CN111711293A - Rotor structure, motor and compressor - Google Patents

Abstract

The invention mainly aims to provide a rotor structure, a motor and a compressor, wherein the rotor structure comprises a rotor core and a plurality of permanent magnets arranged on the rotor core so as to form a plurality of magnetic poles on the rotor core, and the plurality of magnetic poles comprise a plurality of N poles and a plurality of S poles which are 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 comprises 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 two opposite sides of the main hole body; the projection of the main hole body on the predetermined plane is strip-shaped, the extension direction of the main hole body is arranged in a circumferential crossing mode with the rotor core, the projections of the first branch hole and the second branch hole on the predetermined plane are strip-shaped, and the central lines of the first branch hole and the second branch hole in the extension direction are connected with the middle of the main hole body. Through the arrangement of the invention, the problem of high vibration noise of the motor in the prior art is solved.

Description

Rotor structure, motor and compressor

Technical Field

The invention relates to the field of motors, in particular to a rotor structure, a motor and a compressor.

Background

In recent years, with the development of permanent magnet material manufacturing technology and the rapid reduction of cost, the permanent magnet motor has excellent performance and low price, the technical development of the permanent magnet motor is greatly promoted, the permanent magnet material resources are rich, and the technical research and development of the permanent magnet motor are promoted.

The permanent magnet motor generates a main magnetic field by a permanent magnet, and compared with a common induction motor, the permanent magnet synchronous motor does not need reactive exciting current, and the rotor resistance loss is zero in a synchronous running state. Therefore, the power factor is high and the efficiency is high, and the power factor can be used for replacing an induction motor with lower force energy index, the economic benefit and the social benefit are very obvious, and the power factor is widely applied to various industries.

However, the magnetic energy product of the permanent magnet material of the permanent magnet synchronous motor, the fixed mark and the permanent magnet of the material is not changed, the air gap magnetic field of the motor is difficult to adjust, the tooth space structure of the motor enables the air gap magnetic density and the counter electromotive force to have higher harmonic content, and the peak value of the electromagnetic force density of the motor is large, so that the torque pulsation and the vibration noise of the motor are larger.

Disclosure of Invention

The invention mainly aims to provide a rotor structure, a motor and a compressor, and aims to solve the problem that the motor in the prior art is high in vibration noise.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a rotor structure 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 including a plurality of N poles and a plurality of S poles alternately disposed in a 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 comprises 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 two opposite sides of the main hole body; the projection of the main hole body on the predetermined plane is strip-shaped, the extension direction of the main hole body is arranged in a circumferential crossing mode with the rotor core, the projections of the first branch hole and the second branch hole on the predetermined plane are strip-shaped, and the central lines of the first branch hole and the second branch hole in the extension direction are connected with the middle of the main hole body.

Further, the projection of the first branch hole and the second branch hole on the predetermined plane is perpendicular to the projection of the main hole body on the predetermined plane; and/or the projection of the main hole body on a 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 positioned on the same straight line.

Further, on the predetermined plane, one end of the first branch hole is connected with 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 with 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.

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 is more than or equal to B.

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 is more than or equal to 4.6 and more than or equal to 1.5.

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 preset plane is C; wherein, 0.5 is more than or equal to C/(A + B + C) is more than or equal to 0.1.

Furthermore, each magnetic pole is provided with a plurality of magnetism isolating holes which are arranged in pairs; the two magnetic isolation holes in pairs are symmetrically arranged relative to the center line of the magnetic pole of the corresponding magnetic pole.

Further, the minimum distance between two magnetism isolating holes in a pair is E, the minimum distance between each magnetism isolating hole and a permanent magnet which is located on one side of the corresponding magnetic pole and close to the magnetism isolating hole is D, and the thickness of the permanent magnet is F; wherein 5.8 is not less than (D + E)/F is not less than 1.5.

Further, the two magnetism isolating holes in the pair are arranged at intervals, so that an intermediate magnetic bridge is formed between the two magnetism isolating holes in the pair.

Furthermore, the main hole bodies of the two paired magnetism isolating holes are arranged in parallel, the distance is G, and the minimum distance between the two paired magnetism isolating holes is E; wherein, E/G is more than or equal to 0.6 and more than or equal to 0.2.

Further, the projection of each main hole body on the predetermined plane is inclined to the magnetic pole center line of the corresponding magnetic pole; the included angle between the main hole bodies of the two paired magnetism isolating holes is N, and the included angle between the permanent magnets positioned on the two sides of the magnetic pole is O; wherein N/O is more than or equal to 0.5 and more than or equal to 0.03.

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 J/H is more than or equal to 0.4 and more than or equal to 0.05.

Furthermore, the minimum distance between the magnetism isolating hole and the permanent magnet which is located on one side of the corresponding magnetic pole and close to the magnetism isolating hole is K, the thickness of the permanent magnet is F, the length of the projection of the main hole body on the preset plane is J, and the K/(F + J) is more than or equal to 0.35 and more than or equal to 0.08.

