KR20180089204A - Electric motor with variable magnet and clothes treating apparatus having the same - Google Patents

Abstract

The present invention relates to a motor with a variable magnet and a clothes treating apparatus having the same. According to the present invention, the motor with a variable magnet comprises: a stator having a stator coil; and a rotor rotatably spaced apart from the stator with a gap therebetween. The rotor includes a rotor core; a stationary magnet disposed along a radial direction of the rotor core and spaced apart in a circumferential direction; and the variable magnet having coercive force smaller than coercive force of the stationary magnet and disposed along the circumferential direction of the rotor core to be closer to the gap than the stationary magnet. The variable magnet is configured so that magnetic force can be varied by magnetic force generated by the stator coil when a preset current is applied to the stator coil. Accordingly, operation efficiency can be improved at the time of low-speed operation or high-speed operation.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor having a variable magnet,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a motor having a variable magnet and a garment processing apparatus having the same.

As is well known, the clothes processing apparatus is a kind of apparatus for treating (washing, rinsing, dewatering, drying) clothes (or laundry) through a washing process, a rinsing process, a dewatering process and / or a drying process.

The clothes include not only clothes but also washable articles such as bedclothes such as futons, curtains, stuffed toys and the like.

The clothes processing apparatus generally comprises a cabinet, a drum provided inside the cabinet, and a motor for rotating the drum.

The motor means an apparatus for converting electrical energy into mechanical energy, as is well known.

The motor includes a stator and a rotor arranged to be movable relative to the stator.

However, in such a conventional garment processing apparatus, since the required characteristics of the motor during low-speed operation and high-speed operation are different from each other, when the required characteristics of one side are satisfied, the required characteristics of the other side are insufficient, .

In consideration of such a problem, a motor capable of variable speed operation by partly magnetizing or magnetizing a part of the permanent magnet of the rotor has been proposed.

However, in such a conventional motor, the output of the motor is greatly influenced by the material of the permanent magnet to be magnetized or demagnetized, so that the limit for the magnet material (magnetic material) forming the permanent magnet to be magnetized or demagnetized .

In addition, since the permanent magnet to be magnetized or demagnetized needs to use an expensive permanent magnet, the manufacturing cost is increased.

In addition, there is a problem that the magnetization efficiency and / or the demagnetization efficiency of the permanent magnet is low during magnetization or demagnetization, thereby increasing current consumption.

In addition, there is a problem that the number of permanent magnets to be magnetized or demagnetized is relatively small, so that the torque change due to magnetization and / or magnetization is insufficient.

KR 101398702 B1 (May 27, 2014). Announcement)

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a motor having a variable magnet capable of improving the operating efficiency during low-speed operation or high-speed operation, and a garment processing apparatus having the same.

Another object of the present invention is to provide a motor provided with a variable magnet capable of enhancing magnetizing efficiency at a low cost and a clothes processing apparatus having the same.

It is still another object of the present invention to provide a motor provided with a variable magnet capable of increasing the variation width of torque by increasing the number of variable magnets and a garment processing apparatus having the same.

In order to achieve the above object, the present invention provides a stator having a stator coil; And a rotor rotatably and spaced apart with an air gap relative to the stator, the rotor comprising: a rotor core; A stationary magnet disposed along the radial direction of the rotor core and spaced apart in the circumferential direction; And a variable magnet having a coercive force smaller than that of the stationary magnet and disposed along the circumferential direction of the rotor core so as to be closer to the gap than the stationary magnet, And the magnetic force is varied by a magnetic force generated by the stator coil upon application of the permanent magnet.

According to an embodiment of the present invention, the stationary magnets and the variable magnets are alternately disposed with mutually different magnetic poles along the circumferential direction, and when the central variable magnet among the three continuously variable magnets is magnetized, The directions of the magnetic lines of force and the directions of the magnetic lines of force of the fixed magnet provided on both sides of the variable magnet on both sides of the central variable magnet and on the both sides of the central variable magnet are arranged to coincide with each other.

