Rotor assembly, motor, compressor, air conditioner

Abstract

The present invention provides a rotor assembly, a motor, a compressor, and an air conditioner, wherein the rotor assembly includes a rotor core, the rotor core has a plurality of magnetic poles, under the same magnetic pole, the rotor core is constructed with a first magnetic steel slot and a second magnetic steel slot arranged in a V shape, a first magnetic isolation hole symmetrical about the q axis is provided between the second magnetic steel slot and the first magnetic steel slot respectively provided under two adjacent magnetic poles, two magnetic isolation hole groups and second magnetic isolation holes corresponding to the two magnetic isolation hole groups are provided in the V-shaped opening area, and the radial outer side walls of the first magnetic isolation hole, the first magnetic steel slot, the second magnetic steel slot, and the magnetic isolation hole group are at least partially located on the first circle. According to the present invention, it can ensure that the rotor iron loss and the permanent magnet eddy current loss are reduced while the motor output remains basically unchanged, and the motor efficiency is improved; the heat generation and temperature rise of the permanent magnet are reduced, and the possibility of demagnetization of the permanent magnet due to heat generation is avoided, and the operation reliability of the motor is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of motor manufacturing, and in particular relates to a rotor assembly, a motor, a compressor, and an air conditioner. Background Art

[0002] Permanent magnet synchronous motors mostly use neodymium iron boron materials with higher coercive force and remanence, which have high electrical conductivity and poor heat resistance. Compared with copper loss and iron loss, the eddy current loss of permanent magnets is not large in most cases. However, for high-speed motors, high power density motors and motors with closed (or semi-closed) structures, the eddy current loss of permanent magnets will cause a large temperature rise in the local area of ​​the permanent magnets. Under the influence of temperature rise, the permanent magnets will undergo irreversible demagnetization, which will eventually cause the motor to be unable to operate safely and reliably. Summary of the invention

[0003] Therefore, the present invention provides a rotor assembly, a motor, a compressor, and an air conditioner, which can overcome the shortcomings of the related art that the eddy current loss of the permanent magnet and the iron loss of the rotor are large, and at the same time, the eddy current loss of the permanent magnet and the iron loss of the rotor cause the permanent magnet to have a large local temperature rise and is prone to irreversible demagnetization.

[0004] In order to solve the above problems, the present invention provides a rotor assembly, including a rotor core, the rotor core having a plurality of magnetic poles, and under the same magnetic pole, a first magnetic steel slot and a second magnetic steel slot are constructed on the rotor core, the first magnetic steel slot and the second magnetic steel slot are symmetrical about the d axis of the magnetic pole and are V-shaped, the V-shaped opening faces the outer circumferential side of the rotor core, and a first magnetic isolation hole symmetrical about the q axis is provided between the second magnetic steel slot and the first magnetic steel slot respectively provided under two adjacent magnetic poles, and two magnetic isolation hole groups are provided in the V-shaped opening area, the two magnetic isolation hole groups are symmetrical about the d axis and are respectively arranged one by one corresponding to the first magnetic steel slot and the second magnetic steel slot, and a second magnetic isolation hole is also respectively provided one by one on the radial inner side of the two magnetic isolation hole groups, and the two second magnetic isolation holes are symmetrical about the d axis, and the radial outer side walls of the first magnetic isolation hole, the first magnetic steel slot, the second magnetic steel slot and the magnetic isolation hole group are at least partially located on a first circle, and the center of the first circle is concentric with the axis of the rotor core.

[0005] In some embodiments, the first magnetic isolation hole is a rectangular groove, and its circumferential width is a. The minimum distance between the first magnetic isolation hole and the first magnetic steel groove is d, and d / 3<a<5d / 6.

[0006] In some embodiments, a radial length of the first magnetic isolation hole is b, where a<b<1.4a.

[0007] In some embodiments, a radial distance between the first magnetic isolation hole and the outer circumferential wall of the rotor core is g, and 0.3g<b<0.4g.

[0008] In some embodiments, the magnetic isolation hole group includes a third magnetic isolation hole. On the axial projection of the rotor core, the radial inner wall of the third magnetic isolation hole is a straight line, and the angle formed between the radial inner wall and the circumferential side wall of the reference magnetic steel slot is α3, 45°<α3<70°, and the reference magnetic steel slot is the first magnetic steel slot or the second magnetic steel slot adjacent to the third magnetic isolation hole.

