CN211556999U - Rotor structure and motor with same - Google Patents

Abstract

The utility model provides a rotor structure and have its motor. The rotor structure includes: the rotor body, a plurality of main permanent magnet grooves have been seted up on the rotor body, and two side departments of the radial direction extension of rotor body in edge in each main permanent magnet groove all are provided with supplementary permanent magnet groove, are provided with main permanent magnet in each main permanent magnet groove, are provided with supplementary permanent magnet in each supplementary permanent magnet inslot. The auxiliary permanent magnets are arranged on the two side edges of the main permanent magnet, the magnetic path trend of a demagnetization magnetic field is changed, the working point of the main permanent magnet is improved, the area of a demagnetization area of the main permanent magnet is reduced, the demagnetization resistance of the motor is improved, meanwhile, the auxiliary permanent magnets provide magnetic flux for air gaps, the flux linkage of the motor is improved, the running current of the motor is reduced, the copper consumption of the motor is reduced, and the efficiency of the motor is improved.

Description

Rotor structure and motor with same

Technical Field

The utility model relates to an electrical equipment technical field particularly, relates to a rotor structure and have its motor.

Background

The motor with the permanent magnet tangential magnetization structure can generate higher air gap flux density than a permanent magnet radial magnetization motor due to the magnetic gathering effect, so that the motor has higher torque-current ratio and torque-volume ratio, and is increasingly applied to occasions such as servo systems, electric traction, office automation, household appliances and the like.

Because the tangential permanent magnet motor in the prior art adopts a magnetic circuit structure with single permanent magnet connected in parallel, the working point of a rotor permanent magnet is lower than that of a radial permanent magnet motor, the efficiency of the motor is easily reduced, and the risk of demagnetization exists in a severe environment, so that the motor cannot run.

SUMMERY OF THE UTILITY MODEL

A primary object of the present invention is to provide a rotor structure and motor having the same to solve the problem of low motor efficiency in the prior art.

In order to achieve the above object, according to an aspect of the present invention, there is provided a rotor structure including: the rotor body, a plurality of main permanent magnet grooves have been seted up on the rotor body, and two side departments of each main permanent magnet groove that extend along the radial direction of rotor body all are provided with supplementary permanent magnet groove, are provided with main permanent magnet in each main permanent magnet groove, and each supplementary permanent magnet inslot is provided with supplementary permanent magnet, and wherein, the distance between the supplementary permanent magnet groove that is located same main permanent magnet groove both sides sets up outwards gradually along the radial direction of rotor body.

Further, the first end in main permanent magnet groove is close to the shaft hole setting of rotor body, and the shaft hole setting is kept away from along rotor body's radial direction to the second end in main permanent magnet groove, and the first end in supplementary permanent magnet groove is close to the shaft hole setting, and the shaft hole setting is kept away from to the second end in supplementary permanent magnet groove, and the plane that the terminal surface place in the second end in main permanent magnet groove intersects with supplementary permanent magnet groove.

Furthermore, a central angle corresponding to a connecting line between the end parts, close to the outer edge of the rotor body, of the auxiliary permanent magnets on the same magnetic pole is I, and a central angle formed between the geometric center lines of the two adjacent main permanent magnets is J, wherein I/J is more than or equal to 0.08.

Furthermore, I/J is less than or equal to 0.3.

Further, the side of the auxiliary permanent magnet opposite to the main permanent magnet has the same polarity.

Furthermore, the auxiliary permanent magnet is in a strip shape, and an included angle formed between the geometric center line of the auxiliary permanent magnet in the long side direction and the geometric center line of the main permanent magnet groove is A, wherein the included angle is more than or equal to 70 degrees and more than or equal to 20 degrees.

Furthermore, the maximum distance between the end part of the auxiliary permanent magnet close to the shaft hole and the outer edge of the main permanent magnet close to the rotor body is B, the length of the main permanent magnet along the radial direction of the rotor body is C, and 0.18 is more than or equal to B/C.

Further, the minimum distance between the end part of the auxiliary permanent magnet close to the outer edge side of the rotor body and the outer edge of the rotor body is F, wherein 1.5 ≧ F/≧ 1, and is the length of an air gap between the stator and the rotor body.

Furthermore, the thickness of the auxiliary permanent magnet is D, the thickness of the rotor body is O, wherein D/O is more than or equal to 0.4 and more than or equal to 0.05.

Further, the coercive force of the auxiliary permanent magnet is higher than that of the main permanent magnet.

Further, the end of the auxiliary permanent magnet groove on the side far away from the shaft hole is arranged with a distance from the outer edge of the rotor body to form a first magnetism isolating bridge, and the thickness of the first magnetism isolating bridge along the radial direction of the rotor body is uniformly arranged.

Further, the end part of the auxiliary permanent magnet groove close to one side of the shaft hole and the main permanent magnet groove are arranged with a distance to form a second magnetism isolating bridge, and the thickness of the second magnetism isolating bridge along the radial direction of the rotor body is uniformly arranged.

Furthermore, the auxiliary permanent magnet is of an arc-shaped structure and is arranged in a bending mode towards the magnetic pole center line of the rotor core, or the auxiliary permanent magnet is arranged in a bending mode away from the magnetic pole center line of the rotor core.

Furthermore, the central angle corresponding to the connecting line of the shortest distance between the end parts of the auxiliary permanent magnets on the same magnetic pole, which are close to the outer edge of the rotor body, is K, wherein K/J is more than or equal to 0.3 and more than or equal to 0.1.

Furthermore, the radian of the auxiliary permanent magnet is L1, wherein the radian is more than or equal to 85 degrees and less than or equal to 90 degrees in L1 degrees.

Furthermore, one end, close to the shaft hole, of the auxiliary permanent magnet groove is communicated with the main permanent magnet groove, and one end, close to the outer edge of the rotor body, of the auxiliary permanent magnet groove is arranged at a distance from the main permanent magnet groove.

Further, the maximum distance between the end part of the auxiliary permanent magnet close to the shaft hole and the outer edge of the main permanent magnet close to the rotor body is D1, the length of the main permanent magnet in the radial direction of the rotor body is C, and D1/C is less than or equal to 0.4.

