JPS62135255A - Rotor-nipped type actuator - Google Patents

Abstract

PURPOSE:To make the rotor as lightweight and as high in torque as possible by providing internal/external motor poles and an electromagnet for rotor levitation to the rotor and by arranging a ring-shape rotor between both poles. CONSTITUTION:An actuator is composed of a stator 1 and a rotor 4. With an electromagnet 3 provided at the lower strut 1c of a pillar 1b of the stator 1 the shelf 4c of the rotor 4 is attracted and the magnetic levitation is caused in the direction of Z-axis. An external motor pole 5 is provided opposing to an internal pole 2 of the pillar 1b on the upper inside circumference of a housing 1a. In this clearance the side surface 4c of the rotor 4 is positioned, to which the dentition with a regular pitch is formed. Thus, the rotor 4 is magnetically attracted and held in a non-contact condition in the directions of X-axis and Y-axis while rotated and driven. Furthermore, the distance of the rotor 4 is detected with a displacement detector 6 and controlled by the electronic control device to a proper position.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a rotor sandwiched actuator suitable for use in semiconductor or biotechnology related factories where dust is avoided.

(Prior Art) Magnetic bearings have conventionally been used as a method of supporting a rotating body in a non-contact manner. This magnetic bearing uses magnetic attraction or repulsion 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 1 has a magnetic bearing on a base 101 via a vibration absorbing buffer 102.
03 is installed. The magnetic bearings include radial bearing units (104, 104) on both sides of the crystal frequency motor 103.
and a thrust bearing unit 105 is arranged at one end of the rotor 106, and these units are @
The rotor 106 is magnetically levitated by magnetic force, and an emergency bearing 110 is provided between the outer frame 109 and the rotor 106.

Further, the displacement of the rotor 106 in the radial direction is measured by a radial sensor 107, and the displacement of the rotor 106 in the thrust direction is measured by a thrust sensor 107.
8, and the position of the rotor 106 is controlled to a predetermined position by adjusting the attractive force of the 1i magnet of the magnetic bearing.

An example of this kind of magnetic bearing is JP-A-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 kind of prior art is described, for example, in the editor and publisher, ``IEEJ,'' ``Linear Motors and Their Applications,'' pages 1124-127.

However, in this transfer unit/station, the transfer unit including the workpiece is separated from the LPM and supported by a mechanical linear bearing. In other words, this LPM employs a mechanical structure that provides only the thrust necessary to move the transport section. There are other examples of supporting movable members using air bearings, but these cannot be used in vacuum conditions and have problems in terms of support rigidity.

Furthermore, a DCC brushless morph called a megatorque motor is known in which a thin ring-shaped rotor is sandwiched between inner and outer stators. This type of prior art includes, for example, JP-A-59-83914 and JP-A-60-125.
153, JP-A-60-141160, and the like.

(Problems to be Solved by the Invention) The above-described conventional magnetic bearings have difficulty in positioning with high precision, and moreover, the structure has to be increased in size.

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

(1) a Mechanical frictional contact cannot be avoided, and dust is generated from this frictional contact area.

(2) In a vacuum state, lubricating oil evaporates and the atmosphere is
(This will cause bearing burnout as well as damage to the bearing.

(3) Noise and vibration are generated from frictional contact parts.

(4) High precision positioning is difficult because there are mechanical contact parts.

Furthermore, in the above megatorque motor, the unit ff
Since the torque per liter is large and the responsiveness is high, it has the advantage of being able to perform delicate torque control at high speeds and operate with high precision. It had the same problems as the device, and was particularly unsatisfactory for use in the harsh environments described below.

In other words, in recent years, there has been a desire for a compact rotary conveyance device that can withstand use in dust-free semiconductor and biotechnology-related factories and under high vacuum conditions, but as of yet, no one has been developed that can fully meet this demand. The current situation is that this is not the case.

