JPH0979257A - Magnetic bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase rigidity by arranging paired magnets displaced in an axial direction of a rotary shaft in a different level in a position where the fellow paired magnets are repulsed to each other in the diametric direction of the rotary shaft. SOLUTION: Paired magnets 6, 6 are arranged to be displaced in an axial direction of a rotary shaft 1 in a different level in a position where the fellow paired magnets 6, 6 are repulsed to each other in the diametric direction of the rotary shaft 1. Consequently, repulsive force itself of the fellow paired magnets 6, 6 serves as restoration force for returning diametric direction displacement of the rotary shaft 1 back to the origin, so that rigidity in a rotary shaft diametric direction in a side of the other end 1b of the rotary shaft is improved, vibration of the rotary shaft 1 by disturbance can be converged in a short time, and displacement of the rotary shaft 1 generated by disturbance can be lessened. By improving diametric direction rigidity in the side of the other end 1b of the rotary shaft, even in the case of horizontally setting a device total unit, displacement of the rotary shaft 1 by self-weight can be suppressed, and the rotary shaft 1 can be horizontally supported.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a radial direction 2 of a rotary shaft.
The present invention relates to a so-called three-axis control type magnetic bearing device in which a rotating shaft is supported by magnetic force based on an axis line (XY axis line) and its one axial direction (Z axis line), and its rigidity is particularly strengthened.

[0002]

2. Description of the Related Art A three-axis control type magnetic bearing device has first and second magnetic supporting means A and B as shown in FIG. 7, and the first magnetic supporting means A is one end 1a of a rotary shaft 1. On the side, the second magnetic support means B is disposed on the other end 1b side of the rotary shaft 1.

The first magnetic supporting means A comprises a radial magnetic bearing portion 2, and the radial magnetic bearing portion 2 is provided with a plurality of radial electromagnets 200, 200 arranged on the outer peripheral surface side of the rotary shaft 1.
... and radial sensors 201, 201 ..., The radial electromagnets 200, 200 ... Are located on the X-axis and Y-axis in the radial direction of the rotation axis, and are installed opposite to each other via the rotation axis 1, and the radial sensor 201. , 201 ... Detects the displacement of the rotary shaft 1 on the XY axes.

The radial magnetic bearing portion 2 (first magnetic support means A) as described above has the radial sensors 201, 201 ...
The exciting current of the radial electromagnets 200, 200 ... Is adjusted on the basis of the detected value at 1, so that the rotary shaft 1 is supported by the magnetic force in the radial direction with respect to the XY axis.

The second magnetic support means B is composed of a disk 3, an axial sensor 4, an axial electromagnet 5 and a magnet pair 6, the disk 3 is integrally attached to the rotary shaft 1, and the axial sensor 4 is the Z axis. The displacement of the rotary shaft 1 on the line is detected, and the axial electromagnet 5 is configured to attract the disk 3 from the one surface 3a side based on the detection value of the axial sensor 4.

The magnet pair 6 is composed of a rotating side permanent magnet body 600 and a fixed side permanent magnet body 601. The rotating side permanent magnet body 600 is embedded on the other surface 3b side of the disk 3 and also fixed side permanent magnet body. 601 is embedded in the bearing housing portion 7, and both permanent magnet bodies 600 and 601 are configured to face each other and attract each other, thereby attracting the disk 3 from the other surface 3b side.

The second magnetic support means B as described above supports the rotary shaft 1 in the axial direction (on the Z-axis) by the balance of the attraction forces of the axial electromagnet 5 and the magnet pairs 6, 6, and the rotary shaft 1 is When displaced in the radial direction, the radial displacement is restored by the centripetal force of the magnetic coupling between the rotating permanent magnet body 600 and the stationary permanent magnet body 601, that is, the function as a thrust bearing and the function as a radial bearing are provided. .

[0008]

However, in the conventional magnetic bearing device as described above, the other end 1b of the rotary shaft is used.
On the side, as shown in FIG. 8, the restoring force that restores the radial displacement of the rotary shaft 1 to the original state is the edge portion 60 of the permanent magnet bodies 600 and 601.
Horizontal component force F _X of suction force F acting near 0a and 601a
Therefore, since the restoring force is insufficient, the rigidity in the radial direction of the rotating shaft is low, and the vibration of the rotating shaft 1 due to disturbance does not converge for a long time.
It takes time for the vibration to stabilize.

Further, in the conventional device, since the radial rigidity on the side of the other end 1b of the rotating shaft is low as described above, when the entire device is installed horizontally, the displacement of the rotating shaft 1 due to its own weight cannot be suppressed. However, there is a problem that the rotating shaft 1 cannot be supported horizontally.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a magnetic bearing device having enhanced rigidity.

