Question 3 A centrifugal friction clutch has a driving member consisting of a spider carrying four shoes which are kept from contact with the clutch case by means of flat springs until increase of centrifugal force overcomes the resistance of the springs and the power is transmitted by friction between the shoes and the case. (a) (b) Determine the necessary mass of each shoe if 22.5 kW is to be transmitted at 750 r.p.m with engagement beginning at 75% of the running speed. The inside diameter of the drum is 300 mm and the radial distance of the centre of gravity of each shoe from the shaft axis is 125 mm. Assume a coefficient of friction of 0.25. {5.66 kg } The width of the each shoe, if the angle subtended by the each shoe at the centre of the spider is 60° and the pressure exerted on the shoe is 0.12 N/mm². {101.32 mm }