JP4406357B2 - Magnetic bearing device - Google Patents

Description

  The present invention relates to a magnetic bearing device.

Currently, chemical vapor deposition equipment (CVD) for growing thin films of specified components on semiconductor substrates (wafers)
In a device such as a device, a ball bearing is mainly used as a bearing device for rotating and supporting a rotor.

Such a chemical vapor deposition apparatus requires operation in a depressurized and clean atmosphere. Therefore, in the conventional apparatus constituted by using ball bearings as constituent elements, there is a problem that the lubricating oil of the ball bearings diffuses to foul the thin film formed on the wafer and reduce the product yield. . Further, when rust is generated in the ball bearing, a clean atmosphere is contaminated, and the generated rust causes galling in the bearing, which may make it impossible to rotate the rotor stably. In such a case, the ball bearing needs to be replaced, but it takes a lot of time for the replacement.

Therefore, it has been studied to use a magnetic bearing device instead of using a ball bearing as a component. Since magnetic bearing devices have features such as non-contact, non-lubrication, and long life, various researches and application developments are being promoted in various fields.

A conventional magnetic bearing device is configured, for example, as shown in FIG. This magnetic bearing device 90 is housed in a casing 91 and has a vertical rotor 93 provided with a thrust disk 93a on the lower end side of a rotating shaft 92, and a magnetic pole is opposed to the thrust disk 93a by providing a gap between the upper and lower surfaces. The electromagnet 9 constituting the thrust magnetic bearing 94 for supporting the thrust direction of the rotor 93 in a non-contact manner
4a, 94b. The rotor 93 is supported in a non-contact manner in the radial direction by radial magnetic bearings 95 and 96 provided at the upper and lower portions of the rotating shaft 92, and is driven to rotate around the rotating shaft 92 by an electric motor (motor) 97. The

The radial magnetic bearings 95 and 96 are fixed to the casing 91 at a position opposed to the cylindrical laminated yoke portions 93b and 93c fixed to the rotor 93 in a state of being stacked in the axial direction of the rotary shaft 92. Upper electromagnets 95a, 95b, 95c, 95d (95b, 9d) arranged equally in the circumferential direction
5d is not shown) and lower electromagnets 96a, 96b, 96c, 96d (96b, 96d are not shown).

Further, a displacement sensor (not shown) is provided in the housing 91, and the displacement sensor detects the displacement in the axial direction and the radial direction of the rotor 93. Based on this, a control from a control unit (not shown) is performed. The thrust magnetic bearing 94 and the radial magnetic bearings 95 and 96 are controlled by the signal.

In the conventional magnetic bearing device configured as described above, a thrust magnetic bearing 94, radial bearings 95, 96, a displacement sensor (not shown), and an electric motor 97 are arranged in parallel along the direction of the rotary shaft 92. Therefore, the magnetic bearing device is elongated in the direction of the rotation shaft 92. Further, since the laminated end surfaces of the laminated yoke portions 93b, 93c provided in the rotor 93 are exposed inside the decompressed casing 91, the rotor 93 has a rusted state when the laminated end surfaces are rusted. Rust is scattered by the rotation, and the inside of the casing 91 is contaminated. In particular, in a CVD apparatus, a thin film formed on a wafer may be fouled and the yield of products may be reduced.
JP-A-10-70866 JP-A-53-88443

As described above, in the conventional magnetic bearing device, since the radial magnetic bearings are arranged in a plurality of locations in the axial direction of the rotating shaft, the device is long in the axial direction. Further, there is a possibility that the inside of the housing may be contaminated by rusting of the end face of the laminated yoke exposed in the housing. Accordingly, an object of the present invention is to provide a magnetic bearing device in which the axial length of the rotating shaft is shorter than that of the conventional one and the contamination inside the device can be reduced.

