KR101209631B1 - Rotor having different length and LSPM(Line-Start Permanent Magnet) motor comprising the rotor - Google Patents

Abstract

The present invention relates to a rotor having a conductor bar of different lengths and a line-start permanent magnet (LSPM) motor including the same, and to solve the imbalance of the pore flux density due to the attractive force generated in the rotational direction of the rotor, The purpose of this invention is to realize the pore flux density in a sinusoidal shape by adjusting the length of the conductor bar at the center and the edge. According to the present invention, the rotor is a rotor of the LSPM motor that is inserted into the rotor insertion hole of the stator to be rotatable, and includes a rotor iron core and a plurality of permanent magnets. The rotor core has a rotation shaft insertion hole in which a rotation shaft is inserted in the center portion, a plurality of permanent magnet insertion holes are formed around the rotation shaft insertion hole, and a plurality of conductors around the outer side of the plurality of permanent magnet insertion holes. A bar insertion hole is formed. The plurality of permanent magnets are respectively inserted into the plurality of permanent magnet insertion holes to form the N pole and the S pole. The plurality of conductor bars are inserted into and installed in the plurality of conductor bar insertion holes, respectively. In this case, the plurality of permanent magnets are relatively smaller in size than the permanent magnets in the size of the permanent magnets in the direction of rotation of the rotary shaft. In addition, the length of the conductor bar of the center portion of the magnetic pole formed by the plurality of permanent magnets is shorter than the length of the conductor bar of the edge portion of the magnetic pole.

Description

Rotor having different length and Line-Start Permanent Magnet (LSPM) motor comprising the rotor}

The present invention relates to a synchronous motor, and more particularly, in a rotor of a synchronous motor having a constant rotational direction, a permanent magnet having a different size is inserted into a rotor core to solve an imbalance in air gap magnetic flux density, The present invention relates to a rotor having a conductor bar having a different length with low vibration and noise by adjusting the length of the conductor bar of the center portion and the edge portion to realize a sine wave shape, and to a LSPM motor including the same. .

In general, a motor (or motor) is a device that generates rotational force by converting electrical energy into mechanical energy, and is widely used in homes and industries. Such motors can be broadly classified into an AC motor and a DC motor.

The DC motor is driven by a DC power source and changes the input voltage to obtain a desired output. The DC motor is relatively easy to control speed and is used for driving a train or an elevator. DC motors can be classified into brush DC motors and brushless DC motors. The brushless DC motor has a feature that there is no mechanical contact between the brush and the commutator, compared to the brush DC motor, thereby achieving high performance, light weight, short life, and long life of the device. In addition, the brushless DC motor has a structure in which a coil is wound around the stator and a permanent magnet is embedded in the rotor. Such brushless DC motors are widely used in various devices according to the development of semiconductor technology and components and materials.

AC motors are driven by AC power and are one of the most widely used motors around life. AC motor basically consists of external stator and internal rotor. When AC current is supplied to stator winding, electric field is converted by electromagnetic induction and guided by electric field rotating in rotor. It is a motor that generates current and generates rotational force on the rotating shaft of the rotor by the torque.

These AC motors are largely divided into single phase and three phase, and may be further classified into induction motors, synchronous motors, and commutator motors depending on the type of rotor.

Synchronous motors, such as LSPM motors (also called 'single-phase induction synchronous motors'), are an AC motor that applies only the advantages of single phase induction motors and synchronous motors. Such a synchronous motor starts rotation of the rotor by the torque generated by the interaction of the secondary current generated by the voltage induced in the conductor bar of the rotor and the magnetic flux generated by the winding of the stator. In rated operation, the magnetic flux of the permanent magnet installed in the rotor and the magnetic flux generated from the stator are synchronized with each other to operate at the speed of the stator's rotor field. That is, when a current is applied to the coil of the stator, the rotor rotates by the interaction between the rotating magnetic flux generated by the stator structure and the induced current generated in the conductor bar of the rotor. When the rotor reaches the synchronous speed, a torque generated by the permanent magnet and a reluctance torque due to the structure of the rotor are generated to rotate the rotor.

