Rotor lamination, motor, compressor and air conditioner

Abstract

The application discloses a rotor lamination, a motor, a compressor and an air conditioner. The rotor lamination comprises a plurality of magnetic poles, and a magnetic steel slot is arranged below the magnetic pole. A magnetic isolation structure is arranged between the magnetic steel slot and the periphery of the rotor lamination. The magnetic isolation structure comprises n first magnetic isolation holes and m second magnetic isolation holes. The n first magnetic isolation holes are uniformly distributed on the two sides of the center line of the corresponding magnetic steel slot and are away from the center line. The m second magnetic isolation holes are uniformly distributed on the two sides of the center line of the corresponding magnetic steel slot and are close to the center line. The width of the first magnetic isolation hole decreases in the direction from the center of the rotor lamination to the center of the rotor lamination. The width of the second magnetic isolation hole increases in the direction from the center of the rotor lamination to the center of the rotor lamination. n and m are even numbers not less than 2. The two different magnetic isolation holes can reduce torque ripple. The width of the magnetic isolation hole is limited to improve the magnetic density and then improve the circulating flow. The motor efficiency is improved by improving the circulating flow. Meanwhile, the cogging torque can be reduced, and the 12S8P motor 4-order 8-fold frequency and 0-order 24-fold frequency electromagnetic force are greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of compressor technology and relates to a rotor lamination, a motor, a compressor, and an air conditioner. Background Technology

[0002] The rapid development and widespread application of refrigeration equipment has promoted the rapid advancement of variable frequency compressor technology. Currently, commonly used variable frequency compressors generally use built-in permanent magnet motors. This type of motor is already very mature. Customers not only have high performance requirements, but also require low noise in air conditioners. The motor is the source of compressor noise. After the motor is energized, the time and space harmonics of the combined magnetic field generated by the interaction between the stator magnetic field and the rotor will produce significant vibration noise. Summary of the Invention

[0003] In view of this, the present invention provides a rotor lamination, a motor, a compressor, and an air conditioner, which solves the problem of temporal and spatial harmonics in the synthetic magnetic field generated by the interaction between the stator magnetic field and the rotor after the traditional motor is powered on, thus causing large vibration noise.

[0004] To address the aforementioned problems, according to one aspect of this application, an embodiment of the present invention provides a rotor lamination comprising a plurality of magnetic poles, each magnetic pole having a magnetic slot distributed beneath it; each magnetic slot having a magnetic isolation structure between it and the periphery of the rotor lamination, the magnetic isolation structure comprising n first magnetic isolation holes and m second magnetic isolation holes, the n first magnetic isolation holes being evenly distributed on both sides of the center line of the corresponding magnetic slot and away from the center line, the m second magnetic isolation holes being evenly distributed on both sides of the center line of the corresponding magnetic slot and close to the center line, the width of the first magnetic isolation holes gradually decreasing and the width of the second magnetic isolation holes gradually increasing along the direction from the center of the rotor lamination away from the center of the rotor lamination; wherein, n and m are both even numbers not less than 2.

[0005] In some embodiments, the first magnetic isolation hole is shaped like a first trapezoid, and the second magnetic isolation hole is shaped like a second trapezoid. The included angle between the two sides of the first trapezoid is a, and the included angle between the two sides of the second trapezoid is b. The angle between a and b satisfies: 0 ≤ b ≤ a ≤ 35°.

[0006] In some embodiments, the angle between the angle bisector of a and the center line of the corresponding magnetic pole is c, where c>0, and the angle between the angle bisector of b and the center line of the corresponding magnetic pole is d, where d≤45°.

[0007] In some embodiments, the height of the first trapezoid is L1, and the distance between the intersection of the angle bisector of a with the inner surface of the magnet slot 1 and the intersection with the outer periphery of the rotor lamination is L11; the height of the second trapezoid is L2, and the distance between the intersection of the angle bisector of b with the inner surface of the magnet slot 1 and the intersection with the outer periphery of the rotor lamination is L22; L1, L11, L2, and L22 satisfy the following condition: 2.2≥(L11 / L1)≥(L22 / L2)≥1.7; wherein, the inner surface of the magnet slot 1 is the side of the magnet slot 1 that is close to the outer periphery of the rotor lamination.

