Rotor punching sheet of unipolar motor and unipolar motor

Abstract

At least two magnetic steel grooves are formed in the end face of the rotor punching sheet in the circumferential direction at intervals, a plurality of arc-shaped magnetic circuit guiding grooves are formed in the two ends of each magnetic steel groove respectively, the magnetic circuit guiding grooves are located in the inner sides of the magnetic steel grooves, the magnetic circuit guiding grooves are bent in the direction of the magnetic steel grooves, and the magnetic circuit guiding grooves are bent in the direction of the magnetic steel grooves. The plurality of magnetic circuit guiding grooves are arranged at intervals along the radial direction of the rotor punching sheet, and the widths of the cross sections of the plurality of magnetic circuit guiding grooves at one end of the magnetic steel groove are gradually reduced along the direction close to the center of the rotor punching sheet. Two ends of each magnetic steel groove are respectively provided with a plurality of arc-shaped magnetic circuit guide grooves, and the widths of the plurality of magnetic circuit guide grooves are gradually reduced along the direction of the center of the rotor punching sheet, so that magnetic lines can be guided from permanent magnet poles to silicon steel poles, the conduction path of the magnetic lines is prolonged, the magnetic resistance of the silicon steel poles is matched with that of the permanent magnet poles, and the salient pole ratio is increased; the reluctance torque is improved, and the torque reduction caused by the reduction of the use amount of the magnetic steel is made up.

Description

Technical Field

[0001] This invention relates to a rotor lamination for a unipolar motor and the unipolar motor itself. Background Technology

[0002] Compared to traditional permanent magnet motors, alternating pole motors can reduce the number of magnets by half, but this also leads to a decrease in torque and an increase in vibration and noise. To address these issues, regarding the torque reduction: existing solutions include using an external rotor to overcome the torque decrease caused by reducing permanent magnet poles (CN 220527754 U), combining internal and external permanent magnets to increase torque (CN 107425630 B), and increasing the salient pole ratio to increase torque (CN205017194 U). Regarding the reduction of vibration and noise: there are solutions such as opening air slots in the rotor to reduce harmonics in the back EMF (CN 110401282 B, CN 110401283 B), solutions such as using series and parallel connection of tangential magnetic circuits and radial magnetic circuits to reduce rotational fluctuations (CN 205407445 U), and solutions such as opening slots to improve the magnetic field symmetry of permanent magnet poles and alternating poles, thereby reducing the second harmonic distortion rate of the back EMF (CN 107124054 B) to reduce torque pulsation and losses.

[0003] In existing solutions, slotting the rotor reduces harmonic content and torque ripple, but it also reduces effective torque, leading to a decline in the overall performance of the motor. Furthermore, due to magnetic circuit asymmetry, single-pole motors introduce even-order harmonics (2, 4, 6...) in addition to odd-order harmonics (5th, 7th, 11th, 13th...), making vibration and noise more complex. Simply optimizing one objective cannot comprehensively improve motor performance. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects in the prior art and provide a rotor lamination for a unipolar motor and a unipolar motor.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] A rotor lamination for a unipolar motor, wherein at least two magnetic slots are spaced apart circumferentially on the end face of the rotor lamination, and multiple arc-shaped magnetic circuit guide slots are respectively provided at both ends of each magnetic slot. The magnetic circuit guide slots are located inside the magnetic slots and are curved toward the magnetic slots. The multiple magnetic circuit guide slots are spaced apart along the radial direction of the rotor lamination. Among the multiple magnetic circuit guide slots located at one end of the magnetic slots, the cross-sectional width of the magnetic circuit guide slots gradually decreases along the direction close to the center of the rotor lamination.

[0007] In this design, the rotor lamination is used for a unipolar motor, and the magnet slots are used to install permanent magnets. The permanent magnets installed in all the magnet slots on the rotor lamination have the same polarity, forming alternating silicon steel poles and permanent magnet poles on the outer circumference of the rotor lamination. By setting multiple arc-shaped magnetic circuit guide slots at both ends of the magnet slots, and the width of the magnetic circuit guide slots gradually decreases along the direction of the center of the rotor lamination, the magnetic lines of force can be guided from the permanent magnet poles to the silicon steel poles, extending the transmission path of the magnetic lines of force, making the magnetic reluctance of the silicon steel poles and the permanent magnet poles match, increasing the saliency ratio, improving the magnetic reluctance torque, and compensating for the torque drop caused by the reduction in the amount of magnets. Furthermore, setting the magnetic circuit guide slots to be arc-shaped can improve the sinusoidal nature of the air gap magnetic field, reduce torque fluctuations, and thus reduce vibration noise. In addition, the multiple arc-shaped magnetic circuit guide slots also play a role in magnetic isolation, preventing the magnetic lines of force from being transmitted in a straight line from the permanent magnet poles to the motor shaft at the center of the rotor lamination, thus preventing leakage magnetic field and suppressing harmonic amplitude.

[0008] Preferably, the magnetic circuit guide slots located at both ends of the magnet slot are symmetrical with respect to the axis of symmetry passing through the center of the rotor lamination.

[0009] In this scheme, the above-mentioned structural configuration is adopted to improve the symmetry of the magnetic flux density distribution of adjacent silicon steel poles, so as to match the magnetic reluctance characteristics of silicon steel poles and permanent magnet poles and improve uniformity.

[0010] Preferably, the end of the magnetic circuit guide groove near the magnet slot is the first end, and the end of the magnetic circuit guide groove near the outer edge of the rotor lamination is the second end. The width of the magnetic circuit guide groove along the radial direction of the rotor lamination gradually decreases from the first end to the second end.

[0011] In this design, the width of the magnetic circuit guide slot along the radial direction of the rotor lamination gradually decreases from the first end to the second end, causing the width of the magnetic bridge formed between adjacent magnetic circuit guide slots to also gradually decrease along its circumferential direction. That is, the width of the magnetic bridge gradually increases from the end near the magnet slot to the end near the silicon steel pole, balancing the magnetic flux density distribution on the magnetic bridge and ensuring that the magnetic flux density at each point is close to approximately 1.7T, thus fully utilizing the properties of the magnetically conductive material.

[0012] Preferably, the number of magnetic circuit guide slots is three, and the three magnetic circuit guide slots are respectively the first magnetic circuit guide slot, the second magnetic circuit guide slot and the third magnetic circuit guide slot along the direction close to the center of the rotor lamination.

