JPS5821984Y2 - Shinkushitsuno Exhaust High Shutsouchi - Google Patents

Description

[Detailed description of the invention] In a rotating anode cathode X-ray generator, it is necessary to prevent lubricating oil from leaking into the vacuum chamber from the shaft seal for introducing the rotating shaft of the anode cathode into the vacuum chamber. do not have.

Therefore, the oil accumulated in the vacuum chamber must be discharged from time to time, but the present invention provides a device with a simple structure that can discharge the liquid in the vacuum chamber to the atmosphere while maintaining the vacuum. It is.

FIG. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, and FIG. 2 is a side view of the apparatus shown in FIG. It is introduced into the vacuum chamber 3 through the vacuum chamber 3.

The shaft seal 2 maintains a vacuum by supplying a large amount of lubricating oil, such as oil for a diffusion pump, which has an extremely low vapor pressure, and the oil enters the vacuum chamber 3 along the surface of the shaft 1.

Therefore, a collar 4 is provided on the shaft 1 to scatter the oil using centrifugal force and collect it in a liquid reservoir 5.As shown in the figure, this liquid reservoir 5 is formed at a position lower than the above liquid reservoir in the vacuum wall of the cylinder. The cylinder is connected to the side surface of the cylinder by a liquid passage 7, and the proximal end of the cylinder is connected to the liquid reservoir by a passage 8.

A piston 10 having an O-ring 9 is slidably fitted into the cylinder 6, and its drive rod 11 is drawn out into the atmosphere from the base end of the cylinder via an 0'J tongue 2.

A hole 13 is provided at the tip of the cylinder 6, and an O-ring 14 is fitted into the stepped portion of the hole, and a screw 16 that slides into the O-ring 15 is screwed into the hole.

The head of this screw 16 protrudes into the atmosphere, and its tip faces the O-ring 14.

Therefore, when the screw 16 is tightened, the tip comes into pressure contact with the O-ring 14 and the hole 13 is closed.
7 is formed.

The proximal end of a thin tube 18 having an inner diameter of 1 mm or less and a length of about 1 m, for example, is connected to such a hole 13, and the tip 19 of the thin tube is opened to the atmosphere.

In the device described above, the spring screw 16 is always tightened to close the valve 17.
Close hole 13 with.

Therefore, the vacuum chamber 3 and cylinder 6 are completely sealed,
It is evacuated to a high vacuum using an exhaust pump (not shown).

When the shaft 1 is rotated in this state, oil 20 is gradually accumulated in the liquid reservoir 5, and a portion of the oil 20 flows into the cylinder 6 through the passage 7 as shown in the figure.

When the oil 20 is to be discharged, the valve 17 is opened as shown in the figure, and the rod 11 is driven back and forth as shown by arrow a.

That is, when the piston 10 moves upward in FIG. 1 due to this reciprocating drive, the oil in the cylinder 6 is discharged from the hole 13 through the thin tube 18 into the atmosphere.

And when the piston 10 moves downward in FIG.
The oil filling the thin tube 18 flows back into the cylinder 6 at a slow speed due to the flow resistance.

Therefore, by moving the piston 10 quickly and forming the passage 7 sufficiently large, the oil 20 in the liquid part 5 can be
fills the cylinder 6 again, and then the piston 10
During the upward movement in the figure, the oil passes through the thin tube 18 and is discharged from the tip 9 into the atmosphere.

That is, assuming that the specific gravity of the oil 20 is 1.07 and the kinematic viscosity is 40 centistokes, the flow rate of the oil flowing backward through the thin tube 18 having the above dimensions is only about 0.1 cc per second. The vacuum is maintained by oil in the thin tube 18.

As described above, the device of the present invention maintains a vacuum by the resistance of the liquid flowing through the thin tube, and does not require a check valve that requires complicated and precise machining, so the device can be manufactured easily.

Moreover, by bending the thin tube, it can be accommodated in an extremely small volume, so that the device can be made compact.

Although the above embodiment describes the case where the present invention is used in a rotating anticathode It can also be used when extracting distilled liquid from a distillation apparatus, extracting leaked lubricating oil from a centrifugal separation apparatus in vacuum, replacing lubricating oil from a turbo molecular pump, etc.

For example, in a turbo molecular pump, a rotating shaft with many blades rotates at a high speed of several hundred revolutions per minute, and the low vacuum side of the blades is maintained at about 10 hours using an oil rotary pump, etc., and the gas molecules on the high vacuum side are 1O-9 by hitting it with
A high vacuum of ~10 mmHfO is obtained, and the lubricating oil for the rotating shaft is forcibly circulated by a pump from an oil reservoir on the low vacuum side.

When a turbo molecular pump as mentioned above is operated continuously for a long period of time, the lubricating oil must be replaced without breaking the vacuum.In such cases, the present invention can also be used to replace the lubricating oil in the vacuum chamber. Can be discharged.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is a side view of the apparatus shown in FIG. 1. In the figure, 1 is the rotating shaft, 2 is the shaft seal, 3 is the vacuum chamber, 4 is the collar, 5 is the liquid part, 6 is the cylinder, T is the liquid passage, 8 is the liquid passage, 9HO! , pump, 10 is piston,
11 is a piston drive rod, 12 is an O-ring, 13 is a hole, 14 is an O-ring, 15 is an O-ring, 16 is a screw, 1
1 is an on-off valve, 18 is a thin tube, 19 is the tip of the thin tube, and 20 is oil.

Claims (1)

[Scope of utility model registration request] A passage connecting the liquid reservoir in the vacuum chamber to the side surface of a cylinder formed at a position lower than the liquid reservoir is provided, and the driving rod of the piston, which is slidably fitted in the cylinder, is introduced into the atmosphere from the base end of the cylinder. The drawer is connected to the tip of the cylinder with the proximal end of a thin tube through which the liquid in the liquid reservoir flows with high resistance, the tip of the thin tube is opened to the atmosphere, and an on-off valve is provided between the cylinder and the tip of the thin tube. A liquid evacuation device for the vacuum chamber provided.