JPS61274119A - Rotary shaft supporting method and device thereof - Google Patents

Abstract

PURPOSE:To secure such a bearing as being low in friction torque and usable at every temperature, by attaching a magnetized disc to a part of a shaft rotating at high speed, while setting up an electromagnet, making a disc floatingly supportable, in this magnetized disc. CONSTITUTION:A disc body 12 is being attached to a rotary shaft 11, and this disc body 12 is magnetized in an axial direction. On the other hand, electromagnets 18 and 19 having magnetism in homopolarity as that of a surface part of the disc body are oppositely set up on an outer circumferential surface and on the side of the disc body 12. When a current is made to flow in these electromagnets 18 and 19, magnetic force of these electromagnets 18 and 19 and that of the disc body 12 are repelled to each other whereby the rotary shaft 11 is floatingly supported in bot radial and thrust directions. When the center of the rotary shaft 11 becomes one-sided, pulse width in a pulse current is varied to some extent, and when the magnetic force of these electromagnets 18 and 19 is varied, the center of the rotary shaft 11 is made restorable to the original position.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a rotating shaft support method and apparatus.

[Conventional technology]

Gas bearings are conventionally known as means for supporting a rotating shaft without contacting it. Gas bearings have many advantages, such as low friction torque, smooth rotation, can be used at high and low temperatures, no risk of oil contamination, and because they do not use lubricating oil, there is no problem of lubricating oil deterioration. Although it has advantages, it requires relatively large auxiliary equipment such as a gas compressor, and it has poor responsiveness when performing corrective control when a deviation occurs in the rotation axis due to load fluctuations, etc. It has the following drawbacks.

[Problem that the invention seeks to solve]

The present invention was made to solve the problems of ironwork, and its purpose is to inherit all the advantages of gas bearings, to be able to accurately and quickly control the position of the rotating shaft, and to be extremely compact. It is an object of the present invention to provide a rotary shaft supporting method and device which have many advantages such as being able to be configured as follows.

[Means for solving problems]

In order to achieve the above object, the method according to the present invention magnetizes a part of a rotatably supported shaft rotating at high speed or a disk attached to the shaft in the axial direction or radial direction, and It is characterized in that electromagnets are provided that face each other and apply a repulsive force to the electromagnets, thereby holding the rotating shaft or disk body at a desired position.

In that case, in order to facilitate control, it is recommended that the current supplied to the electromagnet be a pulsed current.

It is also recommended that the electromagnet be energized only when abnormal displacement of the shaft or disc body is detected.

Furthermore, the apparatus according to the present invention for carrying out the above method includes a rotary shaft to be supported magnetized in the axial direction or radial direction or a disc body attached thereto, and a radiation-conforming shape around the rotary shaft so as to fit therein. It is characterized by consisting of a plurality of electromagnets arranged in.

In the above device, the shaft or disk body is magnetized in the axial direction,
It is possible to arrange the electromagnet so that its repulsive force acts in the axial direction, or in such a way that the repulsive force acts in the radial direction.

Alternatively, the shaft or disk body may be magnetized in the radial direction, and the electromagnets may be arranged so that the repulsive force acts in the axial direction, or the electromagnets may be arranged so that the repulsive force acts in the radial direction. It is.

When the repulsive force of the electromagnet acts in the axial direction, a so-called thrust hair ring is formed, and when the repulsive force acts in the radial direction, a so-called radial bearing is formed.

[For production]

With the above configuration, the rotating shaft is supported without contact by receiving the repulsive force of the electromagnet at its magnetized portion or the magnetized portion of the disc attached to the shaft, and the current to the electromagnet is controlled. By doing so, the position of the rotating shaft can be easily changed, resulting in low friction torque and smooth rotation.
It has the following advantages: it can be used at high and low temperatures, there is no oil contamination, there is no problem with lubricating oil deterioration, the position of the rotating shaft can be controlled accurately and quickly, and it can be configured extremely compactly. A shaft support method and apparatus is provided.

〔Example〕

Hereinafter, details of the present invention will be specifically explained with reference to the drawings.

FIG. 1 is an axis-perpendicular sectional view showing an embodiment of a device for implementing the rotating shaft support method according to the present invention, and FIG. 2 is an embodiment of a circuit for operating the device shown in FIG. FIGS. 3 and 4 are block diagrams showing different examples of pulsed currents for controlling the above device, and FIGS.
The figure is a sectional view along the axial direction showing another embodiment of the apparatus for carrying out the rotating shaft supporting method according to the present invention, and FIGS. 6 to 8 show the carrying out the rotating shaft supporting method according to the present invention. FIG. 4 is an explanatory diagram showing the magnetization direction of a disc body and the different arrangement of electromagnets therewith in a device for doing so.

