JPS61270519A - Protective device of gas bearing - Google Patents

Abstract

PURPOSE:To prevent seizure phenomenon due to the shortage of gas in the captioned gas bearing by supplying lubricating oil, in case of shortage of gas in the gas bearing, into the gas bearing for operating said gas bearing as a lubricating oil bearing. CONSTITUTION:Gas is supplied into a gas bearing 1 through duct lines B, B-2, B-3. A duct line B-1, at one end thereof, is intercommunicated with a duct line B-3 while at the other end thereof with the upper end part of a pot 2 through a check valve C-2 and a duct line B-4, at one end thereof, is intercommunicated with the lower end part of the pot 2 while at the other end thereof with a duct line B through a check valve C-1. The upper part of the pot 2 serves as an air chamber 2a while the lower part thereof, as a receiver of lubricating oil 3. In this case, liquid surface of lubricating oil 4 is set at a lower position, to a predetermined distance l, than that of a junction P between the gas bearing 1 and the conduct line B.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gas bearing protection device for preventing seizure of a gas bearing.

``Prior Art'' In gas bearings, when the gas flow rate or the gas pressure decreases while the shaft is rotating, seizure occurs in the gap between the bearing and the shaft. Therefore, in the conventional protection device, in such a case, gas is replenished from a spare gas holder to avoid the seizure phenomenon.

``Problems to be Solved by the Invention'' However, gas replenishment from the gas holder is often not performed sufficiently while the shaft is rotating, and this phenomenon becomes even more pronounced when the shaft accuracy is high. Met.

Therefore, the conventional protection device has the disadvantage that the phenomenon of burn-in cannot be sufficiently avoided.

This invention was made in view of two consecutive circumstances.
It is an object of the present invention to provide a gas bearing protection device that can sufficiently avoid the phenomenon of seizure.

"Means for Solving the Problems-1" In order to solve the above-mentioned problems, the present invention provides a protection device for a gas bearing, in which when the gas in the gas bearing is insufficient, the gas bearing is lubricated. A lubrication 413 supply unit is provided that supplies M1 and causes the gas bearing to operate as a lubrication 4[j bearing.

"Operation" When the gas in the gas bearing becomes insufficient, the gas bearing immediately operates as a lubricating oil bearing.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing the configuration of an embodiment of the present invention.

In the figure, 1 is a gas bearing, and pipes B, B-2,
13-3 so that the gas is supplied. Next, B-1 has one end connected to conduit B-3, and the other DM:
is the upper end of the bot 2 through the check valve C-, 2? 13-4 is a pipe whose end communicates with the lower end of the bot 2 and whose other end communicates with the pipe B via the check valve C-1. It is a road.

A part of the bot 2 serves as an air chamber 2a, and a lubricating oil 3 is placed in the bot 2.

In this case, the liquid level of the lubrication AI+3 is set at a position P lower by a predetermined distance θ than the junction point between the gas bearing I and the conduit B.

In the two-legged configuration, when gas is fed into the pipe B-3, this gas is fed into the gas bearing 1 through the route B-2-C-3-Pipe B, and also into the gas bearing 1 through the pipe B-3. 1
- Sent into the air chamber 2a via the check valve C-2. In this case, the pressure in each pipe B, B-1 to B-4 and the air chamber 2
The pressure in a is approximately the same as that in a, and the lubrication r41] 3
Since the liquid level is set lower than the junction point P,
This lubricating oil 3 will not flow out via the check valve C-1. -3 = Even if there is some pressure fluctuation, the liquid level of the lubricating oil 3 is set low, so unnecessary lubricating oil will not flow out.

That is, in this state, only gas is supplied into the gas bearing 1.

On the other hand, during the rotation of the gas bearing I, for some reason the pipe B-
3, the gas supply to pipes B, B~1~B-3 is cut off.
The pressure inside becomes lower than the pressure inside the air chamber 2a, and as a result, the lubricating oil 3 inside the bot 2 is pushed out by the pressure of the air chamber 2a, and the lubricating oil 3 inside the bot 2 is pushed out through the check valve (, -1, pipe B). In other words, in this embodiment, when the pressure inside the gas bearing 1 decreases, the lubricating oil 3 immediately flows into the gas bearing 1.
flows in, thereby causing the gas bearing 1 to operate as a lubricating oil bearing.

FIG. 2 is a schematic configuration diagram showing the configuration of a modified example of this embodiment, and parts corresponding to those in FIG.

This modification differs from the above embodiment in that a solenoid valve 5 is provided in place of the check valve C-1, and the opening and closing of this solenoid valve 5 is controlled by the pipe B-1.
2 or a power outage detector (not shown). In this case, the pressure detector 6 has a switch that is switched when the pressure in the J pipe B-2 (that is, the pressure in the gas bearing I) falls below the set pressure. When a power failure occurs, the solenoid valve 5 is opened.Also, when a power failure is detected by the power failure detection circuit, the solenoid valve 5 is opened. When the switch is turned off, the battery or the like 1 backs up the driving of the solenoid valve 5, thereby preventing the solenoid valve 5 from opening.

In this modification, since the opening/closing control is electrical using the solenoid valve 5, there is an advantage that the control is highly reliable.

In each of the above embodiments, the outlet side of the check valve C-1 or the outlet side of the solenoid valve 5? A spray nozzle or the like may be provided to supply the lubricating oil 3 in the form of oil mist into the gas bearing 1.

Furthermore, instead of the lubricating oil supplying means such as the bot 2 described above, a liquid supplying device that electrically supplies lubricating oil using a pump, an electric piston, etc. may be provided.

As explained in "Effects of the Invention, 1 and 2", according to the present invention, in the gas bearing protection device, when the gas in the gas bearing is insufficient, the lubricant 7111 is automatically inserted into the gas bearing. supply, 1
1st Edition Make the gas bearing operate as a lubricant bearing.Since it is equipped with a lubricant supply section, in an emergency, the gas bearing can instantly be used as a lubricant bearing, making the protective operation of the gas bearing extremely reliable. In addition to the advantages, it also has various effects as described below.

■It can be configured by combining simple parts, and can be easily adapted to existing products.

■Even after operating as a lubricant bearing, its operation is stable and highly reliable even after a long period of time.

■Easy to maintain and manage.

■If you use clean lubricating oil, it will not take much effort even when you use it as a gas bearing again.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing the configuration of an embodiment of the present invention;
FIG. 2 (J is a schematic configuration diagram showing a modified example of the same embodiment. 2... Pot (lubricating oil supply section), 3... Lubricating oil, 5
・Solenoid valve (lubricating oil supply part), 6...pressure detector (
Lubricating oil supply section), C-1, (, -2, C-3-... Check valve (lubricating oil supply section).

Claims (3)

[Claims] (1) The gas bearing protection device includes a lubricating oil supply unit that supplies lubricating oil into the gas bearing and causes the gas bearing to operate as a lubricant bearing when the gas in the gas bearing is insufficient. A gas bearing protection device characterized by: (2) The lubricating oil supply section includes a pot containing lubricating oil with a space left in the upper part, and a first pipe line communicating between the upper end of the pot and the gas supply pipe line. , a second conduit communicating between the lower end of the pot and the gas inlet of the gas bearing; and a second conduit provided in the first conduit so that the gas in the space does not flow into the gas supply conduit. Claim 1 characterized in that it comprises a check valve that makes the
Protective device for gas bearings as described in section. (3) The gas bearing protection device according to claim 1, wherein the lubricating oil supply section includes a spraying device that turns the lubricating oil supplied to the gas bearing into an oil mist.