Durametallic Corporation

John Crane-houdaille, Inc.

Josef Sedy

Glenn G Pecht

Jon B Hamaker

Donald E Amundson

Artur Zobens

Non-contacting spiral groove face seal for shafts rotating at high pressures and high speeds with combination of two groove patterns on one of the two sealing faces of mating sealing rings; one pattern relatively deep, the other relatively shallow. The relatively deep spiral-shaped groove pattern is optimized for hydrodynamic operation and on shaft rotation pumps the sealed fluid in-between sealing faces to set the running clearance. The relatively shallow pattern is designed to prevent a friction lock of the sealing faces hydrostatically at starts and stops of shaft rotation by admitting controlled amount of the sealed fluid between the sealing faces when the shaft is at or near to a stationary condition.

Spiral groove face seal

A non-contacting grooved face seal for a shaft rotating at a high pressure and high speed with a combination of two groove patterns on one of the two sealing faces of mating sealing rings; one pattern being relatively deep angled grooves, and the other pattern begin a relatively shallow annular groove. The relatively deep groove pattern is optimized for hydrodynamic operation and on shaft rotation pumps the sealed fluid between the sealing faces to set the running clearance. The relatively shallow pattern is designed to hydrostatically prevent a friction lock of the sealing faces at starting and stopping of shaft rotation by admitting controlled amount of sealed fluid between the sealing faces when the shaft is at or near to a stationary condition.

Face seal with angled grooves and shallow annular groove

A non-contacting face seal assembly for a shaft rotating at high speed with an improved secondary seal for low axial drag force. The secondary seal comprises an O-ring with a compliant spring element at its outer circumference. The compliant spring provides a controlled radial force, which keeps the secondary seal in a more reliable sealing contact with the seal ring and the seal housing surface but avoids excessive radial forces so that low axial drag forces due to secondary seal displacements are generated to prevent sealing face hang-up.

Secondary seal for non-contacting face seal assembly

A mechanical seal assembly for creating a sealing relationship between a housing and a shaft which is rotatable relative thereto. The seal assembly includes first and second seal rings having axially adjacent and opposed flat seal faces for creating an annular sealing region therebetween. A driving member is nonrotatably secured to the shaft and positioned in close proximity to the second seal ring, and a plurality of resilient drive connectors cooperate between the drive member and the second seal ring in angularly spaced relation therearound for effecting synchronous driving rotation of the second seal ring in response to rotation of the shaft. The resilient drive connector includes first and second concave walls formed respectively on the drive member and the second seal ring, and a coil spring disposed within and at least partially confined by each of the first and second concave walls so that each of the concave walls engages at least several coils of the coil spring for transmitting rotatable driving force from the drive member through the coil spring to the second seal ring.

Mechanical seal with spring drive

Non-contacting seal for shafts rotating at high speeds with improved centering means for low unbalance of seal rotating parts. Centering means comprise a shallow circumferential groove with slanted sides and an elastic centering strip of ladder-like form between two cylindrical surfaces to be held concentric. Since slanted sides of the groove overlap sides of the centering strip it cannot be displaced out of its groove during assembly, or during operation. Displaced centering strip could cause unbalance, vibrations, damage to the seal or to the surrounding equipment.

Non-contacting seal with centering spring mounted in dovetailed grooved

A fluid seal of the type employing a groove pattern on one of the opposed seal faces, which groove pattern includes a series of angled grooves formed in and positioned circumferentially around one of the seal faces, with the configuration of the grooves and of the flat face lands defined between adjacent grooves being configured to improve the squeeze film effect over the lands and between the opposed faces. The angled grooves are formed such that the sides of adjacent grooves extend generally in parallelism with one another so that the intermediate land area between adjacent grooves maintains a substantially constant width, even adjacent the radially inner ends of the grooves.

Face seal with angled grooves

Fluid film seal for shafts rotating at high speeds with improved centering means for low unbalance of the rotating seal ring. Centering and drive means are combined and interspaced at the center portion of the outer diameter of the symmetrical rotatable seal ring. The drive and centering at the outer ring diameter direct drive and centering forces inward, lowering tensile stresses due to centrifugal forces. Symmetry of the rotatable seal ring cross-section makes also centrifugal stresses symmetrical with no resulting torsion around the ring cross section to cause face distortions and yields an alternate seal surface at the back side of subject seal ring.

Fluid film seal

A non-contacting face seal for shafts rotating at high speeds with improved secondary sealing means for low axial drag forces. Secondary sealing means comprise an O-ring with a compliant spring element at its outer circumference. Compliant spring provides a controlled radial force, which keeps the secondary seal in a more reliable sealing contact with the seal ring and the seal housing balance surface but avoids excessive radial forces, typical for secondary seal located between two machined cylindrical surfaces. Low axial drag forces due to secondary seal displacements are important for prevention of sealing face hang-up and consequent high leakage condition.

Non-contacting face seal

A seal system is disclosed for sealing a housing and rotatable shaft against leakage of high vapor-pressure liquids. The method of sealing contemplates phase change of the liquefied hydrocarbon fluid across a first module. The gas so formed is contained by a second seal module which operates as a dry running gas seal. The seal system has plural, axially spaced spiral-groove seal modules mounted between the shaft and housing. Each seal module has a primary ring affixed to the housing and a mating ring affixed for rotation with the shaft and the modules define an intermediate cavity. The rings have opposed, radially extending faces, one of which has a plurality of downstream pumping spiral grooves extending from one circumference. The grooves of the grooved ring of the upstream module are of a depth not to exceed about 100 micro-inches. In a preferred form, the depth of the grooves of the upstream module do not exceed 50 micro-inches. The groove depth of the grooves of the downstream module is greater than the depth of the grooves of the upstream module and may be as much as 200 micro-inches.

Growing community of inventors

Mount Prospect, IL, United States of America

Josef Sedy