CN116345831A - Bearingless switch reluctance motor with tooth-shaped structure - Google Patents

Abstract

The invention relates to a bearingless switched reluctance motor with a tooth-shaped structure, which comprises: the double salient pole stator and rotor comprises a rotor and a stator sleeved on the periphery of the rotor; the stator is provided with a plurality of groups of stator teeth which extend towards the rotor correspondingly; the rotor is provided with a plurality of groups of rotor teeth extending outwards; a plurality of stator windings are wound on the stator teeth; an auxiliary groove inside the tooth pole of the stator tooth is arranged on the inner side of the stator tooth; the rotor teeth of the rotor are provided with auxiliary grooves inside rotor teeth and poles. The invention provides a bearingless switched reluctance motor with a tooth-shaped structure, which can increase the reluctance and change the distribution of magnetic force lines in the motor, thereby weakening the radial magnetic density in an air gap, increasing the tangential magnetic density, finally achieving the purposes of increasing average torque and greatly reducing torque pulsation and being beneficial to improving the performance of the bearingless switched reluctance motor.

Description

Bearingless switch reluctance motor with tooth-shaped structure

Technical Field

The invention relates to the field of machinery, in particular to a bearingless switch reluctance motor with a tooth-shaped structure.

Background

In the prior art, for example, there are existing patents, patent nos.: CN202110629280.2, patent name: a novel switch reluctance motor with a stator-rotor tooth-shaped structure; the disclosed novel switch reluctance motor with stator and rotor tooth-shaped structure comprises a stator, a rotor, a rotating shaft, stator arc teeth, a rotor auxiliary groove and a rotor ventilation opening. The rotor is embedded in the stator, the rotor is coaxial with the stator, the rotating shaft is arranged at the center of the rotor, the arc-shaped tooth structure of the stator is an inward arc-shaped structure at two sides of the stator tooth, the rotor auxiliary groove is a rectangular groove formed at two sides of the rotor tooth, and the rotor ventilation opening is formed in the rotor.

Due to the special double salient pole structure of the switch reluctance motor and the power supply mode of the switch form, the saturation degree of the salient pole part of the stator and the rotor is high in the running process of the motor, the influence of the fringe magnetic flux effect is obvious, the magnetic circuit is highly saturated, the magnetic circuit characteristic is more complex than that of other motors, the parameters such as current, magnetic flux and the like show the characteristic of nonlinear change, and the torque pulsation is more obvious than that of other motors. Meanwhile, the electromagnetic torque of the switched reluctance motor is synthesized by the torque of adjacent two phases, and the current nonlinear change caused by the power supply mode of a switch form and the high saturation of a magnetic circuit also causes the torque pulsation of the motor during the phase change.

Although the three-phase 12/8 pole bearingless switched reluctance motor is a special switched reluctance motor, the double salient pole structure and the switching power supply mode of the motor are not changed, so that the problem of larger torque pulsation still exists, and the further development of the bearingless switched reluctance motor is hindered.

Disclosure of Invention

The invention overcomes the defects of the prior art, provides the bearingless switch reluctance motor with the tooth-shaped structure, can increase the reluctance and change the distribution of magnetic force lines in the motor, thereby weakening the radial magnetic density in an air gap, increasing the tangential magnetic density, finally achieving the purposes of increasing average torque and greatly reducing torque pulsation, and is beneficial to improving the performance of the bearingless switch reluctance motor.

In order to achieve the above purpose, the invention adopts the following technical scheme: a bearingless switched reluctance motor of tooth construction comprising: the double salient pole stator and rotor comprises a rotor and a stator sleeved on the periphery of the rotor; the stator is provided with a plurality of groups of stator teeth which extend towards the rotor correspondingly; the rotor is provided with a plurality of groups of rotor teeth extending outwards; a plurality of stator windings are wound on the stator teeth; an auxiliary groove inside the tooth pole of the stator tooth is arranged on the inner side of the stator tooth; the rotor teeth of the rotor are provided with auxiliary grooves inside rotor teeth and poles.

In a preferred embodiment of the invention, the auxiliary grooves in the rotor teeth are parallelogram auxiliary grooves.

In a preferred embodiment of the present invention, the auxiliary slots in the stator teeth are square auxiliary slots.

In a preferred embodiment of the present invention, the anticlockwise direction is the rotation direction of the rotor when the motor is running; the stator tooth edge is the tooth edge of the stator tooth in the contact direction of the stator tooth and the rotor tooth when the motor rotor rotates; the side length of the auxiliary groove in the stator tooth pole is 3.03% -15.15% of the stator pole width, the distance from the tooth edge of the stator tooth is 1.51% -15.1% of the stator pole width, and the distance from the tooth top of the stator tooth is 1.21% -6.05% of the stator pole height.

In a preferred embodiment of the present invention, the anticlockwise direction is the rotation direction of the rotor when the motor is running; the rotor tooth edge is the tooth edge of the rotor tooth in the contact direction of the stator tooth and the rotor tooth when the motor rotor rotates; the side length of the auxiliary groove in the rotor tooth pole is 14.3% -28.6% of the extremely high rotor, the height is 7.75% -10.85% of the extremely wide rotor, the distance from the tooth edge of the rotor tooth pole is 1.16% -3.48% of the extremely wide rotor, and the distance from the tooth top of the rotor tooth pole is 1.43% -5.73% of the extremely high rotor.

