Rotor Structure, Motor and Compressor

Abstract

The main object of the present invention is to provide a rotor structure, a motor and a compressor. 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. The plurality of magnetic poles include a plurality of N poles and a plurality of S poles alternately arranged along the circumferential direction of the rotor core. At least one magnetic pole of the rotor core is provided with a magnetic isolation hole. The magnetic isolation hole includes a main hole body, a first branch hole and a second branch hole. The first branch hole and the second branch hole are arranged on opposite sides of the main hole body. Wherein, taking the plane perpendicular to the axis of the rotor core as a predetermined plane, the projection of the main hole body on the predetermined plane is strip-shaped and its extending direction intersects with the circumferential direction of the rotor core. The projections of the first branch hole and the second branch hole on the predetermined plane are both strip-shaped and the center lines along their extending directions are both connected to the middle part of the main hole body. Through the above arrangement of the present invention, the problem of relatively large vibration and noise of the motor in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of motors, and more particularly, 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 cost, due to its excellent performance and low price, the development of permanent magnet motor technology has been greatly promoted. The rich resources of permanent magnet materials have promoted the research and development of permanent magnet motor technology.

[0003] Permanent magnet motors rely on permanent magnets to generate the main magnetic field. Compared with ordinary induction motors, permanent magnet synchronous motors do not require reactive excitation current, and the rotor resistance loss is zero under 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 energy indexes, and its economic and social benefits are very significant, and it is widely used in all walks of life.

[0004] However, for the permanent magnet materials of permanent magnet synchronous motors, the magnetic energy product of permanent magnets with fixed grades and materials remains unchanged, and it is difficult to adjust the air-gap magnetic field of the motor. At the same time, the tooth-slot structure of the motor makes the harmonic content of the air-gap magnetic density and back electromotive force relatively large, and the peak value of the electromagnetic force density of the motor is large, resulting in relatively large torque ripple and vibration noise of the motor. Summary of the Invention

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

[0006] To achieve the above object, according to the first aspect of the present invention, a rotor structure is provided, including a rotor core and a plurality of permanent magnets disposed on the rotor core to form a plurality of magnetic poles on the rotor core. The plurality of magnetic poles include a plurality of N poles and a plurality of S poles alternately arranged along the circumferential direction of the rotor core; at least one magnetic pole of the rotor core is provided with a magnetic isolation hole, and the magnetic isolation hole includes a main hole body, a first branch hole, and a second branch hole. The first branch hole and the second branch hole are disposed on opposite sides of the main hole body; wherein, with a plane perpendicular to the axis of the rotor core as a predetermined plane, the projection of the main hole body on the predetermined plane is strip-shaped and its extending direction intersects with the circumferential direction of the rotor core, and the projections of the first branch hole and the second branch hole on the predetermined plane are both strip-shaped and the center lines along their extending directions are both connected to the middle part of the main hole body.

[0007] Furthermore, the projections of the first branch hole and the second branch hole on the predetermined plane are perpendicular to the projection of the main hole body on the predetermined plane; and / or the projection of the main hole body on the predetermined plane extends along the radial direction of the rotor core or is parallel to the magnetic pole center line of the magnetic pole; and / or the center lines of the projections of the first branch hole and the second branch hole on the predetermined plane are located on the same straight line.

[0008] Further, on a predetermined plane, one end of the first branch hole is connected to the middle part of the main hole body, and the other end of the first branch hole extends towards the permanent magnet close to the first branch hole; and / or on the predetermined plane, one end of the second branch hole is connected to the middle part of the main hole body, and the other end of the second branch hole extends towards the direction of the magnetic pole center line of the corresponding magnetic pole.

[0009] Further, 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 B; wherein, A≥B.

[0010] Further, 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 B; wherein, 4.6≥A / B≥1.5.

[0011] Further, 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 B; the width of the projection of the main hole body on the predetermined plane is C; wherein, 0.5≥C / (A+B+C)≥0.1.

[0012] Further, each magnetic pole has 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 with respect to the magnetic pole center line of the corresponding magnetic pole.

[0013] Further, the minimum distance between the two magnetic isolation holes in a pair is E, the minimum distance between each magnetic isolation hole and the permanent magnet located on one side of the corresponding magnetic pole and close to the magnetic isolation hole is D, and the thickness of the permanent magnet is F; wherein, 5.8≥(D+E) / F≥1.5.

[0014] Further, the two magnetic isolation holes in a pair are arranged at intervals so as to form an intermediate magnetic bridge between the two magnetic isolation holes in a pair.

[0015] Further, the main hole bodies of the two magnetic isolation holes in a pair are arranged in parallel and the distance therebetween is G, and the minimum distance between the two magnetic isolation holes in a pair is E; wherein, 0.6≥E / G≥0.2.

[0016] Further, the projection of each main hole body on the predetermined plane tends to the magnetic pole center line of the corresponding magnetic pole; the included angle between the main hole bodies of the two magnetic isolation holes in a pair is N, and the included angle between the permanent magnets on both sides of the magnetic pole is O; wherein, 0.5≥N / O≥0.03.

[0017] Further, the width of the projection of the first branch hole on the predetermined plane is H, and the length of the projection of the main hole body on the predetermined plane is J; wherein, 0.4≥J / H≥0.05.

