| 摘要 |
This invention relates to small-sized electrohydraulic actuators for use in adjusting aircraft control surfaces. A problem associated with such actuators is that they must be of a light-weight and efficiently packaged design. The present invention is designed to operate at relatively low hydraulic pressures. A balanced, double-acting hydraulic ram (10), connectable between a support (14) and a member to be moved relative to the support, includes a cylinder (18) divided into first and second chambers (20, 22) by a movable piston (19). A pump (26) having high and low pressure ports (38, 40) is connected to the cylinder (18) by first and second conduits (42, 44). A third conduit (48) connects an accumulator (46) to the first and second conduits (42, 44). A valve (52) is positioned in the third conduit (48), and blocks high pressure flow from a high pressure port in the pump to the third conduit (48). At the same time, the valve (52) permits the accumulator (46) to provide leakage makeup flow through the third conduit (48) to the low pressure port of the pump.
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