[0008] In some embodiments, the n first magnetic isolation holes are symmetrical about the center line of the corresponding magnetic groove 1; the m second magnetic isolation holes are symmetrical about the center line of the corresponding magnetic groove.

[0009] In some embodiments, the angle between the angle bisector of a and the base of the first trapezoid is f, and the angle between the angle bisector of b and the base of the second trapezoid is e, where f and e satisfy: f ≥ e ≥ 90°.

[0010] In some embodiments, the distance between the intersection of the angle bisector of a with the base of the first trapezoid and the intersection with the inner surface of the magnet slot is L3, and the distance between the intersection of the angle bisector of b with the base of the second trapezoid and the intersection with the inner surface of the magnet slot is L4. L3 and L4 satisfy: 1.0 < (L4 / L3) < 1.2; wherein, the base of the first trapezoid is the side of the first trapezoid closest to the center of the rotor lamination, and the base of the second trapezoid is the side of the second trapezoid closest to the center of the rotor lamination.

[0011] In some embodiments, the area S1 of the first magnetic isolation hole and the area S2 of the second magnetic isolation hole satisfy the following condition: 1.5 < (S2 / S1) ≤ 1.65.

[0012] In some embodiments, in the first trapezoid, two adjacent sides are transitioned by a first circular arc with a radius of R1. In the second trapezoid, two adjacent sides are transitioned by a second circular arc with a radius of R2. R1 and R2 satisfy the following condition: R1 = R2 and R1 ≥ 0.3 mm.

[0013] According to another aspect of this application, an embodiment of the present invention provides an electric motor comprising the rotor laminations described above.

[0014] According to another aspect of this application, an embodiment of the present invention provides a compressor that includes the motor described above.

[0015] According to another aspect of this application, an embodiment of the present invention provides an air conditioner including the compressor described above.

[0016] Compared with the prior art, the rotor laminations of the present invention have at least the following beneficial effects:

[0017] The rotor lamination provided by this invention includes multiple magnetic poles, each with a magnetic slot distributed below it. Each magnetic slot has a magnetic isolation structure between itself and the periphery of the rotor lamination. The magnetic isolation structure includes n first magnetic isolation holes and m second magnetic isolation holes. The n first magnetic isolation holes are evenly distributed on both sides of the center line of the corresponding magnetic slot and away from the center line. The m second magnetic isolation holes are evenly distributed on both sides of the center line of the corresponding magnetic slot and close to the center line. Along the direction from near the center of the rotor lamination to away from the center, the width of the first magnetic isolation holes gradually decreases, and the width of the second magnetic isolation holes gradually increases. Wherein, n and m are both even numbers not less than 2.

[0018] This invention reduces torque pulsation by employing two different magnetic isolation holes, improves magnetic flux density by limiting the width of the magnetic isolation holes, and thus improves circulating current. This improved circulating current can enhance motor efficiency and reduce cogging torque, significantly reducing the electromagnetic force of the 12S8P motor at 4th order 8th harmonic and 0th order 24th harmonic frequencies.

[0019] The motor provided by this invention is designed based on the above-mentioned rotor laminations, and its beneficial effects are the same as those of the above-mentioned rotor laminations, which will not be repeated here.

[0020] The compressor provided by this invention is designed based on the above-mentioned motor, and its beneficial effects are the same as those of the above-mentioned motor, which will not be repeated here.

[0021] The air conditioner provided by this invention is designed based on the above-mentioned compressor, and its beneficial effects are the same as those of the above-mentioned compressor, which will not be repeated here.

