Rotor of permanent magnet motor, permanent magnet motor and compressor

Abstract

The present invention discloses a rotor of a permanent magnet motor, a permanent magnet motor and a compressor. The rotor includes a rotor core and a plurality of permanent magnets. The rotor core has a center hole and a plurality of magnet slots. The plurality of magnet slots are arranged along the circumference of the center hole. Each magnet slot extends along the radial direction of the center hole. The parts of each magnet slot located at the radial ends of each permanent magnet form a first magnetic isolation slot. The rotor core is provided with a second magnetic isolation slot on at least one side of the circumference of each magnet slot. The second magnetic isolation slot divides the single-side area into a plurality of magnetic field paths distributed radially. In two radially adjacent magnetic field paths, the minimum width of the magnetic field path located on the radial outer side is smaller than the minimum width of the magnetic field path located on the radial inner side. The permanent magnet motor according to the embodiment of the present invention improves the magnetization characteristics of the rotor core and reduces the noise of the permanent magnet motor.

Description

Technical Field

[0001] The present invention relates to the field of compressors, and in particular to a rotor of a permanent magnet motor, a permanent magnet motor and a compressor. Background Art

[0002] Embedded permanent magnet motors are divided into two structures according to the direction of magnetic flux: radial flux and tangential flux. In the tangential flux structure permanent magnet motor, the permanent magnets in the rotor are arranged along the radial direction of the rotor. In the tangential flux structure permanent magnet motor, since both working surfaces of the permanent magnets face the air gap directly, the magnetic flux utilization rate is higher than that of the radial flux structure, which is more conducive to achieving high efficiency and miniaturization.

[0003] However, since one end of the permanent magnet of the tangential flux structure extends into the vicinity of the inner hole of the rotor, it is difficult to saturate the magnetization after the permanent magnet is inserted into the rotor. This problem is one of the technical difficulties of the tangential flux structure motor. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a rotor of a permanent magnet motor, which can improve the magnetization characteristics and facilitate the magnetization magnetic field to penetrate deeply into the rotor.

[0005] The present invention also aims to provide a permanent magnet motor having the rotor of the permanent magnet motor.

[0006] The present invention also aims to provide a compressor having the permanent magnet motor.

[0007] According to an embodiment of the present invention, the rotor of a permanent magnet motor comprises: a rotor core, the rotor core having a center hole and a plurality of magnet slots, the plurality of magnet slots being arranged along the circumference of the center hole, and each of the magnet slots extending along the radial direction of the center hole; a plurality of permanent magnets, the plurality of permanent magnets being inserted into the plurality of magnet slots one by one, and each of the magnet slots forming at least one first magnetic isolation slot located at both radial ends of each permanent magnet; in addition, the rotor core is provided with a second magnetic isolation slot on at least one side of the circumference of each magnet slot, the second magnetic isolation slot divides the single-sided area where it is located into a plurality of magnetic field paths distributed radially, the single-sided area being the area between the circumference of the center hole and the outer circumference of the rotor core corresponding to the second magnetic isolation slot, and in at least one group of two radially adjacent magnetic field paths, the minimum width of the magnetic field path located on the radial outside is smaller than the minimum width of the magnetic field path located on the radial inside.

[0008] According to the rotor of the permanent magnet motor of the embodiment of the present invention, since the rotor core is provided with a second magnetic isolation groove on at least one side of each magnet slot in the circumferential direction, the second magnetic isolation groove divides the single-side area where it is located into a plurality of magnetic field paths distributed radially, and in two radially adjacent magnetic field paths, the minimum width of the magnetic field path located on the radially outer side is smaller than the minimum width of the magnetic field path located on the radially inner side, which is conducive to the magnetizing magnetic field penetrating from the outer periphery of the rotor core to the inner periphery of the rotor for magnetization, thereby ensuring the magnetization of the rotor core near one end of the permanent magnet close to the center hole, improving the magnetization characteristics of the rotor core, and in addition, it can also improve the air gap magnetic density waveform of the permanent magnet motor, reduce the harmonic content, and thus improve the noise of the permanent magnet motor.

[0009] In some embodiments, a plurality of the second magnetic isolation grooves are provided on both circumferential sides of each of the magnet slots, and the plurality of the second magnetic isolation grooves located on one circumferential side of each of the magnet slots are spaced apart in the radial direction.