[0013] In this design, the aforementioned structural arrangement forms two magnetic bridges between the three magnetic circuit guide slots. This facilitates the convergence of magnetic lines of force, allowing them to be conducted along these bridges. This enhances the sinusoidal nature of the air gap magnetic field, increases reluctance torque, compensates for the torque decrease caused by the reduced amount of magnets, and increases the saliency ratio. Simultaneously, the magnetic circuit guide slots also prevent magnetic leakage. Furthermore, the three magnetic circuit guide slots can increase the motor torque by more than 5%.

[0014] Preferably, the distance from one end of the first magnetic circuit guide groove to the outer edge of the rotor lamination is H1, the distance from one end of the second magnetic circuit guide groove to the outer edge of the rotor lamination is H2, and the distance from one end of the third magnetic circuit guide groove to the outer edge of the rotor lamination is H3. ;

[0015] And / or, the distance between the other end of the first magnetic circuit guide groove and the magnetic steel groove is H5, the distance between the other end of the second magnetic circuit guide groove and the magnetic steel groove is H6, and the distance between one end of the third magnetic circuit guide groove and the magnetic steel groove is H7. .

[0016] In this scheme, setting the distance H1 between one end of the first magnetic circuit guide groove and the outer edge of the rotor lamination to be equal to the distance H2 between one end of the second magnetic circuit guide groove and the outer edge of the rotor lamination ensures that the strength between the silicon steel pole and the permanent magnet pole meets the requirements, while also guiding the magnetic lines of force effectively. Setting the distance H3 between one end of the third magnetic circuit guide groove and the outer edge of the rotor lamination to be greater than H1 or H2 ensures both the strength of the middle part of the silicon steel pole and a good magnetic shielding effect.

[0017] The distance H5 between the other end of the first magnetic circuit guide groove and the magnetic steel groove is set to be less than H6 or H7, and the distance H6 between the other end of the second magnetic circuit guide groove and the magnetic steel groove is set to be equal to the distance H7 between one end of the third magnetic circuit guide groove and the magnetic steel groove. This is mainly used to extend the transmission path of the magnetic lines of force and reduce inter-pole leakage and end-face leakage.

[0018] Preferably, the distance between one end of the first magnetic circuit guide groove and the outer edge of the rotor lamination is H1, and the value of H1 ranges from 0.4 to 0.6 mm; the distance between the other end of the first magnetic circuit guide groove and the magnet slot is H5, and the value of H5 ranges from 0.5 to 0.6 mm.

[0019] And / or, the distance from one end of the second magnetic circuit guide groove to the outer edge of the rotor lamination is H2, the value of H2 is equal to the value of H1, and the distance from the other end of the second magnetic circuit guide groove to the magnet slot is H6, the value of H6 is in the range of 1.1~1.3mm;

[0020] And / or, the distance from one end of the third magnetic circuit guide groove to the outer edge of the rotor lamination is H3, and the value of H3 is in the range of (1.3~1.5)*H2, and the distance from one end of the third magnetic circuit guide groove to the magnet slot is H7, and the value of H7 is in the range of 1~1.2mm.

[0021] In this design, the thicknesses of the rotor laminations at both ends of the first magnetic circuit guide groove are H1 and H5, respectively. The range of H1 is 0.4~0.6mm, and the range of H5 is 0.5~0.6mm. This ensures that the magnetic lines of force of the permanent magnet poles reach the silicon steel poles through H5 and H1, while also taking into account the magnetic isolation effect of the first magnetic circuit guide groove to prevent magnetic leakage. It also ensures that the rotor laminations have sufficient strength to prevent the problem of local weakness caused by excessively large openings.

[0022] The rotor laminations have thicknesses of H2 and H6 at both ends of the second magnetic circuit guide groove, respectively. The value of H2 is set to be equal to the value of H1, that is, the value range of H2 is 0.4~0.6mm, and the value range of H6 is 1.1~1.3mm. This ensures that the magnetic lines of force of the permanent magnet poles reach the silicon steel poles through H6 and H2, while also taking into account the magnetic isolation effect of the second magnetic circuit guide groove to prevent magnetic leakage. It also ensures that the rotor laminations have sufficient strength to prevent the problem of local weakness caused by excessively large openings.

[0023] The thicknesses of the rotor laminations at both ends of the third magnetic circuit guide groove are H3 and H7, respectively. The value of H3 ranges from (1.3~1.5)*H2 mm, and the value of H7 ranges from 1~1.2 mm. This ensures that the magnetic lines of force of the permanent magnet poles reach the silicon steel poles through H3 and H7, while also taking into account the magnetic isolation effect of the third magnetic circuit guide groove to prevent magnetic leakage. It also ensures that the rotor laminations have sufficient strength to prevent the problem of local weakness caused by excessively large openings.

[0024] Preferably, the third magnetic circuit guide groove includes a first arc segment and a second arc segment that are not concentrically arranged, the first arc segment and the second arc segment forming the third magnetic circuit guide groove, and the radius of the first arc segment is within the range of... mm, of which, P is the number of magnet slots. Let be the radius of the rotor lamination, and let the radius of the second arc segment range from . mm;

[0025] And / or, the second magnetic circuit guide groove includes a third arc segment and a fourth arc segment that are not concentrically arranged, the third arc segment and the fourth arc segment forming the second magnetic circuit guide groove, and the radius of the third arc segment being within the range of... mm, the radius of the fourth arc segment ranges from 100 mm to 100 mm. mm, of which, P represents the number of magnet slots, and Z represents the number of stator teeth that mate with the rotor laminations. The greatest common divisor of 2P and Z is... It is the least common multiple of 2P and Z;

[0026] And / or, the first magnetic circuit guide groove includes a fifth arc segment and a sixth arc segment that are not concentrically arranged, the fifth arc segment and the sixth arc segment forming the first magnetic circuit guide groove, and the radius of the fifth arc segment being within the range of... mm, the radius of the sixth arc segment ranges from 100 mm to 100 mm. mm, of which, P represents the number of magnet slots, and Z represents the number of stator teeth that mate with the rotor laminations. The greatest common divisor of 2P and Z is... It is the least common multiple of 2P and Z.

[0027] In this design, the third magnetic circuit guide groove includes a first arc segment and a second arc segment that are not concentrically arranged, facilitating the formation of a third magnetic circuit guide groove with a gradually changing width. The radius of the first arc segment is set to a range of values. mm, the range of values ​​for the radius of the second arc segment is set to mm, so that the shape and size of the third magnetic circuit guide slot are related to the radius of the rotor lamination. The radius of the first arc segment can be obtained by adjusting the radius of the rotor lamination and the number of magnet slots, which is related to the number of magnet slots P. This allows users to design third magnetic circuit guide slots of different sizes.

