GB626218A - Improvements in or relating to reciprocating pumps for liquids - Google Patents

Abstract

626,218. Reciprocating pumps for liquids. NEW YORK AIR BRAKE CO. Aug. 26, 1946, No. 25479. Convention date, Nov. 5, 1945. [Class 102(i)] In a pump in which pump plungers 29 reciprocate in a circular series of parallel cylinders 22, each plunger having a spill-back port 69, 68 leading from the cylinder to the pump intake and, surrounding the plunger, a spilloack control valve 66 adjustable in unison with the other spill-back valves, the plungers 29 extend through bores in a guide block 14 into aligned bores in a cylinder block 13 across an intermediate chamber 15 enclosed between the blocks and communicating with an intake passage 8, e.g. through a passage 16. A drive shaft 33 carries a swash-plate 35 which drives the plungers 29 and is bored radially at 42 for the passage of oil from a bore 34 in the shaft 33 to the swashplate chamber. The delivery strokes of the plungers 29 are controlled by the spillvalves 66 which are slidable on the plungers by a plate 64 mounted on a shaft 46 adapted to be moved axially by pressure applied against the end of a piston sleeve 47 by the discharged oil fed to it from the discharge chamber 19, through a passage 52 and port 51 in a bush 45 forming the cylinder for the sleeve piston. The piston operates against telescopic springs 54, 56. A relief valve 25 discharges, oil to the intake side of the pump as maximum pressure is approached in the discharge port 9. Should pressure in the port 9 fail, the plate 64 closes the bore 34 and traps oil in the swashplate chamber. The pump is mounted in a two-part housing comprising a body 6 and cap 7. Specifications 580,354 and 588,615 are referred to.