An aircraft hydraulic actuation system comprises a supply line carrying pressurised hydraulic fluid, a line returning hydraulic fluid to a reservoir, and a hydraulic actuator moving a load (e.g. door, landing gear, wheel brake). A first hydraulic line 126 supplies a first actuator chamber 118. A second hydraulic line 128 supplies a second actuator chamber 120. A hydraulic fluid flow path 132 connects the first and second lines. A circulation valve 134 (234, figure 8) selectively opens the flow path allowing fluid circulation from the supply to the return lines through the first and second lines (e.g. passing hydraulic fluid through a filter for cleaning). The circulation valve may be a check valve having a cracking pressure or threshold pressure that fluid in first hydraulic line must reach before the valve opens. Alternatively, a control unit (246) may determine actuator reduced performance based on operation speed or a pressure drop and open a command circulation valve (234).
Aircraft hydraulic actuation system
2021-03-10
Patent
Electronic Resource
English
Hydraulic servo actuation system and method for aircraft
European Patent Office | 2024
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