Hydraulic actuator 202 (e.g. for aircraft landing gear) having an extension chamber 206 and a retraction chamber 208, and a bypass line 222 connecting the two chambers, the bypass line having flow restrictor 224 and a bypass valve 226 (e.g. in series). The valve is only opened during take-off and landing. The valve may further be opened only if requested by an flight crew. A condition sensor (e.g. thermometer) may open the valve only if criteria met (e.g. temperature threshold), measurement may be displayed to flight crew. Flow restrictor may have 4 to 14 mm2 cross-sectional area. A valve status sensor may sense valve position or hydraulic fluid parameter in the bypass line. The bypass line may be external to the hydraulic ram connecting to the hydraulic lines 216, 218, within the wall of the hydraulic ram housing, or within the moveable piston 204.
Hydraulic actuation system
18.06.2025
Patent
Elektronische Ressource
Englisch