[0018] Further, the minimum distance between the magnetic isolation hole and the permanent magnet located on one side of the corresponding magnetic pole and close to the magnetic isolation hole is K, the thickness of the permanent magnet is F, and the length of the projection of the main hole body on a predetermined plane is J, where 0.35 ≥ K / (F + J) ≥ 0.08.

[0019] Further, the end surface of the main hole body on the side close to the outer peripheral surface of the rotor core is arranged parallel to the outer peripheral surface of the rotor core and the distance therebetween is P, and the width of the motor air gap of the motor formed by the rotor structure is δ; where 1.7 ≥ P / δ ≥ 0.4.

[0020] Further, along the direction away from the axis of the rotor core, the main hole body includes a first hole section and a second hole section, and the first hole section and the second hole section are respectively located on both sides of the first branch hole; where the included angle between the projection of the first branch hole on a predetermined plane and the projection of the second hole section on the predetermined plane is L, where 140° ≥ L ≥ 45°.

[0021] Further, the included angle between the projection of the second branch hole on a predetermined plane and the projection of the first hole section on the predetermined plane is M; where L = M.

[0022] According to the second aspect of the present invention, an electrode is provided, which includes a stator structure and a rotor structure, and the rotor structure is the above-mentioned rotor structure.

[0023] According to the third aspect of the present invention, a compressor is provided, which includes a motor, and the motor is the above-mentioned motor.

[0024] The present invention provides a rotor structure having a rotor core, a plurality of permanent magnets, and magnetic isolation holes. Among them, the plurality of permanent magnets are evenly distributed around the axis of the rotor core on the rotor core to form a plurality of magnetic poles, including N poles and S poles, and at least one magnetic pole is provided with a magnetic isolation hole. Among them, the magnetic isolation hole includes a main hole body, a first branch hole, and a second branch hole, and the first branch hole and the second branch hole are arranged on opposite sides of the main hole body. Taking the plane perpendicular to the axis of the rotor core as a predetermined plane, the projections of the main hole body, the first branch hole, and the second branch hole on the predetermined plane are all strip-shaped, the extending direction of the main hole body intersects with the circumferential direction of the rotor core, the center lines of the extending directions of the first branch hole and the second branch hole are both connected to the main hole body and are located at positions close to the middle section of the main hole body. This makes the width of the magnetic isolation hole have a gradient change in the circumferential direction and the radial direction of the rotor core 1, that is, the dimensions of the magnetic isolation hole in the radial and circumferential directions of the rotor core are both gradient-changing. At the same time, the size and shape of the magnetic isolation hole in the axial direction of the rotor core are unchanged. Through the technical solution provided by the present invention, the technical effects of effectively improving the magnetic resistance distribution at various parts of the motor magnetic circuit, improving the magnetic flux direction, adjusting the air gap magnetic field distribution, improving the air gap magnetic density waveform, reducing the cogging effect of the motor, reducing the proportion of back electromotive force harmonics of the motor, reducing the torque ripple of the motor, reducing the peak value of the electromagnetic force density of the motor, and reducing the electromagnetic vibration noise of the motor are achieved, and the problem of large vibration noise of the motor in the prior art is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0026] Figure 1 shows a schematic structural diagram of a rotor structure according to a first embodiment of the present invention;

[0027] Figure 2 shows Figure 1 a schematic diagram of the magnetic flux direction of the shown rotor structure;

[0028] Figure 3 shows a schematic structural diagram of a rotor structure according to a second embodiment of the present invention;

[0029] Figure 4 shows a schematic structural diagram of a rotor structure according to a third embodiment of the present invention;

[0030] Figure 5 shows a schematic structural diagram of a rotor structure according to a fourth embodiment of the present invention;

[0031] Figure 6 shows a schematic structural diagram of a rotor structure according to a fifth embodiment of the present invention;

[0032] Figure 7 Shows a comparison chart of the measured torque ripple of the existing motor and the motor of the present application;

[0033] Figure 8 Shows a comparison chart of the proportion of back electromotive force harmonics of the measured existing motor and the motor of the present application;

[0034] Figure 9 Shows a comparison chart of the peak value of electromagnetic force density of the measured existing motor and the motor of the present application; and

[0035] Figure 10 Shows a comparison chart of the total noise of the compressor with the existing motor and the compressor with the motor of the present application measured.

[0036] Among them, the above-mentioned drawings include the following reference numerals:

[0037] 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. Intermediate magnetic bridge; 6. Magnetic isolation bridge; 7. Magnetic conduction path; 71. First path area; 72. Second path area; 73. Third path area. Detailed implementation manners

[0038] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0039] As Figures 1 to 6 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 to form a plurality of magnetic poles 3 on the rotor core 1. The plurality of magnetic poles 3 include a plurality of N poles and a plurality of S poles alternately arranged along the circumferential direction of the rotor core 1; at least one magnetic pole 3 of the rotor core 1 is provided with a magnetic isolation hole 4. The magnetic isolation hole 4 includes a main hole body 41, a first branch hole 42 and a second branch hole 43. The first branch hole 42 and the second branch hole 43 are arranged on opposite sides of the main hole body 41; wherein, taking the plane perpendicular to the axis of the rotor core 1 as the predetermined plane, the projection of the main hole body 41 on the predetermined plane is strip-shaped and its extending direction intersects 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 both strip-shaped and the center lines along their extending directions are both connected to the middle part of the main hole body 41.