The rotor of the LSPM motor has a cylindrical rotor iron core, a plurality of conductor bars are inserted around the edge of the rotor iron core, and a plurality of permanent magnets are inserted inside the conductor bars.

LSPM motors having such a structure have high output power due to the application of high-performance permanent magnets, but have a problem in that vibration and noise due to cogging torque are increased. Cogging torque has a close relationship with the pore flux density between the rotor and the stator. In the conventional LSPM motor, since the pore flux density has a square wave shape, vibration and noise are severely generated.

That is, when the N pole and the S pole are composed of a plurality of permanent magnets installed on the iron core, permanent magnets of the same size with respect to the rotation axis of the rotor are inserted and installed at symmetrical positions. Because of this, when combined with the magnetic force by the winding of the plurality of permanent magnets and stator, the attraction force and repulsive force is generated in the N pole and S pole, respectively, to generate the rotational force continuously.

However, since the attraction force is additionally generated in the direction of rotation of the rotor, the additional attraction force is added at the N pole to increase the pore magnetic flux density. On the contrary, the strength of the magnetic flux is canceled by the additional attraction force at the S pole. As a result, the pore magnetic flux density decreases, so that the pore magnetic flux density of the rotor becomes unbalanced, causing problems such as output reduction and torque ripple increase.

Accordingly, an object of the present invention is to provide a rotor having a conductor bar having a different length having excellent vibration and noise characteristics by reducing cogging torque and an LSPM motor including the same.

Another object of the present invention includes a rotor having a conductor bar having a different length to solve the imbalance of the pore flux density due to the attraction force generated in the rotational direction of the rotor to improve the output of the LSPM motor and to improve the torque ripple, and the same. To provide an LSPM motor.

Still another object of the present invention is to provide a rotor having an conductor bar having a different length of a conductor bar and a LSPM motor including the same by realizing a pore flux density between the rotor and the stator to a sinusoidal shape.

In order to achieve the above object, the present invention is a rotor of the LSPM motor that is inserted into the rotor insertion hole of the stator to be rotatably installed, the LSPM motor comprising a rotor core, a plurality of permanent magnets, and a plurality of conductor bars Provide the rotor. The rotor iron core has a rotation shaft insertion hole in which a rotation shaft is inserted in a central portion thereof, and a plurality of permanent magnet insertion holes are formed around the rotation shaft insertion hole, and around the outer side of the plurality of permanent magnet insertion holes. A plurality of conductor bar insertion holes are formed. The plurality of permanent magnets are respectively inserted into the plurality of permanent magnet insertion holes to form the N pole and the S pole. The plurality of conductor bars are respectively inserted into and inserted into the plurality of conductor bar insertion holes. In this case, the plurality of permanent magnets are relatively smaller in size than the permanent magnets in the front of the permanent magnets in the direction of rotation of the rotary shaft. In addition, the spacing between the conductor bars of the central portion of the magnetic pole formed by the plurality of permanent magnets is formed wider than the interval between the conductor bars of the edge portion of the magnetic pole.

In the rotor of the LSPM motor according to the present invention, the plurality of permanent magnets are installed symmetrically with respect to the rotation shaft insertion hole, and the permanent magnets disposed to face each other are substantially the same in size, and adjacent permanent The magnets may differ in size from each other.

In the rotor of the LSPM motor according to the present invention, the plurality of permanent magnets may be relatively short in length compared to the length of the permanent magnets in the front of the permanent magnets in the direction of rotation of the rotary shaft.

In the rotor of the LSPM motor according to the present invention, the plurality of permanent magnets, the plurality of first permanent magnets forming the N pole and neighboring each other, and the plurality of second permanent magnets forming the S pole and neighboring each other It may include a magnet. In this case, the plurality of first permanent magnets and the second permanent magnets are relatively smaller in size than the permanent magnets in the front of the permanent magnets in the direction of rotation of the rotary shaft, respectively.

