In order to accommodate a bearing on an 80mm diameter shaft it is suggested that it be reduced in diameter to 65 mm with a fillet radius of 2.0 mm at the step. The shaft is intended to transmit 45 kW at a speed of 700rpm with torque transmission in one direction only, running continuously during an 8 hour shift. The bending moment at the step is calculated to be 500 Nm. The shaft is subjected to minor shock loads when the load is suddenly applied and is made from CS1030 shafting steel.
Assume the modulus of rigidity, G, = 80 GPa and use FOS = 2.
a) Determine if the small diameter can be further reduced in diameter by calculating the minimum size based on equivalent torque.
b) Determine the torsional deflection of the 65 mm diameter shaft assuming it to be 1 m in length.