According to an embodiment of the present invention, the rotor core includes a plurality of divided cores spaced apart at predetermined intervals along the circumferential direction.

According to an embodiment of the present invention, the plurality of divided cores includes: a divided core body; And a stationary magnet support unit configured to support the stationary magnets on both sides of the divided core body along the circumferential direction.

According to an embodiment of the present invention, the stationary magnet supporting portion includes a stationary magnet supporting rib that protrudes from the divided core body along the radial direction and is bent along the circumferential direction to surround the corner of the stationary magnet.

According to an embodiment of the present invention, the plurality of divided cores includes: a divided core body; And a variable magnet support unit configured to support the variable magnet in a region close to the gap of the divided core body.

According to an embodiment of the present invention, the variable magnet support portion is formed by projecting along the circumferential direction from both side edges of the corners of the divided core body near the gap, and being bent toward the gap along the radial direction, And a variable magnet supporting rib which surrounds both ends of the magnet, respectively.

According to an embodiment of the present invention, the rotor further includes a molding part formed by molding to surround the outer surfaces of the plurality of divided cores.

According to an embodiment of the present invention, the variable magnet is configured to have a thickness smaller than that of the fixed magnet.

According to an embodiment of the present invention, the variable magnet is configured to be extended by the stator coil before the rotor is rotated at a predetermined first speed.

According to an embodiment of the present invention, the variable magnet is configured to be magnetized by the stator coil before the rotor is rotated at a second speed higher than the first speed.

According to another aspect of the present invention, there is provided a cabinet comprising: a cabinet; A drum rotatably installed in the cabinet; And a motor having the variable magnet for rotating the drum.

As described above, according to the embodiment of the present invention, the torque of the variable magnet is increased during the low-speed operation and the torque of the variable magnet is decreased during the high-speed operation, .

Further, the stationary magnets are disposed along the radial direction, and the variable magnets are disposed closer to the gap than the stationary magnets, and the effect of increasing the size of the variable magnets is increased by the magnetic flux of the stationary magnets, thereby eliminating the use of expensive permanent magnets can do.

Thereby, the increase in torque can be increased by using relatively inexpensive commercial magnets.

Further, since the number of fixed magnets and the number of variable magnets are the same, the variation width (increase and decrease) of the torque can be increased.

Thus, both the low-speed high-torque operation and the high-speed low-torque operation can be performed.

1 is a sectional view of a clothes processing apparatus according to an embodiment of the present invention,
Fig. 2 is an enlarged view of a motor region having the variable magnet of Fig. 1,
3 is an exploded perspective view of the stator and rotor of FIG. 2,
Fig. 4 is a partially enlarged plan view of the stationary magnet and the variable magnet region of Fig. 2,
5 is an enlarged view of the main part of Fig. 4,
FIG. 6 is a cross-sectional view of the stationary magnet of FIG. 5,
Fig. 7 is a cross-sectional view of the variable magnet of Fig. 5,
8 is an enlarged view of the divided core of Fig. 5,
Fig. 9 is a control block diagram of the clothes processing apparatus of Fig. 1,
FIG. 10 is a view for explaining the operation of the variable magnet of FIG.
11 is a view for explaining the operation of the variable magnet of FIG.

Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings. In this specification, the same or similar reference numerals are given to the same or similar components in different embodiments, and the description thereof is replaced with the first explanation. As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. In the following description of the embodiments of the present invention, a detailed description of related arts will be omitted when it is determined that the gist of the embodiments disclosed herein may be blurred. In addition, it should be noted that the attached drawings are only for easy understanding of the embodiments disclosed in the present specification, and should not be construed as limiting the technical idea disclosed in the present specification by the attached drawings.