In the rotor of the LSPM motor according to the present invention, each of the plurality of first and second permanent magnets is two, an angle between the pair of first permanent magnets, and an angle between the pair of second permanent magnets. Are each 90 degrees or more, and an angle between the neighboring first permanent magnets and the second permanent magnets may be 90 degrees or less.

In the rotor of the LSPM motor according to the present invention, the spacing between the plurality of conductor bars may be provided narrower toward the edge from the center of the magnetic pole.

In the rotor of the LSPM motor according to the present invention, the spacing between the conductor bar insertion holes in the center portion of the magnetic pole formed by the plurality of permanent magnets may be wider than the spacing between the conductor bar insertion holes in the edge portion of the magnetic pole. Can be.

The present invention also provides an LSPM motor including the above-described rotor and a stator in which a rotor insertion hole into which the rotor is inserted in a central portion is formed and a coil is wound around an inner circumferential surface of the rotor insertion hole. .

According to the present invention, by placing a permanent magnet relatively smaller than the size of the permanent magnet in the LSPM motor having a constant rotation direction compared to the size of the permanent magnet in the rotation direction, the air gap due to the attraction force generated in the rotation direction of the rotor By eliminating the imbalance of magnetic flux density, the output of LSPM motor can be improved, torque ripple can be improved, and the cogging torque can be reduced to improve vibration and noise characteristics.

That is, since the attraction force occurs in the rotational direction of the rotor, the strength of the magnetic flux increases due to the attraction force additionally generated by the rotation of the rotor in the former permanent magnet, so the size is reduced, and in the latter permanent magnet in which the repulsion occurs Since the intensity of the magnetic flux decreases due to the additional attraction caused by the rotation of the electrons, the size of the magnetic flux is reduced to compensate for the decrease in the magnetic flux. Can reduce the cogging torque and improve the vibration and noise characteristics.

In addition, the length of the conductor bar of the center of the magnetic pole formed by the plurality of permanent magnets is shorter than the length of the conductor bar of the edge of the magnetic pole. Can be. By implementing the air gap magnetic flux density in the sine wave shape, it is possible to reduce the cogging torque generated when the LSPM motor is driven, thereby reducing the generation of vibration and noise when the LSPM motor is driven.

In addition, the gap between the conductor bars of the center portion of the magnetic pole formed by the plurality of permanent magnets is made wider than the distance between the conductor bars of the edge portion of the magnetic pole. You can implement it closer.

1 is a plan view showing a rotor of an LSPM motor according to a first embodiment of the present invention.
FIG. 2 is a plan view illustrating an LSPM motor having the rotor of FIG. 1. FIG.
FIG. 3 is a view schematically showing a pore magnetic flux density and a waveform diagram according to the rotor structure of FIG. 1.
4 is a plan view illustrating a rotor of an LSPM motor according to a second exemplary embodiment of the present invention.

In the following description, only parts necessary for understanding the operation according to the embodiment of the present invention will be described, it should be noted that the description of other parts will be omitted so as not to distract from the gist of the present invention.

Also, the terms and words used in the present specification and claims should not be construed to be limited to ordinary or dictionary meanings, and the inventor is not limited to the concept of terms in order to describe his invention in the best way. It should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be properly defined. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely one preferred embodiment of the present invention, and not all of the technical ideas of the present invention are described. Therefore, It is to be understood that equivalents and modifications are possible.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a plan view showing a rotor 20 of an LSPM motor according to a first embodiment of the present invention. FIG. 2 is a plan view showing the LSPM motor 100 having the rotor 20 of FIG. 1. 3 is a view schematically showing a pore magnetic flux density generated according to the structure of the rotor 20 of FIG. 1 and a waveform diagram according thereto.

1 to 3, the LSPM motor 100 according to the first embodiment of the present invention includes a rotor 20 and a stator 10 to which the rotor 20 is rotatably inserted. . In the stator 10, a rotor insertion hole 18 is formed in a central portion thereof, and a coil 16 is wound around an inner circumferential surface of the rotor insertion hole 18. The rotor 20 is inserted into the rotor insertion hole 18 of the stator 10 and is rotatably installed.

