公开(公告)号：EP0233200B1

公开(公告)日：1991-09-11

申请号：EP86903948.7

申请日：1986-05-28

Applicant: ELF ATOCHEM NORTH AMERICA, INC.

Inventor： LINDNER, Georg, H.

IPC: F04B7/06

CPC classification number: F04B7/06

Abstract: A positive displacement piston pump (110) includes a cylinder (112) having a working end (114), an inlet port (118), an outlet port (120) and a working chamber bounded by the outlet port and the working end; a piston (128) rotatably and reciprocably movable in the cylinder between a retracted position and an extended position, the piston including a free end having a recessed section alternately in fluid communication with the inlet port and the outlet port; a drive motor rotatably and reciprocably driving the piston in the cylinder; a yoke (154) and ball and socket joint (158) pivotally connecting the piston to the drive motor; a base (136) having an upper surface (136a) with an elongated slot (172) below the pivot point of the piston and an arcuate slot (174) adjacent the opposite end of the cylinder; and first and second pivot pins (188, 190) secured to a swivel plate (182) which is, in turn, secured to the cylinder through a vertical column (180), whereby the recessed section is positioned entirely in the working chamber when the piston is at the end of its pressure stroke, regardless of the angle between the piston and the drive motor.