Pump for fluids driven by rods of a material magnetostritivo giant

摘要

In subsea production of oil and gas, a pressurized fluid is needed for operation of valves for the production system. To be able to supply a hydraulic actuator with pressure medium for valve operation without arranging any pressurization from a platform-based pump, a liquid pump has been produced which is driven by rods of a giant magnetostriction material and which may be connected to operating devices and valves at the bottom of the sea. The liquid pump has a high efficiency and has few movable parts. By utilizing the giant magnetostrictive in two alternately operating rods (11) which are arranged in pairs and are surrounded by coils (15) supplied with current, the first rod imparting a movement when magnetic energy is transformed into mechanical energy in the form of a deformation and the second rod dynamically prestressing the first rod together with a load, a piston (12) in a cylinder space (17) of a pump housing (16) may be caused to oscillate for transporting liquid. The giant magnetostrictive material may be an alloy containing the rare earth metals terbium (Tb) and dysprosium (Dy) and iron (Fe), for example Terfenol-D with the stoichiometric composition (TbxDy1-xFe1.9-1.98).