The stator 10 includes a stator iron core 11 having a rotor insertion hole 18 and a coil 16 wound along an inner circumferential surface of the rotor insertion hole 18 of the stator iron core 11. At this time, the inner diameter of the rotor insertion hole 18 is formed larger than the outer diameter of the rotor 20, the difference between the inner diameter of the rotor insertion hole 18 and the outer diameter of the rotor 20 forms a void.

The stator core 11 is formed by laminating a plurality of stator iron plates 12 of the same shape in the axial direction. The stator iron core 11 has a rotor insertion hole 18 in which a rotor 20 can be inserted and positioned. The stator iron core 11 is formed with a plurality of teeth 14 at regular intervals along the inner circumferential surface. The plurality of teeth 14 protrude from the inner circumferential surface of the stator iron core 11 toward the central axis of the stator iron core 11 and are disposed close to the outer circumferential surface of the rotor 20 inserted and installed in the rotor insertion hole 18. do. At this time, a silicon iron plate may be used as the stator plate 12. The inside of the virtual surface formed by the end of the tooth 14 inside the stator iron core 11 forms the rotor insertion hole 18.

In addition, the coil 16 is wound around the plurality of teeth 14, and when AC power is applied, the coil 16 generates a rotating magnetic flux due to the structure of the stator 10.

On the other hand, although not shown, the rotating shaft 30 is rotatably installed in the casing (shell) or shell (shell) forming the case of the LSPM motor 100 via a bearing.

The rotor 20 is a rotor of an LSPM motor inserted into the rotor insertion hole of the stator and rotatably installed, and includes a rotor iron core 21 and a plurality of permanent magnets 22 embedded in the rotor iron core 21. ), And a plurality of conductor bars 23. The rotor core 21 has a rotating shaft insertion hole 25 in which the rotating shaft 30 is inserted in the center portion, and a plurality of permanent magnet insertion holes 26 are formed around the rotating shaft insertion hole 25. A plurality of conductor bar insertion holes 27 are formed around the outer side of the plurality of permanent magnet insertion holes 25. The plurality of permanent magnets 22 are respectively inserted into the plurality of permanent magnet insertion holes 26 to form the N pole and the S pole. The plurality of conductor bars 23 are inserted into and installed in the plurality of conductor bar insertion holes 27, respectively. In this case, the plurality of permanent magnets 22 are relatively smaller in size than the permanent magnets 22b and 22d, which are larger in size than the permanent magnets 22a and 22c in the rotational direction of the rotation shaft 30. The distance d1 between the conductor bars 23 of the central portion of the magnetic pole formed by the plurality of permanent magnets 22 is wider than the distance d2 between the conductor bars 22 of the edge portion of the magnetic pole. Herein, the rotation direction of the rotation shaft 30 is clockwise with respect to the X axis, and the X axis is a point at which the transformation of the magnetic pole occurs.

As described above, since the size of the permanent magnets 22a and 22c in the rotating direction of the rotary shaft 30 is smaller than the size of the permanent magnets 22b and 22d in the rotor 20 according to the first embodiment, It is possible to improve the output of the LSPM motor 100 and improve torque ripple by reducing the unbalanced magnetic flux density caused by the attraction force generated in the rotational direction of the rotary shaft 30, and to improve the vibration and noise characteristics by reducing the cogging torque. Can be.

In addition, the length L1 of the conductor bar 23 in the center portion of the magnetic pole formed by the permanent magnet 22 is shorter than the length L2 of the conductor bar 23 in the edge portion of the magnetic pole, thereby stimulating the void magnetic flux density. By focusing to the central part of, the pore magnetic flux density can be realized in a sinusoidal shape. By implementing the air gap magnetic flux density in a sinusoidal shape, it is possible to reduce the cogging torque generated when the LSPM motor 100 is driven, thereby reducing the generation of vibration and noise when the LSPM motor 100 is driven.

Referring to the rotor 20 according to the first embodiment in detail as follows.

