Unipolar motor based on magnetic pole modulation and harmonic slot collaborative optimization

Abstract

The invention discloses a unipolar motor based on magnetic pole modulation and harmonic slot collaborative optimization, which comprises a unipolar rotor punching sheet, the peripheral surface of the unipolar rotor punching sheet is provided with alternate first magnetic poles and second magnetic poles, the polarities of the first magnetic poles and the second magnetic poles are opposite, the periphery of the first magnetic poles is provided with a first arc, and the periphery of the second magnetic poles is provided with a second arc. The periphery of the first magnetic pole is provided with a first arc, the periphery of the second magnetic pole is provided with a second arc, the first arc and the second arc are concentrically arranged relative to the center of the unipolar rotor punching sheet, and the radius of the first magnetic pole is greater than that of the second magnetic pole, so that the air gap magnetic resistance is increased and the motor efficiency is ensured under the condition that the effective area of the air gap magnetic flux is not obviously changed; the amplitude of each order harmonic electromagnetic radial force caused by a rotor magnetic field is reduced, and the purpose of reducing the vibration noise of the motor is achieved. The motor has wide application prospects in the fields of new energy automobiles, aerospace, numerical control machine tools and the like, and the comfort and high-end quality of products can be effectively improved.

Description

Technical Field

[0001] The invention relates to a unipolar motor based on coordinated optimization of magnetic pole modulation and harmonic slots. Background Art

[0002] With the continued advancement of the dual-carbon strategy, the development of high-efficiency, energy-saving motors has become an urgent need for industrial transformation and upgrading. To adapt to the development of key areas such as new energy vehicles and high-end manufacturing, motors must meet higher requirements for high efficiency, low noise, and low cost. To improve the utilization rate of rare earth materials, existing technologies have developed unipolar motors that can significantly reduce the use of rare earth materials. However, compared with traditional NS alternating-pole permanent magnet motors, unipolar motors face severe inherent challenges in vibration and noise control. The root cause lies in the integer spatial harmonics caused by the asymmetric magnetic circuit structure.

[0003] Traditional NS alternating-pole motors (with 2P permanent magnets) have a symmetrical airgap magnetic field and a highly sinusoidal magnetic flux waveform. The primary electromagnetic force wave components are concentrated in low-order components (such as 2nd and 4th order). While these low-order force waves have large amplitudes, their excitation frequencies are relatively low and can be effectively predicted and suppressed through sophisticated slot-pole matching and stator and rotor tooth profile optimization techniques. However, unipolar motors (with P permanent magnets) employ a topology that alternates permanent magnet (N) poles with silicon steel poles (pseudo-S) poles. The inherent differences in magnetic permeability and magnetomotive force between permanent magnet poles and silicon steel poles severely distort the airgap magnetic flux waveform, generating abundant odd-order and other integer-order spatial harmonics, leading to a surge in harmonic content. Furthermore, the interaction of these harmonics with the armature magnetic field excites electromagnetic radial force waves. Due to the prevalence of harmonics and radial force waves, unipolar motors generally exhibit significantly higher vibration and noise levels than NS alternating-pole motors. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a unipolar motor based on the coordinated optimization of magnetic pole modulation and harmonic slots.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] A unipolar motor based on coordinated optimization of magnetic pole modulation and harmonic slots includes a unipolar rotor punching, wherein the unipolar rotor punching has a first magnetic pole and a second magnetic pole alternately arranged in the circumferential direction, the polarity of the first magnetic pole and the second magnetic pole are opposite, the outer periphery of the first magnetic pole has a first circular arc, the outer periphery of the second magnetic pole has a second circular arc, the first circular arc and the second circular arc are concentrically arranged relative to the center of the unipolar rotor punching, and the radius of the first magnetic pole is greater than the radius of the second magnetic pole.

[0007] In the present scheme, compared with the ordinary N-S pole permanent magnet alternating pole motor, only a single polarity permanent magnet is arranged on the single polarity rotor lamination, and the permanent magnets are arranged at intervals on the single polarity rotor lamination. The permanent magnets magnetize the part of the iron core without permanent magnets into a virtual pole with opposite polarity, that is, the first magnetic pole and the second magnetic pole arranged alternately can be formed in the circumferential direction of the rotor lamination, and the magnetism of the second magnetic pole is opposite to that of the first magnetic pole. Therefore, the number of permanent magnets used by the single polarity rotor lamination is half of that of the ordinary N-S alternating pole motor, which can greatly save the number of permanent magnets and improve economic benefits. The outer circumferential arc of the first magnetic pole and the outer circumferential arc of the second magnetic pole are concentrically arranged with the center of the rotor lamination, and the radius of the first magnetic pole is greater than that of the second magnetic pole. Compared with the prior art scheme in which the eccentric radii are not equal, resulting in a decrease in effective air gap magnetic flux and a decrease in average magnetic flux density, the present scheme can increase the air gap reluctance while ensuring that the effective area of the air gap magnetic flux does not change significantly, thereby ensuring the efficiency of the motor; and it does not introduce additional harmonics, which reduces the amplitude of the electromagnetic radial force of each order of harmonic caused by the rotor magnetic field while ensuring the uniformity of the air gap magnetic flux per pole of the motor, thereby achieving the purpose of reducing the vibration and noise of the motor.

