Rotor punching sheet and permanent magnet motor thereof

Abstract

The invention discloses a rotor punching sheet and a permanent magnet motor thereof, the rotor punching sheet comprises a sheet body and even number of synthetic magnetic poles, and the even number of synthetic magnetic poles are distributed on the sheet body along the circumferential direction; an arc corresponding to the outline of the outer circle of each combined magnetic pole and the shaft hole of the sheet body are eccentric, and a first notch and a second notch which are concave inwards are formed in the two ends of the arc respectively and are symmetrical about the midpoint of the arc. The arcs of the outer circle outlines of the combined magnetic poles are eccentric to the rotor shaft hole, and each arc is provided with the first notches and the second notches which are symmetrically distributed, so that uneven air gap distribution which is in a specific shape and is in a certain regular size is formed, which is equivalent to that very ingenious pole cutting treatment is performed on the rotor; the sine degree of air gap flux density can be optimized, the effects of weakening harmonic waves of all orders and reducing cogging torque are achieved, and vibration and electromagnetic noise are reduced while the efficiency of the motor is improved.

Description

Technical Field

[0001] The invention relates to the technical field of permanent magnet motors, and in particular to a rotor punching sheet and a permanent magnet motor thereof. Background Art

[0002] The continuous progress of battery technology, drive technology, and intelligent technology has brought new development opportunities to the electric motorcycle and electric four-wheel vehicle industry, and the current market is showing a very strong growth momentum. At the same time, new technologies and processes make lightweight design and high performance possible, and high-performance motors and drive systems can provide faster acceleration and a more stable driving experience.

[0003] Electric motorcycles and electric vehicles have become excellent choices for consumers for short-distance travel due to their environmental protection, low carbon and convenient features, and have also shown broad application prospects in areas such as shared travel. In order to save costs and facilitate design and manufacturing, electric motorcycles and electric four-wheeled vehicles currently use 12-slot 10-pole concentrated winding motors with built-in "straight" or "V-shaped" magnetic pole magnet steel distribution. The motors produced have the advantages of small cogging torque and low manufacturing cost. However, its disadvantages are also very obvious. Among them, the risk of demagnetization during high-speed weak magnetic field and the high-intensity vibration noise excited by electromagnetic force waves are technical problems that need to be solved urgently. Summary of the invention

[0004] The embodiment of the present invention provides a rotor punching sheet and a permanent magnet motor thereof, which solve the technical problem of vibration noise existing in a traditional permanent magnet motor.

[0005] In order to solve the above problems, according to one aspect of the present application, an embodiment of the present invention provides a rotor punching, which includes a sheet body and a synthetic magnetic pole. The synthetic magnetic poles have an even number, and the even number of synthetic magnetic poles are distributed circumferentially on the sheet body; the arc corresponding to the outer circular contour of each synthetic magnetic pole is eccentric to the axial hole of the sheet body, and the two ends of the arc respectively have a first notch and a second notch that are recessed inward, and the first notch and the second notch are symmetrical about the midpoint of the arc.

[0006] In some embodiments, the composite magnetic pole includes a first magnet slot, a second magnet slot and a third magnet slot, the first magnet slot and the second magnet slot are arranged obliquely in different directions, there is a first distance between the first ends of the first magnet slot and the second magnet slot, there is a second distance between the second ends of the first magnet slot and the second magnet slot, the first distance is greater than the second distance, and the first ends of the first magnet slot and the second magnet slot are facing the edge of the sheet, and the third magnet slot is arranged between the first ends of the first magnet slot and the second magnet slot.

[0007] In some embodiments, the composite magnetic pole further includes a first permanent magnet, a second permanent magnet and a third permanent magnet, the first permanent magnet is arranged in the first magnet slot, the second permanent magnet is arranged in the second magnet slot, and the third permanent magnet is arranged in the third magnet slot; the first magnet slot, the second magnet slot and the third magnet slot all have a limiting boss;

[0008] And / or the width a1 of the third magnet slot and the width a2 of the first magnet slot and the second magnet slot satisfy: a1=k a ×a2,k a =0.5~1.