In FIG. 1, 1 is a rotating shaft whose whole or a predetermined thickness from its surface is entirely or partially made of magnetic material in the axial direction, and the magnetic material is magnetized in the axial direction, and 2 is the rotating shaft. Eight magnetic poles 2a or 2 are arranged around a part of the shaft in a dispersion-like manner.
3a to 3h are electromagnetic coils that excite each of the magnetic poles; 4a to 4h are magnetoresistive elements arranged in a dispersion-like manner between each of the magnetic poles facing the rotating shaft 1; It is an axial displacement detector.

Furthermore, in FIG. 2 showing an embodiment of a circuit for operating the above device, the same reference numerals as in FIG. 1 indicate the same components as in FIG. 6a to 6d are switching elements, 7a to 7d are amplifiers that amplify the outputs of the rotational shaft displacement detectors 4a to 4d, 8 is a reference voltage generator, and 9a to 9d are comparisons. vessel, 10a to 10
d is a pulse oscillator.

The rotating shaft 1 is magnetized in its axial direction, and a yoke of an electromagnet surrounds a portion forming one magnetic pole (in the embodiment shown in the figure, the N pole) at one end in the axial direction. 2 is placed. When the rotating shaft rotates, magnetic pole 2 of the electromagnet
The magnets a to 2h are excited by electromagnetic coils 3a to 3h, respectively, so that the side facing the rotating shaft 1 becomes the north pole.

Therefore, the rotating shaft 1 is rotatably supported in the air without contacting each magnetic pole due to the repulsion from each magnetic pole.

The other magnetic pole portion (S pole) at the other end of the rotating shaft 1 in the axial direction
The same is true for the part, and by exciting each magnetic pole of the electromagnet that surrounds it in a dissipation-isomorphic manner so that it becomes the S pole, the part is rotatably supported in the air without contact with each magnetic pole. A bearing with low friction torque, smooth rotation, usable at high and low temperatures, no oil contamination, and no problem of lubricating oil deterioration is achieved.

The distance between the rotating shaft 1 and each magnetic pole is adjusted by controlling the electric power supplied to the electromagnetic coils 3a to 3h to change the repulsive force. Therefore,
If the position of the rotating shaft 1 shifts due to changes in the load on the rotating shaft 1 or the influence of gravity, the electromagnetic coil 3a
It is possible to correct the above-mentioned deviation by adjusting the power supplied to each of the periods 3h to 3h. An example of this correction means will be explained below.

The rotation shaft displacement detectors 4a to 4h provided between each of the magnetic poles 2a to 2h and the rotation shaft 1 include, for example, a magnetic resistance element, and have a property that the resistance value thereof changes when the magnetic flux passing through it changes. are doing. Therefore, when the position of the rotating shaft 1 shifts and approaches or moves away from any of the rotating shaft displacement detectors 4a to 4h, the magnetic flux density distributed between each magnetic pole of the electromagnet and the rotating shaft changes, and as a result, the rotating shaft The resistance values of the displacement detectors 4a to 4h change. Therefore, if a constant current is always passed through the rotating shaft displacement detectors 4a to 54h, the change in the resistance value will be detected as a change in the voltage across the magnetoresistive element.

FIG. 2 shows an example of a circuit configuration in which the power supplied to the electromagnetic coils 3a to 3h is changed based on fluctuations in the outputs of the rotating shaft displacement detectors 4a to 4h to correct the deviation of the rotating shaft. It shows.

In Fig. 2, in order to avoid complication of the drawing, the outputs of the four electromagnetic coils 3a to 3d corresponding to the four rotary shaft displacement detectors 4a to 4d are shown based on the outputs of the four rotating shaft displacement detectors 4a to 4d. Although the configuration for controlling power is shown, the same applies to the remaining four electromagnetic coils 3e to 3h.

Changes in the terminal voltages of the rotating shaft displacement detectors 4a to 4d as described above are amplified by amplifiers 7a to 7d, respectively, and input to comparators 9a to 9d.

At the same time, the reference voltage from the reference voltage generator 8 is input to the comparators 9a to 9d, and compared with the input voltages of the amplifiers 7a to 7, respectively. For example, if the voltage of the rotating shaft displacement detector 4a amplified by the Feng amplifier 7a and input to the comparator 9a exceeds the reference voltage above a predetermined value, or is less than the reference voltage, the comparison is performed. A signal is sent from S9a to the pulse oscillator 10a to change the state of the pulse oscillated by the pulse oscillator 10a.