The rotor core 21 is formed by laminating a plurality of rotor iron plates 24 having the same shape in the axial direction. The rotor core 21 has a rotation shaft insertion hole 25 in which the rotation shaft 30 is inserted in the center portion. The rotor core 21 has a plurality of permanent magnet insertion holes 26 formed outside the rotation shaft insertion hole 25. The rotor iron core 21 has a plurality of conductor bar insertion holes 27 formed around the outer edges of the plurality of permanent magnet insertion holes 26.

At this time, a silicon steel sheet may be used as the rotor iron plate 24. The rotation shaft insertion hole 25 and the permanent magnet insertion hole 26 may be formed in a direction perpendicular to the upper surface of the rotor iron core 21.

Although the four permanent magnet insertion holes 26 in which the permanent magnets 22 are installed in the square at the center of the rotary shaft insertion hole 25 are formed in the rotor iron core 21, an example is not limited thereto.

The plurality of permanent magnets 22 are inserted into and installed in the plurality of permanent magnet insertion holes 26 of the rotor iron core 21, respectively. At this time, the plurality of permanent magnets 22 generate torque by interaction with the magnetic flux generated in the coil 16. As the permanent magnet 22, a rare earth magnet may be used.

In particular, the plurality of permanent magnets 22 are smaller than the size of the permanent magnets 22b and 22d, which are larger in size than the permanent magnets 22a and 22c in the direction of rotation of the rotation shaft 30, in order to solve the imbalance of the void magnetic flux density. It is formed relatively small. That is, since the attraction force occurs in the rotational direction of the rotary shaft 30, in the permanent magnets 22a and 22c, the magnitude of the magnetic flux increases due to the attraction force additionally generated by the rotation of the rotor 20, thereby reducing the size. In the back permanent magnets 22b and 22d where repulsion occurs, the strength of the magnetic flux decreases due to the attraction force additionally generated by the rotation of the rotor 20, so that the magnitude of the magnetic flux is increased to compensate for the reduction of the magnetic flux. By balancing the pore flux density, the output of the LSPM motor 100 can be improved and torque ripple can be improved, and the cogging torque can be reduced to improve vibration and noise characteristics.

At this time, the plurality of permanent magnets 22 are installed symmetrically with respect to the rotation shaft insertion hole 25, the neighboring permanent magnets 22 are different in size, but the permanent magnets 22 facing each other are arranged The size is the same as each other. The plurality of permanent magnets 22 may be formed to be relatively short in length compared to the lengths of the permanent magnets 22b and 22d, which have the lengths of the permanent magnets 22a and 22c that are advanced in the rotational direction of the rotation shaft 30. The width of the plurality of permanent magnets 22 may be the same.

For example, the plurality of permanent magnets 22 may include a plurality of first permanent magnets 28 forming an N pole and neighboring each other, and a plurality of second permanent magnets 29 forming the S pole and neighboring each other. have. The plurality of first permanent magnets 28 and the plurality of second permanent magnets 29 are installed on the rotor core 21 symmetrically with respect to the rotation shaft 20. Of course, the plurality of first permanent magnets 28 and the second permanent magnets 29 are relatively larger in size than the permanent magnets 22b and 22d, respectively. small.

In order to manufacture the permanent magnets 22a and 22c in the direction of rotation relatively smaller than the permanent magnets 22b and 22d in the direction of rotation, the permanent magnets 22a and 22c in the direction of rotation are permanent magnets 22b and 22d. It can be made shorter than the length of. The width of the plurality of permanent magnets 22 is the same. For example, in the plurality of first permanent magnets 28, the length a of the front permanent magnet 22a can be made shorter than the length b of the rear permanent magnet 22b.

As shown in FIG. 1, the plurality of first and second permanent magnets 28 and 29 may each be two. The angle between the pair of first permanent magnets 28 and the angle between the pair of second permanent magnets 29 are each 90 degrees or more, and the neighboring first permanent magnets 28 and the second permanent magnets 29 A plurality of first and second permanent magnets 28 and 29 may be inserted into the rotor iron core 21 so that an angle between the two poles is 90 degrees or less.

