JP2002262494A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the weak field system of the magnetic flux of a permanent magnet. SOLUTION: The rotor of a permanent magnet rotary electric machine is divided to enable relative motion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor using a permanent magnet as a magnetic field, and more particularly to an electric motor for driving a washing machine and a control method thereof, wherein the rotor of the electric motor has a first field magnet and a second field magnet. An electric motor comprising magnetic magnets, which changes the center positions of the magnetic poles of the first field magnet and the second field magnet in accordance with the torque direction, and which can change the effective magnetic flux amount in accordance with the number of revolutions. It relates to a control method.

[0002]

2. Description of the Related Art In a conventional permanent magnet field type motor, an induced electromotive force E is determined by a constant magnetic flux .PHI. Generated by a permanent magnet disposed on a rotor and a rotational angular speed .omega. Of the motor. That is, as the rotational angular speed ω (rotational speed) of the motor increases, the induced electromotive force of the motor increases in proportion.

[0003] Although high torque can be obtained in a low-speed region, operation in a high-speed region is difficult due to a narrow variable range of the rotation speed. Therefore, it is conceivable to widen the high-speed operation range by the field weakening control technology.

Further, in order to secure a predetermined output in a wide speed range, a motor of a washing machine transmits torque through a belt and a gear via a pulley. However, recently, there is a direct drive system for directly transmitting the torque of an electric motor to a rotating body such as a pulsator or a dewatering tank.

[0005]

SUMMARY OF THE INVENTION In the prior art of a washing machine,
When the torque of the electric motor is transmitted by the belt and the gear via the pulley, there is a problem that the noise such as the sliding of the belt and the gear and the impact sound is large.

In a direct drive system for directly transmitting the torque of an electric motor to a rotating body (for example, a pulsator) or a dehydration tub, expanding the high-speed operation region by the above-described field weakening control technique requires heat generation by field weakening current. There is a limit due to such factors as reduced efficiency. Since the direct drive system does not have a speed reduction mechanism, the size of an electric motor which covers a wide range of speeds in a low-speed high-torque washing and rinsing process and a high-speed large-power dehydration process becomes large.

[0007]

According to the present invention, a washing and dewatering tub rotatably supported on a rotating shaft in an outer tub and a rotating shaft concentric with the rotating shaft are provided at the bottom of the washing and dewatering tub. A rotating body rotatably supported at the center (for example, a pulsator)
And a switching mechanism for connecting or disconnecting the rotating shaft of the washing and dewatering tub to and from the rotating shaft of the rotating body, and an electric motor, and washing by rotating the rotating body that stirs the inside of the washing tub forward and reverse. Alternatively, in a washing machine that performs a rinsing process and finally performs a dehydration process, the electric motor includes a stator having a primary winding and a rotor having a field magnet, and the field magnets are sequentially different in a rotating direction. A first field magnet in which magnetic poles of different polarities are arranged and a second field in which magnetic poles of different polarities are sequentially arranged in the direction of rotation capable of rotating relative to the first field magnet. And the first and second field magnets are opposed to the stator magnetic poles, and the phase of the combined magnetic pole of the first and second field magnets is set to the first field magnet. Mechanism that changes the magnetic pole of the field magnet according to the torque direction of the rotor A mechanism for changing with the torque direction, the torque direction and the first and second generated in the rotor
The first field is balanced by the magnetic force between the field magnets.
And means for aligning the same magnetic pole centers of the first and second field magnets, and means for shifting the magnetic pole centers of the first and second field magnets as the direction of torque generated in the rotor is reversed. Use an electric motor.

[0008]

Embodiments of the present invention will be described below.

FIG. 1 schematically shows a washing machine in which a permanent magnet type synchronous motor of this embodiment is arranged.

Reference numeral 2 denotes an electric motor, which employs a permanent magnet field synchronous motor that directly drives the pulsator 73 to rotate (direct drive). The electric motor 2 rotates the pulsator 73 and the dewatering tub 72 via a clutch.

