An automotive-type clutch, as shown in Figure 18.2, has inside and outside diameters of 160 and 240 mm, respectively. Clamping force is provided by nine springs, each compressed 5 mm to give a force of 900 N when the clutch is new. The molded friction material provides a conservatively estimated coefficient of friction of 0.40 when in contact with the flywheel and pressure plate. Maximum engine torque is 280 N m.
(a) What is the safety factor with respect to slippage of a brand new clutch?
(b) What is the safety factor after "initial wear" has occurred?
(c) How much wear of the friction material can take place before the clutch will slip (assuming no change in coefficient of friction)?
