| 摘要 |
A rotary reciprocating sub-assembly for pumping a fluid, the sub-assembly comprises: a hollow body provided with two ducts; and a piston that co-operates with the body to define a working chamber, the piston being movable angularly between two fluid-flow configurations and switching configurations, and being movable in reciprocating longitudinal translation so as to cause the dimensions of the working chamber to vary, the ducts are longitudinally offset from each other, the piston includes a channel that opens out longitudinally into the working chamber and radially into a pair of side recesses that are longitudinally offset, and that are arranged so that, in each fluid-flow configuration, only one of the recesses is in fluid-flow communication with only one of the ducts. |