In a washing machine case 70 shown in FIG. 1, there are an outer tub 71 and a washing and dewatering tub 72. The rotating shaft 22 in the outer tank 71
A washing and dewatering tub 72 rotatably supported on the center thereof; a pulsator 73 rotatably supported on the bottom of the washing and dewatering tub about a rotating shaft concentric with the rotating shaft; and a rotating shaft of the pulsator. And a switching mechanism 77 for connecting or disconnecting the rotating shaft of the washing and dewatering tub, and the electric motor 2. The pulsator for stirring the inside of the washing tub is subjected to a forward / reverse operation to perform a washing or rinsing process. Is a washing machine that performs a dehydration process. Washing machines include a type in which water is stored only in the dewatering tub and a type in which water is stored in the entire water tub 71 including the dewatering tub during rinsing. The present invention can be applied to any type.

The washing machine having such a configuration is driven by an inverter 78. The inverter is assumed to be controlled by a microcomputer, and the rotation speed of the electric motor 2 is varied by receiving a command from the microcomputer. This is a motor control circuit as control means, and a microcomputer control circuit is built in the inverter. The inverter 78 also has a function as a motor current detecting means for detecting a value of a current flowing through the electric motor 2. In addition, as basic components of the washing machine, there are a drain valve 74, an operation panel 75, a water level sensor 7 and the like.
6 and so on.

FIG. 2 schematically shows a case where the center of the same magnetic pole of the rotor of the electric motor 2 shown in FIG. 1 is shifted.

In FIG. 2, an armature winding 11 is wound around a stator core 10 in a slot, and is connected to a housing 13 having a cooling passage 12 through which a refrigerant flows.

The permanent magnet embedded rotor 20 includes a first rotor 20A fixed to a shaft 22 and a second rotor 20B separated from the shaft 22. Of course, not only a permanent magnet embedded type rotor but also a surface magnet type rotor may be used.

In the first rotor 20A, permanent magnets 21A are arranged with magnetic poles having different polarities sequentially in the rotation direction. Similarly, in the second rotor 20B, permanent magnets 21B are sequentially arranged with magnetic poles having different polarities in the rotation direction. The field magnet in which the two rotors of the first and second rotors are arranged on the same axis faces the stator magnetic poles.

The inner side of the second rotor 20B is a nut 23
B, and the corresponding shaft has a thread 2
3A, when they are connected to each other with a screw function, the second rotor 20B can be axially changed while rotating with respect to the shaft.

Further, the second rotor 20B is prevented from protruding from the center of the stator by more than a predetermined displacement.
A stopper 24 is provided at a position distant from the side surface of OB. Further, if a stopper driving actuator 25 which is a servo mechanism is provided so that the stopper 24 can be changed to the left and right in parallel with the shaft, the deviation of the center of the magnetic pole between the first field magnet and the second field magnet can be reduced. Can be changed. As a result, it is possible to control the entire effective magnetic flux amount including the first field magnet and the second field magnet for the stator in which the armature winding 11 is wound in the slot. .

A description will be given of how the effective magnetic flux of the permanent magnet is changed according to the direction of the torque by the above operation.

Basically, in a motor using an armature winding for a stator and a permanent magnet for a rotor, if the rotation direction of the rotor when operating as a motor is the same as that when operating as a generator, the motor The direction of torque received by the rotor when acting as a generator and when acting as a generator is opposite.

When working with the same electric motor, if the rotation direction of the rotor is reversed, the torque direction is also reversed. Similarly, when working with the same generator, if the direction of rotation of the rotor is reversed, the direction of torque will also be reversed.

The basic theory based on the rotation direction and the torque direction described above is applied to the motor according to the embodiment of the present invention as follows.

When operating in the low speed range, such as during the required washing or rinsing stroke, large torque
As shown in FIG. 3, the center of the same magnetic pole of the first rotor 20A and the second rotor 20B is forcibly aligned to increase the effective magnetic flux amount by the permanent magnet facing the stator magnetic pole,
High torque characteristics can be obtained.

Next, when operating in a high-speed rotation region such as a dehydration process, as shown in FIG. 4, the second rotor 20B moves the first rotor 20B to the shaft 22 such that the nut is removed from the thread of the bolt. If the center of the same magnetic pole is rotated while the interval between the rotor 20A and the second rotor 20B is widened while being widened, the amount of effective magnetic flux by the permanent magnet facing the stator magnetic pole is reduced. In other words, There is a field weakening effect, and high output characteristics can be obtained in a high rotation region.

