CN105356699B - A kind of automobile-used birotor flux switch motor - Google Patents

Abstract

The invention discloses a dual-rotor magnetic flux switching motor for vehicles. The stator is composed of three-phase armature windings, N _s stator core modules and N _s armature slots, N _s = 3N _c , and N _c is single-phase The number of coils in the winding, N _s stator core modules are evenly distributed along the circumferential direction, and there is an armature slot between every two stator core modules, and the three-phase armature winding is placed in the armature slot; each stator core A hybrid permanent magnet module is embedded radially in the middle of the module. Each hybrid permanent magnet module consists of a ferrite permanent magnet and two identical NdFeB permanent magnets. In the middle of the permanent magnets, the ferrite permanent magnets are closely and seamlessly connected with the NdFeB permanent magnets on both sides; the adjacent permanent magnets form an obvious series magnetic circuit on the flux path, compared with the traditional magnetic circuit under the parallel magnetic circuit. By switching the permanent magnet motor, the problem of easy saturation of the stator teeth is significantly improved, and the utilization rate of the permanent magnets is effectively improved.

Description

A dual-rotor magnetic flux switching motor for vehicles

technical field

The invention belongs to the technical field of motor manufacturing, in particular to a double-rotor magnetic flux switching motor used for electric vehicles and the like.

Background technique

The flux switching motor adopts the stator permanent magnet structure. The armature winding and permanent magnet are located on the stator. There is neither armature winding nor permanent magnet on the rotor. The structure is simple, the operation is reliable, and the efficiency and power density are high. On the one hand, this type of flux switching motor following the principle of flux switching can greatly reduce or offset the high-order harmonic components in the permanent magnet flux linkage and induced electromotive force of a single winding coil due to the complementarity of the windings, making the motor in the use of Under the condition of centralized armature winding and rotor straight slot, high sinusoidal no-load permanent magnet flux linkage and induced electromotive force of each phase can be obtained; on the other hand, this type of motor, because the permanent magnet is embedded in the stator teeth, The dinner party effect is formed by the permanent magnets of adjacent teeth, which makes it easy for this type of motor to achieve a higher air gap magnetic field, thereby achieving a higher motor torque density and power density. However, with the deepening of the research and application of this type of flux switching motor, the inherent shortcomings of this type of motor are becoming increasingly apparent: 1. The permanent magnet is embedded in the middle of the stator teeth, and the effective cross-sectional area of the stator teeth is greatly reduced, making the motor When the main magnetic circuit passes through the stator teeth, it is easy to be saturated, the motor has a large magnetic flux leakage, and the magnetic field utilization rate is low. In addition, the unique stator magnetic flux leakage of this type of motor further reduces the utilization rate of the permanent magnet material of the motor; 2. In order to obtain higher air-gap magnetic density when the main magnetic circuit of the motor is saturated, the amount of permanent magnet materials used is also significantly higher than that of permanent magnet brushless motors of the same power level. With the continuous increase in the price of rare earth permanent magnet materials in recent years The obvious rise of its manufacturing cost will undoubtedly limit the further promotion and use of this type of motor.

It can be seen from the literature at home and abroad that the methods to reduce the amount of rare earth permanent magnet materials in permanent magnet motors mainly include: improving the utilization rate of permanent magnets, using DC auxiliary excitation, and using low-cost non-rare earth materials such as ferrite. In the document "Anovel hybrid excitation flux-switching motor for hybrid vehicles" (published in 2009, IEEE Transactions on Magnetics, Volume 45, Issue 10, Pages 4728-4731), by adding DC excitation windings to the stator, it not only reduces the rare earth permanent magnet The amount of material used also realizes the free adjustment of the air gap magnetic flux and expands the speed regulation range of the motor. However, due to the use of DC excitation windings, the structure of the motor becomes more complex, and at the same time increases the copper consumption and copper consumption of the motor, reducing the operating efficiency of the motor. On this basis, in the document "The performance of ahybrid excitation flux switching motor with ferrite magnets for EVs" (published at the IEEE Conference of Transportation Electrification Asia-Pacific in 2014), ferrite permanent magnets were used instead of rare earth permanent magnet excitation, effectively reducing the the manufacturing cost of the motor. However, due to the low magnetic energy product of ferrite, it is necessary to increase the torque density of the motor through the DC excitation winding, and the operating efficiency of the motor needs to be improved. Chinese Patent No. 201410508547.2 proposes a flux switching motor using hybrid permanent magnets. The motor uses both rare earth permanent magnets and ferrite permanent magnets for excitation, and a rare earth permanent magnet with high energy product is installed on the yoke of the stator. Magnets, ferrite permanent magnets with low magnetic energy product are installed on the teeth close to the stator, thus forming a hybrid permanent magnet module in which rare earth permanent magnets and ferrite permanent magnets are connected, which reduces the torque on the basis of ensuring a certain torque density. The manufacturing cost of the motor does not increase additional copper consumption, which ensures the efficiency of the motor. However, these motors have not solved the problem of magnetic flux leakage from the outer circle of the stator of the flux switching motor, resulting in a low utilization rate of the permanent magnets.

