JPH0667167B2 - Rotor insert type actuator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotor pinch type actuator suitable for use in a dust-resistant semiconductor or a factory related to biotechnology.

(Prior Art) Conventionally, a magnetic bearing has been used as a method of supporting a rotating body in a non-contact state. This magnetic bearing uses a magnetic attraction or repulsive force to obtain a supporting force for the shaft.

FIG. 14 is a sectional view of such a magnetic bearing type motor.

As shown in this figure, a high frequency motor 103 having a magnetic bearing is installed on a base 101 via a vibration absorbing buffer 102. The magnetic bearings include radial bearing units 104, 10 on both sides of the high frequency motor 103.
4, the thrust bearing unit 105 is arranged at one end of the rotor 106, and these units are configured to magnetically levitate the rotor 106 by electromagnetic force. An emergency bearing 110 is provided between the emergency bearing 110 and 106.

Further, the radial displacement of the rotor 106 is the radial sensor 107, and the displacement in the thrust direction is the thrust sensor 10.
8, the position of the rotor 106 is controlled to a predetermined position by adjusting the attraction force of the electromagnet of the magnetic bearing.

An example of the magnetic bearing of this type is disclosed in Japanese Patent Laid-Open No. 59-89820.

On the other hand, a direct drive type conveyance device using a linear pulse motor (hereinafter referred to as LPM) has been developed.
This type of prior art is described, for example, in Editors and Publishers "The Institute of Electrical Engineers", "Linear Motors and Their Applications," pages 124-127.

However, in this transfer apparatus, the transfer unit including the work is separated from the LPM and supported by a mechanical linear bearing. In other words, this LPM employs a mechanical structure that gives only the thrust required to move the transport section. In addition, there is an example in which a movable member is supported by an air bearing, but this cannot be used in a vacuum state, and there is a problem in support rigidity.

Further, there is known a DC brushless motor called a megatorque motor in which a thin ring-shaped rotor is sandwiched between stators on both inner and outer sides. As prior arts of this kind, for example, JP-A-59-63974 and JP-A-60-12.
5153, JP-A-60-141160, and the like.

(Problems to be Solved by the Invention) In the above-described conventional magnetic bearing, it is difficult to perform highly accurate positioning, and the structure has to be increased in size.

On the other hand, the transport device using the LPM has the following problems since it has a mechanical bearing.

(1) Mechanical frictional contact cannot be made, and dust is generated from this frictional contact portion.

(2) In a vacuum, the lubricating oil evaporates, polluting the atmosphere and burning the bearing.

(3) Noise and vibration are generated from the friction contact part.

(4) High precision positioning is difficult because it has mechanical contact parts.

Further, in the above-mentioned megatorque motor, since the torque per unit weight is large and the response is high, it has the advantage that high-speed delicate torque control can be performed and highly accurate operation is possible, but it has a mechanical bearing. In the above LP
It has the same problem as the transfer device using M, and is not particularly sufficient for use in the severe environment as described below.

In other words, in recent years, semiconductors and biotechnology-related factories that are resistant to dust, and compact rotary transfer devices that withstand use under high vacuum conditions have been desired, but products that can fully respond to this have been developed. The current situation is that it has not been done.

In view of the above situation, the present invention performs rotational drive in a non-contact state by a magnetic force between a stator and a rotor, has a large torque per unit weight, and is highly accurate and capable of high-speed rotation. An object of the present invention is to provide a compact rotor sandwiching type actuator that is directly driven.

(Means for Solving the Problems) In order to achieve the above object, the present invention is a rotor sandwiching type actuator, which has a core member arranged coaxially and having a plurality of pole pieces, A rotation driving magnetic pole excited by a rotation driving coil wound on the pole piece, and a suction magnetic pole excited by a suction coil wound on the core member adjacent to the rotation driving magnetic pole. Is disposed between the inner motor magnetic pole and the outer motor magnetic pole, and a stator equipped with an electromagnet, and the inner motor magnetic pole and the outer motor magnetic pole. A cup-shaped rotor having teeth arranged in a link and having a buoyancy force that balances with its own weight by the electromagnet, and displacement detection means for detecting relative displacement between the stator and the rotor, Control means is provided for adjusting the gap between the stator and the rotor based on the detection value from the displacement detection means, and for performing the step rotation drive in the non-contact state of the rotor.