1 and 2, a clothes processing apparatus according to an embodiment of the present invention includes a cabinet 110; A drum 130 rotatably installed in the cabinet 110; And a motor 150 having a variable magnet according to an embodiment of the present invention for rotating and driving the drum 130.

The cabinet 110 forms an appearance and is implemented in a substantially rectangular parallelepiped shape.

A receiving space is formed in the cabinet 110, and an opening 115 is provided on the front surface of the cabinet 110 to allow laundry to enter and exit the cabinet 110.

The cabinet 110 may be provided with a door 117 for opening and closing the opening 115.

A tub 120 may be provided in the cabinet 110.

The tub 120 may be configured to receive water therein.

The tub 120 may have a cylindrical shape opened frontward.

The tub 120 can be buffered and supported by a suspension device having a plurality of springs 122 and dampers 124, for example.

The drum 130 may be rotatably received in the tub 120.

The drum 130 may be formed in a cylindrical shape that opens forward.

The drum 130 may have a plurality of through-holes 132 so that the inside and outside of the drum 130 can communicate with each other.

The drum 130 may include a plurality of lifters 134 to move the laundry upward when the drum 130 rotates.

Meanwhile, the drum 130 may include a rotation shaft 135 protruding from a rear end thereof.

The rotation shaft 135 may protrude rearward through the tub 120.

The tub 120 may be provided with a rotary shaft support 125 for rotatably supporting the rotary shaft 135.

The rotary shaft support 125 includes, for example, a housing 126; And a plurality of bearings 127 provided in the housing 126.

A motor 150 having a variable magnet according to an embodiment of the present invention may be provided at the rear end of the tub 120.

2 to 4, a motor 150 having a variable magnet according to an embodiment of the present invention includes a stator 160 having a stator coil 171; And a rotor (210) rotatably spaced apart from the stator (160) by an air gap, the rotor (210) comprising: a rotor core (211); A stationary magnet (241) disposed radially to the rotor core (211) and spaced apart in the circumferential direction; And a variable magnet 251 having a coercive force smaller than that of the fixed magnet 241 and arranged in the circumferential direction of the rotor core 211 so as to be closer to the gap than the fixed magnet 241 The variable magnet 251 may be configured such that the magnetic force is varied by a magnetic force generated by the stator coil 171 when a preset current is applied to the stator coil 171. [

The stator 160 may be configured to include a stator core 161 and a stator coil 171 wound around the stator core 161, for example.

The stator core 161 may be configured to include a yoke portion 162 and a plurality of teeth 164 projecting from the yoke portion 162, for example.

A slot 166 may be provided between the plurality of teeth 164.

The stator 160 may be configured to include, for example, 36 slots 166.

The stator core 161 may be formed of a spiral core, for example, in which the yoke portion 162 has a long strip shape and is stacked in a circular shape.

The plurality of teeth 164 may be arranged to protrude to the outside of the yoke portion 162, for example.

The stator 160 may include an insulator 181 for insulating the stator core 161 and the stator coil 171.

The insulator 181 may include an upper insulator 182 and a lower insulator 183 which are coupled to each other at the upper side and the lower side along the stacking direction of the stator core 161, for example.

The insulator 181 may have a plurality of coupling bosses 185 for coupling with the tub 120.

The plurality of coupling bosses 185 may be formed with fastening member insertion holes 186 through which the fastening members 187 can be inserted.

Meanwhile, the rotor 210 may be rotatably disposed with a predetermined gap on the outside of the stator 160, for example.

The rotor 210 includes, for example, a rotor core 211; A stationary magnet (241) disposed along the radial direction of the rotor core (211) and spaced apart in the circumferential direction; And a variable magnet (251) having a coercive force smaller than that of the fixed magnet (241) and arranged along the circumferential direction of the rotor core (211) so as to be closer to the gap than the fixed magnet Lt; / RTI >

The rotor 210 may be configured to have, for example, 48 poles.

The fixed magnet 241 and the variable magnet 251 may be constituted by 48 pieces.