Therefore, how to reduce the amount of rare earth permanent magnet materials in the motor while maintaining relatively high torque density and efficiency of the motor is an urgent problem to be solved in the field of non-rare earth or low rare earth flux switching motors.

Contents of the invention

The purpose of the present invention is to solve the problems existing in the prior art, and propose a dual-rotor rare-earth magnet for vehicles with simple structure, good rotor robustness, high torque density, high efficiency, and high permanent magnet utilization rate. By switching the motor to meet the requirements of reducing the amount of rare earth permanent magnet materials while ensuring relatively high power density and efficiency.

In order to achieve the above object, the technical solution adopted by the present invention is: the double rotor in the present invention comprises an outer rotor iron core and an inner rotor iron core, the inner rotor iron core is coaxially sleeved in the outer rotor iron core, and the outer rotor iron core and the inner rotor iron core The stator is coaxially installed between the rotor cores, and the inner rotor core is coaxially fixed and sleeved outside the non-magnetic rotating shaft. There is an internal air gap between the inner rotor core outer ring surface and the stator inner ring surface, and the stator outer ring surface There is an external air gap on the surface of the inner ring of the outer rotor core, and the stator is composed of three-phase armature windings, N _s stator core modules and N _s armature slots, N _s = 3N _c , and N _c is single-phase The number of coils in the winding, N _s stator core modules are evenly distributed along the circumferential direction, and there is an armature slot between every two stator core modules, and the three-phase armature winding is placed in the armature slot; each stator core A hybrid permanent magnet module is embedded radially in the middle of the module. Each hybrid permanent magnet module consists of a ferrite permanent magnet and two identical NdFeB permanent magnets. In the middle of the permanent magnet, the ferrite permanent magnet is tightly and seamlessly connected with the NdFeB permanent magnets on both sides; the ferrite permanent magnet and the NdFeB permanent magnet in the same hybrid permanent magnet module have the same magnetization direction and are The circumference is tangentially magnetized, and the magnetization directions of two adjacent hybrid permanent magnet modules are opposite.

The outer rotor core and the inner rotor core have the same number of salient poles N _r , N _r = N _s ± K ₁ , K ₁ = 1, 2, 3..., N _c is the number of coils of single-phase winding; The radial centerlines between two adjacent salient poles of the outer rotor core coincide with the centerlines of the salient poles of the inner rotor core therebetween.

The outer rotor iron core and the inner rotor iron core are fixedly connected to an annular disc on the same axial end surface, and four circular ventilation holes are evenly distributed along the circumferential direction on the disc surface of the annular disc.

All the stator core modules and hybrid permanent magnet modules have the same center O as the non-magnetic rotating shaft and the stator, the distance from the center O to the inner ring of the stator is the radius R _si , and the distance to the outer ring of the stator is the radius R _so , and _0.5Rso < _Rsi < _0.6Rso .

The stator core module, the ferrite permanent magnet and the NdFeB permanent magnet are all fan-shaped; the radian of the NdFeB permanent magnet is β _NdFe , the radian of the ferrite permanent magnet is β _ferrite , and the radian of the _ferrite permanent magnet is NdFe The radian of the iron boron permanent magnet is three times that of β _NdFe ; the minimum arc occupied between the side of each stator core module and the side of the NdFeB permanent magnet is β _s , β _s >β _ferrite +2β _NdFe .

