# US 4,391,474 A · Thrust shaft seal with slidably mounted bearing sleeve

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- Number: US 4,391,474 A
- Document ID: US4391474A
- Status: Granted
- Kind: A
- Application number: 06/238,334
- Filed: 1981-02-26
- Granted: 1983-07-05
- Earliest claimed: 1981-02-26
- Inventors: Leonard J. Martini
- Web page: https://patentgrep.com/patent/US4391474A

## CPC

- F16J 15/3256: comprising two casing or support elements, one attached to each surface, e.g. cartridge or cassette seals
- B63H 23/321: {Bearings or seals specially adapted for propeller shafts}
- B63H 2023/327: {Sealings specially adapted for propeller shafts or stern tubes}
- Y10S 277/91: O-ring seal
- F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS
- B63H: MARINE PROPULSION OR STEERING (propulsion of air-cushion vehicles B60V1/14; specially adapted for submarines, other than nuclear propulsion, B63G; specially adapted for torpedoes F42B19/00)
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A seal for a thrust shaft in a body wherein the body has a bore and a counterbore, the bottom of the counterbore providing a shoulder for the thrust force of the shaft. The seal includes a bearing sleeve which is slidably mounted on the shaft, the bearing sleeve having a static O-ring which seals the interior of the sleeve to the shaft and a flange which extends into the counterbore. Provision is made for radially fixing the bearing sleeve to the shaft. A ring-shaped seal housing is mounted about the shaft below the bearing sleeve and extends into the counterbore, the seal housing having an interior dynamic O-ring sealing the housing to the shaft and an exterior static O-ring which seals the housing to the counterbore.

## Claims

### Claim 1

A seal for a thrust shaft in a body wherein the body has a bore and a counterbore, comprising:
a bearing sleeve slidably mounted on the shaft, said bearing sleeve having a static O-ring which seals the interior of the sleeve to the shaft and a flange which extends into the counterbore;
means radially fixing the bearing sleeve to the shaft;
a ring-shaped seal housing mounted about the bearing sleeve and extending into the counterbore, said seal housing having an interior dynamic O-ring sealing the housing to the bearing sleeve and an exterior static O-ring sealing the housing to the counterbore.

### Claim 2 (depends on 1)

A seal as claimed in claim 1 including:
a retainer ring mounted about the exterior of the bearing sleeve below the ring-shaped seal.

### Claim 3 (depends on 1)

A seal as claimed in claim 1 including:
said body having a second counterbore within the first mentioned counterbore; and
the ring-shaped seal housing being mounted in the second counterbore.

### Claim 4 (depends on 1)

A seal as claimed in claim 1 wherein the means radially fixing the bearing sleeve to the shaft includes:
the bearing sleeve having a tab; and
the shaft having a collar with a cutout for receiving the tab.

### Claim 5 (depends on 1)

A seal as claimed in claim 1 including:
a thrust bearing mounted in the counterbore between the bottom of the counterbore and the sleeve flange for taking the thrust load transferred by the shaft through the sleeve flange.

### Claim 6 (depends on 5)

A seal as claimed in claim 5 including:
a retainer ring mounted in the exterior of the bearing sleeve below the ring-shaped seal.

### Claim 7 (depends on 6)

A seal as claimed in claim 6 including:
said body having a second counterbore within the first mentioned counterbore; and
the ring-shaped seal housing being mounted in the second counterbore.

### Claim 8 (depends on 7)

A seal as claimed in claim 7 wherein the means radially fixing the bearing sleeve to the shaft includes:
the bearing sleeve having a tab; and
the shaft having a collar with a cutout for receiving the tab.