FIG. 4 schematically shows a state in which the center of the same magnetic pole is shifted while the distance between the first rotor 20A and the second rotor 20B is widened and the effective magnetic flux by the permanent magnet facing the stator magnetic pole is small. Show.

FIGS. 3 and 4 illustrate the bolt head 61, the bolt screw portion 60 and the nut portion 62, and the bolt head 61 includes the first rotor 20A and the nut portion. 6
Reference numeral 2 corresponds to the second rotor 20B. Assuming that the screw portion 60 of the bolt (corresponding to 23A in FIG. 2) rotates in the same direction, the nut portion 62 is tightened or released depending on the direction of the torque applied to the nut portion 62. 20B performs the same function depending on the torque direction of the rotor.

When the motor rotates as a motor, the direction of torque is reversed during forward rotation and reverse rotation, and the state shown in FIG. 3 during forward rotation is the state shown in FIG. 4 during reverse rotation.

Of course, the inner diameter side of the second rotor 20B is a nut portion 23B, and the shaft corresponding to the nut portion is a bolt screw portion 23A, which is connected to each other with a screw function. If this is done (for example, from a right-handed screw to a left-handed screw), the states shown in FIGS. 3 and 4 are reversed.

For example, as shown in FIG. 3, the first rotor 20A is forcibly applied even in the forward / reverse operation in the washing or rinsing process.
And a screw in which the center of the same magnetic pole of the second rotor 20B is aligned, the amount of effective magnetic flux by the permanent magnet facing the stator magnetic pole is increased, and high torque characteristics can be obtained.

Next, when operating in a high-speed rotation region such as a dehydration process, as shown in FIG. 4, the second rotor 20B is moved relative to the shaft 22 so that the nut portion is removed from the screw portion of the bolt. If the center of the same magnetic pole is rotated while the interval between the rotor 20A and the second rotor 20B is widened while being widened, the amount of effective magnetic flux by the permanent magnet facing the stator magnetic pole is reduced. In other words, There is a field weakening effect, and a constant output characteristic is obtained in a high rotation region.

The operation of the induced electromotive force by the motor of the present invention will be described.

FIG. 5 shows the characteristics of the effective magnetic flux, induced electromotive force, and terminal voltage with respect to the rotational angular velocity of the permanent magnet type synchronous motor.

The induced electromotive force E of the permanent magnet type synchronous motor is determined by the constant magnetic flux Φ generated by the permanent magnet disposed on the rotor and the rotational angular speed ω of the motor. That is, FIG.
As shown in (a), if the constant magnetic flux Φ1 generated by the permanent magnet disposed on the rotor is constant, when the rotational angular velocity ω (rotation speed) increases, the induced electromotive force E1 of the motor increases proportionally. I do. However, the output voltage of the inverter is limited due to the terminal voltage of the power supply and the capacity of the inverter, and the induced electromotive force generated by the motor in the steady operation state is also limited. Therefore, in the permanent magnet type synchronous motor, so-called field-weakening control must be performed in order to reduce the magnetic flux generated by the permanent magnet in a region where the rotation speed is equal to or higher than a certain value.

Since the induced electromotive force increases in proportion to the rotational angular velocity, the current of the field weakening control must be increased. Therefore, it is necessary to supply a large current to the coil as the primary conductor, and the heat generated by the coil naturally occurs. Increase. For this reason, there is a possibility that the efficiency of the electric motor in the high rotation region is reduced, and the permanent magnet is demagnetized due to heat generation exceeding the cooling capacity.

For example, as shown in FIG. 5 (a), when a magnetic flux Φ1 generated by a permanent magnet disposed in a rotor is changed to a magnetic flux Φ2 at a certain rotational angular velocity ω1 (rotation speed), the induction of the motor is started. The maximum value of the induced electromotive force can be limited by changing from the electromotive force E1 to the induced electromotive force E2 characteristic.

FIG. 5B schematically shows that the induced electromotive force E can be kept constant if the magnetic flux Φ changes more finely according to the rotational angular velocity ω (rotation speed).

As one embodiment of the means for obtaining the characteristics shown in FIG. 5, the first field magnet is fixed to a shaft, the second field magnet is separated from the shaft, and the shaft is A nut portion is formed inside the screw portion of the bolt and the inside of the second field magnet so as to have a screw function with each other.
It is possible to use an electric motor provided with a stopper provided at a position distant from the side surface of the field magnet, and having a servo mechanism capable of changing the stopper in parallel with the shaft according to the rotation speed.

