Permanent magnet and soft magnet mixed heterogeneous magnetic pole array and electromagnetic drive

Abstract

The invention discloses a permanent magnet and soft magnet mixed heterogeneous magnetic pole array which is formed by splicing a plurality of magnetic pole configuration units with closed magnetic circuits in a circular ring shape. Each magnetic pole configuration unit comprises two first permanent magnets with right triangle-shaped cross sections, two second permanent magnets with trapezoidal cross sections and a composite soft magnet with an isosceles triangle-shaped cross section; the vertex angle of the first permanent magnet points to the air gap; the vertex angle of the composite soft magnet deviates from the air gap; the second permanent magnet is provided with a first inclined side surface spliced with the waist side surface of the first permanent magnet and a second inclined side surface spliced with the waist side surface of the composite soft magnet; in the same magnetic pole configuration unit, the magnetizing directions of the first permanent magnet and the second permanent magnet on the two symmetrical sides enable magnetic field lines to be gradually gathered towards the side, close to an air gap, of the composite soft magnet. The invention also discloses an electromagnetic drive using the heterogeneous magnetic pole array. By adopting the magnetic pole array, the magnetic field intensity and the magnetic shielding characteristic can be simultaneously improved, the eddy current loss of the magnetic pole array can be reduced, and the permanent magnet consumption is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and particularly relates to a heterogeneous pole array with permanent magnet and soft magnet hybrid and electromagnetic drive. Background Art

[0002] A motor is a device that works based on the principle of electromagnetic drive. Changing the permanent magnet pole array of the motor rotor (such as: the combination of the size, thickness, shape, and magnetization direction of the permanent magnet) is an effective means to effectively improve the air-gap magnetic density of the motor, thereby improving the torque. Among them, the Halbach pole array is the main pole array currently used to improve the air-gap magnetic density. Compared with the radial alternating pole array, the magnetic flux per pole of the Halbach pole array is provided by multiple permanent magnets, and the mode of radial and tangential hybrid magnetization makes the Halbach have a certain magnetic shielding characteristic, which can reduce the magnetic field at the rotor back iron to a certain extent, so that the thickness of the back iron can be thinned, the rotor mass can be reduced, and the motor can obtain better dynamic characteristics.

[0003] However, for the traditional Halbach pole array, its magnetic shielding characteristic is incomplete, and the permanent magnet loss is large when applied to high-frequency motors. And because the magnetic flux per pole of the Halbach pole array is provided by three poles, the air-gap magnetic density is larger than that of the radial alternating pole array. However, there are permanent magnets with radial magnetization, so the magnetic circuit must pass through the back iron, so the thickness of the back iron cannot be too thin, otherwise it will cause serious magnetic saturation, thereby reducing the air-gap magnetic density. In addition, after the Halbach air-gap magnetic field is enhanced, a large amount of eddy current will be generated in the Halbach pole array by the magnetic field harmonics, resulting in serious heating of the permanent magnet and the risk of thermal demagnetization, especially for high-speed motors. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, one of the purposes of the present invention is to provide a heterogeneous pole array with permanent magnet and soft magnet hybrid that can not only improve the magnetic field strength and magnetic shielding characteristic at the same time, but also reduce the eddy current loss of the pole array and reduce the amount of permanent magnet used (which also reduces the cost); the second purpose of the present invention is to provide an electromagnetic drive applying the heterogeneous pole array.

[0005] One of the purposes of the present invention is achieved by adopting the following technical solutions:

[0006] A heterogeneous pole array of permanent magnet and soft magnet hybrid, which is formed by circularly splicing a plurality of pole configuration units with closed magnetic circuits. The pole configuration unit includes two first permanent magnets with right triangle cross-sections, two second permanent magnets with trapezoid cross-sections and a composite soft magnet with isosceles triangle cross-section. The vertex angles of the first permanent magnets point to the air gap. The vertex angle of the composite soft magnet deviates from the air gap. The second permanent magnet is provided with a first inclined side surface that fits with the waist side surface of the first permanent magnet and a second inclined side surface that fits with the waist side surface of the composite soft magnet. The magnetic circuit trend directions of two adjacent pole configuration units are opposite. Among two adjacent pole configuration units, taking the composite soft magnet in one of the pole configuration units as the center, the magnetization directions of the first permanent magnets on both symmetric sides of the composite soft magnet are tangential magnetization and point to the second permanent magnet, and the magnetization directions of the second permanent magnets on both symmetric sides are inclined magnetization towards the air gap side and point to the composite soft magnet. While in the other pole configuration unit, taking the composite soft magnet in it as the center, the magnetization directions of the first permanent magnets on both symmetric sides of the composite soft magnet are tangential magnetization and point to the adjacent pole configuration unit, and the magnetization directions of the second permanent magnets on both symmetric sides are inclined magnetization away from the air gap side and point to the first permanent magnet.

