A permanent magnet motor rotor and a permanent magnet motor

Abstract

The application provides a permanent magnet motor rotor and a permanent magnet motor. The permanent magnet motor rotor comprises permanent magnets, the permanent magnets are at least two, the at least two permanent magnets constitute a pair of magnetic poles, there is a magnetic pole boundary between two adjacent permanent magnets, the two adjacent permanent magnets are connected at the magnetic pole boundary, the two adjacent permanent magnets are cut by a part of material at the magnetic pole boundary, a first cut part is formed, the first cut part comprises a part of material one cut by one of the permanent magnets at the magnetic pole boundary and a part of material two cut by the other permanent magnet at the magnetic pole boundary, a false magnetic steel is arranged at a vacancy after the part of material is cut, and the false magnetic steel is made of a non-magnetic material. According to the structure, the harmonic content of the motor can be obviously and effectively reduced by nearly 78%, the flat wave phenomenon of the back electromotive force waveform and the rectangularization phenomenon of the air gap magnetic density waveform can be simultaneously weakened.

Description

TECHNICAL FIELD

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

[0002] High-speed permanent magnet motor has the advantages of small size, high power density and high efficiency, so it has been focused on by electric field at home and abroad. Surface-mounted rotor is often used in high-speed motor field due to its simple structure and convenient assembly. The centrifugal force generated by high-speed permanent magnet motor rotor at high speed is very large, so a non-magnetic high-strength protective sleeve is usually added outside the permanent magnet because the tensile strength of the permanent magnet is low. Radial magnetization method is often used in magnetic ring and magnetic tile magnetization. This method can not only improve the utilization rate of permanent magnet, but also reduce the cost of permanent magnet, and is usually used in DC motor or brushless DC motor. However, radial magnetization of permanent magnet will result in small air gap magnetic flux density amplitude, rectangular wave shape and large harmonic content, and the sine property of back EMF waveform is poor. How to solve these problems is the key to improve the performance of the motor.

[0003] A surface-mounted permanent magnet motor with combined magnetization method is disclosed in Chinese patent CN108631468A. The rotor structure of the motor is surface-mounted, and the rotor magnetic poles are distributed on the outer surface of the rotor core. Each pole of the rotor magnetic pole includes a middle permanent magnet with strong magnetism and two side permanent magnets with weak magnetism. The two side permanent magnets are symmetrically distributed on both sides of the middle permanent magnet. The middle permanent magnet and the side permanent magnet use different permanent magnet materials and the same / different magnetization methods. Although this method can improve the fundamental wave amplitude of the radial air gap magnetic flux density and weaken the harmonics of the motor, the rotor scheme contains a large number of permanent magnet types. If it is applied to a surface-mounted rotor with a protective sleeve, there will be great difficulties in magnetization and assembly, especially for motors with a large number of poles.

[0004] Since the radial magnetization rotor in the prior art has the technical problems of generating large back EMF harmonic content and poor sine property of back EMF waveform, the present application designs a permanent magnet motor rotor and a permanent magnet motor. SUMMARY

[0005] Therefore, the technical problem to be solved by the present application is to overcome the defect that the radial magnetization rotor in the prior art generates large back EMF harmonic content, so as to provide a permanent magnet motor rotor and a permanent magnet motor.

[0006] In order to solve the above problems, the present application provides a permanent magnet motor rotor, which comprises:

[0007] Permanent magnets, the permanent magnets are at least two, at least two permanent magnets constitute a pair of magnetic poles, there is a magnetic pole interface between two adjacent permanent magnets, two adjacent permanent magnets are connected at the magnetic pole interface, two adjacent permanent magnets are cut off part of the material at the magnetic pole interface, forming a first cut-off part, the first cut-off part includes one of the permanent magnets cut off part of the material one at the magnetic pole interface, and the other permanent magnet cut off part of the material two at the magnetic pole interface, the vacancy after cutting off the part of the material is provided with a false magnetic steel, the false magnetic steel is made of non-magnetic material.

[0008] In some embodiments, at least two of the permanent magnets are spliced into a circular ring structure, and an axial hole is formed on the radial inner side, a mandrel is arranged in the axial hole, the first cut-off part is cut off in a direction perpendicular to the magnetic pole interface and along the axial direction of the mandrel, and in a radial cross section, the first cut-off part is an arc structure located at the radial outer end of the permanent magnet.

