Flowserve Management Company

Jacobs, Larry

Ferris, Jason

Gray, Christopher

Larry Jacobs

Jason Crawford Ferris

Daryl L Griffith

Steven D DeSmit

Christopher Gray

Anne L Saad

R James Seaman, Jr

An improved mechanical face seal is provided which includes a pair of relatively rotatable seal rings having opposing seal faces. At least one of the seal faces includes a reverse trapezoidal face pattern having a sine wave depth profile wherein individual face features are circumferentially spaced over the seal face. The reverse trapezoidal face pattern serves to generate a hydrodynamic lift which provides a stable separation of the seal faces that permits formation of a fluid film between the seal faces. The individual trapezoidal grooves have a sinusoidal or similarly shaped depth profile wherein the trapezoid shape is arranged with the narrower edge communicating with the high pressure side of the seal, and the wider edge forms a circumferential dam region towards the low pressure side of the seal. Alternatively, the reverse trapezoidal face pattern may also be provided as a primary face pattern on a dry gas seal in combination with a secondary face pattern wherein the faces operate with a controlled gap under normal pressure conditions as well as when the pressure direction across the seal face is reversed.

Mechanical face seal with a reverse trapezoidal face pattern

A mechanical seal face has a significant increase in the ability of the seal to tolerate poor lubrication conditions such as dry running. The mechanical seal employs a thin, non-corrugated flat sheet of flexible thermally conductive graphite material placed between one of the mechanical seal faces and a metal surface such as a metal surface defined by a shaft sleeve or gland serving as a seal ring holder. The graphite sheet is located axially between a back face of the more thermally conductive mechanical seal ring and the metal face holder part. The conductive seal face material preferably is a ceramic or cermet material such as silicon carbide, tungsten carbide, silicon nitride, aluminum oxide, or a metallic material such as stainless steel. Fluid pressure and spring forces are used to create a compressive load between the seal face, graphite sheet, and metal part to maximize continuous contact between the opposed faces of these parts and the opposite sides of the graphite sheet, and heat buildup at contacting seal faces flows away therefrom to the metal part through the thermally conductive sheet.

Upset resistant mechanical seal

Growing community of inventors

Kalamazoo, MI, United States of America

Larry Jacobs