CN115549332A

CN115549332A - Motor and compressor

Info

Publication number: CN115549332A
Application number: CN202110732293.2A
Authority: CN
Inventors: 孙洁; 赖英乾
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2021-06-29
Filing date: 2021-06-29
Publication date: 2022-12-30

Abstract

The invention relates to a motor and a compressor, which comprise a motor shell, a stator core, a stator winding and a rotor core, wherein the stator core is connected in the motor shell; the peripheral surface of the rotor core comprises a plurality of sub-dividing surfaces which are connected end to end, each sub-dividing surface comprises a first arc surface, a second arc surface and a first smooth transition surface which connects the first arc surface and the second arc surface, two adjacent sub-dividing surfaces are connected through a second smooth transition surface, and the first smooth transition surface and the second smooth transition surface are both located on the inner side of at least one of the first arc surface and the second arc surface in the radial direction. According to the motor, the peripheral surface of the rotor core is in a specific shape different from the peripheral surface, so that the cogging torque can be weakened, the rotation speed fluctuation of the motor can be avoided, and the vibration and electromagnetic noise generated by the motor can be effectively reduced.

Description

Motor and compressor

Technical Field

The invention belongs to the technical field of compressors, and particularly relates to a motor and a compressor.

Background

The compressor is a driven fluid machine that raises low-pressure gas to high-pressure gas, and is the heart of a refrigeration system. The refrigerating cycle is powered by sucking low-temperature and low-pressure refrigerant gas from the air suction pipe, driving the piston to compress the refrigerant gas through the operation of the motor, and discharging high-temperature and high-pressure refrigerant gas to the exhaust pipe. Along with the improvement of various performance requirements of the compressor, the motor of the compressor is urgently required to operate under the working condition of high rotating speed and heavy load. However, the existing various compressor motors are difficult to realize large-load operation at high rotating speed, the compressor motor vibrates greatly, the generated electromagnetic Noise also causes high Noise of the compressor during operation, the use requirements of the compressor on high efficiency and low Noise are not facilitated, and the performance of NVH (English abbreviation of Noise, vibration and Harshness) of an automobile is further deteriorated when the compressor is installed on the automobile.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the motor and the compressor are provided aiming at the problem that the electromagnetic noise generated by the motor of the compressor in the prior art causes high noise when the compressor works.

In order to solve the technical problem, an embodiment of the present invention provides a motor, including a motor housing, a stator core, a stator winding, and a rotor core, where the stator core is connected in the motor housing, the rotor core is disposed in a central hole of the stator core, the stator core is provided with a plurality of stator slots spaced from each other around the rotor core, and the stator winding is disposed in the stator slots;

the rotor core is provided with a plurality of permanent magnet mounting grooves, the permanent magnet mounting grooves extend along the axial direction of the rotor core and penetrate through the rotor core, the permanent magnet mounting grooves are arranged around the rotor core and are spaced from one another in the circumferential direction, and permanent magnets are embedded in the permanent magnet mounting grooves;

the peripheral surface of the rotor core comprises a plurality of sub-dividing surfaces which are connected end to end, each sub-dividing surface comprises a first arc surface, a second arc surface and a first smooth transition surface which connects the first arc surface and the second arc surface, two adjacent sub-dividing surfaces are connected through a second smooth transition surface, the first smooth transition surface and the second smooth transition surface are both located on the inner side of at least one of the first arc surface and the second arc surface in the radial direction, and the first arc surface is arranged corresponding to the permanent magnet mounting groove.

Optionally, the first arc surface and the second arc surface are eccentrically arranged, a center of the first arc surface is located on a radial outer side of a center of the second arc surface, an eccentricity range of the first arc surface and the second arc surface is 3mm to 3.5mm, the first arc surface is closer to a central axis of the rotor core than the second arc surface, and the first smooth transition surface and the second smooth transition surface are both located on an inner side of the second arc surface and on an outer side of the first arc surface in a radial direction.

Optionally, the first arc surface and the second arc surface are concentrically arranged.

