Motors and compressors

Abstract

The present invention relates to a motor and a compressor, comprising a motor housing, a stator core, a stator winding and a rotor core, wherein the stator core is connected to the motor housing, the rotor core is arranged in the central hole of the stator core, the stator core is provided with a plurality of mutually spaced stator slots around the rotor core, and the stator winding is arranged in the stator slots; the outer peripheral surface of the rotor core comprises a plurality of sub-dividing surfaces connected end to end, the sub-dividing surfaces comprise a first arc surface, a second arc surface and a first smooth transition surface connecting the first arc surface and the second arc surface, two adjacent sub-dividing surfaces are connected by a second smooth transition surface, and the first smooth transition surface and the second smooth transition surface are both radially located on the inner side of at least one of the first arc surface and the second arc surface. In the motor of the present invention, the outer peripheral surface of the rotor core presents a specific shape different from the circumferential surface, which can weaken the cogging torque, avoid the speed fluctuation of the motor, and effectively reduce the vibration and electromagnetic noise generated by the motor.

Description

Technical Field

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

[0002] The compressor is a driven fluid machine that can elevate low-pressure gas to high-pressure gas. It is the heart of the refrigeration system. It inhales low-temperature, low-pressure refrigerant gas from the intake pipe, compresses it by driving the piston through the operation of the motor, and then discharges high-temperature, high-pressure refrigerant gas to the exhaust pipe to provide power for the refrigeration cycle. With the improvement of various performance requirements for compressors, there is an urgent need for the compressor motor to be able to operate under high-speed and high-load conditions. However, various existing compressor motors are difficult to achieve high-load operation at high speeds, and the vibration of the compressor motor is large. The electromagnetic noise generated also makes the compressor very noisy when it is working, which is not conducive to the high-efficiency and low-noise use requirements of the compressor. When the compressor is installed on a car, it will further cause the NVH (noise, vibration and harshness) performance of the car to deteriorate. Summary of the invention

[0003] The technical problem to be solved by the present invention is: to provide a motor and a compressor in view of the problem in the prior art that the electromagnetic noise generated by the compressor motor makes the compressor very noisy when working.

[0004] To solve the above technical problems, an embodiment of the present invention provides a motor, comprising a motor housing, a stator core, a stator winding and a rotor core, wherein the stator core is connected to the motor housing, the rotor core is arranged 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 arranged in the stator slots;

[0005] The rotor core is provided with a plurality of permanent magnet mounting grooves, the permanent magnet mounting grooves extending along the axial direction of the rotor core and penetrating the rotor core, the plurality of permanent magnet mounting grooves are arranged around the rotor core and spaced from each other in the circumferential direction, and permanent magnets are embedded in the permanent magnet mounting grooves;

[0006] The outer peripheral surface of the rotor core includes a plurality of sub-dividing surfaces connected end to end, the sub-dividing surfaces include a first arc surface, a second arc surface and a first smooth transition surface connecting the first arc surface and the second arc surface, two adjacent sub-dividing surfaces are connected by 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.

[0007] Optionally, the first arc surface is eccentrically arranged with respect to the second arc surface, the center of the first arc surface is located radially outside the center of the second arc surface, the eccentricity range between the first arc surface and the second arc surface is 3mm-3.5mm, the first arc surface is closer to the 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 radially inside the second arc surface and outside the first arc surface.

[0008] Optionally, the first arc surface and the second arc surface are arranged concentrically.

[0009] Optionally, the radii of the first arc surface and the second arc surface are equal, the first smooth transition surface and the second smooth transition surface are both curved surfaces 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 arc surface and the inner side of the second arc surface in the radial direction.

[0010] Optionally, the permanent magnet mounting groove is a V-shaped groove with an opening toward the outer circumferential 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 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, the inner end of the first sub-groove and the inner end of the second sub-groove are spaced relative to each other to form a third magnetic isolation bridge therebetween, the permanent magnets are embedded in the first sub-groove and the second sub-groove of the V-shaped groove; the interval between adjacent V-grooves is greater than the width of the third magnetic isolation bridge; the first arc surface is located in the corresponding opening of the V-shaped groove.

