Low-harmonic permanent magnet motor rotor punching sheet and rotor structure

Abstract

The invention discloses a rotor punching sheet and a rotor structure of a low-harmonic permanent magnet motor, and the rotor punching sheet comprises a rotor punching sheet body, each magnetic pole unit is symmetrically provided with a first V-shaped magnetic steel groove and a second V-shaped magnetic steel groove, and the first V-shaped magnetic steel groove is located between a shaft hole and the second V-shaped magnetic steel groove; a first auxiliary groove, a second auxiliary groove and a third auxiliary groove are formed in the outer circle of the rotor, and the auxiliary grooves in the unit magnetic poles are symmetrically distributed about the d-axis center line. The first auxiliary groove is located between the q-axis center line and the first V-shaped magnetic steel groove, the second auxiliary groove is located between the first V-shaped magnetic steel groove and the second V-shaped magnetic steel groove, and the third auxiliary groove is located between the second V-shaped magnetic steel groove and the d-axis center line. Three pairs of auxiliary grooves are formed in the outer circle of the rotor, and by reasonably designing the topological structure of the double-V-shaped rotor and the shapes and the positions of the auxiliary grooves of the rotor, the distribution of an air-gap magnetic field is optimized, the magnetic field harmonic waves of the motor are weakened, the cogging torque and the torque pulsation of the motor are reduced, and the vibration noise of the motor is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a low-harmonic permanent magnet motor rotor punching and a rotor structure. Background Art

[0002] The prior art discloses a rotor punching and a permanent magnet motor rotor. This solution proposes a case of a built-in double V-shaped topology structure, which improves the vibration and noise of the motor through the optimal double-layer permanent magnet structure and the rotor outer contour line. Its structure is as follows Figure 1 shown.

[0003] This patent divides the outer contour line under each pole of the rotor into three sections, and designs the outer circumference of the rotor through its preferred rotor outer contour line calculation formula, reducing the air gap magnetic field waveform distortion rate, effectively reducing the rotor's slot torque and back-electromotive force harmonic content, and improving the NVH performance of the entire machine. However, the design of the outer contour line of the punching lamination greatly increases the equivalent air gap of the motor, which will reduce the output torque of the motor. At the same time, the rotor structure mainly focuses on the motor's no-load performance and d-axis magnetic circuit design, ignoring the influence of the motor's armature reaction and q-axis magnetic circuit, resulting in the motor's torque pulsation still being high and not significantly improved. Summary of the Invention

[0004] In response to the above-mentioned defects in the prior art, a low-harmonic permanent magnet motor rotor punching and rotor structure are provided, which optimizes the magnetic field line distribution of the rotor magnetic circuit, reduces the influence of the motor armature reaction without affecting the output torque of the motor, and improves the harmonic distortion of the motor air gap magnetic field.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: In a first aspect, a low-harmonic permanent magnet motor rotor lamination includes a rotor lamination body, the rotor lamination body being provided with 2p magnetic pole units, where p is the number of motor pole pairs; each magnetic pole unit being provided with a first V-shaped magnetic steel slot and a second V-shaped magnetic steel slot being symmetrically arranged about an axis d, the first V-shaped magnetic steel slot being located between an axial hole and the second V-shaped magnetic steel slot; The invention is characterized in that: a first auxiliary slot, a second auxiliary slot, and a third auxiliary slot are provided on the outer circle of the rotor, two of each type of auxiliary slot are provided on each unit magnetic pole, and each type of auxiliary slot is symmetrically arranged about the center line of the d-axis on each unit magnetic pole; wherein the first auxiliary slot is located between the center line of the q-axis and the first V-shaped magnetic steel slot, the second auxiliary slot is located between the first V-shaped magnetic steel slot and the second V-shaped magnetic steel slot, and the third auxiliary slot is located between the second V-shaped magnetic steel slot and the center line of the d-axis; Trapezoidal air slots are provided between the first V-shaped magnetic steel slots, and the air slots are arranged symmetrically along the d axis; The inner circle of the rotor includes two convex keys, which are symmetrically arranged on the inner circle of the rotor.

