Rotor structure, motor and compressor

Abstract

The main purpose of the present invention is to provide a rotor structure, a motor and a compressor, wherein the rotor structure includes a rotor core and a plurality of permanent magnets arranged on the rotor core to form a plurality of magnetic poles on the rotor core, wherein the plurality of magnetic poles include a plurality of N poles and a plurality of S poles arranged alternately along the circumference of the rotor core; a magnetic isolation hole is provided on at least one magnetic pole of the rotor core, and the magnetic isolation hole includes a main hole body, a first branch hole and a second branch hole that are interconnected; wherein the plane perpendicular to the axis of the rotor core is taken as the predetermined plane, the projection of the main hole body on the predetermined plane is a bar and its extension direction is arranged crosswise with the circumference of the rotor core, and the projection of the first branch hole and the second branch hole on the predetermined plane is located on the same side of the main hole body. Through the above-mentioned arrangement of the present invention, the problem of large vibration noise of the motor in the prior art is solved.

Description

Technical Field

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

[0002] In recent years, with the development of permanent magnet material manufacturing technology and the rapid decline in costs, its excellent performance and low price have greatly promoted the development of permanent magnet motor technology. The abundant resources of permanent magnet materials have promoted the research and development of permanent magnet motor technology.

[0003] Permanent magnet motors generate main magnetic fields with permanent magnets. Compared with ordinary induction motors, permanent magnet synchronous motors do not require reactive excitation current, and the rotor resistance loss is zero in synchronous operation. Therefore, it has the characteristics of high power factor and high efficiency, and can usually be used to replace induction motors with lower power indexes. Its economic and social benefits are very significant, and it is widely used in all walks of life.

[0004] However, the permanent magnet material of the permanent magnet synchronous motor has a fixed brand and material, and its magnetic energy product remains unchanged, making it difficult to adjust the air gap magnetic field of the motor. At the same time, the tooth structure of the motor makes the air gap magnetic density and back electromotive force have a large harmonic content, and the peak value of the electromagnetic force density of the motor is large, resulting in large torque pulsation and vibration noise of the motor. Summary of the invention

[0005] The main purpose of the present invention is to provide a rotor structure, a motor and a compressor to solve the problem of high vibration noise of the motor in the prior art.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a rotor structure is provided, comprising a rotor core and a plurality of permanent magnets arranged on the rotor core to form a plurality of magnetic poles on the rotor core, the plurality of magnetic poles comprising a plurality of N poles and a plurality of S poles alternately arranged along the circumference of the rotor core; a magnetic isolation hole is opened on at least one magnetic pole of the rotor core, the magnetic isolation hole comprises a main hole body, a first branch hole and a second branch hole which are interconnected; wherein, a plane perpendicular to the axis of the rotor core is taken as a predetermined plane, a projection of the main hole body on the predetermined plane is a bar and its extension direction is arranged crosswise with the circumference of the rotor core, and the projections of the first branch hole and the second branch hole on the predetermined plane are located on the same side of the main hole body.

[0007] Further, the projection of the main hole body on the predetermined plane extends along the radial direction of the rotor core; or the extension direction of the projection of the main hole body on the predetermined plane is parallel to the magnetic pole center line of the corresponding magnetic pole.

[0008] Further, the extension direction of the projections of the first branch hole and the second branch hole on the predetermined plane is perpendicular to the extension direction of the main hole body on the predetermined plane; or, the extension direction of the projections of the first branch hole and the second branch hole on the predetermined plane extends along the circumference of the rotor core.

[0009] Furthermore, the projection of the first branch hole on the predetermined plane is a strip with a length of A, and the maximum width of the projection of the main hole body on the predetermined plane is B; wherein, 4≥A / B≥1.3.

[0010] Furthermore, the first branch hole and the second branch hole are arranged in a direction close to the axis of the rotor core; the minimum distance between the second branch hole and the permanent magnet on one side of the corresponding magnetic pole is D, and the projection of the second branch hole on the predetermined plane is a bar with a minimum width of C; wherein 3≥C / D≥0.8.

[0011] Each magnetic pole includes a plurality of magnetic isolation holes, and the plurality of magnetic isolation holes are arranged in pairs; the two magnetic isolation holes in a pair are symmetrically arranged relative to the magnetic pole center line of the corresponding magnetic pole; and / or the free ends of the first branch hole and the second branch hole of each magnetic isolation hole extend in a direction away from or close to the magnetic pole center line; and / or the first branch hole and the second branch hole are arranged in a direction close to the axis of the rotor core; the two magnetic isolation holes in a pair are arranged in parallel and the distance between them is F, the minimum distance between the second branch hole and the permanent magnet on one side of the corresponding magnetic pole is D, the projection of the second branch hole on the predetermined plane is a bar with a minimum width of C, and the thickness of the permanent magnet is E; wherein, 2.5≥(C+E) / (D+F)≥0.3.

[0012] Furthermore, the first branch hole and the second branch hole are arranged along the direction close to the axis of the rotor core; the projection of the first branch hole on the predetermined plane is a bar with a width of H, the projection of the second branch hole on the predetermined plane is a bar with a width of G, and the total length of the magnetic isolation hole along the extension direction of the first branch hole is J; wherein, 0.8≥(G+H) / J≥0.3.