In the first embodiment, four permanent magnets 22 are arranged around the rotation shaft insertion hole 25, and the pair of first permanent magnets 28 form an N pole, and the pair of second permanent magnets is arranged. Although the case where (29) forms an S pole was demonstrated, it is not limited to this. For example, four or more even-numbered permanent magnets 22 may be inserted into the rotor iron cores 21, or a plurality of neighboring permanent magnets 22 may be inserted into the rotor iron cores 21 to have different polarities. .

On the other hand, the first embodiment discloses an example in which the lengths of the permanent magnets 22a and 22c in the rotational direction of the rotary shaft 30 are shorter than the lengths of the permanent magnets 22b and 22d in the reverse direction. It is not. For example, the widths of the permanent magnets 22a and 22c that are advanced in the rotational direction of the rotary shaft 30 can be formed relatively shorter than the widths of the permanent magnets 22b and 22d that are later. In this case, the plurality of permanent magnets 22 may have the same length. Alternatively, the lengths and widths of the permanent magnets 22a and 22c leading in the rotational direction of the rotary shaft 30 may be relatively shorter than the lengths and widths of the permanent magnets 22b and 22d.

In the first embodiment, when the length of the preceding permanent magnets 22a and 22c is made relatively short compared to the latter permanent magnets 22b and 22d, the preceding permanent magnets 22a and 22c form a short central portion of the magnetic pole. Although the example was disclosed, it is not limited to this. For example, the edge portions of the magnetic poles of the preceding permanent magnets 22a and 22c may be formed short. Alternatively, both ends of the preceding permanent magnets 22a and 22c may be formed short.

As described above, the rotor iron core 21 has a plurality of conductor bar insertion holes 27 formed around the outer edges of the plurality of permanent magnet insertion holes 26. Here, the plurality of conductor bar insertion holes 27 may be formed in a direction in which the permanent magnet insertion hole 26 is formed, that is, penetrating the rotor iron core 21. The plurality of conductor bar insertion holes 27 have an elongated shape and are disposed outside the rotor iron core 21. The conductor bar insertion hole 27 may be formed as a slot toward the permanent magnet 22. For example, the conductor bar insertion hole 27 may be formed in an elongated ellipse or an elongated rectangular shape in which both ends of the long side are convex outward. The spacing between the plurality of conductor bar insertion holes 27 may be formed substantially the same. The plurality of conductor bar insertion holes 27 may have a central length of the magnetic pole shorter than that of the edge of the magnetic pole (L1> L2). Preferably, the lengths of the plurality of conductor bar insertion holes 26 are gradually shortened from the center of the magnetic pole toward the edge.

The plurality of conductor bars 23 are inserted into and installed in the plurality of conductor bar insertion holes 27, respectively. The spacing between the plurality of conductor bars 23 may be formed substantially the same. The plurality of conductor bars 23 may be installed in the conductor bar insertion hole 27 by a die casting method. The conductor bar 23 may generally use an aluminum (Al) material having excellent electrical conductivity and capable of die casting. The conductor bar 23 formed by die casting is formed in a shape corresponding to the shape of the conductor bar insertion hole 27. At this time, the length of the plurality of conductor bars 23 is shorter than the edge portion of the magnetic pole by the plurality of conductor bar insertion holes 27 described above. By forming the plurality of conductor bars 23 in this manner, the distance between the permanent magnets 22 and the conductor bars 28 forming the magnetic poles is longer than the central portion of the magnetic poles.

The reason why the length L1 of the conductor bar 23 at the center of the magnetic pole formed by the permanent magnet 22 is shorter than the length L2 of the conductor bar 23 at the edge of the magnetic pole is shown in FIG. 3. As shown in FIG. 6, the pore flux density is focused to a central portion of the magnetic pole to realize the pore flux density in a sinusoidal shape. In other words, since the plurality of conductor bars are radially installed toward the center of the rotation shaft 30, the pore flux density between the rotor and the stator forms a square wave, and the cogging torque generated thereby increases vibration and noise. . On the other hand, as in the first embodiment, the length L1 of the conductor bar 23 in the center portion of the magnetic pole is formed to be shorter than the length L2 of the conductor bar 23 in the edge portion of the magnetic pole. Can be implemented. Therefore, the cogging torque generated when the LSPM motor 100 is driven according to the first embodiment may be reduced to reduce the generation of vibration and noise when the LSPM motor 100 is driven.