[0009] In some embodiments, the permanent magnets are two, forming a pair of magnetic poles, each permanent magnet is formed into a half ring structure, one end of the circumferential position of one of the permanent magnets is cut into a half arc structure by cutting in a direction perpendicular to the magnetic pole interface, the other end of the circumferential position is cut into a half arc structure by cutting in a direction perpendicular to the magnetic pole interface, one end of the circumferential position of the other permanent magnet is cut into a half arc structure by cutting in a direction perpendicular to the magnetic pole interface, the other end of the circumferential position is cut into a half arc structure by cutting in a direction perpendicular to the magnetic pole interface, and two half arc structures are spliced into an arc structure.

[0010] In some embodiments, the permanent magnets are four, forming two pairs of magnetic poles, each permanent magnet is formed into a 1 / 4 ring structure, one end of the circumferential position of the first permanent magnet is cut into a half arc structure by cutting in a direction perpendicular to the magnetic pole interface, the other end of the circumferential position is cut into a half arc structure by cutting in a direction perpendicular to the magnetic pole interface, one end of the circumferential position of the second permanent magnet is cut into a half arc structure by cutting in a direction perpendicular to the magnetic pole interface, the other end of the circumferential position is cut into a half arc structure by cutting in a direction perpendicular to the magnetic pole interface, one end of the circumferential position of the third permanent magnet is cut into a half arc structure by cutting in a direction perpendicular to the magnetic pole interface, the other end of the circumferential position is cut into a half arc structure by cutting in a direction perpendicular to the magnetic pole interface, one end of the circumferential position of the fourth permanent magnet is cut into a half arc structure by cutting in a direction perpendicular to the magnetic pole interface, the other end of the circumferential position is cut into a half arc structure by cutting in a direction perpendicular to the magnetic pole interface, and two half arc structures are spliced into an arc structure.

[0011] In some embodiments, the volume of the first cutaway portion in a single said permanent magnet is V1, the total volume of a single said permanent magnet before cutting is V, and V1 / V = 0.10-0.11.

[0012] In some embodiments, the permanent magnet further forms a second cutaway portion between the first cutaway portion and the shaft hole in a cutaway manner, and a pseudo-magnetic steel is arranged at the second cutaway portion.

[0013] In some embodiments, the second cutaway portion is cut by a cutting surface parallel to the magnetic pole interface, the cutting surface is spaced apart from the magnetic pole interface by a preset distance, and the second cutaway portion is a strip structure in a radial cross section after cutting.

[0014] In two adjacent permanent magnets, one of the permanent magnets has a first cutting surface parallel to and spaced apart from the magnetic pole interface, and the other permanent magnet has a second cutting surface parallel to and spaced apart from the magnetic pole interface, a portion between the first cutting surface and the magnetic pole interface is cut away, and a portion between the second cutting surface and the magnetic pole interface is cut away, and the first cutting surface and the second cutting surface together form the strip structure.

[0015] In some embodiments, one of the second cutaway portions is arranged at one circumferential end of the permanent magnet, and the other second cutaway portion is arranged at the other circumferential end of the permanent magnet.

[0016] In some embodiments, the volume of the second cutaway portion in a single said permanent magnet is Va, the volume of a single said permanent magnet before cutting is V, the total cutaway volume of a single said permanent magnet is V2, the volume of the first cutaway portion is V1, V2 = V1 + Va, and V1 / V = 0.10-0.11, V2 / V = 0.13-0.14.

[0017] In some embodiments, a third cutaway portion is formed in a cutaway manner at the radially outermost end of the magnetic pole center line of the permanent magnet, and the third cutaway portion is filled with a pseudo-magnetic steel.

[0018] In some embodiments, the third cutaway portion is an arc-shaped portion formed by cutting with a plane perpendicular to the magnetic pole center line.

[0019] In some embodiments, the volume of the third cutaway portion in a single said permanent magnet is Vb, the volume of a single said permanent magnet before cutting is V, the total cutaway volume of a single said permanent magnet is V3, the volume of the first cutaway portion of a single said permanent magnet is V1, the volume of the second cutaway portion of a single said permanent magnet is Va, V2 = V1 + Va, V3 = V1 + Va + Vb, and V1 / V = 0.10-0.11, V2 / V = 0.13-0.14, V3 / V = 0.14-0.15.

[0020] In some embodiments, the first cutout portion is cut in a radial direction and along the axis of the mandrel, and in a radial cross-section, the first cutout portion is a fan ring structure on the permanent magnet.

[0021] In some embodiments, the volume of the single permanent magnet before cutting is V, the total cutout volume of the single magnetic pole is V4, and V4 / V = 0.20-0.25.