[0011]

In order to achieve the above object, the invention according to claim 1 has a first magnetic support means arranged on one end side of a rotary shaft and on the other end side of the rotary shaft. And a second magnetic support means disposed, wherein the first magnetic support means is a radial magnetic bearing portion that magnetically supports the rotating shaft in a radial direction, and the second magnetic support means is the above-mentioned A disk integrally provided on the rotating shaft, an axial sensor for detecting the axial displacement of the rotating shaft, an axial electromagnet that attracts the disk from one side based on the detection value of the axial sensor, and the disk A plurality of magnets that are composed of a mounted rotating-side permanent magnet body and a fixed-side permanent magnet body that attracts each other between the rotating-side permanent magnet body, and that attracts the disk from the other surface side by its attraction force. Magnetic bearing consisting of a pair In location, the magnet pair each other is in a position repel in the radial direction of the rotary shaft, characterized in that arranged staggered by shifting the magnet pair in the axial direction of the rotating shaft.

The invention according to claim 2 is characterized in that the stepwise arrangement of the magnet pairs is stepwise.

The invention according to claim 3 is characterized in that the stepped arrangement shape of the magnet pair is uneven.

According to a fourth aspect of the present invention, there is provided a first magnetic support means arranged on one end side of the rotary shaft and a second magnetic support means arranged on the other end side of the rotary shaft. The first magnetic support means is composed of a radial magnetic bearing portion that magnetically supports the rotary shaft in the radial direction, and the second magnetic support means is integrated with the rotary shaft along the axial direction of the rotary shaft. A plurality of discs provided, an axial sensor that detects the axial displacement of the rotary shaft, an axial electromagnet that attracts the disc based on the detection value of the axial sensor, and a fixed side that is interposed between the discs. It is characterized in that it comprises a permanent magnet body and a rotating side permanent magnet body that is attached to each of the disks and attracts each other between the fixed side permanent magnet body.

According to the first to third aspects of the present invention, when the rotating shaft is displaced in the radial direction due to disturbance or the like, the displacement is restored at the other end of the rotating shaft due to the repulsive force between the magnet pairs. At this time, since the direction of the repulsive force is the radial direction of the rotating shaft, the repulsive force itself is not a horizontal component force or a vertical component force of such a repulsive force but a restoring force for restoring the radial displacement.

According to the fourth aspect of the invention, when the rotary shaft is displaced in the radial direction, the radial displacement of the rotary shaft is doubled at the other end of the rotary shaft so as to be double above and below the fixed permanent magnet body. The resilience of occurs.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a magnetic bearing device according to the present invention will be described in detail below with reference to FIGS.

In the structure of the magnetic bearing device, the first magnetic support means A is provided on the rotary shaft one end 1a side, and the rotary shaft other end 1a is provided.
The second magnetic support means B is provided on the b side, and the first magnetic support means A is composed of a radial magnetic bearing portion 2 which supports the rotating shaft 1 by magnetic force in the radial direction, and The magnetic supporting means B comprises a disk 3, an axial sensor 4, an axial electromagnet 5 and a magnet pair 6, the disk 3 is integrally provided on the rotary shaft 1, and the axial sensor 4 detects displacement of the rotary shaft 1 on the Z axis. Detect and axial electromagnet 5
Is sucking the disk 3 from the one surface 3a side based on the detection value of the axial sensor 4, as in the conventional example.
The same members as those are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 1, this magnetic bearing device has two pairs of ring-shaped magnets 6, and each of these magnet pairs 6, 6 has a rotating side permanent magnet body 600 and a fixed side permanent magnet body 601.
It is composed of

The rotating side permanent magnet body 600 is mounted on the other surface 3b side of the disk 3, and the fixed side permanent magnet body 601 is mounted on the bearing housing portion 7.
00 and 601 are arranged to face each other and attract each other, and the attraction force attracts the disk 3 from the other surface 3b side.

As shown in FIG. 2, the two pairs of magnets 6 and 6 are arranged in a staggered manner with respect to each other in the axial direction of the rotary shaft 1 and have the same poles (S pole and S pole) side by side. It is provided to fit. That is, the two pairs of magnets 6, 6 are configured such that they repel each other in the radial direction of the rotating shaft 1.

Next, the operation of the magnetic bearing device configured as described above will be described with reference to FIG.

According to this magnetic bearing device, when the operation is started, the radial sensors 201, 201 ... Detect the radial displacement of the rotary shaft 1 on the XY axes, and based on the detected values, the radial electromagnets 200, 200 ... The exciting current is adjusted so that the rotary shaft 1 is supported by the magnetic force in the radial direction with respect to the XY axes.

