Rotation shaft seal

Abstract

A rotation shaft seal to prevent inner leak from increasing along high-pressurization of sealed gas. A staged portion is formed on an outer case, and an end face on an inner side of the staged portion is covered with rubber to form a ring rubber portion of which end face is covered. A rubber end face of the rubber portion and a face on a peripheral edge of a seal element are pressed to each other.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described with reference to the accompanying drawings in which:

FIG. 1 is a cross-sectional view of a principal portion showing an embodiment of the present invention;

FIG. 2 is an enlarged explanatory cross-sectional view of a principal portion;

FIG. 3 is a cross-sectional view of a principal portion showing main parts;

FIG. 4A is an explanatory view to show an assembly method;

FIG. 4B is an explanatory view to show a principal portion;

FIG. 4C is an explanatory view to show a principal portion;

FIG. 5 is an explanatory cross-sectional view of a principal portion to explain the assembly method;

FIG. 6 is an explanatory cross-sectional view of the principal portion to explain the assembly method;

FIG. 7 is an explanatory view of a test apparatus as a sample of the present invention and testing method of the same;

FIG. 8 is an explanatory view of a test apparatus as a conventional sample and testing method of the same; and

FIG. 9 is a cross-sectional view of a principal portion showing a conventional example.

Claims

1. A rotation shaft seal provided with a rubber portion having a lip portion to contact a surface of a rotation shaft and an outer case of metal to which the rubber portion is unitedly fixed, comprising a construction in which a rubber end face in an axis-orthogonal direction is composed of a part of the rubber portion and formed on a middle position in an axis direction on an inner face of the outer case, and a face of a peripheral edge of a seal element facing a high-pressure side is press-fit to the rubber end face.

2. A rotation shaft seal provided with a rubber portion having a lip portion to contact a surface of a rotation shaft and an outer case of metal to which the rubber portion is unitedly fixed, comprising a construction in which a staged portion is formed on a middle position in an axis direction on the outer case, an end face on inner side of the staged portion is unitedly covered by a part of the rubber portion to form a rubber end face in an axis-orthogonal direction, and a face of a peripheral edge of a seal element facing a high-pressure side is press-fit to the rubber end face.

3. A rotation shaft seal provided with a rubber portion having a lip portion to contact a surface of a rotation shaft and an outer case of metal to which the rubber portion is unitedly fixed, comprising a construction in which the outer case has a cylindrical wall portion corresponding to an inner peripheral face of a housing, a staged portion is formed on a middle position in an axis direction of the outer case and on the cylindrical wall portion to divide a small cylinder portion on a high-pressure side and a large cylinder portion on a low-pressure side, an end face on inner side of the staged portion is unitedly covered by a part of the rubber portion to dispose a rubber end face in an axis-orthogonal direction as to be directed to the low-pressure side, and a face of a peripheral edge of a seal element facing the high-pressure side is press-fit to the rubber end face.

4. The rotation shaft seal as set forth in claim 1, 2, or 3, wherein a small ridge and a small concave groove are concentrically formed on the rubber end face in unpress-fit state of the seal element, and rubber material of the small ridge is elastically deformed as to flow into the small concave groove by press-fitting of the face of the peripheral edge of the seal element as to keep sealing in press-fit assembly state of the seal element.

5. The rotation shaft seal as set forth in claim 4, wherein an end face-covering ring rubber portion, composed of the part of the rubber portion and covering the end face on inner side of the staged portion, is provided, and an inner member of metal, receiving a high-pressure side of the seal element and an inner peripheral face of the end face-covering ring rubber portion, is attached.

6. The rotation shaft seal as set forth in claim 5, wherein the small ridge is disposed on an inner-peripheral corner portion on the high-pressure side of the end face-covering ring rubber portion, the small concave groove, having a radius dimension larger than that of the small ridge, is disposed near the small ridge, and a peripheral face of the inner member stops inward flowing of the rubber material of the small ridge in radius direction in the press-fit assembly state of the seal element.