[0006] According to the above technical solution, the three pairs of rotor auxiliary slots adopt an inverted triangle structure. Each auxiliary slot includes an outer edge line away from the d-axis and an inner edge line close to the d-axis. Chamfers are provided at the connection between the inner edge line and the outer circle of the rotor, between the outer edge line and the outer circle of the rotor, and between the inner edge line and the outer edge. The line connecting the intersection of the deepest point of the auxiliary slot and the center of the outer circle of the rotor is used as the center line of the auxiliary slot.

[0007] According to the above technical solution, the angle θ1 between the center line of the first auxiliary groove and the center line of the d-axis satisfies The angle θ2 between the center line of the first auxiliary slot and the other end of the outer edge line and the center of the rotor outer circle satisfies The angle θ3 between the center line of the first auxiliary slot and the other end of the inner edge line and the center of the rotor outer circle satisfies ; The included angle θ4 between the center line of the second auxiliary groove and the center line of the d-axis satisfies The angle θ5 between the center line of the second auxiliary slot and the other end of the outer edge line and the center of the rotor outer circle satisfies The angle θ6 between the center line of the second auxiliary slot and the other end of the inner edge line and the center of the rotor outer circle satisfies ; The included angle θ7 between the center line of the third auxiliary groove and the center line of the d-axis satisfies The angle θ8 between the center line of the third auxiliary slot and the other end of the outer edge line and the center of the rotor outer circle satisfies The angle θ9 between the center line of the third auxiliary slot and the other end of the inner edge line and the center of the rotor outer circle satisfies .

[0008] According to the above technical solution, the outer diameter of the rotor punching is 120mm~123mm, and p is 4; The distance from the deepest part of the rotor auxiliary groove to the outer circle of the rotor is the depth of the rotor auxiliary groove. The depth w1 of the first auxiliary groove satisfies 0.6mm≤w1≤0.8mm, the depth w2 of the second auxiliary groove satisfies 0.5mm≤w2≤0.7mm, and the depth w3 of the third auxiliary groove satisfies 0.4mm≤w3≤0.6mm.

[0009] According to the above technical solution, the angle α1 between the first V-shaped magnetic steel grooves satisfies The pole arc angle α2 between the intersection of the extension line of the inner edge of the two magnetic steel slots near the d-axis and the outer circle of the rotor and the line connecting the center of the circle satisfies The distance H1 between the outer extension line of the first V-shaped magnetic steel slot and the outer circle of the rotor gradually increases from the d-axis along the q-axis direction; The included angle α3 between the second V-shaped magnetic steel slots satisfies The pole arc angle α4 between the intersection of the extension line of the inner edge of the two magnetic steel slots near the d axis and the outer circle of the rotor and the line connecting the center of the circle satisfies ; The distance H4 between the outer extension line of the second V-shaped magnetic steel slot and the outer circle of the rotor gradually increases from the d-axis along the q-axis direction; the lower side of the second V-shaped magnetic steel slot is parallel to the d-axis.

[0010] According to the above technical solution, a trapezoidal air slot is provided between the first V-shaped magnetic steel slots, and the air slots are arranged symmetrically along the d axis. The air slots include upper and lower lines parallel to each other, and side lines connected between the upper and lower lines; the side lines of the air slots are parallel to the lower sides of the magnetic steel slots and form an intermediate magnetic bridge; the center lines of the intermediate magnetic bridges on both sides and the bottom extension lines of the magnetic steel slots on both sides intersect at one point respectively, and the lower line is located on the line connecting the two intersection points; the upper line is obtained after the connecting line of the nearest points of the two magnetic steels is radially translated outward by H2, and H2 satisfies 0.5mm≤H2≤0.8mm.

[0011] According to the above technical solution, it also includes weight-reducing holes and rivet holes. 2p weight-reducing holes are evenly distributed between the magnetic steel slots and the inner circle of the rotor along the circumferential direction; the center of the rivet hole is located on the q axis.

[0012] According to the above technical solution, the inner circle of the rotor includes two convex keys, which are symmetrically arranged on the inner circle of the rotor; according to the angle between the center line of the convex key and the d-axis, the convex key is set in various specifications, and the angle between the symmetrical center line of the convex key and the d-axis of the rotor punching meets , , N is the number of rotor segments, n is an integer.

