| 摘要 |
A pump includes a pump housing (10, 11, 20) that has a circular-cylindrical piston chamber (14), a rotatable and axially movable circular-cylindrical pump piston (40) in said chamber, means (30, 43) for rotationally driving the piston in the chamber, and means (11, 41; 13, 42; 67, 68) for imparting to the piston guided axially reciprocating movement in the piston chamber through the medium of piston rotation, wherein the pump includes lines and valve means for permitting one-way suction and one-way propulsion of pump fluid respectively into and out of the pump chambers between the ends of the piston chamber and the respective adjacent end of the piston. The means for imparting axial reciprocating movement to the piston are adapted to cause the piston to move axially at a constant speed at a constant rotational speed of the piston, at least during the expulsion of pump fluid. |
