Permanent magnet motor rotor

Abstract

This invention discloses a permanent magnet motor rotor, formed by stacking a first circular lamination and a second circular lamination. This allows the harmonic distortions generated by the two types of laminations in the rotor core to compensate for each other. The first circular lamination has six evenly spaced first magnetic slots circumferentially. Triangular magnetic barrier short slots are provided at both ends near the outer periphery of the first circular lamination. The bottom edges of the two magnetic barrier short slots are equidistant from the tangents of the first circular lamination. The central angle between the intersection of the facing waist edges and the corresponding bottom edges of the two magnetic barrier short slots and the Q-axis is A1. The second circular lamination has six evenly spaced second magnetic slots circumferentially. Long magnetic barrier slots are provided at both ends near the outer periphery of the second circular lamination. The central angle between the wedge head of each long magnetic barrier slot and the Q'-axis is B1; central angle A1 is less than B1. This rotor enables the harmonic distortions of the two types of laminations to cancel each other out, significantly reducing the overall back electromotive force distortion rate, optimizing the overall sine of the magnetic field waveform, and achieving low-vibration and low-noise operation of the motor.

Description

Technical Field

[0001] This invention relates to a permanent magnet motor rotor, belonging to the field of permanent magnet motor technology. Background Technology

[0002] In the prior art, CN120880010A discloses a motor rotor and a motor. The outer circle of the rotor core is formed by connecting a first straight segment, an arc segment, a second straight segment, and an arc segment in sequence. Since the cross-section of the core is a non-circular structure, the air gap of the motor is uneven, and airflow pulsation is easily generated when rotating at high speed, thereby causing airflow noise. Summary of the Invention

[0003] The main objective of this invention is to solve the problems of high vibration and noise in existing motors by providing a permanent magnet motor rotor.

[0004] Therefore, this invention provides a permanent magnet motor rotor, comprising a rotor core and rotor magnets. The improvement lies in that the rotor core is formed by stacking first and second circular laminations with different structures, allowing the harmonic distortions generated by the first and second circular laminations in the rotor core to compensate for each other. Specifically, each first circular lamination has six evenly spaced first magnet slots circumferentially spaced. Each first magnet slot has a magnetic barrier short-slot at both ends near the outer periphery of the first circular lamination. The magnetic barrier short-slot is a triangular slot, and two magnetic barrier short-slots... The bottom edges of the slots are equally spaced from the tangents of the first circular lamination. The central angle between the intersection point of the two opposing short magnetic barrier slots and the corresponding bottom edge and the Q axis is A1. The second circular lamination has six second magnetic steel slots evenly spaced around its circumference. Each second magnetic steel slot has a long magnetic barrier slot at both ends near the outer periphery of the second circular lamination. The central angle between the wedge of each long magnetic barrier slot and the Q' axis is B1. The central angle A1 is smaller than the central angle B1 and both are acute angles. The first magnetic steel slots and the second magnetic steel slots are configured with rotor magnets.

[0005] Furthermore, the first circular lamination and the second circular lamination are stacked in a ratio of 1:1 to 1:1.3.

[0006] Furthermore, the central angle A1 is between 5.5° and 6.5°; the central angle B1 is between 9.5° and 10.5°.

[0007] Furthermore, the first magnetic steel groove is axially symmetrically arranged, and the short magnetic barrier slots at both ends of the first magnetic steel groove are symmetrically arranged about the axis of symmetry of the first magnetic steel groove; the second magnetic steel groove is axially symmetrically arranged, and the long magnetic barrier slots at both ends of the second magnetic steel groove are symmetrically arranged about the axis of symmetry of the second magnetic steel groove.

[0008] Compared to existing permanent magnet rotors that consist of stacked laminations of a single structure, the technical solution of this invention has the following advantages and beneficial effects:

[0009] Harmonic cancellation is achieved by stacking two circular laminations with different magnetic barrier structures, which cancels out the harmonic distortions generated by different laminations during the core replacement of the six-slot rotor, significantly reducing the overall back electromotive force waveform distortion rate.