[0013] In the second aspect, a rotor structure is characterized in that: the low harmonic permanent magnet motor rotor punching as described above is used, and a V-shaped skewed pole method is adopted along the axial direction on the rotor core segment; on the rotor core segment, the rotor skewed pole is symmetrical along the middle of the axial direction, the skewed pole angle intervals of the two adjacent rotor punchings on the single-side core segment are the same, and the maximum skewed pole angle of the rotor core segment is satisfy , where Q is the number of motor slots and N is the number of rotor segments.

[0014] In a third aspect, a permanent magnet motor adopts the rotor structure as described above.

[0015] The present invention has the following beneficial effects: 1. The first auxiliary slot, located between the q-axis centerline and the first V-shaped magnetic steel slot, increases the q-axis magnetic resistance, weakens the motor's q-axis armature reaction, and reduces the motor's torque ripple. The second auxiliary slot, located between the first and second V-shaped magnetic steel slots, adjusts the motor's air gap magnetic field distribution and reduces the harmonic content in the air gap magnetic field. The third auxiliary slot, located between the second V-shaped magnetic steel slot and the d-axis centerline, increases the d-axis magnetic resistance, improves the rotor permanent magnet's anti-demagnetization capability, and weakens the motor's cogging effect, reducing the motor's cogging torque.

[0016] 2. The shape of the three pairs of auxiliary slots and their position relative to the double V-shaped rotor structure improve the air gap magnetic field distribution of the motor, effectively increase the sinusoidality of the air gap magnetic field, reduce the harmonic content, reduce the torque pulsation and electromagnetic force of the motor, and improve the vibration and noise performance of the motor; and because the d-axis and q-axis inductances of the motor are reduced at the same time, the auxiliary slots have little effect on the salient pole ratio of the motor, ensuring the peak torque and peak power performance of the motor output.

[0017] 3. The position and size of the auxiliary slot are defined by adopting the angle between the center line of the auxiliary slot and the center line of the d-axis, the angle between the center line of the auxiliary slot and the line connecting the other end of the outer edge line and the center of the outer circle of the rotor, and the angle between the center line of the auxiliary slot and the line connecting the other end of the inner edge line and the center of the outer circle of the rotor. This method is universally applicable to all outer diameter motor rotors.

[0018] 4. The distance H1 between the outer extension line of the first V-shaped magnetic steel slot and the outer circle of the rotor gradually increases from the d-axis along the q-axis, and the distance H4 between the outer extension line of the second V-shaped magnetic steel slot and the outer circle of the rotor gradually increases from the d-axis along the q-axis, thereby reducing the permanent magnet leakage while meeting the mechanical strength of the rotor.

[0019] 5. The trapezoidal air slot and the first V-shaped magnetic steel slot approximately form a U-shaped topology structure. Compared with the traditional V-shaped magnetic pole structure, it reduces the saturation degree of the motor's q-axis magnetic circuit, increases the motor's q-axis inductance and salient pole ratio, reduces the motor's back electromotive force, improves the motor's output torque and peak power, reduces the motor's magnetic steel usage, and reduces the motor's cost. At the same time, the trapezoidal air slot reduces the rotor weight, divides the middle magnetic bridge of the large V-shaped magnetic steel slot into two, and improves the mechanical strength of the rotor punching.

[0020] 6. The V-shaped slanted poles in the rotor axial direction further weaken the tooth harmonics of the motor, reduce the axial force of the motor, and improve the NVH performance of the motor.

[0021] 7. Setting 2p weight-reducing holes can reduce the weight of the rotor, shorten the response time of the motor during acceleration and deceleration, and improve the power density and torque density of the motor.

[0022] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and to implement it according to the contents of the description, the following preferred embodiments of the present invention are described in detail with reference to the accompanying drawings. The specific implementation methods of the present invention are given in detail by the following embodiments and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0024] Figure 1 It is a schematic diagram of the existing structure; Figure 2 It is a structural schematic diagram of an embodiment provided by the present invention; Figure 3 It is a partial schematic diagram of an embodiment provided by the present invention; Figure 4 Detailed diagram of three auxiliary grooves according to an embodiment of the present invention; Figure 5 This is a detailed view of the first V-shaped magnetic steel slot according to an embodiment of the present invention; Figure 6 This is a detailed view of the second V-shaped magnetic steel slot according to an embodiment of the present invention; Figure 7 Schematic diagram of the rotor inner circle keyway according to an embodiment of the present invention; Figure 8 This is a radial effect diagram of a rotor segmented skewed pole according to an embodiment of the present invention; Figure 9 This is a diagram showing the effect of the rotor axial V-shaped skewed poles according to an embodiment of the present invention; Figure 10 The figure is a comparison of the torque performance between the embodiment of the present invention and other solutions; Figure 11 is a comparison of radial electromagnetic force amplitudes between the embodiment of the present invention and other solutions; In the figure, 1. rotor punching body; 2. first V-shaped magnetic steel slot; 3. second V-shaped magnetic steel slot; 4. first auxiliary slot; 5. second auxiliary slot; 6. third auxiliary slot; 7. trapezoidal air slot; 8. weight reduction hole; 9. rivet hole; 10. key; 11. magnetic steel; 12. shaft hole. DETAILED DESCRIPTION