Further, the axial sensor 4 detects the axial displacement of the rotary shaft 1 on the Z axis, and the axial electromagnet 5 attracts the disk 3 from the one surface 3a side based on the detected value, and at this time, the rotary side. An attractive force acts between the permanent magnet body 600 and the fixed permanent magnet body 601, whereby the disk 3 is attracted from the other surface 3b side, and by such a balance of the attractive force of the axial electromagnet 5 and the magnet pair 6,6. The rotating shaft 1 is supported in the axial direction (on the Z axis).

At this time, on the other end 1b side of the rotary shaft 1, the magnet pairs 6, 6 repel each other in the radial direction of the rotary shaft 1, and the repulsive force itself restores the radial displacement of the rotary shaft 1. It will be a resilience for.

That is, when the rotating shaft 1 is displaced in the radial direction due to a disturbance or the like, the displacement returns to the original state on the other end 1b side of the rotating shaft due to the repulsive force between the magnet pairs 6, 6. At this time, since the direction of the repulsive force is the radial direction of the rotating shaft 1, the repulsive force itself is not the horizontal component force or the vertical component force of the repulsive force, but the restoring force for restoring the radial displacement. .

In the apparatus of this embodiment, the magnet pairs 6, 6 are displaced in the axial direction of the rotary shaft 1 and are arranged at different positions at positions where the magnet pairs 6, 6 repel each other in the radial direction of the rotary shaft 1. Is. For this reason, the repulsive force itself between the magnet pairs 6, 6 becomes a restoring force for restoring the radial displacement of the rotary shaft 1, and the rigidity in the rotary shaft radial direction at the other end 1b of the rotary shaft is improved. It is possible to converge the vibration of the rotating shaft 1 due to the disturbance in a short time and reduce the displacement of the rotating shaft 1 caused by the disturbance.

Further, since the apparatus of this embodiment is intended to improve the radial rigidity on the side of the other end 1b of the rotary shaft as described above, even when the entire apparatus is installed horizontally, the rotary shaft 1 The displacement due to its own weight can be suppressed, and the rotating shaft 1 can be supported horizontally.

In the above embodiment, the magnet pairs 6, 6 are 2
Although the example of the set has been described, the number of sets may be three or more. In this case, as shown in FIG. 3, three or more pairs of magnets 6, 6 ... Are staggered in the axial direction of the rotary shaft 1 and provided in different stages, whereby the magnet pairs 6, 6 ... Rotate with respect to each other. It is configured so as to repel each other in the axial radial direction, that is, the stepwise arrangement of the magnet pairs is changed, or FIG.
As shown in FIG. 3, three or more pairs of magnets 6, 6, ... Are provided in a staggered manner in the axial direction of the rotary shaft 1 in different steps, whereby the magnet pairs 6, 6 ... Repel each other in the radial direction of the rotary shaft. That is, the stepwise arrangement of the magnet pairs is made uneven.

FIG. 5 shows another embodiment of the present invention. In the structure of the magnetic bearing device shown in FIG. 5, the first magnetic support means A is provided on the rotary shaft one end 1a side, and the rotary shaft other end 1 is provided.
The second magnetic support means B is provided on the b side, and the first magnetic support means A is composed of a radial magnetic bearing portion 2 that supports the rotating shaft 1 by a magnetic force in the radial direction, as in the above embodiment. Therefore, detailed description thereof will be omitted.

In this magnetic bearing device, the second magnetic support means B is provided with two disks 3 and 3, and these disks 3 and 3 are arranged vertically along the axial direction of the rotary shaft 1 and 1 is attached integrally.

Fixed permanent magnet bodies 601 and 601 are interposed between the pair of upper and lower disks 3 and 3 as described above.
The fixed side permanent magnet bodies 601 and 601 are the bearing housing portion 7.
It is provided integrally with.

A rotating-side permanent magnet body 6 is provided on each disk 3, 3.
00 and 600 are mounted, and the rotating permanent magnet body 60
0 and 600 are permanent magnet bodies 60 on the fixed side of both disks 3 and 3.
1 and 601 are configured to attract each other.

In this embodiment as well, the second magnetic support means B includes the two disks 3, 3 and the permanent magnet bodies 600, 60.
1, an axial sensor 4 and an axial electromagnet 5 are provided, but since these configurations are similar to those of the above-described embodiment, detailed description thereof will be omitted.

This magnetic bearing device has a fixed permanent magnet body 6
The rotary permanent magnets 600, 600 attracting with the fixed permanent magnet body are arranged above and below 01, 601 respectively. Therefore, when the rotary shaft 1 is displaced in the radial direction, the restoring force for returning the radial displacement of the rotary shaft 1 to the original state is doubled on the upper and lower sides of the fixed permanent magnet bodies 601 and 601 on the other end side 1a of the rotary shaft. Therefore, the rigidity in the radial direction of the rotating shaft on the other end 1b side of the rotating shaft can be improved.