[0022] The application also provides a permanent magnet motor comprising the permanent magnet motor rotor.

[0023] The permanent magnet motor rotor and the permanent magnet motor provided by the application have the following beneficial effects:

[0024] The first cutout portion is formed by cutting at the pole boundary surface of the permanent magnet, and a portion of material is symmetrically and parallelly removed on both sides of the permanent magnet with the center line of the permanent magnet pole as a reference. For a multi-pole motor, a portion of material is cut at the boundary of any two poles perpendicular to the pole boundary surface, the cutout portion is replaced by a pseudo-magnetic steel, and finally a protective sleeve is sleeved outside the permanent magnet to form a rotor. Through the structure, the harmonic content of the motor can be effectively reduced by nearly 78%, the flat-top wave phenomenon of the back EMF waveform and the rectangularization phenomenon of the air gap flux waveform are simultaneously weakened. That is, a new type of radial magnetization surface-mounted rotor is provided, which effectively reduces the back EMF harmonic content of the surface-mounted radial magnetization rotor without increasing the amount of permanent magnets, and increases the sinusoidal nature of the back EMF waveform. The application can greatly reduce the back EMF harmonic content, increase the sinusoidal nature of the back EMF waveform, improve the sinusoidal nature of the air gap flux waveform, optimize the electromagnetic performance, and make the permanent magnet motor run more smoothly and reliably. The rotor structure and assembly process of the application are simple, which effectively reduces the manufacturing cost and manufacturing process difficulty. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a cross-sectional structure diagram of the permanent magnet motor rotor of embodiment 1 of the application;

[0026] Figure 2a is a structure diagram of a pair of pole permanent magnet of Figure 1 ;

[0027] Figure 2b is a structure diagram of a multi-pole permanent magnet of Figure 1 ;

[0028] Figure 3a is a back EMF waveform diagram of an existing ordinary radial magnetization;

[0029] Figure 3b is a radial magnetization back EMF waveform diagram of embodiment 1 of the application;

[0030] Figure 4a is a structural diagram of a single permanent magnet of alternative embodiment 1 of the present application;

[0031] Figure 4b is a structural diagram of a pair of pole permanent magnets of alternative embodiment 1;

[0032] Figure 5 is a back EMF waveform diagram of alternative embodiment 1 of the present application with radial magnetization;

[0033] Figure 6a is a structural diagram of a single permanent magnet of alternative embodiment 2 of the present application;

[0034] Figure 6b is a structural diagram of a pair of pole permanent magnets of alternative embodiment 2;

[0035] Figure 7 is a back EMF waveform diagram of alternative embodiment 2 of the present application with radial magnetization;

[0036] Figure 8a is a structural diagram of a single permanent magnet of alternative embodiment 3 of the present application;

[0037] Figure 8b is a structural diagram of a pair of pole permanent magnets of alternative embodiment 3;

[0038] Figure 9 is a back EMF waveform diagram of alternative embodiment 3 of the present application with radial magnetization.

[0039] Reference signs are indicated as:

[0040] 1, permanent magnet; 10, magnetic pole boundary surface; 11, magnetic pole center line; 2, dummy magnetic steel; 3, mandrel; 4, first cutout portion; 5, second cutout portion; 6, third cutout portion. DETAILED DESCRIPTION

[0041] In the description of the present application, it should be noted that the terms "inner", "outer" and the like indicate the positional or locational relationship based on the positional or locational relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0042] In the description of the present application, it is necessary to point out that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "contact", "communication" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] The present application also provides a permanent magnet motor rotor, comprising:

[0044] Permanent magnets 1, the permanent magnets 1 are at least two, at least two permanent magnets constitute a pair of magnetic poles, there is a magnetic pole interface 10 between two adjacent permanent magnets 1, two adjacent permanent magnets 1 meet at the magnetic pole interface 10, two adjacent permanent magnets 1 are cut off part of the material at the magnetic pole interface 10 (preferably in the form of cutting), forming a first cut-off part 4, the first cut-off part 4 includes one of the permanent magnets 1 cut off part of the material one at the magnetic pole interface 10, and the other permanent magnet 1 cut off part of the material two at the magnetic pole interface 10, the vacancy after cutting off the part of the material is provided with a false magnetic steel 2, the false magnetic steel 2 is made of non-magnetic material.