In view of the above circumstances, the present invention provides non-contact rotational drive using magnetic force between the stator and rotor, has large torque per unit weight, and is capable of high-speed rotation with high precision. The purpose of the present invention is to provide a compact rotor-pinch type actuator that is directly driven.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides: (a) a stator including an inner motor magnetic pole, an outer motor magnetic pole, and an electromagnet arranged coaxially; b) a cup-shaped rotor disposed between the inner motor magnetic pole and the outer motor magnetic pole and receiving a buoyancy force balanced with its own weight by the electromagnet;
c) displacement detection means for detecting relative displacement between the stator and the rotor; (d) adjusting a gap between the stator and the rotor based on a detected value from the displacement detection means; A control means for rotationally driving in a non-contact state is provided.

(Function) According to the present invention, the stator has an inner motor magnetic pole, an outer motor magnetic pole, and a T4 magnet that levitates the rotor, which are arranged coaxially, and a ring shape is formed between the inner motor magnetic pole and the outer motor magnetic pole. A rotor is disposed, and a portion of the rotor faces the electromagnet.

Therefore, the weight of the rotor can be reduced, and the weight is balanced by the magnetic force of the motor magnetic poles and electromagnets, and the rotor is held in a non-contact manner.
It is possible to drive with high torque and perform highly accurate control.

Furthermore, the control means can adjust the gap between the stator and the rotor based on the detected value from the displacement detection means, and can drive the rotor to rotate in a non-contact state. In other words, in the attitude control from mouth to evening, the displacement state of mouth to evening is monitored by the electronic control device via the displacement detection means, and depending on the displacement state, the attraction magnetic poles and the electromagnets in the motor magnetic poles are each excited. This is accomplished by adjusting the current.

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

In FIGS. 1 to 3, l is a stator, which has a ring-shaped housing la with a support 1b protruding from the center;
Four inner motor magnetic poles 2a to 2d are fixed coaxially to the upper part of the support column 1b. That is, the center portions of the motor magnetic poles are arranged at 90 degree intervals. On the other hand, the inner circumference of the upper part of the ring-shaped housing la is provided with inner motor magnetic poles 2a to 2.
d, the outer motor magnetic poles 5a~
Fix 5d. Regarding the configuration of the motor magnetic poles,
This will be described in detail later. Further, an overhang IC is provided at the lower part of the support column 1b, and four electromagnets 3a to 3d (3b) are provided on the lower surface of the outer periphery of the overhang IC.

3d (not shown, but located before and after FIG. 2) are arranged at equal intervals. 4 is a cup-shaped rotor, which has a table surface portion 4a, a side surface portion 4b of a ring 4χ, and a shelf portion 4C, and faces the inner motor magnetic poles 2a to 2d and outer motor magnetic poles 5a to 5d of the ring-shaped side surface portion 4b. A row of teeth arranged concentrically at a constant pitch is formed in the area where the teeth are formed. Further, the shelf portion 4C is mounted so as to face the electromagnets 3a to 3d. 6a to 6e are displacement detectors, 7 is a control means, 8 is an electronic control unit, 8-1 is a CPU (central processing unit), 8-2 is a memory, 8-3 is an input interface, and 8-4 is! 10 interfaces, 8-5 is M
DI (Manual Data Input) device, 9 is a drive circuit, 10 is a power supply, 11 is a first displacement detection reference surface (target), and 12 is a second displacement detection reference surface.

Next, the structure and operation of this rotor sandwiched actuator will be outlined.

(1) Keeping the rotor in a non-contact state As shown in the figure, the rotor 4 has an inner motor magnetic pole 2a disposed opposite to a row of teeth formed on the inner and outer surfaces of the ring-shaped side surface portion 4b of the rotor 4. ~2d and outer motor pole 5
□ is attracted by the magnetic force of the attracting magnetic poles a to 5d and its position in the XY direction is maintained, and it is also levitated by the magnetic force of the electromagnets 33 to 3d and its position in the Z direction is maintained.