[0010] In some specific embodiments, the cross-section of each of the second magnetic isolation grooves is formed as a parallelogram, and in the plurality of second magnetic isolation grooves on one circumferential side of each of the magnet grooves, the side edges of the plurality of second magnetic isolation grooves on both circumferential sides are coplanar.

[0011] In some more specific embodiments, the angle between the second magnetic isolation groove and the magnet groove toward the outer peripheral edge of the rotor core is an acute angle.

[0012] In some embodiments, a magnetic bridge is provided between the second magnetic isolation slot and the adjacent magnet slot.

[0013] In some embodiments, the second magnetic isolation groove is connected to the adjacent magnet groove.

[0014] In some embodiments, the first magnetic isolation groove located radially inside the permanent magnet has a long strip-shaped protrusion protruding radially outward on its inner wall facing the center of the rotor core.

[0015] In some embodiments, the permanent magnet is a rare earth permanent magnet or a ferrite permanent magnet.

[0016] A permanent magnet motor according to an embodiment of the present invention includes the rotor of the permanent magnet motor described above.

[0017] The permanent magnet motor according to the embodiment of the present invention has the permanent magnet motor rotor as described above, so the working noise of the permanent magnet motor is reduced and the working efficiency of the permanent magnet motor is improved.

[0018] A compressor according to an embodiment of the present invention includes a permanent magnet motor.

[0019] The permanent magnet motor according to the embodiment of the present invention has the permanent magnet motor as described above, which reduces the working noise of the compressor and improves the working efficiency of the compressor.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0022] Figure 1 is a schematic structural diagram of a rotor of a permanent magnet motor according to a first embodiment of the present invention;

[0023] Figure 2 yes Figure 1 Schematic diagram of the saturation degree of the core during magnetization of the rotor;

[0024] Figure 3 is a schematic structural diagram of a rotor according to a second embodiment of the present invention;

[0025] Figure 4 Schematic diagram of air gap flux density of the permanent magnet motor of the present invention compared with the prior art;

[0026] Figure 5 is a structural schematic diagram of a permanent magnet motor according to an embodiment of the present invention;

[0027] Figure 6 Schematic diagram of the compressor according to an embodiment of the present invention.

[0028] Reference numerals:

[0029] Compressor 1,

[0030] Permanent magnet motor 10,

[0031] Rotor 100,

[0032] Rotor core 110,

[0033] Magnet slot 111,

[0034] The first magnetic isolation groove 112,

[0035] Bump 1121,

[0036] The second magnetic isolation groove 113,

[0037] Magnetic field passage 114,

[0038] The inner magnetic field passage 114a, the outer magnetic field passage 114b,

[0039] Center hole 115,

[0040] Permanent magnet 120. DETAILED DESCRIPTION

[0041] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0042] In the description of the present invention, it should be understood that the terms "center", "width", "inside", "outside", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0043] Reference below Figure 1-Figure 4 The specific structure of the rotor 100 of the permanent magnet motor according to the embodiment of the present invention is described.

[0044] like Figure 1-Figure 3 As shown, the rotor 100 of the permanent magnet motor according to an embodiment of the present invention includes a rotor core 110 and a plurality of permanent magnets 120. The rotor core 110 has a center hole 115 and a plurality of magnet slots 111. The plurality of magnet slots 111 are arranged circumferentially of the center hole 115. Each magnet slot 111 extends in a radial direction of the center hole 115. The plurality of permanent magnets 120 are inserted into the plurality of magnet slots 111 in a one-to-one correspondence. At least one first magnetic isolation slot 112 is formed at the radial ends of each permanent magnet 120 at each magnet slot 111.

[0045] Among them, the rotor core 110 is provided with a second magnetic isolation groove 113 on at least one side of each magnet slot 111 in the circumferential direction. The second magnetic isolation groove 113 divides the single-sided area where it is located into a plurality of magnetic field paths 114 distributed radially. The single-sided area is the area between the circumferential edge of the center hole 115 and the outer circumferential edge of the rotor core 110 corresponding to the second magnetic isolation groove 113. In at least one group of two radially adjacent magnetic field paths 114, the minimum width of the magnetic field path 114 located on the radial outer side is smaller than the minimum width of the magnetic field path 114 located on the radial inner side.

[0046] It should be noted that, since each magnet slot 111 extends along the radial direction of the center hole 115 , that is to say, the rotor 100 of the present invention is a tangential flux rotor 100 .