Also in this magnetic bearing device, since the radial rigidity on the side of the other end 1b of the rotary shaft can be improved as described above, even when the whole device is installed horizontally, the weight of the rotary shaft 1 is reduced by its own weight. The displacement can be suppressed, and the rotating shaft 1 can be supported horizontally.

In the above embodiment, an example having two disks 3 and 3 has been described, but the number of disks is as shown in FIG.
It may be three or more as shown in FIG. When the number of discs is increased in this way, the rotating side permanent magnet body is also attached to the increased number of discs, and the fixed side permanent magnet body is provided between the discs newly generated due to the increase of the discs. Install.

Although this embodiment describes a three-axis control type magnetic bearing, this technique can also be used for one-axis control and five-axis control.

[0039]

According to the invention described in claims 1 to 3, the magnet pairs are arranged in a staggered manner at the positions where the magnet pairs repel each other in the radial direction of the rotation shaft. It was done. For this reason, the repulsive force between the magnet pair itself becomes the restoring force to restore the radial displacement of the rotating shaft, and the rigidity in the rotating shaft radial direction at the other end of the rotating shaft is improved, and the rotating shaft due to external disturbances is improved. Can be converged in a short time, and the displacement of the rotating shaft 1 caused by disturbance can be reduced.

Further, according to the present invention, since the radial rigidity on the other end side of the rotary shaft is improved as described above,
Even if this type of magnetic bearing device is installed horizontally,
Displacement of the rotating shaft due to its own weight can be suppressed, and the rotating shaft can be supported horizontally.

According to a fourth aspect of the present invention, rotating permanent magnets that attract each other with the fixed permanent magnet body are arranged above and below the fixed permanent magnet body. Therefore, when the rotary shaft is displaced in the radial direction, a restoring force for returning the radial displacement of the rotary shaft to the original is doubled on the upper and lower sides of the fixed permanent magnet body on the other end side of the rotary shaft. Similar to the above, the rigidity in the radial direction of the rotary shaft on the other end side of the rotary shaft can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

2 is an enlarged view of the embodiment apparatus shown in FIG. 1. FIG.

FIG. 3 is a sectional view showing a main part of another embodiment of the present invention.

FIG. 4 is a sectional view showing a main part of another embodiment of the present invention.

FIG. 5 is a sectional view showing a main part of another embodiment of the present invention.

FIG. 6 is a cross-sectional view showing the main parts of another embodiment of the present invention.

FIG. 7 is a sectional view of a conventional magnetic bearing device.

FIG. 8 is an operation explanatory view of a conventional magnetic bearing device.

[Explanation of symbols]

 A 1st magnetic support means B 2nd magnetic support means 2 Radial magnetic bearing part 3 Disk 4 Axial sensor 5 Axial electromagnet 6 Magnet pair 600 Rotation side permanent magnet body 601 Fixed side permanent magnet body

Claims (4)

[Claims] 1. A first magnetic support means disposed on one end side of the rotary shaft and a second magnetic support means disposed on the other end side of the rotary shaft, wherein the first magnetic support means is provided. The supporting means is composed of a radial magnetic bearing portion that supports the rotating shaft by a magnetic force in the radial direction, and the second magnetic supporting means detects a disc integrally provided on the rotating shaft and an axial displacement of the rotating shaft. Between the axial sensor, the axial electromagnet that attracts the disc from one side based on the detection value of the axial sensor, the rotating permanent magnet body mounted on the disc, and the rotating permanent magnet body. And a plurality of magnet pairs that attract the disk from the other surface side by its attraction force. Radial repulsion A magnetic bearing device, wherein the pair of magnets are arranged in a staggered manner so as to be displaced in the axial direction of the rotating shaft at matching positions. 2. The magnetic bearing device according to claim 1, wherein the staggered arrangement shape of the pair of magnets is stepwise. 3. The magnetic bearing device according to claim 1, wherein the stepwise arrangement shape of the magnet pair is uneven. 4. A first magnetic support means disposed on one end side of the rotary shaft and a second magnetic support means disposed on the other end side of the rotary shaft, wherein the first magnetic support means is provided. The supporting means is composed of a radial magnetic bearing portion that magnetically supports the rotating shaft in the radial direction, and the second magnetic supporting means has a plurality of disks integrally provided on the rotating shaft along the axial direction of the rotating shaft. An axial sensor that detects the axial displacement of the rotary shaft, an axial electromagnet that attracts the disk based on the detection value of the axial sensor, and a fixed permanent magnet body that is interposed between the disks. A magnetic bearing device comprising: a rotary permanent magnet body that is attached to each of the disks and that attracts the fixed permanent magnet body to each other.