[0013] Furthermore, the first branch hole and the second branch hole are arranged along the direction close to the axis of the rotor core; the length of the projection of the first branch hole on the predetermined plane is A, and the length of the projection of the second branch hole on the predetermined plane is C; wherein, 3.1≥C / A≥1.2.

[0014] Furthermore, the first branch hole and the second branch hole are arranged along the direction close to the axis of the rotor core; a magnetic isolation bridge is formed between the first branch hole and the outer peripheral surface of the rotor core; along the circumference of the rotor core, the width of the magnetic isolation bridge along the radial direction of the rotor core is consistent; and / or the width of the magnetic isolation bridge along the radial direction of the rotor core is L, and the width of the motor air gap of the motor formed by the rotor structure is δ; wherein, 1.5≥L / δ≥0.5.

[0015] Furthermore, the magnetic isolation hole has a first end and a second end arranged in a direction close to the axis of the rotor core, and the magnetic isolation hole gradually moves away from the magnetic pole center line of the corresponding magnetic pole from the first end to the second end; or the magnetic isolation hole gradually approaches the magnetic pole center line of the corresponding magnetic pole from the first end to the second end.

[0016] Furthermore, the side wall of the magnetic isolation hole close to the magnetic pole center line of the corresponding magnetic pole is inclined relative to the magnetic pole center line; each magnetic pole includes multiple magnetic isolation holes, and the multiple magnetic isolation holes are arranged in pairs; the minimum distance between two paired magnetic isolation holes is O, and the maximum distance between two paired magnetic isolation holes is P; 0.9≥O / P≥0.3.

[0017] According to a second aspect of the present invention, a motor is provided, comprising a stator structure and a rotor structure, wherein the rotor structure is the above-mentioned rotor structure.

[0018] According to a third aspect of the present invention, a compressor is provided, comprising a motor, which is the motor described above.

[0019] By applying the technical solution of the present invention, a rotor structure having a rotor core, a plurality of permanent magnets and a magnetic isolation hole is provided, wherein the plurality of permanent magnets are evenly distributed on the rotor core around the axis of the rotor core to form a plurality of magnetic poles, including an N pole and an S pole; a magnetic isolation hole is provided on at least one magnetic pole, and the magnetic isolation hole includes a main hole body (i.e., a main trunk of the magnetic isolation hole), a first branch hole and a second branch hole (i.e., a branch extending from the main trunk of the magnetic isolation hole) that are interconnected; a plane perpendicular to the axis of the rotor core is taken as a predetermined plane, and the projection of the main hole body on the predetermined plane is in the shape of a strip (i.e., the projection of the main hole body in the direction perpendicular to the axis of the rotor core) The cross section is a bar shape and its extension direction is intersected with the circumference of the rotor core. The projections of the first branch hole and the second branch hole on the predetermined plane are bar-shaped. The first branch hole and the second branch hole are intersected with the projections of the main hole body on the predetermined plane and are located on the same side of the main hole body, which makes the width of the magnetic isolation hole have a gradient change, that is, on the cross section of the magnetic isolation hole perpendicular to the axial direction of the rotor core, the dimensions of the cross section along the radial and circumferential directions of the rotor core are gradient-changed, and along the axial direction of the rotor core, the size and shape of the cross section of the magnetic isolation hole perpendicular to the axial direction of the rotor core are unchanged. Through the technical solution provided by the present invention, the magnetic resistance distribution at various places of the motor magnetic circuit is effectively improved, the magnetic flux direction is improved, the air gap magnetic field distribution is adjusted, the air gap magnetic density waveform is improved, the motor cogging effect is reduced, the proportion of back-EMF harmonics of the motor is reduced, the torque pulsation of the motor is reduced, the peak value of the electromagnetic force density of the motor is reduced, and the electromagnetic vibration noise of the motor is reduced, which solves the problem of large vibration noise of the motor in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 A schematic structural diagram of a rotor structure according to a first embodiment of the present invention is shown;

[0022] Figure 2 Shows Figure 1 A schematic diagram of the magnetic flux direction of the rotor structure shown;

[0023] Figure 3 A schematic structural diagram of a rotor structure according to a second embodiment of the present invention is shown;

[0024] Figure 4 A schematic structural diagram of a rotor structure according to a third embodiment of the present invention is shown;

[0025] Figure 5 shows a schematic structural diagram of a rotor structure according to a fourth embodiment of the present invention;

[0026] Figure 6 shows a schematic structural diagram of a rotor structure according to a fifth embodiment of the present invention;

[0027] Figure 7 shows a schematic structural diagram of a rotor structure according to a sixth embodiment of the present invention;

[0028] Figure 8 A comparison diagram of the measured torque pulsation of the existing motor and the motor of the present application is shown;

[0029] Fig. 9 A comparison diagram of the measured proportion of back-EMF harmonics of the prior art motor and the motor of the present application is shown;

[0030] Fig.10 A comparison diagram showing the measured peak values ​​of electromagnetic force density of the prior art motor and the motor of the present application is shown; and

[0031] Fig.11 A comparison chart of the measured total noise values ​​of a compressor having a conventional motor and a compressor having the motor of the present application is shown.

