摘要 |
A multi-range pressure compensated fluid delivery system gives output flow over at least two pressure ranges. The system comprises a prime mover driven variable displacement pump having an inlet from a source of hydraulic fluid and a delivery outlet. A delivery circuit from the output has at least two work circuits selectively connected thereto. A first of the circuits is operable up to a first pressure and a second of the circuits is operable only up to a second lower pressure. An actuator system controls pump displacement responsive to a pressure applied thereto. A system selectively applies a first signal determined by the first pressure to the actuator system to adjust the operating pressure of the pump. A device reduces the first pressure to the second pressure responsive to connection of the second circuit to the delivery circuit to thereby decrease the maximum compensated pressure setting of the pump.
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