Furthermore, the end face of one side of the main hole body close to the peripheral surface of the rotor core is arranged in parallel with the peripheral surface of the rotor core at a distance of P, and the width of a motor air gap of the motor formed by the rotor structure is P; wherein, 1.7 is more than or equal to P/morethan or equal to 0.4.

Furthermore, along the direction far away from the axis of the rotor core, the main hole body comprises a first hole section and a second hole section, and the first hole section and the second hole section are respectively positioned at two sides of the first branch hole; wherein, the included angle between the projection of the first branch hole on the preset plane and the projection of the second hole section on the preset plane is L, wherein, 140 degrees and more than or equal to L and more than or equal to 45 degrees.

Furthermore, an included angle between the projection of the second branch hole on the preset plane and the projection of the first hole section on the preset plane is M; wherein L ═ M.

According to a second aspect of the present invention there is provided an electrode comprising a stator structure and a rotor structure, the rotor structure being as described above.

According to a third aspect of the present invention, there is provided a compressor comprising a motor, the motor being the above-mentioned motor.

The invention provides a rotor structure with a rotor core, a plurality of permanent magnets and magnetism isolating holes, wherein the permanent magnets are uniformly distributed on the rotor core around the axis of the rotor core to form a plurality of magnetic poles comprising an N pole and an S pole, and the magnetism isolating holes are formed in at least one magnetic pole. The magnetic isolation hole comprises 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 two opposite sides of the main hole body. The plane of the axis of the rotor core is used as a preset plane, the projections of the main hole body, the first branch holes and the second branch holes on the preset plane are all in a strip shape, the extending direction of the main hole body and the circumferential direction of the rotor core are arranged in a crossed mode, the central lines of the extending directions of the first branch holes and the second branch holes are connected with the main hole body and are located at positions close to the middle section of the main hole body, and therefore the width of the magnetism isolating holes in the circumferential direction and the radial direction of the rotor core 1 is changed in a gradient mode, namely the size of the magnetism isolating holes in the radial direction and the circumferential direction of the rotor core is changed in a gradient mode, and meanwhile the size and the shape of the magnetism isolating holes in the axial direction of the rotor core are unchanged. By the technical scheme provided by the invention, the technical effects of effectively improving the magnetic resistance distribution of each part of the magnetic circuit of the motor, improving the magnetic flux trend, adjusting the air gap magnetic field distribution, improving the air gap flux density waveform, reducing the cogging effect of the motor, reducing the counter electromotive force harmonic ratio of the motor, reducing the torque pulsation of the motor, reducing the electromagnetic force density peak value of the motor and reducing the electromagnetic vibration noise of the motor are achieved, and the problem of larger vibration noise of the motor in the prior art is solved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 shows a schematic structural view of a rotor structure according to a first embodiment of the present invention;

FIG. 2 shows a schematic view of the magnetic flux profile of the rotor structure shown in FIG. 1;

fig. 3 shows a schematic structural view of a rotor structure according to a second embodiment of the present invention;

fig. 4 shows a schematic structural view of a rotor structure according to a third embodiment of the present invention;

fig. 5 shows a schematic structural view of a rotor structure according to a fourth embodiment of the present invention;

fig. 6 shows a schematic structural view of a rotor structure according to a fifth embodiment of the present invention;

FIG. 7 illustrates a graph comparing measured torque ripple of a prior art motor with a motor of the present application;

FIG. 8 shows a comparison of measured back emf harmonic ratios for a prior art motor versus a motor of the present application;

FIG. 9 is a graph comparing measured peak electromagnetic force densities for a prior art motor and a motor of the present application; and

fig. 10 shows a graph comparing the measured total noise values for a compressor with a prior art motor and a compressor with a motor of the present application.

Wherein the figures include the following reference numerals:

1. a rotor core; 2. a permanent magnet; 3. a magnetic pole; 31. a magnetic pole centerline; 4. a magnetism isolating hole; 41. a main bore body; 42. a first branch hole; 43. a second branch hole; 5. a middle magnetic bridge; 6. a magnetic isolation bridge; 7. a magnetic conductive path; 71. a first path region; 72. a second path region; 73. a third path region.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1 to 6, the present invention provides a rotor structure including 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 disposed along a 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 comprises 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 two opposite sides of the main hole body 41; the plane perpendicular to the axis of the rotor core 1 is used as a predetermined plane, the projection of the main hole body 41 on the predetermined plane is in a bar shape, the extending direction of the main hole body is intersected 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 in a bar shape, and the central lines along the extending direction of the first branch hole and the second branch hole are connected with the middle part of the main hole body 41.

