Permanent magnet synchronous motor rotor and permanent magnet motor

Abstract

The application provides a permanent magnet synchronous motor rotor and a permanent magnet motor, and the permanent magnet synchronous motor rotor comprises a rotor core and tangential permanent magnets, and the opposite sides of every two adjacent tangential permanent magnets have the same polarity; the tangential permanent magnets comprise main permanent magnets and auxiliary permanent magnets, the main permanent magnets are located at the radial outer side of the auxiliary permanent magnets, and the auxiliary permanent magnets are inclined relative to the main permanent magnets, namely, the center line of the auxiliary permanent magnet is not parallel to and not on the same straight line as the center line of the main permanent magnet, there is an included angle A between the center lines of the two magnets, the included angle between the center lines of two adjacent main permanent magnets is B, and A and B satisfy the following relationship: A / B>=0.06.According to the application, the angle between the auxiliary permanent magnet and the armature magnetic field magnetic line can be increased, the area of the auxiliary permanent magnet in the limited space is increased, the demagnetization rate of the auxiliary permanent magnet is reduced, the contact area between the auxiliary permanent magnet and the main permanent magnet is reduced, the demagnetization effect on the main permanent magnet is reduced, and the anti-demagnetization capability of the motor is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular to a permanent magnet synchronous motor rotor and a permanent magnet motor. BACKGROUND

[0002] The motor with tangential magnetization structure of permanent magnets can generate higher air gap flux density than the motor with radial magnetization structure of permanent magnets due to the "magnetic aggregation" effect, so that the motor has larger torque / current ratio and torque / volume ratio, and is increasingly applied to servo systems, electric traction, office automation, household appliances and other occasions.

[0003] The prior art tangential permanent magnet motor adopts a magnetic circuit structure with a single permanent magnet in parallel, so that the working point of the rotor permanent magnet is lower than that of the radial permanent magnet motor, which can easily cause the motor efficiency to decrease, and there is a risk of demagnetization in a harsh environment, so that the motor cannot operate.

[0004] Since the prior art permanent magnet motor has the problems of poor anti-demagnetization capability, low motor flux linkage, large operating current, large motor copper loss, low efficiency, and easy demagnetization of the auxiliary permanent magnet, the present application provides a permanent magnet synchronous motor rotor and a permanent magnet motor. SUMMARY

[0005] Therefore, the present application aims to overcome the defects of the prior art permanent magnet motor, such as poor anti-demagnetization capability, and to provide a permanent magnet synchronous motor rotor and a permanent magnet motor.

[0006] In order to solve the above problems, the present application provides a permanent magnet synchronous motor rotor, which comprises a rotor core and a tangential permanent magnet, wherein the tangential permanent magnet is arranged on the rotor core to extend along the radial direction of the rotor core, the tangential permanent magnet is N in number, N≥2, and the N tangential permanent magnets are arranged in sequence along the circumferential direction of the rotor core, and each two adjacent tangential permanent magnets have the same polarity on the side facing each other.

[0007] The tangential permanent magnet comprises a main permanent magnet and an auxiliary permanent magnet, the main permanent magnet is located radially outward of the auxiliary permanent magnet, the auxiliary permanent magnet is inclined relative to the main permanent magnet, i.e. the auxiliary permanent magnet center line of the auxiliary permanent magnet is not parallel to and not on the same straight line as the main permanent magnet center line of the main permanent magnet, and there is an included angle between the auxiliary permanent magnet center line and the main permanent magnet center line.

[0008] The included angle is denoted as A, the included angle of the magnet center lines of two adjacent main permanent magnets is denoted as B, and A and B satisfy the following relationship: A / B≥0.06.

[0009] In some embodiments, A and B also satisfy the following relationship: A / B≤0.4.

[0010] In some embodiments, the secondary permanent magnet is a rectangular permanent magnet, and a projection of the secondary permanent magnet on an end surface of the rotor core is a rectangle.

[0011] In some embodiments, in the same tangential permanent magnet, the magnetization direction of the primary permanent magnet is along the circumferential direction of the rotor, the magnetization direction of the secondary permanent magnet is along the circumferential direction of the rotor, and the included angle between the magnetization direction of the primary permanent magnet and the magnetization direction of the secondary permanent magnet is C, and C≤30°.

[0012] In some embodiments, the magnetization direction of the secondary permanent magnet is perpendicular to the magnet center line of the secondary permanent magnet, and the magnetization direction of the primary permanent magnet is perpendicular to the magnet center line of the primary permanent magnet.