[0032] The above drawings include the following reference numerals:

[0033] 1. Rotor core; 2. Permanent magnet; 3. Magnetic pole; 31. Magnetic pole center line; 4. Magnetic isolation hole; 41. Main hole body; 42. First branch hole; 43. Second branch hole; 5. Magnetic isolation bridge. DETAILED DESCRIPTION

[0034] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0035] like Figures 1 to 11 As shown, the present invention provides a rotor structure, including a rotor core 1 and a plurality of permanent magnets 2 arranged on the rotor core 1, so as to form a plurality of magnetic poles 3 on the rotor core 1, wherein the plurality of magnetic poles 3 include a plurality of N poles and a plurality of S poles alternately arranged along the circumference of the rotor core 1; a magnetic isolation hole 4 is opened on at least one magnetic pole 3 of the rotor core 1, and the magnetic isolation hole 4 includes a main hole body 41, a first branch hole 42 and a second branch hole 43 which are interconnected; wherein, a plane perpendicular to the axis of the rotor core 1 is taken as a predetermined plane, a projection of the main hole body 41 on the predetermined plane is in a strip shape and its extension direction is arranged to cross the circumference of the rotor core 1, and the projections of the first branch hole 42 and the second branch hole 43 on the predetermined plane are located on the same side of the main hole body 41.

[0036] By applying the technical solution of the present invention, a rotor structure is provided, which includes a rotor core 1, a plurality of permanent magnets 2 and a magnetic isolation hole 4, wherein the plurality of permanent magnets 2 are evenly distributed on the rotor core 1 around the axis of the rotor core 1 to form a plurality of magnetic poles 3, including an N pole and an S pole; at least one magnetic pole 3 is provided with a magnetic isolation hole 4, and the magnetic isolation hole 4 includes a main hole body 41 (i.e., a main stem of the magnetic isolation hole 4), a first branch hole 42 and a second branch hole 43 (i.e., a branch extending from the main stem of the magnetic isolation hole 4) that are interconnected; a plane perpendicular to the axis of the rotor core 1 is taken as a predetermined plane, and the projection of the main hole body 41 on the predetermined plane is a strip shape (i.e., the projection of the main hole body 41 on the plane perpendicular to the axis of the rotor core 1 is a strip shape). The cross section of the first branch hole 42 and the second branch hole 43 is bar-shaped and its extension direction is cross-arranged with the circumferential direction of the rotor core 1. The projections of the first branch hole 42 and the second branch hole 43 on the predetermined plane are bar-shaped. The first branch hole 42 and the second branch hole 43 are cross-arranged with the projection of the main hole body 41 on the predetermined plane and are located on the same side of the main hole body 41, which makes the width of the magnetic isolation hole 4 have a gradient change, that is, on the cross section of the magnetic isolation hole 4 perpendicular to the axial direction of the rotor core 1, the dimensions of the cross section along the radial and circumferential directions of the rotor core 1 are gradient-changed, and along the axial direction of the rotor core 1, the size and shape of the cross section of the magnetic isolation hole 4 perpendicular to the axial direction of the rotor core 1 are unchanged. Through the technical solution provided by the present invention, the magnetic resistance distribution at various parts of the motor magnetic circuit is effectively improved, the direction of the magnetic flux is improved, the air gap magnetic field distribution is adjusted, the air gap magnetic density waveform is improved, the cogging effect of the motor is reduced, the proportion of back-electromotive force harmonics of the motor is reduced, the torque pulsation of the motor is reduced, the peak value of the electromagnetic force density of the motor is reduced, and the electromagnetic vibration noise of the motor is reduced, thereby solving the problem of large vibration noise of the motor in the prior art.

[0037] Specifically, the rotor core 1 is made of a material with strong magnetic conductivity, which makes the magnetic resistance of the rotor core 1 small. Optionally, the rotor core 1 is formed by stacking a plurality of silicon steel sheets, which makes it easy for magnetic lines of force to pass through. Since the magnetic isolation hole 4 is filled with non-magnetic materials such as air, the magnetic conductivity is poor, the magnetic resistance is large, and the magnetic lines of force are not easy to pass through, by opening such a magnetic isolation hole 4, the magnetic resistance distribution of various parts of the magnetic circuit of the motor rotor structure can be changed, the direction of the magnetic lines of force in the rotor structure can be changed, and the air gap magnetic density waveform can be improved, thereby reducing the proportion of back-electromotive force harmonics, reducing motor torque pulsation, reducing the amplitude of electromagnetic force, and reducing the electromagnetic vibration noise of the motor.

[0038] like Figure 2 The figure is a schematic diagram of the magnetic flux direction of the rotor structure of the embodiment provided by the present invention. The lines with arrows are the marks of magnetic lines of force. The solid lines with arrows indicate that more magnetic lines of force pass through the position, and the dotted lines with arrows indicate that fewer magnetic lines of force pass through the position. Figure 2 It can be clearly seen that at the location where the magnetic isolation holes 4 are located, fewer magnetic lines of force pass through. The magnetic isolation holes 4 provided by the present invention effectively improve the distribution of magnetic lines of force of the rotor structure.