Furthermore, the long sides of the auxiliary permanent magnets extend along the circumferential direction of the rotor body, the central angle formed by connecting lines of the two ends of the auxiliary permanent magnets and the shaft hole is C1, the angle of the magnetic pole of the rotor body is B1, wherein 0.3 is more than or equal to C1/B1 is more than or equal to 0.1.

Furthermore, one end of the auxiliary permanent magnet slot facing the main permanent magnet slot is arranged at a distance from the main permanent magnet slot to form a third magnetic isolation bridge, and the width of the third magnetic isolation bridge is F1, wherein 2 is more than or equal to F1/> 1.

Further, the thickness of the auxiliary permanent magnet in the radial direction of the rotor body is H1, wherein 0.4 ≧ H1/O ≧ 0.05.

Further, an air groove is formed between one end of the auxiliary permanent magnet, facing the center line of the magnetic pole, and the auxiliary permanent magnet groove, a fourth magnetism isolating bridge is formed between the air groove and the outer edge of the rotor body, the thickness of the fourth magnetism isolating bridge is G, and the ratio of G to 0.8 is more than or equal to 1.8.

Further, the auxiliary permanent magnet slot communicates with the main permanent magnet slot.

Further, the auxiliary permanent magnets located at both sides of the main permanent magnet are different in length.

Further, the auxiliary permanent magnets positioned at both sides of the center line of the same magnetic pole are symmetrically arranged with respect to the center line of the magnetic pole.

Furthermore, the lengths of the auxiliary permanent magnets positioned on the two sides of the central line of the same magnetic pole are different.

Further, the outer edge magnetic pole direction of the auxiliary permanent magnet facing the rotor body is the same as the magnetic pole direction of the rotor body.

Further, the magnetization direction of the main permanent magnet is along the circumferential direction of the rotor body, and the magnetization direction of the auxiliary permanent magnet is along the radial direction of the rotor body. According to another aspect of the present invention, there is provided a motor, including a rotor structure, the rotor structure is the above-mentioned rotor structure.

Use the technical scheme of the utility model, both sides limit department that is located main permanent magnet all is provided with supplementary permanent magnet, has changed the magnetic circuit trend in demagnetization magnetic field, improves main permanent magnet's operating point for the regional area of demagnetization of main permanent magnet reduces, thereby improves the anti demagnetization ability of motor, and supplementary permanent magnet provides the magnetic flux to the air gap simultaneously, has improved the flux linkage of motor, has reduced the operating current of motor, reduces motor copper loss, improves motor efficiency.

Drawings

The accompanying drawings, which form a part of the present application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 shows a schematic structural view of a first embodiment of a rotor structure according to the invention;

fig. 2 shows a schematic structural view of a second embodiment of a rotor structure according to the invention;

fig. 3 shows a schematic structural view of a third embodiment of a rotor structure according to the invention;

fig. 4 shows a schematic structural view of a fourth embodiment of a rotor structure according to the invention;

fig. 5 shows a schematic structural view of a fifth embodiment of a rotor structure according to the invention;

fig. 6 shows a schematic structural view of a sixth embodiment of a rotor structure according to the invention;

fig. 7 shows a schematic structural view of a seventh embodiment of a rotor structure according to the invention;

fig. 8 shows a schematic structural view of an eighth embodiment of a rotor structure according to the invention;

fig. 9 shows a schematic structural view of a ninth embodiment of a rotor structure according to the invention;

fig. 10 shows a schematic structural view of a tenth embodiment of a rotor structure according to the invention;

fig. 11 shows a schematic structural view of an eleventh embodiment of a rotor structure according to the invention;

fig. 12 shows a schematic structural view of a twelfth embodiment of a rotor structure according to the invention;

fig. 13 shows a schematic structural view of a thirteenth embodiment of a rotor structure according to the invention;

FIG. 14 illustrates a prior art rotor structure demagnetization diagram;

fig. 15 shows a schematic demagnetization structure of a fourteenth embodiment of a rotor structure according to the invention;

fig. 16 shows a schematic demagnetization structure of a fifteenth embodiment of a rotor structure according to the invention;

fig. 17 shows a schematic demagnetization structure of a sixteenth embodiment of a rotor structure according to the invention;

figure 18 shows a graph comparing the demagnetized area of an electric machine according to the present invention with that of a prior art electric machine;

fig. 19 shows a flux linkage size comparison of a motor according to the present invention and a prior art motor.

Wherein the figures include the following reference numerals:

10. a rotor body; 11. a shaft hole; 12. a first magnetic isolation bridge; 13. a second magnetic isolation bridge; 14. a third magnetic isolation bridge; 15. a fourth magnetic isolation bridge;

20. a primary permanent magnet;

30. an auxiliary permanent magnet;

40. an air tank.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Exemplary embodiments according to the present application will now be described in more detail with reference to the accompanying drawings. These exemplary embodiments may, however, be embodied in many different forms and should not be construed as limited to only the embodiments set forth herein. It is to be understood that these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art, in the drawings, it is possible to enlarge the thicknesses of layers and regions for clarity, and the same devices are denoted by the same reference numerals, and thus the description thereof will be omitted.

As shown in fig. 1 to 13 and fig. 15 to 19, according to an embodiment of the present application, there is provided a rotor structure including: rotor body 10, a plurality of main permanent magnet grooves have been seted up on rotor body 10, two sides departments of each main permanent magnet groove that extend along rotor body 10's radial direction all are provided with supplementary permanent magnet groove, each main permanent magnet inslot is provided with main permanent magnet 20, each supplementary permanent magnet inslot is provided with supplementary permanent magnet 30, wherein, as shown in fig. 1 to 3, be located the distance between the supplementary permanent magnet groove of same main permanent magnet groove both sides, along the outside setting that increases gradually of rotor body 10's radial direction. Alternatively, as shown in fig. 4 and 5, the distances between the auxiliary permanent magnet slots located on both sides of the same main permanent magnet slot are gradually increased outward in the radial direction of the rotor body 10. The magnetic circuit of the rotor structure can be further optimized by the arrangement, and the demagnetization resistance and efficiency of the motor with the rotor structure are improved.

In this embodiment, the auxiliary permanent magnets are arranged at the two side edges of the main permanent magnet, so that the magnetic path trend of the demagnetization magnetic field is changed, the working point of the main permanent magnet is improved, the demagnetization area of the main permanent magnet is reduced, the demagnetization resistance of the motor is improved, the auxiliary permanent magnets provide magnetic flux for the air gap, the flux linkage of the motor is improved, the running current of the motor is reduced, the copper consumption of the motor is reduced, and the efficiency of the motor is improved.