In order to achieve the above object, in the present invention, a rotatable rotor, and the rotor is driven to rotate.
And a rotatable disk having slits formed on both ends of the rotor in the rotation axis direction and slits formed through the outer circumferential surface along a radial direction perpendicular to the rotation axis. A first electromagnet disposed opposite to one end surface of the disk in the direction of the rotation axis, and forming a magnetic flux flowing on the one end surface from the rotation axis side of the disk to the outer peripheral surface side; and the disk A second electromagnet disposed opposite to the other end surface in the direction of the rotation axis and forming a magnetic flux flowing on the other end surface from the outer peripheral surface side of the disk to the rotation shaft side, and the outer periphery of the disk A third electromagnet disposed on the outer peripheral surface and forming a magnetic flux flowing from the one end surface side to the other end surface side, the first electromagnet, the second electromagnet, and the Third electromagnetic
Stone, it was along said rotary shaft are arranged a plurality spaced in a circumferential direction of the rotary axis magnetic bearing apparatus according to claim Rukoto.

Further, in the present invention, a rotatable rotor, and a rotational drive means for rotationally driving the rotor,
A rotatable disk having slits provided in the rotor and having slits formed through both end faces of the rotor in the rotation axis direction and inner circumferential surfaces in a direction orthogonal to the rotation axis; and the rotation direction of the disk A first electromagnet disposed opposite to the one end surface and forming a magnetic flux flowing on the one end surface from the outer peripheral surface side of the disk to the rotating shaft side; and on the other end surface of the disk in the rotating shaft direction. A second electromagnet that forms a magnetic flux that flows from the rotating shaft side of the disk to the outer peripheral surface side, and is disposed opposite to the inner peripheral surface of the disk, and a third electromagnet for forming a magnetic flux flowing in the other end face side from the one end face to the inner peripheral surface, wherein
The first electromagnet, the second electromagnet, and the third electromagnet are arranged along the rotation axis.
And a magnetic bearing apparatus characterized that you have arranged a plurality circumferentially spaced rolling axis.

According to the magnetic bearing device of the present invention configured as described above, the conductivity adjusting means for making the conductivity discontinuous with respect to the rotation direction of the rotor is provided, and the rotor is predetermined by the magnetic attraction force. There are provided a plurality of electromagnets that are supported in a non-contact manner with respect to the axial direction and the direction perpendicular to the axial direction (thrust direction and radial direction). Therefore, the eddy current loss due to the eddy current generated with the rotation of the rotor is weakened in both the thrust direction and the radial direction. Therefore, it is not necessary to configure the apparatus using laminated yokes as in the prior art, and a magnetic bearing apparatus is realized that is short in the direction of the rotation axis and can reduce contamination inside the apparatus.

This realizes a magnetic bearing device that is shorter in the direction of the rotational axis than conventional ones and can reduce contamination inside the device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view according to the first embodiment of the magnetic bearing device of the present invention, and FIG. 2 is a sectional view taken along line AA in FIG.

The rotor 4 in the magnetic bearing device 1 is housed in a substantially cylindrical casing 2, and a disk 4 a is attached near the lower end of the rotating shaft 3. Further, the rotor 4 is placed on the upper and lower surfaces of the disk 4a with respect to the thrust direction (the axial direction of the rotary shaft 3) and the tilt direction (the tilt direction of the rotary shaft 3) of the rotor 4 by facing the magnetic poles through a gap. Upper electromagnets 5a, 5 for non-contact support
b, 5c, 5d and lower electromagnets 5e, 5f, 5g, 5h (however, 5f and 5h are not shown) are provided. These upper electromagnets 5a, 5b, 5c, 5d and lower electromagnet 5e,
Reference numerals 5f, 5g, and 5h constitute a thrust magnetic bearing 5. Further, electromagnets 6a and 6b for supporting the outer surface of the disk 4a of the rotor 4 in a non-contact manner in the radial direction of the rotor 4 (direction perpendicular to the rotation shaft 3) by making the magnetic poles face each other through a gap. , 6c, 6d are provided. These electromagnets 6 a, 6 b, 6 c, 6 d constitute a radial magnetic bearing 6.