FIG. 6 is a control block diagram of the electric motor 2 shown in FIG.

First, based on the information set from the operation panel (75 in FIG. 1), the information from the water level sensor 76, and the rotation speed of the permanent magnet type synchronous motor 2, the operation judgment unit 101 makes the permanent magnet type synchronous It determines the operation of the electric motor 2 and outputs a current command value. The current command value output from the operation determination unit 101 is input to a current control block 102 that performs non-interference control and the like on the difference between the current value of the permanent magnet type synchronous motor 2 and the current value.

The output from the current control block 102 is converted into a three-phase alternating current by a rotary coordinate conversion unit 103, and controls the permanent magnet synchronous motor 2 via an inverter 104. Further, the current (at least two-phase current) and the rotation speed of each phase of the permanent magnet type synchronous motor 2 are detected, and the current of each phase is converted into a two-axis current by a two-axis conversion block 105, and converted into a current command value. We have feedback. The rotation speed and the magnetic pole position are detected by the detector 106 and fed back to each control block through the magnetic pole position conversion unit 107 and the speed conversion unit 108.

In the embodiment shown in FIG. 6, the case where the position / speed sensor of the electric motor 2 and the electric current sensor of the electric motor are provided is shown. However, some of these sensors are eliminated, and the electric motor 2 is sensorless. A drive type control configuration can be similarly implemented.

Further, the permanent magnet type synchronous motor of the present invention
Since the centers of the same magnetic poles of the first rotor and the second rotor are aligned or deviated depending on the operating condition,
It has a function of correcting the advance of the current supply by the controller that controls the inverter according to the displacement of the composite magnetic pole position between the field magnet and the second field magnet.

An embodiment for correcting the advance angle of the current supply will be described.

The first field magnet is fixed to a shaft,
When the second field magnet is separated from the shaft and the shaft is operated with a screw portion of a bolt and a nut portion inside the second field magnet and having a screw function with each other, the shaft is operated. The second field magnet moves left and right in the axial direction while rotating.

FIG. 12 shows the relationship between the rotation angle and the axial displacement when the centers of the same magnetic poles of the first rotor and the second rotor are aligned or deviated according to the operating conditions.

In FIG. 12, the rotation angle θ of the second rotor and the axial displacement ΔL are in a proportional relationship, and the axial displacement ΔL is measured using the displacement measuring device 64, and the position detecting circuit ( The value fed back to 106) in FIG. 6 is used as the value converted into the deviation angle of the composite magnetic pole position between the first field magnet and the second field magnet for the optimal control for correcting the advance of the current supply.

FIG. 7 shows an electric motor according to another embodiment of the present invention.

The first rotor 20A is fixed to the shaft 22, the second rotor 20B is separated from the shaft 22, and a part of the shaft is provided with a screw portion 23A of a bolt and the inside of the second field magnet. If the sleeve 41 is fixed to the shaft 41 and the nut 41B is fixed to the inside of the sleeve 41, the second rotor 20B with respect to the shaft 22 is moved so that the nut is removed from the threaded portion of the bolt. Rotor 2
The rotor rotates while the interval between 0A and the second rotor 20B increases.

Since there is a slight play between the inside of the second field magnet and the shaft 22, if a change in the flux linkage between the inside of the second field magnet and the shaft 22 occurs with rotation, Although there is an obstacle such as eclipse, the sleeve 11 is made of a non-magnetic material having a higher electric resistivity than iron, so that the shaft 22 is magnetically and electrically connected between the inside of the second field magnet and the shaft 22. Also has the effect of insulating.

Support mechanisms 40A and 40B are provided inside the sleeve 41 between the second field magnet and the shaft so as to be able to guide rotation, reciprocation and composite movement.

The second rotor 20B is connected to a part of the shaft so as to have a screw function mutually with the screw portion 23A of the bolt, and a variable stopper is provided at a position apart from the side surface of the second field magnet. 24 are provided. Support mechanisms 42 and 47 are provided between the stopper 24 and the shaft, and between the stopper and the side surface of the second rotor 20B so as to guide rotation, reciprocation and combined movement. The support mechanism 42 has a function of a thrust bearing, and the support mechanism 47 has a function of guiding a rotational motion, a reciprocating motion, and a composite motion while being a radial bearing.

