JP2553059Y2 - Superconducting bearing device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The superconducting bearing device according to the present invention is used for supporting a rotating shaft which rotates at a very high speed, such as a centrifuge.

[0002]

2. Description of the Related Art It is difficult to support a rotating shaft, which is installed in a centrifuge and the like at an ultra-high speed, with a normal rolling bearing. Bearing devices are used.

In order to hold the rotating shaft in a floating state by the magnetic bearing device, a plurality of electromagnets are provided in each of the radial direction and the thrust direction, and based on a signal from a sensor for detecting the position of the rotating shaft. The amount of electricity to each electromagnet is adjusted to adjust the position of the rotating shaft in the radial and thrust directions.

[0004] Such a magnetic bearing device is not only increased in size by providing a plurality of electromagnets, but also needs to immediately cancel the displacement of the rotating shaft and requires a control circuit that responds quickly, thus increasing the cost. Things are inevitable.

For this reason, as described in the magazine "Nikkei Mechanical" No. 331 (published on September 3, 1990) published by Nikkei BP, a superconducting bearing device utilizing the Meissner effect of a superconductor has been studied. Have been.

[0006] The Meissner effect of a superconductor means that when a superconductor and a permanent magnet are opposed to each other, they repel each other when they come closer than a certain distance, and conversely, when they both separate more than a certain distance. Refers to the phenomenon of pulling. By such a Meissner effect, the superconductor and the permanent magnet are
It is considered that a superconducting bearing device which does not require a position sensor or a control circuit at all can be maintained because it can be maintained at a fixed distance.

As a structure for forming a superconducting bearing device for supporting a rotating body in a radial direction and a thrust direction by utilizing the Meissner effect as described above, for example, the structure shown in FIG. Conceivable.

A short columnar permanent magnet 2 is fixed to the lower end surface of the rotating shaft 1 concentrically with the rotating shaft 1. Permanent magnet 2
Is provided with a cylindrical superconductor 5 having a bottom so that the permanent magnet 2 and the rotating shaft 1 are rotatably supported in a floating state. That is, the disk 6 and the permanent magnet 2
The permanent magnet 2 is inserted from above into a superconductor 5 formed by combining a cylinder 7 having an inner diameter r slightly larger than the outer diameter d.

With the permanent magnet 2 inserted into the superconductor 5 in this manner, the lower end surface 3 of the permanent magnet 2 is placed on the upper surface 6a of the disk 6, and the outer peripheral surface 4 of the permanent magnet 2 is placed on the inner periphery of the cylinder 7. Surface 7a
, Respectively, with bearing gaps 8a and 8b interposed therebetween. That is, the lower end surface 3 is a thrust-side supported surface, the outer peripheral surface 4 is a radial-side supported surface, the upper surface 6a is a thrust-side supported surface, and the inner peripheral surface 7a is a radial-side supported surface.

Further, a cooler 9 is provided around the superconductor 5.
Is provided so that the superconductor 5 is cooled from the outside and kept in a superconducting state. That is, the inside of the cooler 9 is filled with a low-temperature coolant such as liquid helium, liquid nitrogen, or the like, and the coolant allows the superconductor 5 to be cooled.

While the superconductor 5 is cooled and maintains the superconducting state, the dimensions h ₁ and h ₂ of the bearing gaps 8a and 8b are kept constant by the Meissner effect. 2 and the rotating shaft 1 are held in bearings in a floating state.

[0012]

SUMMARY OF THE INVENTION The superconducting bearing device constructed and operated as described above has an effect of being able to support a rotating body rotating at an extremely high speed despite the fact that complicated components such as a control circuit are unnecessary. On the other hand, as a force to support the rotating body,
Since only the levitation force due to the Meissner effect is used, the load capacity of the bearing device is limited, and the application is limited.

The purpose of the superconducting bearing device of the present invention is to widen its use by increasing the load capacity.

[0014]

A superconducting bearing device according to the present invention has a magnet having a supported surface and a superconducting surface provided below the magnet and opposed to the supported surface via a bearing gap. A body, a cooler for cooling the superconductor,
One end is opened on the bearing surface of the superconductor, and a discharge passage for discharging a coolant for cooling the cooler into the bearing gap.

[0015]

In the case of the superconducting bearing device of the present invention configured as described above, the superconducting member is cooled by a coolant, and the superconducting member is lifted by the Meissner effect acting between the magnet and the superconducting member which maintains the superconducting state. The dimension of the bearing gap existing between the bearing surface of the magnet and the supported surface formed on the magnet is kept constant, and the magnet is held in a floating state.