[0045] The present application forms a first cut-off part by cutting off at the magnetic pole interface of the permanent magnet, removes a part of the material symmetrically and parallelly on both sides of the permanent magnet with the permanent magnet magnetic pole center line as reference. For multiple-pole motor, a part of the material is cut off at the interface of any two magnetic poles perpendicular to the magnetic pole interface. The cut-off part is replaced by false magnetic steel. Finally, a protective sleeve is sleeved outside the permanent magnet to form a rotor. Through the structure, the harmonic content of the motor can be reduced by nearly 78%, the flat-top wave phenomenon of the back electromotive force waveform and the rectangularization phenomenon of the air gap flux waveform can be reduced synchronously. That is, a new type of radial magnetization surface-mounted rotor is provided. The back electromotive force harmonic content of the surface-mounted radial magnetization rotor is effectively reduced without additional increase of the amount of permanent magnet, and the sine property of the back electromotive force waveform is increased. The present application can greatly reduce the back electromotive force harmonic content, increase the sine property of the back electromotive force waveform, improve the sine property of the air gap flux waveform, optimize the electromagnetic performance, and make the permanent magnet motor run more smoothly and reliably. The rotor structure and assembly process of the present application are simple, which effectively reduces the manufacturing cost and manufacturing process difficulty.

[0046] In some embodiments, at least two of the permanent magnets 1 are spliced into a circular ring structure, and an axial hole is formed on the inner side in the radial direction, a mandrel 3 is arranged in the axial hole, the first cutout portion 4 is cut out in a direction perpendicular to the magnetic pole boundary surface 10 and along the axial direction of the mandrel 3, and in the radial cross section, the first cutout portion 4 is an arc structure located at the radial outer end of the permanent magnet 1. This is the preferred structure of Embodiment 1, Alternative Embodiment 1 and Alternative Embodiment 2 of the present application, that is, the first cutout portion is an arc structure cut out at the magnetic pole boundary surface in a direction perpendicular to the magnetic pole boundary surface, which can reduce the harmonic content of the back EMF and also increase the sinusoidal nature of the back EMF waveform, as shown in Figures 3a-3b

[0047] The present application takes the center line of the magnetic pole of the permanent magnet as a reference, and a part of material is symmetrically and parallelly removed on both sides of the permanent magnet (for a multi-pole motor, a part of material is cut out at any two magnetic pole boundaries in a direction perpendicular to the magnetic pole boundary surface), the cutout portion is replaced by a pseudo-magnetic steel, and finally a protective sleeve is sleeved outside the permanent magnet to form a rotor. Through the structure, the harmonic content of the motor can be significantly and effectively reduced by nearly 78%, and the flat-top wave phenomenon of the back EMF waveform and the rectangularization phenomenon of the air gap flux waveform are simultaneously weakened.

[0048] The technical problems solved are as follows:

[0049] The radial magnetization rotor of the present application can effectively reduce the harmonic content of the back EMF of the surface-mounted radial magnetization rotor without increasing the amount of permanent magnets, and increase the sinusoidal nature of the back EMF waveform.

[0050] The beneficial effects are as follows:

[0051] 1. The harmonic content of the back EMF can be greatly reduced, and the sinusoidal nature of the back EMF waveform can be increased, the sinusoidal nature of the air gap flux waveform is improved, the electromagnetic performance is optimized, and the permanent magnet motor operates more stably and reliably;

[0052] 2. The rotor structure and assembly process are simple, which effectively reduces the manufacturing cost and manufacturing process difficulty.

[0053] Figure 1 It is a schematic diagram of the radial magnetization permanent rotor structure. The direction of the magnetic force line represents the magnetization direction of the magnetic steel. The magnetization direction of one magnetic pole is from the center of the circle to the outside, and the magnetization direction of the other magnetic pole is from the outside to the center of the circle. Permanent magnet 1, pseudo-magnetic steel 2, mandrel 3.

[0054] Figures 2a-2b It is a schematic diagram of a single magnetic pole permanent magnet shape. Among them Figure 2a It is a schematic diagram of a pair of pole permanent magnet structure, Figure 2b It is a schematic diagram of a multi-pole permanent magnet structure. ​

[0055] Figures 3a-3b The motor back EMF waveform is shown in the figure. Wherein Figure 3a The motor back EMF waveform of a common radial magnetization rotor is shown in the figure. The waveform is flat and the sine property is poor. Figure 3b The motor back EMF waveform of the present application is shown in the figure. The sine property is good.

