An axial clutch has to transmit rotation of 2000 rpm with a

An axial clutch has to transmit rotation of 2000 rpm, with a torque capacity of 40Nm. The friction surfaces have a coefficient of friction of 0.15, maximum allowable velocity of 24 m/sec, maximum allowable pressure of 800 k Pa and PV rating of 2 M Pam/sec. The outer diameter of the friction disks is not more than 24 cm and the inner diameter is not less than 18cm. For a safety factor of 1.2, find the (minimum) needed number of pairs of friction surfaces. What are then the internal and external diameters if a minimum actuating force is required? What is then the actuating force?

Solution

The reliability of the station must be 0.995 at the end of the first year.

a) Determine the percentage increase in reliability for each of the major subsystems needed in order to reach the system goal. Assign equal reliability goal to all subsystems.

b) If redundancy is the only means of achieving further reliability growth for each of the subsystems, what is the minimum number of redundant units of each necessary to achieve the component reliability goals?