[0028] The second magnetic circuit guide groove includes a third and fourth circular arc segments that are not concentrically arranged, which facilitates the formation of a second magnetic circuit guide groove with a gradually changing width. The radius of the third circular arc segment is set to a range of values. mm, the range of values ​​for the radius of the fourth arc segment is set to mm, which links the shape and size of the second magnetic circuit guide slot to the third magnetic circuit guide slot. Adjusting the parameters of the third magnetic circuit guide slot correspondingly adjusts the parameters of the second magnetic circuit guide slot. Where P is the number of magnet slots, and Z is the number of stator teeth used in conjunction with the rotor laminations. It is the least common multiple of 2P and Z. It is the greatest common divisor of 2P and Z.

[0029] The first magnetic circuit guide groove includes a fifth and a sixth circular arc segment that are not concentrically arranged, which facilitates the formation of a first magnetic circuit guide groove with a gradually changing width. The radius of the fifth circular arc segment is set to a range of values. mm, the range of values ​​for the radius of the sixth arc segment is set to mm, so that the shape and size of the second magnetic circuit guide slot are linked to the third magnetic circuit guide slot through the second magnetic circuit guide slot. When the parameters of the third magnetic circuit guide slot are adjusted, the parameters of the second and first magnetic circuit guide slots are adjusted accordingly. Where P is the number of magnet slots, and Z is the number of stator teeth used in conjunction with the rotor laminations. The greatest common divisor of 2P and Z is... It is the least common multiple of 2P and Z.

[0030] Preferably, a preset area is provided on the end face of the rotor lamination, and the preset area is provided at both ends of the magnet slot. The preset area is enclosed by the outer boundary of the rotor lamination, the extension line of the sixth arc segment, and the extension line of the end face of the magnet slot. A plurality of magnetic isolation holes are provided in the preset area, and the ratio of the area of ​​the plurality of magnetic isolation holes to the area of ​​the preset area is in the range of 0.2 to 0.5.

[0031] In this scheme, the above-mentioned parameter structure settings can reduce magnetic leakage at the end of the magnet slot and improve the reluctance torque.

[0032] Preferably, the magnetic circuit guide groove is arc-shaped, and the centers of all the magnetic circuit guide grooves located at one end of the magnet groove are located within a preset circular area. Furthermore, the angle between the line connecting the center of the circular area and the center of the rotor lamination and the axis of symmetry is [value missing]. Where P is the number of the magnetic steel grooves;

[0033] And / or, the magnetic circuit guide groove is arc-shaped, and the center of the magnetic circuit guide groove is located on the outside of the rotor lamination.

[0034] In this design, the arc-shaped magnetic circuit guide groove ensures that the width of the magnetic circuit guide groove gradually changes along its circumferential direction. Correspondingly, a magnetic bridge is obtained between adjacent magnetic circuit guide grooves, which facilitates the conduction and convergence of magnetic lines of force. The magnetic lines of force are conducted along the magnetic bridge, and the propagation path is blocked at the position of the magnetic circuit guide groove. This increases the sinusoidality of the air gap magnetic field, improves the reluctance torque, compensates for the torque decrease caused by the reduction in the amount of magnets, increases the saliency ratio, and at the same time, the magnetic circuit guide groove can also avoid magnetic leakage.

[0035] Preferably, the diameter of the preset central region can be set according to user needs. Preferably, the diameter of the preset central region is no greater than 1 mm.

[0036] In an alternative design, the magnetic circuit guide groove is part of an ellipse, which can also guide the magnetic lines of force to the silicon steel pole in a predetermined direction.

[0037] The center of the magnetic circuit guide groove is located on the outside of the rotor lamination, which can obtain a larger arc segment, and thus a larger magnetic circuit guide groove.

[0038] In an alternative approach, the center of the magnetic circuit guide groove is located inside the rotor lamination, which allows for a smaller arc segment and thus a smaller magnetic circuit guide groove.

[0039] Preferably, the outer peripheral surface of the rotor lamination has a groove, and each of the magnet slots has a groove at both ends, with the grooves at the two ends of the magnet slot having different sizes.

[0040] In this scheme, one permanent magnet is installed on the adjacent magnetic poles of the unipolar motor, while the other is not. Since the permanent magnet has a constraining effect on the magnetic lines of force, the magnetic flux density distribution of the adjacent magnetic poles is asymmetrical. By setting grooves of different sizes at both ends of the magnetic steel groove, the magnetic flux density distribution of the permanent magnet poles can be balanced, making the magnetic flux density of the adjacent magnetic poles more symmetrical. By weakening the position of each harmonic peak, the odd and even harmonics in the air gap magnetic flux density are reduced, thereby reducing the back EMF harmonic content and reducing torque ripple.

[0041] Furthermore, since the rotor laminations have a rotation direction, the permanent magnet has an entry end and an exit end. Due to the influence of armature reaction and magnetic permeability changes, when the rotor laminations rotate, they will affect the magnetic flux density at the entry end and the magnetic flux density at the exit end of the permanent magnet. Therefore, by setting the groove sizes at both ends of the magnet slot to be different, the width of the permanent magnet pole facing the air gap can be adjusted, thereby reducing the magnetic leakage at both ends of the permanent magnet pole.

[0042] Meanwhile, the groove is positioned near the end of the permanent magnet, which limits magnetic leakage at the end of the permanent magnet and increases the output torque.

[0043] Preferably, the two ends of the magnet slot are an inlet end and an outlet end, respectively. The groove near the inlet end is a first groove, and the groove near the outlet end is a second groove. The width of the first groove along the circumferential direction of the rotor lamination is smaller than the width of the second groove along the circumferential direction of the rotor lamination.

[0044] In this scheme, the width of the first groove at the entry end is set to be smaller than the width of the second groove at the exit end. This can balance the magnetic flux density effect caused by the rotation of the rotor laminations, make the magnetic flux density of adjacent magnetic poles more uniform and symmetrical, avoid torque fluctuations caused by rapid changes in magnetic permeability, balance the rotor force, and reduce unilateral magnetic pull.

[0045] Preferably, the end face of the rotor lamination also has an arc-shaped weight-reducing hole extending along the circumferential direction of the rotor lamination. The arc-shaped weight-reducing hole is located inside the magnet slot and is provided in a one-to-one correspondence with the magnet slot. The central angle of the arc-shaped weight-reducing hole on the rotor lamination is the same as the central angle of the magnet slot on the rotor lamination.

[0046] In this design, the arc-shaped weight-reducing holes guide magnetic lines of force smoothly from the permanent magnet poles to the silicon steel poles, preventing localized magnetic saturation. These holes also reduce the weight of the rotor laminations, thereby lowering the overall weight and cost of the motor. Especially in high-power motors, reducing rotor inertia significantly improves the response speed and energy efficiency of the control system. Furthermore, the arc-shaped holes balance the weight of the rotor laminations, enhancing the motor's operational stability. Finally, the increased surface area of ​​the rotor laminations promotes heat transfer, improves the motor's heat dissipation performance, and ensures stable operation over extended periods.