Wherein, the first end in main permanent magnet groove is close to the shaft hole 11 setting of rotor body 10, and the second end in main permanent magnet groove is kept away from shaft hole 11 setting along rotor body 10's radial direction, and the first end in supplementary permanent magnet groove is close to shaft hole 11 setting, and shaft hole 11 setting is kept away from to the second end in supplementary permanent magnet groove, and the plane at the terminal surface place of the second end in main permanent magnet groove intersects with supplementary permanent magnet groove. The arrangement can effectively improve the flux linkage of the motor, reduce the area of a demagnetization area, reduce the running current of the motor, reduce the copper consumption of the motor and improve the efficiency of the motor. Specifically, as shown in fig. 14, the demagnetization area region in the related art is W1, and the areas of demagnetization regions W2, W3, and W4 in fig. 15 to 17 are all smaller than W1.

Further, the central angle corresponding to the connecting line between the ends of the auxiliary permanent magnets 30 on the same magnetic pole close to the outer edge of the rotor body 10 is I, and the central angle formed between the geometric center lines of two adjacent main permanent magnets 20 is J, wherein I/J is greater than or equal to 0.08. Preferably, I/J is 0.3 or less. This arrangement enables the motor efficiency to be optimised.

As shown in fig. 1 to 8, the side of the auxiliary permanent magnet 30 opposite to the main permanent magnet 20 has the same polarity. Further optimize the magnetic circuit of rotor structure, improve the anti effect of demagnetization energy of the motor that has this rotor structure.

As shown in fig. 1, the auxiliary permanent magnet 30 is in a strip shape, and an included angle formed between a geometric center line of the auxiliary permanent magnet 30 in the long side direction and a geometric center line of the main permanent magnet slot is a, wherein 70 degrees ≧ a ≧ 20 degrees. The maximum distance between the end part of the auxiliary permanent magnet 30 close to the shaft hole 11 and the outer edge of the main permanent magnet 20 close to the rotor body 10 is B, the length of the main permanent magnet 20 along the radial direction of the rotor body 10 is C, wherein 0.18 is more than or equal to B/C. The arrangement can improve the demagnetization resistance and efficiency of the motor.

In order to further improve the efficiency of the motor, the minimum distance between the end part of the auxiliary permanent magnet 30 close to the outer edge of the rotor body 10 and the outer edge of the rotor body 10 is F, wherein 1.5 ≧ F/≧ 1 is the length of the air gap between the stator and the rotor body 10. The thickness of the auxiliary permanent magnet 30 is D, the thickness of the rotor body 10 is O, wherein D/O is more than or equal to 0.4 and more than or equal to 0.05.

Further, the coercive force of the auxiliary permanent magnet 30 is higher than that of the main permanent magnet 20. This arrangement can improve the reliability of the motor.

As shown in fig. 2, the end of the auxiliary permanent magnet slot on the side away from the shaft hole 11 is disposed with a distance from the outer edge of the rotor body 10 to form a first magnetic bridge 12. The thickness of the first magnetic bridges 12 in the radial direction of the rotor body 10 is uniformly provided. The end of the auxiliary permanent magnet slot on the side close to the shaft hole 11 is arranged with a distance from the main permanent magnet slot to form a second magnetic isolation bridge 13, and the thickness of the second magnetic isolation bridge 13 in the radial direction of the rotor body 10 is uniformly arranged. The anti-demagnetization capacity and the efficiency of the motor can be improved under the condition that the structural strength of the motor can be guaranteed. Wherein Z is an auxiliary permanent magnet slot.

As shown in fig. 4 and 5, the auxiliary permanent magnet 30 has an arc-shaped structure, and the auxiliary permanent magnet 30 is disposed to be bent toward a magnetic pole center line of the rotor core. Alternatively, as shown in fig. 3, the auxiliary permanent magnets 30 are disposed to be bent away from the magnetic pole center line of the rotor core. The arrangement can also play a role in improving the demagnetization resistance of the motor.

In order to further improve the demagnetization resistance and efficiency of the motor, as shown in fig. 3, the central angle corresponding to the connection line of the shortest distance between the ends of the auxiliary permanent magnets 30 on the same magnetic pole, which are close to the outer edge of the rotor body 10, is K, wherein 0.3 ≧ K/J ≧ 0.1. The radian of the auxiliary permanent magnet 30 is L1, wherein the L1 is more than or equal to 85 degrees and less than or equal to 90 degrees.

As shown in fig. 6, 11, 12, 13, and 17, one end of the auxiliary permanent magnet slot close to the shaft hole 11 communicates with the main permanent magnet slot, and one end of the auxiliary permanent magnet slot close to the outer edge of the rotor body 10 is disposed at a distance from the main permanent magnet slot. There is not magnetic isolation bridge between the auxiliary permanent magnet inboard and the main permanent magnet groove, and the auxiliary permanent magnet is in the inboard magnetic leakage reduction, and then improves the flux linkage of motor, further guides the demagnetization magnetic field to walk to the rotor outside simultaneously for the inboard regional area of demagnetization of permanent magnet further reduces, thereby improves the anti demagnetization ability of main permanent magnet, and then improves the demagnetization ability of motor.

In order to further reduce the area of the demagnetization region, reduce the running current of the motor and reduce the copper loss of the motor, the maximum distance between the end part of the auxiliary permanent magnet 30 close to the shaft hole 11 and the outer edge of the main permanent magnet 20 close to the rotor body 10 is D1, the length of the main permanent magnet 20 in the radial direction of the rotor body 10 is C, wherein D1/C is less than or equal to 0.4. The long sides of the auxiliary permanent magnets 30 extend along the circumferential direction of the rotor body 10, the central angle formed by the connecting lines of the two ends of the auxiliary permanent magnets 30 and the shaft hole 11 is C1, the angle of the magnetic pole of the rotor body 10 is B1, wherein 0.3 is more than or equal to C1/B1 is more than or equal to 0.1.