[0007] Implementing the heterogeneous pole array of permanent magnet and soft magnet hybrid of the embodiments of the present invention, compared with the prior art, has the following beneficial effects:

[0008] In the heterogeneous pole array with permanent magnet and soft magnet hybrid of the embodiment of the present invention, through the combined structure of the first permanent magnet with a right triangle cross-section, the second permanent magnet with a trapezoid cross-section, and the composite soft magnet with an isosceles triangle cross-section, and by designing the magnetization directions of the first permanent magnet and the second permanent magnet, the magnetic field lines gradually converge towards the side of the composite soft magnet close to the air gap. Therefore, it has a very strong magnetic concentration characteristic. Moreover, the mating surfaces between the first permanent magnet and the second permanent magnet, and between the second permanent magnet and the composite soft magnet are both designed as inclined surfaces, and the apex angle of the composite soft magnet faces away from the air gap, so that the surface of the composite soft magnet on the side close to the air gap has a relatively large surface area to generate a relatively large air gap magnetic flux, further strengthening its magnetic concentration characteristic (i.e., large air gap magnetic density). Secondly, through the mutual cooperation of the permanent magnet and the composite soft magnet, the permanent magnet magnetized towards or away from the air gap is completely removed, effectively enhancing the magnetic shielding characteristic of the pole array (i.e., small magnetic density at the back iron). Furthermore, the magnetic density on the back iron side of this heterogeneous pole array is almost zero, reducing the mass of the back iron, and even the rotor back iron can be completely removed, creating favorable conditions for improving the motor torque. Finally, by adding a composite soft magnet (SMC) with an isosceles triangle shape and high resistivity, the eddy current of the permanent magnet is truncated, effectively reducing the eddy current loss of the rotor permanent magnet. And this composite soft magnet has a higher magnetic permeability than the permanent magnet material, reducing the system magnetic resistance while increasing the reluctance torque, so the output torque will not be reduced. That is to say, through this heterogeneous pole array with permanent magnet and soft magnet hybrid, while not affecting the output torque, the eddy current loss of the pole array is effectively reduced, creating favorable conditions for the heat dissipation of high torque density electromagnetic drive.

[0009] In summary, compared with the traditional Halbach pole array, the heterogeneous pole array with permanent magnet and soft magnet hybrid proposed in the embodiment of the present invention can not only improve the magnetic field intensity and magnetic shielding characteristic at the same time, but also reduce the eddy current loss of the pole array, reduce the usage amount of permanent magnets, and lower the cost.

[0010] The second object of the present invention is achieved by adopting the following technical solution:

[0011] The electromagnetic drive includes a stator and a rotor. The rotor can rotate relative to the stator around an axis, and the rotor is provided with the heterogeneous pole array with permanent magnet and soft magnet hybrid described above.

[0012] As a preferred solution of the above electromagnetic drive, the stator includes a stator bracket, a stator core and a coil winding; the stator bracket is axially opposite to the stator core and fixedly connected to the stator core by bolts; the stator bracket is fixedly connected with a central shaft, the stator core is annular, the central shaft is inserted axially into the middle of the stator core and is coaxial with the stator core; a plurality of first radial teeth evenly distributed along the circumferential direction are provided on the outer circumference of the stator core, a plurality of second radial teeth evenly distributed along the circumferential direction are provided on the inner circumference of the stator core, a plurality of first axial teeth evenly distributed along the circumferential direction are provided at the front end of the stator core, and a plurality of second axial teeth evenly distributed along the circumferential direction are provided at the rear end of the stator core; the coil winding is rectangularly wound around the first radial teeth, the second radial teeth, the first axial teeth and the second axial teeth;

[0013] The rotor includes a rotor housing and 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 respectively fixed on the rotor housing; the rotor housing is rotatably connected to the central shaft through a bearing; 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 arranged in an annular shape, the first radial magnetic pole array is spaced opposite to the first radial teeth to form a first radial air gap, the second radial magnetic pole array is spaced opposite to the second radial teeth to form a second radial air gap, the first axial magnetic pole array is spaced opposite to the first axial teeth to form a first axial air gap, and the second axial magnetic pole array is spaced opposite to the second axial teeth to form a second axial air gap; 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 the heterogeneous magnetic pole arrays of permanent magnet and soft magnetic hybrid, 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 their first permanent magnets, second permanent magnets and composite soft magnets are aligned one by one, pole pitch: τ = 360° / 2P, p is the number of pole pairs.

[0014] As a preferred solution of the above electromagnetic drive, the first radial teeth, the second radial teeth, the first axial teeth and the second axial teeth are all provided with tooth parts, yoke parts connected to one end of the tooth parts and pole shoes connected to the other end of the tooth parts; the yoke parts of the first radial teeth, the yoke parts of the second radial teeth, the yoke parts of the first axial teeth and the yoke parts of the second axial teeth enclose a hollow chamber with a rectangular axial cross-section.