[0008] Preferably, a first harmonic slot is arranged on the first magnetic pole, and the distance between the bottom of the first harmonic slot and the center of the single polarity rotor lamination is greater than or equal to 0.9 times the radius of the second magnetic pole. This can not only reduce the magnetic leakage coefficient of the motor, increase the main magnetic flux amplitude of the motor, and improve the efficiency of the motor, but also optimize the direction of the magnetic force line and improve the torque.

[0009] Preferably, the second magnetic pole has a second harmonic slot, and the number of the second harmonic slots is two, which are arranged at intervals along the circumferential direction of the single polarity rotor lamination.

[0010] In the present scheme, the second harmonic slot arranged on the second magnetic pole can suppress the harmonic amplitude generated at the position of the second magnetic pole. Preferably, the number of the second harmonic slots is two, which are arranged at intervals along the circumferential direction of the single polarity rotor lamination. This can finely modulate the magnetic field and further reduce the amplitude of the harmonic generated at the position of the second magnetic pole, thereby reducing the torque fluctuation and achieving the purpose of reducing noise.

[0011] The two harmonic slots can also optimize the direction of the magnetic force line on the first magnetic pole, reduce the magnetic leakage coefficient of the motor, increase the main magnetic flux amplitude of the motor, and improve the efficiency of the motor.

[0012] Preferably, the distance between the two second harmonic slots along the circumferential direction of the single polarity rotor lamination is a first distance, and the corresponding central angle of the first distance in the single polarity rotor lamination is equal to the corresponding central angle of the first harmonic slot in the single polarity rotor lamination.

[0013] In this solution, the two second harmonic slots are associated with the first harmonic slot so that the three slots can work together to reduce the amplitude of the harmonics generated by the first magnetic pole position and the second magnetic pole position, thereby achieving the purpose of reducing torque fluctuations and reducing the vibration noise of the motor.

[0014] Preferably, the radius of the first magnetic pole is The radius of the second magnetic pole The relationship is: .

[0015] In this solution, optimizing the second magnetic pole range can significantly reduce the problem of magnetic flux amplitude asymmetry and reduce motor torque fluctuation.

[0016] Preferably, the central angle of the first harmonic slot corresponding to the circumferential direction of the unipolar rotor punching is The value range is ,in, is the central angle of the first magnetic pole in the unipolar rotor punching, The value of , P is the number of first magnetic poles.

[0017] In this solution, the above-mentioned structural arrangement can reduce the amplitude of the electromagnetic radial force, thereby reducing the vibration noise of the motor, guiding the direction of the magnetic circuit, and reducing the secondary magnetic flux.

[0018] Preferably, the end face of the unipolar rotor punching has at least two magnetic steel slots, and at least two of the magnetic steel slots are spaced apart along the circumferential direction of the unipolar rotor punching, and the magnetic steel slots correspond to the first magnetic pole. The magnetic steel slot includes a permanent magnet segment located in the middle and magnetic isolation segments located at both ends of the magnetic steel slot. The two magnetic isolation segments are symmetrical relative to the permanent magnet segment, and the permanent magnet segment is used to install permanent magnets. The magnetic isolation segment extends along the axial direction of the unipolar rotor punching to form a first magnetic isolation hole.

[0019] In this solution, the magnetic isolation section is used to optimize the direction of the magnetic lines of force at both ends of the permanent magnet, and also to extend the conduction path of the magnetic lines of force to avoid local magnetic line saturation. The first magnetic isolation hole can also be used to dissipate heat from the rotor punchings.

[0020] Preferably, a second magnetic isolation hole is provided at both ends of each second magnetic pole, the second magnetic isolation hole is arranged close to the first magnetic isolation hole, the second magnetic isolation hole and the adjacent first magnetic isolation hole form a magnetic isolation bridge, the magnetic isolation bridge extends along the radial direction of the unipolar rotor punching, there is an inter-pole center line between the first magnetic pole and the adjacent second magnetic pole, and the first magnetic isolation hole and the second magnetic isolation hole are symmetrically arranged relative to the inter-pole center line.

[0021] In the scheme, the second magnetic isolation hole is used for optimizing the magnetic flux direction of the second magnetic pole position and for dissipating heat of the rotor lamination. The magnetic isolation bridge forms a conduction path of the magnetic flux, so that the magnetic flux is conducted along the extension direction of the magnetic isolation bridge to prevent magnetic leakage. The magnetic isolation bridge can greatly reduce the leakage coefficient of the motor, and the strength of the magnetic isolation bridge meets the rotating stress requirement of the rotor.