[0047] By configuring the central angle of the arc-shaped weight-reducing hole on the rotor lamination to be the same as the central angle of the magnet slot on the rotor lamination, the transmission path of the magnetic field lines from the permanent magnet to the motor shaft at the center of the rotor lamination can be blocked, thus reducing magnetic leakage.

[0048] Preferably, the end face of the rotor lamination also has a spindle-shaped hole, which is disposed between adjacent arc-shaped weight-reducing holes. The spindle-shaped hole has a pointed end and a rounded end, with the pointed end facing the outer side of the rotor lamination and the rounded end facing the center of the rotor lamination. The spindle-shaped hole extends along the radial direction of the rotor lamination.

[0049] In this design, the spindle-shaped hole is used not only to reduce the weight of the rotor lamination, but also to block the path of magnetic lines of force from the area between adjacent arc-shaped weight-reducing holes to the drive shaft of the rotor lamination, thus preventing magnetic leakage.

[0050] By pointing the tip of the spindle-shaped hole toward the outside of the rotor lamination, the magnetic lines of force flow smoothly, the sinusoidality of the air gap magnetic field is increased, torque fluctuations are reduced, and vibration and noise are reduced.

[0051] By positioning the arc end of the spindle-shaped hole towards the center of the rotor lamination, the surface area of ​​the rotor lamination is increased, thereby improving heat dissipation efficiency.

[0052] A unipolar motor, the unipolar motor comprising the rotor laminations of a unipolar motor as described above.

[0053] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0054] The positive and progressive effects of this invention are as follows: the rotor lamination is used in a unipolar motor, and the magnetic slots are used to install permanent magnets. The permanent magnets installed in all the magnetic slots on the rotor lamination have the same polarity, so as to form alternating silicon steel poles and permanent magnet poles on the outer circumferential surface of the rotor lamination. By setting multiple arc-shaped magnetic circuit guide slots at both ends of the magnetic slots, and the width of the magnetic circuit guide slots gradually decreases along the direction of the center of the rotor lamination, the magnetic lines of force can be guided from the permanent magnet poles to the silicon steel poles, extending the transmission path of the magnetic lines of force, making the magnetic reluctance of the silicon steel poles and the permanent magnet poles match, increasing the saliency ratio, improving the magnetic reluctance torque, and compensating for the torque drop caused by the reduction in the amount of magnets. Furthermore, setting the magnetic circuit guide slots to be arc-shaped can improve the sinusoidal nature of the air gap magnetic field, reduce torque fluctuations, and thus reduce vibration noise. In addition, the multiple arc-shaped magnetic circuit guide slots also play a role in magnetic isolation, preventing the magnetic lines of force from being transmitted in a straight line from the permanent magnet poles to the motor shaft at the center of the rotor lamination, thus preventing leakage magnetic field and suppressing harmonic amplitude. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the rotor laminations of a unipolar motor according to an embodiment of the present invention.

[0056] Figure 2 This is a schematic diagram of a partial structure of the rotor laminations of a unipolar motor according to an embodiment of the present invention. Figure 1 .

[0057] Figure 3 This is a schematic diagram of a partial structure of the rotor laminations of a unipolar motor according to an embodiment of the present invention. Figure 2 .

[0058] Figure 4 This is a schematic diagram of a partial structure of the rotor laminations of a unipolar motor according to an embodiment of the present invention. Figure 3 .

[0059] Figure 5 This is a schematic diagram of a partial structure of the rotor laminations of a unipolar motor according to an embodiment of the present invention. Figure 4 .

[0060] Figure 6 This is a comparison chart of the harmonic amplitudes of the original scheme without optimization and the optimized scheme of this embodiment.

[0061] Figure 7 This is a comparison chart of the torque of the original solution without optimization and the optimized solution in this embodiment.

[0062] Explanation of reference numerals in the attached figures:

[0063] Magnet trough 1

[0064] Magnetic circuit guide slot 2

[0065] First end 21

[0066] Second end 22

[0067] First magnetic circuit guide groove 23

[0068] Second magnetic circuit guide groove 24

[0069] Third magnetic circuit guide slot 25

[0070] Axis of symmetry 3

[0071] Groove 4

[0072] First groove 41

[0073] Second groove 42

[0074] 5 arc-shaped weight reduction holes

[0075] Spindle-shaped hole 6

[0076] Permanent magnet pole 100

[0077] Silicon steel electrode 200 Detailed Implementation

[0078] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0079] like Figures 1-5As shown, this embodiment discloses a rotor lamination for a unipolar motor. The end face of the rotor lamination is provided with at least two magnetic steel slots 1 spaced apart circumferentially. Each magnetic steel slot 1 has multiple arc-shaped magnetic circuit guide slots 2 at both ends. The magnetic circuit guide slots 2 are located inside the magnetic steel slots 1 and are bent toward the magnetic steel slots 1. The multiple magnetic circuit guide slots 2 are spaced apart along the radial direction of the rotor lamination. Among the multiple magnetic circuit guide slots 2 located at one end of the magnetic steel slots 1, the cross-sectional width of the magnetic circuit guide slots 2 gradually decreases along the direction close to the center of the rotor lamination. This rotor lamination is used in a unipolar motor. The magnet slots 1 are used to mount permanent magnets. All permanent magnets mounted in the magnet slots 1 of the rotor lamination have the same polarity, forming alternating silicon steel poles 200 and permanent magnet poles 100 on the outer circumferential surface of the rotor lamination. The permanent magnet poles 100 correspond one-to-one with the magnet slots 1, and the silicon steel poles 200 are located between adjacent permanent magnet poles 100. Multiple arc-shaped magnetic circuit guide slots 2 are provided at both ends of the magnet slots 1, and the width of the magnetic circuit guide slots 2 gradually decreases along the center direction of the rotor lamination. This guides the magnetic lines of force from the permanent magnet poles 100. The magnetic field line is extended to the silicon steel pole 200, which makes the magnetic reluctance of the silicon steel pole 200 and the permanent magnet pole 100 matched, increases the saliency ratio, improves the magnetic reluctance torque, and compensates for the torque drop caused by the reduction in the amount of magnet. In addition, the magnetic circuit guide groove 2 is set to be arc-shaped, which can improve the sinusoidality of the air gap magnetic field and reduce torque fluctuation, thereby reducing vibration noise. Furthermore, multiple arc-shaped magnetic circuit guide grooves 2 also play a role in magnetic isolation, preventing the magnetic field line from being conducted in a straight line from the permanent magnet pole 100 to the motor shaft at the center of the rotor lamination, thus preventing leakage magnetic field. It can also suppress harmonic amplitude.