[0040] The present invention provides a rotor structure having a rotor core 1, a plurality of permanent magnets 2, and magnetic isolation holes 4. Among them, the plurality of permanent magnets 2 are evenly distributed around the axis of the rotor core 1 on the rotor core 1 to form a plurality of magnetic poles 3, including N poles and S poles, and at least one magnetic pole 3 is provided with a magnetic isolation hole 4. Among them, the magnetic isolation hole 4 includes a main hole body 41, a first branch hole 42, and a second branch hole 43, and the first branch hole 42 and the second branch hole 43 are arranged on opposite sides of the main hole body 41. Taking the plane perpendicular to the axis of the rotor core 1 as a predetermined plane, the projections of the main hole body 41, the first branch hole 42, and the second branch hole 43 on the predetermined plane are all strip-shaped. The extending direction of the main hole body 41 intersects with the circumferential direction of the rotor core 1. The center lines of the extending directions of the first branch hole 42 and the second branch hole 43 are both connected to the main hole body 41 and are located at positions close to the middle section of the main hole body 41. This enables the magnetic isolation hole 4 to have a gradient change in width along the circumferential direction and the radial direction of the rotor core 1, that is, the dimensions of the magnetic isolation hole 4 along the radial and circumferential directions of the rotor core 1 both have gradient changes. At the same time, the size and shape of the magnetic isolation hole 4 along the axis direction of the rotor core 1 are unchanged. Through the technical solution provided by the present invention, the technical effects of effectively improving the magnetic resistance distribution at various parts of the motor magnetic circuit, improving the magnetic flux direction, adjusting the air-gap magnetic field distribution, improving the air-gap magnetic density waveform, reducing the cogging effect of the motor, reducing the proportion of back-EMF harmonics in the motor, reducing the torque ripple of the motor, reducing the peak value of the electromagnetic force density of the motor, and reducing the electromagnetic vibration noise of the motor are achieved, and the problem of large vibration noise of the motor in the prior art is solved.

[0041] Specifically, the rotor core 1 is made of a material with strong magnetic conductivity, which makes the magnetic resistance of the rotor core 1 smaller. Optionally, the rotor core 1 is formed by stacking a plurality of silicon steel sheets, which makes the magnetic force lines easy to pass through. Since the inside of the magnetic isolation hole 4 is made of non-magnetic materials such as air, the magnetic conductivity is poor and the magnetic resistance is large, and the magnetic force lines are not easy to pass through. Therefore, by providing such a magnetic isolation hole 4, the magnetic resistance distribution at various parts of the magnetic circuit of the motor rotor structure can be changed, the magnetic force line direction inside the rotor structure can be changed, and the air-gap magnetic density waveform can be improved, thereby reducing the proportion of back-EMF harmonics, reducing the torque ripple of the motor, reducing the electromagnetic force amplitude, and reducing the electromagnetic vibration noise of the motor.

[0042] As Figure 2 shown, it 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 identifications of the magnetic force lines. The solid lines with arrows indicate that there are more magnetic force lines passing through at that position, and the dotted lines with arrows indicate that there are fewer magnetic force lines passing through at that position. It can be clearly seen from Figure 2 that at the position where the magnetic isolation hole 4 is located, fewer magnetic force lines pass through. The magnetic isolation hole 4 provided by the present invention effectively improves the magnetic force line distribution of the rotor structure.

[0043] As Figure 1As shown, the projections of the first branch hole 42 and the second branch hole 43 on a predetermined plane are perpendicular to the projection of the main hole body 41 on the predetermined plane; and / or the projection of the main hole body 41 on the predetermined plane extends along the radial direction of the rotor core 1 or is parallel to the magnetic pole center line 31 of the magnetic pole 3; and / or the center lines of the projections of the first branch hole 42 and the second branch hole 43 on the predetermined plane are located on the same straight line.

[0044] As Figures 1 to 6 shown, on the predetermined plane, one end of the first branch hole 42 is connected to the middle part of the main hole body 41, and the other end of the first branch hole 42 extends towards the permanent magnet 2 close to the first branch hole 42; and / or on the predetermined plane, one end of the second branch hole 43 is connected to the middle part of the main hole body 41, and the other end of the second branch hole 43 extends towards the direction of the magnetic pole center line 31 of the corresponding magnetic pole 3.

[0045] In the rotor structure provided by the present invention, due to the adoption of the magnetic isolation hole 4 with a "cross" structure, the magnetic isolation hole 4 has a main hole body 41 extending along the radial direction of the rotor core 1, that is, the main part of the magnetic isolation hole 4, and also has a first branch hole 42 and a second branch hole 43 extending along the circumferential direction of the rotor.

