Rotor punching sheet
By designing V-shaped magnet slots, pole spacing magnetic bridges, and through-hole structures on the rotor laminations, the high-frequency noise problem in household air conditioner compressors has been solved, achieving a balance between motor efficiency and noise, and optimizing electromagnetic force density.
Patent Information
- Application Number
- CN202423006868.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-05
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2034-12-05
AI Technical Summary
Existing household air conditioner compressors have relatively high noise levels in the mid-to-high frequency range (1200-2000HZ). The electromagnetic noise is related to the motor structure mode, and there is a lack of effective technical solutions to balance the radial electromagnetic force density at low, medium and high frequencies.
Design a rotor lamination with V-shaped magnet slots in the circumference and pole spacing magnetic bridges in between. The rotor lamination has through holes near the centroid to reduce the second-order spatial electromagnetic force density, and the outer edge cut optimizes the magnetic field line orientation to reduce the eccentricity effect.
While maintaining the same motor efficiency, the noise in the mid-to-high frequency range was significantly reduced, the second-order spatial electromagnetic force density was optimized, and the noise spike of the compressor was lowered.
Smart Images
Figure CN223613118U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to motor technical field, concretely relates to a rotor punching sheet. BACKGROUND
[0002] Now mainstream household air conditioner compressor on the market has medium high frequency band (1200-2000HZ) noise point. The electromagnetic noise of motor is directly related to its electromagnetic force and motor structure mode, because the operation range of variable frequency motor is wider, the influence of electromagnetic noise is throughout low medium high frequency band, and the electromagnetic force density of different frequency bands of motor is difficult to all design at lower value. The industry lacks a simple and effective technical solution to solve the above problems. SUMMARY
[0003] The utility model discloses a rotor punching sheet, under the premise of guaranteeing motor efficiency as far as possible, balance radial electromagnetic force density under low medium high frequency, weaken full frequency band radial 2 order electromagnetic force density, reduce compressor 1200-2000HZ nearby noise.
[0004] To realize above-mentioned purpose, the utility model provides a rotor punching sheet, the circumference of rotor punching sheet is equipped with a plurality of V type magnet slot, the opening of V of V type magnet slot forms and faces outward, any two V type rotor magnet slot has pole interval magnetic bridge, the through hole is set up on rotor punching sheet, the through hole is close to pole interval magnetic bridge setting, the through hole is closer to the centroid of rotor punching sheet relative to pole interval magnetic bridge, and the through hole is used for reducing second order space electromagnetic force density of rotor punching sheet.
[0005] Optionally, the pole interval magnetic bridge and the V type magnet slot are arranged at an angle to form a first corner point, and a minimum distance between an edge of the through hole and the first corner point is greater than or equal to 0.45 cm and less than or equal to 0.8 cm.
[0006] Optionally, a minimum distance between an edge of the through hole and an edge of the pole interval magnetic bridge is greater than or equal to 0.45 cm and less than or equal to 0.8 cm.
[0007] Optionally, the through hole is circular, and the through hole is further used for inserting a fastener.
[0008] Optionally, the rotor punching sheet further includes a first auxiliary slot, the first auxiliary slot is further away from the centroid of the rotor punching sheet relative to the V type magnet slot, the first auxiliary slot is located within the opening range of the V of the V type magnet slot, an outer edge cutout is provided on an outer edge of the rotor punching sheet, and the outer edge cutout is provided between two adjacent first auxiliary slots within the opening range of the V of the V type magnet slot.
[0009] Optionally, the outer edge cutout is arranged between the first auxiliary slot and the pole axis of the rotor lamination.
[0010] Optionally, the rotor lamination further comprises a second auxiliary slot, the second auxiliary slot is farther away from the centroid of the rotor lamination relative to the V-shaped magnet slot, the second auxiliary slot is located within the opening range of the V of the V-shaped magnet slot, and the outer edge cutout is arranged between the first auxiliary slot and the second auxiliary slot.
[0011] Optionally, the outer edge cutout has a second corner point, and the second corner point is located on the axis of the first auxiliary slot.