After the above-mentioned technical scheme is implemented, it has the following beneficial effects:

1. The outer rotor iron core and the inner rotor iron core of the present invention are coaxially fixed and connected by the ring disc at the end and then rotate together, so that the motor can form two inner and outer air layers while satisfying the characteristics of the single stator fixed part and the rotor moving part. gap structure. The permanent magnetic energy generated by the hybrid permanent magnet module on the stator can establish two independent permanent magnetic fields through two layers of air gaps, which can effectively convert the permanent magnetic energy of the supersaturated part of the stator teeth of the traditional flux switching permanent magnet motor To establish the external magnetic field of the motor. The electromagnetic torques acting on the iron cores of the inner and outer rotors of the dual rotors can be superimposed on each other, thereby effectively improving the torque output capability and power density of the motor. This special design not only avoids the problem of magnetic flux leakage in the outer circle of the stator of the traditional flux switching motor, improves the utilization rate of the permanent magnet, but also reduces the saturation degree of the stator teeth of the traditional flux switching permanent magnet motor, reducing the speed of the motor at high speed. The iron loss at the time limits the temperature rise of the motor.

2. The double-rotor structure of the present invention is connected to each other through an annular disc, and several circular holes are distributed on the annular disc, so that the air circulates inside the motor as the motor rotates, forming a cooling fan structure, which effectively improves the performance of the motor. cooling performance.

3. The stator of the present invention adopts a stator-yokeless structure design, combined with double rotors, so that adjacent permanent magnets form an obvious series magnetic circuit on the magnetic flux path. Compared with the traditional flux switching permanent magnet motor under the parallel magnetic circuit, this motor significantly improves the difficult technical problem that the stator teeth of this type of motor are easy to be saturated, and effectively improves the utilization rate of the permanent magnet.

4. The stator teeth of the modular stator core of the present invention adopt a novel "non-equal radian" design, which changes the direction of the change rate of the relative position angle of the stator and rotor by the magnetic co-energy contained in the air gap, so that the inner and outer layers of the motor The cogging moments generated by the gaps are superimposed and cancel each other out, so as to reduce the total cogging torque acting on the new dual rotors, and then obtain the effect of reducing the torque ripple, which is another innovation of the present invention.

5. The present invention uses high-performance NdFeB permanent magnet materials and cheap non-rare-earth ferrite permanent magnet materials at the same time, and the two permanent magnet materials of ferrite and NdFeB are connected in series, and the "magnetomotive force and According to the principle of magnetic flux balance, the two types of permanent magnet materials maintain a strict constraint relationship in size (the thickness of the ferrite permanent magnet is three times the thickness of the NdFeB permanent magnet), which maximizes the relationship between the two permanent magnet materials. Performance, to ensure relatively high torque density and power density of the motor while reducing the amount of NdFeB, thereby significantly reducing the manufacturing cost of the motor.

6. The present invention adopts the structure that the mixed magnetic material module is sandwiched between the stator core module, and in the mixed magnetic material module, the ferrite is located between the inner and outer NdFeB materials, thus avoiding the ferrite from being located at the stator end The magnetic saturation phenomenon at the end of the stator at the same time also improves the anti-demagnetization ability of the ferrite.

7. The hybrid magnetic material module used in the present invention is alternately magnetized tangentially in the circumferential direction, so that the magnetic field of the motor has a magnetic concentration characteristic, thereby increasing the magnetic flux density of the air gap.

8. The present invention only uses one set of armature windings, thus skillfully avoiding the electromagnetic coupling problem caused by the use of two sets of armature windings in the traditional double-layer air-gap permanent magnet motor, thus ensuring the stability and stability of the normal operation of the motor. reliability.