(Operation) According to the present invention, the stator has the inner motor magnetic poles, the outer motor magnetic poles arranged coaxially, and the electromagnets that levitate the rotor, and has a ring shape between the inner motor magnetic pole and the outer motor magnetic pole. A rotor is provided and a part of the rotor faces the electromagnet.

Therefore, the rotor can be reduced in weight, and the magnetic force of the motor magnetic pole and the electromagnet keeps the weight in balance and keeps it out of contact, and the inner motor magnetic pole and the outer motor magnetic pole enable high torque driving, and High-precision control can be performed.

Further, based on the detection value from the displacement detection means, the control means can adjust the gap between the stator and the rotor to drive the rotation of the rotor in a non-contact state. In other words, in the attitude control of the rotor, the displacement state of the rotor is monitored by the electronic control unit via the displacement detecting means, and the exciting currents of the attraction magnetic pole and the electromagnet in the motor magnetic pole are adjusted according to the displacement state. It is accomplished by doing.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In FIGS. 1 to 3, reference numeral 1 denotes a stator, which has a ring-shaped housing 1a projecting a column 1b in the center,
Four inner motor magnetic poles 2a to 2d are coaxially fixed to the upper portion of the column 1b. That is, the central portions of the motor magnetic poles are arranged at intervals of 90 degrees.

On the other hand, in the inner peripheral part of the upper part of the ring-shaped housing 1a,
The outer motor magnetic poles 5a to 5d are fixed so as to face the inner motor magnetic poles 2a to 2d, respectively. The configuration of the motor magnetic pole will be described later in detail. Further, a projecting portion 1c is provided in the lower portion of the column 1b, and four electromagnets 3a to 3d are provided on the lower surface of the outer peripheral portion of the projecting portion 1c.
(3b and 3d are not shown, but they are located before and after in FIG. 2) are arranged at equal intervals.

Reference numeral 4 denotes a cup-shaped rotor, which has a table surface portion 4a, a ring-shaped side surface portion 4b, and a shelf portion 4c, and faces the inner motor magnetic poles 2a to 2d and the outer motor magnetic poles 5a to 5d of the ring-shaped side surface portion 4b. In the portion to be formed, tooth rows are formed which are aligned on a concentric circle with a constant pitch. The shelf 4c is attached so as to face the electromagnets 3a to 3d. 6a-6
e is a displacement detector, 7 is a control means, 8 is an electronic control device, 8
-1 is a CPU (Central Processing Unit), 8-2 is a memory, 8-
3 is an input interface, 8-4 is an I / O interface, 8-5 is an MDI (manual data input) device, 9 is a drive circuit, 10 is a power supply, 11 is a first displacement detection reference plane (target), 12 Is a second displacement detection reference surface.

Next, an outline of the structure and operation of this rotor sandwiching type actuator will be described.

(1) Holding Non-Contact State of Rotor The rotor 4 is, as shown in the figure, an inner motor magnetic pole that is formed on the inner and outer surfaces of the ring-shaped side surface portion 4b of the rotor 4 and that faces the tooth row. XY is attracted by the magnetic force of the attraction magnetic poles of 2a to 2d and the outer motor magnetic poles 5a to 5d.
The position in the Z direction is held while the position in the Z direction is levitated by the magnetic force of the electromagnets 3a to 3d.

(2) Rotational Drive of Rotor As shown in the figure, the rotor 4 has the inner motor magnetic poles 2 with tooth rows formed on both sides of the ring-shaped side surface portion 4b of the rotor 4.
The inner motor magnetic poles 2a to 2d and the outer motor magnetic pole 5a are provided between a to 2d and the outer motor magnetic poles 5a to 5d.
It is rotationally driven by the magnetic force of the rotational driving magnetic pole of 5d.

(3) Attitude control of rotor The attitude control of the rotor 4 is performed by the inner motor magnetic poles 2a to 2d and the outer motor magnetic poles 5a to 5d on which magnetic force acts on the rotor 4.
This is performed by adjusting the respective exciting currents of the attraction magnetic poles and the electromagnets 3a to 3d. That is, the positioning is performed by adjusting the exciting magnetic poles of the motor magnetic poles and the exciting currents in the electromagnets so that the cup-shaped rotor 4 becomes horizontal. The distance between the fixed portion and the rotor is detected by the displacement detectors 6a to 6e, and the electronic control unit 8 performs appropriate attitude control.