[0056] As Figure 2a In some embodiments, the permanent magnet 1 is two, forming a pair of magnetic poles, each permanent magnet 1 is formed into a half-annular structure, and at the position of one end of the circumference of one of the permanent magnets, a half-arch structure is formed by cutting in a direction perpendicular to the magnetic pole interface 10, and at the position of the other end of the circumference, a half-arch structure is formed by cutting in a direction perpendicular to the magnetic pole interface 10, and at the position of one end of the circumference of the other permanent magnet, a half-arch structure is formed by cutting in a direction perpendicular to the magnetic pole interface 10, and at the position of the other end of the circumference, a half-arch structure is formed by cutting in a direction perpendicular to the magnetic pole interface 10, and the two half-arch structures are spliced to form an arch structure. Figure 2a As shown, this is the preferred structure of embodiment 1 of the present application, that is, the half-annular structure of a single permanent magnet, and first cutaway parts are provided at the magnetic pole interfaces on both sides, which can effectively reduce the back EMF harmonic content and effectively increase the sine property of the back EMF waveform.

[0057] As Figure 2b In some embodiments, the permanent magnet 1 is four, forming two pairs of magnetic poles, each permanent magnet 1 is formed into a 1 / 4 annular structure, and at the position of one end of the circumference of the first permanent magnet, a half-arch structure is formed by cutting in a direction perpendicular to the magnetic pole interface 10, and at the position of the other end of the circumference, a half-arch structure is formed by cutting in a direction perpendicular to the magnetic pole interface 10, and at the position of one end of the circumference of the second permanent magnet, a half-arch structure is formed by cutting in a direction perpendicular to the magnetic pole interface 10, and at the position of the other end of the circumference, a half-arch structure is formed by cutting in a direction perpendicular to the magnetic pole interface 10, and at the position of one end of the circumference of the third permanent magnet, a half-arch structure is formed by cutting in a direction perpendicular to the magnetic pole interface 10, and at the position of the other end of the circumference, a half-arch structure is formed by cutting in a direction perpendicular to the magnetic pole interface 10, and at the position of one end of the circumference of the fourth permanent magnet, a half-arch structure is formed by cutting in a direction perpendicular to the magnetic pole interface 10, and at the position of the other end of the circumference, a half-arch structure is formed by cutting in a direction perpendicular to the magnetic pole interface 10, and the two half-arch structures are spliced to form an arch structure.

[0058] As Figure 2b This is the preferred structure of embodiment 1 of the present application, that is, the 1 / 4 annular structure of a single permanent magnet, which is a two-pole permanent magnet structure.

[0059] The best embodiment of the present application is as follows: taking the center line of the magnetic pole of the permanent magnet as a reference, a part of material is removed symmetrically and parallelly on both sides of the permanent magnet (for a multi-pole motor, a part of material is removed perpendicularly at the interface of the magnetic pole), the removed part is replaced by a false magnetic steel, the permanent magnet and the false magnetic steel are bonded by adhesive material to form a required circular profile, and then a high-strength protective sleeve is sleeved outside to form a rotor, so as to meet the requirements of the permanent magnet motor in high-speed operation.

[0060] In order to ensure the strength of the permanent magnet and the reliability of the rotor operation, the removed part is filled by bonding the false magnetic steel. For a ring-shaped or tile-shaped permanent magnet rotor, the central part can be filled with a core shaft made of magnetic conductive material to increase the magnetic conductivity and improve the electromagnetic performance of the motor.

[0061] The false magnetic steel can be a material with non-magnetic, high strength and similar density to the permanent magnet, such as alloy, stainless steel, etc.

[0062] In some embodiments, the volume of the first removed part 4 in a single permanent magnet is V1, the total volume of a single permanent magnet before being removed is V, and V1 / V = 0.10-0.11. The volume of the single magnetic pole permanent magnet before being cut according to the present application is V, and the optimal volume after being cut parallelly is V1, and V1 / V = 0.10-0.11.

[0063] Without using the scheme of the present application, the harmonic content of the rotor with radial magnetization is A, and after using the scheme of the present application, the harmonic content of the motor is B, and (A-B) / A≈0.78, that is, the harmonic content of the motor can be reduced by about 78%.

[0064] The rotor permanent magnet structure according to the present application is relatively simple, and is convenient for processing and assembly. It can be used for a pre-magnetized rotor with a protective sleeve, a post-magnetized rotor, and is also suitable for a single-pole or multi-pole motor.

[0065] Alternative embodiment 1 is as follows: Figures 4a-5 In some embodiments, the permanent magnet 1 also forms a second removed part 5 between the first removed part 4 and the shaft hole in a removed manner, and a false magnetic steel is also arranged at the second removed part 5.

