Plunger pump having a rotatable plunger with cut face disposed in a cylinder wherein the cylinder includes a main body and a spacer section with the spacer section having a greater length in an axial direction than the maximum stroke length of the plunger

Abstract

Plunger pump includes cylinder having inside cylinder chamber; plunger disposed in cylinder to be relatively movable forward and backward to cylinder chamber so outer plunger's circumferential face is in slide contact with cylinder's inner circumferential face, and having cut face on distal end's outer periphery; and suction and discharge ports provided to cylinder to communicate with cylinder chamber, plunger pump transferring fluid by reciprocating plunger in axial direction while rotating plunger relative to cylinder chamber to let suction and discharges ports alternately communicate with cylinder chamber, wherein cylinder includes cylinder main body and spacer section being disposed in cylinder main body's inner portion of proximal end side, and sliding against plunger's portion closer to proximal end side than portion of plunger advancing and retracting into cylinder chamber, and plunger pump further includes seal section provided on cylinder's proximal end side for sealing cylinder main body, plunger and spacer section.