Description of drawings

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a three-dimensional structural disassembly schematic diagram of a dual-rotor flux switching motor for a vehicle of the present invention;

Fig. 2 is an axial appearance view of the present invention;

Fig. 3 is a radial cross-sectional schematic view of the annular disk in Fig. 2;

Fig. 4 is the enlarged schematic view of the radial section of the present invention after the annular disk is removed;

Fig. 5 is a schematic diagram of the stator structure, the magnetization direction of the permanent magnet and the installation and connection mode of the armature winding in Fig. 4;

Fig. 6 is the structure of single hybrid permanent magnet module in Fig. 4 and enlarged schematic diagram of geometric dimensioning;

Fig. 7 is a partial view along the circumferential direction and a schematic diagram of the magnetic flux when the present invention operates in the first position;

Fig. 8 is a schematic diagram of the magnetic flux of the present invention running from the first position in Fig. 7 to the second position;

Fig. 9 is a no-load magnetic field distribution diagram of the present invention;

Fig. 10 is a traditional 12/10 type flux switching motor magnetic field distribution diagram;

Fig. 11 is a magnetic field distribution diagram of a traditional 6/5 type flux switching motor;

Fig. 12 is a no-load counter electromotive force waveform diagram of the present invention;

In the figure: 1. Double rotor; 2. Outer rotor core; 3. Inner rotor core; 4. Ring disc; 5. Non-magnetic shaft; 6. Stator; 7. Stator core module; 8. Ferrite Permanent magnet; 9. NdFeB permanent magnet; 10. Hybrid permanent magnet module; 11. Non-magnetic stator connection parts; 12. Armature winding; 13. Armature slot; 14. Circular ventilation hole; 15. Outer rotor Iron core salient pole; 16. Iron core salient pole inside the rotor.

Detailed ways

Referring to FIG. 1 and FIG. 2 , the present invention consists of a double rotor 1 , a stator 6 , an armature winding 12 and a nonmagnetic rotating shaft 5 . Among them, the double rotor 1 is composed of an outer rotor core 2, an inner rotor core 3 and an annular disk 4. The inner rotor core 3 is coaxially spaced in the outer rotor core 2, and the outer rotor core 2 and the inner rotor core 3 is fixedly installed on the same end face of the axial direction with an annular disk 4, and the outer rotor core 2 and the inner rotor iron core 3 are fixedly connected together through the annular disk 4, and the connection method is riveting or welding, so that the double rotor 1 becomes A whole. The stator 6 is coaxially installed between the outer rotor iron core 2 and the inner rotor iron core 3, and the inner rotor iron core 3 is coaxially and fixedly sleeved outside the non-magnetic rotating shaft 5. The non-magnetic rotating shaft 5, the inner rotor iron core 3, the stator 6 and the outer rotor iron core 2 are coaxially set. The non-magnetic shaft 5 passes through the double rotor 1 and the annular disk 4 in the axial direction, and the non-magnetic shaft 5 drives the entire double rotor 1 to rotate coaxially through the inner rotor core 3 . Due to the special design of the double rotor 1, it forms a hollow cup-shaped rotating part in space.

In the radial direction, there is an inner air gap of 0.6 mm between the outer ring surface of the inner rotor core 3 and the inner ring surface of the stator 6, and there is a 0.6 mm air gap between the outer ring surface of the stator 6 and the inner ring surface of the outer rotor core 2. mm outer air gap.

The outer rotor core 2, the inner rotor core 3 and the stator 6 are all formed by laminating D23 silicon steel sheets with a thickness of 0.35 mm, and the lamination coefficient is 0.95. Both the non-magnetic rotating shaft 5 and the annular disk 4 are made of non-magnetic materials with high heat dissipation coefficient.

Referring to Fig. 3, in order to effectively improve the heat dissipation performance of the motor of the present invention, four circular ventilation holes 14 are evenly distributed along the circumferential direction on the disk surface of the annular disk 4, and the radius of each circular ventilation hole 14 is R ₁ , the distances between the centers of the four circular holes 14 and the center of the annular disk 4 are equal, all being L ₁ . During the rotation of the motor, the air circulates inside the motor through the circular ventilation holes 14 on the annular disk 4, which is beneficial to the heat dissipation of the motor.

Referring to Fig. 1, Fig. 4 and Fig. 5, the outer rotor core 2 and the inner rotor core 3 have the same number N _r of salient poles. The radial center line between two adjacent outer rotor core salient poles 15 coincides with the center line of the inner rotor iron core salient pole 16 between the two outer rotor core salient poles 15, on the same diameter , so that the relative positions of the salient poles 15 of the outer rotor core and the salient poles 16 of the inner rotor core in the circumferential direction are just staggered.