[0046] The heads of the first branch hole 42 and the second branch hole 43 both extend from the same position near the middle of the main part of the magnetic isolation hole 4. Since the heads of the first branch hole 42 and the second branch hole 43 are connected to the main part of the magnetic isolation hole 4, the magnetic resistance at the heads of the first branch hole 42 and the second branch hole 43 is large; and the tail of the first branch hole 42 is close to the permanent magnet 2, and the tail of the second branch hole 43 is close to the magnetic pole center line 31. This makes the shape of the magnetic isolation hole 4 a "cross" structure that is narrow at both ends and wide in the middle along the direction away from the axis of the rotor core 1, and the widths of the magnetic isolation hole 4 along the circumferential direction and the radial direction of the rotor core 1 both have gradient changes. This makes the magnetic resistance at each part of the circumferential direction of the rotor core not equal, which, in cooperation with the stator teeth and slots, makes the magnetic conductance at each part of the magnetic circuit more uniform when the motor operates, thereby improving the air-gap magnetic field distribution of the motor, reducing the air-gap magnetic density waveform of the motor, reducing the torque ripple of the motor, reducing the proportion of the back electromotive force harmonics of the motor, and reducing the peak value of the electromagnetic force density of the motor and the vibration noise of the motor.

[0047] As Figure 1 shown, 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 B; wherein, A≥B.

[0048] Preferably, 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 B; wherein, 4.6≥A / B≥1.5.

[0049] The projections of the first branch hole 42 and the second branch hole 43 on a predetermined plane are strip-shaped. The length A of the projection of the first branch hole 42 on the predetermined plane is the width of the first branch hole 42 in the circumferential direction of the rotor core 1; the length B of the projection of the second branch hole 43 on the predetermined plane is the width of the second branch hole 43 in the circumferential direction of the rotor core 1.

[0050] The width of the first branch hole 42 in the circumferential direction of the rotor core 1 is greater than the width of the second branch hole 43 in the circumferential direction of the rotor core 1. When the value of A / B is set within the range of 1.5 to 4.6, it can ensure that the intermediate magnetic bridge 5 between the two second branch holes 43 of the same magnetic pole 3 is not too short, and at the same time, make the first branch hole 42 closer to the permanent magnet 2 to change the magnetic flux direction emitted by the permanent magnet 2, improve the air-gap magnetic density waveform, thereby reducing the vibration and noise of the motor, and ensuring the output torque of the motor.

[0051] As Figure 1 shown, 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 B; the width of the projection of the main hole body 41 on the predetermined plane is C; wherein, 0.5≥C / (A + B + C)≥0.1.

[0052] The width C of the projection of the main part (i.e., the main hole body 41) of the magnetic isolation hole 4 on the predetermined plane is the width of the magnetic isolation hole 4 in the circumferential direction of the rotor core 1. Along the radial direction of the rotor core 1, the width of the magnetic isolation hole 4 in the circumferential direction of the rotor core 1 is narrow at both ends, which can ensure that the rotor core provides sufficient core magnetic conduction paths, and wide in the middle, which can change the magnetic flux direction.

[0053] When the value of C / (A + B + C) is set within the range of 0.1 to 0.5, it can effectively change the magnetic flux direction, thereby improving the magnetic density distribution at and around the magnetic isolation hole 4 with a "cross" structure, optimizing the air-gap magnetic density waveform, and reducing the peak value of the electromagnetic force density and the vibration and noise of the motor.

[0054] As Figures 1 to 6 shown, each magnetic pole 3 has 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 with respect to the magnetic pole center line 31 of the corresponding magnetic pole 3.

[0055] As Figure 1 shown, the minimum distance between the two magnetic isolation holes 4 in a pair is E, the minimum distance between each magnetic isolation hole 4 and the permanent magnet 2 located on one side of the corresponding magnetic pole 3 and close to the magnetic isolation hole 4 is D, and the thickness of the permanent magnet 2 is F; wherein, 5.8≥(D + E) / F≥1.5.

[0056] There are at least two "cross-shaped" magnetic isolation holes 4 on each magnetic pole 3. The two magnetic isolation holes 4 are symmetrically arranged with respect to the magnetic pole center line 31. There is a distance between the two magnetic isolation holes 4. The distance between the second branch holes 43 of the two magnetic isolation holes 4 is E. There is a distance between the first branch holes 42 of the two magnetic isolation holes 4 and the two permanent magnets 2 respectively, and this distance is D. The thickness of the permanent magnet is F.

[0057] There are three magnetic conduction paths 7 on each magnetic pole 3 of the rotor structure. There is a distance between the two second branch holes 43 to allow magnetic flux to pass through, which is the third path region 73. There is a distance between each of the two first branch holes 42 and the permanent magnet 2 it is close to, which are the first path region 71 and the second path region 72 respectively. The magnetic resistance at the three magnetic conduction paths 7 is small and allows magnetic flux to pass through, while the inside of the magnetic isolation hole 4 is made of non-magnetic substances such as air, and the magnetic resistance is large, and only a small part of the magnetic flux can pass through.

[0058] When the value of (D + E) / F is set within the range of 1.5 to 5.8, it can effectively improve the magnetic flux at each magnetic conduction path 7, thereby improving the air-gap magnetic density waveform of the motor, reducing the torque ripple of the motor, and reducing the peak value of the electromagnetic force density of the motor and the electromagnetic vibration noise of the motor.

[0059] As Figure 1 shown, the two magnetic isolation holes 4 in a pair are arranged at intervals so that an intermediate magnetic bridge is formed between the two magnetic isolation holes 4 in a pair.