An electric motor 7 for rotationally driving the rotor 4 is provided above the upper electromagnets 5a, 5b, 5c, and 5d in the housing 2. A total of 36 slits (conductivity adjusting means) 8 are provided on the outer peripheral side of the disk 4a of the rotor 4 in this example, penetrating in the axial direction of the rotating shaft 3 and formed at equal intervals along the radial direction.

FIG. 3 is a view for explaining the flow of magnetic flux of the thrust magnetic bearing 5 and the radial magnetic bearing 6, and only the upper electromagnet 5 c and the lower electromagnet 5 g of the thrust magnetic bearing 5 and the electromagnet 6 c of the radial magnetic bearing 6 are enlarged. It shows.

The upper electromagnet 5c and lower electromagnet 5g of the thrust magnetic bearing 5 and the electromagnet 6c of the radial magnetic bearing 6 are magnetic paths in a plane substantially parallel to the plane formed by the respective slits 8 provided in the disk 4a of the rotor 4. Will be formed. That is, the magnetic flux M1 of the upper electromagnet 5c of the thrust magnetic bearing 5 flows from the outer side to the inner side with respect to the radial direction of the disk 4a.
c enters the electromagnet yoke through the gap between the disk 4a and constitutes a closed loop. The magnetic flux M2 of the lower electromagnet 5g of the thrust magnetic bearing 5 flows from the inner side to the outer side in the radial direction of the disk 4a, enters the electromagnet yoke through the gap between the lower electromagnet 5g and the disk 4a, and forms a closed loop. ing. Further, the magnetic flux M3 of the electromagnet 6c of the radial magnetic bearing 6 flows from the upper side to the lower side with respect to the axial direction of the disk 4a, enters the electromagnet yoke through the gap between the electromagnet 6c and the disk 4a, and forms a closed loop. Yes. The surfaces formed by these M1, M2, and M3 are slits 8
Is substantially parallel to the surface to be formed.

The upper electromagnets 5a, 5b and 5d and the lower electromagnets 5e, 5f and 5h of the thrust magnetic bearing 5 and the electromagnets 6a, 6b and 6d of the radial magnetic bearing 6 are not shown here.
A magnetic flux flow is formed as in FIG.

Next, the effect | action by providing the slit 8 in the electroconductivity adjustment means in the present invention, ie, disk 4a, is explained. The reason why the slits 8 are provided in the disk 4a in the present invention is to reduce iron loss, particularly eddy current loss, which occurs when the disk 4a of the rotor 4 is rotationally driven by the electric motor 7.

That is, if the state where the slit 8 is not formed is considered, when the disk 4a is rotationally driven by the electric motor 7, the upper electromagnets 5a, 5b, 5c, 5d and the lower electromagnets 5e, 5f, 5g of the thrust magnetic bearing 5 are used. , 5h, and electromagnets 6a, 6b, 6c, 6d of the radial magnetic bearing 6
Eddy current loss occurs on the upper and lower surfaces and the outer peripheral surface facing the magnetic pole portion. This eddy current loss occurs because the magnetic fluxes of the thrust magnetic bearing 5 and the radial magnetic bearing 6 that are divided and arranged in the circumferential direction are not uniformly distributed in the circumferential direction.

In conventional magnetic bearing devices, laminated yokes are widely used to reduce this eddy current loss. However, the eddy current loss reduction method using the laminated yoke works effectively for the radial magnetic bearing, but the effect cannot be expected for the thrust magnetic bearing. Therefore, in the present invention, focusing on the fact that eddy current loss occurs with the rotation of the rotor 4, the disk 4a provided with the slit 8 is rotated, and a radial magnetic bearing and a thrust magnetic bearing are arranged around it.