[0022] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a rotor lamination provided in an embodiment of the present invention;

[0025] Figure 2 This is an indicator diagram of a, b, c, and d in a rotor lamination provided by an embodiment of the present invention;

[0026] Figure 3This is an indication diagram of R1 and R2 in a rotor lamination provided by an embodiment of the present invention;

[0027] Figure 4 This is an indicator diagram of L1, L2, L11 and L22 in a rotor lamination provided by an embodiment of the present invention;

[0028] Figure 5 yes Figure 4 A magnified view of a section at point A in the middle;

[0029] Figure 6 This is an indicator diagram of L3, L4, S1 and S2 in a rotor lamination provided by an embodiment of the present invention;

[0030] Figure 7 yes Figure 6 A magnified view of a section at point B in the middle;

[0031] Figure 8 This is a magnetic field distribution diagram of a magnetic isolation structure in a rotor lamination provided by an embodiment of the present invention, when the included angles a and b are not defined;

[0032] Figure 9 This is a magnetic field distribution diagram of a magnetic isolation structure in a rotor lamination provided by an embodiment of the present invention, where the included angles c and d are not defined;

[0033] Figure 10 This is a magnetic field distribution diagram of a magnetic isolation structure in a rotor lamination provided by an embodiment of the present invention, after the included angle is defined;

[0034] Figure 11 This is a comparison diagram between the prior art and the electromagnetic force of the 12S8P motor with the 4th order 8th harmonic frequency in this embodiment;

[0035] Figure 12 This is a comparison diagram of the existing technology and the electromagnetic force of the 12S8P motor at 0th order 24 times frequency in this embodiment.

[0036] in:

[0037] 1. Magnetic steel channel; 2. Magnetic shielding structure; 3. Permanent magnet; 21. First magnetic shielding hole; 22. Second magnetic shielding hole. Detailed Implementation

[0038] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific embodiments, structures, features, and effects according to the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "an embodiment" or "an embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0039] In the description of this invention, it should be clearly stated that the terms "first," "second," etc., in the specification, claims, and accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence; the terms "vertical," "lateral," "longitudinal," "front," "rear," "left," "right," "up," "down," "horizontal," etc., indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, and are merely for the convenience of describing this invention, and do not mean that the device or element referred to must have a specific orientation or position, and therefore should not be construed as a limitation of this invention.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] Example 1

[0042] This embodiment provides a rotor lamination, such as Figure 1 As shown, the rotor lamination includes multiple magnetic poles, and each magnetic pole has a magnetic slot 1 distributed below it. Each magnetic slot 1 has a magnetic isolation structure 2 between it and the periphery of the rotor lamination. The magnetic isolation structure 2 includes n first magnetic isolation holes 21 and m second magnetic isolation holes 22. The n first magnetic isolation holes 21 are evenly distributed on both sides of the center line of the corresponding magnetic slot 1 and away from the center line. The m second magnetic isolation holes 22 are evenly distributed on both sides of the center line of the corresponding magnetic slot 1 and close to the center line. Along the direction from the center of the rotor lamination to the direction away from the center of the rotor lamination, the width of the first magnetic isolation holes 21 gradually decreases and the width of the second magnetic isolation holes 22 gradually increases. Here, n and m are both even numbers not less than 2.

[0043] Specifically, the rotor lamination has multiple magnetic poles, and two magnetic steel slots 1 symmetrically distributed at a certain angle are arranged under each magnetic pole. Multiple permanent magnets 3 are placed in the magnetic steel slots 1, and the permanent magnets 3 in each set of magnetic steel slots 1 form magnetic poles. The magnetic properties of adjacent sets of magnetic poles are opposite. On the cross-section of each rotor lamination, the line connecting the center of each set of magnetic poles to the rotation axis of the rotor forms the d-axis. Magnetic isolation structures 2 are provided on both sides of the d-axis, near the outer periphery of the rotor lamination in the magnetic steel slots 1. For better illustration of this embodiment, it is assumed that n and m are both 2, and the magnetic steel... The center line of slot 1 divides the magnet slot 1 into a first magnet slot and a second magnet slot. The magnetic isolation structure 2 is specifically as follows: In the space formed by the first magnet slot and the outer periphery of the rotor lamination, along the direction from the center line of the corresponding magnet slot 1 to the direction away from the center line of the magnet slot 1, a second magnetic isolation hole 22 and a first magnetic isolation hole 21 are distributed in sequence; In the space formed by the second magnet slot and the outer periphery of the rotor lamination, along the direction from the center line of the corresponding magnet slot 1 to the direction away from the center line of the magnet slot 1, a second magnetic isolation hole 22 and a first magnetic isolation hole 21 are distributed in sequence.

