Numerical Problems: - Design a cast iron protective type flange coupling to transmit 15kW at 900r.p.m. from an electric motor to a compressor. The service factor may be assumed as 1.35. The following permissible stresses may be used:- Shear stress for shaft, bolt and key material = 40MPa Crushing stress for bolt and key = 80MPa Shear stress for cast iron = 8MPa Draw a neat sketch of the coupling.