# US 5,348,313 A · Radial shaft sealing ring

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- Number: US 5,348,313 A
- Document ID: US5348313A
- Status: Granted
- Kind: A
- Application number: 08/020,851
- Filed: 1993-02-19
- Granted: 1994-09-20
- Earliest claimed: 1991-08-01
- Assignees: Leybold Aktiengesellschaft
- Inventors: Anton Pawlakowitsch
- Web page: https://patentgrep.com/patent/US5348313A

## CPC

- F16J 15/324: Arrangements for lubrication or cooling of the sealing itself
- F16J 15/40: by means of fluid
- Y10S 277/904: Viscous seal
- Y10S 277/913: Seal for fluid pressure below atmospheric, e.g. vacuum
- F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

The invention relates to a shaft seal for sealing a shaft pass-through (3) of vacuum apparatus, which accommodates a shaft (2), having at least one annular seal (4) which is disposed in a housing part and with which a barrier liquid (5) is associated, while the sealing part (6) of the annular seal facing the shaft (2) forms with the shaft an annular chamber (8) in which the barrier liquid (5) is provided, in order in this manner to bind particles formed by attrition.

## Claims

### Claim 1

A shaft seal for sealing a passage accommodating a rotary shaft in vacuum apparatus having a housing part, comprising:
at least one annular sealing member having a lower high pressure side and an upper low pressure side and disposed in a housing part, the sealing member forming with the rotary shaft an upper annular chamber for accommodating a blocking liquid as a pool;
the sealing member having between the low pressure side and the high pressure side a single sealing lip adjoining the annular chamber which is upwardly open to a vacuum chamber while the shaft is rotating normally;
the sealing member and the rotary shaft having a central axis which runs in a vertical direction; and
a blocking liquid of high molecular weight disposed in the annular chamber as a pool and having a total upper pool surface upwardly open to the vacuum chamber while the shaft is rotating normally, the blocking liquid of the annular chamber being pooled against the sealing member in contact with the vacuum chamber in such manner that the total upper surface of the pool of the blocking liquid has a direct contact with the vacuum chamber and is fully exposed thereto while the shaft is rotating normally.

### Claim 2 (depends on 1)

Shaft seal according to claim 1, in which the annular chamber for the accommodation of the barrier liquid flares funnel-wise from the sealing lip to the low pressure side.

### Claim 3 (depends on 1)

Shaft seal according to claim 1, in which the sealing member has a radially reaching inner edge and in which the distance between the radially reaching inner edge, the sealing lip and the shaft is selected according to the viscosity of the barrier liquid.

### Claim 4 (depends on 1)

Shaft seal according to claim 1, in which the barrier liquid consists of a high-molecular weight liquid.

### Claim 5 (depends on 1)

Shaft seal according to claim 1, in which the barrier liquid consists of a high-molecular weight oil.

### Claim 6 (depends on 1)

Shaft seal according to claim 1, in which the annular sealing member has an end face and in which the barrier liquid extends beyond the annular chamber and also covers the end face of the annular seal.