[0009] In some embodiments, a first magnetic isolation bridge is formed between the first magnetic slot and the edge of the sheet, and between the second magnetic slot and the edge of the sheet, and the distance between the side of the first magnetic slot close to the edge of the sheet and the edge of the sheet is 0.5mm-1.5mm; a second magnetic isolation bridge is formed between the third magnetic slot and the edge of the sheet, and the distance between the side of the second magnetic slot close to the edge of the sheet and the edge of the sheet is 0.5mm-1.5mm; a third magnetic isolation bridge is formed between the first magnetic slot and the end of the second magnetic slot away from the edge of the sheet, and the distance between the end of the first magnetic slot away from the edge of the sheet and the end of the second magnetic slot away from the edge of the sheet is 0.5mm-3mm; and / or the upper end of the third magnetic isolation bridge is at a right angle.

[0010] In some embodiments, the bottom of both sides of the first magnet groove respectively have a first semicircular groove and a second semicircular groove, wherein the first semicircular groove is close to the edge of the sheet; the bottom of both sides of the second magnet groove respectively have a third semicircular groove and a fourth semicircular groove, wherein the third semicircular groove is close to the edge of the sheet; the bottom of both sides of the third magnet groove respectively have a fifth semicircular groove and a sixth semicircular groove; the radius of the fifth semicircular groove and the sixth semicircular groove is 0.15mm-1mm, the radius of the first semicircular groove and the third semicircular groove is 0.2mm-1.5mm, and the radius of the second semicircular groove and the fourth semicircular groove is 0.15mm-1mm.

[0011] In some embodiments, the upper side of the third magnet slot has a symmetrically distributed first oblique side gap and a second oblique side gap, and the distance x1 between the ends of the first oblique side gap and the second oblique side gap close to each other satisfies: x1=k x ×b1, where k x =0.5-0.9, b1 is the distance between the fifth semicircular groove and the sixth semicircular groove, and the angle j1 between the first oblique side gap and the second oblique side gap and the horizontal plane satisfies: j1=0.3-30°;

[0012] The upper end of the first magnet slot away from the sheet body has a third oblique side gap, and the length x2 of the projection of the third oblique side gap on the reference plane satisfies: x2=k x '×b2, where k x '=0.1~0.3, b2 is the distance between the first semicircular groove and the second semicircular groove, and b1 and b2 satisfy: b1=k b ×b2,k b =0.5~1; the angle j2 between the third oblique side gap and the reference plane satisfies: j2=0.3~30°, wherein the reference plane is the inclined surface of the second permanent magnet;

[0013] The upper end of the second magnet slot away from the sheet body has a fourth oblique side gap, and the fourth oblique side gap has the same length and inclination angle as the third oblique side gap.

[0014] In some embodiments, the eccentricity d between the arc corresponding to the outer contour of each synthetic magnetic pole and the axial hole of the sheet body satisfies: d=k d ×r0, where k d =0.15~0.55; the radius r1 of the arc corresponding to the outer contour of the synthetic magnetic pole and the diameter r0 of the sheet body satisfy: r1=k r ×r0,k r =0.5~0.9.

[0015] In some embodiments, the first notch and the second notch are uniform arcs, and the corresponding radius r2 satisfies: r2=k r '×r1,k r '=0.02~0.4; and the first notch and the second notch are connected to the outer circular contour of the synthetic magnetic pole through a transition arc.

[0016] In some embodiments, the sheet body has rivet holes, ventilation holes, sheet sorting slots and screw through holes. There are at least two rivet holes and screw through holes, and the two are cross-arranged to form a full circle. There are multiple ventilation holes and they are evenly distributed on the sheet body along the circumferential direction. The sheet sorting slots are connected to the rotor shaft holes.

[0017] According to another aspect of the present application, an embodiment of the present invention provides a permanent magnet motor, which includes the above-mentioned rotor punching sheet.

[0018] Compared with the prior art, the rotor punching of the present invention has at least the following beneficial effects:

[0019] The rotor punching provided by the present invention includes a sheet body and a synthetic magnetic pole, wherein the synthetic magnetic poles have an even number and are distributed circumferentially on the sheet body; the arc corresponding to the outer circular contour of each synthetic magnetic pole is eccentric to the axial hole of the sheet body, and the two ends of the arc respectively have a first notch and a second notch recessed inwardly, and the first notch and the second notch are symmetrical about the midpoint of the arc.

