Backup ring with controlled spacing
AssigneePolymer Sealing Solutions, Inc.
InventorsJeff Baehl, Larry J. Castleman
Life of this patent
Estimating the term…
Abstract
A backup ring is provided adjacent a seal apparatus for delivering a controlled space between two relatively moving parts. The backup ring provides protection against seal extrusion and failure, and can provide an auxiliary seal when needed. The backup ring includes either an arcuate surface that deforms under pressure, or a cantilever portion that deforms under pressure, or both.
Claims27
A backup ring for providing auxiliary sealing to a primary seal arrangement disposed between a first member having a first contact surface and a second member having a second contact surface, said backup ring comprising:
- a washer having a perimeter in contact with the first contact surface, said washer having a convexly shaped radial cross section, said convexly shaped radial cross section including a first arcuate washer surface and an opposed second arcuate washer surface, one of said first arcuate washer surface and said second arcuate washer surface facing the second surface, said one of said first arcuate washer surface and said second arcuate washer surface extensively contacting the second contact surface only when the seal is pressurized.
A backup ring for providing auxiliary sealing to a primary seal arrangement disposed between a first member having a first contact surface and a second member having a second contact surface, said backup ring comprising:
- a washer having a perimeter in contact with the first contact surface, said washer having a convexly shaped radial cross section, generally arcuate cantilever portion extending from said perimeter of said washer.
A seal arrangement for sealing a gap between a shaft and a housing concentric with the shaft, said seal arrangement having a pressurized state and a non-pressurized state, said seal arrangement comprising:
- a primary seal apparatus disposed within a gland between the shaft and the housing;
- and
- a backup ring disposed between said primary seal apparatus and a wall of said gland, said backup ring extending substantially radially between said shaft and a gland bottom and having a convex portion in the non-pressurized state, said backup ring including a cantilever portion, said cantilever portion extending at an acute angle from the backup ring and disposed between said primary seal apparatus and said gland, wherein said cantilever portion becomes substantially perpendicular to said backup ring plane in the pressurized state, thereby providing a controlled clearance between said shaft and said backup ring.
A method of sealing a gap between a first member and a second member, comprising the steps of:
- providing a primary seal arrangement disposed between the first member and the second member;
- providing a backup ring disposed between the first member and the second member and adjacent said primary seal arrangement, said backup ring having a first backup ring surface adjacent the second member, said backup ring having a convexly shaped portion that deflects when subjected to compressive forces;
- and
- pressurizing the primary sealing arrangement, thereby moving said first backup ring surface, in its entirety, away from the second member.
A backup ring disposed between a first member having a first contact surface and a second member having a second contact surface, said backup ring comprising:
- a washer having a cantilever portion, said cantilever portion of said washer being associated with the first contact surface of the first member, said cantilever portion extending from said washer at an angle from a plane substantially defined by said washer, said washer having a controlled spacing with the second contact surface of the second member, said controlled spacing being based on applied pressure, said cantilever portion moving so as to approach a substantially perpendicular angle from said washer when compressive forces are applied to said backup ring, such said moving of said cantilever portion causing an increase in said controlled spacing.
Dependencies are inferred from the claim text.