In particular, the length of the plurality of conductor bars 23 is inserted into the rotor core 21 which gradually decreases from the center of the magnetic pole toward the edge, so that the pore magnetic flux density is the highest in the central portion of the magnetic pole of the permanent magnet 22. As the pore flux density gradually decreases from the center of the magnetic pole toward the outside, the pore flux density can be realized closer to the sinusoidal shape.

The LSPM motor 100 according to the first embodiment is generated by the secondary current generated by the voltage induced in the conductor bar 23 of the rotor 20 and the winding 16 of the stator 10. The rotor 20 starts to rotate by the torque generated by the interaction of the magnetic fluxes, and is started and generated at the magnetic flux of the permanent magnet 22 installed in the rotor 20 and the stator 10 at the rated operation. The magnetic flux is synchronized with each other to operate at the speed of the rotor magnetic field of the stator 10. At this time, since the attraction force occurs in the rotational direction of the rotor 20 when the LSPM motor 100 is driven, the strength of the magnetic flux due to the attraction force additionally generated by the rotation of the rotor 20 in the preceding permanent magnet 22 In order to reduce the size and increase the size of the magnetic flux generated by the additional force generated by the rotation of the rotor 20 in the rear permanent magnet 22, the repulsive force is reduced by increasing the size to compensate for the magnetic flux reduction by This can solve the imbalance in the pore flux density.

In addition, the length L1 of the conductor bar 23 in the center portion of the magnetic pole formed by the permanent magnet 22 is shorter than the length L2 of the conductor bar 23 in the edge portion of the magnetic pole, thereby stimulating the void magnetic flux density. By focusing to the central part of, the pore magnetic flux density can be realized in a sinusoidal shape.

Meanwhile, in the first embodiment, an example in which the spacing between the plurality of conductor bars 23 is formed substantially the same is disclosed, but the present invention is not limited thereto. That is, as shown in FIG. 4, the distance d1 between the conductor bars 23 of the center portion of the magnetic pole formed by the plurality of permanent magnets 22 is the distance d2 between the conductor bars 23 of the edge portion of the magnetic pole. It can be formed rather wide.

4 is a plan view illustrating the rotor 120 of the LSPM motor according to the second exemplary embodiment of the present invention.

Referring to FIG. 4, the rotor 120 according to the second embodiment of the present invention has a distance d1 between the conductor bars 23 of the central portion of the magnetic pole formed by the plurality of permanent magnets 22. Since a plurality of conductor bars 23 have the same structure as that of the rotor (20 in FIG. 1) according to the first embodiment except that they are formed wider than the distance d2 between the conductor bars 23 of the portion, the plurality of conductor bars 23 are rotors. Referring to the structure installed in the iron core 21 as follows.

Here, the plurality of conductor bars 23 are inserted into and installed in the plurality of conductor bar insertion holes 27, respectively. The spacing between the plurality of conductor bars 23 is formed by the plurality of conductor bar insertion holes 27 described above so that the center portion of the magnetic pole is wider than the edge portion of the magnetic pole.

The reason why the space d1 between the conductor bars 23 in the center portion of the magnetic pole formed by the permanent magnet 22 is wider than the distance d2 between the conductor bars 23 in the edge portion of the magnetic pole is due to the void magnetic flux. This is to achieve the pore flux density in a sinusoidal shape by focusing the density to the center of the magnetic pole. As in the second embodiment, the length of the conductor bar 23 of the center portion of the magnetic pole formed by the permanent magnet 22 is shorter than the length of the conductor bar 23 of the edge portion of the magnetic pole, and at the same time By forming the space d1 between the conductor bars 23 wider than the space d2 between the conductor bars 23 at the edges of the magnetic poles, the pore magnetic flux density can be made closer to the sinusoidal shape. Accordingly, the cogging torque generated when the LSPM motor is driven according to the second embodiment can be reduced, thereby reducing the occurrence of vibration and noise when the LSPM motor is driven.