[0080] The number of rotor lamination magnet slots 1 can be set to two or more as needed. This embodiment takes five magnet slots 1 as an example to illustrate the rotor lamination.

[0081] like Figure 1 As shown, the magnetic circuit guide grooves 2 located at both ends of the magnet slot 1 are symmetrical with respect to the axis of symmetry 3 passing through the center of the rotor lamination, which improves the symmetry of the magnetic flux density distribution of adjacent silicon steel poles 200, makes the magnetic resistance characteristics of silicon steel poles 200 and permanent magnet poles 100 match, and improves uniformity.

[0082] like Figure 3As shown, the end of the magnetic circuit guide groove 2 closest to the magnet slot 1 is the first end 21, and the end of the magnetic circuit guide groove 2 closest to the outer edge of the rotor lamination is the second end 22. The width of the magnetic circuit guide groove 2 along the radial direction of the rotor lamination gradually decreases from the first end 21 to the second end 22. By gradually decreasing the width of the magnetic circuit guide groove 2 along the radial direction of the rotor lamination from the first end 21 to the second end 22, the width of the magnetic bridge formed between adjacent magnetic circuit guide grooves 2 also gradually decreases along its circumferential direction. That is, the width of the magnetic bridge gradually increases from the end closest to the magnet slot 1 to the end closest to the silicon steel pole 200, which balances the magnetic flux density distribution on the magnetic bridge and makes the magnetic flux density at each point close to about 1.7T, making full use of the properties of the magnetically conductive material.

[0083] like Figure 1 As shown, in this embodiment, there are three magnetic circuit guide slots 2. These three magnetic circuit guide slots 2, along the direction close to the center of the rotor laminations, are respectively the first magnetic circuit guide slot 23, the second magnetic circuit guide slot 24, and the third magnetic circuit guide slot 25. Two magnetic bridges are formed between the three magnetic circuit guide slots 2, facilitating the convergence of magnetic lines of force and allowing them to be conducted along these bridges. This increases the sinusoidal nature of the air gap magnetic field, improves the reluctance torque, compensates for the torque decrease caused by the reduced amount of magnets, and increases the saliency ratio. Simultaneously, the magnetic circuit guide slots 2 also prevent magnetic leakage. Furthermore, providing three magnetic circuit guide slots 2 can increase the motor torque by more than 5%.

[0084] In other alternative embodiments, the number of magnetic circuit guide slots can be set to two or more as needed by the user.

[0085] like Figure 3 As shown, the distance from one end of the first magnetic circuit guide groove 23 to the outer edge of the rotor lamination is H1, the distance from one end of the second magnetic circuit guide groove 24 to the outer edge of the rotor lamination is H2, and the distance from one end of the third magnetic circuit guide groove 25 to the outer edge of the rotor lamination is H3. Setting the distance H1 between one end of the first magnetic circuit guide groove 23 and the outer edge of the rotor lamination to be equal to the distance H2 between one end of the second magnetic circuit guide groove 24 and the outer edge of the rotor lamination ensures that the strength between the silicon steel pole 200 and the permanent magnet pole 100 meets the requirements, while also guiding the magnetic lines of force effectively. Setting the distance H3 between one end of the third magnetic circuit guide groove 25 and the outer edge of the rotor lamination to be greater than H1 or H2 ensures both the strength of the middle part of the silicon steel pole 200 and a good magnetic shielding effect.

[0086] like Figure 4 As shown, the distance between the other end of the first magnetic circuit guide groove 23 and the magnetic steel groove 1 is H5, the distance between the other end of the second magnetic circuit guide groove 24 and the magnetic steel groove 1 is H6, and the distance between one end of the third magnetic circuit guide groove 25 and the magnetic steel groove 1 is H7. The distance H5 between the other end of the first magnetic circuit guide groove 23 and the magnetic steel groove 1 is set to be less than H6 or H7. At the same time, the distance H6 between the other end of the second magnetic circuit guide groove 24 and the magnetic steel groove 1 is set to be equal to the distance H7 between one end of the third magnetic circuit guide groove 25 and the magnetic steel groove 1. This is mainly used to extend the transmission path of the magnetic lines of force and reduce inter-pole leakage and end-face leakage.

[0087] like Figure 3 and Figure 4 As shown, the distance from one end of the first magnetic circuit guide groove 23 to the outer edge of the rotor lamination is H1, with H1 ranging from 0.4 to 0.6 mm. The distance from the other end of the first magnetic circuit guide groove 23 to the magnet slot 1 is H5, with H5 ranging from 0.5 to 0.6 mm. The thicknesses of the rotor lamination at both ends of the first magnetic circuit guide groove 23 are H1 and H5, respectively. By setting H1 to a range of 0.4 to 0.6 mm and H5 to a range of 0.5 to 0.6 mm, it is ensured that the magnetic lines of force of the permanent magnet pole 100 reach the silicon steel pole 200 through H5 and H1, while also taking into account the magnetic isolation effect of the first magnetic circuit guide groove 23 to prevent magnetic leakage. Furthermore, it ensures that the rotor lamination has sufficient strength to prevent the problem of localized weakness caused by excessively large openings.

[0088] like Figure 3 and Figure 4 As shown, the distance from one end of the second magnetic circuit guide groove 24 to the outer edge of the rotor lamination is H2, and the value of H2 is equal to the value of H1. The distance from the other end of the second magnetic circuit guide groove 24 to the magnet slot 1 is H6, and the value of H6 ranges from 1.1 to 1.3 mm. The thicknesses of the rotor lamination at both ends of the second magnetic circuit guide groove 24 are H2 and H6, respectively. Setting the value of H2 to be equal to the value of H1, that is, the value range of H2 is 0.4 to 0.6 mm, and the value range of H6 is 1.1 to 1.3 mm, ensures that the magnetic lines of force of the permanent magnet pole 100 reach the silicon steel pole 200 through H6 and H2, while also taking into account the magnetic isolation effect of the second magnetic circuit guide groove 24 to prevent magnetic leakage, and also ensuring that the rotor lamination has sufficient strength to prevent the problem of local weakness caused by excessively large openings.