[0015] As a preferred solution of the above electromagnetic drive, the yoke of the first radial tooth and the yoke of the second radial tooth are connected by a web plate and form an integral radial tooth; the first axial tooth is fixed to the front end of the integral radial tooth by welding or screws or adhesive, and the second axial tooth is fixed to the rear end of the integral radial tooth by welding or screws or adhesive.

[0016] As a preferred solution of the above electromagnetic drive, a plurality of web plates are evenly distributed in the circumferential direction, and the plurality of web plates divide the hollow chamber into a plurality of chamber units; aluminum blocks are embedded in the chamber units.

[0017] As a preferred solution of the above electromagnetic drive, first groove edges that cooperate with the outer periphery of the yoke of the first axial tooth or the second axial tooth are respectively provided at both axial ends of the yoke of the first radial tooth, and the groove depth of the first groove edge is the same as the outer periphery thickness of the yoke of the first axial tooth or the second axial tooth; second groove edges that cooperate with the inner periphery of the yoke of the first axial tooth or the second axial tooth are respectively provided at both axial ends of the yoke of the second radial tooth, and the groove depth of the second groove edge is the same as the inner periphery thickness of the yoke of the first axial tooth or the second axial tooth.

[0018] As a preferred solution of the above electromagnetic drive, the tooth profile of the tooth part of the first radial tooth in the radial cross-section is rectangular, and the tooth groove formed between two adjacent first radial teeth is a trapezoidal groove; the tooth profile of the tooth part of the second radial tooth in the radial cross-section is rectangular, and the tooth groove formed between two adjacent second radial teeth is a trapezoidal groove; the tooth profile of the tooth part of the first axial tooth in the radial cross-section is trapezoidal, and the tooth groove formed between two adjacent first axial teeth is a parallel groove; the tooth profile of the tooth part of the second axial tooth in the radial cross-section is trapezoidal, and the tooth groove formed between two adjacent second axial teeth is a parallel groove.

[0019] As a preferred solution of the above electromagnetic drive, the rotor housing is provided with a rotating housing, a rotating shaft sleeve, a front cover plate and a rear cover plate. The front end of the rotating housing 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, and the rear end of the rotating shaft sleeve is fixedly connected to the rear cover plate. The rear cover plate is arranged between the stator bracket and the stator core; the first radial magnetic pole array is fixedly arranged on the inner circumference of the rotating housing, the second radial magnetic pole array is fixedly arranged on the outer circumference of the rotating shaft sleeve, the first axial magnetic pole array is fixedly arranged on the inner side of the front cover plate, and the second axial magnetic pole array is fixedly arranged on the inner side of the rear cover plate.

[0020] As a preferred solution of the above electromagnetic drive, an output shaft coaxial with the central shaft is installed on the outer side of the front cover plate.

[0021] Implementing the electromagnetic drive of the embodiments of the present invention has the following beneficial effects compared with the prior art:

[0022] The electromagnetic drive of the embodiments of the present invention adopts a heterogeneous pole array composed of a permanent magnet and a composite soft magnet, which can better exert the advantage of very small magnetic leakage on one side compared with the traditional Halbach pole array. It has a better magnetic shielding effect compared with the prior art, reduces the back iron mass, and can even avoid the use of the back iron, reducing the energy consumption during the operation of the electromagnetic drive. Moreover, without increasing the volume of the permanent magnet, it significantly enhances the magnetic focusing characteristics on the air gap side, improves the electromagnetic output torque performance, and increases the thrust density. In addition, it can effectively reduce the eddy current loss of the pole array, creating favorable conditions for the heat dissipation of the high torque density electromagnetic drive. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below.

[0024] Figure 1 It is a schematic structural diagram of the heterogeneous pole array of the permanent magnet and soft magnet hybrid of the embodiments of the present invention; only two adjacent pole configuration units in the heterogeneous pole array are shown in the figure;

[0025] Figure 2 It is a finite element simulation comparison diagram of the magnetic field distributions of the heterogeneous pole array of the permanent magnet and soft magnet hybrid of the embodiments of the present invention and the traditional Halbach pole array;

[0026] Figure 3 It is a comparison diagram of the air gap magnetic density curves of the heterogeneous pole array of the permanent magnet and soft magnet hybrid of the embodiments of the present invention and the traditional Halbach pole array;

[0027] Figure 4 It is a comparison diagram of the magnetic density curves at the back iron of the heterogeneous pole array of the permanent magnet and soft magnet hybrid of the embodiments of the present invention and the traditional Halbach pole array;

[0028] Figure 5 It is a simulation comparison diagram of the eddy current losses of the heterogeneous pole array of the permanent magnet and soft magnet hybrid of the embodiments of the present invention and the traditional Halbach pole array;

[0029] Figure 6 It is a comparison diagram of the eddy current loss curves of the heterogeneous pole array of the permanent magnet and soft magnet hybrid of the embodiments of the present invention and the traditional Halbach pole array;