[0013] In some embodiments, between two adjacent tangential permanent magnets constituting one magnetic pole, the secondary permanent magnet of one of the tangential permanent magnets is inclined to a first direction relative to the primary permanent magnet connected thereto, and the secondary permanent magnet of the other tangential permanent magnet is inclined to a second direction relative to the primary permanent magnet connected thereto, the first direction being opposite to the second direction; the minimum distance between the radially outer ends of the two adjacent secondary permanent magnets of one pole is E, the minimum distance between the radially outer ends of the two adjacent secondary permanent magnets of another pole is F, and the ratio of E / F satisfies the following relationship: 1.4≥E / F≥0.8.

[0014] In some embodiments, the lengths of the two adjacent secondary permanent magnets in the rotor radial direction are not equal, one of the lengths is G, and the other of the lengths is H, and the ratio of G / H should satisfy the following relationship: 1.5≥G / H≥1.

[0015] In some embodiments, the coercive force of the secondary permanent magnet is higher than the coercive force of the primary permanent magnet, that is, the residual magnetism of the secondary permanent magnet is higher than the residual magnetism of the primary permanent magnet.

[0016] In some embodiments, the material of the primary permanent magnet is ferrite, and the material of the secondary permanent magnet is neodymium iron boron.

[0017] The application also provides a permanent magnet synchronous motor rotor comprising the permanent magnet synchronous motor rotor as claimed in any one of the preceding claims.

[0018] The permanent magnet synchronous motor rotor and the permanent magnet motor provided by the application have the following beneficial effects:

[0019] This invention employs a secondary permanent magnet outside the main permanent magnet. The secondary permanent magnet is tilted relative to the main permanent magnet, and their center lines are not on the same straight line, with an angle A between them. The angle between the center lines of two adjacent main permanent magnets is set to B, where A / B ≥ 0.06. This effectively increases the angle between the secondary permanent magnet and the armature magnetic field lines. Simultaneously, it increases the area of ​​the secondary permanent magnet within a limited space, reducing its demagnetization rate and the contact area between it and the main permanent magnet, thus reducing the demagnetizing effect on the main permanent magnet. This improves the motor's resistance to demagnetization. Furthermore, the secondary permanent magnet provides magnetic flux to the air gap, increasing the motor's flux linkage, reducing the operating current, lowering copper losses, and improving motor efficiency. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the novel tangential motor rotor structure of the present invention. Figure 1 ;

[0021] Figure 2 This is a schematic diagram of the novel tangential motor rotor structure of the present invention. Figure 2 ;

[0022] Figure 3 This is a schematic diagram of the novel tangential motor rotor structure of the present invention. Figure 3 ;

[0023] Figure 4 This is a schematic diagram of the novel tangential motor structure of the present invention;

[0024] Figure 5 This is a comparison diagram of the demagnetization rate of permanent magnets in the novel tangential motor of the present invention and that in existing motors;

[0025] Figure 6 This is a comparison diagram of the magnetic flux linkage between the novel tangential motor of the present invention and an existing motor;

[0026] Figure 7 This is a comparison diagram of the demagnetizing current of the novel tangential motor of the present invention and an existing motor.

[0027] The reference numerals in the attached figures are as follows:

[0028] 1. Rotor core; 2. Tangential permanent magnet; 21. Main permanent magnet; 22. Secondary permanent magnet; 23. Center line of main permanent magnet; 24. Center line of secondary permanent magnet; 3. Rivet hole; 4. Stator; 41. Stator slot; 42. Slot opening; 43. Gap. Detailed Implementation

[0029] like Figures 1-7As shown, the application provides a permanent magnet synchronous motor rotor, which comprises a rotor core 1 and a tangential permanent magnet 2 (tangential permanent magnet refers to the magnetization direction along the circumferential direction of the position (with the rotor core as a circle)), the tangential permanent magnet 2 (preferably a spoke type permanent magnet) is arranged on the rotor core and extends along the radial direction of the rotor core, the tangential permanent magnet is N, N≥2, and the N tangential permanent magnets 2 are arranged in sequence along the circumferential direction of the rotor core 1, and the opposite sides of every two adjacent tangential permanent magnets 2 have the same polarity;

[0030] Wherein, the tangential permanent magnet 2 comprises a main permanent magnet 21 and a secondary permanent magnet 22, the main permanent magnet 21 is located on the radial outer side of the secondary permanent magnet 22, the secondary permanent magnet 22 is inclined relative to the main permanent magnet 21, that is, the secondary permanent magnet center line 24 of the secondary permanent magnet is not parallel to and not on the same straight line as the main permanent magnet center line 23 of the main permanent magnet, and there is an included angle between the secondary permanent magnet center line 24 and the main permanent magnet center line 23;

[0031] The included angle is A, the included angle can be on the counterclockwise side of the main permanent magnet center line, or on the clockwise side of the main permanent magnet center line, the included angle between the main permanent magnet center lines 23 of two adjacent main permanent magnets is B, and A and B satisfy the following relationship: A / B≥0.06.

