CN221408558U - Motor rotor and permanent magnet synchronous motor - Google Patents

Abstract

The utility model provides a motor rotor and a permanent magnet synchronous motor. The motor rotor comprises a rotor core (4) and permanent magnets (5), wherein permanent magnet grooves (6) are formed in the rotor core (4), the permanent magnets (5) are arranged in the permanent magnet grooves (6), the permanent magnets (5) are magnetized in the radial direction, the polarities of the permanent magnets (5) on one side close to the outer circle of the rotor core (4) are the same, the polarities of the permanent magnets (5) on one side close to the shaft hole of the rotor core (4) are the same, at least two layers of the permanent magnets (5) are arranged in the radial direction under one pole, empty grooves (7) are formed in the rotor core (4) in a still-arranged mode, the empty grooves (7) are single-layer and extend along the circumferential direction of the rotor core (4), the empty grooves (7) and the permanent magnet grooves (6) are alternately distributed along the circumferential direction of the rotor core (4), and each adjacent empty groove (7) and each permanent magnet groove (6) occupy one magnetic pole. According to the motor rotor, d-axis inductance of the motor can be reduced, q-axis inductance of the motor can be increased, and reluctance torque of the motor can be improved.

Description

Motor rotor and permanent magnet synchronous motor

Technical Field

The utility model relates to the technical field of motors, in particular to a motor rotor and a permanent magnet synchronous motor.

Background

The rotor magnetic poles of the alternating pole permanent magnet synchronous motor are alternately arranged by adopting permanent magnets and iron blocks, the magnetizing directions of all the permanent magnets are consistent, and the iron blocks are magnetized into opposite polarities by the adjacent permanent magnets. Compared with the conventional permanent magnet synchronous motor, the alternating pole permanent magnet synchronous motor is simple to manufacture and low in cost, has a good weak magnetic wide speed regulation range, and can also remarkably reduce the use amount of the permanent magnet. The magnetic resistance of the main magnetic circuit is reduced by the permanent magnet grooves and the magnetic resistance introduced by the permanent magnets, so that the effective magnetomotive force is higher, the utilization rate of the permanent magnets is higher, and the air gap flux density which is the same as that of a conventional permanent magnet synchronous motor can be generated even though the consumption of the permanent magnets is reduced. However, the alternating pole permanent magnet synchronous motor has small difference of the inductance of the alternating axis and the direct axis of the special motor rotor, so that the reluctance torque is small.

Disclosure of utility model

The utility model mainly aims to provide a motor rotor and a permanent magnet synchronous motor, which can reduce d-axis inductance of the motor, increase q-axis inductance of the motor and improve reluctance torque of the motor.

In order to achieve the above object, according to an aspect of the present utility model, there is provided a motor rotor, including a rotor core and permanent magnets, wherein permanent magnet slots are provided on the rotor core, the permanent magnets are disposed in the permanent magnet slots, the permanent magnets are radially magnetized, and polarities of the permanent magnets on one side of an outer circle close to the rotor core are the same, the polarities of the permanent magnets on one side of a shaft hole close to the rotor core are the same, at least two layers of permanent magnets are radially arranged under one pole, empty slots are further provided on the rotor core, the empty slots are single-layered and extend along a circumferential direction of the rotor core, the empty slots and the permanent magnet slots are alternately arranged along the circumferential direction of the rotor core, and each of the adjacent empty slots and permanent magnet slots occupies one magnetic pole.

Further, under one pole, the permanent magnet grooves are arranged into at least two layers along the radial direction, the maximum arc angle of the empty groove is alpha 1, and the maximum arc angle of the outer layer permanent magnet groove close to one side of the outer circle of the rotor core is alpha 2, wherein alpha 1 is smaller than alpha 2.

Further, 0.8.ltoreq.α1/α2.ltoreq.0.9.

Further, the radial thickness of the empty slot is A, the permanent magnet slot is two layers, the radial thickness of the permanent magnet slot positioned at the radial inner side is B1, and the radial thickness of the permanent magnet slot positioned at the radial outer side is B2, and A/(B1+B2) is more than or equal to 0.15 and less than or equal to 0.35.

Further, in the cross section perpendicular to the central axis of the rotor core, the empty slot includes a plurality of segments, the plurality of segments are arranged at intervals along the length direction of the empty slot, magnetic bridges are formed between adjacent segments, and the number of the magnetic bridges formed between the segments of the same empty slot is at least three.