[0089] like Figure 3 and Figure 4As shown, the distance from one end of the third magnetic circuit guide groove 25 to the outer edge of the rotor lamination is H3, and the value of H3 ranges from (1.3~1.5)*H2. The distance from one end of the third magnetic circuit guide groove 25 to the magnet slot 1 is H7, and the value of H7 ranges from 1~1.2mm. The thicknesses of the rotor lamination at both ends of the third magnetic circuit guide groove 25 are H3 and H7, respectively. The value of H3 ranges from (1.3~1.5)*H2 mm, and the value of H7 ranges from 1~1.2mm. This ensures that the magnetic lines of force of the permanent magnet pole 100 reach the silicon steel pole 200 through H3 and H7, while also taking into account the magnetic isolation effect of the third magnetic circuit guide groove 25 to prevent magnetic leakage. It also ensures that the rotor lamination has sufficient strength and prevents the problem of local weakness caused by excessively large openings.

[0090] like Figure 2 As shown, the third magnetic circuit guide groove 25 includes a first arc segment and a second arc segment that are not concentrically arranged. The first arc segment and the second arc segment enclose the third magnetic circuit guide groove 25. The radius of the first arc segment ranges from [value missing]. mm, of which, P represents the number of magnet slots 1. Let be the radius of the rotor lamination, and the range of values ​​for the radius of the second arc segment be... mm. The third magnetic circuit guide groove 25 includes a first arc segment and a second arc segment that are not concentrically arranged, which facilitates the formation of a third magnetic circuit guide groove 25 with a gradually changing width. The radius of the first arc segment is set to a range of values. mm, the range of values ​​for the radius of the second arc segment is set to mm, so that the shape and size of the third magnetic circuit guide slot 25 are related to the radius of the rotor lamination. In relation to the number P of the magnet slots 1, by adjusting the radius of the rotor laminations and the number of magnet slots 1, the radius of the corresponding first arc segment can be obtained, so that users can design third magnetic circuit guide slots 25 of different sizes.

[0091] like Figure 1 and Figure 2 As shown, the second magnetic circuit guide groove 24 includes a third arc segment and a fourth arc segment that are not concentrically arranged. The third arc segment and the fourth arc segment enclose the second magnetic circuit guide groove 24. The radius of the third arc segment is within a certain range. mm, the radius of the fourth arc segment has a range of values ​​of . mm, of which, P represents the number of magnet slots 1, and Z represents the number of stator teeth that mate with the rotor laminations. The second magnetic circuit guide slot 24 includes a third and fourth arc segments that are not concentrically arranged, facilitating the formation of a second magnetic circuit guide slot 24 with a gradually changing width. The radius of the third arc segment is set to a range of values. mm, the range of values ​​for the radius of the fourth arc segment is set to mm, so that the shape and size of the second magnetic circuit guide groove 24 are associated with the third magnetic circuit guide groove 25, and when the parameters of the third magnetic circuit guide groove 25 are adjusted, the parameters of the second magnetic circuit guide groove 24 are adjusted accordingly. The greatest common divisor of 2P and Z is... It is the least common multiple of 2P and Z. For example, for a 10-slot, 12-pole motor, P=5, Z=12, then The greatest common divisor is 2. The least common multiple is 60.

[0092] like Figure 1 and Figure 2 As shown, the first magnetic circuit guide groove 23 includes a fifth arc segment and a sixth arc segment that are not concentrically arranged. The fifth arc segment and the sixth arc segment enclose the first magnetic circuit guide groove 23. The radius of the fifth arc segment ranges from [value missing]. mm, the radius of the sixth arc segment has a range of values ​​of . mm, of which, P represents the number of magnet slots 1, and Z represents the number of stator teeth that cooperate with the rotor laminations. The first magnetic circuit guide slot 23 includes a fifth arc segment and a sixth arc segment that are not concentrically arranged, which facilitates the formation of a first magnetic circuit guide slot 23 with a gradually changing width. The radius of the fifth arc segment is set to a range of values. mm, the range of values ​​for the radius of the sixth arc segment is set to mm, so that the shape and size of the second magnetic circuit guide groove 24 are associated with the third magnetic circuit guide groove 25 through the second magnetic circuit guide groove 24. When the parameters of the third magnetic circuit guide groove 25 are adjusted, the parameters of the second magnetic circuit guide groove 24 and the first magnetic circuit guide groove 23 are adjusted accordingly. It is the least common multiple of 2P and Z. It is the greatest common divisor of 2P and Z.

[0093] like Figure 5 As shown, a preset area A is provided on the end face of the rotor lamination, and preset areas A are also provided at both ends of the magnet slot 1. Preset area A is enclosed by the outer boundary of the rotor lamination, the extension line of the sixth arc segment, and the extension line of the end face of the magnet slot 1. Multiple magnetic isolation holes B are provided within the preset area. The ratio of the sum of the areas of the multiple magnetic isolation holes B to the area of ​​the preset area A is in the range of 0.2 to 0.5, which can reduce magnetic leakage at the end of the magnet slot 1 and increase the magnetic reluctance torque. The number, location, and shape of the magnetic isolation holes can be set according to user needs, but must meet the above ratio range to prevent magnetic leakage while ensuring the strength requirements of the preset area.

[0094] like Figure 2As shown, the magnetic circuit guide groove 2 is arc-shaped, located at one end of the magnet groove 1. The centers of all the magnetic circuit guide grooves 2 are located within a preset circular area, and the angle between the line connecting the center of the circular area and the center of the rotor lamination and the axis of symmetry 3 is . Where P is the number of magnetic steel grooves 1. The arc-shaped magnetic circuit guide groove 2 ensures that the width of the magnetic circuit guide groove 2 gradually changes along its own circumferential direction. Correspondingly, a magnetic bridge is obtained between adjacent magnetic circuit guide grooves 2, which facilitates the conduction and convergence of magnetic lines of force. The magnetic lines of force are conducted along the magnetic bridge, and the propagation path is blocked at the position of the magnetic circuit guide groove 2, which increases the sinusoidality of the air gap magnetic field, increases the reluctance torque, compensates for the torque decrease caused by the reduction of the amount of magnets, increases the saliency ratio, and at the same time, the magnetic circuit guide groove 2 can also avoid magnetic leakage.

[0095] like Figure 2 As shown, the diameter d of the preset central region can be set according to user needs. Preferably, the diameter d of the preset central region is no greater than 1mm. The magnetic circuit guide groove 2 is arc-shaped, and the center of the magnetic circuit guide groove 2 is located on the outer side of the rotor lamination, which can obtain a larger arc segment, and thus obtain a larger magnetic circuit guide groove 2.

[0096] In an alternative approach, the center of the magnetic circuit guide groove is located inside the rotor lamination, which allows for a smaller arc segment and thus a smaller magnetic circuit guide groove.

[0097] In an alternative scheme, the magnetic circuit guide groove is a groove formed by two partial segments of an ellipse, which can also guide the magnetic lines of force to the silicon steel pole in a preset direction.