As shown in FIG. 9, one end of the auxiliary permanent magnet slot facing the main permanent magnet slot is disposed at a distance from the main permanent magnet slot to form a third magnetic isolation bridge 14, and the width of the third magnetic isolation bridge 14 is F1, wherein 2 ≧ F1/≧ 1. The anti-demagnetization capacity and the efficiency of the motor can be improved under the condition that the structural strength of the rotor can be guaranteed.

Preferably, the thickness of the auxiliary permanent magnets 30 in the radial direction of the rotor body 10 is H1, where 0.4 ≧ H1/O ≧ 0.05. The arrangement can effectively improve the demagnetization resistance and efficiency of the motor.

An air groove 40 is formed between one end of the auxiliary permanent magnet 30 facing the center line of the magnetic pole and the auxiliary permanent magnet groove, a fourth magnetism isolating bridge 15 is formed between the air groove 40 and the outer edge of the rotor body 10, the thickness of the fourth magnetism isolating bridge 15 is G, and the G/0.8 is more than or equal to 1.8.

According to another embodiment of the present application, the auxiliary permanent magnet slots may be arranged to communicate with the main permanent magnet slots, and the communication may be either a middle communication or an end communication.

As shown in fig. 12, the auxiliary permanent magnets 30 located at both sides of the main permanent magnet 20 are different in length. As shown in fig. 11, the auxiliary permanent magnets 30 located at both sides of the center line of the same magnetic pole are symmetrically disposed about the center line of the magnetic pole. As shown at P in fig. 13, the auxiliary permanent magnets 30 located on both sides of the center line of the same magnetic pole are different in length.

According to another embodiment of the present application, the magnetic pole direction of the auxiliary permanent magnets 30 toward the outer edge of the rotor body 10 is the same as the magnetic pole direction of the rotor body 10. The magnetization direction of the main permanent magnets 20 is in the rotor circumferential direction, and the magnetization direction of the auxiliary permanent magnets 30 is in the rotor radial direction. The arrangement can effectively improve the demagnetization resistance and efficiency of the rotor structure. Preferably, the material of the main permanent magnet is ferrite, and the material of the auxiliary permanent magnet is neodymium iron boron.

The rotor structure in the above-mentioned embodiment can also be used for electrical equipment technical field, promptly according to the utility model discloses an on the other hand provides a motor, including rotor structure, rotor structure is the rotor structure in the above-mentioned embodiment.

Specifically, the rotor with the structure solves the problems of poor demagnetization resistance of the motor, low motor flux linkage and high running current, high copper consumption of the motor, low efficiency and easy demagnetization of the auxiliary permanent magnet in the prior art.

The application discloses rotor structure is a PMSM rotor structure, includes: rotor core, a plurality of tangential permanent magnet of n, follow rotor core's circumference sets up on rotor core to extend along rotor core's radial direction, the relative one side of per two adjacent tangential permanent magnet has the same polarity, wherein, the tangential permanent magnet is main permanent magnet, arrange supplementary permanent magnet on the magnetic pole that forms between main permanent magnet, supplementary permanent magnet is close to the main permanent magnet outside, leave the interval distance between the supplementary permanent magnet on the same magnetic pole, this distance shared angle is established to I, the central line contained angle of two adjacent main permanent magnets is established to J, I and J should satisfy following relation: the I/J is more than or equal to 0.08, the inner side of the auxiliary permanent magnet is closer to the main permanent magnet relative to the outer side, one side of the permanent magnet close to the shaft hole of the rotor core is the inner side of the permanent magnet, and one side of the permanent magnet close to the excircle of the rotor core is the outer side of the permanent magnet. The tangential permanent magnet motor adopts a magnetic circuit structure with single permanent magnets connected in parallel, the working point of a rotor permanent magnet is lower than that of a radial permanent magnet motor, the anti-demagnetization energy of the motor is poor, the auxiliary permanent magnets are arranged on the outer sides of the main permanent magnets, and the spacing distance is reserved between the auxiliary permanent magnets, so that the magnetic flux of the main permanent magnet is transmitted to an air gap without influencing the flux linkage of the motor, and meanwhile, the magnetic flux is used as a magnetic conduction channel to guide a demagnetization magnetic field to be transmitted to the auxiliary permanent magnets, the magnetic circuit trend of the demagnetization magnetic field is changed, the auxiliary permanent magnets guide the demagnetization magnetic field to move towards the outer side of the rotor, the size of the demagnetization magnetic field born by the main permanent magnet is reduced, the working point of the tangential main permanent.

Furthermore, a distance is reserved between the two auxiliary permanent magnets, so that the main permanent magnet can provide magnetic flux for an air gap conveniently, the motor flux linkage is improved, the running current is reduced, and further the copper consumption is reduced, so that the I/J is more than or equal to 0.0.08, but when the I/J is more than 0.3, the magnetic field of the auxiliary permanent magnet acts on the main permanent magnet more, the demagnetization of the main permanent magnet is increased, and the demagnetization resistance of the motor is reduced.

An auxiliary permanent magnet is arranged on one side of the main permanent magnet, which provides magnetic flux, the opposite side of the auxiliary permanent magnet and the main permanent magnet has the same polarity, namely the magnetizing direction of the auxiliary permanent magnet is opposite to that of the main permanent magnet, the magnetizing direction of the auxiliary permanent magnet is opposite to that of a rotor magnetic pole, the auxiliary permanent magnet extends along the radial direction of the rotor, the auxiliary permanent magnet is close to the outer side of the main permanent magnet, the opposite outer side of the inner side of the auxiliary permanent magnet is closer to the main permanent magnet, the inner side of the permanent magnet, which is close to a shaft hole of a rotor core, is the inner side of the permanent magnet, the outer side of the permanent magnet, which is close to the excircle of the rotor core, is the outer side of the permanent magnet, the opposite side of the auxiliary permanent magnet and the main permanent magnet has the same polarity setting, the magnetic path trend, the auxiliary permanent magnet is inclined relative to the main permanent magnet, the auxiliary permanent magnet does not bear a demagnetization magnetic field, and the auxiliary permanent magnet is not easy to demagnetize.