[0044] More specifically, both the first magnetic isolation hole 21 and the second magnetic isolation hole 22 are quadrilateral structures, namely the first side, the second side, the third side and the fourth side. Assuming that the first side is a side close to the outer periphery of the rotor and the fourth side is a side close to the magnetic slot 1, then the second side and the third side are two opposite sides. Along the direction from the center of the rotor lamination to the direction away from the center of the rotor lamination, the distance between the second side and the third side of the first magnetic isolation hole 21 gradually decreases, and the distance between the second side and the third side of the second magnetic isolation hole 22 gradually increases.

[0045] This invention reduces torque pulsation by employing two different magnetic isolation holes, improves magnetic flux density by limiting the width of the magnetic isolation holes, and thus improves circulating current. This improved circulating current can enhance motor efficiency and reduce cogging torque, significantly reducing the electromagnetic force of the 12S8P motor at 4th order 8th harmonic and 0th order 24th harmonic frequencies.

[0046] In a specific embodiment, such as Figure 2 As shown, the first magnetic isolation hole 21 is in the shape of a first trapezoid, and the second magnetic isolation hole 22 is in the shape of a second trapezoid. The included angle between the two sides of the first trapezoid is a, and the included angle between the two sides of the second trapezoid is b. The angle between a and b satisfies: 0 ≤ b ≤ a ≤ 35°.

[0047] Among them, the two waists are the second and third sides mentioned above. The included angles a and b are in opposite directions, with included angle a pointing outwards from the rotor and included angle b pointing inwards from the rotor. Figure 8 This is a diagram showing the magnetic field lines distribution of the magnetic isolation structure when the included angles a and b are not specified. Figure 10The diagram shows the magnetic field distribution of the magnetic isolation structure after the included angle is limited. It can be seen from the diagram that when the included angle is limited, the magnetic field of the first magnetic isolation hole 21 is unevenly distributed in the air gap. However, when 0≤b≤a≤35, the magnetic field is evenly distributed, which can improve the electromagnetic force of the motor. Beyond this range, the motor noise will increase, which is not conducive to the user experience.

[0048] In a specific embodiment, such as Figure 2 As shown, the angle between the angle bisector of a and the center line of the corresponding magnetic pole is c, where c>0, and the angle between the angle bisector of b and the center line of the corresponding magnetic pole is d, where d≤45°.

[0049] Specifically, when the rotor rotates, the back electromotive force generated by the stator windings with the rotor magnets cut off is not an ideal sine wave. Fourier decomposition yields the useful fundamental wave, while the remaining harmonics (3rd, 5th, 7th...) are harmful to the motor, generating noise and affecting user experience. The lower the harmonic order, the greater the proportion of the motor's electromagnetic force; generally, the 3rd and 5th harmonics are of particular concern. This embodiment reduces the proportion of the 3rd harmonic back electromotive force by limiting the angle. However, a larger angle is not always better; as the angle increases, the 5th and 7th harmonics increase. Therefore, it is necessary to maintain a reasonable harmonic distribution while considering the compressor pump body structure. This reduces the 3rd harmonic without affecting motor performance and torque output, while preventing the 5th and 7th harmonics from increasing and affecting compressor noise. The optimal angle between the trapezoids corresponding to the first and second magnetic isolation holes 21 and 22 is achieved by optimizing the electromagnetic force.