[0012] Optionally, the outer edge cutout has a first end point and a second end point at two ends of the opening, a first connecting line is formed between the first end point and the centroid of the rotor lamination, a second connecting line is formed between the second corner point and the centroid of the rotor lamination, a third connecting line is formed between the second end point and the centroid of the rotor lamination, a first angle is formed between the first connecting line and the pole axis, a second angle is formed between the second connecting line and the pole axis, and a third angle is formed between the third connecting line and the pole axis, and the absolute value of the difference between the first angle and the second angle is greater than or equal to 0.5 degrees, and the absolute value of the difference between the second angle and the third angle is greater than or equal to 0.5 degrees.
[0013] Optionally, the outer edge cutout has a first end point and a second end point at two ends of the opening, a first connecting line is formed between the first end point and the centroid of the rotor lamination, a second connecting line is formed between the second corner point and the centroid of the rotor lamination, a third connecting line is formed between the second end point and the centroid of the rotor lamination, a first angle is formed between the first connecting line and the pole axis, a second angle is formed between the second connecting line and the pole axis, and a third angle is formed between the third connecting line and the pole axis, and the distance between the second corner point and the first end point is less than the distance between the second corner point and the second end point, the first end point is farther away from the pole axis within the opening range of the V of the V-shaped magnet slot relative to the second end point, the angle between the axis of the first auxiliary slot and the side of the V-shaped magnet slot intersecting the axis is θ, the first angle is θ1, the second angle is θ2, and the third angle is θ3, and θ1-θ2=2.7-(θ-90) and θ2-θ3=2.7+(θ-90) are satisfied, and if the calculation result of 2.7-(θ-90) or 2.7+(θ-90) is negative, the calculation result is directly taken as 0.5.
[0014] The rotor lamination provided by the utility model has the following beneficial effects:
[0015] The utility model provides a rotor punching piece, be equipped with several V type magnet grooves in the rotor punching piece circumference, the opening of V of V type magnet groove forms outward, the opening both sides outside of V of V type magnet groove is equipped with pole interval magnetic bridge, the rotor punching piece is equipped with through -hole, the through -hole is closer to the centroid of the rotor punching piece relative to the pole interval magnetic bridge, the distance between the through -hole edge and the pole interval magnetic bridge is in the first preset range, the through -hole is used for reducing the second order space electromagnetic force density of the rotor punching piece. The utility model discloses a person researches to find that the mainstream household air conditioner compressor has the noise point of medium high frequency band (1200-2000HZ), this is mainly because the structure of household air conditioner compressor determines that it has the second order mode in medium high frequency band (1200-2000HZ), and this mode is easily excited by the space second order electromagnetic force of motor due to rotor installation eccentricity to cause the abnormal noise peak of compressor in medium high frequency band. The utility model discloses a through -hole is designed to greatly optimize the second order space electromagnetic force under the condition that the no -load performance of motor is unchanged and other order space electromagnetic force density does not increase greatly, and then weaken the noise peak of compressor in medium high frequency (1200-2000HZ), can be used as low noise motor rotor punching piece for air conditioner compressor. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 The rotor punching piece is provided for an embodiment of the utility model.
[0017] Figure 2 The position relation schematic drawing of the through -hole of the rotor punching piece and V type magnet groove and pole interval magnetic bridge is provided for an embodiment of the utility model.
[0018] Figure 3 The comparative schematic drawing of the second order space radial electromagnetic force density under different frequencies without using the utility model and the second order radial electromagnetic force density under different frequencies using the utility model.
[0019] Figure 4 The position schematic drawing of the outer edge cut -out on the outer edge of the rotor punching piece is provided for an embodiment of the utility model.
[0020] Figure 5 The position relation schematic drawing between the outer edge cut -out and the first auxiliary groove, V type magnet groove and magnetic pole axis is provided for an embodiment of the utility model.
[0021] Figure 6 The comparative schematic drawing of motor no -load power potential waveform change after the through -hole 13 and the outer edge cut -out 21 of an embodiment of the utility model are opened.
[0022] Figure 7 The comparative schematic drawing of output torque change under the same current after the through -hole 13 and the outer edge cut -out 21 of an embodiment of the utility model are opened.