(2) Rotation drive of the rotor As shown in the figure, the rotor 4 has tooth rows formed on both sides of the ring-shaped side surface of the rotor 4.
2d and the outer motor magnetic poles 5a to 5d, and is rotationally driven by the magnetic force of the rotational driving magnetic poles of the inner motor magnetic pole and the outer motor magnetic pole.

(3) Attitude control of the rotor Attitude control of the rotor 4 is performed by controlling the inner motor magnetic poles 2a to 2d and the outer motor magnetic poles 5a to 5d, where magnetic force acts on the rotor 4.
This is done by adjusting the magnetic poles for attraction and the excitation current of each of the electromagnets 3a to 3d. That is, positioning is performed by adjusting the excitation current in the attraction magnetic pole and electromagnet of each motor magnetic pole so that the cup-shaped rotor 4 is in a horizontal state.The distance between the fixed part and the rotor is determined by displacement detectors 6a to 6e. is detected, and the electronic control device 8 performs appropriate attitude control.

As shown in FIGS. 1 and 2, on both the inner and outer surfaces of the ring-shaped side surface portion 4b of the rotor 4 (hereinafter referred to as rotor) having the table surface portion 4a, concentric circles are arranged at a constant pitch. An inner motor magnetic pole 2a has a tooth row formed thereon, and has an attraction magnetic pole and a rotational drive magnetic pole opposing thereto.
2d and outer motor magnetic poles (described in detail below) 5a to 5d. Therefore, the rotor 4 is magnetically attracted to X
It is held in a non-contact state in the Y direction and is rotationally driven. Further, the shelf section 4C provided at the lower part of the rotor 4 is made of a ring-shaped flat plate, and is oriented i toward the electromagnets 33 to 3d provided at the lower part of the support column 1b. magnetically levitates in the Z direction.

Next, the structure of the motor magnetic pole will be explained using FIG. 4, taking the outer motor magnetic pole as an example.

A suction coil for attracting the rotor 4 is wound around each motor magnetic pole at the base of the core member 21, and a rotation driving coil is wound around the tip. In other words, an attraction magnetic pole that magnetically attracts the rotor 4 and provides non-contact support in the XY directions and a rotational drive magnetic pole that magnetically rotationally drives the rotor 4 are integrated. That is, it is constructed by stacking ferromagnetic materials such as electromagnetic and steel plates punched into connected concave shapes, and branching coils 26 and 27 are arranged around the outer periphery of each concave part of this core member so that the polarities are opposite to each other. It is wrapped in Each tip of this core member consists of a first pole piece, a second pole piece, a third pole piece, and a fourth pole piece, and each pole piece is wound with a rotational drive coil 28, 29, 30° 31, respectively. The first magnetic pole 22, the second magnetic pole 22, Magnetic i23, third magnetic pole 2
4. A fourth magnetic pole 25 [see FIG. 4 (, 1)] is formed. The pitch of the teeth provided on these magnetic i22, 23, 24, 25 is the same as the pitch of the teeth of the rotor, but the pitch of the teeth of the magnetic poles is different, and when the first magnetic pole 22 is used as a reference, The second magnetic pole 23 is deviated by 1/2 pitch, the third magnetic pole 24 is deviated by 1/4 pitch, and the fourth magnetic pole 25 is deviated by 3/4 pitch relative to the pitch of the teeth of the rotor.

Next, the operation of this motor magnetic pole will be explained using FIG. 5.

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

(2) When current is applied only to the rotation drive coils 28 and 29 that excite the first and second magnetic poles, a magnetomotive force is generated, and the fifth
Magnetic flux flows as shown in Figure (b).

Furthermore, when current flows in the negative direction, the direction of the magnetomotive force is reversed, and the magnetic flux also flows in the opposite direction. The same can be said of the rotational drive coils 30 and 31 that excite the third and fourth magnetic poles.

