摘要 |
<p>A pump powered partly by a mechanical drive and partly by a pressurized fluid flow and comprised of one or more piston-in-cylinder assemblies in which one face of each piston provides a pumping action while a pressurized driving fluid flow is applied to the opposite piston face, thus supplementing the drive force applied to each piston via a piston rod. Input and output of the pumped flow is controlled by pump valves of a non-return poppet type operated by the pumped flow. Input and output of the driving fluid is controlled by poppet-type valves controlled by connection to the pump valves. Piston movement relative to both the cylinder and the piston rod is controlled, and a two-part pump valve is provided to simplify connection to the motor valves.</p> |