As the rotor 4 rotates, an eddy current is induced in the disk 4a due to the thrust magnetic bearing 5 and the radial magnetic bearing 6, and this eddy current is blocked by the slit 8 provided in the disk 4a.
This is because the magnetic flux does not move in the circumferential direction of the disk 4a because the slit 8 is formed. Therefore, generation of eddy current can be suppressed.

In the magnetic bearing device 1 of the present embodiment configured as described above, the rotor 4 can be used without using a laminated yoke for reducing eddy current loss by providing the slit 8 which is a conductivity adjusting means.
The thrust magnetic bearing 5 and the radial magnetic bearing 6 can be disposed on the upper and lower portions and the outer peripheral portion of the disk 4a. Therefore, the axial length is shorter and a compact configuration as compared with a conventional magnetic bearing device in which a plurality of radial magnetic bearings are arranged in the axial direction.

Moreover, since it becomes unnecessary to use a laminated yoke, the contamination in the housing | casing by the end surface of the laminated yoke exposed in the housing | casing 2 rusting can be prevented. Further, since unbalance caused by centrifugal force and thermal expansion differential deformation, which is a problem when using a laminated yoke, can be removed or reduced, the rotational motion characteristics of the rotor 4 can be improved, and a large-diameter rotor can be used. It becomes easy.

In FIG. 2, the electric motor 7 is provided above the upper electromagnets 5a, 5b, 5c, 5d of the thrust magnetic bearing 5, but for example, the lower electromagnets 5e, 5f,
The structure provided below 5g and 5h may be sufficient. Further, in FIG. 3, the magnetic fluxes M1 and M of the upper electromagnet 5c and the lower electromagnet 5g of the thrust magnetic bearing 5 and the electromagnet 6c of the radial magnetic bearing 6 are shown.
2 and M3 are described, but the effect of the present invention can be expected even if the electromagnet is controlled so that the flow of magnetic flux is reversed.

Next, a second embodiment of the present invention will be described with reference to FIG. In each embodiment described below, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

FIG. 4 is a sectional side view of the magnetic bearing device 10 according to the second embodiment of the present invention. The magnetic bearing device 10 according to the present embodiment is characterized in that an insertion portion 2a is provided so that the casing 2 can be inserted into the internal space of the rotor 4, and the motor 7 is attached to the insertion portion 2a.
It is in the point arrange | positioned in the inner peripheral part. Therefore, as shown in the figure, the radial magnetic bearing 6 and the electric motor 7 can be arranged at the same height with respect to the axial direction of the rotary shaft 3.

According to the second embodiment having such a configuration, the axial length is shorter than that of the first embodiment, and a compact magnetic bearing device can be provided. Subsequently, a third embodiment of the present invention will be described with reference to FIG. FIG. 5 shows a magnetic bearing device 20 according to the third embodiment of the present invention.
FIG. The magnetic bearing device 20 according to the present embodiment is characterized by the insertion portion 2a of the housing 2.
4 is deformed from that shown in FIG. 4, and the radial magnetic bearing 6 is mounted on the inner peripheral portion of the disk 4 a of the rotor 4 by attaching the radial magnetic bearing 6 to the insertion portion 2 a.
The electric motor 7 is disposed on the outer periphery of the rotor 4. Therefore, as shown in the figure, the radial magnetic bearing 6 and the electric motor 7 can be arranged at the same height with respect to the axial direction of the rotary shaft 3.

According to the third embodiment having such a configuration, the axial length is shortened similarly to the previous embodiment, and a compact magnetic bearing device can be provided. 6 is a side sectional view for explaining the displacement sensor arrangement of the thrust magnetic bearing 5 and the radial magnetic bearing 6 in the magnetic bearing device 1 of the present invention, and FIG. 7 is a sectional view taken along the line BB in FIG. Here, the side sectional view shown in FIG. 6 corresponds to the sectional view taken along the line CC in FIG.

