摘要 |
An apparatus and method for selecting and controlling the output of a pressure compensated pump during operation is disclosed. The invention comprises a pressure compensated pump having a control inlet for the introduction of a digitally selected reference pressure. Means are provided for producing such a digitally selected reference pressure. Preferably, the means for producing this reference pressure includes a flow regulator for receiving fluid under pressure and establishing a constant pilot fluid flow; a plurality of conduits coupled in parallel to the output of the flow regulator between the flow regulator and a reservoir return flow; and, means individual to at least two of the conduits for controlling fluid flow in proportion to successive digital commands. The control inlet is also connected to the output of the flow regulator, the resulting reference pressure in the control inlet being generated by selected conduit flow areas characterized by the digital commands.
|