GB966561A - Improvements in or relating to combinations of two relatively reciprocating coaxial elements - Google Patents

Abstract

966,561. Compressors. PHILIPS' GLOEILAMPENFABRIEKEN N.V. April 5, 1961 [April 8, 1960], No. 12182/61. Heading F1N. [Also in Division F2] A seal is effected between two relatively reciprocating co-axial elements e.g. a movable rod 10 and a stationary vertical sleeve support 11a, 11b, Fig. 1, by a metal sleeve 15 of substantially rectangular longitudinal section having a length equal to at least three times its thickness which engages one element 10 and is engaged by one or more elastic rings 17 accommodated in the other element 11a, 11b, the periphery of the sleeve being subjected to a complex of forces which are directed towards the element 10 in a zone located asymmetrically of its length and are so proportioned that, under the action of a pressure produced in a fluid located between the sleeve 15 and the element 10 as a result of relative movement between the elements, the sleeve is elastically deformed against the action of the applied forces. The sleeve serves to separate from each other spaces A, B, containing respectively a high pressure gas and a low pressure gas and oil. Springs 14 mounted on a ring 13 exert on a shoulder 15b formed at the lower part of the sleeve facing the space B a uniformly distributed force greater than that exerted radially on the remainder of the sleeve by the high pressure gas. During upstroke of the rod 10 oil carried by it will be arrested by the sleeve. On the downstroke any oil having leaked past the sleeve towards the space A is, as a result of the rod movement, forced in a wedge-like manner between the sleeve and the rod and pumped back towards the space B. The sleeve 15 is of white metal and may have a nylon lining. In a modification, Fig. 2 not shown, the force exerted on the lower part of the sleeve is produced by the pressure of a medium fed through channels in the sleeve support. In a further modification, Fig. 4, the greater force is exerted on the top part of the sleeve facing the higher pressure space A so that, on the upstroke of the rod, oil, or gas if the space B contains only gas, is carried past the sleeve towards the high pressure space whilst, on the downstroke, high pressure gas is prevented from reaching the space B. In a still further modification, Fig. 5 two sleeves separated by a space C are arranged in the sleeve support, the upper sleeve 52 acting as an oil arrester and the lower sleeve as an oil pump so that oil is carried into the space C and provides a liquid seal preventing leakage of gas from the high pressure space A to the low pressure space B. A spring-controlled safety valve 71 is provided in the sleeve support to prevent excessive rise in the oil pressure in the space C. The Specification states that the sleeve may be mounted in a piston movable in a cylinder.