GB902668A - Pumping apparatus - Google Patents

Abstract

902,668. Reciprocating pumps. HYDRAULECTRIC ENTERPRISES Ltd. Nov. 22, 1960 [Nov. 23, 1959], No. 39708/59. Class 102(1). A reciprocating pump 3 in which an eccentric 215 and tappet or tappets 219 for reciprocating the radial piston or pistons 216 have a lost motion connection therewith and a compression spring 221 is provided in each piston tending to move it always in the direction in which it delivers liquid through the outlet passage 208, Fig. 2 (not shown). Liquid is supplied to the reciprocating pump 3 by a continuous delivery gear wheel pump 2 through a passage 4, which is also connected through a pressure regulating relief valve 5 to a reservoir 1. From the reciprocating pump, liquid is supplied through ports 76, 74 of a pressure reducing valve 50 to the larger end chamber 15 of the valve 5 at a constant pressure, and also through a pipe 3<SP>1</SP> to the smaller end chamber 14 of the valve at a varying pressure. When the pressure in the pipe 3<SP>1</SP> exceeds double the constant pressure, the double ended piston 8, 9 moves to the left and allows some liquid from the passage 4 to by-pass to reciprocating pump and be fed to the reservoir through ports 18, 19 of the valve 5 resulting in the maintenance of a steady delivery pressure to load through the pipe 3<SP>1</SP>. Excess delivery to the reciprocating pump 3 is by passed to the reservoir 1 through a spring loaded relief valve 100. The stroke of each piston 216 is variable and determined by the initial movement inwards of the piston, compressing the spring 221 by pressure exerted on the piston crown from liquid in the inlet passage of the reciprocating pump. The cam and bearings of the pump 2 are lubricated from the pressure side thereof, through a restricter 232, Fig. 3A (not shown) leading to the central chamber 203 of the pump 2.