GB973625A - High pressure fluid seals - Google Patents

Abstract

973,625. Seals. CATERPILLAR TRACTOR CO. June 5, 1963 [June 21, 1962], No. 22306/63. Headings F2B, F2G and F2T. A sealing device between two relatively movable machine elements 13, 14a, Fig. 2, comprises a sealing ring 22 disposed between the elements so as to be fixed with respect to one and in abutting contact with the other and a rigid back-up ring 24 adjacent the ring 22 and disposed at a sufficiently close distance from the machine element which the ring 22 abuts so as to prevent extrusion of the latter, a peripheral surface of the back-up ring 24 being at a distance from an axially extending annular surface of the member with respect to which the ring 22 is fixed so as to be free to float with respect to the machine element which the ring 22 abuts. The members 13, 14a are respectively the rotatable and the stationary parts of a rotary joint. The sealing ring 22 is of P.T.F.E. and is fixedly located in a recess 21 in the member 13 being surrounded by a deformable rubber ring 23 which is located against the bottom 27 of the recess and due to its resiliency urges the ring 22 radially inwards against the member 14a. The back-up ring 24, which is of metal, is journalled approximately one to two thousandths of an inch radial free fit on member 14a and is capable of radial movement relative to the bottom 27 of the recess due to the flexibility of the ring 23. Fig. 2 shows a composite piston slidable in a cylinder 20 and having a pair of sealing rings 22a each of which is provided on each side with a back-up ring 24a.