[0050] Figure 9 This is a diagram showing the magnetic field lines distribution of the magnetic isolation structure when the included angles c and d are not specified. Figure 10 The figure shows the magnetic field distribution of the magnetic isolation structure after the included angle is limited. It can be seen from the figure that when the included angle corresponding to the second magnetic isolation hole 22 is not limited, the second magnetic isolation angle will be too large, which will cause the magnetic resistance of the center magnetic field lines to be uneven. After the angle is limited, the magnetic field lines are evenly distributed.

[0051] In a specific embodiment, such as Figure 4 As shown, the height of the first trapezoid is L1, and the distance between the intersection of the angle bisector of a with the inner surface of the magnet slot 1 and the intersection with the outer periphery of the rotor lamination is L11; the height of the second trapezoid is L2, and the distance between the intersection of the angle bisector of b with the inner surface of the magnet slot 1 and the intersection with the outer periphery of the rotor lamination is L22; L1, L11, L2, and L22 satisfy the following condition: 2.2 ≥ (L11 / L1) ≥ (L22 / L2) ≥ 1.7; wherein, the inner surface of the magnet slot 1 is the side of the magnet slot 1 closest to the outer periphery of the rotor lamination.

[0052] Since the first magnetic isolation hole 21 and the second magnetic isolation hole 22 are air slots, their magnetic reluctance is much greater than that of the iron core. Therefore, the magnetic field lines of the motor always follow the path of minimum magnetic reluctance. However, adjusting the width of the path through the iron core also affects the magnetic field distribution. A narrower path with more magnetic lines can lead to local saturation of the iron core's magnetic flux density. Magnetic flux density saturation can also increase the Q-axis magnetic reluctance. Increasing the magnetic reluctance will affect the output force, but it is better for noise reduction. Therefore, the parameters need to be continuously optimized and adjusted. In this embodiment, the distance limitation can adjust the q-axis magnetic reluctance. If the trapezoidal magnetic isolation slot is too close to the outer edge of the rotor, it will cause magnetic circuit saturation, affecting torque output. At the same time, when the silicon steel sheets are in a saturated state, the iron core loss increases, and the motor efficiency decreases. By adjusting the position of the trapezoidal magnetic isolation hole, the distribution of the motor's magnetic field lines is optimized to be uniform without affecting the motor efficiency.

[0053] In a specific embodiment, n first magnetic isolation holes 21 are symmetrical about the center line of the corresponding magnetic steel groove 1; m second magnetic isolation holes 22 are symmetrical about the center line of the corresponding magnetic steel groove 1.

[0054] For better illustration, let's assume that both n and m are 2. Then, symmetrically distributed on both sides of the center line of the corresponding magnet slot 1, from near the center line of the magnet slot 1 to away from the center line of the magnet slot 1, are two second magnetic isolation holes 22 and two first magnetic isolation holes 21. More specifically, let's assume that the center line of the magnet slot 1 divides the space between the magnet slot 1 and the outer periphery of the rotor lamination into a first space and a second space. In the first space, from near the center line of the magnet slot 1 to away from the center line of the magnet slot 1, are one second magnetic isolation hole 22 and one first magnetic isolation hole 21. In the second space, from near the center line of the magnet slot 1 to away from the center line of the magnet slot 1, are one second magnetic isolation hole 22 and one first magnetic isolation hole 21. The first magnetic isolation holes 21 in the first space and the second space are symmetrical about the center line of the magnet slot 1, and the second magnetic isolation holes 22 in the first space and the second space are also symmetrical about the center line of the magnet slot 1.

[0055] In a specific embodiment, such as Figure 3 As shown, the angle between the angle bisector of a and the base of the first trapezoid is f, and the angle between the angle bisector of b and the base of the second trapezoid is e. f and e satisfy: f≥e≥90°. Since the magnetic lines of force of the magnetized steel enter the iron core perpendicularly, the angle between the magnetic steel groove 1 and the magnetic lines of force is obtuse. In order to make the magnetic lines of force more inclined to the d-axis and thus increase the torque output, f≥e≥90° is satisfied.

