KR20070092838A - Rotor of a line start permanent magnet synchronous motor - Google Patents

Abstract

A rotor of an LSPM(Line Start Permanent Magnet) synchronous motor is provided to reduce torque ripples by arranging both ends of permanent magnets of different poles adjacently to each other in a rotor core. A rotor of an LSPM synchronous motor includes a rotor core(110), and a plurality of permanent magnets(120). The rotor core(110) has a shaft hole(111) at a center, and a plurality of conductors(114) along a circumference. The plurality of permanent magnets(120) are inserted around the shaft hole(111) of the rotor core(110). Both ends of the permanent magnets(120) of different poles are arranged to be adjacent to each other so that the change of polarity of induction voltage induced to the rotor core(110) is decreased to reduce torque ripples.

Description

ROTOR OF A LINE START PERMANENT MAGNET SYNCHRONOUS MOTOR

1 is a plan view showing the main part of the LSPM synchronous motor according to the prior art,

2 is a graph illustrating a change in secondary voltage of an LSPM synchronous motor according to the related art.

3 is a plan view showing a permanent magnet of the LSPM synchronous motor according to the first embodiment of the present invention;

4 is a plan view illustrating a permanent magnet of an LSPM synchronous motor according to a second embodiment of the present invention;

5 is a graph showing the secondary voltage change of the LSPM synchronous motor according to the present invention.

<Description of Symbols for Main Parts of Drawings>

110, 210: rotor core 111, 211: shaft hole

112, 212: magnet mounting holes 113, 213: conductor insertion holes

114, 214: conductors 120, 220: permanent magnets

The present invention relates to a rotor of an LSPM synchronous motor, and more particularly, to a rotor of an LSPM synchronous motor having an improved arrangement of permanent magnets to bring torque continuity during driving.

In general, a motor is a device that obtains rotational force by converting electrical energy into mechanical energy, and is widely used in home appliances as well as industrial equipment. The motor is largely divided into an AC motor and a DC motor.

On the other hand, LSPM Line Start Permanent Magnet Synchronous Motor, which is a kind of AC motor, has a mutual relation between the secondary current generated by the voltage induced in the conductor of the rotor and the magnetic flux generated by the winding of the stator. Driven by the torque generated by the action, the torque is started by the combined torque of the torque line segment and reluctance torque and the magnet torque by the cage. At the time of starting and 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 rotating magnetic field.

Referring to the conventional LSPM synchronous motor with reference to the accompanying drawings as follows.

1 is a plan view showing the main part of the LSPM synchronous motor according to the prior art. As shown, the conventional LSPM synchronous motor 10 has a stator 11 fixed to a casing or a shell, not shown, and a coil 12 wound around the stator 11. And a rotor 13 rotatably installed with a gap in the stator 11.

The stator 11 is formed by stacking a large number of silicon steel sheets having the same shape in an axial direction, and holes (not shown) are formed to place the rotor 13 inside, and a plurality of teeth 11a are spaced at regular intervals along the inner circumferential surface. Is formed to form slots 11b between the teeth 11a.

The coil 12 is wound around each of the teeth 11a to generate a rotating magnetic flux due to the structure of the stator 11 when the AC power is applied.

The rotor 13 is rotatably installed with a gap in the center of the stator 11, and the shaft 13a is fixed through an insertion hole (not shown) formed at the center, and has a bar shape along the edge. A plurality of conductors 13b are inserted and fixed vertically, a plurality of mounting holes 13c are formed around the shaft 13a, and a permanent magnet 13d is inserted and fixed to each of the mounting holes 13c.

The shaft 13a is rotatably installed through a bearing (not shown) in a casing or a shell forming the case of the LSPM synchronous motor 10, and the conductor 13b is generally made of aluminum having excellent conductivity and capable of die casting. Al is used, and the permanent magnet 13d generates torque by interaction with the magnetic flux generated in the coil 12.

In the conventional LSPM synchronous motor 10, when a current is applied to the coil 12, the rotational flux generated by the stator 11 and the induced current generated in the conductor 13b of the rotor 13 are generated. The rotor 13 is rotated by the interaction. When the rotor 13 reaches the synchronous speed, torque due to the permanent magnet 13d and reluctance torque due to the structure of the rotor 13 are generated, and the rotor 13 rotates.

However, the conventional LSPM synchronous motor 10 has a secondary voltage induced at the rotor 13 side when the pole of the magnetic flux changes, that is, as shown in FIG. 2, as shown in FIG. 2. Torque ripple occurs at the "a" site where the pole of the permanent magnet 13d changes, which is particularly severe due to the gap between the permanent magnets 13d arranged in a rhombic shape. The torque ripple causes the rotor 13 to vibrate, and this vibration not only causes noise but also causes a decrease in efficiency.

Therefore, it is necessary to minimize the occurrence of the torque ripple generated from the LSPM synchronous motor 10 to minimize the occurrence of vibration and noise, as well as to develop a product that improves the efficiency.

The present invention is to solve the above-mentioned problems, an object of the present invention by improving the arrangement structure of the permanent magnet, by suppressing the occurrence of torque ripple during driving to minimize the generation of vibration and noise, LSPM to improve efficiency It is to provide a rotor of a synchronous motor.

In order to achieve the above object, the present invention provides a LSPM synchronization including a rotor core having a shaft hole formed at a center thereof and a plurality of conductors inserted along an edge thereof, and a plurality of permanent magnets inserted into the rotor core around the shaft hole. In the rotor of the motor, both ends of the permanent magnets having different poles are disposed close to each other so as to reduce torque ripple by alleviating the change in the polarity of the induced voltage induced in the rotor core. It is characterized by providing a rotor of the LSPM synchronous motor.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

3 is a plan view illustrating a rotor of the LSPM synchronous motor according to the first embodiment of the present invention. As shown, the rotor 100 of the LSPM synchronous motor according to the first embodiment of the present invention is rotatably installed with a gap in the stator 11 (shown in FIG. 1), and the shaft hole 111 in the center thereof. The rotor core 110 includes a plurality of conductors 114 inserted into the edge and a plurality of permanent magnets 120 inserted into the rotor core 110 around the shaft hole 111.