[0047] It can be understood that, assuming that a second magnetic isolation groove 113 is provided on one circumferential side of each magnet slot 111 of the rotor core 110, the second magnetic isolation groove 113 divides the area corresponding to the circumference of the center hole 115 where the second magnetic isolation groove 113 is located and the outer circumferential edge of the rotor core 110 into two magnetic field paths 114, and the minimum width of the magnetic field path 114 on the radial outer side of the two magnetic field paths 114 is smaller than the minimum width of the magnetic field path 114 on the radial inner side. Such a structure can make the outer periphery of the rotor core 110 magnetized and saturated first, which is conducive to the magnetization magnetic field from the outer periphery of the rotor core 110 to the inner periphery of the rotor 100 for magnetization, thereby ensuring the magnetization of the rotor core 110 near one end of the permanent magnet 120 close to the center hole 115, and improving the magnetization characteristics of the rotor core 110.

[0048] In addition, the rotor 100 of the present invention can also improve the air gap flux density of the permanent magnet motor 10, such as Figure 4 As shown, the air gap flux density of the permanent magnet motor of the prior art is a square wave with pits, and has a large harmonic content, which will cause the problem of high noise of the motor. The permanent magnet motor 10 of the present invention has a significantly improved air gap flux density waveform and reduced harmonic content, thereby improving the noise of the permanent magnet motor 10.

[0049] It should be further explained that the area between the circumference of the center hole 115 and the outer circumference of the rotor core 110 corresponding to the second magnetic isolation groove 113 refers to the area surrounded by the axis of the center hole 115, the outer circumference of the rotor core 110 and the tangents passing through the two outermost points of the second magnetic isolation groove 113 in the circumferential direction. It should be further emphasized that the area between the circumference of the center hole 115 and the outer circumference of the rotor core 110 that is not blocked by the second magnetic isolation groove 113 cannot be called a single-sided area.

[0050] In addition, the minimum width of the magnetic field path 114 refers to the distance between the radially outermost point of the second magnetic isolation groove 113 and the outer peripheral edge of the rotor core 110, or the distance between the radially innermost point of the second magnetic isolation groove 113 and the peripheral edge of the center hole 115. Alternatively, when there are multiple second magnetic isolation grooves 113, the minimum width of the magnetic field path 114 is the distance between the radially outermost point of the second magnetic isolation groove 113 and the second magnetic isolation groove 113 adjacent to the radial outer side, or the distance between the radially innermost point of the second magnetic isolation groove 113 and the second magnetic isolation groove 113 adjacent to the radial inner side.

[0051] According to the rotor 100 of the permanent magnet motor of the embodiment of the present invention, since the rotor core 110 is provided with a second magnetic isolation groove 113 on at least one side of each magnet slot 111 in the circumferential direction, the second magnetic isolation groove 113 divides the single-side area into a plurality of magnetic field paths 114 distributed radially, and among two adjacent magnetic field paths 114 in the radial direction, the minimum width of the magnetic field path 114 located on the radial outer side is smaller than the minimum width of the magnetic field path 114 located on the radial inner side, which is conducive to the magnetization magnetic field from the outer periphery of the rotor core 110 to penetrate into the inner periphery of the rotor 100 for magnetization, thereby ensuring the magnetization of the rotor core 110 near one end of the permanent magnet 120 close to the center hole 115, improving the magnetization characteristics of the rotor core 110, and in addition, it can also improve the air gap magnetic density waveform of the permanent magnet motor 10, reduce the harmonic content, and thus improve the noise of the permanent magnet motor 10.

[0052] In some embodiments, Figure 1-Figure 3 As shown, a plurality of second magnetic isolation grooves 113 are provided on both circumferential sides of each magnet slot 111, and the plurality of second magnetic isolation grooves 113 located on one circumferential side of each magnet slot 111 are spaced apart in the radial direction. Thus, the air gap magnetic flux density of the permanent magnet motor 10 can be further improved, thereby reducing the noise of the permanent magnet motor 10.

[0053] In some specific embodiments, the cross section of each second magnetic isolation slot 113 is formed as a parallelogram, and the sides of the second magnetic isolation slots 113 on the circumferential side of each magnet slot 111 are coplanar, and the sides of each second magnetic isolation slot 113 on the circumferential side are parallel to the magnet slot 111. In this way, the air gap magnetic density of the permanent magnet motor 10 can be further improved, thereby reducing the low noise of the permanent magnet motor 10.