Further, the width of the magnetic bridge formed by the segments of the same empty slot increases from the symmetry center line of the empty slot to the two sides.

Further, the rotor core is uniformly divided into a plurality of magnetic pole areas along the circumferential direction by taking the symmetrical center line of the permanent magnet slot as a reference, the symmetrical center line of each magnetic pole area is the uniformly distributed center line of the rotor core, and the symmetrical center line of the empty slot deviates from the uniformly distributed center line of the magnetic pole where the empty slot is positioned.

Further, the offset direction of the symmetry center line of the empty slot with respect to the uniform distribution center line is the rear side of the rotation direction of the rotor core.

Further, the offset angle of the symmetrical center line of the empty slot relative to the uniformly distributed center line is beta, the permanent magnet slots are two layers, and the polar arc included angle between the permanent magnet slots on the same side is beta 1, and beta/beta 1 is more than or equal to 0.9 and less than or equal to 1.1.

Further, β=β1.

According to another aspect of the utility model, there is provided a permanent magnet synchronous motor comprising a motor rotor and a motor stator, wherein the motor rotor is the motor rotor, and the motor rotor is sleeved in the motor stator and forms an air gap with the motor stator.

By applying the technical scheme of the utility model, the motor rotor comprises a rotor core and permanent magnets, wherein the rotor core is provided with permanent magnet grooves, the permanent magnets are arranged in the permanent magnet grooves, the permanent magnets are magnetized in the radial direction, the polarities of the permanent magnets on the side close to the excircle of the rotor core are the same, the polarities of the permanent magnets on the side close to the shaft hole of the rotor core are the same, at least two layers of permanent magnets are arranged in the radial direction under one pole, the rotor core is also provided with empty grooves which are single-layer and extend along the circumferential direction of the rotor core, the empty grooves and the permanent magnet grooves are alternately arranged along the circumferential direction of the rotor core, and each adjacent empty groove and each permanent magnet groove occupy one magnetic pole. The motor rotor adopts the scheme of alternately designing the permanent magnet and the empty slot, solves the problems of asymmetric motor magnetic circuit and abnormal low-order electromagnetic force caused by larger direct-axis magnetic circuit difference of the permanent magnet magnetic pole and the non-permanent magnet magnetic pole of the traditional alternating-pole motor, reduces the output torque pulsation of the motor, ensures that the magnetic field distribution at two sides of one magnetic pole is more symmetrical by the design of the empty slot, and reduces the electromagnetic force generated by the asymmetric magnetic pole; meanwhile, the magnetic force lines of the same permanent magnet can be guided to cover larger polar arcs and are matched with more winding turn chains, so that larger permanent magnet flux links are generated, and larger torque output is obtained; the design of multilayer permanent magnet is adopted, and the magnetic poles formed by the multilayer permanent magnet and the magnetic poles formed by the empty slots are alternately arranged, so that the problem that the reluctance torque is small due to the fact that the alternating-axis inductance and the direct-axis inductance of the motor are not large in a traditional alternating-pole structure motor is solved, the permanent magnet slots are arranged in multiple layers, the q-axis inductance of the motor can be increased, the d-axis inductance of the motor can be reduced through arrangement of the empty slots, the reluctance torque of the motor is improved, meanwhile, the phase difference between the maximum value of the reluctance torque and the maximum value of the permanent magnet torque can be reduced, the peak value of the reluctance torque and the maximum value of the permanent magnet torque are not reduced, and the synthetic torque of the motor is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the utility model. In the drawings:

Fig. 1 shows a schematic structural diagram of a permanent magnet synchronous motor according to an embodiment of the present utility model;

FIG. 2 shows a schematic structural view of a motor rotor according to an embodiment of the present utility model;

FIG. 3 shows a schematic structural view of a motor rotor according to an embodiment of the present utility model;

FIG. 4 shows a schematic structural view of a motor rotor according to an embodiment of the present utility model;

FIG. 5 illustrates a void slot offset block diagram of a motor rotor according to one embodiment of the utility model;

FIG. 6 shows a graph of the α1/α2 ratio of the motor rotor versus the resultant torque of the motor according to an embodiment of the present utility model;

FIG. 7 shows a graph of the ratio A/(B1+B2) of the motor rotor versus the motor resultant torque for an embodiment of the utility model; and

Fig. 8 shows a graph of output torque curves of an electric machine according to an embodiment of the utility model versus a prior art electric machine.