[0032] The application adopts a secondary permanent magnet on the outer side of the main permanent magnet, the secondary permanent magnet is inclined relative to the main permanent magnet, the magnet center line of the secondary permanent magnet is not on the same straight line as the magnet center line of the main permanent magnet, there is an included angle A between the two magnet center lines, and the included angle between the magnet center lines of two adjacent main permanent magnets is B, and A / B≥0.06; the angle between the secondary permanent magnet and the armature magnetic field magnetic force line can be effectively increased, the area of the secondary permanent magnet in the limited space is increased, the demagnetization rate of the secondary permanent magnet is reduced, the contact area between the secondary permanent magnet and the main permanent magnet is reduced, the demagnetization effect on the main permanent magnet is reduced, thereby the anti-demagnetization ability of the motor is improved, the secondary permanent magnet provides magnetic flux to the air gap, the magnetic chain of the motor is improved, the operating current of the motor is reduced, the copper loss of the motor is reduced, and the efficiency of the motor is improved.

[0033] The application provides a permanent magnet synchronous motor rotor, which comprises a rotor core, N tangential spoke type permanent magnets arranged on the rotor core along the circumferential direction of the rotor core and extending along the radial direction of the rotor core, and the opposite sides of every two adjacent tangential permanent magnets have the same polarity, wherein the tangential spoke type permanent magnet is composed of at least two sections, the section close to the shaft side is a main permanent magnet, a secondary permanent magnet is arranged outside the main permanent magnet, the secondary permanent magnet is close to the outer circle of the rotor, the secondary permanent magnet is inclined relative to the main permanent magnet, the center line of the two magnets is not on the same straight line, and an included angle between the two center lines is provided; the angle of the included angle is A, the included angle can be on the counterclockwise side of the center line of the main permanent magnet or on the clockwise side of the center line of the main permanent magnet, the included angle between the center lines of two adjacent main permanent magnets is B, and A and B should satisfy the following relationship: A / B>=0.06.

[0034] The spoke type permanent magnet motor adopts the magnetic circuit structure of parallel connection of single permanent magnet, the working point of the rotor permanent magnet is lower than that of the radial permanent magnet motor, the motor has poor anti-demagnetization capacity, the secondary permanent magnet is arranged outside the main permanent magnet, the secondary permanent magnet is close to the outer circle of the rotor, the secondary permanent magnet is inclined, the use amount of the permanent magnet is increased in the limited space, the demagnetization effect of the armature magnetic field on the secondary permanent magnet is reduced, the demagnetization area of the permanent magnet is reduced, the demagnetization rate of the secondary permanent magnet is reduced, and the anti-demagnetization capacity of the motor is improved.

[0035] In some embodiments, A and B also satisfy the following relationship: A / B<=0.4. If the included angle between the center lines of the main and secondary permanent magnets (the above ratio) is too large, the cost of the permanent magnet is increased, the cost of the motor is increased, and the performance-price ratio of the motor is reduced. By setting A / B<=0.4, the output torque of the motor can be effectively ensured, and the anti-demagnetization capacity of the motor is improved.

[0036] In some embodiments, the secondary permanent magnet 22 is a rectangular permanent magnet, and the projection of the secondary permanent magnet on the end face of the rotor core 1 is a rectangle. The main permanent magnet is also a rectangular permanent magnet, which can effectively reduce the contact area of the secondary permanent magnet and the main permanent magnet, thereby reducing the demagnetization magnetic field of the secondary permanent magnet on the main permanent magnet, reducing the demagnetization area of the main permanent magnet, improving the anti-demagnetization capacity of the main permanent magnet, without increasing the leakage magnetic field of the secondary permanent magnet, ensuring the efficiency of the motor, and at the same time, the processing technology of the rectangular permanent magnet is mature, the magnetic steel waste is reduced, the processing cost is reduced, and the cost of the motor is reduced.