Optionally, the first circular arc surface and the second circular arc surface have the same radius, the first smooth transition surface and the second smooth transition surface are both curved surfaces that are recessed toward the center of the rotor core, and the first smooth transition surface and the second smooth transition surface are both located on the inner side of the first circular arc surface and on the inner side of the second circular arc surface in the radial direction.

Optionally, the permanent magnet mounting groove is a V-shaped groove with an opening facing the outer peripheral surface of the rotor core, the V-shaped groove includes a first sub-groove and a second sub-groove, the outer end of the first sub-groove and the outer end of the second sub-groove face the outer peripheral surface of the rotor core, a first magnetic isolation bridge is formed between the outer end of the first sub-groove and the outer peripheral surface of the rotor core, a second magnetic isolation bridge is formed between the outer end of the second sub-groove and the outer peripheral surface of the rotor core, the inner end of the first sub-groove and the inner end of the second sub-groove are opposite at an interval to form a third magnetic isolation bridge therebetween, and the permanent magnets are embedded in both the first sub-groove and the second sub-groove of the V-shaped groove; the interval between the adjacent V-shaped grooves is larger than the width of the third magnetism isolating bridge; the first arc surface is positioned in the opening of the corresponding V-shaped groove.

Optionally, the permanent magnet is a rectangular magnetic steel, a magnetic isolation gap is arranged between a groove wall of the first sub-groove, which is located on the inner side of the opening of the V-shaped groove, and the permanent magnet, and a magnetic leakage gap is arranged between a groove wall of the first sub-groove, which is located on the outer side of the opening of the V-shaped groove, and the permanent magnet; the second sub-groove is located the inboard cell wall of opening in V-arrangement groove with be equipped with between the permanent magnet and separate the magnetic gap, the second sub-groove is located the cell wall in the opening outside in V-arrangement groove with be equipped with the magnetic leakage clearance between the permanent magnet.

Optionally, the width of an air gap between the stator core and the rotor core is 0.85mm to 0.95mm, an included angle formed by the first subslot and the second subslot ranges from 130 degrees to 150 degrees, the width of the third magnetic isolation bridge is 0.5mm to 1.2mm, a spacing distance between the adjacent V-shaped grooves is not less than 2.4mm, the width of the first magnetic isolation bridge is 0.5mm to 1.5mm, and the width of the second magnetic isolation bridge is 0.5mm to 1.5mm.

Optionally, 9 stator slots are formed in the stator core, and two stator windings are arranged in each stator slot; the rotor core is provided with 6 permanent magnet mounting grooves, and the peripheral surface of the rotor core comprises 6 sub-division surfaces.

Optionally, a triangular through hole far away from the outer circumferential surface of the rotor core is arranged between the adjacent permanent magnet mounting grooves of the rotor core, and the triangular through hole extends along the axial direction of the rotor core and penetrates through the rotor core; the rotor core is provided with an oval through hole on one side, close to the central axis of the rotor core, of the middle part of the permanent magnet mounting groove, and the oval through hole extends along the axial direction of the rotor core and penetrates through the rotor core; the rotor core comprises a plurality of layers of electromagnetic steel plates, the electromagnetic steel plates are connected in a laminated mode, a plurality of spaced circular holes are formed in the rotor core around the central axis of the rotor core, and rivets are arranged in all or part of the circular holes to fix the electromagnetic steel plates in the laminated direction.

According to the motor provided by the embodiment of the invention, the outer peripheral surface of the rotor core can present a specific shape different from the circumferential surface due to the smooth connection of the first arc surface, the second arc surface, the first smooth transition surface and the second smooth transition surface, and the specific shape can weaken the cogging torque determined by the mechanical structure of the motor when the motor works, avoid the occurrence of the rotation speed fluctuation of the motor, and effectively reduce the vibration and the electromagnetic noise generated by the motor, so that the noise and the vibration of the compressor can be reduced when the compressor works. In addition, the specific shape of the peripheral surface of the rotor core enables the distribution of air gap magnetic density between the rotor core and the stator core to be optimized, and the air gap magnetic flux can better approach a sine waveform by utilizing a non-uniform air gap, so that harmonic waves are reduced when a motor works, and the use requirements of high efficiency and low noise of a compressor are facilitated.