[0020] In the present invention, the arc of the outer circular contour of each synthetic magnetic pole is eccentric to the rotor shaft hole, and each arc has a first notch and a second notch symmetrically distributed, forming an uneven air gap distribution with a specific shape and a certain regular size. This is equivalent to a very clever pole cutting treatment on the rotor, which can optimize the sinusoidality of the air gap magnetic density, weaken the harmonics of each order and reduce the cogging torque, thereby improving the motor efficiency while reducing vibration and electromagnetic noise.

[0021] The permanent magnet motor provided by the present invention is designed based on the above-mentioned rotor punching sheets. Its beneficial effects refer to the beneficial effects of the above-mentioned rotor punching sheets, which will not be described in detail here.

[0022] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0024] Figure 1 is a schematic structural diagram of a rotor punching provided by an embodiment of the present invention;

[0025] Figure 2 It is a schematic diagram of a first structure of a single rotor magnetic pole in a rotor punching provided by an embodiment of the present invention;

[0026] Figure 3 is a schematic diagram of a second structure of a single rotor magnetic pole in a rotor punching provided by an embodiment of the present invention;

[0027] Figure 4 yes Figure 3 A partial enlarged view of the middle A;

[0028] Figure 5 is a third structural schematic diagram of a single rotor magnetic pole in a rotor punching provided by an embodiment of the present invention;

[0029] Figure 6 is a fourth structural schematic diagram of a single rotor magnetic pole in a rotor punching provided by an embodiment of the present invention;

[0030] Figure 7 is a fifth structural schematic diagram of a single rotor magnetic pole in a rotor punching provided by an embodiment of the present invention;

[0031] Figure 8 It is a structural schematic diagram of the cooperation between a third permanent magnet and a third magnet slot in a rotor punching provided by an embodiment of the present invention;

[0032] Fig. 9 is a sixth structural schematic diagram of a single rotor magnetic pole in a rotor punching provided by an embodiment of the present invention;

[0033] Fig.10 It is a structural schematic diagram of the cooperation between a first permanent magnet and a first magnet slot in a rotor punching provided by an embodiment of the present invention;

[0034] Fig.11 is a seventh structural schematic diagram of a single rotor magnetic pole in a rotor punching provided by an embodiment of the present invention;

[0035] Fig.12 is another structural schematic diagram of a rotor punching provided by an embodiment of the present invention;

[0036] Reference numerals:

[0037] 1. Sheet body; 11. Rivet hole; 12. Ventilation hole; 13. Sheet sorting slot; 14. Screw hole; 2. Composite magnetic pole; 21. First permanent magnet; 22. Second permanent magnet; 23. Third permanent magnet; 24. First magnet slot; 25. Second magnet slot; 26. Third magnet slot; 27. First magnetic isolation bridge; 28. Second magnetic isolation bridge; 29. ​​Third magnetic isolation bridge; 241. First semicircular slot; 242. Second semicircular slot; 243. Third oblique side gap; 244. First limiting boss; 251. Third semicircular slot; 252. Fourth semicircular slot; 253. Second limiting boss; 261. Fifth semicircular slot; 262. Sixth semicircular slot; 263. First oblique side gap; 264. Second oblique side gap; 265. Third limiting boss; 3. Arc; 31. First notch; 32. Second notch. DETAILED DESCRIPTION

[0038] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention application are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0039] In the description of the present invention, it should be clarified that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, but are not necessarily used to describe a specific order or sequence; the terms "vertical", "lateral", "longitudinal", "front", "rear", "left", "right", "up", "down", "horizontal", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, and do not mean that the referred device or element must have a specific direction or position, and therefore cannot be understood as a limitation on the present invention.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0042] Example 1

[0043] This embodiment provides a rotor punching sheet, such as Figure 1-Figure 12 As shown, the rotor punching includes a sheet body 1 and a synthetic magnetic pole 2, and the synthetic magnetic poles 2 have an even number, and the even number of the synthetic magnetic poles 2 are distributed circumferentially on the sheet body 1; the arc 3 corresponding to the outer circular contour of each synthetic magnetic pole 2 is eccentric to the axial hole of the sheet body 1, and the two ends of the arc 3 respectively have a first notch 31 and a second notch 32 recessed inwardly, and the first notch 31 and the second notch 32 are symmetrical about the midpoint of the arc 3.

