Actuator cooling flow limiter

An actuation system, comprising:

• an actuator comprising a piston and a housing cooperatively defining first and second interiors on extend and retract sides of the piston,
• the housing further defining a main line by which the first and second interiors are fluidly communicative;
• a fluid source;
• a remote servo valve fluidly interposed between the actuator and the fluid source,
• fluid supplied from the fluid source being exclusively provided to the first and second interiors from the remote servo valve;
• and
• a flow circuit coupled to the main line and having a variable flow area through which fluid is permitted to flow between the first and second interiors,
• the variable flow area being variable in response to a pressure differential between the first and second interiors,
• wherein the flow circuit comprises first and second sections of the main line, an orifice disposed along the main line between the first and second sections, a bypass line fluidly coupled to the first and second sections at opposite ends thereof, respectively, and a bypass valve disposed along the bypass line between the opposite ends thereof and having a variable valve flow area which is responsive to a pressure differential between the first and second sections, and
• wherein the bypass valve comprises a first valve opening which is fluidly coupled to one end of the bypass line, a second valve opening which is fluidly coupled to the other end of the bypass line, a valve element and springs by which the valve element is anchored to the first and second valve openings and by which the valve element is elastically biased to move between open and closed positions relative to the first and second valve openings in response to the pressure differential.

A gas turbine engine actuation system, comprising:

• an actuator comprising a piston and a housing cooperatively defining first and second interiors on extend and retract sides of the piston,
• the piston being movable between extend and retract positions responsive to pressures within the first and second interiors, and
• the housing further defining a main line by which the first and second interiors are fluidly communicative;
• a pump;
• a remote servo valve physically displaced from the housing and fluidly interposed between the actuator and the pump,
• fluid supplied from the pump being exclusively provided to the first and second interiors from the remote servo valve;
• and
• a flow circuit coupled to the main line and having a variable flow area through which fluid is permitted to flow between the first and second interiors,
• the variable flow area being variable in response to a pressure differential between the first and second interiors,
• wherein the flow circuit comprises first and second sections of the main line, an orifice disposed along the main line between the first and second sections, a bypass line fluidly coupled to the first and second sections at opposite ends thereof, respectively, and a bypass valve disposed along the bypass line between the opposite ends thereof and having a variable valve flow area which is responsive to a pressure differential between the first and second sections,
• wherein the bypass valve comprises a first valve opening which is fluidly coupled to one end of the bypass line, a second valve opening which is fluidly coupled to the other end of the bypass line, a valve element and springs by which the valve element is anchored to the first and second valve openings and by which the valve element is elastically biased to move between open and closed positions relative to the first and second valve openings in response to the pressure differential.