US 5,312,140 A · Fluid swivel structure

Abstract

A fluid swivel is described, of the type which includes a ring-shaped outer structure (12, FIG. 2 ) that rotates about a ring-shaped inner structure (14), and which form an annular chamber (18) between them and a pair of gap passages (24, 26) between them which are sealed by pressure seals (30, 32). The outer structure includes a body (70) forming part of the annular chamber and a seal ring (72) mounted on an end of the body and abutting one side of the pressure seal. The seal ring is axially shiftable on the end of the body, so that when the body expands radially as a result of high pressure fluid being introduced into the annular chamber, the seal ring does not have to expand a similar amount and therefore does not have to cause a large increase in the width of the extrusion gap (62) at the downstream end of the pressure seal. A centering mechanism (110) urges the seal ring to remain substantially centered on the body, and can be formed by a ring of compressible material lying between shoulders (120, 122, FIG. 3 ) respectively on the body and on the seal ring, or can be formed by leaf spring portions (154, FIG. 5 ) of one of the parts. Registers (180, 182) on the seal ring and on the body can engage each other to assure concentricity when the body has expanded a predetermined amount under a predetermined high pressure of at least 50 atmospheres in the annular chamber.

Claims20

Dependent claims

A high pressure fluid swivel with inner and outer structures and at least one bearing rotatably connecting said structures to hold them together and enable them to rotate with respect to each other about an axis, said structures forming an annular chamber between them and at least one gap passage between them extending from at least one side of said chamber, and said swivel has at least one redial pressure seal along said gap passage which has opposite sides bearing respectively against said inner structure and said outer structure, characterized by:

a first of said structures includes a first body forming part of said chamber and having a first end with said gap passage extending to said body first end, said first structure also including a first seal ring which bears against one side of said pressure seal to seal thereto and which forms one side of the gap passage portion lying immediately downstream of said pressure seal, said first structure also including a connecting device that connects said seal abutting ring to said body end but which allows said seal abutting ring to shift with respect to said body end in a radial direction with respect to said axis to enable differential expansion of said body and said seal abutting ring when there is a large change in fluid pressure in said annular chamber.

A method for operating a fluid swivel which has inner and outer structures and at least one bearing rotatable connecting said structures to enable said outer structure to rotate about said inner structure, wherein said structures form an annular chamber between them, at least one gap passage between them extending from at least one side of said chamber, and at least one radial pressure seal along said gap passage which has opposite sides bearing respectively against said inner structure and said outer structure, characterized by:

constructing a first of said structures with a body that forms part of said chamber and that has a first end to which said gap passage extends, and with a separate seal abutting ring that lies substantially against said body end, wherein said seal abutting ring bears against one side of said pressure seal and forms one side of the portion of said gap passage lying immediately downstream of said pressure seal;
said step of constructing including mounting said seal abutting ring on said body end to enable said seal abutting ring to shift radially thereon, to thereby enable less radial expansion of said seal abutting ring than of said body when there is a large change in fluid pressure in said annular chamber.

A fluid swivel comprising:

ring-shaped inner and outer structures, said outer structure surrounding said inner structure, said structures forming an annular chamber therebetween and a pair of gap passages extending from opposite sides of said annular chamber;
first and second radial pressure seals, each disposed along one of said gap passages and having radially opposite sides seal to different of said structures to block fluid flow through a corresponding one of said gap passages;
a bearing connecting said structures to allow said outer structure to rotate about a vertical axis with respect to said inner structure;
at least one of said structures includes a body forming part of said annular chamber with said body having opposite ends spaced apart parallel to said axis, two seal abutting rings each lying at a different one of said body ends and engaged with one of said sides of one of said pressure seals, and a connector connecting each seal abutting ring to a corresponding body end with each of said seal abutting rings being radially shiftable on the corresponding body end;
said body of said one structure having a radially facing body register at each of said body ends thereof, and each of said seal abutting rings of said one structure having a radially facing register facing a corresponding one of said body registers;
each corresponding pair of said registers being slightly radially spaced apart, to abut each other and thereby position each of said seal abutting rings concentric with said body, only after said annular chamber contains fluid at a predetermined fluid pressure which is at least 50 atmospheres.

3 more elements

Dependencies are inferred from the claim text.

Fluid swivel structure

Life of this patent

Fluid swivel structure

Life of this patent

Abstract

Claims20