[0023] Wherein the reference signs are:
[0024] 11 - V-shaped magnet slot; 110 - first corner point; 12 - inter-pole gap magnetic bridge; 13 - through hole; 14 - first auxiliary slot; 140 - axis of the first auxiliary slot; 15 - shaft hole; 16 - oil hole; 17 - rivet hole;
[0025] 20 - pole axis; 21 - outer edge notch; 22 - second auxiliary slot; 211 - first end point; 210 - second corner point; 212 - second end point;
[0026] 101 - first connecting line; 102 - second connecting line; 103 - third connecting line. DETAILED DESCRIPTION
[0027] In order to make the purpose, advantages and characteristics of the utility model more clear, the following will make further detailed description to the utility model combining with the drawings and specific embodiments. It should be noted that the drawings are all very simplified form and are not drawn according to proportion, only to facilitate, clearly assist the purpose of explaining the embodiment of the utility model. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing needs to be different, sometimes different proportions are used.
[0028] It will be understood that when an element or layer is referred to as being "on" or "connected to" another element or layer, it can be directly on or connected to the other element or layer or intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element or layer, there are no intervening elements or layers present. Although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these terms are not intended to denote a particular order or hierarchy. These terms are used only to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application. Spatially relative terms such as "beneath", "below", "lower", "above", "upper", and the like can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if a device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. The terms of degree such as "substantially", "approximately", and the like, are used herein to describe applicable embodiments. When the term "substantially" is used in reference to a given property, characteristic, parameter or other metric, it is acting as a mere qualification that it is "a majority" or "a substantial number" or "a substantial amount", but not "all" or "100%" of the given property, characteristic, parameter or other metric. As such, the term "substantially" is not acting to qualify or otherwise change the meaning of the given property, characteristic, parameter or other metric. The term "comprises" is used herein to mean that it includes the stated features, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.
[0029] The utility model discloses a rotor punching sheet, under the premise of guaranteeing motor efficiency as far as possible, balance low middle high frequency radial electromagnetic force density, weaken middle high frequency noise, reduce compressor noise.
[0030] Please refer to Figure 1 , Figure 1 The overall schematic diagram of the rotor punching sheet provided by the embodiment of the utility model is shown in the figure. Figure 1To achieve the above object, the utility model provides a rotor lamination, a plurality of V type magnet grooves 11 are equipped in the circumference of rotor lamination, the opening of V of V type magnet groove 11 forms outward, any two V type rotor magnet grooves 11 have pole interval magnetic bridge 12, that is, the both sides of the opening of V of V type magnet groove 11 have pole interval magnetic bridge 12, the through hole 13 is set up on the rotor lamination, the through hole 13 is closer to the centroid of rotor lamination relative to pole interval magnetic bridge 12, the through hole 13 is set up close to pole interval magnetic bridge 12, that is, the distance between the edge of through hole 13 and pole interval magnetic bridge 12 is in the first preset range, and the through hole 13 is used for reducing the second order spatial electromagnetic force density of rotor lamination. According to conventional setting, it should also include shaft hole 15, oil hole 16, rivet hole 17 and the like, which will not be repeated here.
[0031] The utility model person researches and finds that the mainstream household air conditioner compressor has the noise point of medium high frequency band (1200-2000HZ), which is mainly because the structure of household air conditioner compressor determines that it has the second order mode in medium high frequency band (1200-2000HZ), and the mode is easily excited by the spatial second order electromagnetic force caused by the eccentricity of rotor installation of motor, so that the compressor has abnormal noise convex point in medium high frequency band. By such setting, the utility model designs the through hole to greatly optimize the second order spatial electromagnetic force under the condition that the no-load and load performance of motor is unchanged and other order spatial electromagnetic force density is not greatly increased, and then weaken the noise convex point of compressor in medium high frequency (1200-2000HZ), which can be used as low noise motor rotor lamination for air conditioner compressor.