The stator 6 is composed of three-phase armature windings 12, N _s stator core modules 7 and N _s armature slots 13, N _s stator core modules 7 are evenly distributed along the circumferential direction, and the stator core modules 7 form a stator In the tooth part, there is an armature slot 13 between every two stator core modules 7 , and the three-phase armature winding 12 is placed in the armature slot 13 . Among them, N _s =3N _c , N _r =N _s ±K ₁ (K ₁ =1,2,3...), N _c is the number of coils contained in the single-phase winding, N _s can be 6, 12 or 18 , K ₁ correspondingly takes integers such as 1, 2, and 3.

The middle of each stator core module 7 is fixedly embedded with a hybrid permanent magnet module 10 radially, the stator core module 7 and the hybrid permanent magnet module 10 are fan-shaped structures, and the outer diameter of the hybrid permanent magnet module 10 is equal to the stator core module 7, the inner diameter of the hybrid permanent magnet module 10 is equal to the inner diameter of the stator core module 7. The hybrid permanent magnet module 10 and the stator core module 7 are glued together as a whole.

Referring to FIG. 4 and FIG. 5 , every two stator core modules 7 are fixedly connected through a non-magnetically permeable stator connecting part 11 . When fixing, a non-magnetic stator connecting part 11 is fixed between the outer edges of every two stator core modules 7, and another non-magnetic stator connecting part 11 is used between the inner edges of every two stator core modules 7. Fixed, the two stator connecting parts 11 are made of non-magnetic materials with high heat dissipation coefficient.

Each hybrid permanent magnet module 10 is made up of a ferrite permanent magnet 8 and two identical NdFeB permanent magnets 9, the ferrite permanent magnet 8 is in the middle of the two NdFeB permanent magnets 9, the ferrite permanent magnet 8 and The NdFeB permanent magnets 9 are fan-shaped structures, and the ferrite permanent magnets 8 are tightly and seamlessly connected with the NdFeB permanent magnets 9 on both sides to form a complete hybrid permanent magnet module 10 . The magnetization directions of a ferrite permanent magnet 8 and two NdFeB permanent magnets 9 in the same hybrid permanent magnet module 10 are the same and are all magnetized tangentially along the circumference, and the charging of two adjacent hybrid permanent magnet modules 10 The magnetic direction is opposite. In Fig. 5, "+" is the incoming wire direction of the armature winding 12, "-" is the outgoing wire direction of the armature winding 12, and A, B, and C are the three-phase windings of the motor. Among them, each phase winding is divided into N _c groups of coils (correspondingly, the number N _s of the stator core module 7 is 6, 12, 18, and N _c is 2, 4, 6), and the coils of each phase are centralized turns and placed in the armature slot 13.

Referring to FIG. 6 , all the stator core modules 7 and the hybrid permanent magnet modules 10 have the same center O, which coincides with the axes of the non-magnetically conductive rotating shaft 5 and the stator 6 . The distance from the center O to the inner ring of the stator 6 is the radius R _si , the distance from the center O to the outer ring of the stator 6 is the radius R _so , and 0.5R _so <R _si <0.6R _so . The radians of the two NdFeB permanent magnets 9 are equal, both being β _NdFe ; the radians of the ferrite permanent magnet 8 are β _ferrite . The radian β _ferrite of the ferrite permanent magnet 8 is three times of the radian β _NdFe of the NdFeB permanent magnet 9 . The minimum arc occupied between the side of each stator core module 7 and the side of the NdFeB permanent magnet 9 is β _s , and in order to ensure a certain mechanical strength, β _s >β _ferrite +2β _NdFe . The radian of the stator core module 7 is β _m , β _m =2β _s +2β _NdFe +β _ferrite .