[0025] The following is combined with Figures 2 to 11The principles and features of the present invention are described, and the examples given are only for the purpose of explaining the present invention and are not intended to limit the scope of the present invention. The following paragraphs describe the present invention in more detail by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are in a very simplified form and are not in exact proportions, and are only used for the purpose of conveniently and clearly assisting in illustrating the embodiments of the present invention.

[0026] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a central component. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] Reference Figures 2 to 11 As shown, the present invention provides a low harmonic permanent magnet motor rotor punching.

[0029] Example 1 It includes a rotor punching body 1, on which 2p magnetic pole units are provided, where p is the number of motor pole pairs; on each magnetic pole unit, a first V-shaped magnetic steel slot 2 and a second V-shaped magnetic steel slot 3 are symmetrically arranged about the d axis, and the first V-shaped magnetic steel slot is located between the shaft hole 12 and the second V-shaped magnetic steel slot.

[0030] A first auxiliary slot 4, a second auxiliary slot 5, and a third auxiliary slot 6 are provided on the outer circumference of the rotor. Two of each type of auxiliary slot are provided on each unit magnetic pole. Each type of auxiliary slot is symmetrically arranged about the centerline of the d-axis on each unit magnetic pole. The first auxiliary slot is located between the centerline of the q-axis and the first V-shaped magnetic steel slot, the second auxiliary slot is located between the first V-shaped magnetic steel slot and the second V-shaped magnetic steel slot, and the third auxiliary slot is located between the second V-shaped magnetic steel slot and the centerline of the d-axis. Trapezoidal air slots 7 are provided between the first V-shaped magnetic steel slots, and the air slots are arranged symmetrically along the d axis; The inner circle of the rotor includes two convex keys 10, which are symmetrically arranged on the inner circle of the rotor.

[0031] The first auxiliary slot, located between the q-axis centerline and the first V-shaped magnetic steel slot, increases the q-axis magnetic resistance, weakens the motor's q-axis armature reaction, and reduces torque ripple. The second auxiliary slot, located between the first and second V-shaped magnetic steel slots, adjusts the air gap magnetic field distribution and reduces harmonic content in the air gap magnetic field. The third auxiliary slot, located between the second V-shaped magnetic steel slot and the d-axis centerline, increases the d-axis magnetic resistance, improving the rotor permanent magnet's resistance to demagnetization, while also weakening the motor's cogging effect and reducing the motor's cogging torque.

[0032] In Example 1, a preferred auxiliary slot structure is provided. Three pairs of rotor auxiliary slots adopt an inverted triangular structure. Each auxiliary slot includes an outer edge away from the d-axis and an inner edge closer to the d-axis. Chamfers are provided at the junctions between the inner edge and the rotor outer circumference, between the outer edge and the rotor outer circumference, and between the inner edge and the outer edge. The centerline of the auxiliary slot is defined by the line connecting the intersection of the deepest point of the auxiliary slot and the center of the rotor outer circumference.

[0033] The shape of the three pairs of auxiliary slots and their position relative to the double V-shaped rotor structure improve the air-gap magnetic field distribution of the motor, effectively increase the sinusoidality of the air-gap magnetic field, reduce the harmonic content, reduce the torque pulsation and electromagnetic force of the motor, and improve the vibration and noise performance of the motor; and because the d-axis and q-axis inductances of the motor are reduced at the same time, the auxiliary slots have little effect on the salient pole ratio of the motor, thus ensuring the peak torque and peak power performance of the motor output.