[0066] Alternative embodiment 1 of the present application cuts an equal amount of permanent magnet material with a volume of V1 parallelly on both sides of the permanent magnet along the direction of the center line of the two magnetic poles, and cuts a volume of Va of material at the magnetic pole interface (perpendicular to the direction of the center line of the magnetic pole), the removed part is filled by bonding the false magnetic steel, and the materials are bonded by adhesive material to form a required cylindrical profile, and then a high-strength protective sleeve is sleeved outside to form a rotor.

[0067] In some embodiments, the second cutaway part 5 is cutaway by a plane parallel to the pole interface 10, the plane is spaced apart from the pole interface 10 by a preset distance, and the second cutaway part 5 is a strip structure in the radial cross section after cutting;

[0068] In the adjacent two permanent magnets 1, one of the permanent magnets 1 has a first plane parallel to and spaced apart from the pole interface 10, and the other permanent magnet 1 has a second plane parallel to and spaced apart from the pole interface 10, the part between the first plane and the pole interface is cutaway, and the part between the second plane and the pole interface is cutaway, and the first plane and the second plane together form the strip structure.

[0069] FIG. 4 is a schematic diagram of an alternative embodiment of the present application, the permanent magnet 1, the pseudo-magnetic steel 2, the first cutaway part 4 and the second cutaway part 5 are parts of the present application where material is removed, the sum of the volumes of the first cutaway part 4 is V1, and the sum of the volumes of the second cutaway part 5 is Va.

[0070] Figure 5 The counter electromotive force waveform of the present alternative embodiment.

[0071] In some embodiments, one second cutaway part 5 is arranged at one circumferential end of the permanent magnet 1, and one second cutaway part 5 is arranged at the other circumferential end of the permanent magnet 1.

[0072] In some embodiments, the volume of the second cutaway part 5 in a single permanent magnet is Va, the volume of the single permanent magnet before cutting is V, the total cutaway volume of the single permanent magnet 1 is V2, the volume of the first cutaway part 4 in a single permanent magnet is V1, V2=V1+Va, and V1 / V=0.10-0.11, V2 / V=0.13-0.14.

[0073] The volume of the single magnetic pole permanent magnet of the present application before cutting is V, the optimal total cutaway volume of the single magnetic pole permanent magnet is V2, V2=V1+Va, where V1 / V=0.10-0.11, V2 / V=0.13-0.14.

[0074] The harmonic content of the radial magnetized rotor without using the scheme of the present application is A, and the harmonic content of the motor after using the scheme of the present application is B, (A-B) / A≈0.79, that is, the harmonic content of the motor can be reduced by about 79%, and the harmonic reduction effect is ideal.

[0075] Alternative embodiment 2, as Figures 6a-7 In some embodiments, a third cutaway part 6 is formed by cutting at the radially outermost end of the pole center line 11 of the permanent magnet 1, and the third cutaway part 6 is filled with a pseudo-magnetic steel.

[0076] The alternative embodiment 2 of the present application cuts the permanent magnet material of V1 volume on both sides of the permanent magnet along the direction of the center line of the two magnetic poles, cuts the material of Va volume at the magnetic pole interface (perpendicular to the direction of the pole center line), cuts the material of Vb volume at the top of the pole center in parallel, the cut parts are filled with false magnetic steel, and the materials are bonded to form a required cylindrical profile, and then a high-strength protective sleeve is provided outside to form a rotor.

[0077] In some embodiments, the third cut-out part 6 is an arc-shaped part formed by cutting along a plane perpendicular to the pole center line 11.

[0078] Figures 6a-6b The alternative embodiment 2 is shown in the schematic diagram, the permanent magnet 1, the false magnetic steel 2, the first cut-out part 4, the second cut-out part 5, and the third cut-out part 6 are material removal parts of the present application, the sum of the volumes of the first cut-out part 4 is V1, the sum of the volumes of the second cut-out part 5 is Va, and the volume of the third cut-out part 6 is Vb.

[0079] Figure 7 The counter-electromotive force waveform diagram of the alternative embodiment is shown.

[0080] In some embodiments, the volume of the third cut-out part 6 in a single permanent magnet is Vb, the volume of the single permanent magnet before cutting is V, the total cut-out volume of the single permanent magnet is V3, the volume of the first cut-out part 4 of the single permanent magnet is V1, the volume of the second cut-out part 5 of the single permanent magnet is Va, V2 = V1 + Va, V3 = V1 + Va + Vb, and V1 / V = 0.10-0.11, V2 / V = 0.13-0.14, and V3 / V = 0.14-0.15.