[0022] Preferably, a third harmonic groove is arranged on the outer circumferential surface of the single-polarity rotor lamination, and the third harmonic groove is arranged on the joint of the first magnetic pole and the second magnetic pole, and the third harmonic groove is symmetrical relative to the inter-pole center line.

[0023] In the scheme, the above structure is used to optimize the pole arc coefficient of the rotor, thereby reducing the leakage coefficient and torque fluctuation of the motor.

[0024] Preferably, the third harmonic groove forms an isosceles trapezoidal groove structure with an outer large and inner small structure, the isosceles trapezoidal groove structure includes a short bottom and a long bottom, the short bottom corresponds to a central angle in the single-polarity rotor lamination, and the value of the central angle is in the range of , and the long bottom corresponds to a central angle in the single-polarity rotor lamination, and the value of the central angle is in the range of , wherein is a central angle of the first magnetic pole in the single-polarity rotor lamination, and P is the number of the first magnetic poles.

[0025] In the scheme, the above structure is used to optimize the pole arc coefficient of the rotor, thereby reducing the leakage coefficient and torque fluctuation of the motor.

[0026] Preferably, the first magnetic isolation hole, the second magnetic isolation hole, and the magnetic isolation bridge occupy a central angle in the circumferential direction of the single-polarity rotor lamination, and the value of the central angle is in the range of .

[0027] In the scheme, the above structure is used to optimize the magnetic flux direction of the joint of the first magnetic pole and the second magnetic pole, prevent local magnetic density saturation, prevent inter-pole magnetic leakage, increase the main magnetic flux amplitude of the motor, and improve the efficiency of the motor.

[0028] Preferably, the thickness of the magnetic isolation bridge in the circumferential direction of the single-polarity rotor lamination is , and the value of the thickness is in the range of 0.4mm ≤0.5mm.

[0029] In the scheme, the above structure is used to meet the rotating stress requirement of the rotor and greatly reduce the leakage coefficient of the motor.

[0030] Preferably, an inner side of the joint of the first magnetic pole and the second magnetic pole is provided with a third magnetic isolation hole, which is symmetrical relative to the inter-pole center line.

[0031] In the present solution, the above structure is adopted to reduce the self-coupling coefficient of the first magnetic pole, increase the air gap magnetic flux density amplitude of the motor, and thus improve the power and efficiency of the motor.

[0032] Preferably, the third magnetic isolation hole is a pentagonal magnetic isolation hole, a tip of the pentagonal magnetic isolation hole is directed to the joint of the first magnetic isolation hole and the second magnetic isolation hole, and the first magnetic isolation hole, the second magnetic isolation hole, the third harmonic slot and the third magnetic isolation hole form a H-shaped structure.

[0033] The central angle of the pentagonal magnetic isolation hole in the circumferential direction of the single-polarity rotor lamination is . ,

[0034] The distance between the midpoint of the bottom side of the pentagonal magnetic isolation hole and the center of the single-polarity rotor lamination is . , wherein R is the radius of the first magnetic pole.

[0035] In the present solution, the first magnetic isolation hole, the second magnetic isolation hole, the third harmonic slot and the third magnetic isolation hole jointly form a H-shaped structure, the H-shaped structure forms a magnetic flux conduction path, the magnetic flux is conducted along the direction of the H-shaped structure, local magnetic flux saturation is avoided, and magnetic flux leakage is also prevented. The pentagonal magnetic isolation hole is symmetrical relative to the inter-pole center line at the tip position, the tip of the pentagonal magnetic isolation hole is directed to the outside, the magnetic flux is smoothly conducted along the two sides of the tip, and magnetic flux leakage is prevented.

[0036] On the basis of common general knowledge in the art, the above-mentioned preferred conditions can be combined arbitrarily, i.e., to obtain each preferred embodiment of the present application.