[0054] In some more specific embodiments, Figure 1-Figure 3 As shown, the angle between the second magnetic isolation slot 113 and the magnet slot 111 toward the outer circumference of the rotor core 110 is an acute angle, and the multiple acute angles formed in the multiple second magnetic isolation slots 113 on one circumferential side of each magnet slot 111 gradually increase from the inside to the outside. In this way, the air gap magnetic density of the permanent magnet motor 10 can be further improved, thereby reducing the low noise of the permanent magnet motor 10.

[0055] It should be noted that the second magnetic isolation groove 113 is not limited to a parallelogram shape, but may also be a circle, a triangle, an irregular shape or other shapes.

[0056] In some embodiments, Figure 1-Figure 2 As shown, a magnetic bridge is provided between the second magnetic isolation slot 113 and the adjacent magnet slot 111. The magnetic bridge provided between the second magnetic isolation slot 113 and the magnet slot 111 can ensure the air gap magnetic density of the permanent magnet motor 10 and improve the magnetic flux utilization rate of the permanent magnet 120.

[0057] In some embodiments, Figure 3 As shown, the second magnetic isolation slot 113 is connected to the adjacent magnet slot 111. Thus, the manufacture of the rotor core 110 can be facilitated.

[0058] In some embodiments, Figure 1-Figure 3 As shown, the first magnetic isolation groove 112 located on the radial inner side of the permanent magnet 120 has a long strip protrusion 1121 protruding radially outward on the inner wall facing the center of the rotor core 110. Since the central hole 115 is provided on the radial inner side of the permanent magnet 120, the long strip protrusion 1121 protruding radially outward on the inner wall of the first magnetic isolation groove 112 facing the center of the rotor core 110 can improve the strength of the magnetic bridge between the first magnetic isolation groove 112 and the central hole 115, thereby avoiding the phenomenon of the magnetic bridge breaking when the rotor 100 rotates. It should be noted that the role of the long strip protrusion 1121 is to increase the strength. Therefore, the shape of the protrusion 1121 is not limited to a long strip, but can also be any other shape.

[0059] In some embodiments, the permanent magnet 120 is a rare earth permanent magnet 120 or a ferrite permanent magnet 120 .

[0060] Example:

[0061] Reference below Figure 1-Figure 2 A rotor 100 of a permanent magnet motor according to a specific embodiment of the present invention is described.

[0062] like Figure 1 As shown, the rotor 100 of the permanent magnet motor of this embodiment includes a rotor core 110 and ten permanent magnets 120. The rotor core 110 has a center hole 115 and ten magnet slots 111. The ten magnet slots 111 are arranged along the circumference of the center hole 115. Each magnet slot 111 extends along the radial direction of the center hole 115. The ten permanent magnets 120 are inserted into the plurality of magnet slots 111 in a one-to-one correspondence. The parts of each magnet slot 111 located at the radial ends of each permanent magnet 120 form a first magnetic isolation slot 112. The first magnetic isolation slot 112 located on the radial inner side of the permanent magnet 120 has a long strip protrusion 1121 protruding radially outward on its inner wall facing the center of the rotor core 110.

[0063] The rotor core 110 is provided with two second magnetic isolation grooves 113 on both sides of each magnet slot 111 in the circumferential direction. The two second magnetic isolation grooves 113 divide the single-side area where they are located into three magnetic field paths 114 distributed in the radial direction. The single-side area is the area between the circumference of the center hole 115 and the outer circumference of the rotor core 110 corresponding to the second magnetic isolation grooves 113. Among the two adjacent magnetic field paths 114 in the radial direction, the minimum width of the magnetic field path 114 located on the radial outer side is smaller than the minimum width of the magnetic field path 114 located on the radial inner side. The cross section of each second magnetic isolation groove 113 is formed as a parallelogram. Among the multiple second magnetic isolation grooves 113 on one side of each magnet slot 111 in the circumferential direction, the side edges of the multiple second magnetic isolation grooves 113 on both sides in the circumferential direction are respectively coplanar, and the side edges of each second magnetic isolation groove 113 on both sides in the circumferential direction are parallel to the magnet slot 111. The included angle between the second magnetic isolation groove 113 and the magnet groove 111 toward the outer circumference of the rotor core 110 is an acute angle. In the two second magnetic isolation grooves 113 on one circumferential side of each magnet groove 111, the acute angle on the radial outer side is greater than the acute angle on the radial inner side.