[0056] In a specific embodiment, such as Figure 4 and Figure 5As shown, the distance between the intersection of the angle bisector of a with the base of the first trapezoid and the intersection with the inner surface of the magnet slot 1 is L3, and the distance between the intersection of the angle bisector of b with the base of the second trapezoid and the intersection with the inner surface of the magnet slot 1 is L4. L3 and L4 satisfy: 1.0 < (L4 / L3) < 1.2; wherein, the base of the first trapezoid is the side of the first trapezoid closest to the center of the rotor lamination, and the base of the second trapezoid is the side of the second trapezoid closest to the center of the rotor lamination.

[0057] The distance L3 between the intersection of the angle bisector of a with the base of the first trapezoid and the intersection with the inner surface of the magnet slot 1, and the distance L4 between the intersection of the angle bisector of b with the base of the second trapezoid and the intersection with the inner surface of the magnet slot 1, cannot be too close to the magnetic isolation slot, otherwise it will cause difficulties in the process, nor can it be too far, otherwise it will have a significant impact on the motor performance. In this embodiment, L3 and L4 are limited to satisfying: 1.0 < (L4 / L3) < 1.2 to ensure that it is easy to implement in the process and will not affect the performance of the motor.

[0058] In a specific embodiment, such as Figure 6 As shown, the area S1 of the first magnetic isolation hole 21 and the area S2 of the second magnetic isolation hole 22 satisfy the following condition: 1.5 < (S2 / S1) ≤ 1.65; the positions of the first magnetic isolation hole 21 and the second magnetic isolation hole 22 can provide part of the refrigerant channel, reduce the temperature of the motor rotor magnet, and reduce the risk of high temperature demagnetization of the motor magnet under high load conditions.

[0059] In a specific embodiment, such as Figure 3 As shown, in the first trapezoid, two adjacent sides are transitioned by a first circular arc with a radius of R1. In the second trapezoid, two adjacent sides are transitioned by a second circular arc with a radius of R2. R1 and R2 satisfy the following conditions: R1 = R2 and R1 ≥ 0.3 mm. That is, using a quarter-circle arc with a radius greater than 0.3 mm to transition between two adjacent sides can ensure the strength of the first magnetic isolation hole 21 and the second magnetic isolation hole 22 with the outer edge of the rotor lamination, i.e., the magnetic steel slot edge structure.

[0060] Example 2

[0061] This embodiment provides an electric motor, which includes the rotor laminations of Embodiment 1.

[0062] The motor provided in this embodiment includes the rotor laminations of Embodiment 1, and all the advantages of the rotor laminations of Embodiment 1 can be embodied in the motor of this embodiment; specifically, as follows Figure 11 The diagram shows a comparison of the 4th-order 8th-harmonic electromagnetic force of the 12S8P motor under conventional technology and the technology of this embodiment. Figure 12The figure shows a comparison of the electromagnetic force of the 12S8P motor at 0th order 24 times the frequency under the traditional technology and the technology of this embodiment. As can be seen from the figure, the electromagnetic force of the motor provided in this embodiment is significantly reduced, which has a better effect on the performance of the motor and the suppression of vibration and noise.

[0063] Example 3

[0064] This embodiment provides a compressor, which includes the motor of Embodiment 2.

[0065] The compressor provided in this embodiment includes the motor in Embodiment 2, and therefore has all the beneficial effects of the motor in Embodiment 2 or the rotor laminations in Embodiment 1.

[0066] Example 4

[0067] This embodiment provides an air conditioner, which includes the compressor of Embodiment 3.

[0068] The air conditioner provided in this embodiment has all the beneficial effects of the rotor laminations in Embodiment 1, the motor in Embodiment 2, or the compressor in Embodiment 3.

[0069] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous technical features can be freely combined and superimposed.

