GB762196A - Improvements in and relating to rotary unions for fluid-conveying members - Google Patents

Abstract

762,196. Rotary unions for pipes. MURRAY, W. March 17, 1955 [Dec. 30, 1953], No. 36229/53. Class 99(1) In a rotary union comprising relatively rotatable fluid-conveying members 1, 2 one of which is supported with respect to the other in one or more ball or roller bearings 5, or both, of carbon bearings, and a rotary sliding contact seal including a floating element which is pressed towards a co-operating element on the member 2 and is sealed to the member 1, there is a resilient sealing ring 22 between the element and the member 1, the ring being constructed and arranged to press against the member and the element with a pressure which increases with the fluid pressure, and the element being responsive to the fluid pressure acting against the pressure by which the sealing ring is forced against the element. As shown, the floating element, of close-grained cast iron or carbon, comprises a sleeve 19 surrounding and axially displaceable along the shaft 2, and a collar 18 provided with an axially projecting ring 21 on which a sealing face 20 is formed by lapping. The face 20 contacts a sealing face 17 on the collar 16 provided on the shaft 2 which may be nitrided or of nitralloy. The ring 22 is U-shaped in section and of natural or synthetic rubber or other resilient material and the inner and outer walls of the ring are arranged to be forced against the outer surface of the sleeve 19 and the inner surface of the body 1; the inner surfaces of the walls of the ring diverge from the base 23. A spring 27 is disposed between a spreader ring 24, having converging peripheral faces 25, 26, and the collar 18 to urge the faces 17, 20 into contact and the ring 24 between the walls of the ring 22. The pressure fluid conveyed by the union urges the ring 24 towards the base 23 of the ring 22 and acts behind the collar 18 to urge the latter towards the collar 16 on the shaft 2. Ambient pressure acts of the face 28 of the collar 18 and the area of the collar exposed to the fluid is appropriately chosen to ensure a desired difference in pressure on the opposite sides of the collar. The bearings 5 are spaced by a lantern ring 7 and a ring 6 held in position by a circlip 14 engaging in a groove 15 in the shaft 2, and are lubricated by way of a grease nipple 8. A plug 9 screwed into the body 1 fixes the bearings axially, the inner bearing lying against a plug 10 screwed into the body and abutting a washer 11 and " O " ring 12 which lies against an internal shoulder 13 of the body and prevents fluid leakage along the screw-threads of the plug 10. The shaft 2 has a screw-threaded end 5a for connection to a steam delivery pipe and a pipe for withdrawing condensate from a hollow roll may extend through the shaft. The body 1 may be non-rotatably mounted, yieldingly or otherwise; alternatively the body may rotate and the shaft be yieldingly or otherwise non-rotatably mounted.