[0030] Figure 7 It is an axonometric view of the electromagnetic drive of the embodiments of the present invention;

[0031] Figure 8 It is a front view of the electromagnetic drive of the embodiments of the present invention;

[0032] Figure 9 is a sectional view taken along the A-A direction in the structure shown; Figure 8 shown in the structure of the A-A direction sectional view;

[0033] Figure 10 is a connection structure diagram of the stator core and the coil winding;

[0034] Figure 11 is an exploded view of the stator core and the coil winding;

[0035] Figure 12 is a schematic diagram of the magnetization direction arrangement of each permanent magnet in the first radial pole array, the second radial pole array, the first axial pole array or the second axial pole array;

[0036] Figure 13 is the output torque waveform diagram of the axial-radial composite flux electromagnetic drive, the double-rotor radial flux electromagnetic drive and the double-rotor axial flux electromagnetic drive.

[0037] Markings in the figure:

[0038] Stator 1; stator bracket 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; hollow chamber 19; aluminum block 110; web 111; first slot edge 112; second slot edge 113; tooth part a; yoke part b; pole shoe c;

[0039] Rotor 2; rotor housing 21; rotating shell 211; rotating shaft sleeve 212; front cover plate 213; rear cover plate 214; first radial pole array 22a; second radial pole array 22b; first axial pole array 22c; second axial pole array 22d; bearing 23; pole configuration unit 220; first permanent magnet 221; second permanent magnet 222; composite soft magnetic 223; first inclined side 224; second inclined side 225;

[0040] Output shaft 3. Detailed implementation manners

[0041] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with 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 of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0042] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "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. It 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 therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0043] As Figures 1 to 6 shown, a preferred embodiment of the present invention.

[0044] A heterogeneous pole array of permanent magnet and soft magnet hybrid is formed by circularly splicing a plurality of pole configuration units 220 with closed magnetic circuits. The pole configuration unit 220 includes two first permanent magnets 221 with right-angled triangle cross-sections, two second permanent magnets 222 with trapezoidal cross-sections, and a composite soft magnet 223 (i.e., SMC) with an isosceles triangle cross-section; the apex angle of the first permanent magnet 221 points to the air gap; the apex angle of the composite soft magnet 223 faces away from the air gap; the second permanent magnet 222 is provided with a first inclined side 224 that fits with the waist side surface of the first permanent magnet 221 and a second inclined side 225 that fits with the waist side surface of the composite soft magnet 223; the magnetic circuit trend directions of two adjacent pole configuration units 220 are opposite; in two adjacent pole configuration units 220, with the composite soft magnet 223 in one of the pole configuration units 220 as the center, the magnetization directions of the first permanent magnets 221 on both symmetric sides of the composite soft magnet 223 are tangential magnetization and point to the second permanent magnet 222, and the magnetization directions of the second permanent magnets 222 on both symmetric sides are inclined magnetization towards the air gap side and point to the composite soft magnet 223; while in the other pole configuration unit 220, with the composite soft magnet 223 in it as the center, the magnetization directions of the first permanent magnets 221 on both symmetric sides of the composite soft magnet 223 are tangential magnetization and point to the adjacent pole configuration unit 220, and the magnetization directions of the second permanent magnets 222 on both symmetric sides are inclined magnetization away from the air gap side and point to the first permanent magnet 221.

[0045] It should be noted that when the heterogeneous pole array is used as a radial pole array, due to the circular arrangement of the above-mentioned right-angled triangle, trapezoid, and isosceles triangle and the requirements of the air gap between the rotor and the stator, the surfaces of the permanent magnets with different shapes facing or facing away from the air gap form an arc shape, as shown in Figure 12In addition, in two adjacent magnetic pole configuration units 220, since the magnetization directions of the first permanent magnets 221 on the clockwise side of the previous magnetic pole configuration unit 220 and the first permanent magnets 221 on the counterclockwise side of the next magnetic pole configuration unit 220 are the same, the two mutually joined first permanent magnets 221 can be designed as an integral permanent magnet with an isosceles triangle cross-section.