[0011] Optionally, the permanent magnet is a rectangular magnetic steel, and a magnetic isolation gap is provided between the groove wall of the first sub-groove located on the inner side of the opening of the V-shaped groove and the permanent magnet, and a magnetic leakage gap is provided between the groove wall of the first sub-groove located on the outer side of the opening of the V-shaped groove and the permanent magnet; a magnetic isolation gap is provided between the groove wall of the second sub-groove located on the inner side of the opening of the V-shaped groove and the permanent magnet, and a magnetic leakage gap is provided between the groove wall of the second sub-groove located on the outer side of the opening of the V-shaped groove and the permanent magnet.

[0012] Optionally, the air gap width between the stator core and the rotor core is 0.85mm-0.95mm, the angle formed by the first sub-slot and the second sub-slot is in the range of 130°-150°, the width of the third magnetic isolation bridge is 0.5mm-1.2mm, the spacing distance between 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.

[0013] Optionally, the stator core is provided with 9 stator slots, each of which is provided with two stator windings; the rotor core is provided with 6 permanent magnet mounting slots, and the outer peripheral surface of the rotor core includes 6 sub-dividing surfaces.

[0014] Optionally, the rotor core is provided with a triangular through hole away from the outer circumferential surface of the rotor core between adjacent permanent magnet mounting slots, and the triangular through hole extends along the axial direction of the rotor core and passes through the rotor core; the rotor core is provided with an elliptical through hole on one side of the middle part of the permanent magnet mounting slot close to the central axis of the rotor core, and the elliptical through hole extends along the axial direction of the rotor core and passes through the rotor core; the rotor core includes multiple layers of electromagnetic steel plates, the multiple layers of electromagnetic steel plates are stacked and connected, and the rotor core is provided with a plurality of spaced circular holes around its own central axis, and rivets are provided in all or part of the circular holes to fix the multiple layers of electromagnetic steel plates along the stacking direction.

[0015] According to the motor of the embodiment of the present invention, the outer peripheral surface of the rotor core presents a specific shape different from the circumferential surface because the first arc surface, the second arc surface, the first smooth transition surface and the second smooth transition surface are smoothly connected. This specific shape can weaken the tooth slot torque determined by the mechanical structure of the motor when the motor is working, avoid the speed fluctuation of the motor, and effectively reduce the vibration and electromagnetic noise generated by the motor, so that the noise and vibration of the compressor can be reduced when it is working. In addition, this specific shape of the outer peripheral surface of the rotor core optimizes the distribution of the air gap magnetic density between the rotor core and the stator core. The use of a non-uniform air gap can make the air gap flux better approach a sinusoidal waveform, thereby reducing the generation of harmonics when the motor is working, which is conducive to the high efficiency and low noise use requirements of the compressor.

[0016] On the other hand, an embodiment of the present invention provides a compressor, comprising the above-mentioned motor and a refrigerant, wherein the refrigerant flows through the stator core and an air gap between the stator core and the rotor core. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic cross-sectional structural diagram of a motor provided by a first embodiment of the present invention;

[0018] Figure 2 is a schematic diagram of the cross-sectional structure of the rotor core of the motor provided by the first embodiment of the present invention;

[0019] Figure 3 is a schematic structural diagram of the outer peripheral surface of the rotor core of the motor provided by the first embodiment of the present invention;

[0020] Figure 4 is a schematic diagram of a permanent magnet of a motor provided by a first embodiment of the present invention being embedded in a second sub-slot;

[0021] Figure 5 It is a schematic structural diagram of the outer peripheral surface of the rotor core of the motor provided by the second embodiment of the present invention.

[0022] The reference numerals in the specification are as follows:

[0023] 1. Motor housing;

[0024] 2. stator core; 21. center hole; 22. stator slot;

[0025] 3. Stator winding;

[0026] 4. rotor core; 41. permanent magnet mounting slot; 411. first sub-slot; 412. second sub-slot; 42. sub-dividing surface; 421. first arc surface; 422. second arc surface; 423. first smooth transition surface; 424. second smooth transition surface; 43. first magnetic isolation bridge; 44. second magnetic isolation bridge; 45. third magnetic isolation bridge; 46. triangular through hole; 47. elliptical through hole; 48. circular hole;

[0027] 5. Permanent magnet; 51. Magnetic isolation gap; 52. Magnetic leakage gap. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] First embodiment

[0030] like Figure 1-4 As shown, the motor provided by the first embodiment of the present invention includes a motor housing 1, a stator core 2, a stator winding 3 and a rotor core 4, the stator core 2 is connected to the motor housing 1, the rotor core 4 is arranged 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 arranged in the stator slots 22.