[0032] It should be noted that the through hole should be as close as possible to the V type magnet groove 11 and the pole interval magnetic bridge 12 under the premise of ensuring the strength of the rotor lamination to realize the reduction of the second order spatial electromagnetic force density of the rotor lamination, and at the same time, not to cause the body strength to decrease and damage due to being too close to the V type magnet groove 11 and the pole interval magnetic bridge 12, and the size of the first preset range should be determined according to this principle. For details, please refer to Figure 2 , Figure 2 The utility model an embodiment provides the position relation schematic drawing of the through hole 13 of rotor lamination and V type magnet groove 11 and pole interval magnetic bridge 12. As Figure 2As shown, the pole spacing magnetic bridge 12 and the V-shaped magnetic slot 11 can be arranged at an angle to form a first corner point 110, and the first corner point 110 can be used as a reference for the position of the through hole 13. In an exemplary embodiment, the minimum distance between the edge of the through hole 13 and the first corner point 110 is greater than or equal to 0.45 cm and less than or equal to 0.8 cm, but is not limited thereto. Another position reference for the through hole 13 can be the pole spacing magnetic bridge 12, and the minimum distance between the edge of the through hole 13 and the edge of the pole spacing magnetic bridge 12 is greater than or equal to 0.45 cm and less than or equal to 0.8 cm, but is not limited thereto. In Figure 2 In the embodiment shown, the through hole 13 is square, and the position of the through hole 13 can be further simplified by considering the position relationship between the square and the V-shaped magnetic slot 11 and the pole spacing magnetic bridge 12, and the position of the through hole 13 is determined based on the centroid of the through hole 13. Figure 2 The size of L1 and L2 determines the position of the through hole 13, and further determines the size of the through hole 13 itself. In an exemplary embodiment, the through hole 13 is square, and the side length L3 can be between 1.2 cm and 2 cm, but is not limited thereto.
[0033] Further, the through hole 13 can be circular, and the through hole 13 can also be used for inserting a fastener, thereby serving as a connection for the fastener and further reinforcing the rotor lamination, achieving one hole with multiple functions. It should be noted that the shape of the through hole 13 can also be other shapes, such as Figure 1 Figure 2 square, which will not be described again here.
[0034] Please refer to Figure 3 , Figure 3 is a comparison diagram of the second-order spatial radial electromagnetic force density at different frequencies without using the utility model and the second-order radial electromagnetic force density at different frequencies using the utility model. By Figure 3 We can find that the spatial second-order radial electromagnetic force density at different frequencies is greatly reduced after using the utility model, and the specific comparison data can be referred to the following two tables. Table 1 is the spatial radial electromagnetic force density at different frequencies without using the utility model, and Table 2 is the radial electromagnetic force density at different frequencies using the utility model.
[0035]
[0036] Table 1
[0037]
[0038] Table 2
[0039] Further, please refer to Figure 4 ,Figure 4 The rotor punching sheet further comprises a first auxiliary slot 14, the first auxiliary slot 14 is farther away from the centroid of the rotor punching sheet relative to the V-shaped magnet slot 11, the first auxiliary slot 14 is located in the opening range of the V-shaped magnet slot 11, the outer edge cutout 21 is arranged on the outer edge of the rotor punching sheet, and the outer edge cutout 21 is arranged between the two first auxiliary slots 14 adjacent to each other in the opening range of the V-shaped magnet slot 11. By means of the arrangement, the motor eccentric radial electromagnetic force density can be further reduced, and the motor noise can be further reduced. It should be understood that the first auxiliary slot 14 is generally axisymmetric about the magnetic pole axis 20 in the opening range of the V-shaped magnet slot, and then the outer edge cutout 21 should also be axisymmetric about the magnetic pole axis 20 in the opening range of the V-shaped magnet slot. The outer edge cutout 21 should be arranged between the first auxiliary slot 14 and the magnetic pole axis 20 of the rotor punching sheet.
[0040] Further, the rotor punching sheet further comprises a second auxiliary slot 22, the second auxiliary slot 22 is farther away from the centroid of the rotor punching sheet relative to the V-shaped magnet slot 11, the second auxiliary slot 22 is located in the opening range of the V-shaped magnet slot 11, and the outer edge cutout 21 should be arranged between the first auxiliary slot 14 and the second auxiliary slot 22.
[0041] The shape of the outer edge cutout 21 is generally a check mark shape, but can also be other shapes, but the position of the outer edge cutout 21 needs to be determined to reduce the motor eccentric radial electromagnetic force density. The determination idea of the position of the outer edge cutout 21 is described below.
[0042] Generally, the outer edge cutout 21 should be located in the high saturation magnetic density area formed by the rotor outer edge, and the outer edge cutout 21 should be located around the center line of the rotor magnetic flux arrangement slot (the first auxiliary slot 14 and the second auxiliary slot 22 are both magnetic flux arrangement slots, and the purpose is to adjust the magnetic line of force) to the extension line of the rotor outer edge, so as to eliminate the high magnetic density area formed by the rotor magnetic flux arrangement slot.