The inner side of the auxiliary permanent magnet is closer to the main permanent magnet relative to the outer side, the auxiliary permanent magnet is inclined relative to the central line of the main permanent magnet, an included angle A is formed between the central line of the auxiliary permanent magnet and the central line of the main permanent magnet, and the optimal value range of A is as follows: a is more than or equal to 70 degrees and more than or equal to 20 degrees, if A is less than 20 degrees, the magnetic fields of the auxiliary permanent magnet and the main permanent magnet are opposite and have a small included angle, the magnetic field of the auxiliary permanent magnet can increase the demagnetization of the main permanent magnet, so that the magnetic density in the demagnetization area of the main permanent magnet is lower, the demagnetization resistance of the motor is reduced, A is more than 70 degrees, the auxiliary permanent magnet has little influence on the improvement of the demagnetization effect, the using amount of the permanent magnet can be increased on the contrary, the cost of the permanent magnet is improved, and the effect is optimal when A is more than or.

The auxiliary permanent magnet is close to the outer side of the main permanent magnet, the distance between the inner side of the auxiliary permanent magnet and the outer side of the main permanent magnet is set as B, the radial length of the main permanent magnet is set as C, and B and C should satisfy the following relations: 0.18 is more than or equal to B/C, the additional auxiliary permanent magnet can guide the demagnetizing field to move to the outer side of the rotor, but the auxiliary permanent magnet also has a magnetic field for demagnetizing the main permanent magnet, when the B/C is more than 0.18, the change of the area of the demagnetizing area at the outer side of the main permanent magnet is smaller, and when the demagnetizing field is smaller, the demagnetizing rate of the motor is increased on the contrary, so that the B/C is more than or equal to 0.18, the area of the demagnetizing area at the inner side of the main permanent magnet is reduced, and the area of the demagnetizing area at the outer side.

The auxiliary permanent magnet is close to the excircle of the rotor core, a distance is reserved between the auxiliary permanent magnet and the excircle of the rotor core, the distance is set to be F, the length of an air gap between the stator and the rotor of the motor is set to be F, and the ratio of F/satisfies the following relation: the auxiliary permanent magnet provides magnetic flux for the air gap when the frequency is more than or equal to 1.5F/> 1, when the frequency is less than 1, the auxiliary permanent magnet is close to the excircle of the rotor and is not beneficial to punching a rotor iron core die, the processing process of the rotor is complex, so the frequency is more than or equal to 1, when the frequency is more than 1.5, the magnetic flux leakage of the auxiliary permanent magnet is increased, the utilization rate of the permanent magnet is reduced, and therefore the frequency is more than or equal to 1.5.

The thickness of the auxiliary permanent magnet is smaller than that of the main permanent magnet, the thickness of the auxiliary permanent magnet is set to be D, the thickness of the main permanent magnet is set to be O, and the ratio of D/O satisfies the following relation: D/O is more than or equal to 0.4 and more than or equal to 0.05. Simulation research finds that if the main permanent magnet is in a failure mode, when the D/O is larger than 0.4mm, the thickness of the auxiliary permanent magnet is increased, the auxiliary permanent magnet generates a demagnetizing field, the composite demagnetizing field borne by the main permanent magnet is increased when the main permanent magnet acts on the main permanent magnet, the demagnetizing rate of the main permanent magnet is improved, the demagnetization resistance of the motor is reduced, when the D/O is smaller than 0.05, the improvement on demagnetization is not obvious, when the D/O is larger than or equal to 0.4, the auxiliary permanent magnet mainly acts on changing the trend of a magnetic circuit of the demagnetizing field, guiding the direction of the demagnetizing field, and the thickness of the auxiliary permanent magnet is not large, the auxiliary permanent magnet is obliquely arranged relative to the main permanent magnet, the demagnetization effect on the main permanent magnet is small, and the demagnetizing area of the main permanent magnet is concentrated at the corner position of the outer side, under the design, the area of the inner side of the main permanent magnet is reduced, and the, and meanwhile, the area of a demagnetization area at the outer side of the main permanent magnet is reduced, so that the demagnetization resistance of the motor is improved.

The coercive force of the auxiliary permanent magnet is higher than that of the main permanent magnet, the remanence of the auxiliary permanent magnet is higher than that of the main permanent magnet, for example, the main permanent magnet is made of ferrite, and the auxiliary permanent magnet is made of neodymium iron boron. The ferrite is low in price, the neodymium iron boron is high in price, two magnetic materials are used, the main permanent magnet is the ferrite, the cost of the whole motor can be reduced, meanwhile, the outer auxiliary permanent magnet is the neodymium iron boron, the auxiliary permanent magnet provides magnetic flux for an air gap, the flux linkage of the motor is improved, the running current of the motor is reduced, and the copper consumption of the motor is reduced.

The main permanent magnet and the auxiliary permanent magnet can also be made of the same material, for example, the main permanent magnet and the auxiliary permanent magnet are both ferrite, or the main permanent magnet and the auxiliary permanent magnet are both neodymium iron boron.

The auxiliary permanent magnet is arranged in the auxiliary permanent magnet groove, a section of distance is reserved between the outer side of the auxiliary permanent magnet groove and the outer circle of the rotor core, a magnetic isolation bridge 1 is formed, the thickness of each part of the magnetic isolation bridge 1 is uniform, the magnetic leakage of the auxiliary permanent magnet is reduced, the utilization rate of the permanent magnet is improved, a section of distance is reserved between the inner side of the auxiliary permanent magnet groove and the main permanent magnet groove, a magnetic isolation bridge 2 is formed, the thickness of each part of the magnetic isolation bridge 2 is uniform, the magnetic leakage of the auxiliary permanent magnet is reduced, the utilization rate of the permanent magnet is improved, the magnetic flux of the motor is improved, meanwhile, the auxiliary permanent magnet is designed into a.

The auxiliary permanent magnets are arc-shaped, the auxiliary permanent magnets are bent towards the central line of the magnetic pole, a distance is reserved between the two auxiliary permanent magnets on the same magnetic pole, the angle occupied by the distance is set to be K, the included angle of the central lines of the two adjacent main permanent magnets is set to be J, and the K and the J meet the following relation: K/J is more than or equal to 0.3 and more than or equal to 0.1, and the processing cost of the flat permanent magnet is high, so that the arc permanent magnet is changed into the flat permanent magnet, the processing cost of the permanent magnet can be reduced, the cost of the motor is reduced, and the cost performance of the motor is improved.