The invention provides a rotor structure with a rotor core 1, a plurality of permanent magnets 2 and magnetism isolating holes 4, wherein the permanent magnets 2 are uniformly distributed on the rotor core 1 around the axis of the rotor core 1 to form a plurality of magnetic poles 3, the magnetic poles comprise an N pole and an S pole, and the magnetism isolating holes 4 are formed in at least one magnetic pole 3. The magnetism isolating 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 disposed on opposite sides of the main hole body 41. The plane perpendicular to the axis of the rotor core 1 is taken as a predetermined plane, the projections of the main hole body 41, the first branch holes 42 and the second branch holes 43 on the predetermined plane are all in a strip shape, the extending direction of the main hole body 41 is arranged in a circumferential direction of the rotor core 1 in a crossed manner, the central lines of the extending directions of the first branch holes 42 and the second branch holes 43 are connected with the main hole body 41 and are located at positions close to the middle section of the main hole body 41, so that the widths of the magnetism isolating holes 4 in the circumferential direction and the radial direction of the rotor core 1 are changed in a gradient manner, namely, the sizes of the magnetism isolating holes 4 in the radial direction and the circumferential direction of the rotor core 1 are changed in a gradient manner, and meanwhile, the sizes and the shapes of the magnetism isolating holes 4 in the axis direction of the rotor core 1 are unchanged. By the technical scheme provided by the invention, the technical effects of effectively improving the magnetic resistance distribution of each part of the magnetic circuit of the motor, improving the magnetic flux trend, adjusting the air gap magnetic field distribution, improving the air gap flux density waveform, reducing the cogging effect of the motor, reducing the counter electromotive force harmonic ratio of the motor, reducing the torque pulsation of the motor, reducing the electromagnetic force density peak value of the motor and reducing the electromagnetic vibration noise of the motor are achieved, and the problem of larger vibration noise of the motor in the prior art is solved.

Specifically, rotor core 1 is a material having strong magnetic permeability, which makes magnetic resistance of rotor core 1 small. Alternatively, the rotor core 1 is formed by stacking a plurality of silicon steel sheets, which allows magnetic lines of force to easily pass through. Because the magnetism isolating holes 4 are filled with air and other non-magnetic materials, the magnetic conductivity is poor, the magnetic resistance is large, and magnetic lines of force are not easy to pass through, the magnetism isolating holes 4 are formed, the magnetic resistance distribution of all parts of a magnetic circuit of the motor rotor structure can be changed, the trend of the magnetic lines of force in the rotor structure is changed, and the air gap flux density waveform is improved, so that the counter potential harmonic ratio is reduced, the motor torque pulsation is reduced, the electromagnetic force amplitude is reduced, and the electromagnetic vibration noise of the motor is reduced.

As shown in fig. 2, for the magnetic flux trend diagram of the rotor structure of the embodiment provided by the invention, the lines with arrows are the marks of the magnetic lines, the solid lines with arrows indicate that more magnetic lines pass through the position, and the dotted lines with arrows indicate that less magnetic lines pass through the position. As is apparent from fig. 2, the magnetic lines of force pass through the magnetic shielding holes 4 less, and the magnetic shielding holes 4 provided by the present invention effectively improve the distribution of the magnetic lines of force of the rotor structure.

As shown in fig. 1, the projection of the first branch hole 42 and the second branch hole 43 on the predetermined plane is perpendicular to the projection of the main aperture body 41 on the predetermined plane; and/or the projection of the main aperture body 41 on a predetermined plane extends in the radial direction of the rotor core 1 or 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.

As shown in fig. 1 to 6, on a 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 toward the permanent magnet 2 near the first branch hole 42; and/or 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 toward the magnetic pole center line 31 of the corresponding magnetic pole 3 on a predetermined plane.

The rotor structure provided by the invention adopts the magnetic isolation holes 4 with the cross-shaped structure, and the magnetic isolation holes 4 not only have main hole bodies 41 extending along the radial direction of the rotor core 1, namely main parts of the magnetic isolation holes 4, but also have first branch holes 42 and second branch holes 43 extending along the circumferential direction of the rotor.

The heads of the first branch hole 42 and the second branch hole 43 extend from the same position of the main part of the magnetism isolating hole 4 close to the middle part, and the magnetic resistance of the heads of the first branch hole 42 and the second branch hole 43 is large because the heads of the first branch hole 42 and the second branch hole 43 are communicated with the main part of the magnetism isolating hole 4; 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, so that the shape of the magnetism isolating hole 4 is in a cross-shaped structure with two narrow ends and a wide middle part along the direction far away from the axis of the rotor core 1, and the widths of the magnetism isolating hole 4 along the circumferential direction and the radial direction of the rotor core 1 have gradient changes. Make rotor core's circumference magnetic resistance inequality everywhere, this and stator tooth's socket cooperation for magnetic circuit magnetic conductance everywhere is more even when the motor operation, and then has improved the air gap magnetic field distribution of motor, has reduced the air gap flux density wave form of motor, has reduced the torque ripple of motor, has reduced the back electromotive force harmonic of motor and has accounted for the ratio, and has reduced the electromagnetic force density peak value of motor and the vibration noise of motor.

As shown in fig. 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 B; wherein A is more than or equal to B.

