GB915850A - Fluid pressure seals for reciprocatory piston rods or plungers, rotary shafts or the like - Google Patents

Abstract

915,850. Stuffing-box substitutes. BELLISS & MORCOM Ltd. Nov. 3, 1961 [Nov. 23, 1960], No. 40233/60. Class 122 (5). A reciprocatory or rotary member 2, such as the plunger of a gas compressor, is sealed by means of a stationary sleeve 7 on which are mounted a number of contiguous collars 8, 9 contained in a cylindrical chamber 5 in a body 1 and each having at one end an annular recess 8a which is formed around the inner periphery of the collar and which contains a sealing ring 14 of rubber or rubber-like material, the sleeve being provided with ports 17 whereby leakage fluid can pass from the clearance between the sleeve and the member 2 to one side of each of the rings 14. The plunger 2 reciprocates in a cylinder 1a in the body 1 provided with gas inlet and outlet 3, 4. A further sealing ring 14 is contained in a recess at the end of the chamber 5 adjacent the cylinder 1a. Each ring 14 is flanked on one side by a metal ring 15 which has equi-spaced pegs 16 extending through holes in the ring and in the next collar. A collar 10 adjacent the collar 9 is formed with an annular recess 12 in which a flange 13 on the sleeve 7 is locked by a cover 6 and with an annular recess 18 in communication with the clearance space between the sleeve and the plunger by means of radial ports 19 and, through passages 20, 21, with a source of low pressure. Lubricant is fed between the sleeve and the plunger through a passage 23, recess 12 and ports 24. Gas leaking past the sealing ring 14 is drained at 22 and returned to the inlet 3. In operation, the rings 14 are compressed into contact with the sleeve 7 by progressively diminishing gas pressure so that the pressures acting on the inner and outer surfaces of the sleeve are practically balanced.