In particular, the spacing between the plurality of conductor bars 23 is inserted into the rotor core 21 so as to become narrower from the center of the magnetic pole toward the edge, so that the pore magnetic flux density is the highest in the central portion of the magnetic pole of the permanent magnet 22, Since the pore magnetic flux density can be gradually reduced from the center of the magnetic pole to the outer portion, the pore magnetic flux density can be realized closer to the sinusoidal shape.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of specific examples for the purpose of understanding and are not intended to limit the scope of the present invention. In addition to the embodiments disclosed herein, it is apparent to those skilled in the art that other modifications based on the technical idea of the present invention may be implemented.

10: Stator
11: stator iron core
12: stator iron plate
14: Tooth
16: coil
18: rotor insertion hole
20, 120: rotor
21: rotor iron core
22: permanent magnet
23: conductor bar
24: rotor iron plate
25: rotating shaft insertion hole
26: permanent magnet insertion hole
27: conductor bar insertion hole
100: LSPM Motor

Claims (8)

A rotor of an LSPM motor inserted into a rotor insertion hole of a stator and rotatably installed.
A rotation shaft insertion hole is formed in the center portion and the rotation shaft is inserted. A plurality of permanent magnet insertion holes are formed around the rotation shaft insertion hole, and a plurality of conductor bars are inserted around the outer side of the plurality of permanent magnet insertion holes. A rotor iron core in which holes are formed;
A plurality of permanent magnets respectively inserted into the plurality of permanent magnet insertion holes to form an N pole and an S pole;
And a plurality of conductor bars respectively inserted into and installed in the plurality of conductor bar insertion holes.
The length of the conductor bar of the central portion of the magnetic pole formed by the plurality of permanent magnets is formed shorter than the length of the conductor bar of the edge portion of the magnetic pole,
The plurality of permanent magnets,
Two first permanent magnets forming the N pole and neighboring each other;
And two second permanent magnets forming the S pole and neighboring each other.
The two first permanent magnets and the two second permanent magnets are each smaller in size than the permanent magnets that are preceded by the permanent magnets in the direction of rotation of the rotary shaft,
The two first permanent magnets and the two second permanent magnets are respectively formed in a relatively short length of the permanent magnet in the direction of rotation of the rotation axis compared to the length of the permanent magnet in the direction of the magnetic pole of the preceding permanent magnet. The short side is formed so that the distance between both ends of the two first permanent magnets facing each other and the distance between both ends of the two second permanent magnets facing each other between the both ends of the first and second permanent magnets adjacent to each other. The rotor of the LSPM motor, characterized in that formed wider than the interval of. The method of claim 1, wherein the plurality of permanent magnets,
The rotor of the LSPM motor, wherein the permanent magnets are installed symmetrically with respect to the rotation shaft insertion hole, and the permanent magnets facing each other have the same size, and neighboring permanent magnets have different sizes. delete The method of claim 2, wherein the plurality of permanent magnets,
Rotor of the LSPM motor, characterized in that the same width. 5. The method of claim 4,
The angle between the two first permanent magnets and the angle between the two second permanent magnets are each 90 degrees or more, and the angle between the neighboring first permanent magnets and the second permanent magnets is 90 degrees or less. Rotor of LSPM motor. The method of claim 1,
The length of the plurality of conductor bar is a rotor of the LSPM motor, characterized in that the smaller from the center of the magnetic pole toward the edge. The method of claim 1,
The rotor of the LSPM motor, characterized in that the spacing between the conductor bars of the central portion of the magnetic pole formed by the plurality of permanent magnets is wider than the interval between the conductor bars of the edge portion of the magnetic pole. The rotor according to any one of claims 1, 2, 4-7;
A stator in which a rotor insertion hole into which the rotor is inserted is formed at a central portion thereof, and a coil is wound around an inner circumferential surface of the rotor insertion hole;
LSPM motor comprising a.

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