Thrust displacement sensors 11a, 11b, 11c, and 11d used for the thrust magnetic bearing 5 are:
The rotor 4 is fixed to the casing 2 at equal intervals with a gap interposed between the upper surface of the disk 4a. These thrust displacement sensors 11a, 11b, 11c, and 11d detect the upper surface (the portion where the slit 8 is not formed) near the inner periphery of the disk 4a, and the shaft of the rotor 4 by a thrust displacement sensor converter and a signal processing circuit (not shown). The direction displacement and the tilt direction displacement are obtained. Based on the displacement signals of the thrust displacement sensors 11a, 11b, 11c, and 11d, the positioning of the thrust magnetic bearing 5 is controlled by a control signal from a control unit (not shown).

Further, the radial displacement sensors 12a and 12b used for the radial magnetic bearing 6 are fixed to the housing 2 with a phase difference of 90 ° in a state where a gap is provided on the outer surface of the rotor 4 above the disk 4a. . These radial displacement sensors 12a and 12b detect the outer peripheral surface of the rotor 4 and determine the radial displacement of the rotor 4 by a radial displacement sensor converter and a signal processing circuit (not shown). Based on the displacement signals of these radial displacement sensors 12a and 12b, the positioning of the radial magnetic bearing 6 is controlled by a control signal from a control unit (not shown).

In FIG. 6, the thrust displacement sensors 11a, 11b, 11c, and 11d are the rotor 4
Although it is being fixed to the housing | casing 2 in the state via a space | gap with respect to the upper surface of the disk 4a, you may fix to the housing | casing 2 in the state via the space | gap on the lower surface of the disk 4a. Further, the radial displacement sensors 12a, 1
2b is fixed to the housing 2 with a gap with respect to the outer peripheral surface of the rotor 4 at the upper part of the disk 4a, but the outer peripheral surface of the rotor 4 or the inner peripheral surface of the rotor 4 at the lower part of the disk 4a. On the other hand, it may be fixed to the housing 2 through a gap.

In this example, the number of thrust displacement sensors is four and the number of radial displacement sensors is two. However, the number of thrust displacement sensors is three or more, and the number of radial displacement sensors is two or more. Thus, it is possible to reliably detect the five degrees of freedom required for the device.

8 is a side sectional view for explaining the displacement sensor arrangement of the thrust magnetic bearing 5 and the radial magnetic bearing 6 in the magnetic bearing device 30 of the present invention, and FIG. 9 is a sectional view taken along the line DD in FIG.
Here, the side sectional view shown in FIG. 8 corresponds to the sectional view taken along line EE in FIG.

Thrust displacement sensors 13a, 13b, 13c, 13d, 1 used for the thrust magnetic bearing 5
3e, 13f, 13g, 13h (however, 13e, 13f, 13h are not shown)
The disc 4a is fixed to the housing 2 at equal intervals with a gap between the upper surface and the lower surface of the disc 4a. These thrust displacement sensors 13a, 13b, 13c, 13d, 13e, 13f, 13
g and 13h detect the upper surface (the portion where the slit 8 is formed) of the disk 4a, and obtain the axial displacement and the tilt displacement of the rotor 4 by a thrust displacement sensor converter and a signal processing circuit (not shown). These thrust displacement sensors 13a, 13b, 13c, 13d, 13
Based on the displacement signals e, 13f, 13g, and 13h, the thrust magnetic bearing 5 is controlled by a control signal from a control unit (not shown).

Further, radial displacement sensors 14a, 14b, 14c, 14 used for the radial magnetic bearing 6 are used.
d is a case 2 having a phase difference of 90 ° with a gap between the outer peripheral side surface of the disk 4a and a gap.
It is fixed to. These displacement sensors 14a, 14b, 14c, and 14d detect the outer peripheral side surface of the disk 4a, and obtain the radial displacement of the rotor 4 by a radial displacement sensor converter and a signal processing circuit (not shown). These radial displacement sensors 14a, 14b, 14c, 14
Based on the displacement signal of d, positioning of the radial magnetic bearing 6 is controlled by a control signal from a control unit (not shown).

