ELECTRO-FLUIDIC COMPONENTS BASED ON SMART MATERIALS FOR AIRCRAFT ELECTRO-HYDRAULIC ACTUATORS

摘要

In the context of a more electrical aircraft, in order to explore the feasibility of non usual solutions, electro-fluidic components based on smart materials and new Electro-Hydraulic-Actuators (EHA) concepts, based on active valves and magnetostrictive vibrating pump, have been studied. Active valves based on different magnetostrictive and piezoelectric actuators have been designed, realised, tested and compared. The magnetostrictive version uses a new Amplified Magnetostrictive Actuator (AMA) based on a stack of Giant Magnetostrictive Materials (GMM) and placed inside an elliptical amplification ring. The piezoelectric version uses a standard amplified piezoelectric actuator APA500L from Cedrat Technologies. The pump is based on a fluid chamber, a piston moving linearly and two channels for inlet and outlet. A large high force magnetostrictive actuator produces the motion. This actuator is made of a GMM rod biased thanks to a serial permanent magnets configuration and excited by a coil. For obtaining a pump from this dynamic pressure generator, two types of valves are considered: either the active valves above mentioned or passive valves. The functioning configurations and the related results are further presented. The active valves combined with the pump offer the advantage of getting a bi-directional pump, which is a useful feature for driving the jack and obtaining directly a compact EHA.