[0044] Specifically, the sheet body 1 is a circular structure with an axial hole at its center. On the surface of the circular structure, there are an even number of synthetic magnetic poles 2 evenly distributed along the circumference. Figure 1The number of the composite magnetic poles 2 is eight, and of course it can also be six or ten, etc., which is not specifically limited here. The outer contour of the composite magnetic pole 2 forms an arc 3, and the arc 3 is eccentric to the axial hole of the sheet body 1, that is, the centers of the circles corresponding to the two do not coincide. In addition, at both ends of the arc 3, there are a first notch 31 and a second notch 32 that are recessed toward the center of the sheet body 1, and the first notch 31 and the second notch 32 are symmetrical about the midpoint of the arc 3.

[0045] In this embodiment, the arc 3 of the outer contour of each composite magnetic pole 2 is eccentric to the rotor shaft hole, such as Figure 4 As shown, each arc 3 has a symmetrically distributed first notch 31 and a second notch 32, forming an uneven air gap distribution of a specific shape and a certain regular size, which is equivalent to a very clever pole clipping treatment of the rotor, which can optimize the sinusoidality of the air gap magnetic density, weaken the harmonics of each order and reduce the cogging torque, thereby improving the motor efficiency while reducing vibration and electromagnetic noise.

[0046] More specifically, pole trimming treatment of the rotor can optimize the shape of the permanent magnet, making it closer to a sine waveform, thereby reducing the high-order harmonic content in the air gap magnetic flux density; it can effectively reduce the total harmonic distortion rate of the air gap magnetic field, thereby reducing the vibration, noise and iron loss of the motor and improving the overall performance of the motor; pole trimming treatment can also reduce the cogging torque and torque pulsation by optimizing the shape of the magnetic poles; through pole trimming treatment, the waveform of the air gap magnetic field can also be designed to be closer to the ideal sine waveform. In short, pole trimming treatment can significantly improve the sinusoidality of the air gap magnetic flux density, improve motor performance and reduce vibration and noise by optimizing the shape and thickness of the permanent magnet and reducing the harmonic content in the air gap magnetic field.

[0047] In a specific embodiment, the synthetic magnetic pole 2 includes a first magnet slot 24, a second magnet slot 25 and a third magnet slot 26, the first magnet slot 24 and the second magnet slot 25 are arranged obliquely in different directions, there is a first distance between the first ends of the first magnet slot 24 and the second magnet slot 25, there is a second distance between the second ends of the first magnet slot 24 and the second magnet slot 25, the first distance is greater than the second distance, and the first ends of the first magnet slot 24 and the second magnet slot 25 are facing the edge of the sheet 1, and the third magnet slot 26 is arranged between the first ends of the first magnet slot 24 and the second magnet slot 25.

[0048] More specifically, the first magnet slot 24 and the second magnet slot 25 are arranged obliquely in different directions to form a V-shaped structure. Different from the V-shaped structure, the second end of the first magnet slot 24 and the second end of the second magnet slot 25 do not contact each other, and there is a second distance between them. The first end of the first magnet slot 24 and the first end of the second magnet slot 25 face the edge of the sheet 1, and there is a first distance between them. The first distance is greater than the second distance, and the third magnet slot 26 is arranged between the first ends of the first magnet slot 24 and the second magnet slot 25, that is, it is arranged in a space with a larger distance.

[0049] In a specific embodiment, the synthetic magnetic pole 2 also includes a first permanent magnet 21, a second permanent magnet 22 and a third permanent magnet 23. The first permanent magnet 21 is arranged in the first magnet slot 24, the second permanent magnet 22 is arranged in the second magnet slot 25, and the third permanent magnet 23 is arranged in the third magnet slot 26.

[0050] Due to the positional relationship between the first magnet slot 24, the second magnet slot 25 and the third magnet slot 26, the first permanent magnet 21, the second permanent magnet 22 and the third permanent magnet 23 also have similar structural shapes. This shape makes the excitation of the permanent magnet more concentrated, thereby reducing leakage flux and improving the magnetic resistance and efficiency of the motor.

[0051] In addition, the first magnet slot 24, the second magnet slot 25 and the third magnet slot 26 all have limiting bosses; specifically, the first magnet slot 24 has a first limiting boss 244, the second magnet slot 25 has a second limiting boss 253, and the third magnet slot 26 has a third limiting boss 265. The limiting bosses limit the force applied to the permanent magnets by contacting with the permanent magnets, thereby preventing the permanent magnets from being thrown out during the rotation of the rotor core. This design can effectively avoid the problem of magnets falling off due to centrifugal force or other external forces. In addition, the design of the limiting boss can also optimize the magnetic circuit of the motor, reduce magnetic leakage, and thus improve the efficiency of the motor.

