GB479550A - Improvements in and relating to reciprocating pumps - Google Patents

Abstract

479,550. Reciprocating pumps. KOTAKI, T. Dec. 8, 1936, No. 33724. [Class 102 (i)] [Also in Group XXIX] Relates to pumps of the type in which pairs of plungers 16, 17 have a common compression chamber and the separate driving mechanisms of the plungers are connected through a differential 7, which is rotatable in order to vary the out-of-phase relationship of the plungers in accordance with the discharge pressure. The invention consists in the employment of cams 14, 15 for driving the plungers and in causing the pressure-responsive device 25 to act directly on the differential 7. The driving gear comprises a driving shaft 1, which drives a shaft 2 through the differential 7. The cams 14, 15 which drive the plungers, may be mounted on the shafts 1, 2 or, as shown, on shafts 10, 11, which are driven from the shafts 1, 2 through gearing 8, 12, 9, 13. Each cam may drive a number of radial plungers, as shown, the compression chambers being interconnected by means of circular suction and discharge pipes 22, 23. The discharge pipe is connected by means of a pipe 24 to a cylinder 25, containing a piston 28, which is moved by the pressure against the action of a spring 27, adjustable by means of a screw 26. The piston 28 rotates the differential 7 by means of a rack 29 gearing with teeth 30 on the casing. The pipe 24 contains a disc valve with a central perforation providing a slow leak, thus delaying movement of the piston 28 on a fall of pressure. The pump discharge valve 41, Fig. 6, may be provided with heads having oblique grooves, so that the passage of the liquid rotates the valve. When the pump is employed for an hydraulic press it may be combined with a pump for giving a large delivery at low-pressure. High discharge pressure closes the valves of the low-pressure pump and opens a byepass.