[0037] The positive progress effect of the application is that: when the permanent magnet is installed in each magnetic steel slot of the rotor lamination, the rotor lamination is magnetized by the permanent magnet, then the first magnetic pole and the second magnetic pole are formed in the circumferential direction of the rotor lamination, and the area between the adjacent second magnetic poles is magnetized by the permanent magnet as the first magnetic pole opposite to the second magnetic pole in magnetism. Although the polarity of all the permanent magnets is the same, the rotor lamination can also form the NS alternating poles by the way of magnetizing the rotor lamination by the permanent magnet, compared with the alternating pole motor, the number of permanent magnets can be greatly saved, and the economic benefit is improved. The radius of the first magnetic pole is configured to be greater than the radius of the second magnetic pole, so as to ensure the uniformity of the air gap magnetic flux of each pole of the motor, and also can reduce the amplitude of each order harmonic electromagnetic radial force caused by the rotor magnetic field, so as to meet the design requirements of different motors, and also achieve the purpose of reducing the vibration and noise of the motor. The first harmonic slot is arranged on the first magnetic pole, and the distance between the bottom of the first harmonic slot and the center of the single-pole rotor lamination is greater than or equal to 0.9 times the radius of the second magnetic pole, which can not only reduce the magnetic leakage coefficient of the motor, increase the main magnetic flux amplitude of the motor, and improve the efficiency of the motor, but also can optimize the direction of the magnetic force line and improve the torque. The plurality of magnetic isolation holes can guide the direction of the magnetic force line, avoid local magnetic saturation, and prevent magnetic leakage. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 Structure diagram of the single-pole rotor lamination of the motor of a preferred embodiment of the application Figure 1 .

[0039] Figure 2 Structure diagram of the single-pole rotor lamination of the motor of a preferred embodiment of the application Figure 2 .

[0040] Figure 3 Comparison diagram of the torque of the un-slotted optimized rotor lamination and the slotted optimized rotor lamination of the motor of a preferred embodiment of the application.

[0041] Figure 4 Comparison diagram of the electromagnetic radial force circumferential distribution amplitude of the un-slotted optimized rotor lamination and the slotted optimized rotor lamination of the motor of a preferred embodiment of the application.

[0042] Figure 5 NVH simulation diagram of the un-slotted optimized rotor lamination of the motor of a preferred embodiment of the application.

[0043] Figure 6 NVH simulation diagram of the slotted optimized rotor lamination of the motor of a preferred embodiment of the application.

[0044] Explanation of reference signs:

[0045] Magnetic steel slot 1

[0046] Permanent magnet segment 11

[0047] Magnetic isolation section 12

[0048] First magnetic pole 2

[0049] First harmonic slot 21

[0050] Second magnetic pole 3

[0051] Second harmonic slot 31

[0052] The first magnetic isolation hole 4

[0053] Second magnetic isolation hole 5

[0054] Magnetic isolation bridge 6

[0055] Third Harmonic Slot 7

[0056] The third magnetic isolation hole 8

[0057] Unipolar rotor punching 100

[0058] Interpolar centerline 200 DETAILED DESCRIPTION

[0059] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0060] like Figures 1-4 As shown, this embodiment discloses a unipolar motor based on coordinated optimization of magnetic pole modulation and harmonic slots. The motor comprises a unipolar rotor sheet 100. The end surface of the unipolar rotor sheet 100 has at least two magnetic steel slots 1 (five magnetic steel slots 1 are shown in the figure). The at least two magnetic steel slots 1 are spaced apart along the circumference of the unipolar rotor sheet 100 to form alternating first magnetic poles 2 and second magnetic poles 3 on the outer circumference of the unipolar rotor sheet 100. When a permanent magnet is installed in each magnetic steel slot 1 of the rotor sheet, the adjacent magnetic poles are magnetized by the permanent magnet, forming alternating first magnetic poles 2 and second magnetic poles 3 along the circumference of the rotor sheet. The polarity of the first magnetic pole 2 is opposite to that of the second magnetic pole 3. Even though all the permanent magnets have the same polarity, the rotor sheet can still form alternating N-S poles by magnetizing the rotor sheet with permanent magnets. Compared with conventional alternating-pole motors, this significantly reduces the number of permanent magnets and improves economic efficiency. The outer arc of the first magnetic pole 2 and the outer arc of the second magnetic pole 3 are concentric with the center of the rotor punching, and the radius R of the first magnetic pole 2 is set to pm Greater than the radius R of the second magnetic pole 3 feCompared with the prior art, the eccentric radius is not equal, the effective air gap magnetic flux is reduced, and the average magnetic density is reduced. The setting can increase the air gap reluctance and ensure the motor efficiency without obvious change of the effective area of the air gap magnetic flux. The setting does not introduce additional harmonics, reduces the amplitude of the electromagnetic radial force of each order caused by the rotor magnetic field, and achieves the purpose of reducing the vibration and noise of the motor.

[0061] In the embodiment, the first magnetic pole 2 is a permanent magnet pole provided with a permanent magnet, and the second magnetic pole 3 is a silicon steel pole. In another embodiment, when the silicon steel pole is the first magnetic pole 2, the permanent magnet pole is the second magnetic pole 3.