The auxiliary permanent magnet is arc-shaped, the auxiliary permanent magnet is bent towards the central line of the main permanent magnet, a distance is reserved between two auxiliary permanent magnets on the same magnetic pole, the angle occupied by the distance is set as M, the included angle of the central lines of two adjacent main permanent magnets is set as J, and the M and the J meet the following relation: M/J is more than or equal to 0.3 and more than or equal to 0.1, and the processing cost of the flat permanent magnet is high, so that the arc permanent magnet is changed into the flat permanent magnet, the processing cost of the permanent magnet can be reduced, the cost of the motor is reduced, and the cost performance of the motor is improved.

The auxiliary permanent magnet groove is arc-shaped, the auxiliary permanent magnet groove is bent towards the central line of the main permanent magnet, a magnetic isolation bridge is reserved between the auxiliary permanent magnet groove and the outer circle of the rotor core, the thickness of each magnetic isolation bridge is uniform, the auxiliary permanent magnet is arranged in the auxiliary permanent magnet groove, the included angle between the side edge of the auxiliary permanent magnet and the arc surface is close to 90 degrees, the two side edges are parallel, the sharp angle of the magnetic steel is reduced, the rigidity of the magnetic steel is improved, the fracture of the magnetic steel corner of the motor in the operation process is prevented, the performance of the motor.

The auxiliary permanent magnet groove inner side is communicated with the main permanent magnet groove, a magnetic isolation bridge is not arranged between the auxiliary permanent magnet inner side and the main permanent magnet groove, the magnetic leakage of the auxiliary permanent magnet in the inner side is reduced, and then the flux linkage of the motor is improved, and meanwhile, a demagnetization magnetic field is further guided to move towards the outer side of the rotor, so that the demagnetization area of the permanent magnet inner side is further reduced, the demagnetization resistance of the main permanent magnet is improved, and the demagnetization capacity of the motor is further improved.

The main permanent magnets are tangential permanent magnets, auxiliary permanent magnets are arranged on rotor magnetic poles formed between the adjacent main permanent magnets, one side of each auxiliary permanent magnet is close to the main permanent magnet, the other side of each auxiliary permanent magnet is close to the central line of the rotor magnetic pole, and the direction of the auxiliary permanent magnet towards the magnetic pole on the outer side of the rotor is the same as the direction of the rotor magnetic pole. One side of the permanent magnet close to the shaft hole of the rotor core is the inner side of the permanent magnet, and one side of the permanent magnet close to the excircle of the rotor core is the outer side of the permanent magnet. The auxiliary permanent magnet is arranged on the outer side of the main permanent magnet, the direction of the magnetic pole of the auxiliary permanent magnet is the same as that of the magnetic pole of the rotor, the trend of a magnetic circuit of a demagnetizing field can be changed, the auxiliary permanent magnet guides the demagnetizing field to move towards the outer side of the rotor, the size of the demagnetizing field borne by the main permanent magnet is reduced, the working point of the tangential main permanent magnet is improved, the areas of demagnetizing areas on the outer side and the inner side of the tangential permanent magnet are reduced, the demagnetization resistance of the motor is improved, the auxiliary permanent magnet does not bear the demagnetizing field.

The auxiliary permanent magnet is positioned on the outer side of the main permanent magnet, the auxiliary permanent magnet is positioned on the outer side of the rotor, the distance between the inner side of the auxiliary permanent magnet and the outer side of the main permanent magnet is set to be D1, the length of the main permanent magnet is set to be C, and D1 and C should satisfy the following relations: D1/C is less than or equal to 0.4, the additional auxiliary permanent magnet can guide the demagnetization magnetic field to move to the outer side of the rotor, the more the auxiliary permanent magnet tends to the outer side of the rotor, the less the demagnetization magnetic field is transmitted to the inner side of the rotor, the smaller the demagnetization magnetic field born by the main permanent magnet is, the inner side demagnetization area of the main permanent magnet is reduced, and the demagnetization area of the outer side of the main permanent magnet is also reduced, when D1/C is more than 0.4, although the demagnetization area of the inner side of the main permanent magnet is reduced, the demagnetization area of the outer side of the main permanent magnet is increased, and the demagnetization resistance of the motor is not improved.

The auxiliary permanent magnet extends along the circumferential direction of the rotor, a section of length is arranged along the circumferential direction of the rotor, the angle occupied by the section of length is set as C, the angle occupied by the magnetic pole of the rotor is set as B, and C and B meet the following relation that C/B is more than or equal to 0.1.

The longer the auxiliary permanent magnet extends along the circumferential direction of the rotor, the more the auxiliary permanent magnet guides the demagnetizing field to conduct to the outer side of the rotor, so that C/B is larger than or equal to 0.1, but the longer the auxiliary permanent magnet is, the shorter the magnetic conduction channel between the auxiliary permanent magnets is, the easier the magnetic conduction channel is saturated, the less the magnetic flux transferred to the air gap by the main permanent magnet is, the utilization rate of the main permanent magnet is reduced, and so that C/B is larger than or equal to 0.3.

A distance is reserved between the auxiliary permanent magnet and the main permanent magnet, namely, a middle bridge connected with a rotor iron core is arranged between the auxiliary permanent magnet and the main permanent magnet, the width of the middle bridge is set to be F, the length of an air gap between a stator and a rotor of the motor is set to be F1/the ratio of the F1/should satisfy the following relation: 2 is more than or equal to F1/> or equal to 1, in order to prevent the main permanent magnet from flying out when running at high speed, the outer side of the main permanent magnet is provided with a protective wall, an intermediate bridge is arranged between the auxiliary permanent magnet and the main permanent magnet, the centrifugal force acted on the protective wall when the magnetic steel rotates at high speed can be reduced, the structural strength of the rotor is improved, and the reliability of the motor is improved, so that F1/> or equal to 1, but when the width of the intermediate bridge is too wide, a demagnetization magnetic field can act on the main permanent magnet from the intermediate bridge, so that the area of a demagnetization area of the main permanent magnet is increased, the demagnetization resistance of the main permanent magnet is poor, the demagnetization resistance of the motor is reduced, and.