[0039] exist Figures 1 to 7 In the illustrated embodiment, the projection of the main hole body 41 on the predetermined plane extends in the radial direction of the rotor core 1 ; or the extension direction of the projection of the main hole body 41 on the predetermined plane is parallel to the magnetic pole center line 31 of the corresponding magnetic pole 3 .

[0040] exist Figures 1 to 7 In the illustrated embodiment, the extension direction of the projections of the first branch hole 42 and the second branch hole 43 on the predetermined plane is perpendicular to the extension direction of the main hole body 41 on the predetermined plane; or, the extension direction of the projections of the first branch hole 42 and the second branch hole 43 on the predetermined plane extends along the circumferential direction of the rotor core 1.

[0041] Specifically, the rotor structure provided by the present invention adopts the magnetic isolation hole 4 with an inverted "concave" shaped structure. The magnetic isolation hole 4 has a main hole body 41 extending in the radial direction of the rotor core 1, that is, the middle part of the magnetic isolation hole 4, and a first branch hole 42 and a second branch hole 43 extending in the circumferential direction of the rotor, that is, the branch parts extending from the main body of the magnetic isolation hole 4. The main hole body 41 has a first end and a second end located in the radial direction of the rotor core 1, the first end is arranged near the axis of the rotor core 1, and the second end is arranged near the outer peripheral surface of the rotor core 1.

[0042] In the magnetic isolation hole 4, the first branch hole 42 is arranged at the first end of the main hole body 41, and the second branch hole 43 is arranged at the second end of the main hole body 41, and the first branch hole 42 and the second branch hole 43 are both arranged on the same side of the extension direction of the main hole body 41, so that the shape of the magnetic isolation hole 4 is an inverted "concave" structure that is wide at both ends and narrow in the middle along the radial direction of the rotor core 1, and the width of the magnetic isolation hole 4 along the radial direction and circumferential direction of the rotor core 1 has a gradient change.

[0043] like Figures 1 to 6 As shown, the first branch hole 42 and the second branch hole 43 both extend from the main hole 41 toward the permanent magnet 2 located on the same side of the two branch holes. In this way, the magnetic flux direction of the permanent magnet 2 in the rotor core 1 can be improved, thereby improving the magnetic field distribution at the air gap of the motor and improving the air gap magnetic flux waveform, so as to reduce the torque pulsation of the motor, reduce the proportion of back-electromotive force harmonics of the motor, and reduce the peak electromagnetic force density and electromagnetic vibration noise of the motor.

[0044] Preferably, Figure 7 As shown, in the magnetic isolation hole 4 of the inverted "concave" shaped structure, the first branch hole 42 and the second branch hole 43 both extend from the main hole body 41 toward the magnetic pole center line 31, so that the magnetic bridge width in the middle of the magnetic pole 3 (that is, the distance between two magnetic isolation holes 4 symmetrical about the magnetic pole center line 31 on a magnetic pole 3) changes from "narrow-wide-narrow", the magnetic flux density at the wide position is low, and the magnetic flux density at the narrow position is high. At the same time, a small part of the magnetic flux at the wide position will pass through the branch holes and be transmitted to the air gap, so that the sinusoidality of the magnetic density waveform at the air gap is better, further reducing the proportion of back-electromotive force harmonics, reducing the peak value of the electromagnetic force density, and thus reducing the vibration noise of the motor.

[0045] like Figure 1 As shown, the projection of the first branch hole 42 on the predetermined plane is a strip with a length of A, and the maximum width of the projection of the main hole body 41 on the predetermined plane is B; wherein, 4≥A / B≥1.3.

[0046] The length A of the projection of the first branch hole 42 on the predetermined plane is its width in the circumferential direction of the rotor core 1 ; the maximum width B of the projection of the main hole body 41 on the predetermined plane is its width in the circumferential direction of the rotor core 1 .

[0047] Since the first branch hole 42 is close to the outer circumferential surface of the rotor core 1, the width A of the first branch hole 42 in the circumferential direction of the rotor core 1 is greater than the width B of the main hole body 41 in the circumferential direction of the rotor core 1, so that the magnetic resistance of the first branch hole 42 in the radial direction of the rotor core 1 can be smaller than the magnetic resistance of the main hole body 41 in the radial direction of the rotor core 1. When the value of A / B is set within the range of 1.3 to 4, the circumferential magnetic resistance distribution of the rotor core 1 can be effectively improved, the air gap magnetic flux waveform can be further improved, and the peak value of the electromagnetic force density of the motor can be reduced.

[0048] like Figure 1 As shown, the first branch hole 42 and the second branch hole 43 are arranged along the direction close to the axis of the rotor core 1; the minimum distance between the second branch hole 43 and the permanent magnet 2 on one side of the corresponding magnetic pole 3 is D, and the projection of the second branch hole 43 on the predetermined plane is a bar with a minimum width of C; wherein 3≥C / D≥0.8.

[0049] The minimum width C of the projection of the second branch hole 43 on the predetermined plane is the width thereof in the circumferential direction of the rotor core 1 .