As shown in FIGS. 1 and 2, the ring-shaped side surface portion 4b of the rotor 4 (hereinafter referred to as the rotor) having the table surface portion 4a is aligned concentrically with a constant pitch on both inner and outer surfaces. A tooth row is formed, and an inner motor magnetic pole 2a having a suction magnetic pole and a rotation driving magnetic pole facing each other.
˜2d and outer motor poles (discussed in detail below) 5a-5d. Then, the rotor 4 is magnetically attracted, and X
It is held in a non-contact state in the Y direction and driven to rotate.

Further, the shelf portion 4c provided at the lower portion of the rotor 4 is made of a ring-shaped flat plate, and the electromagnet 3 provided at the lower portion of the column 1b.
The rotor 4 is magnetically levitated in the Z direction due to the magnetic force of the electromagnets 3a to 3d that faces the a to 3d.

Next, the structure of the motor magnetic pole will be described with reference to FIG. 4 by taking the outer motor magnetic pole as an example.

A suction coil for attracting the rotor 4 is wound around the base of the core member 21 and a rotation driving coil is wound around the tip of each motor magnetic pole. That is, the attraction magnetic pole that magnetically attracts the rotor 4 to perform non-contact support in the XY directions and the rotation driving magnetic pole that magnetically drives the rotor 4 to rotate are integrated. That is,
The core member 21 is constructed by stacking ferromagnetic materials such as electromagnetic steel plates punched into a concatenated shape having a concave shape, and the suction coils 26 and 27 are wound around the outer periphery of each recess of the core member 21 so as to have polarities opposite to each other. I am wearing.

Each tip of the core member 21 has a first pole piece, a second pole piece, and a third pole piece.
It is composed of a pole piece and a fourth pole piece, and the rotation driving coils 28, 29, 30, and 31 are wound around the respective pole pieces, and the first magnetic pole 22, the second magnetic pole 23, the third magnetic pole 24, and the fourth magnetic pole. 25 (see FIG. 4 (a)). These magnetic poles 22,
The pitch of the teeth provided on 23, 24, 25 is the same as the pitch of the teeth of the rotor 4, but the pitch of the teeth of the magnetic poles is deviated, and when the first magnetic pole 22 is used as a reference,
The magnetic poles 23 are arranged so as to have a 1/2 pitch, the third magnetic poles 24 have a 1/4 pitch, and the fourth magnetic poles 25 are arranged so as to be displaced by 3/4 pitch relative to the pitch of the teeth of the rotor 4.

Next, the operation of this motor magnetic pole will be described with reference to FIG.

(1) When a current in the direction of the arrow shown in the drawing (to be the positive direction) is passed only through the suction coils 26 and 27, a magnetomotive force is generated, and a magnetic flux flows as shown in FIG. 5 (a).

(2) When a current is passed only through the rotation drive coils 28 and 29 that excite the first magnetic pole and the second magnetic pole, a magnetomotive force is generated, and a magnetic flux flows as shown in FIG. 5 (b). When a current is passed in the negative direction, the direction of magnetomotive force is reversed, and the magnetic flux also flows in the opposite direction. The same applies to the rotation drive coils 30 and 31 that excite the third magnetic pole and the fourth magnetic pole.

Here, a certain constant current Ic is passed through the suction coil. That is, the magnetomotive force shown in FIG. 5 (a) is generated to flow the magnetic flux, and at the same time, the rotary drive coils 28, 2
When a positive current Ia is applied to the first magnetic pole 22, a current Ic
And the magnetomotive force of the current Ia strengthen each other, while the magnetomotive forces of the current Ic and the current Ia cancel each other at the second magnetic pole 23, and the rotor 4 generates a restoring force that stabilizes at the position shown in FIG. 5 (b). . That is, an attempt is made to stabilize at a position where the convex portions of the teeth of the first magnetic pole 22 and the convex portions of the teeth of the rotor 4 coincide with each other. Next, when the current Ia is set to zero and the current Ib is set to positive, the magnetic flux tends to flow through the third magnetic pole 24, and a rotational force is generated in the rotor 4 so as to stabilize at the position shown in FIG. 5 (c), Rotor 4
Rotates by 1/4 pitch.