Referring to FIG. 7 and FIG. 8 , when the motor of the present invention is working, during the operation of the motor, the magnetic flux (flux linkage) flowing through the stator core module 7 of the motor will switch directions according to different positions of the dual rotors 1 . As shown in Figure 7, the motor is running at the first position, and when the dual rotor 1 moves to the position shown in Figure 7, the relative position of the dual rotor 1 and the stator 6 is: since the relative motion direction of the dual rotor 1 is clockwise, Therefore, the order from left to right is: the continuous first and second outer rotor core salient poles 15 of the double rotor 1 are respectively opposite to the first and third stator core modules 7; The consecutive first and second inner rotor core salient poles 16 are opposite to the second and fourth stator core modules 7 respectively. At this time, the flux linkages generated by the ferrite permanent magnet 8 and the two NdFeB permanent magnets 9 are connected in series and pass through the armature winding 12 in a positive direction (clockwise). The path of the magnetic flux produced by the ferrite permanent magnet 8 and the two NdFeB permanent magnets 9 is clockwise as follows: passing through the second NdFeB permanent magnet 9, the first ferrite permanent magnet 8, the first NdFeB permanent magnet 9, first stator core module 7, outer air gap, first outer rotor core salient pole 15, outer rotor yoke, second outer rotor core salient pole 15, outer air gap , the third stator core module 7, the third NdFeB permanent magnet 9, the second ferrite permanent magnet 8, the fourth NdFeB permanent magnet 9, the fourth stator core module 7, the inner air Gap, second inner rotor core salient pole 16, inner rotor yoke, first inner rotor core salient pole 16, inner air gap, second stator core module 7. Therefore, in the position shown in FIG. 7 , the present invention has a stronger magnetic concentration effect and can provide a higher air-gap magnetic flux density.

When the dual rotor 1 moves to the second position as shown in Figure 8, the relative positions of the dual rotor 1 and the stator 6 are: in order from left to right, the continuous first and second positions of the dual rotor 1 The three outer rotor core salient poles 15 are respectively opposite to the second and fourth stator core modules 7; the first and second consecutive inner rotor core salient poles 16 of the double rotor 1 are respectively opposite to the first and The third stator core module 7 is opposite. At this time, the flux linkages generated by the ferrite permanent magnet 8 and the two NdFeB permanent magnets 9 are connected in series and pass through the armature winding 12 in the opposite direction (counterclockwise). The path of the magnetic flux generated by the ferrite permanent magnet 8 and the two NdFeB permanent magnets 9 is clockwise as follows: passing through the third NdFeB permanent magnet 9, the second ferrite permanent magnet 8, and the fourth NdFeB permanent magnet 9, fourth stator core module 7, outer air gap, second outer rotor core salient pole 15, outer rotor yoke, first outer rotor core salient pole 15, outer air gap , the second stator core module 7, the second NdFeB permanent magnet 9, the first ferrite permanent magnet 8, the first NdFeB permanent magnet 9, the first stator core module 7, the inner air Gap, first inner rotor core salient pole 16, inner rotor yoke, second inner rotor core salient pole 16, inner air gap, third stator core module 7. Therefore, in the position shown in FIG. 8 , the present invention has a stronger magnetic concentration effect and can provide a higher air-gap magnetic flux density. In addition, since in the first position shown in FIG. 7 , the magnetic flux generated by the ferrite permanent magnet 8 and the two NdFeB permanent magnets 9 passes through the armature winding 12 in a clockwise direction, while in the first position shown in FIG. 8 In the second position, the magnetic flux passes through the armature winding 12 in the counterclockwise direction, so when the relative positions of the stator 6 and the double rotor 1 are continuously switched, an alternating induction with bipolarity will be induced in the armature winding 12 electromotive force.

Referring to Fig. 9, Fig. 10 and Fig. 11, compared with the magnetic field distribution of the traditional flux switching motor in Fig. 10 and Fig. 11 by adopting the structural design of the present invention, the magnetic field distribution of the present invention avoids serious flux leakage in the outer ring of the stator 6 ingeniously and effectively To solve the problem, the present invention can effectively convert the permanent magnet magnetic energy of the supersaturated part of the stator teeth of the traditional magnetic flux switching permanent magnet motor into an external magnetic field for establishing the motor. Therefore, the present invention can not only reduce the saturation degree of the stator teeth of the conventional magnetic flux switching permanent magnet motor, but also superimpose the electromagnetic torques acting on the iron cores of the inner and outer rotors of the new double rotor, thereby effectively improving the torque of the motor output capability and power density.