The rotor core 110 may be formed by lamination of a plurality of silicon steel sheets, or may be formed by a compression process of soft magnetic power.

When the rotor core 110 is compression-molded with soft magnetic powder, the molding machine provides a molding space including a shape corresponding to the rotor core 110, fills the molding space with soft magnetic powder, and then compresses it with a compression member such as a punch. By compressing, the shaft hole 111, the magnet mounting hole 112, and the conductor insertion hole 113 are simultaneously formed.

The soft magnetic powder used for the manufacture of the rotor core 110 is based on iron-based particles, coated with each of the particles to be electrically insulated, and compressed together containing a lubricant and / or a binder during compression. Can be.

The rotor core 110 becomes a soft magnetic composite (also referred to as "SMC") having a three-dimensional shape by a compression process of the soft magnetic powder, and has a higher degree of freedom than the conventional case using a silicon steel sheet. By allowing freedom, the magnet mounting hole 112 and the conductor insertion hole 113, as well as the silicon steel laminated structure having only the same shape in the related art, facilitate the formation of various shapes.

The rotor core 110 has a shaft hole 111 for vertically inserting and fixing a shaft 13a (shown in FIG. 1) at the center thereof, and a plurality of conductor insertion holes 113 formed at regular intervals along an edge thereof. The conductor 114 of a material having excellent conductivity, such as aluminum (Al), is inserted and fixed by die casting or the like, and by reducing the polarity change of the induced voltage induced in the rotor core 110 according to the characteristics of the present invention. In order to reduce torque ripple, both ends of the permanent magnets 120 having different poles from each other are disposed in close proximity to each other in the rotor core 110.

For example, the permanent magnet 120 is disposed in a rhombic shape around the shaft hole 111, the end of the other permanent magnet 120 on one end side of the permanent magnet 120 is located close to the orthogonal direction In order to be arranged alternately with each other in succession. Permanent magnets 120 are inserted into each of the magnet mounting holes 112 of this type and are fixed to the rotor core 110 around the shaft hole 111.

Therefore, the permanent magnet 120 is vertically inserted into each of the magnet mounting holes 112 so that the secondary is induced on the rotor core 110 by the primary induced voltage induced from the stator 11 (shown in FIG. 1). The induced current is generated by the continuous magnetic flux of the permanent magnets 120 continuously arranged in close proximity to the induced voltage, thereby reducing torque ripple by mitigating the polarity change of the secondary induced voltage induced in the rotor core 110.

As shown in FIG. 4, in the rotor 200 of the LSPM synchronous motor according to the second embodiment, a bent portion 222 is formed by bending any one end of both ends of the permanent magnet 220 at right angles. The non-bent end of the other permanent magnets 220 are arranged in close proximity to the inside of the part 222, and a plurality of the permanent ends of the permanent magnets 220 are continuously disposed along the shape of the shaft hole 111. In addition, the permanent magnets 220 having the bent portions 222 are inserted into each of the “a” -shaped magnet mounting holes 112, thereby being fixed to the rotor core 210 around the shaft hole 111.

The rotor of the LSPM synchronous motor having such a structure is performed as follows.

LSPM motor according to the present invention is the rotor core (110, 210) side by the primary induced voltage generated by applying power to the coil 12 (shown in Figure 1) wound on the stator 11 (shown in Figure 1) during driving The secondary induced voltage is induced, and at this time, the ends of the permanent magnets 120 and 220 having different poles are disposed close to each other so that the polarity of the induced voltage induced in the rotor cores 110 and 210, that is, as shown in FIG. 5. The continuity of the magnet in the "b" part where the polar change of the magnetic flux occurs to mitigate the polarity change of the induced voltage (V ₂ ), thereby greatly reducing the torque ripple, thereby suppressing vibration and noise, and improving efficiency.

As described above, the rotor of the LSPM synchronous motor according to the present invention has an effect of minimizing the generation of vibration and noise by suppressing the occurrence of torque ripple during driving, by improving the arrangement structure of the permanent magnet, improving the efficiency .

What has been described above is just one embodiment for implementing the rotor of the LSPM synchronous motor according to the present invention, the present invention is not limited to the above embodiment, as claimed in the following claims of the present invention Without departing from the gist of the present invention, one of ordinary skill in the art will have the technical spirit of the present invention to the extent that various modifications can be made.

Claims (4)

In the rotor of the LSPM synchronous motor having a shaft hole is formed in the center, the rotor core including a plurality of conductors are inserted along the edge, and a plurality of permanent magnets inserted into the rotor core around the shaft hole, In order to reduce torque ripple by alleviating the change in polarity of the induced voltage induced in the rotor core, both ends of the permanent magnets having different poles are disposed close to each other in the rotor core so as to face each other. Rotor. The method of claim 1, The rotor core, Formed by compression of soft magnetic powder Rotor of the LSPM synchronous motor, characterized in that. The method of claim 1, One end of the other permanent magnet on the one end side of the permanent magnet is arranged in a plurality in the vicinity of the shaft hole in a structure that is located in the orthogonal direction, Rotor of the LSPM synchronous motor, characterized in that. The method of claim 1, Any one end of the permanent magnet is bent at a right angle to a plurality of arranged around the shaft hole in a structure including one end of the other facing facing the permanent magnet, Rotor of the LSPM synchronous motor, characterized in that.

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