[0060] There is a distance between the two magnetic isolation holes 4 arranged in pairs on each magnetic pole 3, so that the width of the intermediate magnetic bridge 5 between the two magnetic isolation holes 4 has a gradient change along the circumferential direction of the rotor core 1. Along the direction away from the axis of the rotor core 1, the change in the width of the magnetic isolation hole 4 is "wide - narrow - wide". The width of the middle part of the intermediate magnetic bridge 5 along the circumferential direction of the rotor core 1 is small to reduce the magnetic flux conducted at the intermediate magnetic bridge 5; while the width of both ends of the intermediate magnetic bridge 5 along the circumferential direction of the rotor core 1 is large, which also makes the magnetic flux conducted at the intermediate magnetic bridge 5 not too small. At the same time, the width of the intermediate magnetic bridge 5 near the outer peripheral surface of the rotor core 1 is large, that is, its width near the air-gap side is large, which further improves the air-gap magnetic density distribution corresponding to the intermediate magnetic bridge 5, improves the air-gap magnetic density waveform, reduces harmonics, and reduces the peak value of the electromagnetic force density of the motor and the electromagnetic vibration noise of the motor.

[0061] As Figure 1 shown, the main hole bodies 41 of the two magnetic isolation holes 4 in a pair are arranged in parallel and the distance is G, and the minimum distance between the two magnetic isolation holes 4 in a pair is E; among them, 0.6 ≥ E / G ≥ 0.2.

[0062] Between the two magnet isolation holes 4 arranged in pairs is the middle magnetic bridge 5. The distance G between the main hole bodies 41 of the two magnet isolation holes 4 is also the width of the middle magnetic bridge 5 along the circumferential direction of the rotor core 1 at both ends. The minimum distance E between the two magnet isolation holes 4 is the distance between the second branch holes 43 of the two magnet isolation holes 4 arranged in pairs, that is, the minimum width of the middle magnetic bridge 5 along the circumferential direction of the rotor core 1. Since the main hole bodies 41 of the two magnet isolation holes 4 are parallel to each other, the width of one end of the middle magnetic bridge 5 close to the axis of the rotor core 1 is equal to the width of the other end close to the outer circumferential surface of the rotor core 1, and this width is G.

[0063] When the value of E / G is set within the range of 0.2 to 0.6, the sinusoidality of the air-gap magnetic density waveform reaches the optimum, 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.

[0064] As Figure 5 and Figure 6 shown, the projections of the respective main hole bodies 41 on a predetermined plane all tend to the magnetic pole center line 31 of the corresponding magnetic pole 3; the included angle between the main hole bodies 41 of the two magnet isolation holes 4 arranged in pairs is N, and the included angle between the two permanent magnets 2 on both sides of the magnetic pole 3 is O; among them, 0.5≥N / O≥0.03.

[0065] The main hole bodies 41 of the two magnet isolation holes 4 symmetrically arranged about the magnetic pole center line 31 of each magnetic pole 3 (i.e., the main part of the magnet isolation hole 4) are all inclined with respect to the magnetic pole center line 31, and there is a certain angle between the main parts of the two magnet isolation holes 4, and this angle is N. The angle between the two permanent magnets 2 of each magnetic pole 3 is O. The angle between the two permanent magnets 2 of a single magnetic pole 3 has a great influence on the magnetic flux generated by the permanent magnet 2 along the direction of the magnetic pole 3, thereby affecting the magnetic flux density in each region of the magnetic pole 3.

[0066] When the value of N / O is set within the range of 0.03 to 0.5, the guidance of the main part of the magnet isolation hole 4 to the magnetic flux direction is the best, which makes the magnetic conductance more uniform everywhere in the magnetic circuit, improves the air-gap magnetic density waveform, reduces the torque ripple of the motor, and reduces the peak value of the electromagnetic force density and the vibration noise of the motor.

[0067] As Figure 1 shown, the width of the projection of the first branch hole 42 on a predetermined plane is H, and the length of the projection of the main hole body 41 on a predetermined plane is J; among them, 0.4≥J / H≥0.05.

[0068] The projections of the first branch hole 42 and the main hole body 41 (i.e., the main part of the magnet isolation hole 4) on a predetermined plane are both strip-shaped. The width H of the projection of the first branch hole 42 on a predetermined plane is the length in the radial direction of the rotor core 1; the length J of the projection of the main hole body 41 on a predetermined plane is the length in the radial direction of the rotor core 1.

[0069] The length of the first branch hole 42 in the radial direction of the rotor core 1 is less than the length of the main part of the magnetic isolation hole 4 in the radial direction of the rotor core 1. Since the first branch hole 42 extends in the circumferential direction of the rotor core 1, this hinders the transmission of the magnetic flux generated by the permanent magnet 2 to the air gap. The longer the length of the first branch hole 42 in the radial direction of the rotor core 1, the greater the magnetic resistance of the first branch hole 42, and the stronger its ability to hinder the conduction of magnetic flux. Therefore, if the first branch hole 42 is too long in the radial direction of the rotor core 1, the output torque of the motor will be reduced.