The rotor core 211 may include a plurality of divided cores 220 spaced apart from each other along a circumferential direction, for example.

As shown in FIG. 5, the rotor 210 may have a molding part 261 formed by molding to surround the outer surfaces of the plurality of divided cores 220.

The molding part 261 may be formed of, for example, an electrically insulating member.

The molding part 261 may be formed to have a predetermined thickness on the inner side and the outer side along the radial direction of the plurality of divided cores 220, for example.

Accordingly, the divided core 220, the fixed magnet 241, and the variable magnet 251, which are spaced from each other in the circumferential direction, can be integrally fixed and supported.

The rotor 210 may include a rotor frame 271 connected to the rotation shaft 135.

The rotor frame 271 may have a cylindrical shape with one side opened.

The molding part 261 may be received in the rotor frame 271.

The rotor frame 271 may include, for example, a cylindrical rotor frame body 272 and a support portion 277 for supporting the molding portion 261.

The supporting portion 277 includes an outer circumferential surface support portion 278 for supporting the outer circumferential surface of the molding portion 261 in contact with one side And a bottom support portion 279 which is supported.

For example, the bottom support portion 279 may be formed so as to extend along the circumferential direction while being reduced along the radial direction with respect to the outer circumferential surface support portion 278.

The rotor frame 271 may be formed at the center thereof with a rotation shaft connection part 274 through which the rotation shaft 135 is connected.

A plurality of blades 276 protruding in the axial direction and spaced apart from each other along the circumferential direction may be provided around the rotation shaft connecting portion 274.

According to such a configuration, the movement of air can be promoted by the plurality of blades 276 when the rotor 210 rotates.

6, the stationary magnet 241 may have a rectangular cross-sectional shape having a predetermined width W1 and a thickness t1, for example.

The variable magnet 251 may be configured to have a rectangular cross-sectional shape having a predetermined width w2 and a thickness t2, for example, as shown in Fig.

The variable magnet 251 may be configured to have a thickness t2 that is smaller than the thickness t1 of the fixed magnet 241, for example.

More specifically, for example, the variable magnet 251 may be configured to have a thickness t2 of 19.5 to 28.5% of the thickness t1 of the fixed magnet 241.

For example, the variable magnet 251 may have a thickness t2 of 1.6 to 2 mm, and the fixed magnet 241 may have a thickness t1 of 7 to 8.2 mm.

The variable magnet 251 may be configured to have a width w2 that is smaller than the width w1 of the fixed magnet 241, for example.

More specifically, for example, the width w2 of the variable magnet 251 may be configured to be 77.3 to 83.6% of the width w1 of the fixed magnet 241.

For example, the variable magnet 251 may have a width w2 of 11.6 to 12.2 mm, and the fixed magnet 241 may have a width w1 of 14.6 to 15.0 mm.

The variable magnet 251 may be configured to have a lower coercive force than the coercive force of the fixed magnet 241, for example.

More specifically, the variable magnet 251 and the fixed magnet 241 are each formed of a ferrite magnet, and the variable magnet 251 may be configured to have a lower coercive force than the coercive force of the fixed magnet 241 .

In this embodiment, the variable magnet 251 and the fixed magnet 241 are each formed of a ferrite magnet, but this is merely an example, and may be formed of another permanent magnet material.

The stationary magnets 241 may be configured such that different magnetic poles (N poles, S poles) are alternately arranged along the circumferential direction.

The variable magnets 251 may be configured such that different magnetic poles (N poles, S poles) are alternately arranged along the circumferential direction.

The variable magnet 251 may be configured to have the same magnetic pole as the fixed magnet 241 disposed on one side (left side along the clockwise direction in the figure), for example, as shown in Fig.

Accordingly, the direction of the magnetic flux generated by the variable magnet 251 can be aligned with the direction of the fixed magnet 241.