[0009] In some embodiments, 55°<α3<60°; and / or, the point on the wall of the third magnetic isolation hole with the smallest distance from the circumferential side wall of the reference magnetic steel slot is the first point, the line between the first point and the axis of the rotor core is the first straight line, the angle between the first straight line and the q-axis adjacent to the reference magnetic steel slot is α1, the point on the wall of the third magnetic isolation hole with the largest distance from the circumferential side wall of the reference magnetic steel slot is the second point, the line between the second point and the axis of the rotor core is the second straight line, the angle between the second straight line and the q-axis adjacent to the reference magnetic steel slot is α2, 8°<α1<α2<2α1<20°.

[0010] In some embodiments, the second magnetic isolation hole has a straight radial outer wall and a straight radial inner wall, the radial outer wall of the second magnetic isolation hole and the radial inner wall of the second magnetic isolation hole can extend to intersect at point A, and the angle formed between the bisector of ∠A and the axial side wall of the reference magnetic steel groove is β3, 65°<β3<70°.

[0011] In some embodiments, the point on the hole wall of the second magnetic isolation hole with the smallest distance from the circumferential side wall of the reference magnetic steel slot is the third point, the line between the third point and the axis of the rotor core is the third straight line, the angle between the third straight line and the q-axis adjacent to the reference magnetic steel slot is β1, the point on the hole wall of the second magnetic isolation hole with the largest distance from the circumferential side wall of the reference magnetic steel slot is the fourth point, the line between the fourth point and the axis of the rotor core is the fourth straight line, the angle between the fourth straight line and the q-axis adjacent to the reference magnetic steel slot is β2, 10°<β1<β2<20°; and / or, the minimum distance between the radial outer wall of the second magnetic isolation hole and the radial inner wall of the second magnetic isolation hole is e, 0.8g<e<g.

[0012] In some embodiments, the distance between the third point and the reference magnetic steel is f, 1.5g<f<1.8g.

[0013] In some embodiments, the magnetic isolation hole group includes a plurality of sub-magnetic isolation holes spaced apart along the circumferential direction of the rotor core.

[0014] In some embodiments, the circumferential spacing between two adjacent sub-magnetic isolation holes is w, 0.3mm≤w≤0.4mm; and / or the sub-magnetic isolation hole away from the d-axis is connected to the first magnetic steel slot or the second magnetic steel slot adjacent thereto.

[0015] The present invention also provides a motor, comprising the above-mentioned rotor assembly.

[0016] The present invention also provides a compressor, comprising the above-mentioned rotor assembly.

[0017] The present invention also provides an air conditioner, comprising the above-mentioned motor or the above-mentioned compressor.

[0018] The present invention provides a rotor assembly, a motor, a compressor, and an air conditioner, which are provided with the first magnetic isolation hole, the second magnetic isolation hole, and the magnetic isolation hole group. The rotor magnetic circuit can be adjusted to block the low-order harmonic magnetic field from entering the rotor core, while having little effect on the fundamental magnetic field, thereby ensuring that the rotor iron loss and permanent magnet eddy current loss generated by the harmonic magnetic field are reduced while the motor output remains basically unchanged, thereby improving the motor efficiency; at the same time, the design of these magnetic isolation holes can also reduce the heating and temperature rise of the permanent magnet caused by the rotor iron loss and the permanent magnet eddy current loss, thereby avoiding the possibility of heating and demagnetization of the permanent magnet, thereby improving the operating reliability of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structure of the rotor assembly of an embodiment of the present invention (axial view);

[0020] Figure 2 It is a partial structural schematic diagram of a rotor assembly according to an embodiment of the present invention (partial dimensions are shown in the figure);

[0021] Figure 3 Another partial structural schematic diagram of a rotor assembly according to an embodiment of the present invention (partial dimensions are shown in the figure);

[0022] Figure 4 It is another partial structural schematic diagram of the rotor assembly of an embodiment of the present invention (partial dimensions are shown in the figure);

[0023] Figure 5 is a partial structural schematic diagram of a rotor assembly according to another embodiment of the present invention;

[0024] Figure 6 It is a partial structural schematic diagram of a rotor assembly according to another embodiment of the present invention;

[0025] Figure 7 A comparison diagram of rotor iron loss between a motor rotor adopting the technical solution of the present invention and a motor rotor in the prior art that does not adopt the technical solution of the present invention;

[0026] Figure 8 The figure is a comparison diagram of eddy current loss of permanent magnets in a motor rotor adopting the technical solution of the present invention and a motor rotor in the prior art that does not adopt the technical solution of the present invention.