[0034] Preferably, specific design dimensions of the auxiliary groove are given.

[0035] like Figures 3 and 4 As shown, the included angle θ1 between the center line of the first auxiliary groove and the center line of the d-axis satisfies The angle θ2 between the center line of the first auxiliary slot and the other end of the outer edge line and the center of the rotor outer circle satisfies The angle θ3 between the center line of the first auxiliary slot and the other end of the inner edge line and the center of the rotor outer circle satisfies ; The included angle θ4 between the center line of the second auxiliary groove and the center line of the d-axis satisfies The angle θ5 between the center line of the second auxiliary slot and the other end of the outer edge line and the center of the rotor outer circle satisfies The angle θ6 between the center line of the second auxiliary slot and the other end of the inner edge line and the center of the rotor outer circle satisfies ; The included angle θ7 between the center line of the third auxiliary groove and the center line of the d-axis satisfies The angle θ8 between the center line of the third auxiliary slot and the other end of the outer edge line and the center of the rotor outer circle satisfies The angle θ9 between the center line of the third auxiliary slot and the other end of the inner edge line and the center of the rotor outer circle satisfies .

[0036] In the above preferred embodiment, by adopting the above-mentioned various angles to define the position and size of the auxiliary groove, it is universally applicable to all outer diameter motor rotors. In some embodiments, the outer diameter of the rotor punching is 120mm~123mm, and p is 4. Then, the width of the center line of the first auxiliary groove and the center line of the d-axis on the outer circumference of the rotor meets 21.7mm~24.2mm, the width of the line connecting the center line of the first auxiliary groove and the other end of the outer edge line with the center of the outer circle of the rotor on the outer circumference of the rotor meets 0.7mm~1.4mm, and the width of the line connecting the center line of the first auxiliary groove and the other end of the inner edge line with the center of the outer circle of the rotor on the outer circumference of the rotor meets 0.7mm~1.4mm.

[0037] The width of the center line of the second auxiliary groove and the center line of the d-axis on the outer circumference of the rotor meets the requirements of 13.2mm~15.0mm, the width of the line connecting the center line and the other end of the outer edge line of the second auxiliary groove and the center of the outer circle of the rotor on the outer circumference of the rotor meets the requirements of 2.8mm~3.9mm, and the width of the line connecting the center line and the other end of the inner edge line of the second auxiliary groove and the center of the outer circle of the rotor on the outer circumference of the rotor meets the requirements of 0.7mm~1.4mm.

[0038] The width of the center line of the third auxiliary groove and the center line of the d-axis on the outer circumference of the rotor meets the requirements of 6.6mm~8.2mm, the width of the line connecting the center line and the other end of the outer edge line of the third auxiliary groove and the center of the outer circle of the rotor on the outer circumference of the rotor meets the requirements of 1.4mm~2.4mm, and the width of the line connecting the center line and the other end of the inner edge line of the third auxiliary groove and the center of the outer circle of the rotor on the outer circumference of the rotor meets the requirements of 1.4mm~2.4mm.

[0039] The distance from the deepest part of the rotor auxiliary groove to the outer circle of the rotor is the depth of the rotor auxiliary groove. The depth w1 of the first auxiliary groove satisfies 0.6mm≤w1≤0.8mm, the depth w2 of the second auxiliary groove satisfies 0.5mm≤w2≤0.7mm, and the depth w3 of the third auxiliary groove satisfies 0.4mm≤w3≤0.6mm.

[0040] Example 2 The structure and principle of Example 2 are similar to those of Example 1, except that a preferred structure of the magnetic steel slot is provided based on Example 1. However, the structure of the present invention is not limited to the following structural dimensions.

[0041] like Figure 3 、 5 As shown in 6, the angle α1 between the first V-shaped magnetic steel slots satisfies The pole arc angle α2 between the intersection of the extension line of the inner edge of the two magnetic steel slots near the d-axis and the outer circle of the rotor and the line connecting the center of the circle satisfies The distance H1 between the outer extension line of the first V-shaped magnetic steel slot and the outer circle of the rotor gradually increases from the d-axis along the q-axis direction, thereby reducing the permanent magnet leakage while meeting the mechanical strength of the rotor; The included angle α3 between the second V-shaped magnetic steel slots satisfies The pole arc angle α4 between the intersection of the extension line of the inner edge line of the two magnetic steels 11 placed in the second V-shaped magnetic steel slot close to the d-axis and the outer circle of the rotor and the line connecting the center of the circle satisfies ; The distance H4 between the outer extension line of the second V-shaped magnetic steel slot and the outer circle of the rotor gradually increases from the d-axis along the q-axis direction, reducing the permanent magnet leakage while meeting the mechanical strength of the rotor; the lower side of the second V-shaped magnetic steel slot is parallel to the d-axis.