Wherein the above figures include the following reference numerals:

1. A motor stator; 2. a motor rotor; 3. a stator core; 4. a rotor core; 5. a permanent magnet; 6. a permanent magnet slot; 7. a hollow groove; 8. a shaft hole; 9. a magnetic bridge.

Detailed Description

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

The arrow direction in the figure is the direction of rotation of the motor rotor.

Referring to fig. 1 to 8 in combination, according to an embodiment of the present utility model, a motor rotor includes a rotor core 4 and permanent magnets 5, permanent magnet slots 6 are formed in the rotor core 4, the permanent magnets 5 are disposed in the permanent magnet slots 6, the permanent magnets 5 are magnetized radially, and polarities of the permanent magnets 5 on the side close to the outer circle of the rotor core 4 are the same, polarities of the permanent magnets 5 on the side close to a shaft hole 8 of the rotor core 4 are the same, at least two layers of the permanent magnets 5 are arranged radially under one pole, empty slots 7 are also formed in the rotor core 4, the empty slots 7 are single-layered and extend along the circumferential direction of the rotor core 4, the empty slots 7 and the permanent magnet slots 6 are alternately arranged along the circumferential direction of the rotor core 4, and each adjacent empty slot 7 and permanent magnet slot 6 occupy one magnetic pole.

The motor rotor adopts the scheme of alternately designing the permanent magnet 5 and the empty slot 7, solves the problems of asymmetric motor magnetic circuit and abnormal low-order electromagnetic force caused by larger direct-axis magnetic circuit difference of the permanent magnet magnetic poles and the non-permanent magnet magnetic poles of the traditional alternating-pole motor, and the design of the empty slot 7 can ensure that the magnetic field distribution at two sides of one magnetic pole is more symmetric, reduce the electromagnetic force generated by asymmetric magnetic poles, reduce the output torque pulsation of the motor and reduce the vibration noise of the motor; meanwhile, the magnetic force lines of the same permanent magnet 5 can be guided to cover larger polar arcs and are matched with more winding turn chains, so that the magnetic flux leakage of the permanent magnet is reduced, larger magnetic flux links of the permanent magnet 5 are generated, and larger torque output is obtained.

The design of the multilayer permanent magnet 5 is adopted, the magnetic poles formed by the multilayer permanent magnet 5 and the magnetic poles formed by the empty slots 7 are alternately arranged, the problem that the reluctance torque is small due to the fact that the alternating-axis inductance and the direct-axis inductance of the motor are not large in a traditional alternating-pole structure motor is solved, the permanent magnet slots 6 are arranged in multiple layers, the q-axis inductance of the motor can be increased, the d-axis inductance of the motor can be reduced by arranging the empty slots 7, the reluctance torque of the motor is improved, meanwhile, the phase difference between the maximum value of the reluctance torque and the maximum value of the permanent magnet torque can be reduced, the peak value of the reluctance torque and the permanent magnet torque is not reduced, and the synthetic torque of the motor is improved.

In one embodiment, the permanent magnet slots 6 are arranged in at least two layers in the radial direction under one pole, the maximum arc angle of the empty slots 7 is alpha 1, and the maximum arc angle of the outer layer permanent magnet slots 6 near the outer circle side of the rotor core 4 is alpha 2, alpha 1 < alpha 2. The arrangement can improve the utilization rate of the permanent magnet and increase the permanent magnet torque of the motor while improving the reluctance torque.

In one embodiment, 0.8.ltoreq.α1/α2.ltoreq.0.9. In the range, the reluctance torque and the permanent magnet torque of the motor are improved, and the torque is maximum.

Referring to fig. 6, a graph of the relationship between the ratio of α1/α2 of the motor rotor and the resultant torque of the motor according to the embodiment of the present utility model is shown, and it can be seen from the graph that, under the same working condition, when α2 is unchanged, as α1 increases, the resultant torque of the reluctance torque and the permanent magnet torque gradually increases, when α1 increases to a certain extent, the increasing speed of the resultant torque slows down, and when α1/α2 satisfies 0.8++α1/α2++0.9, the reluctance torque and the permanent magnet torque of the motor can be increased while the rotor core space is reasonably utilized, thereby increasing the output torque of the motor.