Further, the provision of the spring 48 has the effect of improving the function of the support mechanism 42 as a thrust bearing.

An electromagnetic clutch will be described as an example of a servo mechanism in which the stopper 24 can be changed in parallel with the shaft.

The configuration of the electromagnetic clutch may be such that the coil 46 is wound around the yoke 44 and the stopper 24 also has the function of the movable iron core. The yoke 44 and the coil 46 are fixed to a frame 49 of the electric motor or a part of the washing machine (not shown).
5 has a function of a return device at the time of excitation interruption. A bearing 50 is supported between the motor frame 49 and the shaft 22.

FIG. 7 is a schematic diagram showing a state where the coil 46 is not excited, and FIG. 8 is a schematic diagram showing a state where the coil 46 is excited.

When the coil 46 is excited, the yoke 44 becomes a strong electromagnet and attracts the stopper 24 which also serves as a movable iron core.

When exciting the coil 46 and sucking the stopper 24, the second rotor 20B
If a torque is applied so that the gap between the first rotor 20A and the second rotor 20B is widened so that the nut part is disengaged from the thread part of the bolt, the load of the current flowing through the coil 46 is reduced. I'm done.

The electromagnetic clutch shown here has a stopper 2
4 is an example of a servo mechanism capable of changing the position of the stopper 4 in parallel with the shaft. A finer stopper can be positioned by using a hydraulic actuator, a linear driving device including a rotating machine and a ball screw, a linear motor, and the like.

FIG. 9 shows an example of the sleeve 41 fixed inside the second rotor 20B.

As one of the fixing methods, the two parts consisting of the second rotor 20B and the sleeve 41 are fixed to each other by making the surfaces thereof contact each other with unevenness. Also, the shaft 22
The outline of the difference between the inside of the first rotor 20A and the inside of the second rotor 20B separated from the shaft 22 is shown.

FIG. 10 shows another embodiment of the present invention.

A recess 53 is provided on the side surface of the first field magnet where the first field magnet and the second field magnet are in contact, and the second field magnet also has the function of the sleeve. This is a structure in which a projection 54 is provided. The protrusion 54 is the sleeve 41
May be integrated with the second rotor 20B. Therefore, a sufficient space for the sleeve 41 can be secured, and the spring 48, the support mechanisms 40A and 40B, the nut 2
By effectively arranging the 3Bs and the like, this is one of the effective methods for a motor having a small axial length product thickness of the second rotor 20B.

FIG. 11 shows another embodiment of the present invention.

The basic components shown in FIG. 11 are the same as those shown in FIG. 7, except that a part corresponding to the electromagnetic clutch is changed. FIG. 11 shows a state in which the coil 46 is excited, and when the excitation is cut off, the yoke 44 and the stopper 24 are separated by the spring 45. Further, the second rotor 20B has a characteristic that a thrust can be obtained by the function of the screw due to the interaction between the screw portion 23A and the nut portion 23B of the bolt that applies a torque to the second rotor 20B. Therefore, if a thrust for pushing the stopper 24 is applied due to the mutual relationship between the screw and the torque, the excitation of the coil 46 is cut off and the stopper 24 is separated from the yoke 44. The yoke 44 is the arm 5
It is fixed to the frame 49 or a part of the main shaft (not shown) via the two.

The electromagnetic clutch shown in FIG.
Is an example of a servo mechanism capable of changing the stopper 24 in parallel with the shaft as in the description of
The use of a rotating machine and a linear drive device such as a ball screw, a linear motor, or the like allows finer positioning of the stopper 24.

FIG. 13 shows another embodiment of the present invention.

As a feature of the electric motor of the present invention, the first rotor 20A is firmly fixed to the shaft 22, while the second rotor 20B has a degree of freedom with respect to the shaft 22. . Therefore, there is a slight mechanical dimension play between the second rotor 20B and the shaft 22, and eccentricity may occur when a large torque or centrifugal force is applied. Therefore, the air gap Gap2 between the second rotor 20B having the second field magnet and the stator is larger than the air gap Gap1 between the first rotor 20A having the first field magnet and the stator. Enlarging the size has the effect of eliminating mechanical connection between the second rotor 20B and the stator due to eccentricity.