Preferably, the projection of the first branch hole 42 on the predetermined plane has a length a, and the projection of the second branch hole 43 on the predetermined plane has a length B; wherein, A/B is more than or equal to 4.6 and more than or equal to 1.5.

Projections of the first branch holes 42 and the second branch holes 43 on a predetermined plane are in a bar shape, and a length a of the projection of the first branch holes 42 on the predetermined plane is a width thereof 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 thereof in the circumferential direction of the rotor core 1.

First branch hole 42 is greater than the width of second branch hole 43 in rotor core 1's circumferential direction at rotor core 1's circumferential direction, when the value setting of AB is in 1.5 to 4.6 within ranges, can be when guaranteeing that middle magnetic bridge 5 between two second branch holes 43 of same magnetic pole 3 can not be too short, make first branch hole 42 be close to permanent magnet 2 more, in order to change the magnetic flux trend that permanent magnet 2 sent, improve air gap magnetic density waveform, and then reduced the vibration noise of motor, and the output torque of motor has been guaranteed.

As shown in fig. 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 B; the width of the projection of the main hole body 41 on the predetermined plane is C; wherein, 0.5 is more than or equal to C/(A + B + C) is more than or equal to 0.1.

The width C of the projection on the predetermined plane of the trunk portion of the magnetism isolating hole 4 (i.e., the main hole body 41) is the width thereof in the circumferential direction of the rotor core 1. Along rotor core 1's radial direction, separate the width of magnetism hole 4 in rotor core 1's circumferential direction and be both ends narrow, can guarantee that rotor core provides sufficient iron core magnetic conduction route, and the centre is wide, can change the magnetic flux trend.

When the value of C/(A + B + C) is set within the range of 0.1 to 0.5, the magnetic flux trend can be effectively changed, the magnetic density distribution at the magnetic isolation holes 4 of the cross-shaped structure, namely the surrounding magnetic density distribution is improved, the air gap magnetic density waveform is optimized, and the electromagnetic force density peak value of the motor and the vibration noise of the motor are reduced.

As shown in fig. 1 to 6, each magnetic pole 3 has a plurality of magnetism isolating holes 4, and the plurality of magnetism isolating holes 4 are provided in pairs; the paired two magnetism isolating holes 4 are disposed symmetrically with respect to the magnetic pole center line 31 of the corresponding magnetic pole 3.

As shown in fig. 1, the minimum distance between two magnetism isolating holes 4 in a pair is E, the minimum distance between each magnetism isolating hole 4 and the permanent magnet 2 which is located at one side of the corresponding magnetic pole 3 and close to the magnetism isolating hole 4 is D, and the thickness of the permanent magnet 2 is F; wherein 5.8 is not less than (D + E)/F is not less than 1.5.

At least two cross-shaped magnetic isolation holes 4 are formed in each magnetic pole 3, the two magnetic isolation holes 4 are symmetrically arranged relative to a magnetic pole center line 31, a distance is reserved between the two magnetic isolation holes 4, the distance between the second branch holes 43 of the two magnetic isolation holes 4 is E, a distance is reserved between the first branch holes 42 of the two magnetic isolation holes 4 and the two permanent magnets 2, the distance is D, and the thickness of each permanent magnet is F.

Each magnetic pole 3 of the rotor structure is provided with three magnetic conduction paths 7, a distance is reserved between two second branch holes 43 to allow magnetic flux to pass through, the distance is reserved between two first branch holes 42 and the permanent magnet 2 close to the two first branch holes, the distance is reserved between the two first branch holes 42 and the permanent magnet 2 close to the two first branch holes, the magnetic resistance of the three magnetic conduction paths 7 is small to allow the magnetic flux to pass through, non-magnetic conduction substances such as air are arranged in the magnetic isolation holes 4, the magnetic resistance is large, and only a small part of magnetic flux can pass through.

When the value of (D + E)/F is set to be in the range of 1.5 to 5.8, the magnetic flux at each magnetic conduction path 7 can be effectively improved, the air gap flux density waveform of the motor is further improved, the torque pulsation of the motor is reduced, and the electromagnetic force density peak value of the motor and the electromagnetic vibration noise of the motor are reduced.

As shown in fig. 1, the two magnetism isolating holes 4 in a pair are spaced apart from each other, so that an intermediate magnetic bridge is formed between the two magnetism isolating holes 4 in a pair.