Next, if the current Ib is made zero and the current Ia is made negative, the second
Since the magnetomotive force for the magnetic pole 23 is strengthened and the magnetic flux flows,
Furthermore, it rotates 1/4 pitch. In this way, 1a
By switching the currents of the rotation driving coils 28, 29 and 30, 31 in the order of (positive) → Ib (positive) → 1a (negative) → Ib (negative), the rotor 4 rotates every quarter pitch. Will be done.

With this configuration, non-contact support of the rotor and rotational drive of the rotor are achieved by a compact motor magnetic pole and a magnetic pole stone for magnetic levitation in the Z direction, and the conventional mechanical bearing mechanism such as a rolling bearing is completely abolished. can do.

Next, the attitude control of the rotor will be described.

As shown in FIGS. 1 to 5, the first displacement detection reference surface (target) 11 and the bottom surface of the shelf portion 4c are provided on the side surface of the rotor other than where the tooth rows are formed. The displacement detection reference plane 12 is set.

On the other hand, the first displacement detectors 6a and 6b are provided on the inner peripheral surface of the side surface of the housing so that the two directions thereof are orthogonal to each other.
Further, the second displacement detectors 6c to 6e are arranged on the concentric circles at the bottom of the housing and at intervals of 120 degrees so as to face the second displacement detection reference surface 12.

Therefore, first, an exciting current is passed through the motor magnetic poles and the electromagnets so as to balance the magnetic forces between the motor magnetic poles and the electromagnets acting on the rotor 4, and the output signals from the displacement detectors 6a to 6e are obtained to obtain the rotors. 4 is set in a horizontal state, the origin position is set, and the value of the exciting current at this time is stored in the memory 8-2 of the electronic control unit 8. That is, the motor magnetic poles 2a to 2d, 5
The attraction magnetic poles a to 5d and the exciting currents of the electromagnets 3a to 3d are read from the input interface 8-3 of the electronic control unit 8 and stored in the memory 8-2, and as an initial value of the unbalance amount from the rotating shaft. To use.

Therefore, when an exciting current is applied to the rotation driving coil of the motor magnetic pole, the rotor 4 is driven to rotate and the table rotates. At this time, a microstep voltage (described in detail later) is applied to the rotation driving coil. The position of the rotor 4 is stored in advance as an origin position, and the displacement amount, that is, the rotation angle is determined by the number of pulses applied to the rotation driving coil of the motor magnetic pole from this position, and the position of the rotor 4 is controlled. be able to.

Here, when the number of divisions of microsteps is m, the rotor can be positioned at a minute angle of 2π / N · m (rad).

Further, the distances of the rotor 4 in the XY directions are determined by the displacement detectors 6c based on the detection signals from the first displacement detectors 6a and 6b.
The electronic control unit 8 can monitor the Z-direction distance and inclination of the rotor 4 based on the detection signals from 6e.

Note that the number of displacement detectors is not limited to this number,
It can be increased appropriately. Also, this arrangement can be changed appropriately.

Further, the rotor can be controlled as follows.

First, the origin position of the rotor 4 is determined by a photo sensor, a dog switch, etc., and the rotor 4 is supported in a non-contact manner at this position. That is, an exciting current is made to flow in advance through the drive circuit 9 to the motor magnetic pole and the electromagnet to bring the rotor 4 into a non-contact state.

Next, in the non-contact state, the detected value from each displacement detector is read into the electronic control unit 8 through the input interface 8-3, and the read value and the reference value of each displacement detector (become a reference. (Void value) is compared, and the deviation becomes zero, via the I / O interface 8-4,
In the drive circuit 9, the exciting current value of the attraction coil and electromagnet in each motor magnetic pole is adjusted.

By thus performing the feedback control, it is possible to smoothly control the attitude of the rotor.

With such a configuration, it is possible to obtain a non-contact type rotor pinch type actuator which has a large torque per unit weight and is highly accurate and capable of high-speed operation.