[0062] As shown in Figure 1 In the embodiment, the first magnetic pole 2 has a first harmonic slot 21, and the distance from the bottom of the first harmonic slot 21 to the center of the single-pole rotor lamination 100 is greater than or equal to 0.9 times the radius of the second magnetic pole 3 and less than the radius of the single-pole rotor lamination. The radius of the single-pole rotor lamination is the nominal radius of the single-pole rotor lamination, that is, the theoretical design value of the radius of the single-pole rotor lamination, also known as the initial value. In the embodiment, the nominal radius of the single-pole rotor lamination 100 is the radius of the virtual circle on which the outer circumferential arc of the first magnetic pole 2 is located. If the difference between the distance from the bottom of the first harmonic slot 21 to the center of the single-pole rotor lamination and the radius of the second magnetic pole 3 is too large, it will seriously affect the operating efficiency of the single-pole motor. By opening the slot on the first magnetic pole 2 and optimizing the relationship between the first harmonic slot 21 and the radius of the second magnetic pole 3, the motor leakage coefficient can be reduced, the motor main flux amplitude can be increased, the motor efficiency can be improved, the magnetic flux path can be optimized, and the torque can be improved.

[0063] Preferably, the bottom surface of the first harmonic slot 21 is a circular arc surface, which can disperse stress, avoid local stress peak, weaken stress concentration during motor operation, and improve the mechanical fatigue life of the rotor.

[0064] As shown in Figure 1As shown, in this embodiment, the second magnetic pole 3 has a second harmonic slot 31, and the number of the second harmonic slots 31 is two. The two second harmonic slots 31 are spaced apart along the circumferential direction of the unipolar rotor punching 100. Providing the second harmonic slots 31 on the second magnetic pole 3 can suppress the amplitude of the harmonics generated at the position of the second magnetic pole 3. Preferably, the number of the second harmonic slots 31 is set to two, and the two harmonic slots are spaced apart along the circumferential direction of the unipolar rotor punching 100, which is equivalent to modulating the magnetic field twice, effectively suppressing spatial harmonics of a specific order, further reducing the amplitude of the harmonics generated at the position of the second magnetic pole 3, and the resulting torque fluctuation is relatively small, the motor runs more smoothly, and the purpose of reducing noise is achieved. The two harmonic slots can also optimize the direction of the magnetic lines of force on the second magnetic pole 3, reduce the motor leakage coefficient, increase the amplitude of the motor main magnetic flux, and improve the motor efficiency.

[0065] Preferably, the number of second harmonic slots may be three or more.

[0066] like Figure 2 As shown, in this embodiment, the spacing between the two second harmonic slots 31 along the circumferential direction of the unipolar rotor punching 100 is a first spacing, and the first spacing corresponds to a central angle of the unipolar rotor punching 100. The first harmonic slot 21 has a central angle equal to that of the first harmonic slot 21 in the unipolar rotor lamination 100. The slot opening of the first harmonic slot 21 is wider than that of the second harmonic slot 31. The larger slot opening can adjust the air gap magnetic field waveform, while the smaller slot opening can significantly reduce the cogging torque. By associating the two second harmonic slots with the first harmonic slot 21, the three slots work together to precisely and efficiently reduce the amplitude of the harmonics generated at the positions of the first magnetic pole 2 and the second magnetic pole 3, thereby reducing torque fluctuations and, in turn, the vibration and noise of the motor.

[0067] The central angle corresponding to the first spacing in the unipolar rotor punching 100 The value range is ,in, is the central angle of the first magnetic pole 2 in the unipolar rotor punching 100, The value of , P is the number of the first magnetic poles 2. Each second harmonic slot 31 is a semicircular slot, and the first spacing is the distance between the centers of two second harmonic slots. Preferably, the radius of the second harmonic slot 31 is The value range is mm.

[0068] In this embodiment, the radius of the first magnetic pole 2 The radius of the second magnetic pole 3 The relationship is: , the radius difference is too large, the average torque is sacrificed, and the motor efficiency is reduced, and the motor efficiency is reduced Under the premise of ensuring the performance of the motor, the electromagnetic radial force amplitude of each order harmonic caused by the rotor magnetic field can be reduced, thereby reducing the motor vibration noise.

[0069] In the embodiment, the central angle of the first harmonic slot 21 corresponding to the circumferential direction of the single-pole rotor lamination 100 is The value of the central angle of the first magnetic pole 2 in the single-pole rotor lamination 100 is , wherein is the central angle of the first magnetic pole 2 in the single-pole rotor lamination 100, The value of the central angle of the first magnetic pole 2 in the single-pole rotor lamination 100 is , P is the number of first magnetic poles 2. A too narrow slot width cannot form a large enough magnetic resistance barrier, and part of the magnetic flux will pass through the core of the slot edge to form a bypass, increasing the risk of magnetic leakage. A too wide slot width will destroy the continuity of the magnetic field, which may exacerbate the air gap permeance variation and the cogging torque. A suitable harmonic slot can make the air gap magnetic field distribution tend to be sinusoidal, reduce the electromagnetic radial force amplitude, reduce the vibration and noise of the motor, and guide the magnetic circuit to the rotor. Reduce the secondary magnetic flux.