[0027] The reference numerals are as follows:

[0028] 1. rotor core; 11. first magnetic steel slot; 12. second magnetic steel slot; 21. first magnetic isolation hole; 22. third magnetic isolation hole; 221. sub-magnetic isolation hole; 23. second magnetic isolation hole; 100. permanent magnet. DETAILED DESCRIPTION

[0029] Embodiment 1:

[0030] See also Figures 1 to 8As shown, according to an embodiment of the present invention, a rotor assembly is provided, including a rotor core 1, the rotor core 1 having a plurality of magnetic poles (uniformly arranged along the circumference of the rotor core 1), under the same magnetic pole, the rotor core 1 is constructed with a first magnetic steel slot 11 and a second magnetic steel slot 12 equipped with a permanent magnet 100, the first magnetic steel slot 11 and the second magnetic steel slot 12 are symmetrical about the d axis of the magnetic pole and are V-shaped, the opening of the V-shaped is toward the outer circumference of the rotor core 1, and there is a space between the second magnetic steel slot 12 and the first magnetic steel slot 11 respectively provided under two adjacent magnetic poles. A first magnetic isolation hole 21 is symmetrical about the q axis, and two magnetic isolation hole groups are arranged in the V-shaped opening area, the two magnetic isolation hole groups are symmetrical about the d axis and correspond to the first magnetic steel slot 11 and the second magnetic steel slot 12 respectively, and a second magnetic isolation hole 23 is also correspondingly arranged on the radial inner side of the two magnetic isolation hole groups, the two second magnetic isolation holes 23 are symmetrical about the d axis, the first magnetic isolation hole 21, the first magnetic steel slot 11, the second magnetic steel slot 12 and the radial outer side wall of the magnetic isolation hole group are at least partially located on a first circle, and the center of the first circle is concentric with the axis of the rotor core 1. In this technical solution, the first magnetic isolation hole 21, the second magnetic isolation hole 23 and the magnetic isolation hole group are provided at the same time, which can adjust the rotor magnetic circuit to block the low-order harmonic magnetic field from entering the rotor core 1, while having little effect on the fundamental magnetic field, thereby ensuring that the rotor iron loss and permanent magnet eddy current loss generated by the harmonic magnetic field are reduced while the motor output remains basically unchanged, thereby improving the motor efficiency; at the same time, the design of these magnetic isolation holes can also reduce the heating and temperature rise of the permanent magnet caused by the rotor iron loss and the permanent magnet eddy current loss, thereby avoiding the possibility of heating and demagnetization of the permanent magnet 100, thereby improving the operating reliability of the motor; in addition, in this technical solution, the radial outer side walls of the first magnetic isolation hole 21, the first magnetic steel slot 11, the second magnetic steel slot 12 and the magnetic isolation hole group are at least partially on the first circle, so as to ensure that the magnetic circuit between the first magnetic isolation hole 21, the first magnetic steel slot 11, the second magnetic steel slot 12 and the radial outer side walls of the magnetic isolation hole group and the outer circle of the rotor are consistent and the core structure strength close to the outer circle of the rotor is consistent.

[0031] In some embodiments, the first magnetic isolation hole 21 is a rectangular slot, and its circumferential width is a, and the minimum spacing between the first magnetic isolation hole 21 and the first magnetic steel slot 11 is d, d / 3<a<5d / 6; the radial length of the first magnetic isolation hole 21 is b, a<b<1.4a; the radial spacing between the first magnetic isolation hole 21 and the outer circumferential wall of the rotor core 1 is g, 0.3g<b<0.4g. By reasonably setting the relative position and size of the first magnetic isolation hole 21, the magnetic circuit of the q-axis can be improved, thereby achieving the effect of blocking the low-order harmonic magnetic field from entering the rotor core 1.