Between the stopper 24 and the second rotor 20B,
By providing a plurality of springs 48 and springs 51 between the first rotor 20A and the second rotor 20B, the second rotor 20A is provided.
This has the effect of suppressing the rapid fluctuation of B and assisting the movement in the torque direction.

Of course, the components shown in the figures can be combined in various ways, and it goes without saying that they can be added or removed according to the application.

FIG. 14 shows a rotating electric machine according to another embodiment of the present invention.

The screw portion 23 of the second rotor shown in FIG.
The permanent magnet type synchronous rotating electric machine is characterized in that a mechanism capable of varying the rotation angle θ is provided.

Instead of the screw portion of the second rotor shown in FIG. 2, the shaft 22 is provided with irregularities like gears,
Irregularities are provided on the inner diameter side of the second rotor 20B so that the shaft can be inserted. However, when the shaft 22 is inserted into the inner diameter side of the second rotor 20B, the width of the groove is made larger than the width of the meshing teeth so as to be variable by a predetermined rotation angle θ. Further, a spring 2 is provided between the meshing teeth and the groove.
The provision of the damper 6 and the damper 27 has an effect of relieving a sudden collision. Similarly, when an actuator is provided to operate in a low-speed rotation region such as a washing or rinsing stroke where a large torque is required, the first rotor 20A and the second rotor 20 are forcibly forced as shown in FIG. By setting the center of the same magnetic pole of 20B to be aligned, the amount of effective magnetic flux by the permanent magnet facing the stator magnetic pole is increased, and high torque characteristics can be obtained.

Next, when operating in a high-speed rotation region such as a dehydration process, the second rotor 20B is shifted from the center of the same magnetic pole with respect to the shaft 22 so as to face the stator magnetic pole as shown in FIG. In other words, the amount of effective magnetic flux generated by the permanent magnet is reduced, in other words, there is a field weakening effect, and high output characteristics can be obtained in a high rotation region.

In the above description of the present invention, a four-pole machine has been described, but it is needless to say that the present invention can be applied to a six-pole machine, an eight-pole machine, and several tens of pole machines. As an example, FIG. 15 is a schematic diagram of a rotor of a permanent magnet type synchronous motor when the present invention is applied to an 8-pole machine. Needless to say, the rotor can be applied to an embedded magnet type or a surface magnet type.

FIG. 16 schematically shows a washing machine with a direct drive system and a gear combination system.

In FIG. 16, the other components of the washing machine are common, except for the presence or absence of a gear. FIG. 16 (a)
FIG. 16B shows a direct drive system, and FIG. 16B shows a gear combination system. In FIG. 16 (b), a gear 79 is provided between the electric motor 2 and a switching mechanism (77 in FIG. 1) for connecting or disconnecting the rotation axis of the washing / dewatering tub to / from the rotation axis of the pulsator (73 in FIG. 1). , And the gears may be built in the switching mechanism 77. Of course,
It goes without saying that the motor of the present invention can be applied to both of the above types.

[0077]

According to the permanent magnet type synchronous motor of the present invention, the rotor divided into the first field magnet and the second field magnet is arranged on the same axis. By changing the center of the magnetic pole of the magnetic magnet, there is an effect that the amount of effective magnetic flux by the permanent magnet facing the stator magnetic pole can be varied.

In particular, the weakening field of the spin-drying process of the motor of the washing machine can be easily achieved, which has a great effect on the wide range variable speed operation.

[Brief description of the drawings]

FIG. 1 schematically shows a washing machine in which a permanent magnet type synchronous motor of this embodiment is arranged.

FIG. 2 schematically shows a case where the center of the rotor magnetic poles of the electric motor of FIG. 1 is shifted (part 1).

FIG. 3 schematically shows a case where the rotor has the same magnetic pole center in the motor of FIG. 1;

FIG. 4 schematically shows a case where the center of the same magnetic pole of a rotor of the electric motor shown in FIG. 1 is shifted (part 2).

FIG. 5 shows various characteristics of the electric motor of FIG. 1 with respect to the rotational angular velocity.