[0042] Example 3 The structure and principle of Example 3 are similar to those of Example 2, with the difference being that the trapezoidal air slot and the first V-shaped magnetic steel slot approximately form a U-shaped topology structure. Compared with the traditional V-shaped magnetic pole structure, it reduces the saturation degree of the motor's q-axis magnetic circuit, increases the motor's q-axis inductance and salient pole ratio, reduces the motor's back electromotive force, increases the motor's output torque and peak power, reduces the motor's magnetic steel usage, and reduces the motor's cost. At the same time, the trapezoidal air slot reduces the rotor weight, divides the middle magnetic bridge of the large V-shaped magnetic steel slot into two, and improves the mechanical strength of the rotor punchings.

[0043] A trapezoidal air slot is provided between the first V-shaped magnetic steel slots. The air slots are arranged symmetrically along the d axis. The air slots include upper and lower lines parallel to each other, and side lines connected between the upper and lower lines. The side lines of the air slots are parallel to the lower sides of the magnetic steel slots and form an intermediate magnetic bridge. The center lines of the intermediate magnetic bridges on both sides and the bottom extension lines of the magnetic steel slots on both sides intersect at one point respectively, and the lower line is located on the line connecting the two intersection points. The upper line is obtained by radially translating the connecting line of the nearest points of the two magnetic steels outward by H2, and H2 satisfies 0.5mm≤H2≤~0.8mm.

[0044] In Examples 1-3, weight-reducing holes 8 and rivet holes 9 are also included. Two weight-reducing holes are evenly distributed along the circumference between the magnetic steel slots and the rotor inner circle. The rivet holes are centered on the q-axis. The rivet holes are used for lamination of rotor punchings, and the weight-reducing holes are used to reduce the rotor's moment of inertia.

[0045] Example 4 The structure and principle of embodiment 4 are similar to those of embodiments 1-3, except that: Figures 7-9 As shown, according to the angle between the center line of the key and the d-axis, the key is set in various specifications, and the angle between the symmetrical center line of the key and the d-axis of the rotor punching meets , , N is the number of rotor segments, n is an integer.

[0046] The rotor's inner circumference is equipped with a key that matches the slot on the shaft. The key's position is adjusted to achieve segmented axial rotor skewing. As shown in the figure, rotor skewing can effectively reduce the tooth harmonic components in the motor's magnetic field and suppress the motor's vibration and noise. The angle β between the key's centerline and the d-axis is the rotor skewing angle for that segment, and the β value varies between different rotor core segments. As shown in the figure, the three-segment skewing effect diagram has skewing angles of β, 0, and -β, respectively. As shown in the figure, the rotor adopts a V-shaped skewing method. The rotor skewing is symmetrical along the middle of the axial direction. The difference in skewing angles between adjacent core segments on one side is the same, which can reduce the axial force of the motor and improve the NVH performance of the motor.

[0047] The present invention also provides a rotor structure.

[0048] The low harmonic permanent magnet motor rotor punching is used as described above, and a V-shaped skewed pole method is adopted on the rotor core segment along the axial direction; on the rotor core segment, the rotor skewed pole is symmetrical along the middle of the axial direction, and the skewed pole angle intervals of the two adjacent rotor punching segments of the single-side core segment are the same, and the maximum skewed pole angle of the rotor core segment is satisfy , where Q is the number of motor slots and N is the number of rotor segments.

[0049] by Figure 9 For example, its oblique polar angles are -β, 0, β, β, 0, -β.

[0050] The present invention also provides a motor, such as Figures 7-9 As shown, it includes the above-mentioned rotor structure.