According to the above embodiment, the case where four motor magnetic poles and electromagnets are arranged at concentric circumferential positions has been described, but as shown in FIGS. 6 and 7, the motor magnetic poles and electromagnets [3e 3g (3f is not shown, but is located in front of FIG. 7)] are arranged at equal intervals. That is, the center angles of the inner motor magnetic poles 2e to 2g and the outer motor magnetic poles 5e to 5g are arranged at θ, that is, at intervals of 120 degrees.

Further, as shown in FIG. 8, the inner motor magnetic pole 2 and the outer motor magnetic pole 5 may be arranged in a vertically divided arrangement, and as the electromagnet, one ring-shaped electromagnet 3h may be provided. In this case, the electromagnet 3h only performs magnetic levitation in the Z direction, and the tilt of the rotor 4 is controlled exclusively by adjusting the exciting current of the attraction magnetic poles of the motor magnetic poles divided into the upper and lower portions.

Next, the micro step drive of the rotor will be described.

Here, the micro-step drive is a method of driving a two-phase current having a phase difference of 90 degrees in two windings of a motor magnetic pole to drive the motor as a synchronous motor. A waveform as shown in Figure 9 is provided. FIG. 10 is a block diagram of a microstep drive system, in which 41 is a ring counter and 42 and 43.
Is a ROM, 44 and 45 are D / A converters, 46 and 47
Is a drive amplifier, and the rotation drive coils 28 to 31 of the outer motor magnetic pole 5 are connected to the drive amplifiers 46 and 47 and thereafter.

The drive circuit for the suction coils 26 and 27 is omitted here.

As shown in this figure, when the movement command value is input to the ring counter 41, the waveform data stored in the ROMs 42 and 43, that is, the sine and cosine values are read out, and D
The analog amount is input to the drive amplifiers 46 and 47 via the / A converters 44 and 45, amplified, and added to the rotation drive coils 28, 29, 30 and 31. In the waveform, the ratio of the A phase to the B phase is determined by the electrical angle position (time), which is output according to the electrical angle position to move the rotor 4. If a voltage amplifier is used as the drive amplifier, passive damping can be expected. With this configuration, the rotor 4 can move smoothly and can be positioned at a minute distance.

By the way, since this rotor pinch type actuator drives the rotor in a non-contact state, mechanical damping with respect to the movement of the rotor is very small. Therefore, even if the micro step drive is performed, some vibration is accompanied. In order to suppress this vibration, it is configured as follows.

As shown in FIGS. 1 and 2, a case where a total of four motor magnetic poles are arranged at concentric positions at 90-degree intervals will be described.

Here, the phases of the plurality of motor magnetic poles arranged in the rotation direction with respect to the teeth of the rotor 4 are shifted from each other by π / 4. That is, at some point, the inner motor magnetic pole 2a,
In the rotation driving coil of 2c, the magnetomotive force as shown in FIG. 11 (a) is generated, while in the rotation driving coil of the inner motor magnetic poles 2b and 2d,
The respective motor magnetic poles are arranged so as to generate a magnetomotive force as shown in FIG.

Further, the outer motor magnetic poles 5a to 5d are similarly arranged.

In this way, when the position of the motor magnetic pole is shifted by π / 4 in terms of electrical angle, the rotational torque characteristics are made uniform, and damping is greater than in the case of in-phase arrangement, and smooth driving is possible. Becomes That is, it is possible to improve the resolution and reduce the vibration.

In the above, the case of the micro step drive has been described, but in the case of a normal step motor, the pattern is as shown in FIG. That is, when the motor magnetic pole I (inner motor magnetic pole 2a, outer motor magnetic pole 5a or inner motor magnetic pole 2c, outer motor magnetic pole 5c) is one-phase excitation, motor magnetic pole II (inner motor magnetic pole 2b, outer motor magnetic pole 5b or inner motor magnetic pole 5b). 2d, the outer motor magnetic pole 5d) is a two-phase excitation, and vice versa.

Here, plus and minus in the table are polarities of the coil voltage (or current) at the time of bipolar driving of the step motor.

As described above, damping can be performed by shifting the excitation phase not only in the micro step drive but also in the case of a normal step motor.