On the other hand, an embodiment of the present invention provides a compressor, including the above-mentioned motor and a refrigerant, where the refrigerant flows through the stator core and an air gap between the stator core and the rotor core.

Drawings

Fig. 1 is a schematic cross-sectional structure diagram of a motor provided by a first embodiment of the invention;

fig. 2 is a schematic cross-sectional structure view of a rotor core of an electric machine according to a first embodiment of the present invention;

fig. 3 is a schematic structural view of an outer peripheral surface of a rotor core of a motor according to a first embodiment of the present invention;

fig. 4 is a schematic view of a motor according to a first embodiment of the present invention, in which a permanent magnet is embedded in a second subslot;

fig. 5 is a schematic structural view of an outer peripheral surface of a rotor core of a motor according to a second embodiment of the present invention.

The reference numerals in the specification are as follows:

1. a motor housing;

2. a stator core; 21. a central bore; 22. a stator slot;

3. a stator winding;

4. a rotor core; 41. a permanent magnet mounting groove; 411. a first subslot; 412. a second subslot; 42. sub-dividing the surface; 421. a first arc surface; 422. a second arc surface; 423. a first smooth transition surface; 424. a second smooth transition surface; 43. a first magnetic isolation bridge; 44. a second magnetic isolation bridge; 45. a third magnetic isolation bridge; 46. a triangular through hole; 47. an elliptical through hole; 48. a circular hole;

5. a permanent magnet; 51. a magnetic isolation gap; 52. and a magnetic leakage gap.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

First embodiment

As shown in fig. 1 to 4, a motor according to a first embodiment of the present invention includes a motor housing 1, a stator core 2, a stator winding 3, and a rotor core 4, wherein the stator core 2 is connected in the motor housing 1, the rotor core 4 is disposed in a central hole 21 of the stator core 2, the stator core 2 is provided with a plurality of stator slots 22 spaced apart from each other around the rotor core 4, and the stator winding 3 is disposed in the stator slots 22.

Be equipped with a plurality of permanent magnet mounting grooves 41 on rotor core 4, permanent magnet mounting groove 41 is followed rotor core 4's axial extension and run through rotor core 4, it is a plurality of permanent magnet mounting groove 41 encircles rotor core 4 sets up and separates each other on the circumferencial direction, permanent magnet 5 is embedded to be equipped with in permanent magnet mounting groove 41.

The outer peripheral surface of the rotor core 4 includes a plurality of sub-divided surfaces 42 connected end to end, each sub-divided surface 42 includes a first arc surface 421, a second arc surface 422, and a first smooth transition surface 423 connecting the first arc surface 421 and the second arc surface 422, two adjacent sub-divided surfaces 42 are connected by a second smooth transition surface 424, the first smooth transition surface 423 and the second smooth transition surface 424 are both located on the inner side of at least one of the first arc surface 421 and the second arc surface 422 in the radial direction, and the first arc surface 421 is disposed corresponding to the permanent magnet mounting groove 41.

In the first embodiment, as shown in fig. 3, the first arc surface 421 and the second arc surface 422 are eccentrically disposed, the center of the first arc surface 421 is located radially outside the center of the second arc surface 422, the eccentricity between the first arc surface 421 and the second arc surface 422 is in a range of 3mm to 3.5mm, the first arc surface 421 is closer to the central axis of the rotor core 4 than the second arc surface 422, and both the first smooth transition surface 423 and the second smooth transition surface 424 are located radially inside the second arc surface 422 and outside the first arc surface 421. The central axis of the interval part between the adjacent permanent magnet mounting grooves 41 is the q axis, and the central axis of the single permanent magnet mounting groove 41 is the d axis. The outer peripheral surface of the rotor core 4 has the smallest air gap at the q-axis position, so that the q-axis magnetic flux can be increased, and the q-axis inductance is reduced; the air gap of the peripheral surface of the rotor core 4 is the largest at the d-axis, so that the d-axis magnetic flux can be reduced, and the d-axis inductance is increased; thereby increasing the saliency ratio and increasing the reluctance torque.