[0051] Taking an 8-pole 48-slot motor as an example, the number of rotor pole pairs p is 4, and the number of axial segments N is 6. The motor's first V-shaped magnetic steel angle α1 is in the range of 76.5°~85.5°, the pole arc angle α2 of the first V-shaped magnetic steel slot is in the range of 30.15°~32.4°, the second V-shaped magnetic steel angle α3 is in the range of 99°~135°, and the second pole arc angle α4 of the second V-shaped magnetic steel slot is in the range of 17.1°~18.9°. The rotor axial distribution adopts the following method: Figure 9 In the 6-stage slant-pole mode shown, β is in the range of 2.25° to 2.75°.

[0052] There are eight rotor poles distributed along the outer surface of the rotor. Each rotor pole has three pairs of auxiliary slots, which are symmetrical along the d-axis. Auxiliary slot 1 is located between the first V-shaped magnetic steel slot and the q-axis, with a central angle θ1 ranging from 20.7° to 22.5°, and outer angles θ2 and θ3 both ranging from 0.675° to 1.35°. Auxiliary slot 2 is located between the first and second V-shaped magnetic steel slots, with a central angle θ4 ranging from 12.6° to 14.4°, an outer angle θ5 ranging from 2.7° to 3.6°, and an inner angle θ6 ranging from 0.675° to 1.35°. Auxiliary slot 3 is located between the second V-shaped magnetic steel slot and the d-axis, with a central angle θ7 ranging from 6.3° to 7.65°, and outer angles θ8 and θ9 both ranging from 1.35° to 2.25°.

[0053] As shown in Table 1, the dual V-shaped rotor structure described in Examples 2-4 can achieve lower motor torque pulsation. Traditional design schemes mostly only provide auxiliary slots on the rotor d-axis, which can effectively reduce the torque pulsation of the motor, but have little effect on weakening the radial electromagnetic force and tangential electromagnetic force of the motor; and further adopting the three pairs of rotor auxiliary slot structures described in Example 1, under the same current excitation, the peak output torque of the motor remains basically unchanged, while the torque pulsation is further reduced, and the amplitudes of the main order radial electromagnetic force and tangential electromagnetic force of the motor are also effectively attenuated, which can greatly improve the NVH performance of the motor.

[0054] Table 1

[0055] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in this industry can smoothly implement the present invention as shown in the drawings and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of protection of the technical solution of the present invention.

Claims

1. A low-harmonic permanent magnet motor rotor lamination, comprising a rotor lamination body, the rotor lamination body being provided with 2p magnetic pole units, where p is the number of motor pole pairs; each magnetic pole unit being provided with a first V-shaped magnetic steel slot and a second V-shaped magnetic steel slot symmetrically arranged about an axis d, the first V-shaped magnetic steel slot being located between an axial hole and the second V-shaped magnetic steel slot; Its characteristics are: A first auxiliary slot, a second auxiliary slot, and a third auxiliary slot are provided on the outer circumference of the rotor. Two of each type of auxiliary slot are provided on each unit magnetic pole. Each type of auxiliary slot is symmetrically arranged about the d-axis centerline on each unit magnetic pole. The first auxiliary slot is located between the q-axis centerline and the first V-shaped magnetic steel slot, the second auxiliary slot is located between the first V-shaped magnetic steel slot and the second V-shaped magnetic steel slot, and the third auxiliary slot is located between the second V-shaped magnetic steel slot and the d-axis centerline. Trapezoidal air slots are provided between the first V-shaped magnetic steel slots, and the air slots are arranged symmetrically along the d axis; The inner circle of the rotor includes two convex keys, which are symmetrically arranged on the inner circle of the rotor.

2. The low harmonic permanent magnet motor rotor punching according to claim 1, characterized in that: The three pairs of rotor auxiliary slots adopt an inverted triangle structure. Each auxiliary slot includes an outer edge line away from the d-axis and an inner edge line close to the d-axis. Chamfers are provided at the connection between the inner edge line and the rotor outer circle, between the outer edge line and the rotor outer circle, and between the inner edge line and the outer edge. The center line of the auxiliary slot is the line connecting the intersection of the deepest point of the auxiliary slot and the center of the rotor outer circle.