[0052] like Figure 6 As shown, the width a1 of the third magnet slot 26 and the width a2 of the first magnet slot 24 and the second magnet slot 25 satisfy: a1=k a ×a2,k a =0.5~1. First, the width of the magnet slot directly affects the size of the cogging torque. Appropriately limiting the width of the magnet slot can effectively reduce the cogging torque, thereby improving the running stability and efficiency of the motor. Second, the width of the magnet slot affects the distribution of the air gap magnetic field. By reasonably limiting the slot width, the high-order harmonics in the air gap magnetic field can be reduced, thereby reducing torque fluctuations and improving the electromagnetic performance of the motor.

[0053] In a specific embodiment, a first magnetic isolation bridge 27 is formed between the first magnetic slot 24 and the edge of the sheet 1, and between the second magnetic slot 25 and the edge of the sheet 1, and the distance between the side of the first magnetic slot 24 close to the edge of the sheet 1 and the edge of the sheet 1 is 0.5mm-1.5mm; a second magnetic isolation bridge 28 is formed between the third magnetic slot 26 and the edge of the sheet 1, and the distance between the side of the second magnetic slot 25 close to the edge of the sheet 1 and the edge of the sheet 1 is 0.5mm-1.5mm; a third magnetic isolation bridge 29 is formed between the first magnetic slot 24 and one end of the second magnetic slot 25 away from the edge of the sheet 1, and the distance between the end of the first magnetic slot 24 away from the edge of the sheet and the end of the second magnetic slot 25 away from the edge of the sheet 1 is 0.5mm-3mm.

[0054] The above distances correspond to the thickness of the first magnetic isolation bridge 27, the second magnetic isolation bridge 28 and the third magnetic isolation bridge 29. Firstly, the appropriate magnetic isolation bridge thickness can enhance the mechanical strength of the rotor and prevent the material from yielding or breaking due to centrifugal force during high-speed rotation; secondly, by reasonably designing the thickness of the magnetic isolation bridge, it is possible to reduce magnetic leakage while maintaining sufficient mechanical strength, thereby taking into account both electromagnetic performance and mechanical strength; and, by optimizing the design of the magnetic isolation bridge, the iron loss and electromagnetic force of the motor can be reduced, thereby improving the motor efficiency and improving the Nvh performance.

[0055] The upper end of the third magnetic isolation bridge 29 is in a right angle shape. The right angle magnetic isolation bridge can effectively limit the leakage flux, thereby improving the efficiency and performance of the motor. It can also enhance the overall mechanical strength of the rotor punching to prevent deformation when running at high speed or under the action of centrifugal force. In addition, the third magnetic isolation bridge 29 is made longer by two horizontal line segments, so that the anti-leakage magnetic effect is improved. Thereby reducing the torque pulsation of the motor.

[0056] In a specific embodiment, the bottom of both sides of the first magnet slot 24 has a first semicircular slot 241 and a second semicircular slot 242, wherein the first semicircular slot 241 is close to the edge of the sheet 1; the bottom of both sides of the second magnet slot 25 has a third semicircular slot 251 and a fourth semicircular slot 252, wherein the third semicircular slot 251 is close to the edge of the sheet 1; the bottom of both sides of the third magnet slot 26 has a fifth semicircular slot 261 and a sixth semicircular slot 262, respectively; the radius of the fifth semicircular slot 261 and the sixth semicircular slot 262 is 0.15mm-1mm, the radius of the first semicircular slot 241 and the third semicircular slot 251 is 0.2mm-1.5mm, and the radius of the second semicircular slot 242 and the fourth semicircular slot 252 is 0.15mm-1mm. In addition, the radius of the second semicircular slot 242 is smaller than the radius of the first semicircular slot 241, and the radius of the fourth semicircular slot 252 is smaller than the radius of the third semicircular slot 251.

[0057] More specifically, the first magnet slot 24 and the second magnet slot 25 have the same structure. The main outline of the first magnet slot 24 is a quadrilateral, the two long sides are the first side and the second side, and the two short sides are the third side and the fourth side. The second side is the side away from the third magnet slot 26, and the first semicircular slot 241 and the second semicircular slot 242 are extended from both ends of the second side in the direction away from the third magnet slot 26. The third side is the side close to the edge of the sheet 1, and the third side extends an upper limit step in the direction close to the edge of the sheet 1, and the fourth side extends a lower limit boss in the direction away from the edge of the sheet 1, and the upper limit boss and the lower limit boss are the above-mentioned first limit boss 244.