In the first embodiment, the permanent magnet mounting groove 41 is a V-shaped groove that opens toward the outer circumferential surface of the rotor core 4, the V-shaped groove includes a first sub-groove 411 and a second sub-groove 412, an outer end of the first sub-groove 411 and an outer end of the second sub-groove 412 face the outer circumferential surface of the rotor core 4, a first magnetic isolation bridge 43 is formed between the outer end of the first sub-groove 411 and the outer circumferential surface of the rotor core 4, a second magnetic isolation bridge 44 is formed between the outer end of the second sub-groove 412 and the outer circumferential surface of the rotor core 4, an inner end of the first sub-groove 411 and an inner end of the second sub-groove 412 are opposed to each other at a distance to form a third magnetic isolation bridge 45 therebetween, and the permanent magnets 5 are embedded in the first sub-groove 411 and the second sub-groove 412 of the V-shaped groove; the interval between the adjacent V-shaped grooves is larger than the width of the third magnetic isolation bridge 45; the first arc surface 421 is located in the opening of the corresponding V-shaped groove.

The permanent magnet 5 is embedded in the first subslot 421 and the second subslot 422 of the V-shaped groove, and the interval between the adjacent V-shaped grooves is greater than the width of the third magnetic isolation bridge 45, so that the q-axis magnetic circuit reluctance is reduced, lq is increased, d-axis magnetic circuit reluctance is increased, and Ld is reduced, thereby increasing the salient pole ratio; an increase in the saliency ratio results in an increase in the reluctance torque, and thus in an increase in the total torque of the machine. Meanwhile, because the reluctance torque is increased, the current value and the magnetic flux in the rotor core 4 are reduced, and the purpose of weakening the magnetic field and increasing the speed can be achieved. Therefore, the motor can realize heavy-load operation at high rotating speed so as to meet the requirement of the compressor.

In a first embodiment, as shown in fig. 4, the permanent magnet 5 is a rectangular magnetic steel, a magnetic isolation gap is provided between a groove wall of the first sub-groove 421 located inside the opening of the V-shaped groove and the permanent magnet 5, and a magnetic leakage gap is provided between a groove wall of the first sub-groove 421 located outside the opening of the V-shaped groove and the permanent magnet 5; the second subslot 422 is located the inboard cell wall of the opening of V-arrangement groove with be equipped with between the permanent magnet 5 and separate magnetic gap 51, the second subslot 422 is located the cell wall in the opening outside of V-arrangement groove with be equipped with magnetic leakage clearance 52 between the permanent magnet 5. Through reasonable setting magnetic isolation gap and magnetic leakage gap, can control the inductance ratio of magnetic leakage and increase q axle and d axle, and then increase the reluctance torque of motor improves the ability of the motor weak magnetism speed extension, thereby improves the performance of motor. Preferably, the permanent magnet 5 is magnetic steel made of N42SH material.

In the first embodiment, the width of the air gap between the stator core 2 and the rotor core 4 is 0.85mm to 0.95mm, and the outer circumferential surface of the rotor core 4 is the smallest in the q-axis air gap and the largest in the d-axis air gap. The included angle formed by the first subslot 421 and the second subslot 422 is theta, the range of theta is 130-150 degrees, the spacing distance between the adjacent V-shaped grooves is L, L is not less than 2.4mm, the ranges of theta and L can ensure that a q-axis magnetic circuit space is smooth, and a salient pole is large. The width of the first magnetic isolation bridge 43 is h, the range of h is 0.5mm-1.5mm, the width of the second magnetic isolation bridge 44 is 0.5mm-1.5mm, the width of the third magnetic isolation bridge 45 is b, the range of b is 0.5mm-1.2mm, and the ranges of b and h can ensure that the leakage of magnetic flux is remarkably reduced on the premise that the mechanical structure strength of the rotor core 4 is not influenced, and the reduction of torque caused by magnetic leakage flux can be effectively inhibited.