3. The low harmonic permanent magnet motor rotor punching according to claim 2, characterized in that: The included angle θ1 between the center line of the first auxiliary groove and the center line of the d-axis satisfies The angle θ2 between the center line of the first auxiliary slot and the other end of the outer edge line and the center of the rotor outer circle satisfies The angle θ3 between the center line of the first auxiliary slot and the other end of the inner edge line and the center of the rotor outer circle satisfies ; The included angle θ4 between the center line of the second auxiliary groove and the center line of the d-axis satisfies The angle θ5 between the center line of the second auxiliary slot and the other end of the outer edge line and the center of the rotor outer circle satisfies The angle θ6 between the center line of the second auxiliary slot and the other end of the inner edge line and the center of the rotor outer circle satisfies ; The included angle θ7 between the center line of the third auxiliary groove and the center line of the d-axis satisfies The angle θ8 between the center line of the third auxiliary slot and the other end of the outer edge line and the center of the rotor outer circle satisfies The angle θ9 between the center line of the third auxiliary slot and the other end of the inner edge line and the center of the rotor outer circle satisfies .

4. The low harmonic permanent magnet motor rotor punching according to any one of claims 1 to 3, characterized in that: The outer diameter of the rotor punching is 120mm~123mm, and p is 4; The distance from the deepest part of the rotor auxiliary groove to the outer circle of the rotor is the depth of the rotor auxiliary groove. The depth w1 of the first auxiliary groove satisfies 0.6mm≤w1≤0.8mm, the depth w2 of the second auxiliary groove satisfies 0.5mm≤w2≤0.7mm, and the depth w3 of the third auxiliary groove satisfies 0.4mm≤w3≤0.6mm.

5. The low harmonic permanent magnet motor rotor punching according to claim 1, characterized in that: The included angle α1 between the first V-shaped magnetic steel slots satisfies The pole arc angle α2 between the intersection of the extension line of the inner edge of the two magnetic steel slots near the d-axis and the outer circle of the rotor and the line connecting the center of the circle satisfies The distance H1 between the outer extension line of the first V-shaped magnetic steel slot and the outer circle of the rotor gradually increases from the d-axis along the q-axis direction; The included angle α3 between the second V-shaped magnetic steel slots satisfies The pole arc angle α4 between the intersection of the extension line of the inner edge of the two magnetic steel slots near the d axis and the outer circle of the rotor and the line connecting the center of the circle satisfies ; The distance H4 between the outer extension line of the second V-shaped magnetic steel slot and the outer circle of the rotor gradually increases from the d-axis along the q-axis direction; the lower side of the second V-shaped magnetic steel slot is parallel to the d-axis.

6. The low harmonic permanent magnet motor rotor punching according to claim 5, characterized in that: The air slot includes an upper side line and a lower side line parallel to each other, and a side line connected between the upper and lower side lines; the side line of the air slot is parallel to the lower side of the magnetic steel slot and forms an intermediate magnetic bridge; the center line of the intermediate magnetic bridge on both sides and the bottom extension line of the magnetic steel slot on both sides intersect at one point respectively, and the lower side line is located on the line connecting the two intersection points; the upper side line is obtained by radially translating the connecting line of the nearest points of the two magnetic steels outward by H2, and H2 satisfies 0.5mm≤H2≤0.8mm.

7. The low harmonic permanent magnet motor rotor punching according to claim 1, characterized in that: It also includes weight-reducing holes and rivet holes. The 2p weight-reducing holes are evenly distributed along the circumferential direction between the magnetic steel slots and the inner circle of the rotor; the center of the rivet hole is located on the q axis.

8. The low harmonic permanent magnet motor rotor punching according to any one of claims 1 to 7, characterized in that: According to the angle between the center line of the key and the d-axis, the key is set in various specifications. The angle between the symmetrical center line of the key and the d-axis of the rotor punching meets , , N is the number of rotor segments, n is an integer.

9. A rotor structure, characterized in that: The low harmonic permanent magnet motor rotor punching as claimed in claim 8 is used, and a V-shaped skewed pole method is adopted on the rotor core segment along the axial direction; on the rotor core segment, the rotor skewed pole is symmetrical along the middle of the axial direction, the skewed pole angle intervals of the two adjacent rotor punchings of the single-side core segment are the same, and the maximum skewed pole angle 2nβ of the rotor core segment satisfies , where Q is the number of motor slots and N is the number of rotor segments.

10. A permanent magnet motor, characterized in that: The rotor structure according to claim 9 is adopted.

Images