[0037] In some embodiments, in the same tangential permanent magnet, the magnetization direction of the main permanent magnet 21 is along the circumferential direction of the rotor, the magnetization direction of the secondary permanent magnet 22 is along the circumferential direction of the rotor, and the included angle between the magnetization direction of the main permanent magnet and the magnetization direction of the secondary permanent magnet is C, C<=

[0038] 30°. The application can effectively increase the angle between the magnetization direction of the auxiliary permanent magnet and the armature magnetic field, reduce the demagnetization ability of the armature magnetic field on the permanent magnet, reduce the demagnetization rate of the magnetic flux density of the auxiliary permanent magnet, and improve the anti-demagnetization ability of the motor.

[0039] In some embodiments, the magnetization direction of the auxiliary permanent magnet 22 is perpendicular to the magnet center line of the auxiliary permanent magnet 22, and the magnetization direction of the main permanent magnet 21 is perpendicular to the magnet center line of the main permanent magnet 21. The magnetization direction of the auxiliary permanent magnet is perpendicular to the center line of the auxiliary permanent magnet, which on the one hand improves the anti-demagnetization ability of the auxiliary permanent magnet, and on the other hand reduces the difficulty of magnetic domain orientation and process difficulty of the magnetic steel. The magnetization direction of the main permanent magnet is perpendicular to the center line of the main permanent magnet, which improves the torque of the motor and improves the efficiency of the motor.

[0040] In some embodiments, between the two adjacent tangential permanent magnets constituting a magnetic pole, the auxiliary permanent magnet of one of the tangential permanent magnets is inclined relative to the main permanent magnet connected thereto in a first direction, and the auxiliary permanent magnet of the other tangential permanent magnet is inclined relative to the main permanent magnet connected thereto in a second direction, the first direction being opposite to the second direction; the inclination directions of the two auxiliary permanent magnets relative to the main permanent magnet are opposite, the minimum distance between the radially outer ends of the two adjacent auxiliary permanent magnets of one pole is E, the minimum distance between the radially outer ends of the two adjacent auxiliary permanent magnets of the adjacent pole is F, and the ratio E / F satisfies the following relationship: 1.4≥E / F≥0.8. Through the above setting, since the demagnetization rates of different permanent magnets are asymmetric, the inclination angle of the auxiliary permanent magnet is increased at the position prone to demagnetization, and the inclination angle of the auxiliary permanent magnet is reduced at the position not prone to demagnetization, thereby reducing the average demagnetization rate of the auxiliary permanent magnet, further improving the overall anti-demagnetization ability of the motor while ensuring the cost of the motor.

[0041] In some embodiments, the lengths of the two adjacent auxiliary permanent magnets in the radial direction of the rotor are not equal, one of which is G and the other of which is H, and the ratio G / H should satisfy the following relationship: 1.5≥G / H≥1. Through the above setting, the length of the auxiliary permanent magnet can be increased, the magnetic flux of the auxiliary permanent magnet can be improved, the torque of the motor can be improved, and the efficiency of the motor can be improved. Unequal length can ensure that the amount of permanent magnet used is not increased much while improving the efficiency of the motor, improving the performance-price ratio of the motor, and at the same time increasing the length of the auxiliary permanent magnet and reducing the demagnetization rate of the auxiliary permanent magnet.

[0042] In some embodiments, the coercive force of the auxiliary permanent magnet 22 is higher than the coercive force of the main permanent magnet 21, and the residual magnetism of the auxiliary permanent magnet is higher than the residual magnetism of the main permanent magnet.

[0043] In some embodiments, the material of the main permanent magnet is ferrite, and the material of the auxiliary permanent magnet is neodymium iron boron. Further preferably, the coercive force of the auxiliary permanent magnet is higher than that of the main permanent magnet, and the remanence of the auxiliary permanent magnet is higher than that of the main permanent magnet. For example, the material of the main permanent magnet is ferrite, and the material of the auxiliary permanent magnet is neodymium iron boron. Since the magnetic force of neodymium iron boron is stronger than that of ferrite, the main permanent magnet uses ferrite material with low magnetic performance, and the auxiliary permanent magnet, which is used as the permanent magnet for guiding the demagnetizing magnetic field, uses neodymium iron boron with high magnetic performance. The use of neodymium iron boron at different times improves the utilization rate of the permanent magnet, improves the efficiency, and reduces the cost of the motor.