Here, a certain constant current IC is caused to flow through the attraction coil. In other words, the magnetomotive force shown in FIG. 5(a) is generated and magnetic flux is caused to flow, and at the same time
When a positive current 1a is applied to 9, the current 1c is applied to the first porcelain plume 22.
The magnetomotive forces of the current rc and the current (a) strengthen each other, while the magnetomotive forces of the current rc and the current (a) cancel each other out at the second magnetic pole 23, creating a restoring force that stabilizes the rotor 4 at the position shown in FIG. 5(b). In other words, the convex portions of the teeth of the first magnetic scraper 22 and the convex portions of the teeth of the rotor 4 attempt to stabilize at a position where they collide.

Next, when the current 1a is made zero and the current 1b is made positive, the third
A magnetic flux tends to flow through the magnetic poles 24, and a rotational force is generated in the rotor 4 so that it is stabilized at the position shown in FIG. 5(c), and the rotor 4 rotates by 1/4 pitch.

Next, when the current Ib is made zero and the current [a is made negative, the second
Since the magnetomotive force against the magnetic pole 23 strengthens each other and magnetic flux flows,
Further, rotate by 1/4 pitch. In this way, the rotational drive coil 2B changes from ra (positive) to Ib (positive) - 1a (negative) - 1b (negative).

By switching the currents of 29 and 30.31,
The rotor 4 rotates every 1/4 pitch.

With this configuration, non-contact support of the rotor and rotational drive of the rotor are achieved using compact motor magnetic poles and electromagnets that perform magnetic levitation in the Z direction, completely eliminating conventional mechanical bearing mechanisms such as rolling bearings. be able to.

Next, rotor attitude control will be explained.

As shown in FIGS. 1 to 5, there is a first displacement detection reference surface (targeter 1-) 11 on the side surface of the rotor other than where the teeth are formed, and a bottom surface of the shelf 4C. A second displacement detection reference plane 12 is set.

On the other hand, first displacement detectors 5a and 5b are installed at three locations on the inner circumferential surface of the side surface of the housing so that their directions are perpendicular to each other, and on the housing so as to face the second displacement detection reference surface 12. Second displacement detectors 5C to 5e are disposed on concentric circles at the bottom and spaced apart by 120 degrees.

Therefore, first, the magnetic force between each motor magnetic pole and electromagnet acting on the rotor 4 is balanced. i
t An excitation current is passed through the magnets, output signals are obtained from the displacement detectors 5a to 5e, the rotor 4 is brought into a horizontal state, the origin position is set, and the value of the excitation current at this time is stored in the memory 8 of the electronic control unit 8. -2. That is, each motor magnetic pole 2a to 2d,
The excitation currents of the attraction magnetic poles 5a to 5d and the electromagnets 3a to 3d are inputted from the human power interface 8-3 of the electronic control device 8 and stored in the memory 8-2, and the initial amount of unbalance from the rotation axis is calculated. Use as a value.

Therefore, when an excitation current is applied to the rotational driving coil of the motor magnetic pole, the rotor 4 is rotationally driven and the table is rotated. At this time, a microstep voltage (described in detail later) is applied to the rotational drive coil.

As for the position of the rotor 4, the origin position is memorized in advance, and the displacement amount, that is, the rotation angle is determined by the number of pulses applied to the rotation drive coil of the motor magnetic pole from this position, and the position of the rotor 4 is controlled. I can do it.

Here, if the number of microstep divisions is m, the rotor can be positioned by minute angles every 2π/N-m (rad).

Further, the distance of the rotor 4 in the XY direction is determined by the detection signals from the first displacement detectors 6a and 6b.
The distance and inclination of the rotor 4 in the Z direction can be monitored by the electronic control device 8 based on the detection signals from 6e to 6e.

Note that the number of displacement detectors is not limited to this number;
It can be increased as appropriate. Moreover, this arrangement can also be changed as appropriate.

Furthermore, the rotor can also 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, excitation current is passed through the motor magnetic poles and electromagnets in advance via the drive circuit 9 to bring the rotor 4 into a non-contact state.