[0058] The general outline of the third magnet slot 26 is also a quadrilateral, with two long sides respectively being the fifth side and the sixth side, and two short sides respectively being the seventh side and the eighth side, wherein the fifth side is a side close to the edge of the sheet body 1, and the two sides of the sixth side extend toward the center to form the fifth semicircular slot 261 and the sixth semicircular slot 262. The seventh side and the eighth side extend toward both sides respectively to form a left limiting boss and a right limiting boss, and the left limiting boss and the right limiting boss are the third limiting boss 265 mentioned above.

[0059] like Fig. 9 and Fig.10 As shown, the upper end of the first magnet slot 24 away from the sheet body 1 has a third oblique side gap 243, and the length x2 of the projection of the third oblique side gap 243 on the reference plane satisfies: x2=k x '×b2, where k x '=0.1~0.3, b2 is the distance between the first semicircular groove 241 and the second semicircular groove 242, and b1 and b2 satisfy: b1=k b ×b2,k b =0.5~1; the angle j2 between the third oblique side gap 243 and the reference plane satisfies: j2=0.3~30°, wherein the reference plane is the inclined surface of the second permanent magnet 22;

[0060] For a clearer explanation, the first side, second side, third side and fourth side mentioned above are still used. At one end of the first side away from the edge of the sheet 1 , the end of the first side is inclined outwards, so that the third oblique side gap 243 is formed between the first side and the first permanent magnet 21 .

[0061] The upper end of the second magnet slot 25 away from the sheet body 1 has a fourth oblique side gap, and the fourth oblique side gap has the same length and inclination angle as the third oblique side gap 243 .

[0062] In a specific embodiment, Figure 7 and Figure 8As shown, the upper sides of the third magnet slot 26 have symmetrically distributed first oblique side gaps 263 and second oblique side gaps 264, and the distance x1 between the ends of the first oblique side gaps 263 and the second oblique side gaps 264 close to each other satisfies: x1=k x ×b1, where k x =0.5~0.9, b1 is the distance between the fifth semicircular groove 261 and the sixth semicircular groove 262, and the angle j1 between the first oblique side gap 263 and the second oblique side gap 264 and the horizontal plane satisfies: j1=0.3~30°.

[0063] For a clearer explanation, the fifth, sixth, seventh and eighth sides mentioned above are continued to be used, and both sides of the fifth side are respectively inclined toward the edge of the sheet body 1, so that the first oblique side gap 263 and the second oblique side gap 264 are formed between the side and the third permanent magnet 23.

[0064] The magnet slots on the rotor punching sheets are provided with semicircular grooves and oblique side gaps, so that the local magnetic permeability of these parts changes, thereby changing the magnetic field distribution form of the permanent magnet, which is conducive to weakening the harmonic components of a specific order. In addition, local demagnetization of permanent magnets often occurs at four corners, and the most effective way for permanent magnets to resist demagnetization is to increase the thickness, but this will significantly increase the cost. The above-mentioned design of the permanent magnet slots in this embodiment can effectively enhance the magnetic resistance of this part, so that the demagnetization magnetic potential is offset, and the anti-demagnetization ability of the permanent magnet is improved, thereby achieving the purpose of saving the amount of magnetic steel, so that the manufacturing material cost of the motor can be reduced.

[0065] In a specific embodiment, the eccentricity d between the arc 3 corresponding to the outer contour of each synthetic magnetic pole 2 and the axial hole of the sheet 1 satisfies: d=k d ×r0, where k d =0.15~0.55; the radius r1 of the arc 3 corresponding to the outer contour of the synthetic magnetic pole 2 and the diameter r0 of the sheet 1 satisfy: r1=k r ×r0,k r =0.5~0.9. In this embodiment, by adjusting the eccentricity, the distribution of the air gap magnetic field can be changed, thereby reducing the air gap magnetic density harmonics, making the radial air gap magnetic flux density waveform closer to the sine waveform, and thus improving the electromagnetic performance of the motor. In addition, the design of the eccentricity can effectively reduce the cogging torque and reduce the torque fluctuation, thereby improving the stability and reliability of the motor operation.

