Study of a magneto-rheological grease (MRG) clutch

摘要

In this study the performance of various magneto-rheological (MR) greases in a clutch is examined. An experimental study is conducted to determine the torque transfer capacity of a double-plate clutch for operating speeds up to 1,200 rpm. Six different MR greases with various particle loadings and particle sizes are evaluated in the clutch. The rheological properties of MR grease with 90% particle loading in weight are compared with a commercially available MR fluid. The torque performance of the MR grease clutch is also compared with that of the clutch using MR fluid . It is demonstrated that, the off-state (no applied magnetic field) torque output of the MR grease clutch is constant regardless of the operating speed. In contrast, the torque capacity of the clutch with MR fluid shows a great dependence on the operating speed. Moreover, it is shown that the iron particle size of the MR grease does not affect the torque output. The MR greases demonstrated up to 75% increase in the torque capacity compared to the commercial MR fluid.