[0070] In another embodiment, i.e., the silicon steel pole is the first magnetic pole 2, and the permanent magnet pole is the second magnetic pole 3, the first harmonic slot 21 is located on the silicon steel pole, and the second harmonic slot 31 is located on the permanent magnet pole. This type of rotor can also weaken the motor vibration and reduce the vibration noise.

[0071] As shown in Figure 1 and Figure 2 , in the embodiment, the magnetic steel slot 1 includes a permanent magnet segment 11 located in the middle and a magnetic segment 12 located at both ends of the magnetic steel slot 1. The two magnetic segments 12 are symmetrical with respect to the permanent magnet segment 11. The permanent magnet segment 11 is used to install the permanent magnet. When the permanent magnet segment 11 is installed with the permanent magnet, the magnetic segment 12 extends along the axial direction of the single-pole rotor lamination 100 to form a first magnetic gap 4. The magnetic segment 12 is used to optimize the direction of the magnetic force line at both ends of the permanent magnet, and also prolongs the conduction path of the magnetic force line, avoiding local magnetic force line saturation. The first magnetic gap 4 can also be used for heat dissipation of the rotor lamination.

[0072] As shown in Figure 1 and Figure 2As shown, in the embodiment, each second magnetic pole 3 is provided with a second magnetic isolation hole 5 at both ends, the second magnetic isolation hole 5 is arranged close to the first magnetic isolation hole 4, the second magnetic isolation hole 5 and the adjacent first magnetic isolation hole 4 form a magnetic isolation bridge 6, the magnetic isolation bridge 6 is arranged along the radial direction of the single-pole rotor lamination 100, the first magnetic pole 2 and the adjacent second magnetic pole 3 have an inter-pole center line 200, and the first magnetic isolation hole 4 and the second magnetic isolation hole 5 are symmetrically arranged relative to the inter-pole center line 200. The second magnetic isolation hole 5 is used to optimize the magnetic flux direction of the position of the second magnetic pole 3, and also can be used for heat dissipation of the rotor lamination. The magnetic isolation bridge 6 forms a conduction path of the magnetic flux, so that the magnetic flux is conducted along the extension direction of the magnetic isolation bridge 6, and the inter-pole leakage magnetic is prevented. The magnetic isolation bridge 6 can greatly reduce the leakage coefficient of the motor, and the strength of the magnetic isolation bridge 6 meets the rotating stress requirement of the rotor.

[0073] In the embodiment, the thickness of the magnetic isolation bridge 6 along the circumferential direction of the single-pole rotor lamination 100 is , and the value range of is 0.4mm ≤0.5mm. The thickness of the magnetic isolation bridge 6 meets the rotating stress requirement of the rotor, and can greatly reduce the leakage coefficient of the motor.

[0074] Preferably, the distance between the two adjacent second magnetic isolation holes 5 is equal to the length of the permanent magnet segment 11, so as to balance the magnetic force.

[0075] In the embodiment, the third harmonic groove 7 is arranged on the outer circumferential surface of the single-pole rotor lamination 100, and the third harmonic groove 7 is arranged on the combined part of the first magnetic pole 2 and the second magnetic pole 3, and the third harmonic groove 7 is symmetrically arranged relative to the inter-pole center line 200. The third harmonic groove 7 arranged above can optimize the pole arc coefficient of the rotor, thereby reducing the leakage coefficient and torque fluctuation of the motor.

[0076] Figure 2 As shown, in the embodiment, the third harmonic groove 7 forms an isosceles trapezoidal groove structure with large outer and small inner, the isosceles trapezoidal groove structure includes a short bottom and a long bottom, the short bottom corresponds to a central angle in the single-pole rotor lamination 100, and the value range of , and the long bottom corresponds to a central angle in the single-pole rotor lamination 100, and the value range of . The above structure is used to optimize the pole arc coefficient of the rotor, thereby reducing the leakage coefficient and torque fluctuation of the motor.

[0077] In the embodiment, the first magnetic isolation hole 4, the second magnetic isolation hole 5 and the magnetic isolation bridge 6 occupy a central angle in the circumferential direction of the single-pole rotor lamination 100, and the value range of , the magnetic flux line direction of the combined position of the first magnetic pole 2 and the second magnetic pole 3 is optimized, local magnetic density saturation is prevented, inter-pole magnetic leakage is prevented, the main magnetic flux amplitude of the motor is increased, and the motor efficiency is improved.

[0078] In the embodiment, the inner side of the combined part of the first magnetic pole 2 and the second magnetic pole 3 is provided with a third magnetic isolation hole 8, which is symmetrical with respect to the inter-pole center line 200, for reducing the self-coupling coefficient of the second magnetic pole, increasing the air gap magnetic density amplitude of the motor, and thus improving the motor power and efficiency.

