High-pressure plunger pump with coaxial pressure and suction valves

Abstract

A high-pressure plunger pump includes a pump housing centered on an axis and including a main body having two axially spaced ends, and a pump head secured to one of the ends of the main body. A plunger coaxially extends into the pump housing and a sleeve is floatingly supported on the plunger. The sleeve has two end portions one of which is closer to the pump head than the other, converges toward the pump head and has an axial end face. An insert body is positionally secured in the pump housing at the one end portion of the sleeve and bounds a circumferentially extending annular suction channel with this one end portion. The insert body includes an annular shoulder having a substantially axially facing seating surface. Pressure and suction valves are coaxially arranged within the housing. The suction valve is constructed as a plate valve including an annular suction valve member movable toward and away from its closed position in which its outer and inner regions respectively sealingly contact the annular shoulder of the insert body and the axial end face of the sleeve. A spring urges the suction valve member towards its closed position. The contact surfaces of the inner and outer regions of the suction valve body with the sleeve and with the insert member may be axially offset from one another, and the suction valve member may have a tapered region between such surfaces.