[0046] For the heterogeneous magnetic pole array with permanent magnet and soft magnet hybrid according to the embodiment of the present invention, through the combined structure of the first permanent magnet 221 with a right triangle cross-section, the second permanent magnet 222 with a trapezoid cross-section, and the composite soft magnet 223 with an isosceles triangle cross-section, and by designing the magnetization directions of the first permanent magnet 221 and the second permanent magnet 222, the magnetic field lines are gradually gathered towards the side of the composite soft magnet 223 close to the air gap, so it has a strong magnetic focusing characteristic; moreover, the joining surfaces between the first permanent magnet 221 and the second permanent magnet 222 and between the second permanent magnet 222 and the composite soft magnet 223 are both designed as inclined surfaces, and the apex angle of the composite soft magnet 223 faces away from the air gap, so that the surface of the composite soft magnet 223 on the side close to the air gap has a large surface area to generate a large air gap magnetic flux, further strengthening its magnetic focusing characteristic (i.e., large air gap magnetic density, see Figure 2 and Figure 3 ); secondly, through the mutual cooperation of the permanent magnet and the composite soft magnet 223, the permanent magnets magnetized towards or away from the air gap are completely removed, effectively enhancing the magnetic shielding characteristic of the magnetic pole array (i.e., small magnetic density at the back iron, see Figure 2 and Figure 4 ); furthermore, the magnetic density on the back iron side of this heterogeneous magnetic pole array is almost zero, creating favorable conditions for completely removing the rotor back iron and improving the motor torque; finally, by adding the composite soft magnet 223 with a high resistivity isosceles triangle, the eddy current of the permanent magnet is truncated, effectively reducing the eddy current loss of the rotor permanent magnet. As shown in Figure 5 and Figure 6 , the eddy current loss of the Halbach magnetic pole array is about 104.58 W, and that of the heterogeneous magnetic pole array is about 65.9 W. That is to say, the eddy current loss of the heterogeneous magnetic pole array is reduced by 37.3%. It should be noted that this composite soft magnet 223 has a higher magnetic permeability than the permanent magnet material, increasing the reluctance torque while reducing the system magnetic resistance, so it will not reduce the output torque; that is to say, through this heterogeneous magnetic pole array with permanent magnet and soft magnet hybrid, while not affecting the output torque, the eddy current loss of the magnetic pole array is effectively reduced, creating favorable conditions for the heat dissipation of high torque density electromagnetic drive.

[0047] Therefore, compared with the traditional Halbach pole array, the heterogeneous pole array with permanent magnet and soft magnet hybrid proposed in the embodiments of the present invention can not only improve the magnetic field strength and magnetic shielding characteristics simultaneously, but also reduce the eddy current loss of the pole array, reduce the amount of permanent magnet used, and lower the cost.

[0048] As Figures 7 to 12 shown, based on the above-mentioned heterogeneous pole array with permanent magnet and soft magnet hybrid, the embodiments of the present invention also provide an electromagnetic drive, which includes a stator 1 and a rotor 2. The rotor 2 can rotate relative to the stator 1 around an axis. The above-mentioned heterogeneous pole array with permanent magnet and soft magnet hybrid is provided on the rotor 2. Thus, the electromagnetic drive of the embodiments of the present invention adopts a heterogeneous pole array composed of a permanent magnet and a composite soft magnet 223, which can better exert the advantage of very small leakage magnetic flux on one side compared with the traditional Halbach pole array, has a better magnetic shielding effect compared with the prior art, reduces the mass of the back iron, and even can avoid the use of the back iron, reducing the energy consumption during the operation of the electromagnetic drive; and, without increasing the volume of the permanent magnet, significantly enhances the magnetic focusing characteristics on the air gap side, improves the electromagnetic output torque performance, and increases the thrust density; in addition, it can also effectively reduce the eddy current loss of the pole array, creating favorable conditions for the heat dissipation of the high torque density electromagnetic drive.

[0049] Furthermore, taking the axial-radial composite flux electromagnetic drive as an example, the electromagnetic drive proposed in the embodiments of the present invention has a first radial rotor, a second radial rotor, a first axial rotor and a second axial rotor. The above-mentioned heterogeneous pole array with permanent magnet and soft magnet hybrid is respectively arranged on each rotor. The specific scheme is as follows:

[0050] The stator 1 includes a stator bracket 11, a stator core 12 and a coil winding 13; the stator bracket 11 is axially opposite to the stator core 12 and is fixedly connected to the stator core 12 by bolts; 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 inserted axially 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 arranged on the outer circumference of the stator core 12, a plurality of second radial teeth 16 evenly distributed along the circumferential direction are arranged on the inner circumference of the stator core 12, a plurality of first axial teeth 17 evenly distributed along the circumferential direction are arranged at the front end of the stator core 12, and a plurality of second axial teeth 18 evenly distributed along the circumferential direction are arranged 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.

[0051] The rotor 2 includes a rotor housing 21, and a first radial magnetic pole array 22a, a second radial magnetic pole array 22b, a first axial magnetic pole array 22c, and a second axial magnetic pole array 22d that are respectively fixed on the rotor housing 21; the rotor housing 21 is rotatably connected to the central shaft 14 through a bearing 23; the first radial magnetic pole array 22a, the second radial magnetic pole array 22b, the first axial magnetic pole array 22c, and the second axial magnetic pole array 22d are all arranged in a circular ring shape. The first radial magnetic pole array 22a is spaced opposite to the first radial tooth 15 to form a first radial air gap, the second radial magnetic pole array 22b is spaced opposite to the second radial tooth 16 to form a second radial air gap, the first axial magnetic pole array 22c is spaced opposite to the first axial tooth 17 to form a first axial air gap, and the second axial magnetic pole array 22d is spaced opposite to the second axial tooth 18 to form a second axial air gap; the first radial magnetic pole array 22a, the second radial magnetic pole array 22b, the first axial magnetic pole array 22c, and the second axial magnetic pole array 22d are all the heterogeneous magnetic pole arrays of the permanent magnet soft magnetic mixture. The pole pitches of the first radial magnetic pole array 22a, the second radial magnetic pole array 22b, the first axial magnetic pole array 22c, and the second axial magnetic pole array 22d are the same, and their respective first permanent magnets 221, second permanent magnets 222, and composite soft magnets 223 are aligned one by one. The pole pitch: τ = 360° / 2P, where p is the number of pole pairs.