According to the above-mentioned embodiment, the motor magnetic poles 2b, 5b, 2
The case where the phases of d and 5d are advanced by π / 4 with respect to the motor magnetic poles 2a, 5a, 2c and 5c has been described, but conversely, the motor magnetic poles 2b and 5b with respect to the motor magnetic poles 2a, 5a, 2c and 5c, 2d and 5d may be delayed by π / 4. In this case, it is the same as the rotation direction of the rotor 4 is changed. Furthermore, even if n × π / 4 (n = 1, 3, 5, 7) is advanced or delayed, the above-described effects can be obtained. That is, when one of the two is two-phase excitation, the other one is preferably one-phase excitation.

Next, one embodiment of the position closed loop control of this rotor sandwiching type actuator will be described with reference to FIG.

Here, a traveling direction position detector is provided. The motor magnetic pole and the traveling direction position detector are supported and fixed by the fixed frame. Further, a drive circuit for the suction coils 26, 27, a displacement detector, a gap control circuit, etc. are omitted.

In the figure, 51 is a deviation counter that outputs an error between the current position and the movement command value, 52 is a D / A converter, and 53 is a PID.
A controller including an adjuster and the like, 54 is a code discriminator,
Whether to advance or delay the phase, that is, to output a plus or minus signal. 55 is an absolute value circuit and 56 is a phase output device, which is normally fixed at 90 degrees. 57 is a phase adder / subtractor, 58 and 59 are ROMs, 60 and 61 are D / A converters, 62 and 63 are multipliers, 64 and 65 are drive amplifiers,
A traveling direction position detector 66 detects the phase of the rotor 4 with respect to the teeth. The waveform is output as, for example, a sine wave or a cosine waveform. 67 is a position converter, for example, R
/ D (resolver / digital) converter, which outputs the current phase output to the phase adder / subtractor 57 and the speed output to the addition point 68 to form a speed loop. Also,
A current position signal is output from the position converter 67 to the deviation counter 51 to form a position loop.

With this configuration, it is possible to prevent step-out which is likely to occur in the case of open loop control.

The structure of the rotor pinch type actuator of the present invention can be variously modified according to the expected weight and shape of the rotor or the weight of an object placed on the table surface. In particular, the arrangement of the motor magnetic poles and electromagnets and the structure of the rotor can be appropriately modified.

Further, although the example of the digital control means is shown in the above-mentioned embodiment, the conventional PID adjustment can be performed by using an analog circuit.

The present invention is not limited to the above embodiment,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described in detail above, according to the present invention, the rotor sandwiching type actuator is arranged coaxially and has a core member having a plurality of pole pieces. A rotation driving magnetic pole excited by a rotation driving coil wound around the core and a suction magnetic pole excited by a suction coil wound on the core member adjacent to the rotation driving magnetic pole are integrated. And a stator provided with an inner motor pole and an outer motor pole, and an electromagnet, and is disposed between the inner motor pole and the outer motor pole and faces each of the motor poles and has a constant pitch. A cup-shaped rotor in which aligned tooth rows are provided in a ring shape and which receives a buoyancy force balanced by its own weight by the electromagnet, a displacement detection means for detecting relative displacement between the stator and the rotor, and the displacement detection Since the gap between the stator and the rotor is adjusted based on the detection value from the means, and the control means for performing the step rotation drive in the non-contact state of the rotor is provided, (1) It can rotate in a non-contact state, and its control is extremely smooth.

(2) A direct drive type actuator having a large torque per unit weight and capable of high-speed operation with high accuracy is constructed, and its configuration is simple and compact.

(3) It is not necessary to supply electricity to the rotor, and the rotor is lightweight, so the rotor moves quickly and the response is high.

(4) To drive, it is only necessary to provide the rotor with teeth, and since the rotation drive coil, suction coil and electromagnet are provided on the stator side, the heat generated by the coil is generated by heat conduction on the stator side. It can be effectively absorbed and does not cause the temperature rise of the rotor.

(5) No dust is generated because no mechanical bearing is required.

It can also be used in vacuum.

No noise or vibration from the drive source.

Highly accurate positioning is possible.

No maintenance such as refueling is required.