[0043] Please refer to Figure 5 , Figure 5 The position relationship between the outer edge cutout and the first auxiliary slot, the V-shaped magnet slot and the magnetic pole axis provided by the utility model is shown in the schematic view. As shown in the figure, Figure 5 The second corner point 210 is located on the axis 140 of the first auxiliary slot. It should be understood that in this case, the axis of the first auxiliary slot 14 should be able to intersect with the V-shaped magnet slot 11 and the outer edge of the rotor punching sheet as a straight line.
[0044] Further, the opening ends of the outer edge cutout 21 are respectively a first end point 211 and a second end point 212, a line connecting the first end point 211 and the center of the rotor lamination is a first line 101, a line connecting the second corner point 210 and the center of the rotor lamination is a second line 102, a line connecting the second end point 212 and the center of the rotor lamination is a third line 103, an included angle between the first line 101 and the magnetic pole axis 20 is a first included angle, an included angle between the second line 102 and the magnetic pole axis 20 is a second included angle, and an included angle between the third line 103 and the magnetic pole axis 20 is a third included angle, and the absolute value of the difference between the first included angle and the second included angle is greater than or equal to 0.5 degrees, and the absolute value of the difference between the second included angle and the third included angle is greater than or equal to 0.5 degrees. The position of the outer edge cutout 21 can be limited in this way.
[0045] Preferably, when the axis 140 of the first auxiliary slot and the side of the V-shaped magnet slot 11 intersected thereby form an angle, a new principle for limiting the position of the outer edge cutout 21 is introduced. Under this premise, the distance between the second corner point 210 and the first end point 211 should be less than the distance between the second corner point 210 and the second end point 212, and the first end point 211 is farther away from the magnetic pole axis 20 within the opening range of the V of the V-shaped magnet slot 11 than the second end point 212; the angle between the axis 140 of the first auxiliary slot and the side of the V-shaped magnet slot 11 intersected thereby is θ, the first included angle is θ1, the second included angle is θ2, and the third included angle is θ3, and the following conditions are met: θ1-θ2=2.7-(θ-90); θ2-θ3=2.7+(θ-90); if the calculation result of 2.7-(θ-90) or 2.7+(θ-90) is negative, the calculation result is directly taken as 0.5.
[0046] Figure 6 The motor no-load power generation potential waveform change after the through hole 13 and the outer edge cutout 21 are opened in an embodiment of the utility model is shown, the effective value is reduced from the original 44.15V to 44.11V (back EMF drops 0.081% almost unchanged), THD rises from 1.69% to 1.70%, which proves that the through hole 13 of the utility model has little effect on the effective value and waveform of motor back EMF. After adding the outer edge cutout 21, the back EMF is reduced from the original 44.15V to 43.89V (back EMF drops 0.6%), and THD rises from 1.69% to 1.90%.
[0047] Figure 7The output torque under the same current after the through hole 13 and the outer edge notch 21 are opened is shown, which is reduced from 3.975Nm to 3.965Nm (decreased by 0.25%), and the torque fluctuation is increased from 0.514Nm to 0.523Nm (increased by 1.75%), so it can be seen that the through hole 13 has little effect on the motor load operation.
[0048] It should also be noted that although the utility model has been disclosed as above with preferred embodiments, the above embodiments are not intended to limit the utility model. For any skilled person in the art, many possible changes and modifications of the utility model technical solution can be made by using the disclosed technical content, or modified as equivalent embodiments of equivalent changes without departing from the scope of the utility model technical solution. Therefore, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the utility model, which does not deviate from the content of the utility model technical solution, still belongs to the scope of protection of the utility model technical solution.
[0049] It should also be understood that, unless specifically described or indicated, the terms "first", "second", "third" and the like in the specification are merely used to distinguish different components, elements, steps and the like in the specification, and are not intended to represent a logical relationship or sequence relationship between the components, elements, steps and the like.
