Chicago Rawhide Manufacturing Co.

Other

Cr Industries, Inc.

Burton K Olsson

James P Morley

Ellis Larson

The present invention is directed to a grit exclusion and oil retention seal for use in extremely hostile environments. These environments include, but are not limited to sealing oil within cavities forming parts of earth drilling bits and the like. Seals such as these, include the ability to seal oil within a cavity in a reliable manner even under extreme conditions of vibration, mechanical shock, and the presence of grit, sand, water, dirt and mixtures thereof. In order to function properly in this environment, the seal must also provide a certain amount of axial end play so that relative movement of the sealed parts will not permit the seal to leak. In this connection, a heavy duty seal of the type with which the invention is concerned must provide not only a primary or relatively moveable seal, but also a secondary seal. The seal assembly must include means for transmitting torque from the housing or carrier to the primary seal rings. Means must be present for applying and maintaining an axial end face load of the proper range.

Unitized seal for severe service applications

A mechanical end face seal assembly with first and second, relatively rigid, primary seal rings of a generally T-shaped cross-section and a pair of annular secondary elastomeric seal rings. The secondary rings provide a combination of radial compressive load and axial end face load and are of generally parallelogram shaped cross-section. One secondary seal member extends radially outwardly from its associated primary seal ring and the other secondary ring extends radially inwardly from its associated primary ring.

Heavy duty end face seal with asymmetrical cross-section

A seal and sealed mechanism adapted to prevent dirt from entering portions of the seal cavity. The seal includes at least one annular primary seal ring of generally L-shaped cross-section and having a sealing surface formed on one side of the radial flange of the primary ring. An elastomeric secondary seal ring is also provided, with such ring being generally parallelogram-shape in cross-section. The inner diameter of the secondary ring fits snuggly in use over the outer diameter of the axial flange of the primary ring. A dirt excluder lip extends outwardly from one face of the secondary seal ring and covers the end portion of the radial flange of the primary ring to prevent foreign material from entering the cavity between the outer inclined surface of the secondary ring and the end surface of the radial flange of the primary ring. The excluder lip is effective in various axial positions of the seal. The seal may comprise a pair of identical primary and secondary rings in face to face relation. The seal may be incorporated in a sealed mechanism such as a track roller, track pin, or final drive for a crawler tractor or the like.

Mechanical end face seal with dirt excluder lip

An improved rotary end face mechanical seal assembly particularly adapted for intermittent use in severe service environments. The seal comprises at least one relatively stiff primary sealing ring having an axially facing, radially directed end face portion, at least a part of which, in use, engates an oppositely directed member to form a primary seal band area. The primary seal ring includes an at least partially outwardly directed seat for receiving a portion of a secondary sealing and driving member which is made from an elastomeric material, which engages the seat so as to form a secondary seal, to transmit driving torque to said primary seal, and to prevent relative rotation between the primary seal ring and the secondary sealing and driving member. The secondary member also transmits an axial end load to the primary seal face to achieve the primary seal. The primary seal ring contains means forming a lubricant reservoir, so that lubricant may be retained in the area of the primary sealing surface even when the apparatus containing the seals is not in use, and so that, upon starting up, the lubricant will be supplied immediately to the seal faces lying immediately adjacent the seal band area. In a preferred form, the seal assemblies are formed from substantially identical pairs of seal parts, arranged in a mirror image relation.

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Park Ridge, IL, United States of America

Burton K Olsson