Thus, according to the present invention, there are various advantages, and in particular,
It is possible to obtain a rotor pinch type actuator that can be used in a harsh environment such as a high vacuum atmosphere in a dust-free semiconductor factory, a biotechnology-related factory, or a space factory.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view of a rotor pinching type actuator showing an embodiment of the present invention, and FIG. 2 is a II-I of FIG.
A sectional view taken along the line I ', FIG. 3 is an overall configuration diagram of a rotor sandwiching type actuator showing an embodiment of the present invention, FIG. 4 is a configuration diagram of a motor magnetic pole, FIG. 5 is an operation explanatory diagram of a motor magnetic pole, and FIG. FIG. 7 is a partially cutaway plan view of a rotor pinching type actuator showing another embodiment of the present invention, and FIG. 7 is a VII-V of FIG.
II ′ line sectional view, FIG. 8 is a partially cutaway sectional view of a rotor sandwiching type actuator having a ring-shaped electromagnet, and FIGS. 9 and 11 are microstep drive current waveform diagrams, FIG.
FIG. 0 is a microstep drive system configuration diagram, FIG. 12 is an excitation sequence diagram, FIG. 13 is a closed loop control system configuration diagram, and FIG. 14 is a sectional view of a conventional magnetic bearing type motor. 1 ... Stator 2, 2a-2d, 2e-2g ... Inner motor magnetic pole, 3a-
3d, 3e-3g, 3h ... Electromagnet 4 ... Rotor 5, 5a-5d, 5e-5g ... Outer motor magnetic pole, 6a-
6e ... Displacement detector 8 ... Electronic control device 9 ... Driving circuit 10 ... Power supply 11 ... First reference plane 12 ... Second reference plane 21 ... Core member 22 ... First magnetic pole 23 ... Second magnetic pole 24 ... Third magnetic pole 25 ... 4th magnetic pole 26, 27 ... Suction coil 28-31 ... Rotation drive coil

Claims (8)

[Claims] 1. (a) A rotary drive magnetic pole, which is coaxially arranged, has a core member having a plurality of pole pieces, and is excited by a rotary drive coil wound on the pole piece, and A stator provided with an inner motor magnetic pole and an outer motor magnetic pole, which are integrated with an attracting magnetic pole excited by an attracting coil wound on the core member adjacent to the rotation driving magnetic pole; b) A tooth row arranged between the inner motor pole and the outer motor pole, facing each of the motor poles and aligned with a certain pitch is provided in a ring shape, and is self-weighted by the electromagnet. A cup-shaped rotor that receives a buoyancy force that balances with (c) a displacement detection unit that detects a relative displacement between the stator and the rotor; and (d) the stator based on a detection value from the displacement detection unit. The gap between the rotors Rotor entrapment type actuator characterized by comprising a control means for settling, and performs the step rotation of a non-contact state of the rotor. 2. The tooth row of the rotor is formed on the inner and outer surfaces of a ring-shaped rotor, and the rotor is provided with a table surface portion continuously provided on an upper portion of the tooth row. The rotor sandwiching type actuator according to item 1. 3. The rotor sandwiching type actuator according to claim 1, wherein at least three motor magnetic poles are arranged at concentric circumferential positions on the stator. 4. The gap control means for adjusting the gap between the stator and the rotor by changing the exciting current of the suction coil based on the detection value from the displacement detection means, and the rotation drive coil. The rotor pinching type actuator according to claim 1, further comprising: a rotation drive control unit that changes a current to drive rotation of the rotor in a non-contact state. 5. The rotation drive control means comprises means for supplying sine-wave and cosine-wave currents to the rotation drive coil, and performing microstep drive by the currents flowing in the respective phases of these rotation drive coils. The rotor sandwiching type actuator according to claim 1, wherein: 6. A means for detecting the displacement in the rotational direction of the rotor by the displacement detecting means at the time of the micro step driving, and performing closed loop control so that a constant excitation lead angle is obtained based on the detected value. The rotor sandwiching type actuator according to claim 5, characterized in that. 7. The rotor sandwiching type according to claim 1, wherein the plurality of motor magnetic poles arranged in the rotation direction of the rotor are arranged so that each excitation phase is shifted by π / 4. Actuator. 8. The displacement detecting means comprises means for detecting vertical movement, lateral movement and rotation, and controlling the rotor to a position preset by the control means based on the detected values. The rotor sandwiching type actuator according to claim 1, wherein: