KR101260689B1 - Rotor and synchronous motor having the rotor - Google Patents

Abstract

PURPOSE: A rotor including permanent magnets having different thicknesses and a synchronous motor including thereof are provided to include a plurality of permanent magnets which has different thicknesses according to the distance from the center of a magnet pole, of which the relatively thick portion is disposed at the center of the magnetic pole and the relatively thin portion is disposed on the edge of the magnetic pole, thereby generating high magnetic flux in the central part. CONSTITUTION: A rotor(20) is rotatably installed by being inserted into a rotor insertion hole of a stator. The rotor includes a rotor iron core(21), a plurality of permanent magnets, and a plurality of conductor bars(23). The rotor iron core has a rotating shaft insertion hole(25) at the center; a plurality of permanent magnet insertion holes which is formed on the circumference of the rotating shaft insertion hole; and a plurality of conductor bar insertion holes which is formed on the circumference of the magnet insertion holes. Each of the permanent magnets is respectively inserted into the permanent magnet insertion holes for forming an N pole and an S pole. Each of the conductor bars is respectively inserted into the conductor bar insertion holes.

Description

Rotor and synchronous motor having the rotor

The present invention relates to a synchronous motor, and more particularly, a permanent magnet having a different thickness at both ends is inserted into a rotor core, and the length of the conductor bar of the center and the edge of the magnetic pole is adjusted to adjust the pore magnetic flux density. The present invention relates to a rotor having a conductor bar having a different length from a permanent magnet having a different thickness and that can be embodied in a sine curve) and a 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 Linear Start Permanent Magnet (LSPM) motors (also known as 'single-phase induction synchronous motors'), are AC motors that apply 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, it is an object of the present invention to provide a rotor having a permanent magnet having a different thickness and a motor having the same, which have excellent vibration and noise characteristics by reducing cogging torque.

Another object of the present invention is to implement a rotor flux density and a sine curve shape to reduce the cogging torque and minimize the torque ripple to improve the vibration and noise characteristics of the rotor having a permanent magnet having a different thickness and including the same To provide a motor.

In order to achieve the above object, the present invention provides a rotor including a rotor iron core, a plurality of permanent magnets and a plurality of conductor bars as a rotor of a motor inserted into the rotor insertion hole of the stator to be rotatably installed. . 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 rotor poles of 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. At this time, the rotor poles of the N pole and the rotor poles of the S pole are each formed with the same number of permanent magnets. Each of the plurality of permanent magnets has a different thickness according to a distance from the center of the rotor poles, and a portion thickly formed on the center side of the rotor poles is disposed, and a portion formed thinly on the edge side of the rotor poles. Is done. In addition, the spacing between the conductor bars of the center portion of the rotor poles formed by the plurality of permanent magnets is wider than the spacing between the conductor bars of the edge portion of the rotor poles.

In the rotor of the motor according to the present invention, the plurality of permanent magnets are installed symmetrically with respect to the rotation axis insertion hole, the cross section perpendicular to the rotation axis has a trapezoidal shape, facing the rotation shaft insertion hole The viewing side may be longer than the adjacent side and the side facing the rotation shaft insertion hole.

In the rotor of the motor according to the present invention, the plurality of permanent magnets, respectively, the first side facing the rotation shaft insertion hole, the second side facing the first side, the first side and the second side A third side that connects one end to each other and is shorter than the first and second sides and is disposed at a central portion of the rotor pole, and connects the other ends of the first and second sides to each other, It is short and includes a fourth side disposed at the edge of the rotor pole.

In the rotor of the motor according to the present invention, the plurality of permanent magnets form an N pole of the rotor poles and a pair of first permanent magnets adjacent to each other, and form a S pole of the rotor poles and each other It may include a pair of neighboring second permanent magnets. In this case, the pair of first permanent magnets are disposed on the side facing each other thickly formed, the thin portion formed on the opposite side. The pair of second permanent magnets are disposed on the side facing each other thickly formed, the opposite side is formed thinly formed.

In the rotor of the motor according to the present invention, the angle formed by the pair of first permanent magnets and the angle formed by the pair of second permanent magnets are obtuse angles, and one adjacent first permanent magnet and one The angle formed by the second permanent magnet may be an acute angle.

In the rotor of the 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 rotor pole.

In the rotor of the motor according to the present invention, the spacing between the conductor bar insertion holes in the center portion of the rotor poles formed by the plurality of permanent magnets is greater than the spacing between the conductor bar insertion holes in the edge portion of the rotor poles. It can be formed widely.

In addition, the present invention, the rotor described above, and a rotor insertion hole in which the rotor is inserted in the center portion is formed, the permanent permanently of different thickness including a stator with a coil wound around the inner peripheral surface of the rotor insertion hole Provided is a motor having a magnet.

According to the present invention, when the permanent magnet is inserted into the iron core of the rotor, the center portion of the magnetic pole is disposed so that the thickly formed portion and the edge portion of the magnetic pole are disposed so that the magnetic flux density is formed into a sinusoidal shape. By implementing cogging torque and minimizing torque ripple, vibration and noise characteristics can be improved.

In other words, when a plurality of permanent magnets are placed on the rotor core, the magnetic poles are thicker at the center and thinner at the edges of the poles, thereby generating higher magnetic flux at the center of the poles than at the edges of the poles. Therefore, by making the pore magnetic flux density into a sinusoidal shape, it is possible to reduce the cogging torque and torque ripple of the synchronous motor, thereby minimizing the generation of vibration and noise when driving the synchronous motor.

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 driving the synchronous motor, thereby reducing the generation of vibration and noise when driving the synchronous motor.

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 a synchronous motor having a conductor bar having a different length from a permanent magnet having a different thickness according to a first embodiment of the present invention.
FIG. 2 is a plan view illustrating a synchronous motor having the rotor of FIG. 1.
FIG. 3 is a view schematically showing a pore magnetic flux density and a waveform diagram according to the rotor structure of FIG. 1.
1 is a plan view showing a rotor of a synchronous motor having a conductor bar having a length different from that of a permanent magnet having a different thickness according to a second embodiment of the present invention.

In the following description, only parts necessary for understanding the embodiments of the present invention will be described, and the description of other parts will be omitted so as not to obscure the gist of the present invention.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings and the inventor is not limited to the meaning of the terms in order to describe his invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configuration shown in the drawings are only preferred embodiments of the present invention, and do not represent all of the technical idea of the present invention, and various equivalents may be substituted for them at the time of the present application. It should be understood that there may be variations and variations.

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 a synchronous motor having a conductor bar 23 having a different thickness from a permanent magnet 22 having a different thickness according to a first embodiment of the present invention. FIG. 2 is a plan view illustrating a synchronous 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 synchronous 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. do. 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 synchronous motor 100 via a bearing.

The rotor 20 is a rotor of the synchronous motor 100 inserted into the rotor insertion hole of the stator and rotatably installed, and the rotor 20 and the plurality of rotors embedded in the rotor core 21 are provided. Permanent magnet 22, and a plurality of conductor bar (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, each of the plurality of permanent magnets 22 has a different thickness according to the distance from the center of the magnetic pole, and a thick portion (b) is disposed on the center of the magnetic pole and a thin portion (a) is disposed on the edge of the magnetic pole. do. 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. Here, the magnetic poles formed by the plurality of permanent magnets 22 mean rotor magnetic poles.

As described above, when the rotor 20 according to the first embodiment is installed with the permanent magnet 22 inserted into the rotor iron core 21, a part b formed in the center of the magnetic pole is thickly disposed and the edge of the magnetic pole is thinner. Since the formed portion (a) is inserted and installed, the pore magnetic flux density can be implemented in a sinusoidal shape, thereby reducing cogging torque and minimizing torque ripple, thereby improving vibration and noise characteristics.

That is, when the plurality of permanent magnets 22 are disposed on the rotor core 21, the magnetic poles are thicker at the center of the magnetic pole and thinner at the edges of the magnetic poles. High magnetic flux can be generated in the center of the. Therefore, by making the pore magnetic flux density of the motor having the rotor 20 according to the first embodiment into a sinusoidal shape, it is possible to reduce the cogging torque and torque ripple of the motor. Through this, it is possible to minimize the generation of vibration and noise when driving the motor.

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 synchronous motor 100 is driven, thereby reducing the occurrence of vibration and noise when the synchronous motor 100 is driven. have.

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.

In the first embodiment, four permanent magnet insertion holes 26 are provided in which the permanent magnets 22 are provided with a square cross section with respect to the axial direction of the rotation shaft insertion holes 25 on the outer side of the rotation shaft insertion holes 25. Although the example provided in the electron iron core 21 was disclosed, it is not limited to this. For example, the permanent magnet insertion hole 26 may have a trapezoidal cross section with respect to the axial direction of the rotation shaft insertion hole 25.

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. As the permanent magnet 22, a rare earth magnet may be used.

In particular, the plurality of permanent magnets 22 have a thick portion (b) disposed on the center of the magnetic pole and a thin portion (a) disposed on the edge of the magnetic pole in order to solve the imbalance of void magnetic flux density. It is inserted into the hole 26 and installed. The reason why the plurality of permanent magnets 22 are arranged in this way is to generate a high magnetic flux at the center of the magnetic pole as compared with the edge of the magnetic pole and to make the void magnetic flux density into a sinusoidal shape. By making the pore flux density into a sinusoidal shape, it is possible to reduce the cogging torque and torque ripple of the motor, thereby minimizing the generation of vibration and noise when the motor is driven.

At this time, the plurality of permanent magnets 22 are installed symmetrically with respect to the rotation shaft insertion hole 25, the cross section perpendicular to the rotation shaft 30 may have a trapezoidal shape. The plurality of permanent magnets 22 have a longer length than the other side facing the rotation shaft insertion hole 25. That is, the plurality of permanent magnets 22 may have a first side 41, a second side 42, a third side 43, and a fourth side 44, respectively. At this time, the first side 41 faces the rotation shaft insertion hole 25. The second side 42 faces the first side 41. The third side 43 connects one end of the first side 41 and the second side 42 to each other, and is shorter than the first and second sides 41 and 42 and is disposed at the central portion of the magnetic pole. . The fourth side 44 connects the other ends of the first side 41 and the second side 42 to each other, is shorter than the third side 43, and is disposed at the edge portion of the magnetic pole. In this case, the plurality of permanent magnets 22 may have a trapezoidal shape in which the third side 43 and the fourth side 44 are parallel to each other.

For example, the plurality of permanent magnets 22 includes a pair of first permanent magnets 28 forming an N pole and neighboring each other, and a pair of second permanent magnets 29 forming the S pole and adjacent to each other. can do. The pair of first permanent magnets 28 and the pair of second permanent magnets 29 are installed on the rotor core 21 symmetrically with respect to the rotation shaft 30. Of course, the pair of first permanent magnets 28 are disposed to face each other thickly formed portion (b), the opposite side is formed a thin portion (a) is disposed. In addition, the pair of second permanent magnets 29 are thickly formed on the side facing each other (b), the opposite side is formed a thin portion (a) is disposed. In this case, the angle between the pair of first permanent magnets 28 and the pair of second permanent magnets 29 is an obtuse angle, and the angle between the neighboring first permanent magnets 28 and the second permanent magnets 29 is It may be arranged at an acute angle. That is, the angle formed by the pair of first permanent magnets 28 and the angle formed by the pair of second permanent magnets 29 are obtuse angles, and one adjacent first permanent magnet 28 and one second The angle formed by the permanent magnet 29 is an acute angle.

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, in the first embodiment, the permanent magnet has illustrated a trapezoidal shape in which the third side 43 and the fourth side 44 are parallel to each other, but are not limited thereto. For example, the third side 43 and the fourth side 44 may not be parallel to each other. Of course, the third side 43 is formed thicker than the fourth side (a <b).

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. Spaces between the plurality of conductor bar insertion holes 27 may be uniformly formed. 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.

In addition, the plurality of conductor bars 23 are inserted into and installed in the plurality of conductor bar insertion holes 27, respectively. Spaces between the plurality of conductor bars 23 may be formed to be constant. 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 synchronous motor 100 is driven according to the first embodiment may be reduced to reduce the occurrence of vibration and noise when the synchronous 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 synchronous motor 100 according to the first exemplary embodiment includes a secondary current generated by a voltage induced by the conductor bar 23 of the rotor 20 and a winding 16 of the stator 10. The rotor 20 starts to rotate by the torque generated by the interaction of the generated magnetic flux, and starts and rotates 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 generated is synchronized with each other to operate at the speed of the rotating magnetic field of the stator 10.

At this time, when the plurality of permanent magnets 22 are inserted into and installed on the rotor core 21, a thickly formed portion (b) is disposed at the center of the magnetic pole and a thinly formed portion (a) is disposed at the edge of the magnetic pole. By inserting and installing, the pore flux density can be implemented in a sinusoidal shape to reduce cogging torque and minimize torque ripple, thereby improving vibration and noise characteristics.

That is, when the plurality of permanent magnets 22 are inserted into and installed on the rotor iron core 21, a thickly formed portion is disposed at the center of the magnetic pole and a thinly formed portion is disposed at the edge of the magnetic pole. As can be seen, high magnetic flux can be generated in the central portion of the magnetic pole as compared to the edge portion of the magnetic pole, thereby making the pore magnetic flux density sinusoidal. At this time, in the waveform diagram of Figure 4, the horizontal axis represents the angle (θ), the vertical axis represents the magnetic flux density (B). Referring to FIG. 4, it is possible to confirm that the pore magnetic flux density is implemented in a sinusoidal shape by inserting a permanent magnet having a different thickness into the rotor 20.

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.

On the other hand, although the example in which the space | interval between the some conductor bar 23 was formed constant was disclosed in 1st Embodiment, it is not limited to this. 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 showing the rotor 120 of the synchronous motor according to the second 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. Therefore, the cogging torque generated when driving the synchronous motor according to the second embodiment can be reduced, thereby reducing the occurrence of vibration and noise when driving the synchronous motor.

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.

On the other hand, the embodiments disclosed in the specification and drawings are merely presented specific examples to aid understanding, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

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: motor

Claims (8)

A rotor of a 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 rotor poles of the N pole and the S pole;
And a plurality of conductor bars respectively inserted into and installed in the plurality of conductor bar insertion holes.
The rotor poles of the N pole and the rotor poles of the S pole are each formed by the same number of permanent magnets, and the plurality of permanent magnets each have a different thickness depending on a distance from the center of the rotor poles. A thickly formed portion is disposed on the center side of the rotor poles, a thinly formed portion is disposed on the edge side of the rotor poles, and the length of the conductor bar of the center portion of the rotor poles formed by the plurality of permanent magnets is the The rotor of the motor having a permanent magnet of a different thickness, characterized in that formed shorter than the length of the conductor bar of the edge portion of the electromagnetic pole. The method of claim 1, wherein the plurality of permanent magnets,
It is installed symmetrically with respect to the rotation shaft insertion hole, the cross section perpendicular to the rotation axis has a trapezoidal shape, the side facing the rotation shaft insertion hole is longer than the side facing the rotation shaft insertion hole and the neighboring side. A rotor of a motor having permanent magnets of different thicknesses. The method of claim 1, wherein each of the plurality of permanent magnets,
A first side facing the rotation shaft insertion hole,
A second side facing the first side;
A third side connecting one end of the first side and the second side to each other, shorter than the first and second sides, and disposed at a central portion of the rotor pole;
A fourth side connecting the other ends of the first side and the second side to each other, shorter than the third side, and disposed at an edge portion of the rotor pole;
Rotor of the motor having a permanent magnet of a different thickness, characterized in that it comprises a. The method of claim 2, wherein the plurality of permanent magnets,
A pair of first permanent magnets forming an N pole of the rotor poles and adjacent to each other;
And a pair of second permanent magnets forming S poles of the rotor poles and adjacent to each other.
The pair of first permanent magnets are disposed on the side facing each other thickly formed, the opposite side is formed thinly formed,
The pair of second permanent magnets are disposed on the side facing each other thickly formed portion, the opposite side is formed a thinner portion of the rotor of the motor having a permanent magnet of a different thickness. 5. The method of claim 4,
An angle formed by the pair of first permanent magnets and an angle formed by the pair of second permanent magnets is an obtuse angle, and an angle formed by one neighboring first permanent magnet and one second permanent magnet is an acute angle. The rotor of the motor having a permanent magnet of a different thickness, characterized in that. The method of claim 1,
The length of the plurality of conductor bars is a rotor of a motor having a permanent magnet of a different thickness, characterized in that the smaller from the center of the rotor pole toward the edge. The method of claim 1,
The distance between the conductor bars of the center portion of the rotor magnetic pole formed by the plurality of permanent magnets is wider than the distance between the conductor bars of the edge portion of the rotor magnetic pole of the motor having a permanent magnet of a different thickness Rotor. With a rotor;
And a stator in which a rotor insertion hole into which the rotor is inserted in a center portion is formed, and a coil is wound around an inner circumferential surface of the rotor insertion hole.
The rotor
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 rotor poles of the N pole and the S pole;
And a plurality of conductor bars respectively inserted into and installed in the plurality of conductor bar insertion holes.
The rotor poles of the N pole and the rotor poles of the S pole are each formed by the same number of permanent magnets, and the plurality of permanent magnets each have a different thickness depending on a distance from the center of the rotor poles. A thickly formed portion is disposed on the center side of the rotor poles, a thinly formed portion is disposed on the edge side of the rotor poles, and the length of the conductor bar of the center portion of the rotor poles formed by the plurality of permanent magnets is the A synchronous motor having a permanent magnet of a different thickness, characterized in that formed shorter than the length of the conductor bar of the edge portion of the electromagnetic pole.

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