Evolutionary Design of Magneto Rheological Brake for Two Wheeler

Abstract

The proposed brake consists of multiple rotating discs immersed in Magneto Rheological Fluid and an enclosed electromagnet. When current is applied to electromagnet, Magneto Rheological Fluid solidifies as its yield stress varies as function of magnetic field. This controllable yield stress produces shear friction on rotating disc which generates braking torque. The braking torque value depends upon number of parameters like Current, Rotor Radius, Surface Area, Number of discs, Gap Size and Angular velocity. In order to minimize the stopping distance to 30cm at response time of 0.5 sec, the brakes need to generate maximum torque up to level of 321 N-m to have maximum braking effect. It is required to optimize the values of above parameters to get minimized stopping distance. Three configurations of Magneto Rheological brake are created and then for each configuration surface area is investigated then its effect on yield stress produced is investigated and then finally braking torque is calculated. Performance in terms of braking torque is evaluated then configuration which producing maximum torque is selected. It is found that brake having ring configuration shows maximum braking effect also it has advantage of compact size which is best suited for two wheeler application. Ring configuration Magneto Rheological Brake shows 10cm stopping distance at 0.23 stopping time which is far better than existing drum type brake.