| 摘要 |
<p>A valveless, variable displacement, reversible, fixed dead volume metering pump formed with a cylinder (26) having ports (25, 27) through which to pump fluid. A rotatable piston (24) is in the cylinder (26) with a duct thereon communicable with the ports (25, 27) to transfer fluid to and from the cylinder (26). A drive coupling (12, 14) is provided for the piston. The piston reciprocates in the cylinder while rotating in a timed relation with respect to the ports (25, 27) and the timed relationship is reversible. The relative angularity between the axis of the piston and the axis of the drive coupling (12, 14) is reversible to obtain reversal of fluid flow with the degree of relative angularity determining the volume of luid being pumped. A substantially constant dead-volume is maintained throughout the range of relative angularity between the axes through the use of a pair of floating swivel axes (86, 87) with a cam to restrict one or both of the axes and free the other depending upon direction of relative angular movement of the axis of the piston (24) with respect to the axis of the drive coupling (12, 14).</p> |