In the first embodiment, as shown in fig. 1-2, 9 stator slots 22 are provided on the stator core 2, and two stator windings 3 are provided in each stator slot 22; the rotor core 4 is provided with 6 permanent magnet mounting grooves 41, and the outer peripheral surface of the rotor core 4 includes 6 sub-division surfaces 42.

In the first embodiment, as shown in fig. 1-2, the rotor core 4 is provided with a triangular through hole 46 which is far from the outer peripheral surface of the rotor core 4 between the adjacent permanent magnet mounting grooves 41, the triangular through hole 46 extends in the axial direction of the rotor core 4 and penetrates through the rotor core 4, and the triangular through hole 46 can reduce the weight of the rotor core 4 and guide a magnetic circuit without affecting a q-axis magnetic circuit; the rotor core 4 is provided with an oval through hole 47 at a side of the middle part of the permanent magnet mounting groove 41 close to the central axis of the rotor core 4, the oval through hole 47 extends along the axial direction of the rotor core 4 and penetrates through the rotor core 4, and the oval through hole 47 can reduce the weight of the rotor core 4 and guide a magnetic circuit without affecting a d-axis magnetic circuit; the rotor core 4 includes a plurality of stacked electromagnetic steel plates, the plurality of stacked electromagnetic steel plates are connected, the rotor core 4 is provided with a plurality of spaced circular holes 48 around a central axis thereof, and rivets are provided in all or a part of the circular holes 48 to fix the plurality of stacked electromagnetic steel plates in a stacking direction.

In the motor provided by the first embodiment of the present invention, the outer peripheral surface of the rotor core may have a specific shape different from the circumferential surface due to the smooth connection of the first arc surface, the second arc surface, the first smooth transition surface, and the second smooth transition surface, and this specific shape may weaken a cogging torque determined by a mechanical structure of the motor when the motor is in operation, avoid a rotation speed fluctuation of the motor, and effectively reduce vibration and electromagnetic noise generated by the motor, so that noise and vibration of the compressor during operation may be reduced. In addition, the specific shape of the peripheral surface of the rotor core enables the distribution of the air gap magnetic density between the rotor core and the stator core to be optimized, and the air gap magnetic flux can be better close to a sine waveform by utilizing a non-uniform air gap, so that harmonic waves are reduced when the motor works, and the use requirements of high efficiency and low noise of the compressor are met.

Second embodiment

Referring to fig. 5, a motor according to a second embodiment of the present invention is different from the motor according to the first embodiment in that the first circular arc surface 421 and the second circular arc surface 422 are concentrically arranged, the first circular arc surface 421 and the second circular arc surface 422 have the same radius, the first smooth transition surface 423 and the second smooth transition surface 424 are both curved surfaces that are recessed toward the center of the rotor core 4, and the first smooth transition surface 423 and the second smooth transition surface 424 are both located radially inside the first circular arc surface 421 and radially inside the second circular arc surface 422.

In some other embodiments, the first arc surface and the second arc surface have different radii, and the first smooth transition surface and the second smooth transition surface are both disposed such that a portion thereof is located between the first arc surface and the second arc surface and another portion thereof is located inside one of the first smooth transition surface and the second smooth transition surface.

Third embodiment

A third embodiment of the present invention provides a compressor, which includes the motor and the refrigerant of the above embodiments, wherein the refrigerant flows through the stator core and an air gap between the stator core and the rotor core.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A motor is characterized by comprising a motor shell, a stator core, a stator winding and a rotor core, wherein the stator core is connected in the motor shell, the rotor core is arranged in a central hole of the stator core, the stator core is provided with a plurality of stator slots which are mutually spaced and surround the rotor core, and the stator winding is arranged in the stator slots;

the rotor core is provided with a plurality of permanent magnet mounting grooves, the permanent magnet mounting grooves extend along the axial direction of the rotor core and penetrate through the rotor core, the permanent magnet mounting grooves are arranged around the rotor core and are spaced from each other in the circumferential direction, and permanent magnets are embedded in the permanent magnet mounting grooves;

2. The electric machine of claim 1, wherein the first arc surface is disposed eccentrically from the second arc surface, a center of the first arc surface is located radially outward of a center of the second arc surface, an eccentricity of the first arc surface from the second arc surface ranges from 3mm to 3.5mm, the first arc surface is closer to a central axis of the rotor core than the second arc surface, and both the first smooth transition surface and the second smooth transition surface are located radially inward of the second arc surface and outward of the first arc surface.