[0079] In the embodiment, the third magnetic isolation hole 8 is a pentagonal magnetic isolation hole, the tip of the pentagonal magnetic isolation hole is directed to the combined part of the first magnetic isolation hole 4 and the second magnetic isolation hole 5, and the first magnetic isolation hole 4, the second magnetic isolation hole 5, the third harmonic slot 7, and the third magnetic isolation hole 8 jointly form a H-shaped structure. The central angle of the pentagonal magnetic isolation hole in the circumferential direction of the single-pole rotor lamination 100 is , the value range of the distance between the midpoint of the bottom side of the pentagonal magnetic isolation hole and the center of the single-pole rotor lamination 100 is , and the value range of the distance between the midpoint of the bottom side of the pentagonal magnetic isolation hole and the center of the single-pole rotor lamination 100 is , where R is the radius of the first magnetic pole 2. The first magnetic isolation hole 4, the second magnetic isolation hole 5, the third harmonic slot 7, and the third magnetic isolation hole 8 jointly form a H-shaped structure, the H-shaped structure forms a magnetic flux conduction path, the magnetic flux is conducted along the direction of the H-shaped structure, local magnetic density saturation is avoided, and inter-pole magnetic leakage is prevented. The tip of the pentagonal magnetic isolation hole is symmetrical with respect to the inter-pole center line 200, the tip of the pentagonal magnetic isolation hole is directed to the outside, the magnetic flux is smoothly conducted along the two sides of the tip, and inter-pole magnetic leakage is prevented. Preferably, the midpoints of the bottom sides of all the pentagonal magnetic isolation holes are on a circle with a radius of R.

[0080] In the embodiment, the single-pole rotor lamination 100 has a shaft hole for mounting a transmission shaft in the middle part.

[0081] The torque of the un-slotted optimized rotor lamination and the slotted optimized rotor lamination is simulated, and the simulation results are shown in Figure 3 . The torque fluctuation is reduced from 8% to 2%, and the average torque is increased from 3 Nm to 3.05 Nm. In this paper, the slotted optimized rotor lamination is the rotor lamination of the present application.

[0082] Further, the electromagnetic radial force circumferential distribution amplitude of the un-slotted optimized rotor lamination and the slotted optimized rotor lamination is simulated, and the simulation results are shown in Figure 4 ​As shown, the optimized magnetic radial force is significantly reduced, and the motor vibration noise performance is improved. Further, NVH (Noise, Vibration, Harshness) simulation of the rotor lamination is performed. The NVH simulation result of the un-slotted optimized rotor lamination is as shown in Figure 5 The NVH simulation result of the slotted optimized rotor lamination is as shown in Figure 6 From the data in Figure 5 and Figure 6 It can be seen that the maximum sound pressure level before optimization is 78dB, and the maximum sound pressure level after optimization is 33.4dB, and the motor noise vibration performance is obviously improved.

[0083] The application can be applied to the field of intelligent electrical appliances to reduce the working noise of intelligent electrical appliances, to protect the hearing health of residents, and to create a good living environment. Taking an intelligent fume exhaust machine equipped with the motor of the application as an example, users can realize intelligent control of the motor through voice control. Since the motor of the application has excellent performance and effectively reduces noise, it can improve the user experience and create a beautiful smart kitchen. With excellent noise reduction performance, the motor of the application also has broad application prospects in the fields of new energy vehicles, aerospace, numerical control machine tools, etc., and can effectively improve the comfort and high-end quality of products.

[0084] Although the specific embodiments of the application are described above, those skilled in the art should understand that this is only an example, and the protection scope of the application 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 application, and such changes and modifications fall within the protection scope of the application.

Claims

1. A single polarity motor based on pole modulation and harmonic slot coordination optimization, characterized in that, The single-pole rotor lamination includes first and second magnetic poles alternately arranged in the circumferential direction, the first and second magnetic poles having opposite polarities, the outer periphery of the first magnetic pole having a first circular arc, the outer periphery of the second magnetic pole having a second circular arc, the first and second circular arcs being concentrically arranged with respect to the center of the single-pole rotor lamination, and the radius of the first magnetic pole being greater than the radius of the second magnetic pole.

2. The single polarity machine based on pole modulation and harmonic slot coordination optimization of claim 1, wherein, The first magnetic pole is provided with a first harmonic slot, and the distance from the bottom of the first harmonic slot to the center of the single-pole rotor lamination is greater than or equal to 0.9 times the radius of the second magnetic pole.

3. The single polarity machine based on pole modulation and harmonic slot coordination optimization of claim 2, wherein, The second magnetic pole is provided with a second harmonic slot, and the number of the second harmonic slot is two, and the two second harmonic slots are arranged at intervals in the circumferential direction of the single-pole rotor lamination.

