| 摘要 |
A reciprocating and rotary subassembly for positive displacement pumping of a fluid includes a hollow body provided with through ducts, a piston received in the cavity, with which it co-operates to define a working chamber, the piston having a recess in fluid-flow communication with the working chamber, and being suitable for being moved in reciprocating and rotary manner to place or not to place the recess facing a duct and to cause the volume of the working chamber to vary, and a sleeve provided with through orifices, interposed between the piston and the body, and suitable for taking up different successive fluid-flow configurations in each of which each duct is selectively closed or open. A reciprocating and rotary pumping device includes such a reciprocating and rotary subassembly, drive means, and mechanical coupling means. |