3. The electric machine of claim 1 wherein the first arcuate surface is concentrically disposed with the second arcuate surface.

4. The electric machine of claim 3, wherein the first arc surface and the second arc surface have the same radius, and wherein the first smooth transition surface and the second smooth transition surface are both curved surfaces that are recessed toward the center of the rotor core, and wherein the first smooth transition surface and the second smooth transition surface are both located radially inward of the first arc surface and radially inward of the second arc surface.

5. The motor according to claim 1, wherein the permanent magnet mounting groove is a V-shaped groove that opens toward the outer circumferential surface of the rotor core, the V-shaped groove includes a first sub-groove and a second sub-groove, an outer end of the first sub-groove and an outer end of the second sub-groove face the outer circumferential surface of the rotor core, a first magnetic isolation bridge is formed between the outer end of the first sub-groove and the outer circumferential surface of the rotor core, a second magnetic isolation bridge is formed between the outer end of the second sub-groove and the outer circumferential surface of the rotor core, an inner end of the first sub-groove and an inner end of the second sub-groove are opposite to each other at a distance to form a third magnetic isolation bridge therebetween, and the permanent magnets are embedded in both the first sub-groove and the second sub-groove of the V-shaped groove; the interval between the adjacent V-shaped grooves is larger than the width of the third magnetism isolating bridge; the first arc surface is positioned in the opening of the corresponding V-shaped groove.

6. The motor of claim 5, wherein the permanent magnet is a rectangular magnetic steel, a magnetic isolation gap is arranged between the permanent magnet and the wall of the first subslot inside the opening of the V-shaped groove, and a magnetic leakage gap is arranged between the permanent magnet and the wall of the first subslot outside the opening of the V-shaped groove; the second sub-groove is located the inboard cell wall of the opening in V-arrangement groove with be equipped with between the permanent magnet and separate the magnetic gap, the second sub-groove is located the cell wall in the opening outside in V-arrangement groove with be equipped with the magnetic leakage clearance between the permanent magnet.

7. The motor of claim 5, wherein the width of an air gap between the stator core and the rotor core is 0.85mm-0.95mm, the included angle formed by the first subslot and the second subslot is in the range of 130 ° -150 °, the width of the third magnetic isolation bridge is 0.5mm-1.2mm, the spacing distance between the adjacent V-shaped grooves is not less than 2.4mm, the width of the first magnetic isolation bridge is 0.5mm-1.5mm, and the width of the second magnetic isolation bridge is 0.5mm-1.5mm.

8. The electric machine of claim 1, wherein said stator core is provided with 9 of said stator slots, two of said stator windings being provided in each of said stator slots; the rotor core is provided with 6 permanent magnet mounting grooves, and the peripheral surface of the rotor core comprises 6 sub-division surfaces.

9. The motor according to claim 1, wherein the rotor core is provided with a triangular through hole between the adjacent permanent magnet mounting grooves, the triangular through hole being far from the outer circumferential surface of the rotor core, the triangular through hole extending in the axial direction of the rotor core and penetrating through the rotor core; the rotor core is provided with an oval through hole on one side, close to the central axis of the rotor core, of the middle part of the permanent magnet mounting groove, and the oval through hole extends along the axial direction of the rotor core and penetrates through the rotor core; the rotor core comprises a plurality of layers of electromagnetic steel plates which are connected in a laminated mode, a plurality of spaced circular holes are formed in the rotor core in a surrounding mode of the central axis of the rotor core, and rivets are arranged in all or part of the circular holes to fix the plurality of layers of electromagnetic steel plates in the laminated direction.

10. A compressor comprising the motor according to any one of claims 1 to 9 and a refrigerant, the refrigerant flowing through the stator core and an air gap between the stator core and the rotor core.