The auxiliary permanent magnet has a certain thickness in the radial direction of the rotor, the thickness of the auxiliary permanent magnet is smaller than that of the main permanent magnet, the thickness of the auxiliary permanent magnet is set to be H, the thickness of the main permanent magnet is set to be O, and the ratio of H1/O satisfies the following relation: 0.4. gtoreq.H 1/O. gtoreq.0.05. The thicker the auxiliary permanent magnet is, the stronger the magnetism of the auxiliary permanent magnet is, the stronger the ability of guiding the trend of the demagnetization magnetic field is, so H1/O is more than or equal to 0.05, but after the auxiliary permanent magnet reaches a certain thickness, the ability of guiding the demagnetization magnetic field is not increased basically, the thickness of the auxiliary permanent magnet is increased, the using amount of the permanent magnet is increased, the cost of the motor is increased, and the cost performance of the motor is reduced.

An air groove is formed in one side, close to the center line of the magnetic pole, of the auxiliary permanent magnet, a magnetic isolation bridge is formed between the air groove and the outer circle of the rotor core, the thickness of the magnetic isolation bridge is set to be G, the length of an air gap between the stator and the rotor of the motor is set to be G/G, and the ratio of G/G is required to meet the following relation: 1.8 is more than or equal to G/> 0.8. The air slot is arranged on one side of the auxiliary permanent magnet close to the center line of the magnetic pole, a magnetic isolation bridge is formed between the air slot and the outer circle of the rotor core, the magnetic isolation part at the end part of the auxiliary permanent magnet can be prolonged, the end part magnetic leakage of the auxiliary permanent magnet is reduced, the magnetic flux conducted from the demagnetization magnetic field guided by the auxiliary permanent magnet to the outer side of the rotor is improved, the magnetic circuit is changed, the working point of the main permanent magnet is improved, the demagnetization area of the inner side and the outer side of the main permanent magnet is reduced, and the demagnetization resistance of the.

The auxiliary permanent magnet groove is communicated with the main permanent magnet groove, a middle bridge reserved between the auxiliary permanent magnet and the main permanent magnet groove can allow a small part of demagnetizing magnetic field to act on the main permanent magnet through the middle bridge, the two permanent magnet grooves are communicated, the demagnetizing magnetic field borne by the main permanent magnet is reduced, the optimal position is arranged on one side, close to the main permanent magnet, of the auxiliary permanent magnet, and the effect of the auxiliary permanent magnet in a demagnetizing magnetic circuit can be exerted to the maximum degree.

The auxiliary permanent magnets on the rotor magnetic poles are different in circumferential length, the auxiliary permanent magnets on the left side and the right side of the main permanent magnet are different in circumferential length, and the length of the shorter auxiliary permanent magnet is more than half of the length of the longer auxiliary permanent magnet. The permanent magnets with unequal lengths are arranged, so that the demagnetization capability of the motor is improved, the using amount of the auxiliary permanent magnets can be reduced, the cost of the permanent magnets is reduced, and the cost performance of the motor is improved.

The auxiliary permanent magnets on the rotor magnetic poles are different in circumferential length, the auxiliary permanent magnets on the left side and the right side of the main permanent magnet are equal in circumferential length, the auxiliary permanent magnets on the left side and the right side of the main permanent magnet are symmetrical with respect to the center line of the main permanent magnet, and the length of the shorter auxiliary permanent magnet is more than half of the length of the longer auxiliary permanent magnet. The auxiliary permanent magnets on the left side and the right side of the main permanent magnet are equal in circumferential length, so that the demagnetization capacity of the motor is improved, the using amount of the auxiliary permanent magnets can be reduced, the cost of the permanent magnets is reduced, the magnetic poles of the motor are more symmetrical, the torque pulsation of the motor is reduced, the operation stability of the motor is improved, and the cost performance of the motor is further improved.

The coercive force of the auxiliary permanent magnet is higher than that of the main permanent magnet, the remanence of the auxiliary permanent magnet is higher than that of the main permanent magnet, if the main permanent magnet is made of ferrite, the auxiliary permanent magnet is made of neodymium iron boron, the magnetic force of the neodymium iron boron is stronger than that of the ferrite, the main permanent magnet is made of ferrite with low magnetic performance, the permanent magnet which plays a role in guiding a demagnetizing field, namely the auxiliary permanent magnet, is made of neodymium iron boron with high magnetic performance, and the neodymium iron boron is not used at the same time, so that the utilization rate of.

As shown in fig. 10, a protective wall structure T is formed on the outer sides of the main permanent magnet and the auxiliary permanent magnet, where Y in fig. 11 is a communication part, M in fig. 12 and 13 is the length of one of the auxiliary permanent magnets, and N is the length of the auxiliary permanent magnet adjacent to the auxiliary permanent magnet and located on the same magnetic pole. The length of M is more than half of N. Reference numeral 50 in fig. 8 denotes a stator.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition to the foregoing, it should be noted that reference throughout this specification to "one embodiment," "another embodiment," "an embodiment," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment described generally throughout this application. The appearances of the same phrase in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the scope of the invention to effect such feature, structure, or characteristic in connection with other embodiments.

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (28)

1. A rotor structure, comprising:

the permanent magnet rotor comprises a rotor body (10), wherein a plurality of main permanent magnet grooves are formed in the rotor body (10), auxiliary permanent magnet grooves are formed in two side edges of each main permanent magnet groove, extending along the radial direction of the rotor body (10), a main permanent magnet (20) is arranged in each main permanent magnet groove, and an auxiliary permanent magnet (30) is arranged in each auxiliary permanent magnet groove;

the distances between the auxiliary permanent magnet grooves on two sides of the same main permanent magnet groove are gradually increased outwards along the radial direction of the rotor body (10).

2. The rotor structure according to claim 1, wherein a first end of the main permanent magnet slot is disposed near a shaft hole (11) of the rotor body (10), a second end of the main permanent magnet slot is disposed far from the shaft hole (11) along a radial direction of the rotor body (10), a first end of the auxiliary permanent magnet slot is disposed near the shaft hole (11), a second end of the auxiliary permanent magnet slot is disposed far from the shaft hole (11), and a plane where an end surface of the second end of the main permanent magnet slot is located intersects with the auxiliary permanent magnet slot.

3. The rotor structure according to claim 1, characterized in that the central angle corresponding to the line between the ends of the auxiliary permanent magnets (30) on the same magnetic pole close to the outer edge of the rotor body (10) is I, and the central angle formed between the geometric centerlines of two adjacent main permanent magnets (20) is J, wherein I/J is more than or equal to 0.08.