[0052] It can be understood that the electromagnetic drive of the embodiment of the present invention forms an air gap magnetic field in the radial and axial directions of the stator 1 through the first radial rotor (i.e., the first radial magnetic pole array 22a), the second radial rotor (i.e., the second radial magnetic pole array 22b), the first axial rotor (i.e., the first axial magnetic pole array 22c), and the second axial rotor (i.e., the second axial magnetic pole array 22d). 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 output torque. This design of the four rotors effectively utilizes 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 will not cause waste of axial or radial space, improving the space utilization rate of the motor.

[0053] It should also be noted that the electromagnetic drive of the embodiment of the present invention has achieved significant technical progress in the following aspects:

[0054] (1) The magnetic field lines generated by the first radial pole array 22a 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 pole array 22b 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 pole array 22c 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 pole array 22d 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 pole array 22a and the second radial pole array 22b magnetized alternately with N and S poles form a symmetric air-gap magnetic field on the radial two sides of the stator 1, and the first axial pole array 22c and the second axial pole array 22d magnetized alternately with N 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 yoke of the stator 1, so that the radial magnetic flux and the axial magnetic flux are decoupled, thereby realizing the decoupling of the three-dimensional magnetic flux, being able to reduce the thickness of the stator 1 yoke, even making it hollow, reducing the use of materials, and thus reducing the cost and weight; in addition, the hollow part of the stator core 12 also provides favorable conditions for setting a heat dissipation flow channel in the internal space of the motor, so as to further improve the torque output capacity of the motor.

[0055] (2) 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 the axial magnetic flux generated by the corresponding pole arrays to generate an output torque. That is to say, the coil winding 13 will only form an end winding at the part 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 coil, reduce the stator weight and the copper loss of the winding; and the end winding of the stator coil will not increase with the increase of the axial length of the motor, ensuring the utilization rate of the coil winding 13.

[0056] As Figure 13 shown, Figure 13 The output torque waveforms of the axial-radial composite magnetic flux electromagnetic drive, the dual-rotor radial magnetic flux electromagnetic drive, and the dual-rotor axial magnetic flux electromagnetic drive with the same volume are compared. It can be seen from the figure that the axial-radial composite magnetic flux electromagnetic drive has the largest average output torque because the end winding is removed and an additional two layers of electromagnetic interaction air gaps are added, and it is 1.95 and 2.06 times that of the dual-rotor radial magnetic flux electromagnetic drive and the dual-rotor axial magnetic flux electromagnetic drive respectively.

[0057] Exemplarily, as Figure 11As 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, a yoke portion b connected to one end of the tooth portion a, and a pole shoe c connected to the other end of the tooth portion a; the yoke portions b of the first radial tooth 15, the yoke portions b of the second radial tooth 16, the yoke portions b of the first axial tooth 17, and the yoke portions b of the second axial tooth 18 enclose a hollow chamber 19 with a rectangular axial cross-section. Since the radial magnetic flux and the axial magnetic flux are decoupled, the thickness of each yoke portion b can be designed to be smaller, and the volume of the hollow chamber 19 can be made larger, greatly reducing the system weight; in addition, an aluminum block 110 with a low mass density and high thermal conductivity can be embedded in the hollow chamber 19, which can effectively reduce the thermal resistance of the heat conduction path from the inside to the outside and will not significantly increase the mass of the stator 1.

[0058] Exemplarily, the first axial tooth 17 and the second axial tooth 18 are both made of a solid composite soft magnetic material (SMC) or laminated silicon steel sheets, and the first radial tooth 15 and the second radial tooth 16 are both formed by laminating silicon steel sheets.

[0059] Exemplarily, as Figure 11 shown, for the convenience of assembly, the yoke portion b of the first radial tooth 15 and the yoke portion b of the second radial tooth 16 are connected by a web 111 and form an integral radial tooth; the first axial tooth 17 is fixed to the front end of the integral radial tooth by welding or screws or adhesives, and the second axial tooth 18 is fixed to the rear end of the integral radial tooth by welding or screws or adhesives. Further, a plurality of webs 111 are evenly distributed in the circumferential direction, and the plurality of webs divide the hollow chamber 19 into a plurality of chamber units; the aluminum block 110 is embedded in the chamber unit.