Next, in the non-contact state, the detected values from each displacement detector are read into the electronic control unit 8 via the input interface 8-3, and the read values and the reference value of each displacement detector (the reference value air gap value) is compared so that the deviation is zero! The excitation current values of the attraction coils and electromagnets in each motor magnetic pole are adjusted in the drive circuit 9 via the 10 interface 8-4.

By performing feedback control in this manner, smooth attitude control of the rotor can be performed.

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

According to the above embodiment, the case where four motor magnetic poles and electromagnets are arranged concentrically on the circumference has been described, but as shown in FIGS. 6 and 7, three motor magnetic poles and electromagnets are arranged at three It is also possible to arrange them individually. That is, the motor magnetic poles 28-2g and 58-5g are arranged with their center angles 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 divided into upper and lower parts, and one ring-shaped electromagnet 3h may be provided as the electromagnet. In this case, the electromagnet 3h only performs magnetic levitation in the Z direction, and the inclination of the rotor is controlled exclusively by adjusting the excitation flow of the attracting magnetic pole of each motor magnetic pole divided into upper and lower parts.

Next, microstep drive of the rotor will be explained.

Here, the microstep drive is a method in which two-phase currents with a phase difference of 90 degrees are passed through the two windings of the motor magnetic poles to drive the motor as a synchronous motor. For example, the motor rotation drive currents la and Ib A waveform as shown in FIG. 9 is supplied as shown in FIG. Figure 1O is a block diagram of the microstep drive system, in which 41 is a ring counter, 42.43
is ROM, 44.45 is D/A converter, 46.47
is a drive amplifier, and the coils 28 to 31 for rotational driving of the outer motor magnetic pole 5 are connected to the drive amplifiers 46 and 47 and thereafter.

Note that the drive circuit for the attraction coils 26 and 27 is omitted here.

As shown in this figure, when a movement command value is manually input to the ring counter 41, the waveform data stored in the ROM 42.43, that is, the sine and cosine values are read out, and the D
/A converter 44.45
The analog quantity is input to drive amplifiers 46 and 47 and amplified. The waveform is determined by the electrical angle position (which is added to the rotational drive coil 28, 29, 30, 31), and the ratio of the human phase and B phase is determined by the electrical angle position. Move the rotor 4. Note that when a voltage amplifier is used as a drive amplifier, passive damping can be expected. With this configuration, the rotor 4 can move smoothly and can be positioned over a minute distance.

By the way, this rotor sandwich type actuator drives the rotor in a non-contact state, so the mechanical damping of the rotor's movement is very small.Therefore, even when microstep drive is performed, there is some vibration, and this vibration can be suppressed. To suppress it, configure as follows.

As shown in FIGS. 1 and 2, a case will be described in which a total of four motor magnetic pole centers are arranged at concentric positions every 90 degrees.

Here, the phases of the plurality of motor magnetic poles arranged in the rotation direction relative to the teeth of the rotor 4 are shifted by π/4 from each other. That is, at a certain point in time, the inner motor magnetic poles 2a, 2
In the rotation drive coil C, the magnetomotive force shown in FIG. 11(a) is generated, while in the rotation drive coils of the inner motor magnetic poles 2b and 2d, the magnetomotive force is generated as shown in FIG. 11(b). Each motor magnetic pole is arranged so as to generate a magnetomotive force such that

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

When the position of the motor magnetic poles is shifted by π/4 in electrical angle in this way, the rotational torque characteristics are made uniform, and compared to when they are arranged in the same phase, damping becomes larger and smoother driving becomes possible. Become. In other words, it is possible to improve resolution and reduce vibration.

Note that although the case of microstep drive has been described above, in the case of a normal step motor, the pattern is as shown in FIG. 12. That is, motor VAil (motor magnetic pole 2a, 5a or 2c).

5c) is one-phase excitation, motor magnetic pole ■ (motor magnetic pole 2
b, 5b or 2d, 5d) is two-phase excitation, and vice versa.

Here, the plus/minus in the table is the polarity of the coil voltage (or current) during bipolar drive of the step motor.