[0050] In addition, it should be recognized that the terms described herein are only used to describe specific embodiments, and are not intended to limit the scope of the utility model. It must be noted that the singular forms "a" and "an" and "the" used herein and in the appended claims include plural referents unless the context clearly dictates otherwise. For example, reference to "a step" or "a means" means reference to one or more steps or means and can include sub-steps and sub-means. All conjunctions used herein should be interpreted in the broadest possible sense. In addition, the word "or" should be interpreted as having the definition of logical "or", not the definition of logical "exclusive or", unless the context clearly indicates otherwise. In addition, the implementation of the embodiments of the utility model can include manually, automatically or combinedly performing selected tasks.
Claims
1. A rotor lamination, characterized by A plurality of V-shaped magnet grooves are arranged circumferentially on the rotor lamination, and the V-shaped magnet grooves are formed with V-shaped openings facing outward, and any two of the V-shaped rotor magnet grooves have an inter-pole magnetic bridge therebetween; A through hole is arranged on the rotor lamination, the through hole is arranged close to the inter-pole magnetic bridge, the through hole is closer to the centroid of the rotor lamination than the inter-pole magnetic bridge, and the through hole is used to reduce the second-order spatial electromagnetic force density of the rotor lamination.
2. The rotor lamination of claim 1, wherein, The inter-pole magnetic bridge is arranged at an angle with the V-shaped magnet groove to form a first corner point, and the minimum distance between the edge of the through hole and the first corner point is greater than or equal to 0.45 cm and less than or equal to 0.8 cm.
3. The rotor lamination of claim 2, wherein, The minimum distance between the edge of the through hole and the edge of the inter-pole magnetic bridge is greater than or equal to 0.45 cm and less than or equal to 0.8 cm.
4. The rotor lamination of claim 1, wherein, The through hole is circular, and the through hole is also used for inserting a fastener.
5. The rotor lamination of claim 1, wherein, The rotor lamination further comprises a first auxiliary groove, the first auxiliary groove is farther away from the centroid of the rotor lamination than the V-shaped magnet groove, the first auxiliary groove is located within the opening range of the V-shaped magnet groove, and an outer edge cutout is arranged on the outer edge of the rotor lamination, the outer edge cutout is arranged between two adjacent first auxiliary grooves within the opening range of the V-shaped magnet groove.
6. The rotor lamination of claim 5, wherein, The outer edge cutout is arranged between the first auxiliary groove and the magnetic pole axis of the rotor lamination.
7. The rotor lamination of claim 5, wherein, The rotor lamination further comprises a second auxiliary groove, the second auxiliary groove is farther away from the centroid of the rotor lamination than the V-shaped magnet groove, the second auxiliary groove is located within the opening range of the V-shaped magnet groove, and the outer edge cutout is arranged between the first auxiliary groove and the second auxiliary groove.
8. The rotor lamination of claim 5, wherein, The outer edge cutout has a second corner point, and the second corner point is located on the axis of the first auxiliary groove.
9. The rotor lamination of claim 8, wherein, The opening of the outer edge cutout has a first end point and a second end point, the first end point and the centroid of the rotor lamination form a first line, the second corner point and the centroid of the rotor lamination form a second line, the second end point and the centroid of the rotor lamination form a third line, the first line and the magnetic pole axis form a first angle, the second line and the magnetic pole axis form a second angle, and the third line and the magnetic pole axis form a third angle, and the absolute value of the difference between the first angle and the second angle is greater than or equal to 0.5 degrees, and the absolute value of the difference between the second angle and the third angle is greater than or equal to 0.5 degrees.
10. The rotor lamination of claim 8, wherein, The opening of the outer edge cutout has a first end point and a second end point, the first end point and the centroid of the rotor lamination form a first line, the second corner point and the centroid of the rotor lamination form a second line, the second end point and the centroid of the rotor lamination form a third line, the first line and the magnetic pole axis form a first angle, the second line and the magnetic pole axis form a second angle, and the third line and the magnetic pole axis form a third angle; The second corner point is closer to the first end point than to the second end point, the first end point being further away from the magnetic pole axis within the opening range of the V shape of the V-shaped magnet slot than the second end point; The first auxiliary slot has an axis and an angle with the side of the V-shaped magnet slot intersecting the axis, the first angle is θ1, the second angle is θ2, and the third angle is θ3, and the following conditions are met: θ1-θ2=2.7-(θ-90); θ2-θ3=2.7+(θ-90); If the calculation result of 2.7-(θ-90) or 2.7+(θ-90) is negative, the calculation result is directly taken as 0.5.