A BELLOWS-DRIVEN MOTION CONTROL SYSTEM USING A MAGNETO-RHEOLOGICAL FLUID

Abstract

A simple control valve using a magneto-rheological (MR) fluid has been proposed and called the MR valve. The MR valve utilizes the apparent viscosity controllability of the MR fluid in the magnetic field and controls high-level fluid power without moving parts. However, conventional MR fluids have high base viscosities to disperse heavy soft iron particles and lose fluid power in pipes. In this study, low base viscosity MR fluids aredeveloped using lightweight ferrite particles and applied to a bellows-driven motion control system. First, four MR fluids are fabricated with different compositions and the basic characteristics are experimentally investigated. Second, a small-sized three-port MR valve using a permanent magnet is proposed and the most suitable MR fluid is selected through theoretical evaluation to minimize the valve size. Third, the three-port MR valve is fabricated and applied to a bellows-driven motion control system.