[0010] Vibration reduction and noise reduction eliminate harmonic distortion at the source, optimize the overall sinusoidality of the magnetic field waveform, reduce electromagnetic vibration and airflow pulsation, and achieve low vibration and low noise operation of the motor.

[0011] It has strong versatility. Both types of laminations are circular in structure, which avoids the airflow pulsation caused by uneven air gap in the motor due to non-circular cross sections, thus overcoming airflow noise and facilitating manufacturing. Attached Figure Description

[0012] Figure 1 This is a plan view of the first circular lamination in the rotor of the permanent magnet motor of the present invention;

[0013] Figure 2 This is a plan view of the second circular lamination in the permanent magnet motor rotor of the present invention;

[0014] Figure 3 yes Figure 1 Enlarged view of M;

[0015] Figure 4 yes Figure 2 Enlarged view of the middle W;

[0016] Figure 5 This is a stacked structure diagram of one embodiment of the permanent magnet motor rotor of the present invention;

[0017] Figure 6 It is a comparison diagram of the back electromotive force waveform of a rotor with the first and second circular laminations stacked in a ratio of 1.4:1.6 and a standard sine waveform;

[0018] Figure 7 It is a comparison diagram of the back electromotive force waveform of a rotor with the first and second circular laminations stacked in a 1:1 ratio and a standard sine waveform;

[0019] Figure 8 It is a waveform diagram of the back electromotive force of a rotor using a single stacked first circular lamination;

[0020] Figure 9 It is a waveform diagram of the back electromotive force of a rotor that uses a single stack of second circular laminations. Detailed Implementation

[0021] Please see Figures 1-4As shown, the magneto rotor includes a rotor core 1 and rotor magnets 2. The rotor core 1 is formed by stacking a first circular lamination 11 and a second circular lamination 12 with the same number of magnet slots but different short-slot structures with magnetic barriers, so that the harmonic distortion generated by the first circular lamination 11 and the second circular lamination 12 in the rotor core 1 can compensate for each other. See also Figure 1 The first circular lamination 11 has six evenly spaced first magnetic slots 110. Each first magnetic slot has a magnetic barrier short slot 111 at both ends near the outer periphery of the first circular lamination 11. The magnetic barrier short slot 111 is a triangular slot. The tangents from the bottom edges 1111 of the two magnetic barrier short slots to the first circular lamination 11 are equally spaced. The central angle formed between the line connecting the intersection point of the facing waist edges 1112 of the two magnetic barrier short slots and the corresponding bottom edges 1111 through the center point O and the Q axis is A1. Furthermore, the facing waist edges 1112 of the two magnetic barrier short slots and their respective bottom edges 1111 form an equal first acute angle. See Figure 2 The second circular lamination 12 has six evenly spaced second magnetic slots 120 around its circumference. Each second magnetic slot has a magnetic barrier slot 121 at both ends near the outer periphery of the second circular lamination 12. In this embodiment, the magnetic barrier slots 121 are all wedge-shaped slots, and the central angle formed between the line connecting the wedge head 1211 of each wedge-shaped slot through the center point O' and the Q' axis is Bl. Figure 1 , 2 As shown, the central angle A1 is smaller than the central angle B1, and the central angle B1 is larger than the central angle A1, both of which are acute angles. The rotor magnet 2 is adapted to be installed in the first magnet slot 110 and the second magnet slot 120. The first circular lamination 11 and the second circular lamination 12 are stacked in a ratio of 1:1 to 1:1.3. The ratio of the two laminations can be flexibly adjusted to adapt to permanent magnet motors of different power while taking into account electromagnetic performance. The circular laminations with two different magnetic barrier slots can be stacked alternately, mixed, or segmented. Under the premise of meeting the aforementioned ratio, segmented stacking is preferred to facilitate the identification of the structural type of the circular laminations by the stacking equipment.

[0022] The central angle A1 is 6°±0.5°; the central angle B1 is 10°±0.5°.