[0081] The volume of the single magnetic pole permanent magnet before cutting of the alternative embodiment 2 of the present application is V, the optimal total cut-out volume of the single magnetic pole permanent magnet is V3, V3 = V2 + Vb, V2 = V1 + Va, V1 / V = 0.10-0.11, V2 / V = 0.13-0.14, and V3 / V = 0.14-0.15.

[0082] When the present application is not used, the harmonic content of the rotor with radial magnetization is A, and after the present application is used, the harmonic content of the motor is B, (A-B) / A≈0.73, that is, the harmonic content of the motor can be reduced by about 73%, and the harmonic reduction effect is ideal.

[0083] Alternative embodiment 3, as Figures 8a-9 In some embodiments, the first cut-out part 4 is cut along the radial direction and along the axis direction of the core shaft 3, and in the radial cross section, the first cut-out part 4 is a fan ring structure on the permanent magnet 1.

[0084] The alternative embodiment 3 cuts a volume of material in a fan angle on both sides of the pole interface, the optimal cut volume is V4, the cut part is filled with false magnetic steel, and the materials are bonded with adhesive material to form a required cylindrical profile, and then a high-strength protective sleeve is provided outside to form a rotor.

[0085] Figures 8a-8b The alternative embodiment is shown in the figure, permanent magnet 1, false magnetic steel 2, and first cut part 4 are the material removal parts of the present application, and the sum of the volumes of the first cut part 4 is V4.

[0086] Figure 9 The counter-electromotive force waveform diagram of the alternative embodiment is shown in the figure.

[0087] In some embodiments, the volume of a single permanent magnet before cutting is V, the total cut volume of a single magnetic pole is V4, and V4 / V=0.20-0.25.

[0088] The volume of a single permanent magnet before cutting is V, the optimal total cut volume of a single magnetic pole is V4, and V4 / V=0.20-0.25.

[0089] The harmonic content of a rotor with radial magnetization without using the present application is A, and the harmonic content of the motor after using the present application is B, (A-B) / A≈0.56, that is, the harmonic content of the motor can be reduced by about 56%, and the harmonic reduction effect is relatively ideal.

[0090] The present application also provides a permanent magnet motor, which comprises the above-mentioned permanent magnet motor rotor.

[0091] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications shall be considered as the protection scope of the present application.

Claims

1. A permanent magnet electric machine rotor, characterized by: include: Permanent magnets (1), wherein there are at least two permanent magnets (1), and the at least two permanent magnets form a pair of magnetic poles, a magnetic pole interface (10) exists between two adjacent permanent magnets (1), the two adjacent permanent magnets (1) are connected at the magnetic pole interface (10), and a portion of material of the two adjacent permanent magnets (1) is cut off at the magnetic pole interface (10) to form a first cut-off portion (4), the first cut-off portion (4) includes a portion of material 1 of one permanent magnet (1) cut off at the magnetic pole interface (10), and a portion of material 2 of the other permanent magnet (1) cut off at the magnetic pole interface (10), and a dummy magnetic steel (2) is provided in the vacant portion after the portion of material is cut off, and the dummy magnetic steel (2) is made of a non-magnetic material; At least two of the permanent magnets (1) are spliced ​​into a circular ring structure and form an axial hole located radially inward, a core shaft (3) is arranged in the axial hole, the first cut-off portion (4) is formed by cutting in a direction perpendicular to the magnetic pole boundary surface (10) and along the axial direction of the core shaft (3), and in a radial cross section, the first cut-off portion (4) is an arched structure located at the radial outer end of the permanent magnet (1); the volume of the first cut-off portion (4) in a single permanent magnet is V1, the total volume of the single permanent magnet before cutting is V, and V1 / V=0.10~0.

11.

2. The permanent magnet motor rotor according to claim 1, characterized in that: There are two permanent magnets (1) forming a pair of magnetic poles, and each permanent magnet (1) is formed into a semi-annular structure, wherein one circumferential end of one permanent magnet is cut in a direction perpendicular to the magnetic pole boundary surface (10) to form a half-bow structure, and the other circumferential end is cut in a direction perpendicular to the magnetic pole boundary surface (10) to form a half-bow structure, and the other circumferential end of the other permanent magnet is cut in a direction perpendicular to the magnetic pole boundary surface (10) to form a half-bow structure, and the other circumferential end is cut in a direction perpendicular to the magnetic pole boundary surface (10) to form a half-bow structure, and the two half-bow structures are spliced ​​to form a bow structure.

