Experimental studies on magnetorheological brake containing plane, holed and slotted discs

Abstract

Purpose This study aims to design an ideal magnetorheological (MR) brake that exerts negligible frictional torque in the off-state condition and controllable frictional torque in the on-state condition. Design/methodology/approach Silicone-based MR fluid, containing 9 per cent volume carbonyl iron particles, has been synthesized and used. The synthesized MR fluid is advantageous in maintaining low friction losses in off-state conditions. A magneto-rheometer has been utilized to characterize the off-state viscosity of the MR fluid at variable shear rates and shear stress of MR fluids at various magnetic fields. A mechanism to enhance the braking torque in the on-state condition has been designed and developed. An experimental test rig has been developed to capture the torque characteristics of the developed MR brakes. Three different designs of MR discs have been experimented under a magnetic field varying from 0 to 375 kA/m. Experimental results of braking torque under shear and compression modes have been presented. Findings Slotted disc MR brake gives much better torque performance. Originality/value The braking torque results motivate to use the slotted disc MR brake for high torque application.