8 and 9, the thrust displacement sensors 13a, 13b, 13c, 13d, 13
e, 13f, 13g, and 13h are fixed to the housing 2 through a gap on the upper and lower surfaces of the disk 4a of the rotor 4, but at least 3 so as to form the same plane on the upper and lower surfaces of the disk 4a. More than one set of thrust displacement sensors may be arranged.

10 shows radial displacement sensors 14a, 14 of the magnetic bearing device 30 shown in FIGS.
It is a figure for demonstrating the differential output signal of c. When the rotor 4 is driven to rotate, the output signals of the radial displacement sensors 14a and 14c are the vibration waveforms 31a and 32a of the rotation synchronization component, and the rotor 4
The output waveforms 31 and 32 are superimposed with the pulsed vibration waveforms 31b and 32b generated each time the slit 8 provided in the disk 4a passes the detection position of the radial displacement sensors 14a and 14c. These pulse-like vibration waveforms 31 b and 32 b are error signals generated due to the influence of the slit 8 regardless of the vibration displacement of the rotor 4.

Therefore, the output signal 31 of the radial displacement sensor 14a or the radial displacement sensor 14c
When the radial magnetic bearing 6 is controlled to fly using the output signal 32, vibration due to the pulsed vibration waveform 31b or 32b is generated as the rotor 4 rotates, and the flying characteristics of the rotor 4 deteriorate. Therefore, by using the differential signal 33 of both the output signals 31 and 32 for the levitation control, the pulse-like vibration waveforms 31b and 32b generated by the influence of the slit 8 can be removed or reduced, and the favorable levitation characteristics are obtained. Is maintained.

Furthermore, the detection error due to the centrifugal force and thermal expansion deformation of the disk 4a can be reduced, and the detection sensitivity of the radial displacement sensor is improved by a factor of 2, so that a magnetic bearing device with higher accuracy and higher stability can be obtained. Provided.

FIG. 10 is a diagram for explaining the differential signals of the radial displacement sensors 14a and 14c. The radial displacement sensors 14b and 14d and the thrust displacement sensors 13a and 13e,
It is also possible to generate a differential signal in the same manner as a set of 3b and 13f, 13c and 13g, and 13d and 13h, and to control the radial magnetic bearing 6 and the thrust magnetic bearing 5 using these differential signals.

In the description of the present embodiment, the number of slits 8 is set to 36, but the present invention is not limited to this number. When the number of the slits 8 is increased, the iron loss caused by the rotation of the rotor 4, particularly the eddy current loss, is reduced, so that the rotation characteristics are improved. However, the mechanical strength of the disk 4a of the rotor 4 is reduced. Accordingly, the number and interval of the slits 8 are determined optimally depending on the capacity of the motor 7, the allowable heat generation amount of the rotor 4, the mechanical strength of the disk 4a, the rotational speed, the shape of the slit 8, and the like, and are arbitrarily determined in actual design. Is. In the present invention, the effect more than the conventional one can be obtained by simply providing one slit.

In each of the above embodiments, only the example in which the slit 8 is formed on the disk 4a is shown. However, the rotor and the disk may be integrally formed, and the slit may be formed there. In this case, the conductivity adjusting means is only the slit.

Moreover, in each said embodiment, although the slit showed only what was formed in the state along a radial direction and a thrust direction, this invention expects an effect also when a slit is formed in directions other than this. Can do. That is, in the present invention, it is necessary to prevent the eddy current generated on the surface of the disk 4a from moving in the rotational direction. For example, even if the slit is formed in a slightly inclined state (spiral shape) from the rotor radial direction. This can contribute to reduction of eddy current. That is, the slit forming angle can be arbitrarily set according to the design.