4. The single polarity machine based on pole modulation and harmonic slot coordination optimization of claim 3, wherein, The interval of the two second harmonic slots in the circumferential direction of the single-pole rotor lamination is a first interval, and the corresponding central angle of the first harmonic slot in the single-pole rotor lamination is equal to the corresponding central angle of the first harmonic slot in the single-pole rotor lamination.

5. The single polarity machine based on pole modulation and harmonic slot coordination optimization of claim 1, wherein, a radius of the first magnetic pole a radius of the second magnetic pole .​ 6. The single polarity machine based on pole modulation and harmonic slot coordination optimization of claim 2, wherein, The central angle corresponding to the width of the first harmonic slot along the circumferential direction of the unipolar rotor punching is The value range is ,in, is the central angle of the first magnetic pole in the unipolar rotor punching, The value of , P is the number of first magnetic poles.

7. The single polarity machine based on pole modulation and harmonic slot coordination optimization of claim 1, wherein, The end surface of the single-pole rotor lamination has at least two magnetic steel grooves arranged at intervals in the circumferential direction of the single-pole rotor lamination, the magnetic steel grooves correspond to the first magnetic poles, the magnetic steel grooves include a permanent magnet segment in the middle and a magnetic shielding segment at both ends of the magnetic steel groove, the two magnetic shielding segments are symmetrical with respect to the permanent magnet segment, the permanent magnet segment is used to install a permanent magnet, and the magnetic shielding segment extends in the axial direction of the single-pole rotor lamination to form a first magnetic shielding hole.

8. The single polarity machine based on pole modulation and harmonic slot coordination optimization of claim 7, wherein, Each of the second magnetic poles is provided with a second magnetic shielding hole at both ends, the second magnetic shielding hole is arranged close to the first magnetic shielding hole, the second magnetic shielding hole and the adjacent first magnetic shielding hole form a magnetic shielding bridge, the magnetic shielding bridge extends in the radial direction of the single-pole rotor lamination, the first magnetic pole and the adjacent second magnetic pole have an inter-pole center line, and the first magnetic shielding hole and the second magnetic shielding hole are symmetrically arranged with respect to the inter-pole center line.

9. The single polarity machine based on pole modulation and harmonic slot coordination optimization of claim 8, wherein, The outer periphery of the single-pole rotor lamination is provided with a third harmonic slot, the combination part of the first magnetic pole and the second magnetic pole is provided with the third harmonic slot, and the third harmonic slot is symmetrical with respect to the inter-pole center line.

10. The single polarity machine based on pole modulation and harmonic slot coordination optimization of claim 9, wherein, The third harmonic slot forms an isosceles trapezoidal slot structure with an outer large and inner small, the isosceles trapezoidal slot structure includes a short bottom and a long bottom, the short bottom corresponds to a central angle of the single-pole rotor lamination The value range of The long bottom corresponds to a central angle of the single-pole rotor lamination The value range of , wherein The central angle of the first magnetic pole in the single-pole rotor lamination, The value of P is the number of first magnetic poles.

11. The single polarity machine based on pole modulation and harmonic slot cooperation optimization of claim 10, wherein, The first magnetic isolation hole, the second magnetic isolation hole and the magnetic isolation bridge occupy a central angle in the circumferential direction of the single-polarity rotor lamination The value range of the central angle is .

12. The single polarity machine based on pole modulation and harmonic slot coordination optimization of claim 8, wherein, a thickness of the magnetic isolation bridge in a circumferential direction of the unipolar rotor lamination is in the range of 0.4 mm < d < 0.5 mm. is in the range of 0.4 mm < d < 0.5 mm.

13. The single polarity machine based on pole modulation and harmonic slot coordination optimization of claim 10, wherein, The inner side of the combination part of the first magnetic pole and the second magnetic pole is provided with a third magnetic shielding hole, and the third magnetic shielding hole is symmetrical with respect to the inter-pole center line.

14. The single polarity machine based on pole modulation and harmonic slot cooperation optimization of claim 13, wherein, The third magnetic shielding hole is a pentagonal magnetic shielding hole, the tip of the pentagonal magnetic shielding hole faces the combination part of the first magnetic shielding hole and the second magnetic shielding hole, and a I-shaped structure is formed between the first magnetic shielding hole, the second magnetic shielding hole, the third harmonic slot and the third magnetic shielding hole. The central angle of the five-edge magnetic isolation hole in the circumferential direction of the single-polarity rotor lamination The value range of the central angle of the five-edge magnetic isolation hole in the circumferential direction of the single-polarity rotor lamination is The value range of the central angle of the five-edge magnetic isolation hole in the circumferential direction of the single-polarity rotor lamination is the distance between the midpoint of the bottom side of the five-sided magnetic isolation hole and the center of the single-polarity rotor lamination the value range of the radius of the first magnetic pole is wherein, the radius of the first magnetic pole.

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