Tribotest journal 3-2

Abstract

Abstract Keywords static friction, brake, testing, materials, properties, time-dependence, creep lNTRODUCTlON Two basic functions are essential for any friction brake in mechanical systems: the first is to provide controlled deceleration; the second, equally important, function is to keep the mechanical system in the rest position as long as required. The latter function is particularly important in installations such as cranes, elevators and mining winding machines, since rapid changes of torque take place as a result of the unloading and loading actions during the rest period. The values of static friction forces are crucial in maintaining the rest position of the mechanical systems. The static friction forces, on the other hand, are determined by the coefficient of static friction and the clamp forces on the brake shoes