[0050] The minimum distance D between the second branch hole 43 and the permanent magnet 2 on one side of the corresponding magnetic pole 3 cannot be zero, and the distance is required for the conduction of the magnetic flux of the permanent magnet 2. When the value of C / D is set within the range of 0.8 to 3, the sinusoidality of the air gap magnetic field waveform can be effectively improved without reducing the output torque of the motor, and the peak value of the electromagnetic force density and the electromagnetic vibration noise of the motor can be reduced.

[0051] like Figure 1 As shown, each magnetic pole 3 includes a plurality of magnetic isolation holes 4, and the plurality of magnetic isolation holes 4 are arranged in pairs; the two magnetic isolation holes 4 in a pair are symmetrically arranged relative to the magnetic pole center line 31 of the corresponding magnetic pole 3; and / or the free ends of the first branch hole 42 and the second branch hole 43 of each magnetic isolation hole 4 extend in a direction away from or close to the magnetic pole center line 31; and / or the first branch hole 42 and the second branch hole 43 are arranged in a direction close to the axis of the rotor core 1; the two magnetic isolation holes 4 in a pair are arranged in parallel and the distance between them is F, the minimum distance between the second branch hole 43 and the permanent magnet 2 on one side of the corresponding magnetic pole 3 is D, the projection of the second branch hole 43 on the predetermined plane is a bar with a minimum width of C, and the thickness of the permanent magnet 2 is E; wherein, 2.5≥(C+E) / (D+F)≥0.3.

[0052] The minimum width C of the projection of the second branch hole 43 on the predetermined plane is the width thereof in the circumferential direction of the rotor core 1; each magnetic pole 3 has at least two magnetic isolation holes 4 with an inverted "concave" shape structure, and the distance between the two magnetic isolation holes 4 is F. When the value of (C+E) / (D+F) is set within the range of 0.3 to 2.5, the effective output of the magnetic flux of the permanent magnet 2 is ensured, and at the same time, when the magnetic flux passes through the magnetic isolation holes 4 with an inverted "concave" shape structure, the magnetic flux at various locations on the outer circumferential surface of the rotor core 1 is not equal, which further improves the sinusoidality of the air gap magnetic density waveform, and at the same time reduces the proportion of back-electromotive force harmonics of the motor, reduces the electromagnetic vibration noise of the motor, reduces harmonic losses, and improves the motor efficiency.

[0053] like Figure 1As shown, the first branch hole 42 and the second branch hole 43 are arranged along the direction close to the axis of the rotor core 1; the projection of the first branch hole 42 on the predetermined plane is a bar with a width of H, the projection of the second branch hole 43 on the predetermined plane is a bar with a width of G, and the total length of the magnetic isolation hole 4 along the extension direction of the first branch hole 42 is J; wherein, 0.8≥(G+H) / J≥0.3.

[0054] The widths H and G of the projections of the first branch hole 42 and the second branch hole 43 on the predetermined plane are their lengths in the radial direction of the rotor core 1; the total length J of the magnetic isolation hole 4 along the extension direction of the first branch hole 42 is the length of the main hole body 41 in the radial direction of the rotor core 1. The lengths of the first branch hole 42 and the second branch hole 43 in the radial direction of the rotor core 1 determine the radial magnetic resistance distribution at various locations on the circumference of the rotor core 1. When the value of (G+H) / J is set within the range of 0.3 to 0.8, the magnetic permeance distribution of the magnetic circuit of the rotor core 1 is more uniform, the air gap harmonics are reduced, the peak value of the electromagnetic force density of the motor is reduced, and the electromagnetic vibration noise of the motor is reduced.

[0055] like Figure 3 As shown, the first branch hole 42 and the second branch hole 43 are arranged along the direction close to the axis of the rotor core 1; the length of the projection of the first branch hole 42 on the predetermined plane is A, and the length of the projection of the second branch hole 43 on the predetermined plane is C; wherein, 3.1≥C / A≥1.2.

[0056] The lengths A and C of the projections of the first branch hole 42 and the second branch hole 43 on the predetermined plane are the widths thereof in the circumferential direction of the rotor core 1 .

[0057] The relationship between the widths A and C of the first branch hole 42 and the second branch hole 43 in the circumferential direction of the rotor core 1 can be set in such a way that the second branch hole 43 is closer to the side of the permanent magnet 2 close to the axis of the rotor core 1, effectively improving the magnetic flux transmitted by the permanent magnet 2 to both sides of the second branch hole 43. When the value of C / A is set within the range of 1.2 to 3.1, the magnetic field waveform at the air gap can be effectively improved, the torque pulsation of the motor can be reduced, the peak value of the electromagnetic force density of the motor can be reduced, and the electromagnetic vibration noise of the motor can be reduced.

[0058] like Figure 4 As shown, the first branch hole 42 and the second branch hole 43 are arranged along the direction close to the axis of the rotor core 1; a magnetic isolation bridge 5 is formed between the first branch hole 42 and the outer peripheral surface of the rotor core 1; along the circumference of the rotor core 1, the width of the magnetic isolation bridge 5 along the radial direction of the rotor core 1 is consistent; and / or the width of the magnetic isolation bridge 5 along the radial direction of the rotor core 1 is L, and the width of the motor air gap of the motor formed by the rotor structure is δ; wherein, 1.5≥L / δ≥0.5.