That is, for example, if it is assumed that the position of the rotating shaft 1 is displaced from its normal position and the distance from the magnetic pole 2a of the electromagnet increases, for example, the voltage from the rotating shaft displacement detector 4a increases from the reference value. A signal is sent from the comparator 9a to the pulse oscillator 10a, and the pulses generated by the pulse oscillator 10a are changed from, for example, those shown in FIG. 3 to those shown in B. This change is achieved by reducing or stepping down the oscillation frequency of the pulse oscillator 10a.

The switching element 6a is opened and closed by the output pulse from the pulse oscillator 10a, and is made conductive when the pulse is rising, for example, to supply current from the DC power source 5 to the electromagnetic coil 3a.

Therefore, the output pulse from the pulse oscillator 10a is
When the switch is switched from the middle of the figure to B-, the average current supplied to the electromagnetic coil 3a decreases, and as a result, the inverse 1 component force of the magnetic pole 2a also decreases, and the rotating shaft 1 moves closer to the magnetic pole 2a. The above deviation is corrected and the position is returned to the normal position.

In the opposite case, if the position of the beating rotation shaft 1 is displaced from its normal position and approaches the magnetic pole 2a of the electromagnet, increasing the frequency of the pulses emitted from the pulse oscillator 10a will cause the switching element to The number of conduction times per unit time of 6a increases, and therefore the average current supplied to coil 3a increases,
As a result, the repulsive force of the magnetic pole 2a increases, and the rotating shaft 1 is corrected to its normal position.

In the above embodiment, the current supplied to the electromagnetic coil is controlled by changing the frequency of the pulses oscillated by the pulse oscillator 10a. For example, as shown in FIG. The frequency of the oscillated pulse may be kept constant while the pulse width τon may be increased or decreased. That is, when increasing the repulsive force of the magnetic pole, the pulse width is widened as shown in Figure 4 to lengthen the conduction time of the switching element, and when the repulsive force of the magnetic pole is decreased, the pulse width is increased as shown in Figure B. The conduction time of the switching element is shortened by narrowing the conduction time of the switching element.

In the above description, the case where the repulsive force of the electromagnetic coil 3a is controlled to increase or decrease based on the output of the rotating shaft displacement detector 4a has been described, but the same applies to the other electromagnetic coils 3b to 3h.

FIG. 5 is a cross-sectional view along the axial direction showing another embodiment of the apparatus for implementing the rotating shaft support method according to the present invention, in which 11 is the rotating shaft, 12 is the rotating shaft 11. fixed,
The disk bodies 13 and 14 magnetized in the axial direction have a plurality of magnetic pole parts 13a, 13a and 14a, respectively.

Electromagnets 14a, 16a, 17a, and 1.7a are fixed to a suitable casing 15 in such a manner as to sandwich the disc body 12 with a small gap therebetween; This is a rotational shaft displacement detector that detects displacement, that is, displacement of the rotational shaft 11 in the axial direction.

The disk body 12 fixed to the rotating shaft 11 is magnetized in the axial direction, for example, the left side in the figure is the north pole and the right side is the south pole.
It is magnetized so that it becomes a pole.

When rotating the rotating shaft 11, the sides of the magnetic pole parts 13a, 13a of the electromagnet 13 that face the disc become the north pole, and the sides of the magnetic pole parts 14a, 14a of the electromagnet 14, facing the disc become the south pole. energize each electromagnetic coil.

In such a case, the disk body 12 receives the repulsive force of each of the magnetic poles and is rotatably supported in a non-contact state with a slight gap between the two types of magnets 13 and 14, thereby forming a thrust bearing. .

When an axial shift or inclination of the rotating shaft 11 occurs, the rotating shaft displacement detector 16a is activated as in the previous embodiment.

A change occurs in the magnetic flux passing through 16a, 1.7a, and 17a, and this is detected by each detector. Based on these output signals, each magnetic pole part 13a of electromagnets 13 and 14 changes.
.

The disk body 12 is held at a constant position by controlling the power applied to each of the electromagnetic coils 13a, 14a, and 14a as described above.

Note that the support device shown in FIG. 1 and the support device shown in FIG. 5 are used together for one rotating shaft, and the support device shown in FIG. When the support device shown in Fig. 5 is used only to prevent displacement of the rotating shaft in the axial direction, the electromagnetic coils of the electromagnets 13 and 14 are removed only when displacement of the rotating shaft in the axial direction is detected. It is also possible to energize.

Next, with reference to FIGS. 6 to 8, different embodiments regarding the magnetization direction of the disc body in the surface mounting according to the present invention and the arrangement of the electromagnets with respect to the magnetization direction will be described.

The disk body 12 in the support device shown in FIG.
and is magnetized in its axial direction.