8, the plurality of divided cores 220 includes a divided core body 222 having a substantially rectangular cross-sectional shape, and a plurality of divided core bodies 222, which are fixed to both sides of the divided core body 222, A fixed magnet support portion 224 formed to support the magnet 241 and a variable magnet support portion 234 formed on one side of the divided core body 222 to support the variable magnet 251 Respectively.

The plurality of divided cores 220 may be formed by inserting and stacking a plurality of electric steel plates including the divided core body 222, the fixed magnet supporting portion 224 and the variable magnet supporting portion 234, .

The divided core body 222 may have, for example, a substantially rectangular shape.

More specifically, for example, the divided core body 222 may have a rectangular (trapezoid) shape in which the width of the outer side portion along the radial direction is slightly larger than the width of the inner side portion.

Side supporting portions 228 for supporting one side of the fixed magnet 241 may be formed on both side surfaces of the divided core body 222, respectively.

The side support portions 228 on both sides of the divided core body 222 may be formed to be in surface contact with the fixed magnet 241, for example.

The divided core bodies 222 may be spaced apart from each other at predetermined intervals along the circumferential direction.

The divided core bodies 222 may be spaced from each other along the circumferential direction corresponding to the thickness t1 of the fixed magnet 241, for example.

The stationary magnet support portion 224 includes a stationary magnet support rib 225 protruding from the divided core body 222 in the radial direction and bent along the circumferential direction to surround the edge of the stationary magnet 241 Lt; / RTI >

The variable magnet support portion 234 is formed by projecting along the circumferential direction from the gap side edge of the divided core body 222 and being bent toward the gap side along the radial direction to cover the variable magnet support portion 234, And a magnet supporting rib 235 as shown in FIG.

 The fixed magnet supporting ribs 225 may be respectively provided on both side edges of the outer end along the radial direction of the divided core body 222.

The fixed magnet supporting ribs 225 may protrude outward from the divided core body 222 and may be formed to be bent along the circumferential direction.

Accordingly, the outer end of the divided core body 222 and the outer end of the fixed magnet 241 may be disposed at substantially the same distance from the center of rotation of the rotor 210.

According to such a configuration, the permanent magnet supporting ribs 225 substantially increase the magnetoresistance, so that the magnetic flux does not flow or flows very little, so that generation of the potato in the corner area of the stationary magnet 241 can be suppressed.

The stationary magnet supporting rib 225 may include a protruding section 226 protruding to the outside of the divided core body 222 and a bent section 227 bent in the circumferential direction from the protruding section 226 As shown in FIG.

The variable magnet supporting ribs 235 may be provided on both side edges of the inner end along the radial direction of the divided core body 222.

A side support portion 238 for supporting one side portion of the variable magnet 251 may be formed at an inner end portion along the radial direction of the divided core body 222.

The side support portion 238 of the divided core body 222 may be formed to be in surface contact with one side surface of the variable magnet 252.

The variable magnet supporting ribs 235 may be respectively formed, for example, in the circumferential direction at the corners of the inner end of the divided core body 222 and bent back to the air gap side along the radial direction.

The variable magnet supporting rib 235 includes a protruding section 236 protruding along the circumferential direction of the divided core body 222 and a bent section 237 bent in the radial direction from the protruding section 236, As shown in FIG.

The protruding section 236 of the variable magnet supporting rib 235 is formed to have an interval L1 corresponding to the width w1 of the bending section 227 of the fixed magnet supporting rib 225 and the fixed magnet 241 And can be configured to be spaced apart from each other.

The outer edge of one side portion of the fixed magnet 241 is supported by the bending section 227 of the fixed magnet supporting rib 225 and the inner edge is supported by the protruding section 236 of the variable magnet supporting rib 235 Respectively.

The variable magnet supporting ribs 235 formed at the inner corners of the divided core body 222 may have a length L2 corresponding to the width w2 of the variable magnets 251. [

Thus, both ends of the variable magnet 251 can be respectively supported in the circumferential direction.

