Active hydraulic control pressure system for adverse g flight conditions

摘要

An hydraulic control system for an integrated drive generator (10) includes in flow series arrangement, a scavenge pump (32), a spool valve (50) and a boost pump (44). When the spool valve detects an interruption in the supply pressure to the boost pump due to an adverse "g" condition, it reconfigures the system to a closed loop system. In this mode, the oil returning from the CVT (14) is re-circulated back to the boost pump instead of back to the scavenge pump. A small accumulator (42) of oil is used to make up for leakage in the system.