On the other hand, the coolant present in the cooler is discharged into the bearing gap through the discharge passage, and increases the pressure in the bearing gap. As a result, the load applied to the magnet is supported not only by the Meissner effect but also by the pressure fluid existing in the bearing gap.

As a result, the load capacity of the superconducting bearing device increases, and the use of the superconducting bearing device can be expanded.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the illustrated embodiment.

FIG. 1 shows a first embodiment of the present invention.
A short columnar permanent magnet 2 is fixed to the lower end face of the rotating shaft 1, and a cylindrical superconductor 5 having a bottom is provided around the permanent magnet 2.
To allow the permanent magnet 2 and the rotating shaft 1 to be rotatably supported in a floating state. That is, the disk 6 and
The permanent magnet 2 is inserted from above into a superconductor 5 formed by combining a cylinder 7 having an inner diameter r slightly larger than the outer diameter d of the permanent magnet 2.

With the permanent magnet 2 inserted in the superconductor 5 in this manner, the lower end surface 3 of the permanent magnet 2 is placed on the upper surface 6a of the disk 6, and the outer peripheral surface 4 of the permanent magnet 2 is placed on the inner periphery of the cylinder 7. Surface 7a
, Respectively, with bearing gaps 8a and 8b interposed therebetween. That is, the lower end surface 3 is a thrust-side supported surface, the outer peripheral surface 4 is a radial-side supported surface, the upper surface 6a is a thrust-side supported surface, and the inner peripheral surface 7a is a radial-side supported surface.

Further, a cooler 9 is provided around the superconductor 5.
Is provided so that the superconductor 5 is cooled from the outside and is maintained in a superconducting state. That is, the inside of the cooler 9 is filled with a low-temperature coolant such as liquid helium, liquid nitrogen, or the like, and the coolant allows the superconductor 5 to be cooled.

The above configuration is the same as the above-described conventional superconducting bearing device, but in the superconducting bearing device of the present invention, the upper surface which is the bearing surface of the superconductor 5 is also provided. One ends of the discharge passages 10a and 10b are opened in the inner peripheral surface 7a and the inner peripheral surface 7a, respectively.

More specifically, a pocket 11a is provided on the upper surface 6a and a pocket 11b is provided on the inner peripheral surface 7a.
A pocket 13 is provided on an inner peripheral surface portion of the cooler 9, and a pocket 14 is provided on a bottom portion of the cooler 9, and the pocket 11 a and the pocket 14 are connected to the discharge passage 1.
Oa makes the pocket 11b and the pocket 13 communicate with each other through the discharge passages 10b and 10b.

As the superconducting material constituting the superconductor 5, various superconducting materials that have been conventionally proposed can be used, but a so-called high-temperature superconducting material which is brought into a superconducting state by liquid nitrogen can be preferably used. In particular, as it is described in the magazine "Nikkei Mechanical" mentioned above, yttrium-based, commonly referred to as "123" phase, the superconducting phase having a composition represented by YBa ₂ Cu ₃ O _n, "211" called phase, Y superconducting materials were uniformly mixed fine powder of the normal conductive phase represented by ₂ BaCuO _n, obtained a greater lifting force by the Meissner effect, since it can increase the load capacity of the superconducting bearing device, It can be used preferably.

In the case of the superconducting bearing device of the present invention configured as described above, the superconductor 5 and the permanent magnet 2 which are cooled by the coolant filled in the cooler 9 and are kept in a superconducting state.
The permanent magnet 2 and the rotating shaft 1 are held in a floating state by a floating force due to the Meissner effect that acts between them.

That is, the size of the bearing gap 8a extending between the upper surface 6a of the disk 6 of the superconductor 5 and the lower end surface 3 of the permanent magnet 2 in the thrust direction, the inner peripheral surface 7a of the cylinder 7, and The dimension of the bearing gap 8b in the radial direction existing between the outer peripheral surface 4 of the permanent magnet 2 and the outer peripheral surface 4 is kept constant by the Meissner effect. As a result, the positioning of the permanent magnet 2 is achieved in both the thrust direction and the radial direction, and the permanent magnet 2 and the rotating shaft 1 are held in a floating state. It becomes rotatable.

On the other hand, the pressure gas generated by the evaporation of the coolant in the cooler 9 is discharged to the bearing gaps 8a and 8b through the discharge passages 10a and 10b. That is, the pressure gas (helium gas or nitrogen gas) generated by evaporating the coolant (liquid helium or liquid nitrogen) filled in the cooler 9 is supplied to the pocket provided on the cooler 9 side. 13,1
After being collected by the cartridge 4, it is fed into the pockets 11 a, 11 b provided on the superconductor 5 side through the respective discharge passages 10 a, 10 b, and discharged from the pockets 11 a, 11 b into the bearing gaps 8 a, 8 b. Increase the pressure in 8a, 8b.