The variable magnet supporting ribs 235 are disposed on both sides of the variable magnets 251 to form a path of a main flux and a magnetic path of the variable magnets 251 The generation of potatoes in both end regions can be suppressed.

Meanwhile, as shown in FIG. 9, the garment processing apparatus of the present embodiment may include a control unit 290 implemented by a microprocessor having a control program.

The control unit 290 may be connected to the operation mode selection unit 295 so that the operation mode can be selected.

The operation mode can be configured to appropriately select the time and / or the number of times of, for example, the washing, rinsing, dewatering and drying steps.

The controller (290) can controllably connect the motor (150) to control the rotation of the drum (130) based on the operation mode selected by the operation mode selector (295).

The control unit 290 controls the stator coil 171 such that the predetermined current is applied to the stator coil 171 so that the variable magnet 251 can be boosted before the rotor 210 is operated at the preset first speed Can be configured to be controlled.

Here, the first speed may be set to, for example, a speed substantially equal to the rotational speed of the drum 130 during rinsing.

The controller 290 controls the stator coil 171 in advance so that the variable magnet 251 can be demagnetized before the rotor 210 is operated at a second speed that is faster than the first speed And can be configured to be controlled so that the set current is applied.

Here, the second speed may be set, for example, at a speed substantially equal to the rotational speed at the time of dewatering the drum 130.

The control unit 290 can control the motor 150 such that the variable magnets 251 can be boosted before starting the washing cycle of the drum 130 to enable a low speed high torque operation.

More specifically, for example, as shown in Fig. 10, the stationary magnet 241 and the variable magnet 251 are arranged such that, when the center of the variable magnet 251 in the center of the three continuously variable magnets 251 is increased, A fixed magnet 241 provided on both sides of the variable magnet 251 on both sides of the central variable magnet 251 and the central variable magnet 251 and the direction of the magnetic force lines of the stator coil 171, The directions of the lines of magnetic force of the magnetic field lines of the magnetic field lines can be aligned with each other.

Thereby, the variable magnet 251 can be increased more effectively.

11, the magnetic force (magnetization vector) of the variable magnet 251 can be easily recovered by the magnetic line of force of the fixed magnet 241 even if the variable magnet 251 is largely demagnetized have.

With this configuration, the plurality of divided cores 220 can be spaced apart from each other at predetermined intervals along the circumferential direction.

The fixed magnet 241 may be inserted into the fixed magnet support portion 224 and the variable magnet 251 may be inserted into the variable magnet support portion 234, respectively.

A liquid molding material made of an electric insulating member may be filled in the inside and the outside of the plurality of divided cores 220 and cured to form the molding part 261.

Accordingly, the split core 220, the fixed magnet 241, and the variable magnet 251 can be integrally fixedly coupled.

The split core 220, the fixed magnet 241, and the variable magnet assembly may be inserted into the rotor frame 271.

The stator 160 is coupled to the rear end of the tub 120 and the rotating shaft 135 passing through the stator 160 may be connected to the rotating shaft connecting portion 274 of the rotor frame 271.

Meanwhile, the control unit 290 may control the motor 150 to increase the variable magnet 251 before the start of the washing cycle.

More specifically, the controller 290 controls the motor 150 so that a d-axis current (boosting current) to which the variable magnet 251 can be supplied is energized to the stator coil 171 of the motor 150, Can be controlled.

As a result, the magnetic force of the variable magnet 251 is increased, and the torque of the rotor 210 is increased, so that a low-speed, high-torque operation can be performed.

Meanwhile, the control unit 290 may control the motor 150 so that the variable magnet 251 is magnetized before the start of the dewatering stroke.

More specifically, the control unit 290 controls the motor 150 so that a d-axis current (potato current) that can be excited by the variable magnet 251 is energized in the stator coil 171 of the motor 150, Can be controlled.