[0060] Exemplarily, as Figure 11 shown, first groove edges 112 that cooperate with the outer circumference of the yoke portion b of the first axial tooth 17 or the second axial tooth 18 are respectively provided at both axial ends of the yoke portion b of the first radial tooth 15, and the groove depth of the first groove edge 112 is the same as the outer circumference thickness of the yoke portion b of the first axial tooth 17 or the second axial tooth 18; second groove edges 113 that cooperate with the inner circumference of the yoke portion b of the first axial tooth 17 or the second axial tooth 18 are respectively provided at both axial ends of the yoke portion b of the second radial tooth 16, and the groove depth of the second groove edge 113 is the same as the inner circumference thickness of the yoke portion b of the first axial tooth 17 or the second axial tooth 18. Such a design can further reduce the axial length of the stator 1 and at the same time make the connection structure between the axial tooth and the radial tooth more compact and reliable.

[0061] Exemplarily, as Figure 10 and Figure 11As shown, in the electromagnetic drive of the embodiment of the present invention, the first radial teeth 15, the second radial teeth 16, the first axial teeth 17, and the second axial teeth 18 share a set of coil windings 13. Therefore, the cross-sectional area of the coil windings occupying the tooth slots is the same. When the tooth slots formed by the radial teeth are parallel slots, the tooth parts a of the radial teeth are trapezoidal in the axial projection. However, the radial magnetic flux does not change with the change of the radius of the stator 1. Therefore, the tooth shapes of the tooth parts a of the first radial teeth 15 in the radial cross-section and the tooth shapes of the tooth parts a of the second radial teeth 16 in the radial cross-section are both designed as rectangles, and the tooth slots formed between two adjacent first radial teeth 15 and the tooth slots formed between two adjacent second radial teeth 16 are both trapezoidal slots. This can avoid material waste caused by the large area of the radial tooth iron core. Since the axial magnetic flux increases with the increase of the radius, the tooth shapes of the tooth parts a of the first axial teeth 17 in the radial cross-section and the tooth shapes of the tooth parts a of the second axial teeth 18 in the radial cross-section are both designed as trapezoids, and the tooth slots formed between two adjacent first axial teeth 17 and the tooth slots formed between two adjacent second axial teeth 18 are parallel slots. This can avoid magnetic saturation.

[0062] Exemplarily, as Figure 9 shown, the rotor housing 21 is provided with a rotating housing 211, a rotating shaft sleeve 212, a front cover plate 213, and a rear cover plate 214. The front end of the rotating housing 211 is fixedly connected to the front cover plate 213. The rotating shaft sleeve 212 is rotatably connected to the central shaft 14 through a bearing. The front end of the rotating shaft sleeve 212 is fixedly connected to the front cover plate 213. The rear end of the rotating shaft sleeve 212 is fixedly connected to the rear cover plate 214. The rear cover plate 214 is disposed between the stator bracket 11 and the stator core 12. The first radial magnetic pole array 22a is fixedly arranged on the inner circumference of the rotating housing 211. The second radial magnetic pole array 22b is fixedly arranged on the outer circumference of the rotating shaft sleeve 212. The first axial magnetic pole array 22c is fixedly arranged on the inner side of the front cover plate 213. The second axial magnetic pole array 22d is fixedly arranged on the inner side of the rear cover plate 214. Such a design can integrate the first radial rotor, the second radial rotor, the first axial rotor, and the second axial rotor to ensure that the four rotor components can output torque synchronously, with a compact and reliable structure.

[0063] Exemplarily, as Figures 7 to 9 shown, an output shaft 3 coaxial with the central shaft 14 is installed on the outer side of the front cover plate 213 to facilitate power output to the outside.

[0064] 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.

[0065] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the 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. A permanent magnetic and soft magnetic hybrid heterogeneous magnetic pole array, characterized by: The invention is composed of a plurality of magnetic pole configuration units with closed magnetic circuits, which are spliced ​​in a circular ring shape, and the magnetic pole configuration units include two first permanent magnets with right-angled triangle cross sections, two second permanent magnets with trapezoidal cross sections, and a composite soft magnet with an isosceles triangle cross section; the vertex angle of the first permanent magnet points to the air gap; the vertex angle of the composite soft magnet is away from the air gap; the second permanent magnet is provided with a first oblique side surface spliced ​​with the waist side surface of the first permanent magnet and a second oblique side surface spliced ​​with the waist side surface of the composite soft magnet; The magnetic circuits of two adjacent magnetic pole configuration units have opposite directions; in two adjacent magnetic pole configuration units, with the composite soft magnetic in one of the magnetic pole configuration units as the center, the magnetization directions of the first permanent magnets on both symmetrical sides of the composite soft magnetic are tangential magnetization and point to the second permanent magnet, and the magnetization directions of the second permanent magnets on both symmetrical sides are magnetized obliquely toward the air gap and point to the composite soft magnetic; and in the other magnetic pole configuration unit, with the composite soft magnetic in it as the center, the magnetization directions of the first permanent magnets on both symmetrical sides of the composite soft magnetic are tangential magnetization and point to the adjacent magnetic pole configuration unit, and the magnetization directions of the second permanent magnets on both symmetrical sides are magnetized obliquely away from the air gap and point to the first permanent magnet.