[0098] like Figure 1 As shown, the outer circumferential surface of the rotor lamination has grooves 4, and each magnet slot 1 has grooves 4 at both ends, with the grooves 4 at the two ends of the magnet slot 1 having different sizes. In a unipolar motor, one permanent magnet is installed on one adjacent magnetic pole and the other is not. Because the permanent magnet has a constraining effect on the magnetic lines of force, the magnetic flux density distribution of adjacent magnetic poles is asymmetrical. By setting grooves 4 of different sizes at both ends of the magnet slot 1, the magnetic flux density distribution of the permanent magnet poles 100 can be balanced, making the magnetic flux density of adjacent magnetic poles more symmetrical. By weakening the position of each harmonic peak, the odd and even harmonics in the air gap magnetic flux density are reduced, thereby reducing the back EMF harmonic content and reducing torque ripple. Furthermore, since the rotor laminations have a rotational direction, the permanent magnet has an entry end and an exit end. Due to the influence of armature reaction and changes in magnetic permeability, the rotation of the rotor laminations affects the magnetic flux density at both the entry and exit ends of the permanent magnet. Therefore, by setting the sizes of the grooves 4 at both ends of the magnet slot 1 to be different, the width of the permanent magnet pole 100 facing the air gap can be adjusted, thereby reducing magnetic leakage at both ends of the permanent magnet pole 100. Simultaneously, the grooves 4 are positioned near the ends of the permanent magnet, limiting magnetic leakage at the ends and increasing the output torque.

[0099] like Figure 1 As shown, in this embodiment, the rotor laminations rotate counterclockwise. The two ends of the magnetic slot 1 are the entry end and the exit end, respectively. The groove 4 near the entry end is the first groove 41, and the groove 4 near the exit end is the second groove 42. The width of the first groove 41 along the circumferential direction of the rotor lamination is smaller than the width of the second groove 42 along the circumferential direction of the rotor lamination. Setting the width of the first groove 41 at the entry end to be smaller than the width of the second groove 42 at the exit end can balance the magnetic flux density effect caused by the rotation of the rotor laminations, making the magnetic flux density of adjacent magnetic poles more uniform and symmetrical, avoiding torque fluctuations caused by rapid changes in magnetic permeability, balancing the rotor force, and reducing unilateral magnetic pull.

[0100] like Figure 1 As shown, the end face of the rotor lamination also has an arc-shaped weight-reducing hole 5 extending along the circumferential direction of the rotor lamination. The arc-shaped weight-reducing hole 5 is located inside the magnet slot 1 and is set one-to-one with the magnet slot 1. The central angle of the arc-shaped weight-reducing hole 5 on the rotor lamination is the same as the central angle of the magnet slot 1 on the rotor lamination. By configuring the central angle of the arc-shaped weight-reducing hole 5 on the rotor lamination to be the same as the central angle of the magnet slot 1 on the rotor lamination, the transmission path of the magnetic field lines from the permanent magnet to the motor shaft at the center of the rotor lamination can be blocked, reducing magnetic leakage. The arc-shaped weight-reducing hole 5 can guide the magnetic field lines to be smoothly transmitted from the permanent magnet pole 100 to the silicon steel pole 200, avoiding local magnetic saturation. The arc-shaped weight-reducing hole 5 can also reduce the weight of the rotor lamination, thereby reducing the overall weight and cost of the motor. Especially in high-power motors, reducing rotor inertia can significantly improve the response speed and energy efficiency of the control system. The arc-shaped weight-reducing hole 5 can also balance the weight of the rotor lamination, enhancing the operating stability of the motor. The arc-shaped weight-reducing hole 5 also increases the surface area of ​​the rotor laminations, promotes heat transfer, enhances the heat dissipation performance of the motor, and ensures stable operation of the motor for a long time.

[0101] like Figure 1 As shown, the end face of the rotor lamination also has a spindle-shaped hole 6, which is disposed between adjacent arc-shaped weight-reducing holes 5. The spindle-shaped hole 6 has a pointed end and a rounded end, with the pointed end facing the outer side of the rotor lamination and the rounded end facing the center of the rotor lamination. The spindle-shaped hole 6 extends along the radial direction of the rotor lamination. The spindle-shaped hole 6 serves both to reduce the weight of the rotor lamination and to block the path of magnetic lines of force from the area between adjacent arc-shaped weight-reducing holes 5 to the drive shaft of the rotor lamination, thus preventing magnetic leakage.

[0102] By pointing the tip of the spindle-shaped hole 6 towards the outer side of the rotor lamination, the magnetic field lines flow smoothly, increasing the sinusoidal nature of the air gap magnetic field and reducing torque fluctuations, thereby reducing vibration and noise. Setting the arc end of the spindle-shaped hole 6 towards the center of the rotor lamination increases the surface area of ​​the rotor lamination and improves heat dissipation efficiency.

[0103] exist Figure 6 and Figure 7 The image shows a comparison of the software simulation effects of the original, unoptimized solution and the optimized solution of this embodiment. The unoptimized solution is the one without the arc-shaped magnetic circuit guide groove, while the optimized solution is the one in this embodiment that includes multiple arc-shaped magnetic circuit guide grooves. Compared to the original, unoptimized solution, from... Figure 6 As we can see, the amplitudes of the third, fifth, and seventh harmonics in the optimized scheme of this embodiment are significantly reduced, thereby greatly reducing vibration noise. Figure 7 As we can see, the torque of the optimized solution in this embodiment has also been greatly improved. Figure 7 The electromagnetic scheme in this context refers to the application of rotor laminations to the motor.

[0104] This embodiment also discloses a unipolar motor, which includes the rotor laminations of the unipolar motor as described above.

[0105] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A rotor lamination of a single-phase electric machine, characterized in that The end surface of the rotor lamination is provided with at least two magnetic steel grooves in a circumferential direction, each of the magnetic steel grooves is provided with a plurality of arc-shaped magnetic path guide grooves at two ends thereof, the magnetic path guide grooves are located at the inner side of the magnetic steel groove, the magnetic path guide grooves are curved towards the direction of the magnetic steel groove, a plurality of the magnetic path guide grooves are arranged in the radial direction of the rotor lamination, and the cross-sectional width of the magnetic path guide grooves gradually decreases in the direction close to the center of the rotor lamination.

2. A rotor lamination for a single-phase electric machine according to claim 1, characterized in that, The magnetic path guide grooves at the two ends of the magnetic steel groove are symmetrical relative to the axis of symmetry passing through the center of the rotor lamination.

3. A rotor lamination for a single-phase electric machine according to claim 2, characterized in that, The magnetic path guide groove close to one end of the magnetic steel groove is a first end, and the magnetic path guide groove close to one end of the outer edge of the rotor lamination is a second end, and the width of the magnetic path guide groove in the radial direction of the rotor lamination gradually decreases from the first end to the second end.