Accordingly, the magnetic force of each variable magnetic force is reduced and the torque of the rotor 210 is reduced, so that high-speed low-torque operation can be performed.

In this embodiment, the control unit is embodied as a control unit of the clothes processing apparatus, but the motor may be configured to include the control unit.

The foregoing has been shown and described with respect to specific embodiments of the invention. However, the present invention may be embodied in various forms without departing from the spirit or essential characteristics thereof, so that the above-described embodiments should not be limited by the details of the detailed description.

Further, even when the embodiments not listed in the detailed description have been described, it should be interpreted broadly within the scope of the technical idea defined in the appended claims. It is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

110: cabinet 117: door
120: tub 125:
130: Drum 132: Through hole
134: lifter 135:
150: motor 160: stator
161: stator core 162: yoke portion
164: Teeth 166: Slot
181: insulator 182: upper insulator
183: Lower insulator 210: Rotor
211: rotor core 220: split core
222: split core body 224: fixed magnet support
225: fixed magnet supporting ribs 226, 236: protruding section
227, 237: Bending section 228, 238:
234: variable magnet supporting portion 235: variable magnet supporting rib
241: stationary magnet 251: variable magnet
261: molding part 271: rotor frame
274: rotation shaft connecting portion 290:
295: Operation mode selection unit

Claims (12)

A stator having a stator coil; And
And a rotor rotatably and spaced apart from the stator with an air gap therebetween,
The rotor may include:
Rotor core;
A stationary magnet disposed along the radial direction of the rotor core and spaced apart in the circumferential direction; And
And a variable magnet having a coercive force smaller than that of the fixed magnet and disposed along the circumferential direction of the rotor core so as to be closer to the gap than the fixed magnet,
Wherein the variable magnet has a magnetic force which is varied by a magnetic force generated by the stator coil when a preset current is applied to the stator coil. The method according to claim 1,
Wherein the stationary magnet and the variable magnet are alternately disposed with mutually different magnetic poles along the circumferential direction,
Wherein the fixed magnet and the variable magnet are arranged in such a manner that a direction of a magnetic force line of the stator coil and a direction of a variable magnet on both sides of the central variable magnet and a center of the variable magnet And the magnetic force lines of the stationary magnets provided on both sides are arranged so as to coincide with each other. The method according to claim 1,
Wherein the rotor core includes a plurality of divided cores spaced apart at predetermined intervals along a circumferential direction. The method of claim 3,
The plurality of divided cores may include: a divided core body; And a stationary magnet support unit configured to support the stationary magnets on both sides of the divided core body along the circumferential direction, respectively. 5. The method of claim 4,
Wherein the fixed magnet supporting portion comprises a fixed magnet supporting rib which protrudes along the radial direction from the divided core body and is bent along the circumferential direction to surround the edge of the fixed magnet. The method of claim 3,
The plurality of divided cores may include: a divided core body; And a variable magnet support portion formed to support the variable magnet in an area close to the gap of the divided core body. The method according to claim 6,
Wherein the variable magnet support portion includes a variable magnet portion that protrudes from both side edges close to the gap in the corners of the divided core body respectively in the circumferential direction and is bent toward the gap along the radial direction to surround both ends of the variable magnet, And a support rib (22). The method of claim 3,
Wherein the rotor further comprises a molding part formed by molding to surround an outer surface of the plurality of divided cores. The method according to claim 1,
Wherein the variable magnet is thinner than the fixed magnet. 10. The method according to any one of claims 1 to 9,
Wherein the variable magnet is energized by the stator coil before the rotor is rotated at a preset first speed. 11. The method of claim 10,
Wherein the variable magnet is demagnetized by the stator coil before the rotor is rotated at a second speed higher than the first speed. cabinet;
A drum rotatably installed in the cabinet; And
And a motor having the variable magnet according to claim 1 for rotating the drum.

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