[0070] When the value of J / H is set within the range of 0.05 to 0.4, while ensuring the output torque of the motor, the peak value of the electromagnetic force density of the motor can be minimized, and the vibration and noise of the motor can also be minimized.

[0071] As Figure 1 shown, the minimum distance between the magnetic isolation hole 4 and the permanent magnet 2 located on one side of the corresponding magnetic pole 3 and close to the magnetic isolation hole 4 is K, the thickness of the permanent magnet 2 is F, and the length of the projection of the main hole body 41 on a predetermined plane is J, where 0.35 ≥ K / (F + J) ≥ 0.08.

[0072] The projection of the main part of the magnetic isolation hole 4 (i.e., the main hole body 41) on a predetermined plane is strip-shaped. There is a distance K between the main part of the magnetic isolation hole 4 and the permanent magnet 2; the thickness of the permanent magnet 2 is F; the length of the main part of the magnetic isolation hole 4 is J.

[0073] The magnetic flux is allowed to pass between the main part of the magnetic isolation hole 4 and the permanent magnet 2, so that a part of the magnetic flux on the side of the permanent magnet 2 close to the axis of the rotor core 1 passes from the third path region 73 of the magnetic conduction path 7 at the middle magnetic bridge 5 to the outer peripheral surface of the rotor core 1, and a part passes from the first path region 71 and the second path region 72 of the magnetic conduction path 7 on both sides of the magnetic pole 3 to the outer peripheral surface of the rotor core 1; while the inside of the main part of the magnetic isolation hole 4 is filled with non-magnetic substances such as air, which hinders the passage of magnetic flux from here.

[0074] When the value of K / (F + J) is set within the range of 0.08 to 0.35, the magnetic flux distribution on the magnetic pole 3 can be effectively improved, and the peak value of the electromagnetic force density of the motor and the vibration and noise of the motor can be further reduced.

[0075] Preferably, the end face of the main hole body 41 on the side close to the outer peripheral surface of the rotor core 1 is parallel to the outer peripheral surface of the rotor core 1 and the distance is P; the width of the motor air gap formed by the rotor structure is δ; where 1.7 ≥ P / δ ≥ 0.4.

[0076] Among them, the width δ of the motor air gap formed by the rotor structure is the gap between the rotor and stator of the motor, and the air-gap magnetic density refers to the magnetic induction intensity of the magnetic field existing in the air gap. The distance P between the side wall of the main hole body 41 close to the outer peripheral surface of the rotor core 1 and the outer peripheral surface of the rotor core 1 is the magnetic isolation bridge 6, and a part of the magnetic flux lines are allowed to be transmitted to the air gap at the magnetic isolation bridge 6. Along the circumferential direction of the rotor core 1, the width of the magnetic isolation bridge 6 in the radial direction of the rotor core 1 is uniform. When the value of P / δ is set within the range of 0.4 to 1.7, the magnetic flux transmitted at the magnetic isolation bridge 6 is optimal, the air-gap magnetic density 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.

[0077] As Figure 3 and Figure 4 shown, along the direction away from the axis of the rotor core 1, the main hole body 41 includes a first hole section and a second hole section, and the first hole section and the second hole section are respectively located on both sides of the first branch hole 42; among them, the included angle between the projection of the first branch hole 42 on a predetermined plane and the projection of the second hole section on the predetermined plane is L, where 140° ≥ L ≥ 45°.

[0078] The projections of the first branch hole 42 and the second hole section of the main hole body 41 on the predetermined plane are both strip-shaped, and there is a certain angle between the first branch hole 42 and the second hole section, and this angle is L. When the value of L is within the range of 45° to 140°, the first branch hole 42 is closer to the permanent magnet 2, which can improve the magnetic flux density in different magnetic conduction path 7 regions, improve the air-gap magnetic density waveform, thereby reducing the torque ripple of the motor, and reducing the peak value of the electromagnetic force density of the motor and the vibration noise of the motor.

[0079] As Figure 3 and Figure 4 shown, the included angle between the projection of the second branch hole 43 on the predetermined plane and the projection of the first hole section on the predetermined plane is M; among them, L = M.

[0080] The projections of the second branch hole 43 and the first hole section of the main hole body 41 on the predetermined plane are both strip-shaped, and there is a certain angle between the second branch hole 43 and the first hole section, and this angle is M. When the angle between the second branch hole 43 and the first hole section is equal to the angle between the first branch hole 42 and the second hole section, that is, L = M, the first branch hole 42 is closer to the side of the permanent magnet 2 close to the rotor core axis, and the second branch hole 43 is farther from the side of the permanent magnet 2 close to the rotor core axis, which makes the magnetic conductance of each part of the magnetic circuit in the circumferential and radial directions of the rotor core 1 more uniform, thereby improving the sinusoidality of the air-gap magnetic density waveform, reducing the motor harmonics, and reducing the electromagnetic noise caused by the harmonics.

[0081] The present invention also provides an electrode, comprising a stator structure and a rotor structure, and the rotor structure is the above-mentioned rotor structure. In this way, the vibration and noise of the motor can be reduced.

[0082] The present invention also provides a compressor, comprising a motor, and the motor is the above-mentioned motor. In this way, the vibration and noise of the compressor can be reduced.