4. The rotor structure of claim 3, wherein I/J is 0.3 or less.

5. Rotor structure according to claim 1, characterised in that the side of the auxiliary permanent magnet (30) opposite to the main permanent magnet (20) has the same polarity.

6. The rotor structure according to claim 1, characterized in that the auxiliary permanent magnets (30) are strip-shaped, and the geometric center line of the auxiliary permanent magnets (30) in the long side direction forms an included angle A with the geometric center line of the main permanent magnet slot, wherein 70 ° ≧ A ≧ 20 °.

7. The rotor structure according to claim 1, characterized in that the maximum distance between the end of the auxiliary permanent magnet (30) on the side close to the shaft hole (11) and the outer edge of the main permanent magnet (20) close to the rotor body (10) is B, and the length of the main permanent magnet (20) in the radial direction of the rotor body (10) is C, wherein 0.18 ≧ B/C.

8. The rotor structure according to claim 1, characterized in that the minimum distance between the end of the auxiliary permanent magnet (30) on the side close to the outer edge of the rotor body (10) and the outer edge of the rotor body (10) is F, wherein 1.5 ≧ F/≧ 1, which is the air gap length between the stator and the rotor body (10).

9. Rotor structure according to claim 1, characterized in that the thickness of the auxiliary permanent magnets (30) is D and the thickness of the rotor body (10) is O, wherein 0.4 ≧ D/O ≧ 0.05.

10. Rotor structure according to claim 1, characterized in that the coercive force of the auxiliary permanent magnet (30) is higher than the coercive force of the main permanent magnet (20).

11. A rotor structure according to claim 1, characterized in that the end of the auxiliary permanent magnet slot on the side away from the shaft hole (11) is arranged with a distance to the outer edge of the rotor body (10) to form a first flux barrier (12), the thickness of the first flux barrier (12) in the radial direction of the rotor body (10) being arranged uniformly.

12. A rotor structure according to claim 1 or 11, characterized in that the end of the auxiliary permanent magnet slot on the side close to the shaft hole (11) is arranged with a distance from the main permanent magnet slot to form a second magnetic isolation bridge (13), the thickness of the second magnetic isolation bridge (13) in the radial direction of the rotor body (10) being arranged uniformly.

13. The rotor structure according to claim 1, characterized in that the auxiliary permanent magnets (30) are arc-shaped structures, and the auxiliary permanent magnets (30) are arranged curved towards the pole centre line of the rotor core, or the auxiliary permanent magnets (30) are arranged curved away from the pole centre line of the rotor core.

14. The rotor structure according to claim 13, characterized in that the circle center angle corresponding to the connection line of the shortest distance between the ends of the auxiliary permanent magnets (30) on the same magnetic pole close to the outer edge of the rotor body (10) is K, and the circle center angle formed between the geometric center lines of two adjacent main permanent magnets (20) is J, wherein 0.3 ≧ K/J ≧ 0.1.

15. The rotor structure according to claim 13, characterized in that the arc of the auxiliary permanent magnets (30) is L1, wherein 85 ° ≦ L1 ≦ 90 °.

16. A rotor structure according to claim 1, characterised in that the end of the auxiliary permanent magnet slot close to the shaft hole (11) communicates with the main permanent magnet slot, the end of the auxiliary permanent magnet slot close to the outer edge of the rotor body (10) being arranged at a distance from the main permanent magnet slot.

17. The rotor structure according to claim 13, characterized in that the maximum distance between the end of the auxiliary permanent magnet (30) on the side close to the shaft hole (11) and the main permanent magnet (20) on the outer edge close to the rotor body (10) is D1, the length of the main permanent magnet (20) in the radial direction of the rotor body (10) is C, wherein D1/C ≦ 0.4.

18. The rotor structure according to claim 1, wherein the long side of the auxiliary permanent magnet (30) extends along the circumferential direction of the rotor body (10), the central angle formed by the connecting line of the two ends of the auxiliary permanent magnet (30) and the shaft hole (11) is C1, the angle of the magnetic pole of the rotor body (10) is B1, wherein 0.3 ≧ C1/B1 ≧ 0.1.

19. Rotor structure according to claim 18, characterised in that the end of the auxiliary permanent magnet slot facing the main permanent magnet slot is arranged at a distance from the main permanent magnet slot to form a third magnetic isolation bridge (14), the width of the third magnetic isolation bridge (14) being F1, where 2 ≧ F1/≧ 1, which is the air gap length between stator and rotor body (10).

20. Rotor structure according to claim 18, characterized in that the thickness of the auxiliary permanent magnets (30) in the radial direction of the rotor body (10) is H1, where 0.4 ≧ H1/O ≧ 0.05, and the thickness of the main permanent magnet (20) is set to O.

21. The rotor structure according to claim 18, characterized in that an air slot (40) is formed between one end of the auxiliary permanent magnet (30) facing the center line of the magnetic pole and the auxiliary permanent magnet slot, a fourth magnetic isolation bridge (15) is formed between the air slot (40) and the outer edge of the rotor body (10), the thickness of the fourth magnetic isolation bridge (15) is G, wherein 1.8 ≧ G/≧ 0.8 is the air gap length between the stator and the rotor body (10).

22. The rotor structure of claim 18, wherein the auxiliary permanent magnet slots are in communication with the main permanent magnet slots.

23. Rotor structure according to claim 18, characterised in that the length of the auxiliary permanent magnets (30) on both sides of the main permanent magnet (20) is different.

24. Rotor structure according to claim 1 or 23, characterised in that the auxiliary permanent magnets (30) located on both sides of the centre line of the same pole are arranged symmetrically with respect to the centre line of the pole.

25. Rotor structure according to claim 18, characterised in that the length of the auxiliary permanent magnets (30) on both sides of the centre line of the same pole is different.

26. The rotor structure according to claim 1, characterized in that the outer edge pole direction of the auxiliary permanent magnets (30) towards the rotor body (10) is the same as the pole direction of the rotor body (10).

27. The rotor structure according to claim 1, characterized in that the main permanent magnets (20) are magnetized in a circumferential direction of the rotor body (10) and the auxiliary permanent magnets (30) are magnetized in a radial direction of the rotor body (10).

28. An electrical machine comprising a rotor structure, characterized in that the rotor structure is as claimed in any one of claims 1 to 27.

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