In this way, damping can be performed by shifting the excitation phase not only during microstep driving but also when using a normal step motor.

Note that, according to the above embodiment, the motor magnetic pole 2b.

The phases of 5b, 2d, and 5d are motor magnetic poles 2a, 5a, and 2c.
, 5c has been described, but conversely, the motor magnetic poles 2a, 5a, 2c.

5c, motor magnets i2b, 5b, 2d, 5d are π/
4 You may be delayed. In this case, it is the same as changing the rotation direction of the rotor. Furthermore, nxg/4 (n
= 1.3, 5.7) The above effects can be achieved even if the speed is set so that the speed is delayed even if the speed is ahead. In other words, when one side is 2-phase excitation, the other side is preferably 1-phase excitation.

Next, an embodiment of position closed loop control of this rotor sandwich type actuator will be described with reference to FIG. 13.

Here, a moving direction position detector is provided. The motor magnetic poles and the moving direction position detector are supported and fixed by the fixed frame. Further, a drive circuit for the attraction coils 26 and 27, a displacement detector, a gap control circuit, and the like are omitted.

In the figure, 51 is a deviation counter that outputs the error between the current position and the movement command value, 52 is a D/A converter, and 53 is a PID.
A controller consisting of an adjuster etc., 54 is a code discriminator,
It outputs a positive or negative signal to advance or delay the phase. 55 is an absolute value circuit, and 5G is a phase output device, which is normally fixed at 90 degrees. 57 is a phase adder/subtractor, and 58.59 is a ROM.

60, (it is a D/A converter, 62.63 is a multiplier,
Reference numerals 64 and 65 are drive amplifiers, and 66 is a moving direction position detector, which detects the phase of the rotor 4 with respect to its teeth. The waveform is
For example, it is output as a sine wave or cosine waveform. 67 is a position converter, for example, an R/D (resolver/digital) converter, which converts the current phase output to the phase adder/subtractor 57.
At the same time, the velocity output is outputted to the summing point 68 to form a velocity loop. Further, the position converter 67 outputs a current position signal to the deviation counter 51 to form a position loop.

With this configuration, it is possible to prevent synchronization that is likely to occur in open loop control.

The structure of the rotor sandwiched actuator of the present invention can be modified in various ways depending on the expected weight and shape of the rotor, the weight of objects placed on the table surface, etc. In particular, the arrangement of the motor magnetic poles and electromagnets and the structure of the rotor can be modified as appropriate.

Furthermore, although the embodiment described above shows an example of a digitally controlled control means, it is also possible to perform conventional PID adjustment using an analog circuit.

Note that the present invention is not limited to the above embodiments,
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, (a) a stator including inner motor magnetic poles, outer motor magnetic poles, and electromagnets arranged coaxially, and (b) the inner motor a cup-shaped rotor disposed between a magnetic pole and an outer motor magnetic pole, and receiving a buoyancy force balanced with its own weight by the electromagnet;
(c) displacement detection means for detecting relative displacement between the stator and the rotor; (d) adjusting a gap between the stator and the rotor based on a detected value from the displacement detection means; Since the rotor is provided with a control means for rotationally driving the rotor in a non-contact state, (1) the rotor can be rotated in a non-contact state, and the control thereof is extremely smooth.

(2) 41st A direct drive type actuator is constructed which has a large torque per weight and is capable of high-speed operation with high precision, and its construction is simple and compact.

(3) Since there is no need to supply electricity to the rotor and the rotor is lightweight, the rotor moves quickly and has high responsiveness.

(4) For driving, the rotor only needs to have a tooth row, and since the rotation drive coil, attraction coil, and electromagnet are provided on the stator side, the heat generated by the coil is due to heat conduction on the stator side. It can be effectively absorbed and does not cause an upper limit on the temperature of the rotor.

(5) No mechanical bearings are required, so no dust is generated.

■Can be used even in vacuum.

■No noise or vibration from the drive source.

■Highly accurate positioning is possible.

■No maintenance such as refueling is required.