As a result, the thrust and radial loads applied to the permanent magnet 2 are supported not only by the Meissner effect but also by the pressurized gas present in the bearing gaps 8a and 8b.

As a result, the load capacity of the superconducting bearing device increases, and the use of the superconducting bearing device can be expanded. Further, in the case of the conventional superconducting bearing device, when the superconducting state of the superconductor 5 collapses due to a rise in temperature or the like, the Meissner effect between the superconductor 5 and the permanent magnet 2 instantaneously increases. If the permanent magnet 2 rotates at high speed, the permanent magnet 2 and the superconductor 5 may be strongly rubbed against each other, damaging both members 2 and 5. In the case of a superconducting bearing device, since the permanent magnet 2 is supported not only by the levitation force due to the Meissner effect but also by the pressurized gas, the permanent magnet 2 and the superconductor 5 are not strongly rubbed in such a case, The two members 2 and 5 are not damaged.

The pressure fluid discharged into each of the bearing gaps 8a and 8b may be a pressure gas generated by evaporating the coolant in the cooler 9 or an unevaporated liquid coolant. good. The bearing formed in the bearing gaps 8a and 8b by the pressure fluid may be a hydrostatic bearing, a hydrodynamic bearing, or a combination of both. In forming the hydrostatic bearing, all or a part of the upper surface 6a of the disk 6 of the superconductor 5 and the inner peripheral surface 7a of the cylinder 7 are formed of a porous material, and the pressure is reduced from the porous material. Fluid can also be ejected. When a hydrodynamic bearing is formed, a hydrodynamic groove is formed on at least one of the opposing surfaces of the permanent magnet 2 and the superconductor 5.

FIG. 2 shows a second embodiment of the present invention. In the case of this embodiment, the supply port 15 provided in the cooler 9,
The coolant can be sent through pockets 16 into pockets 13 and 14 provided on the inner peripheral surface and the bottom surface of the cooler 9. The cooler 9 is also provided with a supply port 17 for sending the coolant to portions other than the two pockets 13 and 14.

In the case of the present embodiment, the coolant sent from the supply ports 15 and 16 cools the cooler 9 and then is sent to the pockets 13 and 14 and further the discharge passages 10a and 10a.
b, each bearing gap 8a, 8b from the pocket 11a, 11b
Blow out. As a result, the amount of the pressurized fluid fed into each of the bearing gaps 8a and 8b becomes sufficient and stable.

If the coolant sent from the supply ports 15 and 16 into the cooler 9 and the coolant sent from the supply port 17 into the cooler 9 are made to be the same or free to mix, the respective supply ports 15 , 16, and 17, a common supply means for sending the coolant, and the pressure gas generated by the evaporation of the coolant in the cooler 9, together with the coolant sent from the supply ports 15 and 16, It can be fed into the bearing gaps 8a and 8b.

The other constructions and operations are the same as those of the first embodiment.

In each of the embodiments, the pockets 13 and 14 for storing the coolant are replaced with the inner peripheral surface and the bottom surface of the cooler 9 or together with the inner peripheral surface and the bottom surface of the cooler 9. It can be provided on the outer peripheral surface and the lower surface of the body 5.

The superconducting bearing device of the present invention can be used not only as a bearing for rotational movement as shown in the figure, but also as a bearing for linear movement.

[0037]

The superconducting bearing device of the present invention is constructed and operates as described above, so that a large load capacity can be obtained and the use of the superconducting bearing device can be expanded.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing a second embodiment.

FIG. 3 is a sectional view showing a conventional example.

[Explanation of symbols]

 Reference Signs List 1 rotating shaft 2 permanent magnet 3 lower end surface 4 outer peripheral surface 5 superconductor 6 disk 6a upper surface 7 cylinder 7a inner peripheral surface 8a bearing gap 8b bearing gap 9 cooler 10a discharge passage 10b discharge passage 11a pocket 11b pocket 13 pocket 14 pocket 15 Supply port 16 Supply port 17 Supply port

Claims (1)

(57) [Scope of request for utility model registration] 1. A magnet having a supported surface, a superconductor provided below the magnet and having a bearing surface facing the supported surface via a bearing gap, and a cooler for cooling the superconductor. A discharge passage that opens one end to the bearing surface of the superconductor and discharges the coolant present in the cooler into the bearing gap.