[0031] The rotor core 4 is provided with a plurality of permanent magnet mounting grooves 41, which extend along the axial direction of the rotor core 4 and penetrate the rotor core 4. The plurality of permanent magnet mounting grooves 41 are arranged around the rotor core 4 and are spaced apart from each other in the circumferential direction. The permanent magnet mounting grooves 41 are embedded with permanent magnets 5.

[0032] The outer peripheral surface of the rotor core 4 includes a plurality of sub-dividing surfaces 42 connected end to end, and the sub-dividing surfaces 42 include 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-dividing surfaces 42 are connected via a second smooth transition surface 424. The first smooth transition surface 423 and the second smooth transition surface 424 are radially located on the inner side of at least one of the first arc surface 421 and the second arc surface 422. The first arc surface 421 is arranged corresponding to the permanent magnet mounting groove 41.

[0033] In the first embodiment, if Figure 3 As shown, the first arc surface 421 and the second arc surface 422 are eccentrically arranged, the center of the first arc surface 421 is located radially outside the center of the second arc surface 422, the eccentricity range between the first arc surface 421 and the second arc surface 422 is 3mm-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 the first smooth transition surface 423 and the second smooth transition surface 424 are both radially located inside the second arc surface 422 and outside the first arc surface 421. The central axis of the interval between adjacent permanent magnet mounting slots 41 is the q axis, and the central axis of a single permanent magnet mounting slot 41 is the d axis. The outer circumference of the rotor core 4 has the smallest air gap at the q-axis, which can increase the q-axis magnetic flux and reduce the q-axis inductance; the outer circumference of the rotor core 4 has the largest air gap at the d-axis, which can reduce the d-axis magnetic flux and increase the d-axis inductance; thereby increasing the salient pole ratio and the reluctance torque.

[0034] In the first embodiment, the permanent magnet mounting groove 41 is a V-shaped groove with an opening toward the outer peripheral surface of the rotor core 4, and the V-shaped groove includes a first sub-groove 411 and a second sub-groove 412. The outer end of the first sub-groove 411 and the outer end of the second sub-groove 412 face the outer peripheral 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 peripheral surface of the rotor core 4, and a second magnetic isolation bridge 44 is formed between the outer end of the second sub-groove 412 and the outer peripheral surface of the rotor core 4. The inner end of the first sub-groove 411 and the inner end of the second sub-groove 412 are spaced relative to each other to form a third magnetic isolation bridge 45 therebetween, and the permanent magnet 5 is embedded in the first sub-groove 411 and the second sub-groove 412 of the V-shaped groove; the interval between adjacent V-shaped grooves is greater than the width of the third magnetic isolation bridge 45; the first arc surface 421 is located in the corresponding opening of the V-shaped groove.

[0035] The permanent magnet 5 is embedded in the first sub-slot 421 and the second sub-slot 422 of the V-groove. The interval between adjacent V-grooves is greater than the width of the third magnetic isolation bridge 45, which will reduce the magnetic resistance of the q-axis magnetic circuit, and Lq will increase accordingly. The magnetic resistance of the d-axis magnetic circuit will increase, and Ld will decrease accordingly, thereby increasing the salient pole ratio; the increase in the salient pole ratio will lead to an increase in the magnetic resistance torque, thereby increasing the total torque of the motor. At the same time, because the magnetic resistance torque increases, the current value and magnetic flux in the rotor core 4 will decrease, and the purpose of weak magnetic speed increase can also be achieved. Therefore, the motor can achieve high load operation at high speed to meet the needs of the compressor.

[0036] In the first embodiment, if Figure 4 As shown, the permanent magnet 5 is a rectangular magnetic steel, a magnetic isolation gap is provided between the first sub-groove 421 located at the inner side of the opening of the V-shaped groove and the permanent magnet 5, and a magnetic leakage gap is provided between the first sub-groove 421 located at the outer side of the opening of the V-shaped groove and the permanent magnet 5; a magnetic isolation gap 51 is provided between the second sub-groove 422 located at the inner side of the opening of the V-shaped groove and the permanent magnet 5, and a magnetic leakage gap 52 is provided between the second sub-groove 422 located at the outer side of the opening of the V-shaped groove and the permanent magnet 5. By reasonably setting the magnetic isolation gap and the magnetic leakage gap, the magnetic leakage can be controlled and the inductance ratio of the q-axis and the d-axis can be increased, thereby increasing the magnetic resistance torque of the motor, improving the ability of the motor to expand the speed with weak magnetic field, and thus improving the performance of the motor. Preferably, the permanent magnet 5 is a magnetic steel made of N42SH material.