FIG. 6 shows a control block diagram of the electric motor of FIG.

FIG. 7 shows an electric motor according to another embodiment of the present invention (actuator OFF state).

FIG. 8 shows an electric motor according to another embodiment of the present invention (actuator ON state).

FIG. 9 shows the inside of a rotor of an electric motor according to another embodiment of the present invention.

FIG. 10 shows the inside of a rotor of an electric motor according to another embodiment of the present invention.

FIG. 11 shows an electric motor according to another embodiment of the present invention (actuator ON state).

FIG. 12 shows a schematic view of an axial displacement measurement of a motor according to another embodiment of the present invention.

FIG. 13 is a schematic view showing a rotor of a motor according to another embodiment of the present invention (with a gap).

FIG. 14 shows an electric motor according to another embodiment of the present invention.

FIG. 15 is a schematic view showing a rotor of an electric motor according to another embodiment of the present invention (when applied to an 8-pole motor).

FIG. 16 is a schematic view showing an arrangement of a motor according to another embodiment of the present invention.

[Explanation of symbols]

2 ... motor, 10 ... stator core, 11 ... armature winding, 1
2 ... cooling path, 13 ... housing, 20 ... rotor, 20A
... 1st rotor, 20B ... 2nd rotor, 21 ... permanent magnet,
21A: First rotor permanent magnet, 21B: Second rotor permanent magnet, 22: Shaft, 23: Screw, 24: Stopper, 25: Stopper driving actuator, 26: Spring, 27: Damper, 101: Operation determining unit , 10
2. Current control, 103: Rotational coordinate converter, 104: Inverter, 105: Two-axis converter.

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[Procedure amendment]

[Submission date] July 23, 2001 (2001.7.2)
3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction contents]

Further, when working with the same electric motor, if the rotation direction of the rotor in the opposite, also in the opposite torque direction. Similarly, when working with the same generator, if the rotational direction of the rotor in the opposite, also in the opposite torque direction.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02K 1/22 H02K 1/22 Z 16/02 16/02 21/16 21/16 M 29/06 29 / 06 Z (72) Inventor Yasuo Notohara 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Research Laboratory, Hitachi, Ltd. (Reference) 3B155 BA03 BB15 HB10 LB18 LC15 LC28 MA02 MA05 MA08 5H002 AA02 AB04 AE06 AE07 5H019 BB20 BB24 CC03 EE04 5H621 BB07 GA04 GA16 HH01 JK02 JK11 5H622 AA03 CA01 CA07 CA12 CA13 CA14 CB01 PP01 PP14

Claims (15)