[0032] In some embodiments, the magnetic isolation hole group includes a third magnetic isolation hole 22, and on the axial projection of the rotor core 1, the radial inner wall of the third magnetic isolation hole 22 is a straight line, and the angle formed between the radial inner wall and the circumferential side wall of the reference magnetic steel slot is α3, 45°<α3<70°, the reference magnetic steel slot is the first magnetic steel slot 11 or the second magnetic steel slot 12 adjacent to the third magnetic isolation hole 22, and further, 55°<α3<60°; and / or, the point on the hole wall of the third magnetic isolation hole 22 with the smallest distance from the circumferential side wall of the reference magnetic steel slot is the first point, the line between the first point and the axis of the rotor core 1 is the first straight line, and the first straight line is connected to the adjacent reference magnetic steel slot. The angle between the q axes of the slots is α1, the point on the hole wall of the third magnetic isolation hole 22 with the largest distance from the circumferential side wall of the reference magnetic steel slot is the second point, the line between the second point and the axis of the rotor core 1 is the second straight line, and the angle between the second straight line and the q axis adjacent to the reference magnetic steel slot is α2, 8°<α1<α2<2α1<20°; the second magnetic isolation hole 23 has a straight radial outer wall and a straight radial inner wall, the radial outer wall of the second magnetic isolation hole 23 and the radial inner wall of the second magnetic isolation hole 23 can extend and intersect at point A, and the angle formed between the angular bisector of ∠A and the axial side wall of the reference magnetic steel slot is β3, 65°<β3<70°. In some embodiments, the point on the hole wall of the second magnetic isolation hole 23 with the smallest distance from the circumferential side wall of the reference magnetic steel slot is the third point, the line between the third point and the axis of the rotor core 1 is the third straight line, the angle between the third straight line and the q-axis adjacent to the reference magnetic steel slot is β1, the point on the hole wall of the second magnetic isolation hole 23 with the largest distance from the circumferential side wall of the reference magnetic steel slot is the fourth point, the line between the fourth point and the axis of the rotor core 1 is the fourth straight line, the angle between the fourth straight line and the q-axis adjacent to the reference magnetic steel slot is β2, 10°<β1<β2<20°; and / or, the minimum distance between the radial outer wall of the second magnetic isolation hole 23 and the radial inner wall of the second magnetic isolation hole 23 is e, 0.8g<e<g, and the distance between the third point and the reference magnetic steel is f, 1.5g<f<1.8g. By reasonably setting the relative position and size of the second magnetic isolation hole 23 and the third magnetic isolation hole 22 , they work together to optimize the rotor d-axis magnetic circuit and magnetic field line distribution, thereby reducing the entry of low-order harmonic magnetic fields into the rotor core 1 .

[0033] In summary, by setting the first magnetic isolation hole 21, the second magnetic isolation hole 23 and the third magnetic isolation hole 23, the low-order harmonic magnetic field can be significantly blocked, thereby greatly reducing the rotor iron loss (reduced by 22%) and the permanent magnet eddy current loss (reduced by 60%) caused by the low-order harmonic magnetic field. Figure 7 and Figure 8As shown, the motor structure has the highest overall efficiency, while the permanent magnet temperature rise is minimized, and the possibility of permanent magnet demagnetization due to temperature rise is lowest.

[0034] Embodiment 2:

[0035] Different from the first embodiment, the magnetic isolation hole group includes a plurality of magnetic isolation holes 221 arranged at intervals along the circumference of the rotor core 1, such as Figure 5 As shown, there are three sub-magnetic isolation holes 221, and the three sub-magnetic isolation holes 221 are arranged in sequence along the axial direction of the rotor core 1. The size of the outermost edges of the three sub-magnetic isolation holes 221 is limited to be the same as that of the single third magnetic isolation hole 22, which will not be repeated here. By setting in sections, the blocking effect of the magnetic isolation holes on the fundamental magnetic field can be reduced, but at the same time, the blocking effect on the harmonic magnetic field will also be weakened. The decrease in rotor iron loss and permanent magnet eddy current loss is smaller than that in Example 1, and the overall efficiency is lower than that in Example 1. In some embodiments, the circumferential spacing between two adjacent sub-magnetic isolation holes 221 is w, 0.3mm≤w≤0.4mm. Within this range, the magnetic isolation holes 221 can effectively block low-order harmonics without blocking the passage of the fundamental magnetic field.

[0036] Embodiment 3:

[0037] What is different from Example 2 is that, based on Example 2, the sub-magnetic isolation hole 221 away from the d-axis is connected to the first magnetic steel slot 11 or the second magnetic steel slot 12 adjacent thereto.

[0038] According to an embodiment of the present invention, there is further provided a motor, in particular a permanent magnet synchronous motor, comprising the above-mentioned rotor assembly.

[0039] According to an embodiment of the present invention, a compressor is further provided, comprising the above-mentioned rotor assembly.

[0040] According to an embodiment of the present invention, there is also provided an air conditioner, comprising the above-mentioned motor or the above-mentioned compressor.