[0044] The application further provides a permanent magnet motor, comprising the permanent magnet motor rotor according to any one of the preceding items, and further comprising a stator 4, wherein the stator 4 comprises a stator slot 41, the stator slot 41 has a slot opening 42, and the stator and the rotor have a gap 43 therebetween.

[0045] Those skilled in the art can easily understand that the advantageous technical features of the above-mentioned modes can be freely combined and superimposed without conflict.

[0046] The above only describes the preferred embodiments of the application and should not be used to limit the application. Any modification, equivalent replacement and improvement made within the spirit and principle of the application should be included in the protection scope of the application. The above only describes the preferred embodiments of the application and should not be used to limit the application. Any modification, equivalent replacement and improvement made within the spirit and principle of the application should be included in the protection scope of the application.

Claims

1. A permanent magnet synchronous motor rotor, characterized in that, include: The rotor core (1) and the tangential permanent magnet (2) are arranged on the rotor core and extend along the radial direction of the rotor core. There are N tangential permanent magnets, N≥2, and the N tangential permanent magnets (2) are arranged sequentially along the circumferential direction of the rotor core (1). The opposite sides of every two adjacent tangential permanent magnets (2) have the same polarity. The tangential permanent magnet (2) includes a main permanent magnet (21) and a secondary permanent magnet (22). The main permanent magnet (21) is located radially inside the secondary permanent magnet (22). The secondary permanent magnet (22) is inclined relative to the main permanent magnet (21). That is, the center line (24) of the secondary permanent magnet is not parallel to the center line (23) of the main permanent magnet and is not on the same straight line. There is an angle A between the center line (24) of the secondary permanent magnet and the center line (23) of the main permanent magnet. The angle between the center lines (23) of two adjacent main permanent magnets is set as B. A and B satisfy the following relationship: A / B≥0.

06.

2. The permanent magnet synchronous motor rotor according to claim 1, characterized in that: A and B also satisfy the following relationship: A / B≤0.

4.

3. The permanent magnet synchronous motor rotor according to claim 1, characterized in that: The secondary permanent magnet (22) is a rectangular permanent magnet, and its projection on the end face of the rotor core (1) is rectangular.

4. The permanent magnet synchronous motor rotor according to claim 1, characterized in that: In the same tangential permanent magnet, the magnetization direction of the main permanent magnet (21) is along the circumferential direction of the rotor, the magnetization direction of the auxiliary permanent magnet (22) is along the circumferential direction of the rotor, and the angle between the magnetization direction of the main permanent magnet and the magnetization direction of the auxiliary permanent magnet is C, where C≤30°.

5. The permanent magnet synchronous motor rotor according to claim 1, characterized in that: The magnetization direction of the secondary permanent magnet (22) is perpendicular to the magnet center line of the secondary permanent magnet (22), and the magnetization direction of the primary permanent magnet (21) is perpendicular to the magnet center line of the primary permanent magnet (21).

6. The permanent magnet synchronous motor rotor according to claim 1, characterized in that: Between two adjacent tangential permanent magnets constituting a magnetic pole, the secondary permanent magnet of one tangential permanent magnet is deflected in a first direction relative to the primary permanent magnet connected to it, and the secondary permanent magnet of the other permanent magnet is deflected in a second direction relative to the primary permanent magnet connected to it, the first direction being opposite to the second direction; the minimum distance between the radial outer ends of two adjacent secondary permanent magnets under one pole is E, and the minimum distance between the radial outer ends of two adjacent secondary permanent magnets under one pole is F, the ratio of E / F satisfies the following relationship: 1.4≥E / F≥0.

8.

7. The permanent magnet synchronous motor rotor according to any one of claims 1-6, characterized in that: The lengths of two adjacent secondary permanent magnets in the radial direction of the rotor are not equal. One of them has a length of G and the other has a length of H. The ratio of G / H should satisfy the following relationship: 1.5 ≥ G / H ≥ 1.

8. The permanent magnet synchronous motor rotor according to any one of claims 1-6, characterized in that: The coercivity of the secondary permanent magnet (22) is higher than that of the primary permanent magnet (21), and the remanence of the secondary permanent magnet is higher than that of the primary permanent magnet.

9. The permanent magnet synchronous motor rotor according to claim 8, characterized in that: The main permanent magnet is made of ferrite, and the secondary permanent magnet is made of neodymium iron boron.

10. A permanent magnet motor, characterized in that: The rotor of the permanent magnet synchronous motor includes any one of claims 1-9.

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