Referring to Figure 12, it is the no-load back EMF waveform diagram of the present invention. It can be seen that the no-load back EMF waveform of the present invention shows a higher sine degree, and most of its harmonic content has been offset and compensated, and is suitable for brushless AC control operation. Therefore, the special winding arrangement of the present invention has the characteristics of the complementarity of the windings.

Claims (6)

1. A dual-rotor magnetic flux switching motor for vehicles, the dual-rotor (1) includes an outer rotor iron core (2) and an inner rotor iron core (3), and the inner rotor iron core of the outer rotor iron core (2) is coaxial and empty. core (3), the stator (6) is coaxially installed between the outer rotor core (2) and the inner rotor core (3), and the inner rotor core (3) is coaxially fixed on the non-magnetic rotating shaft (5) Outside, there is an internal air gap between the surface of the outer ring of the inner rotor core (3) and the surface of the inner ring of the stator (6), and there is an external air gap between the surface of the outer ring of the stator (6) and the surface of the inner ring of the outer rotor core (2) gap, which is characterized in that: the stator (6) is composed of three-phase armature windings, N _s stator core modules (7) and N _s armature slots (13), N _s =3N _c , N _c is a single The number of coils of the phase windings, N _s stator core modules (7) are evenly distributed along the circumferential direction, the armature slot (13) is between every two stator core modules (7), and the three-phase armature windings are placed in In the armature slot (13); a hybrid permanent magnet module (10) is fixed radially in the middle of each stator core module (7), and each hybrid permanent magnet module (10) is composed of a ferrite permanent magnet (8) consists of two identical NdFeB permanent magnets (9), the ferrite permanent magnet (8) is in the middle of the two NdFeB permanent magnets (9), and the ferrite permanent magnet (8) and the neodymium on both sides The iron-boron permanent magnets (9) are tightly and seamlessly connected; the magnetization directions of the ferrite permanent magnets (8) and the neodymium-iron-boron permanent magnets (9) in the same hybrid permanent magnet module (10) are the same and are tangential along the circumference For magnetization, the magnetization directions of two adjacent hybrid permanent magnet modules (10) are opposite. 2. According to claim 1, a magnetic flux switching motor with dual rotors for vehicles is characterized in that: the outer rotor core (2) and the inner rotor core (3) have the same number of salient poles N _r , N _r =N _s ±K ₁ , K ₁ =1,2,3..., N _c is the number of coils of the single-phase winding; the radial center line between two adjacent salient poles (15) of the outer rotor core and The center lines of the salient poles (16) of the inner rotor core coincide with each other. 3. A kind of magnetic flux switching motor with double rotors for vehicles according to claim 1, characterized in that: the axially identical end faces of the outer rotor iron core (2) and the inner rotor iron core (3) are fixedly connected with an annular disk ( 4), four circular ventilation holes are evenly distributed along the circumferential direction on the surface of the annular disc (4). 4. A kind of magnetic flux switching motor with dual rotors for vehicles according to claim 1, characterized in that: all stator core modules (7) and hybrid permanent magnet modules (10) have non-conductive rotating shafts (5) , the same center O of the stator (6), the distance from the center O to the inner ring of the stator (6) is the radius R _si , the distance to the outer ring of the stator (6) is the radius R _so , and 0.5R _so <R _si <0.6R _so . 5. A kind of double-rotor magnetic flux switching motor for vehicles according to claim 1, characterized in that: the stator core module (7), the ferrite permanent magnet (8) and the NdFeB permanent magnet (9) are all fan-shaped ; The radian of the NdFeB permanent magnet (9) is β _NdFe , the radian of the ferrite permanent magnet (8) is β _ferrite , and the radian β _ferrite of the ferrite permanent magnet (8) is the radian of the NdFeB permanent magnet (9) Three times that of β _NdFe . 6. According to claim 5, a dual-rotor magnetic flux switching motor for vehicles is characterized in that: the space between the side of each stator core module (7) and the side of the NdFeB permanent magnet (9) The minimum radian is β _s , β _s >β _ferrite +2β _NdFe .