[Claims] A washing and dewatering tub rotatably supported on a rotating shaft in an outer tub; and a washing and dewatering tub rotatably supported on a bottom of the washing and dewatering tub about a rotating shaft concentric with the rotating shaft. A rotating body, a switching mechanism for connecting or disconnecting the rotating shaft of the washing and dewatering tub to or from the rotating shaft of the rotating body, and an electric motor, and causes the rotating body for stirring the inside of the washing tub to perform forward / reverse operation. In the washing machine that performs a washing or rinsing step and finally performs a dehydration step, the electric motor includes a stator having a primary winding and a rotor having a field magnet, and the field magnet has a rotating direction. The first field magnet in which magnetic poles having different polarities are sequentially arranged and the second field magnet in which magnetic poles having different polarities are sequentially arranged in the rotational direction are rotatable relative to the first field magnet. Wherein the first and second field magnets are fixed. And a mechanism for changing the phase of the combined magnetic pole of the first and second field magnets with respect to the magnetic pole of the first field magnet in accordance with the torque direction of the rotor. The mechanism for changing the torque in accordance with the direction of the torque is based on the balance between the direction of the torque generated in the rotor and the magnetic acting force between the first and second field magnets. A washing machine using an electric motor having means for aligning the same magnetic pole centers of the field magnets, and means for shifting the magnetic pole centers of the first and second field magnets as the torque directions generated in the rotor are reversed. 2. The washing machine according to claim 1, wherein said electric motor includes means for aligning said first and second field magnets at an initial position, and a magnetic pole center of said first and second field magnets. And a mechanism for changing the center of the magnetic pole with a change in the torque direction, wherein the first field magnet is fixed to a shaft,
The second field magnet is separated from the shaft, and the shaft and the second field magnet can be displaced within an angle of one magnetic pole, so that the center of the first field magnet and the second field magnet can be displaced. Washing machine using an electric motor in which the center of the magnetic pole of the magnet for use is shifted. 3. The electric motor according to claim 1 or 2, wherein the mechanism for changing the center of the magnetic pole in accordance with the change in the torque direction comprises fixing the first field magnet to a shaft, and changing the second field magnet. The magnet is separated from the shaft, and the shaft is connected to the screw portion of the bolt and the nut portion inside the second field magnet so as to have a screw function. Provide a stopper away from the
A washing machine using an electric motor with a servo mechanism that can change the stopper parallel to the shaft according to the rotation speed. 4. The electric motor according to claim 1, wherein a current supplied by a controller that controls said inverter according to a displacement of a composite magnetic pole position between said first field magnet and said second field magnet. An electric motor characterized in that the lead angle is corrected. 5. The electric motor according to claim 1, wherein said first field magnet is fixed to a shaft, and said second field magnet is fixed to said shaft.
The field magnet is separated from the shaft, and a screw portion of a bolt and a nut portion inside the second field magnet are connected to the shaft so as to have a screw function. The amount of displacement of the magnet for use in the axial direction is detected, and the advance angle of the current supply by the controller that controls the inverter is corrected so as to correspond to the deviation angle of the combined magnetic pole position between the first field magnet and the second field magnet. An electric motor characterized in that: 6. An electric motor according to claim 1, wherein said first field magnet is fixed to a shaft, and said second field magnet is fixed to said shaft.
An electric motor, wherein a field magnet is separated from a shaft, and a plurality of support mechanisms are provided between the second field magnet and the shaft so as to guide rotation, reciprocation and combined movement. 7. The rotating electric machine according to claim 1, wherein said first field magnet is fixed to a shaft, said second field magnet is separated from said shaft, and said second field magnet is separated from said shaft. A rotating electric machine wherein the second field magnet and the sleeve are fixed via a sleeve between the inside of the magnetic magnet and the shaft. 8. The rotating electric machine according to claim 7, wherein the sleeve is made of a non-magnetic material having higher electric resistivity than iron. 9. The electric motor according to claim 1, wherein said first field magnet is fixed to a shaft, and said second field magnet is fixed to said shaft.
The field magnet is separated from the shaft, and a plurality of springs are provided before and after the second field magnet to guide rotation, reciprocation, and combined movement of the second field magnet. Electric motor. 10. The electric motor according to claim 1, wherein the first field magnet is fixed to a shaft, the second field magnet is separated from the shaft, and the first field magnet is separated from the shaft. A concave portion is provided on the side surface of the first field magnet where the magnet and the second field magnet are in contact with each other, and the second field magnet is provided with a projection which also functions as the sleeve. Electric motor. 11. The electric motor according to claim 1, wherein
The first field magnet is fixed to a shaft, the second field magnet is separated from the shaft, and a stopper is provided at a position away from a side surface of the second field magnet. An electric motor comprising: a support mechanism for guiding a rotational motion, a reciprocating motion, and a composite motion with respect to a two-field magnet and a shaft. 12. The electric motor according to claim 1, wherein
The first field magnet is fixed to a shaft, the second field magnet is separated from the shaft, and the second magnet is separated from the rotor having the first field magnet by an air gap between the stator and the second magnet.
An electric motor wherein an air gap between a rotor having a field magnet and the stator is larger. 13. The electric motor according to claim 1, wherein
The first and second field magnets are opposed to the stator magnetic poles, and the first and second field magnets are relatively axially movable. Electric motor. 14. The washing machine according to claim 1, wherein when the electric motor is operated at a low speed, the center positions of the magnetic poles of the first field magnet and the second field magnet are made coincident with each other, so that the high speed and low load are achieved. A washing machine characterized by using an electric motor that operates while shifting the center positions of the magnetic poles of the first field magnet and the second field magnet during operation. 15. The washing machine according to claim 1, wherein in the washing or rinsing step, the center positions of the first field magnet and the second field magnet of the electric motor coincide with each other; A washing machine characterized by using an electric motor that operates by shifting the center position of the magnetic poles of the first field magnet and the second field magnet in the dehydration step.