Abstract: A system for cooling individual integrated actuator packages (IAPs) positioned throughout the aircraft in a power-by-wire actuation system is disclosed. A low-pressure hydraulic fluid circulates throughout the aircraft to control the temperature of the individual IAPs and to maintain and replenish the hydraulic fluid within the individual IAPs. A thermo-control loop containing low-pressure hydraulic fluid includes a pump, low-pressure hydraulic lines, a heat exchanger, a reservoir and a filter. The entire system provides heat transfer for a high- or low-temperature environment, as may be present on an aircraft. The individual IAPs may be coupled together in series or, alternatively, in parallel, depending upon the design constraints of the system. Compared with distributed hydraulic systems, energy consumption, weight, and cost are significantly reduced by using a low hydraulic pressure for the circulating fluid. Survivability is significantly increased over that provided by a distributed hydraulic system.

Abstract: A hydraulic system pressure fluid accumulator apparatus is disclosed that meets peak load demands beyond the flow capacity of the system pump. Gas cylinder actuation of the accumulator piston augmented by system pressure feedback actuation of the piston metered by a pressure regulator valve maintains accumulator output pressure level substantially independent of piston displacement.