The electromagnets 18 are disposed along the outer periphery of the disc body in a radially uniform manner around the rotating shaft 11, and both magnetic poles thereof exert a repulsive force on the disc body 12 along its radial direction, as shown in the figure. This forms a radial bearing.

Alternatively, like the electromagnet 19, both magnetic poles are connected to the disc body 1.
It is also possible to arrange the electromagnet in such a way as to sandwich the peripheral edges of the electromagnets 2 and 2 so that the repulsive force of the electromagnet acts in the axial direction, thereby functioning as a thrust bearing.

The disk body 12 in the support device shown in FIG.
and is magnetized along its radial direction. The electromagnets 20 are disposed along the outer periphery of the disc body in a radially uniform manner around the rotating shaft 11, and their magnetic poles are aligned with the disc body 12 as shown in the figure.
A repulsive force is exerted along the radial direction of the bearing, thereby forming a radial bearing.

Alternatively, it is also possible to use an electromagnet 21 whose repulsive force acts in the axial direction so that it functions as a thrust bearing.

The disk body 12 in the support device shown in FIG.
and is magnetized along its radial direction. The electromagnet 22 has one magnetic pole placed near the center of the disk 12 to exert a repulsive force along the axial direction on the disk, and the other magnetic pole facing the outer periphery of the disk. It is configured to apply a repulsive force along the radial direction to the body, thereby achieving the function of both a thrust bearing and a radial bearing.

〔Effect of the invention〕

Since the present invention is constructed like ironwork, the present invention has low friction torque, smooth rotation, can be used at high and low temperatures, is completely free from oil contamination, has no problem with deterioration of lubricating oil, and can rotate smoothly. A method and apparatus for supporting a rotating shaft are provided which have many advantages such as being able to control the position of the shaft accurately and quickly and having a very compact structure.

Note that the configuration of the present invention is not limited to the embodiment of ironwork. That is, for example, the number of magnetic poles of the electromagnet can be increased or decreased as necessary, and the arrangement of the electromagnet can also be changed as appropriate.In addition to the above-mentioned magnetic resistance element, a Hall element or a differential transformer type electromagnetic coil can also be used as a rotating shaft displacement detector. In addition, the means for controlling the power to the electromagnet may be controlled by voltage other than the pulse current, and the control circuit may employ various known circuit configurations. are possible, and therefore the present invention encompasses all modifications and variations that can be readily conceivable by those skilled in the art from the above description within the scope of its purpose.

[Brief explanation of the drawing]

FIG. 1 is an axis-perpendicular sectional view showing an embodiment of a device for implementing the rotating shaft support method according to the present invention, and FIG. 2 is an embodiment of a circuit for operating the device shown in FIG. FIGS. 3 and 4 are block diagrams showing different examples of pulsed currents for controlling the above device, and FIGS.
The figure is a sectional view along the axial direction showing another embodiment of the apparatus for carrying out the rotating shaft supporting method according to the present invention, and FIGS. 6 to 8 show the carrying out the rotating shaft supporting method according to the present invention. FIG. 4 is an explanatory diagram showing the magnetization direction of a disc body and the different arrangement of electromagnets therewith in a device for doing so.

Claims (1)

[Claims] 1) A part of a shaft that is rotatably supported and rotates at high speed, or a disc attached to the shaft, is magnetized in the axial direction or radial direction, and a repulsive force is applied to the magnetized part in opposition to it. A method for supporting a rotating shaft, comprising: providing an electromagnet to act on the rotating shaft, thereby holding the rotating shaft or disk body at a desired position. 2) The rotating shaft supporting method according to claim 1, wherein the current supplied to the electromagnet is a pulsed current. 3) The rotating shaft support method according to claim 1 or 2, wherein the electromagnet is energized only when abnormal displacement of the shaft or the disc body is detected. 4) A rotating shaft consisting of a rotating shaft to be supported that is magnetized in the axial or radial direction, or a disk attached to the rotating shaft, and a plurality of electromagnets disposed in a radiating shape around the rotating shaft to fit the rotating shaft. Support device. 5) Claim 4, wherein the shaft or disc body is magnetized in the axial direction, and the repulsive force of the electromagnet acts in the axial direction.
Rotating shaft support device as described in section. 6) The rotating shaft support device according to claim 4, wherein the shaft or disk body is magnetized in the axial direction, and the repulsive force of the electromagnet acts in the radial direction. 7) The rotating shaft support device according to claim 4, wherein the shaft or disk body is magnetized in the radial direction, and the repulsive force of the electromagnet acts in the axial direction. 8) The rotating shaft support device according to claim 4, wherein the shaft or disc body is magnetized in the radial direction, and the repulsive force of the electromagnet acts in the radial direction.