[0023] The first magnet slot 110 is axially symmetrical, and the short magnetic barrier slots 111 at both ends of the first magnet slot are symmetrically arranged about the axis of symmetry of the first magnet slot 110. The second magnet slot 120 is axially symmetrical, and the long magnetic barrier slots 121 at both ends of the second magnet slot are symmetrically arranged about the axis of symmetry of the second magnet slot 120. The inner ends of the first magnet slot 110 and the second magnet slot 120 are interconnected to form a V-shape, and after the two types of laminations are stacked, they form a V-shaped cavity along the same axis. Two rotor magnets 2 are installed in each V-shaped cavity.

[0024] The short magnetic barrier slot 111 and the long magnetic barrier slot 121 are stacked together to form the magnetically shielding air cavity of the rotor core 1, which is used to block magnetic leakage and optimize the sinusoidal nature of the air gap magnetic field.

[0025] The rotor core 1 can be formed by stacking a first circular rotor core segment with first circular laminations 11 and a second circular rotor core segment with second circular laminations. In one specific embodiment, two types of circular laminations are stacked in a 1:1 ratio. With this ratio, the motor exhibits a back EMF distortion rate of 2.38% at 3600 rpm under no-load conditions (see...). Figure 7 This rotor core can significantly improve the overall sinusoidal nature of the back electromotive force waveform (compared to...). Figure 8 , 9 (As can be seen from the comparison), at 3600 rpm under no-load conditions... Figure 8 , 9 The back EMF wave distortion rates shown are 16.2% and 14.3%, respectively.

[0026] In another specific implementation, see Appendix Figure 5 As shown, the rotor core 1 is composed of two upper and lower first circular rotor core segments 1A and a middle second circular rotor core segment 1B stacked together. The stack height h1 of each first circular rotor core segment 1A is 19mm, and the stack height h2 of each second circular rotor core segment 1B is 42mm, for a total stack height H of 80mm. This structure, when stacked in a 1.4:1.6 ratio, further optimizes the harmonic cancellation effect of the two types of circular laminations. The motor with circular laminations in this ratio exhibits a back EMF distortion rate of only 2.26% under no-load conditions at 3600rpm (see...). Figure 6 ).

Claims

1. A permanent magnet motor rotor, comprising a rotor core and rotor magnets, characterized in that: The rotor core is formed by stacking first and second circular laminations with different structures, allowing the harmonic distortions generated by the first and second circular laminations in the rotor core to compensate for each other. The first circular lamination has six first magnetic slots evenly spaced around its circumference. Each first magnetic slot has a magnetic barrier short slot at both ends near the outer periphery of the first circular lamination. The magnetic barrier short slot is a triangular slot. The bottom edge of each magnetic barrier short slot is equally spaced from the tangent of the first circular lamination. The central angle between the intersection point of the two opposing waist edges of the magnetic barrier short slots and the corresponding bottom edge and the Q axis is A1. The second circular stamp has six second magnetic slots evenly distributed around its circumference. Each second magnetic slot has a magnetic barrier slot at both ends near the outer periphery of the second circular stamp. The central angle between the wedge head of each magnetic barrier slot and the Q' axis is B1. The central angle A1 is smaller than the central angle B1, and both are acute angles. The first magnet slot and the second magnet slot are jointly configured with rotor magnets.

2. The permanent magnet motor rotor according to claim 1, characterized in that: The first circular lamination and the second circular lamination are stacked in a ratio of 1:1 to 1:1.

3.

3. The permanent magnet motor rotor according to claim 1 or 2, characterized in that: The central angle A1 is between 5.5° and 6.5°; the central angle B1 is between 9.5° and 10.5°.

4. The permanent magnet motor rotor according to claim 3, characterized in that: The first magnet groove is axially symmetrical, and the short magnetic barrier cavities at both ends of the first magnet groove are symmetrically arranged about the axis of symmetry of the first magnet groove; the second magnet groove is axially symmetrical, and the long magnetic barrier cavities at both ends of the second magnet groove are symmetrically arranged about the axis of symmetry of the second magnet groove.

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