[0083] As Figure 7 shown, it is a comparison chart of the torque ripple of the existing motor and the motor of the present application measured. It can be clearly seen in Figure 7 that the range of the torque ripple of the motor of the present application is much smaller than that of the existing motor.

[0084] As Figure 8 shown, it is a comparison chart of the back electromotive force harmonic ratio of the existing motor and the motor of the present application measured. It can be clearly seen in Figure 8 that the back electromotive force harmonic ratio of the motor of the present application is much smaller than that of the existing motor.

[0085] As Figure 9 shown, it is a comparison chart of the peak value of the electromagnetic force density of the existing motor and the motor of the present application measured. It can be clearly seen in Figure 9 that the peak value of the electromagnetic force density of the motor of the present application is much smaller than that of the existing motor.

[0086] As Figure 10 shown, it is a comparison chart of the total noise value of the compressor with the existing motor and the compressor with the motor of the present application measured. It can be clearly seen in Figure 10 that the total noise value of the compressor with the motor of the present application is much smaller than that of the compressor with the existing motor.

[0087] The rotor structure in 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. The permanent magnets 2 on the rotor form alternately distributed N poles and S poles. A magnetic isolation hole 4 is formed on a magnetic pole 3 of the rotor core 1. The magnetic isolation hole 4 has a main hole body 41 extending in the radial direction of the rotor core 1, that is, the main 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 core 1. Among them, both the first branch hole 42 and the second branch hole 43 are connected to the main hole body 41, and are located at a position close to the middle section of the main hole body 41. The extending directions of the first branch hole 42 and the second branch hole 43 are on a straight line. The first branch hole 42 is located on the side close to the permanent magnet 2, and the second branch hole 43 is located on the side close to the magnetic pole center line 31. This makes the magnetic isolation hole 4 have a gradient change in width in both the circumferential and radial directions of the rotor core 1. Along the radial and circumferential directions of the rotor core 1, the magnetic isolation hole 4 is narrow at both ends and wide in the middle, resembling a "cross" structure.

[0088] Permanent magnet motors rely on permanent magnets 2 to generate the main magnetic field. Permanent magnet motors have a high air-gap magnetic flux density, high operating efficiency, small size, high power density, simple structure, and high reliability, and are widely used in various industries. However, in permanent magnet synchronous motors, for the permanent magnets 2 made of materials with a fixed grade, the magnetic energy product remains unchanged, making it difficult to adjust the air-gap magnetic field of the motor. At the same time, the tooth-slot structure of the motor results in a relatively large harmonic content in the air-gap magnetic flux density and back electromotive force, and a large peak value of the electromagnetic force density of the motor, which leads to relatively large torque ripple and vibration noise of the motor.

[0089] In the present invention, by opening magnetic isolation holes 4 with a "cross" structure on the rotor core 1, the magnetic resistance distribution of the magnetic circuits at various parts of the motor is changed, achieving the technical effects of reducing the tooth-slot effect of the motor, reducing the torque ripple of the motor, improving the air-gap magnetic flux density waveform, simultaneously 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, and solving the problems of high distortion rate of the air-gap magnetic flux density and back electromotive force waveform, large proportion of back electromotive force harmonics, large motor torque ripple, large motor electromagnetic force, and large motor vibration and noise in the prior art.

[0090] The present invention provides a rotor structure having a rotor core 1, a plurality of permanent magnets 2, and magnetic isolation holes 4. Among them, the plurality of permanent magnets 2 are evenly distributed around the axis of the rotor core 1 on the rotor core 1 to form a plurality of magnetic poles 3, including N poles and S poles, and at least one magnetic pole 3 is provided with a magnetic isolation hole 4. Among them, the magnetic isolation hole 4 includes a main hole body 41, a first branch hole 42, and a second branch hole 43, and the first branch hole 42 and the second branch hole 43 are arranged on opposite sides of the main hole body 41. Taking the plane perpendicular to the axis of the rotor core 1 as the predetermined plane, the projections of the main hole body 41, the first branch hole 42, and the second branch hole 43 on the predetermined plane are all strip-shaped, the extending direction of the main hole body 41 intersects with the circumferential direction of the rotor core 1, and the center lines of the extending directions of the first branch hole 42 and the second branch hole 43 are both connected to the main hole body 41 and are located at positions close to the middle section of the main hole body 41, which makes the width of the magnetic isolation hole 4 have a gradient change in the circumferential direction and the radial direction of the rotor core 1, that is, the dimensions of the magnetic isolation hole 4 in the radial and circumferential directions of the rotor core 1 both have a gradient change. At the same time, the size and shape of the magnetic isolation hole 4 in the axial direction of the rotor core 1 are unchanged. Through the technical solution provided by the present invention, the technical effects of effectively improving the magnetic resistance distribution at various parts of the motor magnetic circuit, improving the magnetic flux direction, adjusting the air-gap magnetic field distribution, improving the air-gap magnetic flux density waveform, reducing the tooth-slot effect of the motor, reducing the proportion of back electromotive force harmonics of the motor, reducing the torque ripple of the motor, reducing the peak value of the electromagnetic force density of the motor, and reducing the electromagnetic vibration noise of the motor are achieved, and the problem of relatively large vibration and noise of the motor in the prior art is solved.