2. Electromagnetic drive, characterized in that: It comprises a stator and a rotor, wherein the rotor can rotate around an axis relative to the stator, and the rotor is provided with the permanent magnetic and soft magnetic hybrid heterogeneous magnetic pole array as claimed in claim 1.

3. The electromagnetic drive according to claim 2, characterized in that: The stator comprises a stator support, a stator core and a coil winding; the stator support is axially opposite to the stator core and is fixedly connected to the stator core by bolts; 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 in its circumferential direction, the inner periphery of the stator core is provided with a plurality of second radial teeth uniformly distributed in its circumferential direction, the front end of the stator core is provided with a plurality of first axial teeth uniformly distributed in its circumferential direction, and the rear end of the stator core is provided with a plurality of second axial teeth uniformly distributed in 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 and 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 respectively fixed on the rotor housing; the rotor housing is rotatably connected to the central axis through a bearing; 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 arranged in a circular ring shape, the first radial magnetic pole array and the first radial tooth are spaced to form a first radial air gap, the second radial magnetic pole array and the second radial tooth are spaced to form a second radial air gap, the first axial magnetic pole array The first axial tooth array is spaced relative to the first axial tooth to form a first axial air gap, and the second axial magnetic pole array is spaced relative to the second axial tooth to form a second axial air gap; 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 permanent magnet and soft magnet mixed heterogeneous magnetic pole arrays, 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 have the same pole pitch and their respective first permanent magnets, second permanent magnets and composite soft magnets are aligned one by one, and the pole pitch is: τ=360° / 2P, where p is the number of pole pairs.

4. The electromagnetic drive according to claim 3, characterized in that: The first radial tooth, the second radial tooth, the first axial tooth and the second axial tooth 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 yoke portion of the first radial tooth, the yoke portion of the second radial tooth, the yoke portion of the first axial tooth and the yoke portion of the second axial tooth enclose a hollow chamber with a rectangular axial cross-section.

5. The electromagnetic drive according to claim 4, characterized in that: The yoke of the first radial tooth and the yoke of the second radial tooth are connected through a spoke plate to form an integrated radial tooth; the first axial tooth is fixed to the front end of the integrated radial tooth by welding, screws or adhesive, and the second axial tooth is fixed to the rear end of the integrated radial tooth by welding, screws or adhesive.

6. The electromagnetic drive according to claim 5, characterized in that: A plurality of spoke plates are evenly distributed along the circumferential direction, and the plurality of spoke plates divide the hollow chamber into a plurality of chamber units; and aluminum blocks are embedded in the chamber units.

7. The electromagnetic drive according to claim 4, characterized in that: The axial ends of the yoke of the first radial tooth are respectively provided with first groove edges that match the outer periphery of the yoke of the first axial tooth or the second axial tooth, and the groove depth of the first groove edge is consistent with the thickness of the outer periphery of the yoke of the first axial tooth or the second axial tooth; the axial ends of the yoke of the second radial tooth are respectively provided with second groove edges that match the inner periphery of the yoke of the first axial tooth or the second axial tooth, and the groove depth of the second groove edge is consistent with the thickness of the inner periphery of the yoke of the first axial tooth or the second axial tooth.

8. The electromagnetic drive according to claim 4, characterized in that: The tooth shape of the tooth portion of the first radial tooth in the radial cross section is rectangular, and the tooth groove formed between two adjacent first radial teeth is a trapezoidal groove; the tooth shape of the tooth portion of the second radial tooth in the radial cross section is rectangular, and the tooth groove formed between two adjacent second radial teeth is a trapezoidal groove; the tooth shape of the tooth portion of the first axial tooth in the radial cross section is trapezoidal, and the tooth groove formed between two adjacent first axial teeth is a parallel groove; the tooth shape of the tooth portion of the second axial tooth in the radial cross section is trapezoidal, and the tooth groove formed between two adjacent second axial teeth is a parallel groove.

9. The electromagnetic drive according to any one of claims 3 to 8, characterized in that: 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 fixedly arranged on the inner periphery of the rotating shell, the second radial magnetic pole array is fixedly arranged on the outer periphery of the rotating sleeve, the first axial magnetic pole array is fixedly arranged on the inner side of the front cover plate, and the second axial magnetic pole array is fixedly arranged on the inner side of the rear cover plate.

10. The electromagnetic drive according to claim 9, characterized in that: An output shaft coaxially arranged with the central axis is installed on the outer side of the front cover plate.

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