A distance is reserved between two magnetism isolating holes 4 which are arranged in pairs on each magnetic pole 3, so that the width of a middle magnetic bridge 5 between the two magnetism isolating holes 4 along the circumferential direction of the rotor core 1 has gradient change, the width of the magnetism isolating holes 4 changes to be wide-narrow-wide along the axial direction far away from the rotor core 1, the width of the middle part of the middle magnetic bridge 5 along the circumferential direction of the rotor core 1 is smaller, and the conducted magnetic flux at the middle magnetic bridge 5 is reduced; the width of the two ends of the middle magnetic bridge 5 along the circumferential direction of the rotor core 1 is larger, and the magnetic flux at the middle magnetic bridge 5 is not too small. Meanwhile, the width of the outer peripheral surface of the middle magnetic bridge 5 close to the rotor core 1 is larger, namely the width of the outer peripheral surface of the middle magnetic bridge close to the air gap side is larger, so that the corresponding air gap flux density distribution of the middle magnetic bridge 5 is further improved, the air gap flux density waveform is improved, the harmonic wave is reduced, and the electromagnetic force density peak value of the motor and the electromagnetic vibration noise of the motor are reduced.

As shown in fig. 1, the main hole bodies 41 of the two magnetism isolating holes 4 in the pair are arranged in parallel and have a distance G, and the minimum distance between the two magnetism isolating holes 4 in the pair is E; wherein, E/G is more than or equal to 0.6 and more than or equal to 0.2.

A middle magnetic bridge 5 is arranged between the two magnetic isolation holes 4 which are arranged in pairs, and the distance G between the main hole bodies 41 of the two magnetic isolation holes 4 is the width of the two ends of the middle magnetic bridge 5 along the circumferential direction of the rotor core 1; the minimum distance E between 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 intermediate magnetic bridge 5 in the circumferential direction of the rotor core 1. Since the main hole bodies 41 of the two magnetism isolating holes 4 are parallel to each other, the width of the end of the intermediate magnetic bridge 5 near the axis of the rotor core 1 is equal to the width of the end of the intermediate magnetic bridge 5 near the outer peripheral surface of the rotor core 1, and the width is G.

When the value of E/G is set in the range of 0.2-0.6, the sine degree of the air gap flux density waveform is optimal, the peak value of the electromagnetic force density of the motor is lowest, and the vibration noise of the motor is also lowest.

As shown in fig. 5 and 6, the projection of each main hole body 41 on the predetermined plane is inclined 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 paired magnetism isolating holes 4 is N, and the included angle between the permanent magnets 2 positioned on the two sides of the magnetic pole 3 is O; wherein N/O is more than or equal to 0.5 and more than or equal to 0.03.

The main hole bodies 41 of the two magnetism isolating holes 4 (i.e. the main parts of the magnetism isolating holes 4) of each magnetic pole 3, which are symmetrically arranged about the magnetic pole center line 31, are inclined relative to the magnetic pole center line 31, a certain angle exists between the main parts of the two magnetism isolating holes 4, the angle is N, the angle between the two permanent magnets 2 of each magnetic pole 3 is O, and 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 magnets 2 along the trend of the magnetic pole 3, so that the magnetic flux density of each area of the magnetic pole 3 is influenced.

When the value of N/O is set in the range of 0.03 to 0.5, the main part of the magnetism isolating hole 4 guides the magnetic flux trend to be optimal, so that the magnetic conductance of each part of a magnetic circuit is more uniform, the air gap flux density waveform is improved, the torque pulsation of the motor is reduced, and the electromagnetic force density peak value of the motor and the vibration noise of the motor are reduced.

As shown in fig. 1, 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 J/H is more than or equal to 0.4 and more than or equal to 0.05.

The projections of the first branch holes 42 and the main hole body 41 (i.e. the main part of the magnetism isolating hole 4) on the predetermined plane are both in a bar shape, and the width H of the projection of the first branch holes 42 on the predetermined plane is the length of the first branch holes in the radial direction of the rotor core 1; the length J of the projection of the main hole body 41 on the predetermined plane is the length thereof in the radial direction of the rotor core 1.

The length of the first branch hole 42 in the radial direction of the rotor core 1 is smaller than the length of the main portion of the magnetism isolating hole 4 in the radial direction of the rotor core 1, and since the first branch hole 42 extends in the circumferential direction of the rotor core 1, the transmission of the magnetic flux generated by the permanent magnet 2 to the air gap is hindered, the longer the length of the first branch hole 42 in the radial direction of the rotor core 1 is, the larger the magnetic resistance of the first branch hole 42 is, the stronger the ability of the first branch hole to block the conduction of the magnetic flux is, and therefore, the overlong the radial direction of the rotor core 1 of the first branch hole 42 can reduce the output torque of the motor.

When the value of J/H is set in the range of 0.05 to 0.4, the output torque of the motor can be ensured, the peak value of the electromagnetic force density of the motor can be minimized, and the vibration noise of the motor can be minimized.

As shown in FIG. 1, the minimum distance between the magnetism isolating hole 4 and the permanent magnet 2 which is located at one side of the corresponding magnetic pole 3 and close to the magnetism isolating 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.

The projection of the main part (namely the main hole body 41) of the magnetism isolating hole 4 on a preset plane is in a strip shape, a certain distance is reserved between the main part of the magnetism isolating hole 4 and the permanent magnet 2, and the distance is K; the thickness of the permanent magnet 2 is F; the length of the trunk of the magnetism isolating hole 4 is J.