In one embodiment, the radial thickness of the empty slot 7 is A, the radial thickness of the permanent magnet slot 6 on the radial inner side is B1, the radial thickness of the permanent magnet slot 6 on the radial outer side is B2, and 0.15 is less than or equal to A/(B1+B2) is less than or equal to 0.35. The rotor core 4 can be utilized to the greatest extent, the permanent magnet slots 6 and the empty slots 7 are reasonably arranged, the permanent magnet consumption is reduced, the utilization rate of the permanent magnet is improved, the reluctance torque and the permanent magnet torque of the motor are increased, and the torque output capacity of the motor is improved.

Referring to fig. 7, in the graph of the relation between the ratio of a/(b1+b2) of the motor rotor and the composite torque of the motor according to the embodiment of the utility model, it can be seen from the graph that, under the same working condition, when the thicknesses B1 and B2 of the permanent magnet grooves are unchanged, the composite torque of the reluctance torque and the permanent magnet torque is obviously improved along with the increase of a, when the increase of a is increased to a certain extent, the increasing speed of the composite torque is slowed down, and when the thickness of the permanent magnet groove and the thickness of the empty groove are satisfied with 0.15-0/(b1+b2) -0.35, the permanent magnet torque and the reluctance torque of the motor can be improved while the permanent magnet groove and the empty groove are reasonably arranged, so that the output torque of the motor is improved.

In one embodiment, in a cross section perpendicular to the central axis of the rotor core 4, the hollow slot 7 includes a plurality of segments arranged at intervals along the length direction of the hollow slot 7, magnetic bridges 9 are formed between adjacent segments, and the number of the magnetic bridges 9 formed between the segments of the same hollow slot 7 is at least three. Through making the empty slot 7 form a plurality of segmentation along length direction to make the interval through magnetic bridge 9 between the adjacent segmentation, can utilize magnetic bridge 9 to form the magnetic conduction passageway, reduce the magnetic leakage of permanent magnet 5, promote motor permanent magnet torque.

In one embodiment the width of the magnetic bridge 9 formed by the segments of the same empty slot 7 increases from the symmetry center line of the empty slot 7 to both sides. In the motor rotor, the closer to the permanent magnet 5, the more the distribution of magnetic lines of force is, so that the width distribution of the magnetic bridge 9 can be reasonably optimized, the width of the magnetic bridge 9 at the position close to the permanent magnet 5 is larger, a certain magnetic conduction channel width is ensured, the saturation of a magnetic field near the permanent magnet 5 is avoided, and the permanent magnet torque of the motor is improved.

In one embodiment, the rotor core 4 is uniformly divided into a plurality of magnetic pole areas along the circumferential direction by taking the symmetrical center line of the permanent magnet slot 6 as a reference, wherein the symmetrical center line of each magnetic pole area is the uniformly distributed center line of the rotor core 4, and the symmetrical center line of the empty slot 7 is deviated from the uniformly distributed center line of the magnetic pole where the empty slot 7 is positioned. The phase difference between the maximum values of the reluctance torque and the permanent magnet torque can be reduced so that the resultant torque increases.

In one embodiment, the direction of the offset of the symmetry center line of the empty slots 7 with respect to the uniform distribution center line is the rear side of the rotation direction of the rotor core 4. The arrangement can reduce local saturation of magnetic density and promote the composite output torque of the motor.

In one embodiment, the offset angle of the symmetrical center line of the empty slot 7 relative to the uniformly distributed center line is beta, the permanent magnet slots 6 are two layers, and the polar arc included angle between the permanent magnet slots 6 on the same side is beta 1, and beta/beta 1 is more than or equal to 0.9 and less than or equal to 1.1. The purpose of the arrangement is to reduce the phase difference between the maximum values of the reluctance torque and the permanent magnet torque, ensure that the peak values of the reluctance torque and the permanent magnet torque are not reduced, and improve the composite torque of the motor.

In one embodiment, β=β1, where the resultant torque is the greatest.

Referring to fig. 8 in combination, the output torque curves of the motor according to the present utility model and the motor according to the prior art are compared, and compared with the motor according to the prior art, the motor according to the present utility model has increased output torque, so that the motor efficiency can be improved.

In one embodiment, the magnetic bridges 9 of the same empty slot 7 are symmetrical about the symmetry center line of the empty slot 7, which can further improve the symmetry of the magnetic circuit distribution.

Referring to fig. 1 in combination, a permanent magnet synchronous motor according to an embodiment of the present utility model includes a motor rotor 2 and a motor stator 1, the motor rotor is the motor rotor described above, and the motor rotor 2 is sleeved in the motor stator 1 and forms an air gap with the motor stator 1. The motor stator 1 comprises a stator core 3, a coil is wound on the stator core 3, and the motor stator 1 is matched with a motor rotor through the coil to drive the motor rotor 2 to rotate.

In one embodiment, the motor is a compressor motor for an air conditioner or a direct current fan motor for an air conditioner.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein.

The above description is only of the preferred embodiments of the present utility model and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (11)

1. The utility model provides a motor rotor, its characterized in that includes rotor core (4) and permanent magnet (5), permanent magnet groove (6) have been seted up on rotor core (4), permanent magnet (5) set up in permanent magnet groove (6), permanent magnet (5) radial magnetization, and each permanent magnet (5) are being close to the polarity of the excircle one side of rotor core (4) is the same, permanent magnet (5) are being close to the polarity of shaft hole (8) one side of rotor core (4) is the same, under one pole, permanent magnet (5) radial arrangement is at least two-layer, empty slot (7) have still been seted up on rotor core (4), empty slot (7) are the individual layer, and follow rotor core (4) circumference extends, empty slot (7) with permanent magnet groove (6) are followed rotor core (4) circumference is arranged alternately, adjacent empty slot (7) and permanent magnet groove (6) each occupy a magnetic pole.

2. The motor rotor according to claim 1, characterized in that the permanent magnet slots (6) are arranged in at least two layers in the radial direction under one pole, the maximum pole arc angle of the empty slots (7) is α1, and the maximum pole arc angle of the outer layer of the permanent magnet slots (6) near the outer circumference side of the rotor core (4) is α2, α1 < α2.

3. The motor rotor of claim 2, wherein 0.8 +.1/α2 +.0.9.

4. The motor rotor according to claim 1, characterized in that the radial thickness of the empty slots (7) is a, the permanent magnet slots (6) are two layers, the radial thickness of the permanent magnet slots (6) located at the radial inner side is B1, and the radial thickness of the permanent magnet slots (6) located at the radial outer side is B2,0.15 +.a/(b1+b2) +.0.35.

5. An electric motor rotor as claimed in claim 1, characterized in that the hollow slot (7) comprises a plurality of segments, in a cross section perpendicular to the central axis of the rotor core (4), the segments being arranged at intervals along the length direction of the hollow slot (7), magnetic bridges (9) being formed between adjacent segments, the number of the magnetic bridges (9) formed between segments of one hollow slot (7) being at least three.

6. A motor rotor according to claim 5, characterized in that the width of the magnetic bridge (9) formed by the segments of the same empty slot (7) increases from the symmetry center line of the empty slot (7) to both sides.

7. The motor rotor according to claim 1, characterized in that the rotor core (4) is divided into a plurality of magnetic pole areas uniformly in the circumferential direction with reference to the symmetry center line of the permanent magnet slots (6), the symmetry center line of each magnetic pole area is the uniform distribution center line of the rotor core (4), and the symmetry center line of the empty slot (7) is deviated from the uniform distribution center line of the magnetic pole where the empty slot (7) is located.

8. The motor rotor according to claim 7, characterized in that the direction of the offset of the symmetry center line of the empty slots (7) with respect to the uniform distribution center line is the rear side of the rotation direction of the rotor core (4).

9. The motor rotor according to claim 7, characterized in that the offset angle of the symmetry center line of the empty slots (7) relative to the uniformly distributed center line is beta, the permanent magnet slots (6) are two layers, and the polar arc included angle between the permanent magnet slots (6) on the same side is beta 1, and beta/beta 1 is more than or equal to 0.9 and less than or equal to 1.1.

10. The electric machine rotor of claim 9, wherein β = β1.

11. A permanent magnet synchronous motor comprising a motor rotor (2) and a motor stator (1), characterized in that the motor rotor (2) is a motor rotor (2) according to any one of claims 1 to 10, the motor rotor (2) is sleeved in the motor stator (1) and forms an air gap with the motor stator (1).