In each of the above embodiments, only the example in which the conductivity adjusting means is configured by forming a slit in the disk 4a is shown. However, a plurality of members formed in a plate shape are arranged around the rotor at predetermined intervals. Even if it joins and it forms in a disk shape as a whole, the effect of the present invention can be expected.

1 is a side sectional view according to a first embodiment of a magnetic bearing device of the present invention. FIG. 2 is a sectional view taken along line AA in FIG. 1. The figure for demonstrating the flow of the magnetic flux of a thrust magnetic bearing and a radial magnetic bearing. The sectional side view of the magnetic bearing apparatus which concerns on the 2nd Embodiment of this invention. The sectional side view of the magnetic bearing apparatus which concerns on the 3rd Embodiment of this invention. The sectional side view explaining displacement sensor arrangement of a thrust magnetic bearing and a radial magnetic bearing in a magnetic bearing device. BB sectional drawing in FIG. The sectional side view explaining the other example of the displacement sensor arrangement | positioning of the thrust magnetic bearing in a magnetic bearing apparatus, and a radial magnetic bearing. The DD sectional view taken on the line in FIG. The figure for demonstrating the differential output signal of radial displacement sensor 14a, 14c of the magnetic bearing apparatus 30 shown in FIG. 8 and FIG. The sectional side view which shows the conventional magnetic bearing apparatus.

DESCRIPTION OF SYMBOLS 1,10,120,30,40 ... Magnetic bearing apparatus 2 ... Housing 3 ... Rotary shaft 4 ... Rotor 4a ... Disk 5 ... Thrust magnetic bearing 6 ... Radial magnetic bearing 7 ... Electric motor 8 ... Slit (Conductivity adjusting means)

Claims (3)

A rotatable rotor;
Rotation driving means for rotating the rotor;
Provided on the rotor and orthogonal to both end surfaces of the rotor in the rotation axis direction and the rotation axis
A rotatable disk having a slit formed through the outer peripheral surface along the radial direction ;
A first electromagnet disposed opposite to one end surface of the disk in the direction of the rotation axis, and forming a magnetic flux flowing on the one end surface from the rotation axis side of the disk to the outer peripheral surface side;
A second electromagnet disposed opposite to the other end surface of the disk in the direction of the rotation axis, and forming a magnetic flux flowing from the outer peripheral surface side of the disk to the rotation axis side on the other end surface;
A third electromagnet disposed opposite to the outer peripheral surface of the disk and forming a magnetic flux flowing from the one end surface side to the other end surface side on the outer peripheral surface;
Equipped with a,
The first electromagnet, the second electromagnet, and the third electromagnet are arranged along the rotation axis.
Magnetic bearing device characterized that you have arranged a plurality spaced in a circumferential direction of the rotary shaft. The rotor has an internal space;
The rotation drive means is the internal space , and is the same as the disk with respect to the axial direction of the rotation shaft.
2. The magnetic bearing device according to claim 1, wherein the magnetic bearing device is inserted at a position at the same height . A rotatable rotor;
Rotation driving means for rotating the rotor;
A rotatable disk having slits provided in the rotor and formed so as to penetrate through both end surfaces of the rotor in the rotation axis direction and inner circumferential surfaces in a direction perpendicular to the rotation axis;
A first electromagnet disposed opposite to one end surface of the disk in the direction of the rotation axis, and forming a magnetic flux flowing from the outer peripheral surface side of the disk to the rotation axis side on the one end surface;
A second electromagnet disposed opposite to the other end surface of the disk in the direction of the rotation axis, and forming a magnetic flux flowing from the rotation axis side of the disk to the outer peripheral surface side on the other end surface;
A third electromagnet disposed opposite to the inner peripheral surface of the disk and forming a magnetic flux flowing from the one end surface side to the other end surface side on the inner peripheral surface;
With
The first electromagnet, the second electromagnet, and the third electromagnet are arranged along the rotation axis.
Magnetic bearing device characterized that you have arranged a plurality spaced in a circumferential direction of the rotary shaft.

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