Magnetic flux is allowed to pass between the trunk part of the magnetism isolating hole 4 and the permanent magnet 2, so that part of the magnetic flux on one side of the permanent magnet 2 close to the axis of the rotor core 1 passes from the third path area 73 of the magnetic conduction path 7 at the middle magnetic bridge 5 to the outer peripheral surface of the rotor core 1, and part of the magnetic flux passes from the first path area 71 and the second path area 72 of the magnetic conduction path 7 on two sides of the magnetic pole 3 to the outer peripheral surface of the rotor core 1; the stem of the magnet-isolating hole 4 is filled with a non-magnetic material such as air, which prevents the magnetic flux from passing therethrough.

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

Preferably, the end surface of the main hole body 41 close to one side of the outer circumferential surface of the rotor core 1 is parallel to the outer circumferential surface of the rotor core 1 and has a distance P, and the width of the motor air gap of the motor formed by the rotor structure is P; wherein, 1.7 is more than or equal to P/morethan or equal to 0.4.

The width of a motor air gap of the motor formed by the rotor structure is a gap between a rotor and a stator of the motor, and the air gap flux density refers to the magnetic induction intensity of a magnetic field existing in the air gap. The distance P between the side wall of the main hole body 41 close to the outer circumferential surface of the rotor core 1 and the outer circumferential surface of the rotor core 1 is the magnetic isolation bridge 6, and the magnetic isolation bridge 6 allows a part of the magnetic force to be transmitted to the air gap. The width of the magnetic isolation bridge 6 in the radial direction of the rotor core 1 is uniform and consistent along the circumferential direction of the rotor core 1, when the value of P/is set to be in the range of 0.4 to 1.7, the magnetic flux transmitted at the magnetic isolation bridge 6 is optimal, the air gap flux density waveform is optimally improved, the peak value of the electromagnetic force density of the motor is the lowest, and the vibration noise of the motor is the lowest.

As shown in fig. 3 and 4, in 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, which are respectively located on both sides of the first branch hole 42; wherein, the included angle between the projection of the first branch hole 42 on the predetermined plane and the projection of the second hole section on the predetermined plane is L, wherein, 140 degrees and L are more than or equal to 45 degrees.

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 in a bar shape, and a certain angle is formed between the first branch hole 42 and the second hole section, and the angle is L. When the value of L is in the range of 45-140 degrees, the first branch hole 42 is closer to the permanent magnet 2, the magnetic flux density in different magnetic conduction path 7 regions can be improved, and the air gap magnetic density waveform is improved, so that the torque pulsation of the motor is reduced, and the electromagnetic force density peak value of the motor and the vibration noise of the motor are reduced.

As shown in fig. 3 and 4, the projection of the second branch hole 43 on the predetermined plane and the projection of the first hole section on the predetermined plane form an angle M; wherein L ═ M.

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 in a bar shape, and a certain angle is formed between the second branch hole 43 and the first hole section, and the angle is M. When angle equals between second branch hole 43 and the first hole section with angle between first branch hole 42 and the second hole section, L is when M promptly, first branch hole 42 is more nearly apart from one side that permanent magnet 2 is close to the rotor core axis, second branch hole 43 is farther apart from one side that permanent magnet 2 is close to the rotor core axis, this makes the magnetic conductance everywhere of the magnetic circuit of the circumferential direction of rotor core 1 and radial direction more even, thereby the sine degree of air gap flux density waveform has been improved, the motor harmonic has been reduced, and the electromagnetic noise that the harmonic arouses has been reduced.

The invention also provides an electrode which comprises a stator structure and a rotor structure, wherein the rotor structure is the rotor structure. Thus, the vibration noise of the motor can be reduced.

The invention also provides a compressor, which comprises the motor. Thus, the vibration noise of the compressor can be reduced.

As shown in fig. 7, which is a comparison graph of the measured torque ripple of the prior art motor and the motor of the present application, it is apparent from fig. 7 that the range of the torque ripple of the motor of the present application is much smaller than that of the prior art motor.

As shown in fig. 8, in comparison with the measured back emf harmonic ratios of the prior art motor and the present motor, it is evident from fig. 8 that the back emf harmonic ratio of the present motor is much smaller than that of the prior art motor.

As shown in fig. 9, which is a comparison graph of the measured peak values of the electromagnetic force densities of the conventional motor and the motor of the present application, it is apparent from fig. 9 that the peak value of the electromagnetic force density of the motor of the present application is much smaller than that of the conventional motor.

As shown in fig. 10, which is a comparison graph of the measured total noise values of the compressor having the conventional motor and the compressor having the motor of the present application, it is apparent in fig. 10 that the total noise value of the compressor having the motor of the present application is much smaller than that of the compressor having the conventional motor.

The rotor structure of the invention comprises a rotor iron core 1 and a permanent magnet 2. Permanent magnet 2 sets up in the permanent magnet groove on rotor core 1, and permanent magnet 2 on the rotor has formed the N utmost point and the S utmost point of alternate distribution, has seted up on rotor core 1 ' S magnetic pole 3 and has separated magnetic hole 4, separates magnetic hole 4 existing main hole body 41 along rotor core 1 ' S radial direction extension, separates the trunk portion of magnetic hole 4 promptly, has first branch hole 42 and the second branch hole 43 along rotor core 1 ' S circumferential direction extension again. Wherein, first branch hole 42 and second branch hole 43 all connect in main hole body 41, and be located the position department that is close to main hole body 41 middle section, the extending direction of first branch hole 42 and second branch hole 43 is on a straight line, first branch hole 42 is located the one side that is close to permanent magnet 2, second branch hole 43 is located the one side that is close to magnetic pole central line 31, this makes magnetic isolation hole 4 all have the change of gradient along rotor core 1's circumference and radial direction's width, along rotor core 1's radial direction and circumferential direction, magnetic isolation hole 4 both ends are narrow, the centre is wide, the shape is like "ten" font structure.

The permanent magnet motor depends on the permanent magnet 2 to generate a main magnetic field, and the permanent magnet motor has the advantages of high air gap magnetic density, high working efficiency, small volume, high power density, simple structure and high reliability, and is widely applied to various industries. However, in the permanent magnet synchronous motor, the magnetic energy product of the permanent magnet 2 made of the fixed-grade material is unchanged, the difficulty in adjusting the air gap magnetic field of the motor is high, and meanwhile, the tooth space structure of the motor enables the air gap magnetic density and the counter electromotive force to have high harmonic content and the peak value of the electromagnetic force density of the motor to be large, so that the torque pulsation and the vibration noise of the motor are high.

The rotor core 1 is provided with the magnetic isolation holes 4 in the cross-shaped structure, so that the magnetic resistance distribution of magnetic circuits at all positions of the motor is changed, the cogging effect of the motor is reduced, the torque pulsation of the motor is reduced, the air gap magnetic density waveform is improved, the counter potential harmonic ratio of the motor is reduced, the electromagnetic force density peak value of the motor is reduced, the technical effect of reducing the electromagnetic vibration noise of the motor is achieved, and the problems of large air gap magnetic density, high counter potential waveform distortion rate, large counter potential harmonic ratio, large motor torque pulsation, large motor electromagnetic force, large motor vibration and large noise of the permanent magnet synchronous motor are solved.

The invention provides a rotor structure with a rotor core 1, a plurality of permanent magnets 2 and magnetism isolating holes 4, wherein the permanent magnets 2 are uniformly distributed on the rotor core 1 around the axis of the rotor core 1 to form a plurality of magnetic poles 3, the magnetic poles comprise an N pole and an S pole, and the magnetism isolating holes 4 are formed in at least one magnetic pole 3. The magnetism isolating 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 disposed on opposite sides of the main hole body 41. The plane perpendicular to the axis of the rotor core 1 is taken as a predetermined plane, the projections of the main hole body 41, the first branch holes 42 and the second branch holes 43 on the predetermined plane are all in a strip shape, the extending direction of the main hole body 41 is arranged in a circumferential direction of the rotor core 1 in a crossed manner, the central lines of the extending directions of the first branch holes 42 and the second branch holes 43 are connected with the main hole body 41 and are located at positions close to the middle section of the main hole body 41, so that the widths of the magnetism isolating holes 4 in the circumferential direction and the radial direction of the rotor core 1 are changed in a gradient manner, namely, the sizes of the magnetism isolating holes 4 in the radial direction and the circumferential direction of the rotor core 1 are changed in a gradient manner, and meanwhile, the sizes and the shapes of the magnetism isolating holes 4 in the axis direction of the rotor core 1 are unchanged. By the technical scheme provided by the invention, the technical effects of effectively improving the magnetic resistance distribution of each part of the magnetic circuit of the motor, improving the magnetic flux trend, adjusting the air gap magnetic field distribution, improving the air gap flux density waveform, reducing the cogging effect of the motor, reducing the counter electromotive force harmonic ratio of the motor, reducing the torque pulsation of the motor, reducing the electromagnetic force density peak value of the motor and reducing the electromagnetic vibration noise of the motor are achieved, and the problem of larger vibration noise of the motor in the prior art is solved.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (18)

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) comprising a plurality of N poles and a plurality of S poles alternately disposed in a circumferential direction of the rotor core (1); it is characterized in that the preparation method is characterized in that,

at least one magnetic pole (3) of the rotor core (1) is provided with a magnetic isolation hole (4), the magnetic isolation hole (4) comprises 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 two opposite sides of the main hole body (41);

the plane perpendicular to the axis of the rotor core (1) is used as a preset plane, the projection of the main hole body (41) on the preset plane is in a strip shape, the extending direction of the main hole body and the circumferential direction of the rotor core (1) are arranged in a crossed mode, the projections of the first branch hole (42) and the second branch hole (43) on the preset plane are in the strip shape, and the central line of the first branch hole and the central line of the second branch hole along the extending direction are connected with the middle of the main hole body (41).

2. The rotor structure of claim 1,

the projection of the first branch hole (42) and the second branch hole (43) on the predetermined plane is 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 iron core (1) or is parallel to a magnetic pole central 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 of claim 1,

one end of the first branch hole (42) is connected with the middle of the main hole body (41) on the predetermined plane, and the other end of the first branch hole (42) extends toward the permanent magnet (2) close to the first branch hole (42); and/or

One end of the second branch hole (43) is connected to a middle portion of the main hole body (41) on the predetermined plane, and the other end of the second branch hole (43) extends toward a magnetic pole center line (31) of the corresponding magnetic pole (3).

4. The rotor structure according to claim 1, characterized in that the projection of the first branch hole (42) on the predetermined plane has a length a and the projection of the second branch hole (43) on the predetermined plane has a length B; wherein A is more than or equal to B.

5. The rotor structure according to claim 1, characterized in that the projection of the first branch hole (42) on the predetermined plane has a length a and the projection of the second branch hole (43) on the predetermined plane has a length B; wherein, A/B is more than or equal to 4.6 and more than or equal to 1.5.

6. The rotor structure according to claim 1, characterized in that the projection of the first branch hole (42) on the predetermined plane has a length a and the projection of the second branch hole (43) on the predetermined plane has a length B; the projection width of the main hole body (41) on the predetermined plane is C; wherein, 0.5 is more than or equal to C/(A + B + C) is more than or equal to 0.1.

7. The rotor structure according to claim 1, characterized in that each of the magnetic poles (3) has a plurality of the magnetism isolating holes (4), the plurality of magnetism isolating holes (4) being provided in pairs; the two magnetism isolating holes (4) in pairs are symmetrically arranged relative to the magnetic pole center line (31) of the corresponding magnetic pole (3).

8. The rotor structure according to claim 7, characterized in that the minimum distance between two said flux barriers (4) in a pair is E, the minimum distance between each said flux barrier (4) and the permanent magnet (2) located on one side of the corresponding said pole (3) and close to the flux barrier (4) is D, the thickness of the permanent magnet (2) is F; wherein 5.8 is not less than (D + E)/F is not less than 1.5.

9. The rotor structure according to claim 7, characterized in that the two magnet-isolating holes (4) in a pair are spaced apart from each other so that an intermediate magnetic bridge is formed between the two magnet-isolating holes (4) in a pair.

10. The rotor structure according to claim 7, characterized in that the main bore bodies (41) of two said flux barriers (4) in a pair are arranged in parallel and at a distance G, the minimum distance between two said flux barriers (4) in a pair being E; wherein, E/G is more than or equal to 0.6 and more than or equal to 0.2.

11. The rotor structure according to claim 7, characterized in that the projection of each of the main bore bodies (41) on the predetermined plane is inclined to a pole center line (31) of the corresponding pole (3); an included angle between main hole bodies (41) of the two paired magnetism isolating holes (4) is N, and an included angle between the permanent magnets (2) positioned on two sides of the magnetic pole (3) is O; wherein N/O is more than or equal to 0.5 and more than or equal to 0.03.

12. The rotor structure according to claim 1, characterized in that the projection of the first branch hole (42) on the predetermined plane has a width H, and the projection of the main hole body (41) on the predetermined plane has a length J; wherein J/H is more than or equal to 0.4 and more than or equal to 0.05.

13. The rotor structure according to claim 1, characterized in that the minimum distance between the magnetism isolating hole (4) and the permanent magnet (2) located at one side of the corresponding magnetic pole (3) and close to the magnetism isolating hole (4) is K, the thickness of the permanent magnet (2) is F, 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.

14. The rotor structure according to claim 1, wherein an end surface of the main hole body (41) on a side close to the outer circumferential surface of the rotor core (1) is arranged in parallel with the outer circumferential surface of the rotor core (1) at a distance P, and the rotor structure forms a motor air gap of a motor having a width P; wherein, 1.7 is more than or equal to P/morethan or equal to 0.4.

15. The rotor structure according to claim 1, characterized in that the main bore body (41) includes a first bore section and a second bore section, which are located on both sides of the first branch bore (42), respectively, in a direction away from the axis of the rotor core (1); wherein an included angle between the projection of the first branch hole (42) on the predetermined plane and the projection of the second hole section on the predetermined plane is L, wherein 140 DEG ≧ L ≧ 45 °.

16. A rotor structure according to claim 15, characterised in that the projection of the second branch bore (43) onto the predetermined plane and the projection of the first bore section onto the predetermined plane are at an angle M; wherein L ═ M.

17. An electrode comprising a stator structure and a rotor structure, wherein the rotor structure is as claimed in any one of claims 1 to 16.

18. A compressor comprising an electric motor, wherein the electric motor is the electric motor of claim 17.

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