[0059] The width δ of the motor air gap of the motor formed by the rotor structure is the gap between the rotor and the stator of the motor, and the air gap magnetic flux density refers to the magnetic induction intensity of the magnetic field existing in the air gap.

[0060] There is a magnetic isolation bridge 5 between the main body (i.e., main hole body 41) of the magnetic isolation hole 4 and the outer peripheral surface of the rotor core 1, and a part of the magnetic lines of force are allowed to be transmitted to the air gap at the magnetic isolation bridge 5. The width of the magnetic isolation bridge 5 along the radial direction of the rotor core 1 is uniform at all places. When the value of L / δ is set in the range of 0.5 to 1.5, the magnetic flux transmitted at the magnetic isolation bridge 5 is optimal, the air gap magnetic flux waveform is optimally improved, the peak value of the electromagnetic force density of the motor reaches the lowest, and the vibration noise of the motor also reaches the lowest.

[0061] like Figure 5 and Figure 6 As shown, the magnetic isolation hole 4 has a first end and a second end arranged in a direction close to the axis of the rotor core 1. From the first end to the second end, the magnetic isolation hole 4 gradually moves away from the magnetic pole center line 31 of the corresponding magnetic pole 3; or from the first end to the second end, the magnetic isolation hole 4 gradually approaches the magnetic pole center line 31 of the corresponding magnetic pole 3. In this way, the magnetic permeability distribution in the middle of the magnetic pole 3 of the rotor structure can be changed, the magnetic flux direction can be changed, the air gap magnetic field waveform can be improved, the peak value of the electromagnetic force density of the motor can be reduced, and the vibration noise of the motor can be reduced.

[0062] like Figure 5 As shown, in the embodiment provided by the present invention, the side wall of the magnetic isolation hole 4 close to the magnetic pole center line 31 of the corresponding magnetic pole 3 is inclined relative to the magnetic pole center line 31; each magnetic pole 3 includes a plurality of magnetic isolation holes 4, and the plurality of magnetic isolation holes 4 are arranged in pairs; the minimum distance between two pairs of magnetic isolation holes 4 is O, and the maximum distance between two pairs of magnetic isolation holes 4 is P; 0.9≥O / P≥0.3.

[0063] The main hole body 41 of the magnetic isolation hole 4 at the magnetic pole 3 is tilted relative to the magnetic pole center line 31 of the magnetic pole 3. The side of the magnetic isolation hole 4 close to the outer peripheral surface of the rotor core 1 is closer to the magnetic pole center line 31 than the side of the magnetic isolation hole 4 close to the axis of the rotor core 1. The distance between the two magnetic isolation holes 4 close to the outer peripheral surface of the rotor core 1 is O, and the distance between the two magnetic isolation holes 4 close to the axis of the rotor core 1 is P. The intermediate magnetic bridge between the two magnetic isolation holes 4 affects the magnetic flux density in the middle of the magnetic pole. When the value of O / P is set within the range of 0.3 to 0.9, the magnetic flux distribution in the middle of the magnetic pole 3 can be made more uniform, the waveform sinusoidality is better, and the magnetic permeability of the entire magnetic circuit during the operation of the motor is more uniform, further improving the air gap magnetic flux density at various locations on the outer peripheral surface of the rotor core 1, reducing the peak value of the electromagnetic force density of the motor, and reducing the vibration noise of the motor.

[0064] The present invention provides a motor, comprising a stator structure and a rotor structure, wherein the rotor structure is the above-mentioned rotor structure, so that the vibration noise of the motor can be reduced.

[0065] The present invention provides a compressor comprising a motor, wherein the motor is the motor described above, so that the vibration noise of the compressor can be reduced.

[0066] like Figure 8 As shown in FIG. 1 , it is a comparison diagram of the torque pulsation of the existing motor and the motor of the present application. Figure 8 It can be clearly seen that the torque pulsation of the motor of the present application is much smaller than the torque pulsation of the existing motor.

[0067] like Fig. 9 The figure is a comparison diagram of the measured proportion of back-EMF harmonics of the existing motor and the motor of the present application. Fig. 9 It can be clearly seen that the proportion of back-EMF harmonics in the motor of the present application is much smaller than that in the existing motor.

[0068] like Fig.10 As shown, it is a comparison diagram of the peak values ​​of the electromagnetic force density of the existing motor and the motor of the present application at 6 times the frequency, 12 times the frequency, 18 times the frequency, 24 times the frequency, 30 times the frequency and 36 times the frequency. Fig.10 It can be clearly seen that the peak values ​​of the electromagnetic force density at 6 times, 18 times and 36 times the frequency of the motor of the present application are much smaller than the peak values ​​of the electromagnetic force density at 6 times, 18 times and 36 times the frequency of the existing motor.

[0069] like Fig.11 As shown in FIG. 1 , it is a comparison diagram of the total noise values ​​of the compressor with the existing motor and the compressor with the motor of the present application. Fig.11 It can be clearly seen that the total noise value of the compressor with the motor of the present application is much smaller than the total noise value of the compressor with the existing motor.

[0070] The rotor structure provided by the present invention comprises a rotor core 1 and a permanent magnet 2. The permanent magnet 2 is arranged in a permanent magnet slot on the rotor core 1, and the permanent magnet 2 on the rotor forms an alternately distributed N pole and S pole. A magnetic isolation hole 4 is opened on the magnetic pole 3 of the rotor core 1, and the magnetic isolation hole 4 has both a main hole body 41 extending in the radial direction of the rotor core 1, that is, the middle part of the magnetic isolation hole 4, and a first branch hole 42 and a second branch hole 43 extending in the circumferential direction of the rotor, and the first branch hole 42 and the second branch hole 43 are both arranged on the same side of the extension direction of the main hole body 41, so that the shape of the magnetic isolation hole 4 is an inverted "concave" structure with wide ends and narrow middle in the radial direction of the rotor core 1, and the width of the magnetic isolation hole 4 along the radial direction and circumferential direction of the rotor core 1 has a gradient change.

[0071] The permanent magnet motor generates the main magnetic field by the permanent magnet 2. The permanent magnet motor has high air gap flux density, high working efficiency, small size, high power density, simple structure, high reliability, and is widely used in various industries. However, in the permanent magnet synchronous motor, the permanent magnet 2 made of a fixed grade of material has a constant magnetic energy product, and the air gap magnetic field of the motor is difficult to adjust. At the same time, the tooth structure of the motor makes the air gap flux density and back electromotive force have a large harmonic content, and the electromagnetic force density peak of the motor is large, which leads to large torque pulsation and vibration noise of the motor.

[0072] The present invention changes the magnetic resistance distribution of magnetic circuits at various locations of the motor by opening magnetic isolation holes 4 with an inverted "concave"-shaped structure on the rotor core 1, thereby reducing the cogging effect of the motor, reducing the torque pulsation of the motor, improving the air gap flux density waveform, and reducing the proportion of back-electromotive force harmonics of the motor, reducing the peak value of the electromagnetic force density of the motor, and reducing the electromagnetic vibration noise of the motor. The present invention solves the problems of high air gap flux density and back-electromotive force waveform distortion rate, large proportion of back-electromotive force harmonics, large motor torque pulsation, large motor electromagnetic force, large motor vibration and large noise of the permanent magnet synchronous motor.

[0073] By applying the technical solution of the present invention, a rotor structure is provided, which includes a rotor core 1, a plurality of permanent magnets 2 and a magnetic isolation hole 4, wherein the plurality of permanent magnets 2 are evenly distributed on the rotor core 1 around the axis of the rotor core 1 to form a plurality of magnetic poles 3, including an N pole and an S pole; a magnetic isolation hole 4 is opened on at least one magnetic pole 3, and the magnetic isolation hole 4 includes a main hole body 41 (i.e., the main stem of the magnetic isolation hole 4), a first branch hole 42 and a second branch hole 43 (i.e., the branch portion of the magnetic isolation hole 4) that are interconnected; a plane perpendicular to the axis of the rotor core 1 is taken as a predetermined plane, and the projection of the main hole body 41 on the predetermined plane is in the shape of a strip (i.e., the cross-sectional shape of the main hole body 41 in the direction perpendicular to the axis of the rotor core 1). The surface is strip-shaped) and its extension direction is cross-arranged with the circumferential direction of the rotor core 1. The projections of the first branch hole 42 and the second branch hole 43 on the predetermined plane are strip-shaped. The first branch hole 42 and the second branch hole 43 are cross-arranged with the projection of the main hole body 41 on the predetermined plane and are located on the same side of the main hole body 41, which makes the width of the magnetic isolation hole 4 have a gradient change, that is, on the cross section of the magnetic isolation hole 4 perpendicular to the axial direction of the rotor core 1, the dimensions of the cross section along the radial and circumferential directions of the rotor core 1 are gradient-changed, and along the axial direction of the rotor core 1, the size and shape of the cross section of the magnetic isolation hole 4 perpendicular to the axial direction of the rotor core 1 are unchanged. Through the technical solution provided by the present invention, the magnetic resistance distribution at various parts of the motor magnetic circuit is effectively improved, the direction of the magnetic flux is improved, the air gap magnetic field distribution is adjusted, the air gap magnetic density waveform is improved, the cogging effect of the motor is reduced, the proportion of back-electromotive force harmonics of the motor is reduced, the torque pulsation of the motor is reduced, the peak value of the electromagnetic force density of the motor is reduced, and the electromagnetic vibration noise of the motor is reduced, thereby solving the problem of large vibration noise of the motor in the prior art.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A rotor structure, comprising a rotor core (1) and a plurality of permanent magnets (2) arranged on the rotor core (1) to form a plurality of magnetic poles (3) on the rotor core (1), wherein the plurality of magnetic poles (3) comprise a plurality of N poles and a plurality of S poles alternately arranged along the circumferential direction of the rotor core (1); characterized in that: At least one of the magnetic poles (3) of the rotor core (1) is provided with a magnetic isolation hole (4), the magnetic isolation hole (4) comprising a main hole body (41), a first branch hole (42) and a second branch hole (43) which are interconnected; The plane perpendicular to the axis of the rotor core (1) is taken as the predetermined plane, the projection of the main hole body (41) on the predetermined plane is in the shape of a strip and its extension direction is arranged to intersect the circumferential direction of the rotor core (1), and the projections of the first branch hole (42) and the second branch hole (43) on the predetermined plane are located on the same side of the main hole body (41); Each of the magnetic poles (3) comprises a plurality of magnetic isolation holes (4), and the plurality of magnetic isolation holes (4) are arranged in pairs; The two magnetic isolation holes (4) in a pair are symmetrically arranged relative to the magnetic pole center line (31) of the corresponding magnetic pole (3); and / or The free ends of the first branch hole (42) and the second branch hole (43) of each of the magnetic isolation holes (4) extend in a direction away from or close to the magnetic pole center line (31); and / or The first branch hole (42) and the second branch hole (43) are arranged in a direction close to the axis of the rotor core (1); the two paired magnetic isolation holes (4) are arranged in parallel and the distance between them is F; the minimum distance between the second branch hole (43) and the permanent magnet (2) on one side of the corresponding magnetic pole (3) is D; the projection of the second branch hole (43) on the predetermined plane is a strip with a minimum width of C; the thickness of the permanent magnet (2) is E; wherein 2.5≥(C+E) / (D+F)≥0.3; The first branch hole (42) and the second branch hole (43) are arranged in a direction close to the axis of the rotor core (1); the projection of the first branch hole (42) on the predetermined plane is a bar with a width of H, the projection of the second branch hole (43) on the predetermined plane is a bar with a width of G, and the total length of the magnetic isolation hole (4) along the extension direction of the first branch hole (42) is J; wherein 0.8≥(G+H) / J≥0.

3.

2. The rotor structure according to claim 1, characterized in that: The projection of the main hole body (41) on the predetermined plane extends along the radial direction of the rotor core (1); or The extension direction of the projection of the main hole body (41) on the predetermined plane is parallel to the magnetic pole center line (31) of the corresponding magnetic pole (3).

3. The rotor structure according to claim 1, characterized in that: The extension direction of the projections of the first branch hole (42) and the second branch hole (43) on the predetermined plane is perpendicular to the extension direction of the main hole body (41) on the predetermined plane; or, The extension direction of the projections of the first branch hole (42) and the second branch hole (43) on the predetermined plane extends along the circumferential direction of the rotor core (1).

4. The rotor structure according to claim 1, characterized in that: The projection of the first branch hole (42) on the predetermined plane is in the shape of a strip and has a length of A, and the maximum width of the projection of the main hole body (41) on the predetermined plane is B; wherein 4≥A / B≥1.

3.

5. The rotor structure according to claim 1, characterized in that: The first branch hole (42) and the second branch hole (43) are arranged in a direction close to the axis of the rotor core (1); the minimum distance between the second branch hole (43) and the permanent magnet (2) on one side of the corresponding magnetic pole (3) is D, and the projection of the second branch hole (43) on the predetermined plane is a strip shape with a minimum width of C; wherein 3≥C / D≥0.

8.

6. The rotor structure according to claim 1, characterized in that: The first branch hole (42) and the second branch hole (43) are arranged in a direction close to the axis of the rotor core (1); the length of the projection of the first branch hole (42) on the predetermined plane is A, and the length of the projection of the second branch hole (43) on the predetermined plane is C; wherein 3.1≥C / A≥1.

2.

7. The rotor structure according to claim 1, characterized in that: The first branch hole (42) and the second branch hole (43) are arranged in a direction close to the axis of the rotor core (1); a magnetic isolation bridge (5) is formed between the first branch hole (42) and the outer peripheral surface of the rotor core (1); Along the circumferential direction of the rotor core (1), the width of the magnetic isolation bridge (5) along the radial direction of the rotor core (1) is consistent; and / or The width of the magnetic isolation bridge (5) along the radial direction of the rotor core (1) is L, and the width of the motor air gap of the motor formed by the rotor structure is δ; wherein 1.5≥L / δ≥0.

5.

8. The rotor structure according to claim 1, characterized in that: The magnetic isolation hole (4) has a first end and a second end which are arranged in a direction close to the axis of the rotor core (1). In a direction from the first end to the second end, the magnetic isolation hole (4) gradually moves away from the magnetic pole center line (31) of the corresponding magnetic pole (3); or In a direction from the first end to the second end, the magnetic isolation hole (4) gradually approaches the magnetic pole center line (31) of the corresponding magnetic pole (3).

9. The rotor structure according to claim 1, characterized in that: The side wall of the magnetic isolation hole (4) close to the magnetic pole center line (31) of the corresponding magnetic pole (3) is arranged obliquely relative to the magnetic pole center line (31); each magnetic pole (3) comprises a plurality of magnetic isolation holes (4), and the plurality of magnetic isolation holes (4) are arranged in pairs; the minimum distance between the two magnetic isolation holes (4) in a pair is O, and the maximum distance between the two magnetic isolation holes (4) in a pair is P; 0.9≥O / P≥0.

3.

10. A motor, comprising a stator structure and a rotor structure, characterized in that: The rotor structure is the rotor structure according to any one of claims 1 to 9.

11. A compressor, comprising a motor, characterized in that: The motor is the motor according to claim 10.

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