[0064] Taking the second magnetic isolation groove 113 located on the radial outer side as an example, the magnetic field path 114 between it and the outer peripheral edge of the rotor core 110 is called the outer magnetic field path 114b, and the magnetic field path 114 between the other second magnetic isolation grooves 113 is called the inner magnetic field path 114a. Figure 2 As shown, the depth of the shaded portion of the magnetic field path 114 represents the degree of saturation. Figure 2 It can be seen that the outer magnetic field path 114b is more saturated than the inner magnetic field path 114a, thereby limiting the magnetizing magnetic lines of force from passing through the outer magnetic field path 114b close to the outer periphery of the rotor core 110, and more magnetic lines of force enter the inner magnetic field path 114a or the magnetic field path 114 closer to the center hole 115, thereby making the part of the permanent magnet 120 close to the center hole 115 magnetized and saturated, which improves the magnetizing characteristics of the permanent magnet motor 10 to a certain extent.

[0065] like Figure 5 As shown, the permanent magnet motor 10 according to the embodiment of the present invention includes the rotor 100 of the permanent magnet motor mentioned above.

[0066] The permanent magnet motor 10 according to the embodiment of the present invention has the permanent magnet motor rotor 100 as described above, so the working noise of the permanent magnet motor 10 is reduced and the working efficiency of the permanent magnet motor 10 is improved.

[0067] like Figure 6 As shown, the compressor 1 according to the embodiment of the present invention includes a permanent magnet motor 10.

[0068] The permanent magnet motor 10 according to the embodiment of the present invention reduces the working noise of the compressor 1 and improves the working efficiency of the compressor 1 due to the permanent magnet motor 10 described above.

[0069] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0070] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A rotor of a permanent magnet motor, characterized in that: include: A rotor core, the rotor core having a central hole and a plurality of magnet slots, the plurality of magnet slots being arranged along the circumference of the central hole, and each of the magnet slots extending along the radial direction of the central hole; A plurality of permanent magnets, wherein the plurality of permanent magnets are inserted into the plurality of magnet slots in a one-to-one correspondence, and each of the magnet slots is located at two radial ends of each of the permanent magnets to form at least one first magnetic isolation slot; The rotor core is provided with a second magnetic isolation groove on at least one side of each magnet slot in the circumferential direction, and the second magnetic isolation groove divides the single-side area where it is located into a plurality of magnetic field paths distributed in the radial direction, and the single-side area is the area between the circumference of the center hole and the outer circumference of the rotor core corresponding to the second magnetic isolation groove, and in at least one group of two radially adjacent magnetic field paths, the minimum width of the magnetic field path located on the radially outer side is smaller than the minimum width of the magnetic field path located on the radially inner side; A plurality of the second magnetic isolation grooves are provided on both sides of each magnet groove in the circumferential direction, and the plurality of the second magnetic isolation grooves located on one side of each magnet groove in the circumferential direction are spaced apart and distributed in the radial direction; In the plurality of second magnetic isolation grooves on one circumferential side of each magnet groove, the circumferential sides of the plurality of second magnetic isolation grooves are coplanar, and the circumferential sides of each second magnetic isolation groove are parallel to the magnet groove.

2. The rotor of the permanent magnet motor according to claim 1, characterized in that: The cross section of each of the second magnetic isolation grooves is formed into a parallelogram.

3. The rotor of the permanent magnet motor according to claim 2, characterized in that: An included angle between the second magnetic isolation groove and the magnet groove toward the outer peripheral edge of the rotor core is an acute angle.

4. The rotor of the permanent magnet motor according to claim 1, characterized in that: A magnetic bridge is provided between the second magnetic isolation groove and the adjacent magnet groove.

5. The rotor of the permanent magnet motor according to claim 1, characterized in that: The second magnetic isolation groove is communicated with the adjacent magnet groove.

6. The rotor of the permanent magnet motor according to claim 1, characterized in that: The first magnetic isolation groove located radially inside the permanent magnet has a long strip-shaped protrusion protruding radially outward on its inner wall facing the center of the rotor core.

7. The rotor of the permanent magnet motor according to any one of claims 1 to 6, characterized in that: The permanent magnet is a rare earth permanent magnet or a ferrite permanent magnet.

8. A permanent magnet motor, characterized in that: A rotor comprising a permanent magnet motor according to any one of claims 1-7.

9. A compressor, characterized in that: Comprising the permanent magnet motor according to claim 8.

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