As described above, the present invention provides a rotor-pinch type actuator that has various advantages and can be used in harsh environments such as semiconductor factories, biotechnology-related factories, and high vacuum atmospheres such as space factories where dust is particularly important. can be obtained.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway plan view of a rotor-pinch type actuator showing an embodiment of the present invention, and FIG.
3 is an overall configuration diagram of a sandwiched-rotor type actuator showing an embodiment of the present invention, FIG. 4 is a configuration diagram of motor magnetic poles, FIG. 5 is an explanatory diagram of the operation of motor magnetic poles, and FIG. 6 7 is a partially cutaway plan view of a rotor sandwiching type actuator showing another embodiment of the present invention, and FIG. 7 is a diagram showing ■-■ in FIG.
Fig. 8 is a partially cutaway sectional view of a rotor sandwiching type actuator equipped with a ring-shaped electromagnet, Fig. 9 and Fig. 11 are microstep drive current waveform diagrams, Fig. 10
12 is a block diagram of a microstep drive system, FIG. 12 is an excitation sequence diagram, FIG. 13 is a block diagram of a closed loop control system, 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 3.
3a to 3d, 3e to 3g, 3b - Electromagnet 4...Rotor 5, 5a to 5d, 5e to 5g - Outer motor magnetic pole 6a to 6e...Displacement detector 8...Electronic control bag r 9... Drive circuit lO... 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...Fourth magnetic poles 26, 27... Attraction coil

Claims (10)

[Claims] (1) (a) a stator comprising an inner motor magnetic pole, an outer motor magnetic pole, and an electromagnet arranged coaxially; (b) a stator disposed between the inner motor magnetic pole and the outer motor magnetic pole, and the electromagnet (c) displacement detection means for detecting relative displacement between the stator and the rotor; and (d) the fixation based on the detected value from the displacement detection means. What is claimed is: 1. A rotor sandwiching type actuator, comprising control means for adjusting a gap between the child and the rotor and for rotating the rotor in a non-contact state. (2) The motor magnetic pole has a core member having a plurality of pole pieces installed at predetermined intervals, and includes a rotational drive magnetic pole excited by a rotational drive coil wound on the pole piece and the rotational drive. 2. The rotor sandwiching type actuator according to claim 1, further comprising an attraction magnetic pole which is excited by an attraction coil wound on the core member adjacent to the magnetic pole. (3) The rotor according to claim 1, wherein the rotor faces each of the motor magnetic poles and has a ring-shaped row of teeth arranged at a constant pitch, and has a table surface portion. Pincer type actuator. (4) 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 connected to an upper part of the tooth row. The rotor-pinch type actuator described in . (5) The rotor sandwiched actuator according to claim 1, wherein at least three motor magnetic poles are arranged at concentric circumferential positions on the stator. (6) The control means includes a gap control means for adjusting the gap between the stator and the rotor by changing the excitation current of the attraction coil based on the detected value from the displacement detection means, and a gap control means for adjusting the gap between the stator and the rotor; 2. The rotor sandwiching type actuator according to claim 1, further comprising rotational drive control means for rotating the rotor in a non-contact state. (7) The rotational drive control means includes means for supplying sine wave and cosine wave currents to the rotational drive coils and performing microstep drive using the currents flowing through each phase of these rotational drive coils. A rotor sandwiching type actuator according to claim 1. (8) It is characterized by comprising means for detecting displacement of the rotor in the rotational direction by a displacement detecting means during the microstep drive, and performing closed loop control so as to maintain a constant excitation advance angle based on the detected value. A rotor sandwiching type actuator according to claim 7. (9) The rotor sandwiched actuator according to claim 1, wherein the excitation phases between the plurality of motor magnetic poles arranged in the rotational direction of the rotor are shifted by π/4. (10) The displacement detecting means includes means for detecting the states of vertical movement, horizontal movement, and rotation, and controlling the rotor to a preset position by the control means based on the detected values. A rotor sandwiching type actuator according to claim 1.