In a preferred embodiment of the invention, the method is applicable to a three-phase 12/8-pole switched reluctance motor or a three-phase 12/8-pole bearingless switched reluctance motor; the stator adopts 12 sets of stator windings.

In a preferred embodiment of the present invention, the torque ripple factor is: (T1-T2)/t3=0.73; wherein T1 is the maximum torque value of the motor in stable operation, T2 is the minimum torque value of the motor in stable operation, T3 is the average torque value of the motor in stable operation, and the torque ripple coefficient is 0.73.

In a preferred embodiment of the present invention, the auxiliary grooves inside the rotor teeth are arranged on the tooth ends of the rotor teeth on the side where the rotor teeth are preferentially contacted with the stator teeth; the stator tooth pole internal auxiliary groove is arranged on the tooth end of the stator tooth on one side where the stator tooth is preferentially contacted with the rotor tooth.

In a preferred embodiment of the present invention, a method for changing the average torque of a motor, a bearingless switched reluctance motor adopting a tooth structure, comprises the following steps: the average torque of the motor is enhanced by changing the structural forms of the stator and the rotor of the motor, and the torque pulsation of the motor is greatly reduced.

The rotor teeth are internally provided with parallelogram auxiliary grooves, the stator teeth are internally provided with square auxiliary grooves, so that magnetic resistance in a magnetic circuit can be increased, the trend of magnetic lines of force is changed, radial magnetic density in an air gap is further weakened, tangential magnetic density is increased, average torque is increased, and torque pulsation is greatly reduced.

The magnetic flux is always closed along the path with minimum magnetic resistance, and the parallelogram auxiliary grooves are formed in the rotor tooth poles, so that the magnetic resistance in the magnetic circuit can be improved, the trend of magnetic force lines is changed, the magnetic force lines enter the rotor through the magnetic circuit between the parallelogram auxiliary grooves and the rotor tooth tops, the angle of the magnetic flux entering the rotor teeth is changed, the radial magnetic density in an air gap is reduced, the tangential magnetic density is increased, the average torque is improved, and the inherent torque pulsation is reduced.

The square auxiliary grooves are formed in the tooth poles of the stator teeth, so that magnetic resistance in the magnetic circuit is increased, the trend of magnetic force lines is changed, and when the magnetic force lines rotate with a motor rotor through the square auxiliary grooves, the magnetic circuit between the tooth sides of the stator teeth in the contact direction of the stator teeth and the rotor teeth is enabled to be extruded, and part of the magnetic force lines enter the rotor teeth through the non-overlapping area of the stator teeth and the rotor teeth; the radial force generated in the overlapping area of the stator teeth and the rotor teeth is effective radial force, the radial component of the magnetic force lines in the non-overlapping area of the stator teeth and the rotor teeth is ineffective component, and the tangential force is generated at the edges of the two overlapping areas, so that the tangential component of the part is effective component, and finally, the torque pulsation can be further reduced.

The invention solves the defects existing in the background technology, and has the beneficial effects that:

the invention provides a novel tooth-shaped structure, which can improve the average torque and greatly reduce the torque pulsation of a motor, thereby improving the performance of the motor. The parallelogram auxiliary groove is formed in the rotor teeth, so that radial magnetic density in an air gap can be weakened, tangential magnetic density is increased, torque is improved, and torque pulsation of a motor is reduced. The square auxiliary grooves are formed in the stator teeth, so that magnetic resistance can be increased, the trend of magnetic force lines on the stator teeth is changed, the air gap flux density waveform is optimized, torque pulsation of the motor is further reduced, and the performance of the motor is improved.

Drawings

FIG. 1 is a schematic diagram of a novel tooth configuration wide rotor tooth bearingless switched reluctance motor in accordance with a preferred embodiment of the present invention;

FIG. 2 is a schematic diagram of a novel tooth-shaped structure of a wide rotor tooth bearingless switched reluctance motor stator tooth according to a preferred embodiment of the present invention;

FIG. 3 is a schematic diagram of a wide rotor tooth bearingless switched reluctance motor rotor tooth of a novel tooth form structure in accordance with a preferred embodiment of the present invention;

FIG. 4 is a schematic diagram of simulation results of torque comparison between a novel tooth-shaped wide rotor tooth bearingless switched reluctance motor and a conventional wide rotor tooth bearingless switched reluctance motor;

FIG. 5 is a model machine dimension parameter of a novel tooth-shaped wide rotor tooth bearingless switched reluctance motor of the present invention;

FIG. 6 is a graph of radial magnetic density contrast of an original model and a modified model;

FIG. 7 shows that the maximum tangential magnetic flux density of the original model is 0.31T, and the maximum tangential magnetic flux density of the improved model is 0.43T, which is increased by 38.7%;

FIG. 8 is a schematic diagram of the original model magnetic field line trend;

FIG. 9 is a schematic diagram of an improved model magnetic field line trend;

FIG. 10 is a simulation of the original model magnetic field line trend;

FIG. 11 is a simulation of the improved model flux trend;

FIG. 12 is a schematic diagram of the state of the rotor tooth pole inside parallelogram auxiliary groove side length ranging from 1mm to 2mm to the average motor torque;

FIG. 13 is a schematic diagram of the state of the rotor tooth pole inside parallelogram auxiliary groove side length ranging from 1mm to 2mm to motor torque pulsation;

FIG. 14 is a schematic diagram of the average torque of the motor when the value of the height of the parallelogram auxiliary groove in the rotor tooth pole is 1-1.4 mm;

FIG. 15 is a schematic view of the torque ripple of the motor when the value of the parallelogram auxiliary groove height in the rotor tooth pole is 1-1.4 mm;

FIG. 16 is a schematic view of the effect on the average torque of the motor when the distance of the parallelogram-shaped auxiliary grooves inside the rotor teeth from the rotor teeth edges is in the range of 0.15-0.45 mm;

FIG. 17 is a schematic view of the effect on motor torque ripple when the distance of the parallelogram-shaped auxiliary grooves inside the rotor teeth to the rotor teeth edges is in the range of 0.15-0.45 mm;

FIG. 18 is a schematic view of the effect on the average torque of the motor when the distance of the parallelogram-shaped auxiliary grooves inside the rotor teeth from the rotor teeth tips is in the range of 0.1-0.4 mm;

FIG. 19 is a schematic view of the effect on motor torque ripple when the distance of the parallelogram-shaped auxiliary grooves inside the rotor teeth from the rotor teeth tips is in the range of 0.1-0.4 mm;

FIG. 20 is a schematic view of the effect on the average torque of the motor for a side length range of 0.2-1mm for square auxiliary slots inside the stator teeth;

FIG. 21 is a schematic view of the effect on motor torque ripple for a side length range of 0.2-1mm for a square auxiliary slot inside a stator tooth;

FIG. 22 is a schematic view of the state of the effect of the square auxiliary slots inside the stator poles on the average torque of the motor, with a distance from the stator teeth ranging from 0.1 to 1 mm;

FIG. 23 is a schematic view of the effect on motor torque ripple when the distance of the square auxiliary slots inside the stator teeth to the stator teeth edges is in the range of 0.1-1 mm;

FIG. 24 is a schematic view of the effect on the average torque of the motor for a range of 0.2-1mm of the distance of the square auxiliary slots inside the stator teeth from the stator teeth tips;

FIG. 25 is a schematic view of the effect on motor torque ripple when the distance of the square auxiliary slots inside the stator teeth to the stator teeth tips is in the range of 0.2-1 mm;

wherein, 1-stator; 2-rotor; 3-stator windings; 4-stator teeth; 5-rotor teeth; 6-square auxiliary grooves; 7-parallelogram auxiliary grooves; 8-stator tooth edges; 9-rotor tooth edge.

Description of the embodiments

The invention will now be described in further detail with reference to the drawings and examples, which are simplified schematic illustrations of the basic structure of the invention, which are presented only by way of illustration, and thus show only the structures that are relevant to the invention.

Examples

As shown in fig. 1 to 25, a bearingless switched reluctance motor of a tooth structure includes: the doubly salient stator and rotor comprises a rotor 2, and stators 1 and 12 sleeved on the periphery of the rotor 2 are sleeved with stator windings 3. The stator 1 and the rotor 2 are both of salient pole structure. The stator 1 is provided with a plurality of groups of stator teeth 4 which extend towards the rotor 2 correspondingly; the rotor 2 is provided with a plurality of groups of rotor teeth 5 extending outwards; a plurality of stator windings 3 are wound on the stator teeth 4.

The inner side of the stator teeth 4 is provided with stator teeth pole inner auxiliary grooves; the auxiliary grooves in the stator teeth are square auxiliary grooves 6. The anticlockwise direction is taken as the rotation direction of the rotor 2 when the motor operates; the rotor tooth edge 9 is the tooth edge of the rotor tooth 5 in the contact direction of the stator tooth 4 and the rotor tooth 5 when the motor rotor 2 rotates; the side length of the auxiliary groove in the rotor tooth pole is 14.3% -28.6% of the extremely high rotor 2, the height is 7.75% -10.85% of the extremely wide rotor 2, the distance from the tooth edge 9 of the rotor tooth is 1.16% -3.48% of the extremely wide rotor 2, and the distance from the tooth top of the rotor tooth 5 is 1.43% -5.73% of the extremely high rotor 2.

Rotor teeth 5 of rotor 2 are provided with auxiliary grooves inside rotor teeth poles. The auxiliary grooves in the rotor teeth adopt parallelogram auxiliary grooves 7. Specifically, one side of the parallelogram is parallel to the side of the rotor tooth 5, and the other side corresponds to the top arc of the rotor tooth 5. The anticlockwise direction is taken as the rotation direction of the rotor 2 when the motor operates; the stator tooth edge 8 is the tooth edge of the stator tooth 4 in the contact direction of the stator tooth 4 and the rotor tooth 5 when the motor rotor 2 rotates; the side length of the auxiliary groove in the stator tooth pole is 3.03% -15.15% of the pole width of the stator 1, the distance from the tooth edge 8 of the stator tooth is 1.51% -15.1% of the pole width of the stator 1, and the distance from the tooth top of the stator tooth 4 is 1.21% -6.05% of the extremely high stator 1.

Specifically, the torque ripple coefficient is (T1-T2)/t3=0.73; wherein T1 is the maximum torque value of the motor in stable operation, T2 is the minimum torque value of the motor in stable operation, and T3 is the average torque value of the motor in stable operation.

The rotor tooth pole internal auxiliary groove is arranged on the tooth end of the rotor tooth 5 at one side where the rotor tooth 5 is preferentially contacted with the stator tooth 4; the stator tooth pole internal auxiliary groove is provided on the tooth end of the stator tooth 4 on the side where the stator tooth 4 is preferentially contacted with the rotor tooth 5.

Examples

As shown in fig. 1 to 25, a bearingless switched reluctance motor of a tooth structure includes: the doubly salient stator and rotor 2 comprises a rotor 2, and stators 1 and 12 sleeved on the periphery of the rotor 2 are sleeved with stator windings 3. The stator 1 and the rotor 2 are both of salient pole structure. The stator 1 is provided with a plurality of groups of stator teeth 4 which extend towards the rotor 2 correspondingly; the rotor 2 is provided with a plurality of groups of rotor teeth 5 extending outwards; a plurality of stator windings 3 are wound on the stator teeth 4.

The inner side of the stator teeth 4 is provided with stator teeth pole inner auxiliary grooves; the auxiliary grooves in the stator teeth are square auxiliary grooves 6. The anticlockwise direction is taken as the rotation direction of the rotor 2 when the motor operates; the rotor tooth edge 9 is the tooth edge of the rotor tooth 5 in the contact direction of the stator tooth 4 and the rotor tooth 5 when the motor rotor 2 rotates; the side length of the auxiliary groove in the rotor tooth pole is 14.3% -28.6% of the extremely high rotor 2, the height is 7.75% -10.85% of the extremely wide rotor 2, the distance from the tooth edge 9 of the rotor tooth is 1.16% -3.48% of the extremely wide rotor 2, and the distance from the tooth top of the rotor tooth 5 is 1.43% -5.73% of the extremely high rotor 2.

Rotor teeth 5 of rotor 2 are provided with auxiliary grooves inside rotor teeth poles. The auxiliary grooves in the rotor teeth adopt parallelogram auxiliary grooves 7. The anticlockwise direction is taken as the rotation direction of the rotor 2 when the motor operates; the stator tooth edge 8 is the tooth edge of the stator tooth 4 in the contact direction of the stator tooth 4 and the rotor tooth 5 when the motor rotor 2 rotates; the side length of the auxiliary groove in the stator tooth pole is 3.03% -15.15% of the pole width of the stator 1, the distance from the tooth edge 8 of the stator tooth is 1.51% -15.1% of the pole width of the stator 1, and the distance from the tooth top of the stator tooth 4 is 1.21% -6.05% of the extremely high stator 1.

Specifically, the torque ripple coefficient is (T1-T2)/t3=0.73; wherein T1 is the maximum torque value of the motor in stable operation, T2 is the minimum torque value of the motor in stable operation, and T3 is the average torque value of the motor in stable operation. The rotor tooth pole internal auxiliary groove is arranged on the tooth end of the rotor tooth 5 at one side where the rotor tooth 5 is preferentially contacted with the stator tooth 4; the stator tooth pole internal auxiliary groove is provided on the tooth end of the stator tooth 4 on the side where the stator tooth 4 is preferentially contacted with the rotor tooth 5.

Further, referring to fig. 5, structural parameters of the bearingless switched reluctance motor using the wide rotor teeth 5 are designed. Referring to fig. 2, by calculating specific motor structural parameters, the side length of a square auxiliary groove 6 in the inner part of a tooth pole of a stator tooth 4 of the motor is in the range of 0.2mm-1mm, and the side length is taken as 0.7mm in the example; the distance from the tooth edge 8 of the stator is 0.1mm-1mm, and is 0.4mm; the distance from the tooth tip of the stator tooth 4 is in the range of 0.2mm-1mm, taken as 0.4mm. Referring to fig. 3, the calculation is performed by calculating specific motor structural parameters. The length of the parallelogram auxiliary groove 7 in the rotor tooth 5 tooth pole of the motor ranges from 1mm to 2mm, and the length is taken as 2mm in the example; the height range is 1mm-1.4mm, and is 1.2mm; the distance from the rotor tooth edge 9 is 0.15mm-0.45mm, which is 0.15mm; the distance from the tip of the rotor tooth 5 is in the range of 0.1mm to 0.4mm, taken as 0.1mm.

Further, as shown in fig. 6, a radial magnetic density comparison chart of the original model and the improved model is shown; in the graph, the maximum radial magnetic density of the original model is 1.43T, the maximum radial magnetic density of the improved model is 1.2T, and the reduction is 16.1%. FIG. 7 shows that the original model maximum tangential magnetic flux density was 0.31T, and the modified model maximum tangential magnetic flux density was 0.43T, which was an increase of 38.7%.

Fig. 8 is a schematic diagram of the original model magnetic field line trend, and fig. 9 is a schematic diagram of the improved model magnetic field line trend.

It follows that the addition of square auxiliary slots 6 changes the direction of the magnetic field lines inside the poles of the stator teeth 4, so that the tangential component of the magnetic field lines increases and the radial component decreases. Fig. 10 is a simulation diagram of the trend of magnetic lines of force without square auxiliary grooves 6 in the original model; fig. 11 shows a modified magnetic field line trend simulation. In this example, the value range of the side length of the parallelogram auxiliary groove 7 in the rotor tooth 5 pole is 1-2mm, the influence on the average torque and the torque pulsation of the motor is as shown in fig. 12 and 13, when the side length is 2mm, the average torque of the motor is the largest, and the torque pulsation is the smallest, so the side length of the parallelogram auxiliary groove 7 is selected to be 2mm. In this example, the value range of the height of the parallelogram auxiliary groove 7 in the rotor tooth 5 pole is 1-1.4mm, the influence of the value on the average torque and the torque pulsation of the motor is shown in fig. 14 and 15, when the height is 1.2mm, the average torque of the motor is maximum, and the torque pulsation is smaller, so the height of the parallelogram auxiliary groove 7 is 1.2mm. In this example, the distance between the parallelogram auxiliary groove 7 inside the rotor tooth 5 pole and the rotor tooth edge 9 is 0.15-0.45mm, the influence on the average torque and torque pulsation of the motor is shown in fig. 16 and 17, when the distance is 0.15mm, the average torque of the motor is maximum, and the torque pulsation is minimum, so the distance between the parallelogram auxiliary groove 7 and the rotor tooth edge 9 is 0.15mm. In this example, the distance between the parallelogram auxiliary groove 7 inside the rotor tooth 5 pole and the rotor tooth 5 tooth top is 0.1-0.4mm, the influence on the average torque and torque pulsation of the motor is shown in fig. 18 and 19, when the distance is 0.1mm, the average torque of the motor is maximum, and the torque pulsation is minimum, so the distance between the parallelogram auxiliary groove 7 and the rotor tooth 5 tooth top is 0.1mm. In this example, the side length of the square auxiliary groove 6 in the pole of the stator tooth 4 is in the range of 0.2-1mm, the influence on the average torque and the torque pulsation of the motor is as shown in fig. 20 and 21, when the side length is 0.7mm, the average torque of the motor is larger, and the torque pulsation is minimum, so the side length of the square auxiliary groove 6 is selected to be 0.7mm in this scheme. In this example, the distance between the square auxiliary groove 6 inside the stator teeth 4 and the stator tooth edge 8 is 0.1-1mm, the influence on the average torque and torque pulsation of the motor is shown in fig. 22 and 23, when the distance is 0.4mm, the average torque of the motor is larger, and the torque pulsation is minimum, so the distance between the square auxiliary groove 6 and the stator tooth edge 8 is 0.4mm. In this example, the distance between the square auxiliary groove 6 inside the stator teeth 4 and the tooth tops of the stator teeth 4 is 0.2-1mm, the influence on the average torque and torque pulsation of the motor is shown in fig. 24 and 25, when the distance is 0.4mm, the average torque of the motor is larger, and the torque pulsation is minimum, so that the distance between the square auxiliary groove 6 and the tooth tops of the stator teeth 4 is 0.4mm.

Examples

On the basis of the first or second embodiment; the motor is suitable for a three-phase 12/8-pole switched reluctance motor or a three-phase 12/8-pole bearingless switched reluctance motor; the stator 1 adopts 12 sets of stator windings 3.

Specifically, as shown in fig. 1 to 3, a bearingless switched reluctance motor of a tooth structure includes: the doubly salient stator and rotor 2 comprises a rotor 2, and stators 1 and 12 sleeved on the periphery of the rotor 2 are sleeved with stator windings 3. The stator 1 and the rotor 2 are both of salient pole structure. The stator 1 is provided with a plurality of groups of stator teeth 4 which extend towards the rotor 2 correspondingly; the rotor 2 is provided with a plurality of groups of rotor teeth 5 extending outwards; a plurality of stator windings 3 are wound on the stator teeth 4.

The inner side of the stator teeth 4 is provided with stator teeth pole inner auxiliary grooves; the auxiliary grooves in the stator teeth are square auxiliary grooves 6. The anticlockwise direction is taken as the rotation direction of the rotor 2 when the motor operates; the rotor tooth edge 9 is the tooth edge of the rotor tooth 5 in the contact direction of the stator tooth 4 and the rotor tooth 5 when the motor rotor 2 rotates; the side length of the auxiliary groove in the rotor tooth pole is 14.3% -28.6% of the extremely high rotor 2, the height is 7.75% -10.85% of the extremely wide rotor 2, the distance from the tooth edge 9 of the rotor tooth is 1.16% -3.48% of the extremely wide rotor 2, and the distance from the tooth top of the rotor tooth 5 is 1.43% -5.73% of the extremely high rotor 2.

Rotor teeth 5 of rotor 2 are provided with auxiliary grooves inside rotor teeth poles. The auxiliary grooves in the rotor teeth adopt parallelogram auxiliary grooves 7. The anticlockwise direction is taken as the rotation direction of the rotor 2 when the motor operates; the stator tooth edge 8 is the tooth edge of the stator tooth 4 in the contact direction of the stator tooth 4 and the rotor tooth 5 when the motor rotor 2 rotates; the side length of the auxiliary groove in the stator tooth pole is 3.03% -15.15% of the pole width of the stator 1, the distance from the tooth edge 8 of the stator tooth is 1.51% -15.1% of the pole width of the stator 1, and the distance from the tooth top of the stator tooth 4 is 1.21% -6.05% of the extremely high stator 1.

Specifically, the torque ripple coefficient is (T1-T2)/t3=0.73; wherein T1 is the maximum torque value of the motor in stable operation, T2 is the minimum torque value of the motor in stable operation, and T3 is the average torque value of the motor in stable operation.

The rotor tooth pole internal auxiliary groove is arranged on the tooth end of the rotor tooth 5 at one side where the rotor tooth 5 is preferentially contacted with the stator tooth 4; the stator tooth pole internal auxiliary groove is provided on the tooth end of the stator tooth 4 on the side where the stator tooth 4 is preferentially contacted with the rotor tooth 5.

Examples

On the basis of the first or second embodiment; the motor is suitable for a three-phase 12/8-pole switched reluctance motor or a three-phase 12/8-pole bearingless switched reluctance motor; the stator 1 adopts 12 sets of stator windings 3.

Specifically, as shown in fig. 1 to 3, a bearingless switched reluctance motor of a tooth structure includes: the doubly salient stator and rotor 2 comprises a rotor 2, and stators 1 and 12 sleeved on the periphery of the rotor 2 are sleeved with stator windings 3. The stator 1 and the rotor 2 are both of salient pole structure. The stator 1 is provided with a plurality of groups of stator teeth 4 which extend towards the rotor 2 correspondingly; the rotor 2 is provided with a plurality of groups of rotor teeth 5 extending outwards; a plurality of stator windings 3 are wound on the stator teeth 4.

The inner side of the stator teeth 4 is provided with stator teeth pole inner auxiliary grooves; the auxiliary grooves in the stator teeth are square auxiliary grooves 6. The anticlockwise direction is taken as the rotation direction of the rotor 2 when the motor operates; the rotor tooth edge 9 is the tooth edge of the rotor tooth 5 in the contact direction of the stator tooth 4 and the rotor tooth 5 when the motor rotor 2 rotates; the side length of the auxiliary groove in the rotor tooth pole is 14.3% -28.6% of the extremely high rotor 2, the height is 7.75% -10.85% of the extremely wide rotor 2, the distance from the tooth edge 9 of the rotor tooth is 1.16% -3.48% of the extremely wide rotor 2, and the distance from the tooth top of the rotor tooth 5 is 1.43% -5.73% of the extremely high rotor 2.

Rotor teeth 5 of rotor 2 are provided with auxiliary grooves inside rotor teeth poles. The auxiliary grooves in the rotor teeth adopt parallelogram auxiliary grooves 7. The anticlockwise direction is taken as the rotation direction of the rotor 2 when the motor operates; the stator tooth edge 8 is the tooth edge of the stator tooth 4 in the contact direction of the stator tooth 4 and the rotor tooth 5 when the motor rotor 2 rotates; the side length of the auxiliary groove in the stator tooth pole is 3.03% -15.15% of the pole width of the stator 1, the distance from the tooth edge 8 of the stator tooth is 1.51% -15.1% of the pole width of the stator 1, and the distance from the tooth top of the stator tooth 4 is 1.21% -6.05% of the extremely high stator 1.

Specifically, the torque ripple coefficient is (T1-T2)/t3=0.73; wherein T1 is the maximum torque value of the motor in stable operation, T2 is the minimum torque value of the motor in stable operation, and T3 is the average torque value of the motor in stable operation.

The rotor tooth pole internal auxiliary groove is arranged on the tooth end of the rotor tooth 5 at one side where the rotor tooth 5 is preferentially contacted with the stator tooth 4; the stator tooth pole internal auxiliary groove is provided on the tooth end of the stator tooth 4 on the side where the stator tooth 4 is preferentially contacted with the rotor tooth 5.

Examples

On the basis of the first embodiment, the second embodiment, the third embodiment or the fourth embodiment; a method for changing the average torque of a motor, which adopts a bearingless switched reluctance motor with a tooth-shaped structure, comprising the following steps: the average torque of the motor is enhanced by changing the structural forms of the stator 1 and the rotor 2 of the motor, and the torque pulsation of the motor is greatly reduced.

The rotor teeth 5 are internally provided with parallelogram auxiliary grooves 7, the stator teeth 4 are internally provided with square auxiliary grooves 6, so that magnetic resistance in a magnetic circuit can be increased, the trend of magnetic lines of force can be changed, radial magnetic density in an air gap can be further weakened, tangential magnetic density can be increased, average torque can be increased, and torque pulsation can be greatly reduced.

The magnetic flux is always closed along the path with minimum magnetic resistance, and the parallelogram auxiliary groove 7 is formed in the tooth pole of the rotor tooth 5, so that the magnetic resistance in the magnetic circuit can be improved, the trend of magnetic force lines is changed, the magnetic force lines enter the rotor 2 through the magnetic circuit between the parallelogram auxiliary groove 7 and the tooth top of the rotor tooth 5, the angle of the magnetic flux entering the rotor tooth 5 is changed, the radial magnetic density in an air gap is reduced, the tangential magnetic density is increased, the average torque is improved, and the inherent torque pulsation is reduced.

Square auxiliary grooves 6 are formed in the tooth poles of the stator teeth 4, magnetic resistance in a magnetic circuit is increased, the trend of magnetic force lines is changed, and when the magnetic force lines rotate with the motor rotor 2 through the square auxiliary grooves 6, the magnetic circuit between the tooth edges 8 of the stator teeth 5 in the contact direction of the stator teeth 5 is formed, so that part of the magnetic force lines are extruded, and enter the rotor teeth 5 through a non-overlapping area of the stator teeth 5; the radial force generated in the overlapping area of the stator and rotor teeth 5 is effective radial force, the radial component of the magnetic force lines in the non-overlapping area of the stator and rotor teeth 5 is ineffective component, and the tangential force is generated at the edges of the two overlapping areas, so that the tangential component of the part is effective component, and finally, the torque pulsation can be further reduced.

Working principle:

as shown in fig. 1-25, the bearingless switched reluctance motor with the tooth-shaped structure in the invention takes a 12/8-pole wide rotor tooth 5 bearingless switched reluctance motor as an example, and the average torque of the motor is enhanced by changing the structural forms of a motor stator 1 and a motor rotor 2, so that the torque pulsation of the motor is greatly reduced, and the performance of the motor is improved. The structure and the working principle of the wide rotor tooth 5 bearingless switched reluctance motor are simpler, the mechanical angle of the rotor tooth 5 is increased from 15 degrees of the traditional bearingless switched reluctance motor to 30 degrees, and the change solves the coupling problem of the traditional BSRM torque and the levitation force. The doubly salient structure of the motor and the switching power supply are not altered, however, resulting in the inherent torque ripple still being present. The existence of torque pulsation can influence the stable operation of the motor, aggravate the vibration of the motor, thereby quickening the abrasion of components such as a motor rotating shaft and reducing the service life of the abraded components, and influencing the popularization and the use of the bearingless switch reluctance motor. The rotor teeth 5 are internally provided with the parallelogram auxiliary grooves 7, and the stator teeth 4 are internally provided with the square auxiliary grooves 6, so that the magnetic resistance in a magnetic circuit can be increased, the trend of magnetic lines of force can be changed, the radial magnetic density in an air gap can be further weakened, the tangential magnetic density can be increased, and the purposes of increasing average torque and greatly reducing torque pulsation can be achieved.

More specifically, based on the principle of minimum reluctance of the BSRMWR, that is, the magnetic flux is always closed along the path of minimum reluctance, the parallelogram auxiliary grooves 7 are formed in the tooth poles of the rotor teeth 5, so that the reluctance in the magnetic circuit can be improved, the trend of magnetic force lines is changed, the magnetic force lines enter the rotor 2 through the magnetic circuit between the parallelogram auxiliary grooves 7 and the tooth tops of the rotor teeth 5, the angle of the magnetic flux entering the rotor teeth 5 is changed, the radial magnetic density in an air gap is reduced, the tangential magnetic density is increased, the average torque of the BSRMWR is improved, and the inherent torque pulsation is reduced.

The square auxiliary grooves 6 are formed in the tooth poles of the stator teeth 4, magnetic resistance in a magnetic circuit is increased, the trend of magnetic force lines is changed, and when the magnetic force lines rotate with the motor rotor 2 through the square auxiliary grooves 6, the magnetic circuit between the tooth edges 8 of the stator teeth 5 in the contact direction of the stator teeth 5 is formed, so that part of the magnetic force lines are extruded, and enter the rotor teeth 5 through a non-overlapping area of the stator teeth 5. Because only the radial force generated in the overlapping area of the stator and rotor teeth 5 is effective radial force, the radial component of the magnetic force lines in the non-overlapping area of the stator and rotor teeth 5 is ineffective component, and the tangential force is generated at the edges of the two overlapping areas, the tangential component of the part is effective component, and finally the aim of further reducing the torque pulsation can be achieved.

The same current is respectively transmitted to the BSRMWR adopting the novel tooth-shaped structure and the traditional BSRMWR by current chopping control to carry out simulation test. The prior art improvements, although reducing torque ripple, do not compromise the average torque of the motor and may even reduce the average torque. The scheme can improve the minimum value of the synthesized torque, greatly reduce the torque pulsation of the motor and improve the average torque of the motor. Fig. 4 is a graph of output torque versus steady state operation of BSRMWR employing the novel tooth configuration of the present invention and conventional BSRMWR. In the steady state operation process of the motor, the BSRMWR output average torque of the novel tooth-shaped structure is 0.802N.m, the traditional BSRMWR output average torque is 0.762N.m, and the average torque is improved by 5.25%. According to a torque ripple coefficient calculation formula: (maximum torque value at the time of motor steady operation-minimum torque value at the time of motor steady operation)/average torque value at the time of motor steady operation, it is possible to obtain: the torque ripple coefficient of BSRMWR adopting the novel tooth-shaped structure is 0.73, the torque ripple coefficient of the traditional BSRMWR is 1.22, and the torque ripple coefficient is reduced by 40.2%. According to the calculation result, the BSRMWR of the novel tooth-shaped structure can achieve the purposes of increasing the average torque and greatly reducing the torque pulsation.

The above-described preferred embodiments according to the present invention are intended to suggest that, from the above description, various changes and modifications can be made by the person skilled in the art without departing from the scope of the technical idea of the present invention. The technical scope of the present invention is not limited to the description, but must be determined according to the scope of claims.

Claims (10)

1. The bearingless switch reluctance motor with the tooth-shaped structure is characterized by comprising a doubly salient stator and a doubly salient rotor, wherein the doubly salient stator and the doubly salient rotor comprise a rotor and a stator sleeved on the periphery of the rotor;

a plurality of groups of stator teeth which extend towards the rotor correspondingly are arranged on the stator;

the rotor is provided with a plurality of groups of rotor teeth extending outwards;

a plurality of stator windings are wound on the stator teeth;

the inner side of the stator teeth is provided with an auxiliary groove inside the stator teeth pole

The rotor teeth of the rotor are provided with auxiliary grooves inside rotor teeth poles.

2. The bearingless switched reluctance motor of tooth structure of claim 1 wherein: the auxiliary grooves in the rotor tooth poles adopt parallelogram auxiliary grooves.

3. The bearingless switched reluctance motor of tooth structure of claim 2 wherein: the auxiliary grooves in the stator teeth are square auxiliary grooves.

4. A bearingless switched reluctance motor of tooth construction according to claim 3, wherein: the anticlockwise direction is taken as the rotation direction of the rotor when the motor operates;

the stator tooth edge is the tooth edge of the stator tooth in the contact direction of the stator tooth and the rotor tooth when the motor rotor rotates;

the side length of the auxiliary groove in the stator tooth pole is 3.03% -15.15% of the stator pole width, the distance from the tooth edge of the stator tooth is 1.51% -15.1% of the stator pole width, and the distance from the tooth top of the stator tooth is 1.21% -6.05% of the stator pole height.

5. The tooth construction bearingless switched reluctance motor of claim 4 wherein: the anticlockwise direction is taken as the rotation direction of the rotor when the motor operates;

the rotor tooth edge is the tooth edge of the rotor tooth in the contact direction of the stator tooth and the rotor tooth when the motor rotor rotates;

the side length of the auxiliary groove in the rotor tooth pole is 14.3% -28.6% of the extremely high rotor, the height is 7.75% -10.85% of the extremely wide rotor, the distance from the tooth edge of the rotor tooth pole is 1.16% -3.48% of the extremely wide rotor, and the distance from the tooth top of the rotor tooth pole is 1.43% -5.73% of the extremely high rotor.

6. The tooth construction bearingless switched reluctance motor of claim 5 wherein: the motor is suitable for a three-phase 12/8-pole switched reluctance motor or a three-phase 12/8-pole bearingless switched reluctance motor; the stator adopts 12 sets of stator windings.

7. The tooth construction bearingless switched reluctance motor of claim 5 wherein: the torque ripple coefficient is: (T1-T2)/t3=0.73; wherein T1 is the maximum torque value of the motor in stable operation, T2 is the minimum torque value of the motor in stable operation, and T3 is the average torque value of the motor in stable operation.

8. A bearingless switched reluctance motor of tooth construction according to claim 3, wherein: the rotor tooth pole internal auxiliary groove is arranged on the tooth end of the rotor tooth on one side where the rotor tooth is preferentially contacted with the stator tooth;

the stator tooth pole internal auxiliary groove is arranged on the tooth end of the stator tooth on one side where the stator tooth is preferentially contacted with the rotor tooth.

9. A method of varying the average torque of an electric motor, characterized in that a bearingless switched reluctance motor of the toothed structure of any one of claims 1-8 is employed; the method comprises the following steps:

the average torque of the motor is enhanced by changing the structural forms of the stator and the rotor of the motor, and the torque pulsation of the motor is greatly reduced.

10. The method of varying average motor torque according to claim 9, wherein:

the rotor teeth are internally provided with parallelogram auxiliary grooves, the stator teeth are internally provided with square auxiliary grooves, so that magnetic resistance in a magnetic circuit can be increased, the trend of magnetic lines of force can be changed, radial magnetic density in an air gap can be further weakened, tangential magnetic density can be increased, average torque can be increased, and torque pulsation can be greatly reduced;

the magnetic flux is always closed along the path with minimum magnetic resistance, and the parallelogram auxiliary grooves are formed in the rotor tooth poles, so that the magnetic resistance in the magnetic circuit can be improved, the trend of magnetic force lines is changed, the magnetic force lines enter the rotor through the magnetic circuit between the parallelogram auxiliary grooves and the rotor tooth tops, the angle of the magnetic flux entering the rotor teeth is changed, the radial magnetic density in an air gap is reduced, the tangential magnetic density is increased, the average torque is improved, and the inherent torque pulsation is reduced;

the square auxiliary grooves are formed in the tooth poles of the stator teeth, so that magnetic resistance in the magnetic circuit is increased, the trend of magnetic force lines is changed, and when the magnetic force lines rotate with a motor rotor through the square auxiliary grooves, the magnetic circuit between the tooth sides of the stator teeth in the contact direction of the stator teeth and the rotor teeth is enabled to be extruded, and part of the magnetic force lines enter the rotor teeth through the non-overlapping area of the stator teeth and the rotor teeth; the radial force generated in the overlapping area of the stator teeth and the rotor teeth is effective radial force, the radial component of the magnetic force lines in the non-overlapping area of the stator teeth and the rotor teeth is ineffective component, and the tangential force is generated at the edges of the two overlapping areas, so that the tangential component of the part is effective component, and finally, the torque pulsation can be further reduced.

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