[0070] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A rotor lamination, the rotor lamination comprising a plurality of magnetic poles, each magnetic pole having a magnetic slot distributed beneath it; characterized in that, Each of the magnetic slots has a magnetic isolation structure between itself and the periphery of the rotor lamination. The magnetic isolation structure includes n first magnetic isolation holes and m second magnetic isolation holes. The n first magnetic isolation holes are evenly distributed on both sides of the center line of the corresponding magnetic slot and away from the center line. The m second magnetic isolation holes are evenly distributed on both sides of the center line of the corresponding magnetic slot and close to the center line. Along the direction from the center of the rotor lamination to the direction away from the center of the rotor lamination, the width of the first magnetic isolation holes gradually decreases and the width of the second magnetic isolation holes gradually increases. Wherein, n and m are both even numbers not less than 2. The first magnetic isolation hole is in the shape of a first trapezoid, and the second magnetic isolation hole is in the shape of a second trapezoid. The included angle between the two sides of the first trapezoid is a, and the included angle between the two sides of the second trapezoid is b. The angle between a and b satisfies: 0 ≤ b ≤ a ≤ 35°. The height of the first trapezoid is L1, and the distance between the intersection of the angle bisector of a with the inner surface of the magnet slot and the intersection with the outer periphery of the rotor lamination is L11; the height of the second trapezoid is L2, and the distance between the intersection of the angle bisector of b with the inner surface of the magnet slot and the intersection with the outer periphery of the rotor lamination is L22; L1, L11, L2, and L22 satisfy the following condition: 2.2 ≥ (L11 / L1) ≥ (L22 / L2) ≥ 1.7; wherein, the inner surface of the magnet slot is the side of the magnet slot close to the outer periphery of the rotor lamination.

2. The rotor lamination according to claim 1, characterized in that, The angle between the angle bisector of line a and the center line of the corresponding magnetic pole is c, where c > 0; and the angle between the angle bisector of line b and the center line of the corresponding magnetic pole is d, where d ≤ 45°.

3. The rotor lamination according to claim 1 or 2, characterized in that, The n first magnetic isolation holes are symmetrical about the center line of the corresponding magnetic steel groove; the m second magnetic isolation holes are symmetrical about the center line of the corresponding magnetic steel groove.

4. The rotor lamination according to claim 3, characterized in that, The angle between the angle bisector of a and the base of the first trapezoid is f, and the angle between the angle bisector of b and the base of the second trapezoid is e. f and e satisfy: f ≥ e ≥ 90°.

5. The rotor lamination according to claim 4, characterized in that, The distance between the intersection of the angle bisector of a with the base of the first trapezoid and the intersection with the inner surface of the magnet slot is L3. The distance between the intersection of the angle bisector of b with the base of the second trapezoid and the intersection with the inner surface of the magnet slot is L4. L3 and L4 satisfy: 1.0 < (L4 / L3) < 1.

2. Wherein, the base of the first trapezoid is the side of the first trapezoid closest to the center of the rotor lamination, and the base of the second trapezoid is the side of the second trapezoid closest to the center of the rotor lamination.

6. The rotor lamination according to claim 1 or 2, characterized in that, The area S1 of the first magnetic isolation hole and the area S2 of the second magnetic isolation hole satisfy the following condition: 1.5 < (S2 / S1) ≤ 1.

65.

7. The rotor lamination according to claim 1 or 2, characterized in that, In the first trapezoid, two adjacent sides are transitioned by a first circular arc with a radius of R1. In the second trapezoid, two adjacent sides are transitioned by a second circular arc with a radius of R2. R1 and R2 satisfy the following condition: R1 = R2 and R1 ≥ 0.3 mm.

8. An electric motor, characterized in that, The motor includes the rotor laminations as described in any one of claims 1-7.

9. A compressor, characterized in that, The compressor includes the motor as described in claim 8.

10. An air conditioner, characterized in that, The air conditioner includes the compressor as described in claim 9.

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