[0037] In the first embodiment, the air gap width between the stator core 2 and the rotor core 4 is 0.85mm-0.95mm, and the outer peripheral surface of the rotor core 4 has the smallest air gap in the q-axis and the largest air gap in the d-axis. The angle formed by the first sub-slot 421 and the second sub-slot 422 is θ, and the range of θ is 130°-150°. The spacing distance between adjacent V-shaped grooves is L, and L is not less than 2.4mm. The range of θ and L can ensure that the q-axis magnetic circuit space is unobstructed and the salient pole is relatively large. The width of the first magnetic isolation bridge 43 is h, and 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, and the range of b is 0.5mm-1.2mm. The range of b and h can ensure that the leakage of magnetic flux is significantly reduced under the premise that the mechanical structural strength of the rotor core 4 is not affected, and the torque reduction caused by the leakage magnetic flux can be effectively suppressed.

[0038] In the first embodiment, if Figure 1-2 As shown, the stator core 2 is provided with 9 stator slots 22 , and each of the stator slots 22 is provided with two stator windings 3 ; the rotor core 4 is provided with 6 permanent magnet mounting slots 41 , and the outer peripheral surface of the rotor core 4 includes 6 sub-dividing surfaces 42 .

[0039] In the first embodiment, if Figure 1-2 As shown, the rotor core 4 is provided with a triangular through hole 46 away from the outer circumferential surface of the rotor core 4 between adjacent permanent magnet mounting grooves 41, and the triangular through hole 46 extends along the axial direction of the rotor core 4 and penetrates the rotor core 4, and the triangular through hole 46 can reduce the weight of the rotor core 4 and guide the magnetic circuit without affecting the q-axis magnetic circuit; the rotor core 4 is provided with an elliptical through hole 47 on one side of the middle part of the permanent magnet mounting groove 41 close to the central axis of the rotor core 4, and the elliptical through hole 47 extends along the axial direction of the rotor core 4 and penetrates the rotor core 4, and the elliptical through hole 47 can reduce the weight of the rotor core 4 and guide the magnetic circuit without affecting the d-axis magnetic circuit; the rotor core 4 includes multiple layers of electromagnetic steel plates, and the multiple layers of electromagnetic steel plates are stacked and connected. The rotor core 4 is provided with a plurality of spaced circular holes 48 around its own central axis, and rivets are arranged in all or part of the circular holes 48 to fix the multiple layers of electromagnetic steel plates in the stacking direction.

[0040] In the motor provided by the first embodiment of the present invention, the outer peripheral surface of the rotor core presents a specific shape different from the circumferential surface because the first arc surface, the second arc surface, the first smooth transition surface and the second smooth transition surface are smoothly connected. This specific shape can weaken the tooth slot torque determined by the mechanical structure of the motor when the motor is working, avoid the speed fluctuation of the motor, and effectively reduce the vibration and electromagnetic noise generated by the motor, so that the noise and vibration of the compressor can be reduced when the compressor is working. In addition, this specific shape of the outer peripheral surface of the rotor core optimizes the distribution of the air gap magnetic density between the rotor core and the stator core, and the use of a non-uniform air gap can make the air gap magnetic flux better approach a sinusoidal waveform, thereby reducing the generation of harmonics when the motor is working, which is conducive to the high efficiency and low noise use requirements of the compressor.

[0041] Second embodiment

[0042] See also Figure 5 The motor provided by the second embodiment of the present invention is different from the first embodiment in that the first arc surface 421 and the second arc surface 422 are concentrically arranged, the radii of the first arc surface 421 and the second arc surface 422 are equal, the first smooth transition surface 423 and the second smooth transition surface 424 are both curved surfaces 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 on the inner side of the first arc surface 421 and the inner side of the second arc surface 422 in the radial direction.

[0043] In some other embodiments, the radii of the first arc surface and the second arc surface are not equal, and the first smooth transition surface and the second smooth transition surface are both configured so that a portion is located between the first arc surface and the second arc surface, and the other portion is located on the inner side of one of the first smooth transition surface and the second smooth transition surface.