3. The permanent magnet motor rotor according to claim 1, characterized in that: The permanent magnets (1) are four, forming two pairs of magnetic poles, each permanent magnet (1) is formed as a 1 / 4 annular structure, wherein the circumferential one end of the first permanent magnet is cut into a half-arch structure by a direction perpendicular to the magnetic pole interface (10), the circumferential other end is cut into a half-arch structure by a direction perpendicular to the magnetic pole interface (10), the circumferential one end of the second permanent magnet is cut into a half-arch structure by a direction perpendicular to the magnetic pole interface (10), the circumferential other end is cut into a half-arch structure by a direction perpendicular to the magnetic pole interface (10), the circumferential one end of the third permanent magnet is cut into a half-arch structure by a direction perpendicular to the magnetic pole interface (10), the circumferential other end is cut into a half-arch structure by a direction perpendicular to the magnetic pole interface (10), the circumferential one end of the fourth permanent magnet is cut into a half-arch structure by a direction perpendicular to the magnetic pole interface (10), the circumferential other end is cut into a half-arch structure by a direction perpendicular to the magnetic pole interface (10), and two half-arch structures are spliced into an arch structure.

4. The permanent magnet motor rotor according to any one of claims 1-3, characterized in that: The permanent magnet (1) further forms a second cutaway portion (5) between the first cutaway portion (4) and the shaft hole in a cutaway manner, and a false magnetic steel is also arranged at the second cutaway portion (5).

5. The permanent magnet motor rotor according to claim 4, characterized in that: The second cutaway portion (5) is cut away by a cutting surface parallel to the magnetic pole interface (10), the cutting surface is spaced apart from the magnetic pole interface (10) by a preset distance, and the second cutaway portion (5) is a strip structure in the radial cross section after cutting; In the two adjacent permanent magnets (1), one of the permanent magnets (1) has a first cutting surface parallel to and spaced apart from the magnetic pole interface (10), and the other permanent magnet (1) has a second cutting surface parallel to and spaced apart from the magnetic pole interface (10), the portion between the first cutting surface and the magnetic pole interface is cut away, the portion between the second cutting surface and the magnetic pole interface is cut away, and the first cutting surface and the second cutting surface together form the strip structure.

6. The permanent magnet motor rotor according to claim 4, characterized in that: One second cutaway portion (5) is arranged at the circumferential one end of the permanent magnet (1), and one second cutaway portion (5) is arranged at the circumferential other end.

7. The permanent magnet motor rotor according to claim 4, characterized in that: The volume of the second cutaway portion (5) in a single permanent magnet is Va, the volume of a single permanent magnet before cutting is V, the total cutaway volume of a single permanent magnet (1) is V2, the volume of the first cutaway portion (4) in a single permanent magnet is V1, V2=V1+Va, and V1 / V=0.10~0.11, V2 / V=0.13~0.

14.

8. The permanent magnet motor rotor according to claim 4, characterized in that: A third cutaway portion (6) is formed in a cutaway manner at the radially outermost end of the pole center line (11) of the permanent magnet (1), and the third cutaway portion (6) is filled with a pseudo-magnetic steel.

9. The permanent magnet motor rotor according to claim 8, characterized in that: The third cutaway portion (6) is an arcuate portion formed by cutting away with a plane perpendicular to the pole center line (11).

10. The permanent magnet motor rotor according to claim 8, characterized in that: The volume of the third cutaway portion (6) in a single permanent magnet is Vb, the volume of a single permanent magnet before cutting is V, the total cutaway volume of a single permanent magnet is V3, the volume of the first cutaway portion (4) of a single permanent magnet is V1, the volume of the second cutaway portion (5) of a single permanent magnet is Va, V2=V1+Va, V3=V1+Va+Vb, and V1 / V=0.10~0.11, V2 / V=0.13~0.14, V3 / V=0.14~0.

15.

11. The permanent magnet motor rotor according to claim 1, characterized in that: At least two permanent magnets (1) are spliced into a circular ring structure and form an axially inner shaft hole, a mandrel (3) is arranged in the shaft hole, the first cutaway portion (4) is cut away in the radial direction and along the axial direction of the mandrel (3), and in the radial cross section, the first cutaway portion (4) is a fan ring structure on the permanent magnet (1).

12. The permanent magnet motor rotor according to claim 11, characterized in that: The volume of a single permanent magnet before cutting is V, and the total cutaway volume of a single magnetic pole is V4, V4 / V=0.20~0.

25.

13. A permanent magnet electric machine characterized by: A permanent magnet motor rotor according to any one of claims 1-12.

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