[0066] In a specific embodiment, the first notch 31 and the second notch 32 are uniform arcs, and their corresponding radius r2 satisfies: r2=k r '×r1,k r'=0.02~0.4; and the first notch 31 and the second notch 32 are connected to the outer circular contour of the synthetic magnetic pole 2 through a transition arc.

[0067] In addition, the intersections between the first notch 31 and the second notch 32 and the arc of the outer contour of the magnetic pole are also rounded.

[0068] In a specific embodiment, the sheet body 1 has a rivet hole 11, a ventilation hole 12, a sheet sorting slot 13 and a screw through hole 14. There are at least two rivet holes 11 and screw through holes 14, and the two are cross-arranged to form a full circle. There are multiple ventilation holes 12 and they are evenly distributed along the circumferential direction on the sheet body 1. The sheet sorting slot 13 is connected to the rotor shaft hole.

[0069] The rivet holes 11 can stack and rivet multiple rotor punchings into a rotor core, which is used in permanent magnet motors. The shape of the ventilation holes 12 can be circular, elongated, U-shaped or other irregular shapes. These holes are usually evenly distributed along the circumferential direction to ensure the symmetry and efficiency of air circulation. The main function of the ventilation holes 12 is to reduce the temperature rise of the key parts of the motor by forced cooling, thereby improving the heat dissipation effect and operating efficiency of the motor. The sheet sorting groove 13 can be used as a reference point for positioning the punching unit to ensure that the punching maintains the correct orientation and position during the stacking process. The sheet sorting groove 13 can also play an important role in the subsequent motor assembly process. In the automatic sheet sorting device, the design of the sheet sorting groove 13 helps to sort the stacked rotor punchings, reduce the labor intensity of manual operation, and prevent the punchings from being damaged or generating noise during the falling process. The sheet sorting groove 13 in this embodiment is semicircular, and of course, the sheet sorting groove 13 can also be other shapes. The screw perforation 14 is used for the installation of the rotor end plate.

[0070] In addition, a keyway is provided on the shaft hole of the rotor. The main function of the keyway on the shaft hole of the rotor is to install a key to achieve circumferential fixation and torque transmission between the rotor core and the rotor shaft. The design of the keyway and the cooperation of the key can ensure that the rotor will not slide relative to each other during rotation, thereby ensuring the stability and reliability of the mechanical system.

[0071] In addition, in order to make the rotor punching provided in this embodiment applicable to the rotor with two-section oblique poles, the rivet holes 11, ventilation holes 12, sheet sorting slots 13 and screw holes 14 can be arranged by rotating a specific oblique pole angle, such as Fig.12 shown.

[0072] The rotor punching provided in this embodiment can effectively form an air gap magnetic field with high magnetic density and high sinusoidality, and has the advantages of high power density, low electromagnetic vibration noise, and small cogging torque.

[0073] Example 2

[0074] This embodiment provides a permanent magnet motor, which includes the rotor punching sheet described in Embodiment 1.

[0075] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A rotor punching, characterized in that: The rotor punching includes a sheet body and a synthetic magnetic pole, wherein the synthetic magnetic poles have an even number and are distributed circumferentially on the sheet body; the arc corresponding to the outer circular contour of each synthetic magnetic pole is eccentric to the axial hole of the sheet body, and the two ends of the arc respectively have a first notch and a second notch recessed inwardly, and the first notch and the second notch are symmetrical about the midpoint of the arc.

2. The rotor punching according to claim 1, characterized in that: The composite magnetic pole includes a first magnet slot, a second magnet slot and a third magnet slot, wherein the first magnet slot and the second magnet slot are arranged obliquely in different directions, a first distance is provided between the first ends of the first magnet slot and the second magnet slot, a second distance is provided between the second ends of the first magnet slot and the second magnet slot, the first distance is greater than the second distance, and the first ends of the first magnet slot and the second magnet slot face the edge of the sheet, and the third magnet slot is provided between the first ends of the first magnet slot and the second magnet slot.