[0091] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A rotor structure, comprising a rotor core (1) and a plurality of permanent magnets (2) disposed on the rotor core (1) to form a plurality of magnetic poles (3) on the rotor core (1), the plurality of magnetic poles (3) including 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) includes a main hole body (41), a first branch hole (42) and a second branch hole (43), the first branch hole (42) and the second branch hole (43) are disposed on opposite sides of the main hole body (41); wherein, taking a plane perpendicular to the axis of the rotor core (1) as a predetermined plane, the projection of the main hole body (41) on the predetermined plane is strip-shaped and its extending direction intersects 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 both strip-shaped and the center lines along their extending directions are both connected to the middle of the main hole body (41); on the predetermined plane, one end of the first branch hole (42) is connected to the middle of the main hole body (41), and the other end of the first branch hole (42) extends towards the permanent magnet (2) close to the first branch hole (42); and / or, on the predetermined plane, one end of the second branch hole (43) is connected to the middle of the main hole body (41), and the other end of the second branch hole (43) extends towards the direction of the magnetic pole center line (31) of the corresponding magnetic pole (3); each of the magnetic poles (3) has a plurality of the 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 with respect to the magnetic pole center line (31) of the corresponding magnetic pole (3); the two magnetic isolation holes (4) in a pair are spaced apart from each other so that an intermediate magnetic bridge is formed between the two magnetic isolation holes (4) in a pair; along the direction away from the axis of the rotor core (1), the main hole body (41) includes a first hole section and a second hole section, and the first hole section and the second hole section are respectively located on both sides of the first branch hole (42).

2. The rotor structure according to claim 1, characterized in that, the projections of the first branch hole (42) and the second branch hole (43) on the predetermined plane are perpendicular to the projection of the main hole body (41) on the predetermined plane; and / or the projection of the main hole body (41) on the predetermined plane extends along the radial direction of the rotor core (1) or is parallel to the magnetic pole center line (31) of the magnetic pole (3); and / or the center lines of the projections of the first branch hole (42) and the second branch hole (43) on the predetermined plane are located on the same straight line.

3. The rotor structure according to claim 1, wherein, 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 B; wherein, A≥B.

4. The rotor structure according to claim 1, characterized in that, 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 B; wherein, 4.6 ≥ A / B ≥ 1.

5.

5. The rotor structure according to claim 1, characterized in that 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 B; the width of the projection of the main hole body (41) on the predetermined plane is C; wherein, 0.5 ≥ C / (A + B + C) ≥ 0.

1.

6. The rotor structure according to claim 1, wherein, The minimum distance between two paired magnetic isolation holes (4) is E, the minimum distance between each magnetic isolation hole (4) and the permanent magnet (2) located on one side of the corresponding magnetic pole (3) and close to the magnetic isolation hole (4) is D, and the thickness of the permanent magnet (2) is F; wherein, 5.8 ≥ (D + E) / F ≥ 1.

5.

7. The rotor structure according to claim 1, characterized in that, The main hole bodies (41) of two paired magnetic isolation holes (4) are arranged in parallel and the distance therebetween is G, and the minimum distance between two paired magnetic isolation holes (4) is E; wherein, 0.6 ≥ E / G ≥ 0.

2.

8. The rotor structure according to claim 1, wherein, The projection of each main hole body (41) on the predetermined plane tends to the magnetic pole center line (31) of the corresponding magnetic pole (3); the included angle between the main hole bodies (41) of two paired magnetic isolation holes (4) is N, and the included angle between the permanent magnets (2) located on both sides of the magnetic pole (3) is O; wherein, 0.5 ≥ N / O ≥ 0.

03.

9. The rotor structure according to claim 1, wherein, The width of the projection of the first branch hole (42) on the predetermined plane is H, and the length of the projection of the main hole body (41) on the predetermined plane is J; wherein, 0.4 ≥ J / H ≥ 0.

05.

10. The rotor structure according to claim 1, characterized in that, The minimum distance between the magnetic isolation hole (4) and the permanent magnet (2) located on one side of the corresponding magnetic pole (3) and close to the magnetic isolation hole (4) is K, the thickness of the permanent magnet (2) is F, and the length of the projection of the main hole body (41) on the predetermined plane is J, wherein, 0.35 ≥ K / (F + J) ≥ 0.

08.

11. The rotor structure according to claim 1, characterized in that, The end face of the main hole body (41) on the side close to the outer peripheral surface of the rotor core (1) is arranged in parallel with the outer peripheral surface of the rotor core (1) and the distance therebetween is P, and the width of the motor air gap of the motor formed by the rotor structure is δ; wherein, 1.7 ≥ P / δ ≥ 0.

4.

12. The rotor structure according to claim 1, characterized in that, The included angle between the projection of the first branch hole (42) on the predetermined plane and the projection of the second hole segment on the predetermined plane is L, wherein, 140° ≥ L ≥ 45°.

13. The rotor structure according to claim 12, characterized in that, The included angle between the projection of the second branch hole (43) on the predetermined plane and the projection of the first hole segment on the predetermined plane is M; wherein, L = M.

14. An electrode, 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 13.

15. A compressor, comprising a motor, characterized in that, The motor is the motor according to claim 14.

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