4. A rotor lamination for a single-phase electric machine according to claim 3, characterized in that, The number of the magnetic path guide grooves is three, and the three magnetic path guide grooves are respectively a first magnetic path guide groove, a second magnetic path guide groove and a third magnetic path guide groove in the direction close to the center of the rotor lamination.

5. A rotor lamination for a single-phase electric machine according to claim 4, characterized in that, A distance from an outer edge of the rotor lamination to one end of the first magnetic circuit guide slot is H1, a distance from the outer edge of the rotor lamination to one end of the second magnetic circuit guide slot is H2, and a distance from the outer edge of the rotor lamination to one end of the third magnetic circuit guide slot is H3, ; And / or, the other end of the first magnetic circuit guide groove is H5 away from the magnetic steel groove, the other end of the second magnetic circuit guide groove is H6 away from the magnetic steel groove, and one end of the third magnetic circuit guide groove is H7 away from the magnetic steel groove, .

6. A rotor lamination for a single-phase electric machine according to claim 5, characterized in that, The distance from one end of the first magnetic path guide groove to the outer edge of the rotor lamination is H1, and the value of H1 is in the range of 0.4-0.6 mm, and the distance from the other end of the first magnetic path guide groove to the magnetic steel groove is H5, and the value of H5 is in the range of 0.5-0.6 mm. And / or, the distance from one end of the second magnetic path guide groove to the outer edge of the rotor lamination is H2, and the value of H2 is equal to the value of H1, and the distance from the other end of the second magnetic path guide groove to the magnetic steel groove is H6, and the value of H6 is in the range of 1.1-1.3 mm. And / or, the distance from one end of the third magnetic path guide groove to the outer edge of the rotor lamination is H3, and the value of H3 is in the range of (1.3-1.5)*H2, and the distance from one end of the third magnetic path guide groove to the magnetic steel groove is H7, and the value of H7 is in the range of 1-1.2 mm.

7. A rotor lamination for a single-phase electric machine according to claim 6, characterized in that, The third magnetic circuit guide groove comprises a first circular arc segment and a second circular arc segment arranged concentrically, the first circular arc segment and the second circular arc segment enclose the third magnetic circuit guide groove, the radius of the first circular arc segment ranges from 5 mm to 15 mm, mm, wherein, P is the number of magnetic steel grooves, is the radius of the rotor lamination, and the radius of the second circular arc segment ranges from 5 mm to 15 mm, mm. And / or, the second magnetic circuit guide groove comprises a third circular arc segment and a fourth circular arc segment arranged concentrically, the third circular arc segment and the fourth circular arc segment enclose the second magnetic circuit guide groove, the radius of the third circular arc segment ranges from 0.5 mm to 1.5 mm, and the radius of the fourth circular arc segment ranges from 0.5 mm to 1.5 mm. mm, the radius of the fourth circular arc segment ranges from 0.5 mm to 1.5 mm. mm, wherein, P is the number of magnetic steel grooves, Z is the number of teeth of a stator used in cooperation with the rotor punching piece, wherein, is the greatest common divisor of 2P and Z, is the least common multiple of 2P and Z. And / or, the first magnetic circuit guide groove comprises a fifth circular arc segment and a sixth circular arc segment arranged concentrically, the fifth circular arc segment and the sixth circular arc segment enclose the first magnetic circuit guide groove, the radius of the fifth circular arc segment ranges from 0.5 mm to 1.5 mm, and the radius of the sixth circular arc segment ranges from 0.5 mm to 1.5 mm. mm, the radius of the sixth circular arc segment ranges from 0.5 mm to 1.5 mm. mm, wherein, P is the number of magnetic steel grooves, Z is the number of teeth of the stator used in cooperation with the rotor punching piece, wherein, is the greatest common divisor of 2P and Z, is the least common multiple of 2P and Z.

8. A rotor lamination for a single-phase electric machine according to claim 7, characterized in that, The end surface of the rotor lamination is provided with a preset area, and the two ends of the magnetic steel groove are provided with the preset area, the preset area is surrounded by the outer boundary of the rotor lamination, the extension line of the sixth arc segment and the end surface extension line of the magnetic steel groove, and a plurality of magnetic isolation holes are arranged in the preset area, and the area ratio of the plurality of magnetic isolation holes to the area of the preset area is in the range of 0.2-0.

5.

9. A rotor lamination for a single-phase electric machine as claimed in claim 2, characterized in that, The magnetic circuit guide grooves are circular arc-shaped, and the centers of all the magnetic circuit guide grooves at one end of the magnetic steel groove are located in a preset circular region, and the angle between the line connecting the center of the circular region and the center of the rotor lamination and the symmetry axis is wherein P is the number of the magnetic steel grooves; And / or, the magnetic path guide groove is in the shape of a circular arc, and the center of the circular arc is located at the outer side of the rotor lamination.

10. A rotor lamination for a single-phase electric machine according to any one of claims 1-9, characterized in that, The outer circumferential surface of the rotor lamination has a groove, and the two ends of each magnetic steel groove are provided with the groove, and the sizes of the grooves at the two ends of the magnetic steel groove are different.

11. A rotor lamination for a single-phase electric machine according to claim 10, characterized in that, The two ends of the magnetic steel groove are respectively an entry end and an exit end, the groove close to the entry end is a first groove, the groove close to the exit end is a second groove, and the width of the first groove in the circumferential direction of the rotor lamination is smaller than the width of the second groove in the circumferential direction of the rotor lamination.

12. A rotor lamination for a single-phase electric machine according to any one of claims 1-9, characterized in that, The end surface of the rotor lamination further has arc-shaped lightening holes extending in the circumferential direction of the rotor lamination, the arc-shaped lightening holes being located inside the magnetic steel grooves and arranged one-to-one in correspondence with the magnetic steel grooves, and the corresponding central angle of the arc-shaped lightening holes on the rotor lamination being the same as the corresponding central angle of the magnetic steel grooves on the rotor lamination.

13. A rotor lamination for a single-phase electric machine according to claim 12, characterized in that, The end surface of the rotor lamination further has spindle-shaped holes arranged between adjacent arc-shaped lightening holes, the spindle-shaped holes having a pointed end and a circular arc end, the pointed end facing the outside of the rotor lamination, and the circular arc end facing the center of the rotor lamination, the spindle-shaped holes being arranged to extend in the radial direction of the rotor lamination.

14. A single polarity electric machine characterized by, The single-pole electric machine comprises the rotor lamination of the single-pole electric machine according to any one of claims 1-13.

Images