3. The rotor punching according to claim 2, characterized in that: The composite magnetic pole further comprises a first permanent magnet, a second permanent magnet and a third permanent magnet, wherein the first permanent magnet is arranged in the first magnet slot, the second permanent magnet is arranged in the second magnet slot, and the third permanent magnet is arranged in the third magnet slot; the first magnet slot, the second magnet slot and the third magnet slot are all provided with a limiting boss; And / or the width a1 of the third magnet slot and the width a2 of the first magnet slot and the second magnet slot satisfy: a1=k a ×a2,k a =0.5~1.

4. The rotor punching according to claim 3, characterized in that: A first magnetic isolation bridge is formed between the first magnetic groove and the edge of the sheet, and between the second magnetic groove and the edge of the sheet, and the distance between the side of the first magnetic groove close to the edge of the sheet and the edge of the sheet is 0.5mm-1.5mm; a second magnetic isolation bridge is formed between the third magnetic groove and the edge of the sheet, and the distance between the side of the second magnetic groove close to the edge of the sheet and the edge of the sheet is 0.5mm-1.5mm; a third magnetic isolation bridge is formed between the first magnetic groove and the end of the second magnetic groove away from the edge of the sheet, and the distance between the end of the first magnetic groove away from the edge of the sheet and the end of the second magnetic groove away from the edge of the sheet is 0.5mm-3mm; and / or the upper end of the third magnetic isolation bridge is at a right angle.

5. The rotor punching according to claim 3, characterized in that: The bottom of both sides of the first magnet groove respectively has a first semicircular groove and a second semicircular groove, wherein the first semicircular groove is close to the edge of the sheet; the bottom of both sides of the second magnet groove respectively has a third semicircular groove and a fourth semicircular groove, wherein the third semicircular groove is close to the edge of the sheet; the bottom of both sides of the third magnet groove respectively has a fifth semicircular groove and a sixth semicircular groove; the radius of the fifth semicircular groove and the sixth semicircular groove is 0.15mm-1mm, the radius of the first semicircular groove and the third semicircular groove is 0.2mm-1.5mm, and the radius of the second semicircular groove and the fourth semicircular groove is 0.15mm-1mm.

6. The rotor punching according to claim 5, characterized in that: The two sides of the upper side of the third magnet slot have a symmetrically distributed first oblique side gap and a second oblique side gap, and the distance x1 between the ends of the first oblique side gap and the second oblique side gap close to each other satisfies: x1=k x ×b1, where k x =0.5-0.9, b1 is the distance between the fifth semicircular groove and the sixth semicircular groove, and the angle j1 between the first oblique side gap and the second oblique side gap and the horizontal plane satisfies: j1=0.3-30°; The upper end of the first magnet slot away from the sheet body has a third oblique side gap, and the length x2 of the projection of the third oblique side gap on the reference plane satisfies: x2=k x '×b2, where k x '=0.1~0.3, b2 is the distance between the first semicircular groove and the second semicircular groove, and b1 and b2 satisfy: b1=k b ×b2,k b =0.5~1; the angle j2 between the third oblique side gap and the reference plane satisfies: j2=0.3~30°, wherein the reference plane is the inclined surface of the second permanent magnet; The upper end of the second magnet slot away from the sheet body has a fourth oblique side gap, and the fourth oblique side gap has the same length and inclination angle as the third oblique side gap.

7. The rotor punching according to any one of claims 4 to 6, characterized in that: The eccentricity d between the arc corresponding to the outer contour of each synthetic magnetic pole and the axial hole of the sheet body satisfies: d=k d ×r0, where k d =0.15~0.55; the radius r1 of the arc corresponding to the outer contour of the synthetic magnetic pole and the diameter r0 of the sheet body satisfy: r1=k r ×r0,k r =0.5~0.

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8. The rotor punching according to claim 7, characterized in that: The first notch and the second notch are uniform arcs, and the corresponding radius r2 satisfies: r2=k r '×r1,k r '=0.02~0.4; and the first notch and the second notch are connected to the outer circular contour of the synthetic magnetic pole through a transition arc.

9. The rotor punching according to any one of claims 1 to 6, characterized in that: The sheet body is provided with rivet holes, ventilation holes, sheet sorting slots and screw through holes. There are at least two rivet holes and screw through holes, and the two are cross-arranged to form a full circle. There are multiple ventilation holes and they are evenly distributed on the sheet body along the circumferential direction. The sheet sorting slots are connected to the rotor shaft holes.

10. A permanent magnet motor, characterized in that: The permanent magnet motor comprises the rotor punching sheet according to any one of claims 1-9.

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