[0041] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0042] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention, and these improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A rotor assembly, comprising a rotor core (1), the rotor core (1) having a plurality of magnetic poles, wherein under the same magnetic pole, the rotor core (1) is configured with a first magnetic steel slot (11) and a second magnetic steel slot (12), the first magnetic steel slot (11) and the second magnetic steel slot (12) being symmetrical about the d-axis of the magnetic pole and forming a V-shape, the opening of the V-shape facing the outer circumference of the rotor core (1), characterized in that: A first magnetic isolation hole (21) symmetrical about the q axis is provided between the second magnetic steel slot (12) and the first magnetic steel slot (11) respectively provided under two adjacent magnetic poles; two magnetic isolation hole groups are provided in the V-shaped opening area; the two magnetic isolation hole groups are symmetrical about the d axis and are respectively arranged one-to-one corresponding to the first magnetic steel slot (11) and the second magnetic steel slot (12); a second magnetic isolation hole (23) is also respectively provided one-to-one correspondingly on the radial inner side of the two magnetic isolation hole groups; the two second magnetic isolation holes (23) are symmetrical about the d axis; the first magnetic isolation hole (21), the first magnetic steel slot (11), the second magnetic steel slot (12) and the radial outer side wall of the magnetic isolation hole group are at least partially located on a first circle; the center of the first circle is concentric with the axis of the rotor core (1); the magnetic isolation hole group includes a third magnetic isolation hole (22); in the axial projection of the rotor core (1), the third magnetic isolation hole (22 ) is a straight line, and the angle formed between the radial inner side wall and the circumferential side wall of the reference magnetic steel slot is α3, the reference magnetic steel slot is the first magnetic steel slot (11) or the second magnetic steel slot (12) adjacent to the third magnetic isolation hole (22); the point on the hole wall of the third magnetic isolation hole (22) with the smallest distance from the circumferential side wall of the reference magnetic steel slot is the first point, the line connecting the first point and the axis of the rotor core (1) is the first straight line, the angle between the first straight line and the q-axis adjacent to the reference magnetic steel slot is α1, the point on the hole wall of the third magnetic isolation hole (22) with the largest distance from the circumferential side wall of the reference magnetic steel slot is the second point, the line connecting the second point and the axis of the rotor core (1) is the second straight line, the angle between the second straight line and the q-axis adjacent to the reference magnetic steel slot is α2, 8°<α1<α2<2α1<20°.

2. The rotor assembly according to claim 1, characterized in that: The first magnetic isolation hole (21) is a rectangular slot, and its circumferential width is a. The minimum distance between the first magnetic isolation hole (21) and the first magnetic steel slot (11) is d, and d / 3<a<5d / 6.

3. The rotor assembly according to claim 2, characterized in that: The radial length of the first magnetic isolation hole (21) is b, where a<b<1.4a.

4. The rotor assembly according to claim 3, characterized in that: The radial distance between the first magnetic isolation hole (21) and the outer circumferential wall of the rotor core (1) is g, and 0.3g<b<0.4g.

5. The rotor assembly according to claim 4, characterized in that: 45°＜α3＜70°。 6. The rotor assembly according to claim 5, characterized in that 55°＜α3＜60°。 7. The rotor assembly according to claim 6, characterized in that The second magnetic isolation hole (23) has a straight radial outer wall and a straight radial inner wall, the radial outer wall of the second magnetic isolation hole (23) and the radial inner wall of the second magnetic isolation hole (23) can extend to intersect at point A, and the angle formed between the bisector of ∠A and the axial side wall of the reference magnetic steel groove is β3, 65°<β3<70°.

8. The rotor assembly according to claim 7, characterized in that The point on the hole wall of the second magnetic isolation hole (23) with the smallest distance from the circumferential side wall of the reference magnetic steel slot is the third point, the line connecting the third point and the axis of the rotor core (1) is the third straight line, the angle between the third straight line and the q-axis adjacent to the reference magnetic steel slot is β1, the point on the hole wall of the second magnetic isolation hole (23) with the largest distance from the circumferential side wall of the reference magnetic steel slot is the fourth point, the line connecting the fourth point and the axis of the rotor core (1) is the fourth straight line, the angle between the fourth straight line and the q-axis adjacent to the reference magnetic steel slot is β2, 10°<β1<β2<20°; and / or the minimum distance between the radial outer wall of the second magnetic isolation hole (23) and the radial inner wall of the second magnetic isolation hole (23) is e, 0.8g<e<g.

9. The rotor assembly according to claim 8, characterized in that The distance between the third point and the reference magnetic steel slot is f, 1.5g<f<1.8g.

10. A motor, characterized in that: A rotor assembly comprising any one of claims 1 to 9.

11. A compressor, characterized in that: A rotor assembly comprising any one of claims 1 to 9.

12. An air conditioner, characterized in that: Includes the motor according to claim 10, or the compressor according to claim 11.

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