[0044] Third embodiment

[0045] A third embodiment of the present invention provides a compressor, which includes the motor of the above embodiment and a refrigerant, wherein the refrigerant flows through the stator core and an air gap between the stator core and the rotor core.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A motor, characterized in that: The motor comprises a motor housing, a stator core, a stator winding and a rotor core, wherein the stator core is connected to the motor housing, the rotor core is arranged 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 arranged in the stator slots; The rotor core is provided with a plurality of permanent magnet mounting grooves, the permanent magnet mounting grooves extending along the axial direction of the rotor core and penetrating the rotor core, the plurality of permanent magnet mounting grooves are arranged around the rotor core and spaced from each other in the circumferential direction, and permanent magnets are embedded in the permanent magnet mounting grooves; The outer peripheral surface of the rotor core includes a plurality of sub-dividing surfaces connected end to end, the sub-dividing surfaces include a first arc surface, a second arc surface and a first smooth transition surface connecting the first arc surface and the second arc surface, two adjacent sub-dividing surfaces are connected by the second smooth transition surface, the first smooth transition surface and the second smooth transition surface are both located radially on the inner side of at least one of the first arc surface and the second arc surface, and the first arc surface is arranged corresponding to the permanent magnet mounting groove; The first arc surface is eccentrically arranged with respect to the second arc surface, the center of the first arc surface is located radially outside the center of the second arc surface, the first arc surface is closer to the 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 radially inside the second arc surface and outside the first arc surface; The central axis of the spacing portion between adjacent permanent magnet installation slots is the q-axis, and the central axis of a single permanent magnet installation slot is the d-axis; The eccentricity between the first arc surface and the second arc surface ranges from 3 mm to 3.5 mm, the angle formed by the first sub-groove and the second sub-groove ranges from 130° to 150°, and the spacing between adjacent V-shaped grooves is not less than 2.4 mm.

2. The motor according to claim 1, characterized in that The permanent magnet mounting groove is a V-shaped groove with an opening toward the outer circumferential surface of the rotor core, and 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 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, and 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. The inner end of the first sub-groove and the inner end of the second sub-groove are spaced relative to each other to form a third magnetic isolation bridge therebetween. The permanent magnets are embedded in the first sub-groove and the second sub-groove of the V-shaped groove; the interval between adjacent V-shaped grooves is greater than the width of the third magnetic isolation bridge; the first arc surface is located in the corresponding opening of the V-shaped groove.

3. The motor according to claim 2, characterized in that The permanent magnet is a rectangular magnetic steel, a magnetic isolation gap is provided between the groove wall of the first sub-groove located on the inner side of the opening of the V-shaped groove and the permanent magnet, and a magnetic leakage gap is provided between the groove wall of the first sub-groove located on the outer side of the opening of the V-shaped groove and the permanent magnet; a magnetic isolation gap is provided between the groove wall of the second sub-groove located on the inner side of the opening of the V-shaped groove and the permanent magnet, and a magnetic leakage gap is provided between the groove wall of the second sub-groove located on the outer side of the opening of the V-shaped groove and the permanent magnet.

4. The motor according to claim 3, characterized in that The width of the air gap between the stator core and the rotor core is 0.85mm-0.95mm, the width of the third magnetic isolation bridge is 0.5mm-1.2mm, 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.

5. The motor according to claim 1, characterized in that The stator core is provided with 9 stator slots, each of which is provided with two stator windings; the rotor core is provided with 6 permanent magnet mounting slots, and the outer peripheral surface of the rotor core includes 6 sub-dividing surfaces.

6. The motor according to claim 1, characterized in that The rotor core is provided with a triangular through hole away from the outer circumferential surface of the rotor core between adjacent permanent magnet mounting grooves, and the triangular through hole extends along the axial direction of the rotor core and penetrates the rotor core; the rotor core is provided with an elliptical through hole on one side of the middle part of the permanent magnet mounting groove close to the central axis of the rotor core, and the elliptical through hole extends along the axial direction of the rotor core and penetrates the rotor core; the rotor core includes multiple layers of electromagnetic steel plates, the multiple layers of electromagnetic steel plates are stacked and connected, and the rotor core is provided with a plurality of spaced circular holes around its own central axis, and rivets are arranged in all or part of the circular holes to fix the multiple layers of electromagnetic steel plates along the stacking direction.

7. A compressor, characterized in that: The motor and the refrigerant include any one of claims 1 to 6, wherein the refrigerant flows through the stator core and the air gap between the stator core and the rotor core.

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