초록 ▼

A fluid swivel is described, of the type that carries oil, water or natural gas at high pressure between an undersea well and a weathervaning ship, which has a seal device of increased lifetime. The seal device (56, FIG. 2 ) lies in a cavity of a first swivel part (12) and includes a rigid seal ring

A fluid swivel is described, of the type that carries oil, water or natural gas at high pressure between an undersea well and a weathervaning ship, which has a seal device of increased lifetime. The seal device (56, FIG. 2 ) lies in a cavity of a first swivel part (12) and includes a rigid seal ring (62) that is slidable toward and away from a sealed surface (66). A deformable seal (60) can be backed up by the seal ring, with the seal ring sliding to close the extrusion gap (70) into which the seal could extrude when high pressure fluid enters the swivel. A pressure source (80) coupled to the cavity urges the backup part to deform radially and slide toward the sealed surface with a force that increases as the pressure of fluid in the swivel increases. Both upstream and downstream ends (89, 99) of the seal ring are closely guided in movement toward and away from the sealed surface, and/or the dynamic side of the seal ring lies closely adjacent to the sealed surface at both its upstream and downstream end portions (180, 194, FIG. 9 ). The seal device can include only the more rigid seal ring (284, FIG. 12 ). The sealed surface (162, FIG. 8 ) can lie on the outer swivel part, with the seal ring being forced by fluid pressure to expand in diameter, rather than contract.

대표청구항 ▼

A fluid swivel which can carry fluid flowing from a pressure source that supplies fluid at a pressure that may reach a high working pressure, wherein the fluid swivel includes inner and outer swivel parts and at least one bearing assembly that pivotally connects said swivel parts so one swivel part

A fluid swivel which can carry fluid flowing from a pressure source that supplies fluid at a pressure that may reach a high working pressure, wherein the fluid swivel includes inner and outer swivel parts and at least one bearing assembly that pivotally connects said swivel parts so one swivel part can pivot about the other, wherein said swivel parts form a fluid-carrying annular chamber between them that is coupled to said pressure source and wherein said fluid swivel forms first and second gap passages between said swivel parts with said gap passages leading from opposite sides of the chamber, with a seal arrangement lying along said second gap passage to seal it and with a first of said swivel parts having a ring-shaped cavity along said first gap passage which holds a seal device and with the second of said swivel parts having a sealed surface lying substantially opposite said cavity, and including a conduit that is coupled to said pressure source and to said seal device to expose said seal device to a fluid pressure which is generally about the same as the pressure of fluid in said annular chamber, where said seal device seals against said sealed surface of the second of said swivel parts, and where said seal device includes a seal ring with portions that can slide within said cavity toward and away from said sealed surface, characterized by: said cavity has upstream and downstream cavity walls each extending toward and away from said sealed surface, and said seal ring has upstream and downstream ends each lying substantially against a corresponding one of said cavity walls to prevent cocking of said seal ring, with said seal ring being slidable toward said sealed surface relative to said first swivel part when said seal device is exposed to a fluid pressure which is about the same as said high working pressure.