor housing is provided with a heat dissipation channel, and the heat dissipation channel includes a first centrifugal channel arranged on the side of the front cover plate away from the first axial magnetic pole array and a second centrifugal channel arranged on the side of the rear cover plate away from the second axial magnetic pole array; the first centrifugal channel is formed by a plurality of radially extending first fins evenly spaced along the circumferential direction of the front cover plate; the second centrifugal channel is formed by a plurality of radially extending second fins evenly spaced along the circumferential direction of the rear cover plate; a plurality of first heat dissipation holes corresponding to the positions of the permanent magnets in the first axial magnetic pole array are arranged in the first centrifugal channel; second heat dissipation holes connecting the first heat dissipation holes and the first axial air gap are arranged on the permanent magnets in the first axial magnetic pole array; a plurality of third heat dissipation holes corresponding to the positions of the permanent magnets in the second axial magnetic pole array are arranged in the second centrifugal channel; and fourth heat dissipation holes connecting the third heat dissipation holes and the second axial air gap are arranged on the permanent magnets in the second axial magnetic pole array.

2. The four-rotor electromagnetic drive with self-cooling centrifugal structure according to claim 1, characterized in that: A fifth heat dissipation hole communicating with the inner cavity of the rotor housing is provided on one side of the outer diameter of the front cover plate.

3. The four-rotor electromagnetic drive with self-cooling centrifugal structure according to claim 1, characterized in that: The tooth portion of the first radial tooth is provided with a first axial flow channel axially penetrating the entire tooth portion.

4. The four-rotor electromagnetic drive with self-cooling centrifugal structure as claimed in claim 3, characterized in that: The stator bracket and the stator core are fixedly connected via a heat-conducting column.

5. The four-rotor electromagnetic drive with self-cooling centrifugal structure as claimed in claim 4, characterized in that: One end of the heat-conducting column is fixedly inserted in the first axial flow channel, and the other end of the heat-conducting column is fixedly inserted on the stator bracket; the number of the heat-conducting columns is half the number of the first axial flow channels, and one heat-conducting column is inserted in every other first axial flow channel.

6. The four-rotor electromagnetic drive with self-cooling centrifugal structure according to claim 1, characterized in that: The tooth portion of the second radial tooth is provided with a second axial flow channel axially penetrating the entire tooth portion.

7. The four-rotor electromagnetic drive with self-cooling centrifugal structure according to claim 1, characterized in that: The first axial teeth and the second axial teeth are both provided with a third axial flow channel axially penetrating the entire stator core.

8. The four-rotor electromagnetic drive with self-cooling centrifugal structure according to claim 7, characterized in that: A plurality of the third axial flow passages are arranged at intervals along the radial direction of the first axial teeth and the second axial teeth.

9. The four-rotor electromagnetic drive with self-cooling centrifugal structure according to claim 1, characterized in that: The heat dissipation channel also includes a fourth axial channel which sequentially penetrates the inner diameter side of the front cover plate, the rotating sleeve and the inner diameter side of the rear cover plate in the axial direction.

10. The four-rotor electromagnetic drive with self-cooling centrifugal structure according to any one of claims 1 to 9, characterized in that: The pole pitches of the first radial magnetic pole array, the second radial magnetic pole array, the first axial magnetic pole array and the second axial magnetic pole array are the same and the permanent magnets are aligned, and the pole pitch is: τ=360° / 2P, where p is the number of pole pairs; the first radial magnetic pole array, the second radial magnetic pole array, the first axial magnetic pole array and the second axial magnetic pole array are all based on the center line of the permanent magnet corresponding to the same central angle and with the magnetization direction facing the air gap or away from the air gap, and the magnetization direction of the permanent magnet passing through each pole pitch alternately changes away from the air gap or toward the air gap.

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