# US 7,744,094 B2 · Mechanical seal device

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- Number: US 7,744,094 B2
- Document ID: US7744094B2
- Status: Granted
- Kind: B2
- Application number: 11/667,166
- Filed: 2005-10-28
- Published: 2007-12-27
- Granted: 2010-06-29
- Earliest claimed: 2004-11-09
- Assignees: Eagle Industry Co., Ltd.
- Inventors: Takashi Yanagisawa; Koji Akiyama; Masanobu Ito; Mami Uchiyama
- Web page: https://patentgrep.com/patent/US7744094B2

## CPC

- F16J 15/3412: {with cavities (F16J15/3424 takes precedence)}
- F16C 17/045: {with grooves in the bearing surface to generate hydrodynamic pressure, e.g. spiral groove thrust bearings}
- F16C 33/1065: {Grooves on a bearing surface for distributing or collecting the liquid}
- F16C 33/107: {Grooves for generating pressure}
- F16C 33/74: of sliding-contact bearings
- F16J 15/342: {with means for feeding fluid directly to the face}
- F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS
- F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS

## Abstract

A mechanical seal device includes a rotational seal ring connected to a rotational shaft, having a rotational seal surface and arc-shaped grooves arranged on the rotational seal surface. The grooves are sectionalized by partition walls. A stationary seal ring has a stationary seal surface facing the rotational seal surface of the rotational seal ring. A spring biases the stationary seal ring against the rotational seal ring. Outlet portions are formed on the stationary seal surface of the stationary seal ring and connect with a fluid supply path for supplying a pressure fluid. A circumferential direction length (W3) of each outlet portion is made to be ½ of a circumferential direction length (W1) of each partition wall or longer (W3≧W1/2); and a circumferential direction length (W3) of the outlet portions is made to be shorter than a circumferential direction length (W2) of the arc-shaped grooves (W3<W2).

## Claims

### Claim 1

A mechanical seal device, wherein a rotational seal ring and a stationary seal ring are arranged to face to each other between a rotational shaft and a housing fit together, comprising:
the rotational seal ring connected to said rotational shaft, having a rotational seal surface, and having a plurality of arc-shaped grooves arranged on said rotational seal surface to be a circular shape around an axis center of said rotational shaft, the grooves being sectionalized by partition walls;
the stationary seal ring having a stationary seal surface facing the rotational seal surface of said rotational seal ring;
a bias means for pressing said stationary seal ring against said rotational seal ring; and
outlet portions formed on said stationary seal surface of said stationary seal ring and capable of connecting with a fluid supply path for supplying a pressure fluid,
wherein said arc-shaped grooves are arranged at positions facing said outlet portions formed on said stationary seal surface,
wherein said outlet portions are arranged at positions forming a circle around the rotational shaft and having an identical radius that is concentric with said arc-shaped grooves, and
wherein a circumferential direction length (W3) of each of said outlet portions is made to be ½ of a circumferential direction length (W1) of each of said partition walls or longer (W3≧W1/2);
the circumferential direction length (W3) of each of said outlet portions is made to be shorter than a circumferential direction length (W2) of each of said arc-shaped grooves (W3<W2).

### Claim 2 (depends on 1)

The mechanical seal device as set forth in claim 1, wherein:
said outlet portions are formed to be wider in the circumferential direction length than said fluid supply path;
the outlet portions are arranged to be an approximately concentric circle with said plurality of arc-shaped grooves on said stationary seal surface;
a circumferential direction length (W3) of each of said outlet portions is made to be longer than a circumferential direction length (W1) of each of said partition walls (W3 >W1) ; and
the circumferential direction length (W3) of said outlet portions is made to be shorter than 1/2 of a circumferential direction length (W2) of said arc-shaped grooves (W3<W2/2).

### Claim 3 (depends on 1, 2)

The mechanical seal device as set forth in claim 1 or 2, wherein said outlet portions are formed to be a circular-shaped or arc-shaped openings.

### Claim 4 (depends on 1, 2)

The mechanical seal device as set forth in claim 1 or 2, wherein said partition walls are formed to be relatively lower than said rotational seal surface and relatively higher than bottom surfaces of said arc-shaped grooves.