Shaft design for steady torsion and fully reversed bending Problem: Design a shaft to support the attachments shown in the figure with a design safety factor of 2.5. Given: A preliminary design of the shaft configuration is shown below. It must transmit 2 hp at 1725 rpm. The torque and the force on the gear are both constant with time. Extra information given: Faz=-24.36 lbf, Fay = 8.87 lbf, F, = 30.45 lbf, F₂ = 6.09 lbf, and the torque for 2<x<6.75 in. is T = 73.1 lb.in. Assumptions: There are no applied axial loads. Steel will be used for infinite life. Assume a stress-concentration factor of 3.5 for the step radii in bending, 2 for the step radii in torsion, and 4 at the keyways. The diameter of the shaft is less than 2 in. p-20 15 9-6.75 1=65 b=5 3.5 plane of F 1.5 ap ring R1z key shaft bearing gear frame plane of Fi and F 1.5 R2z not to scale R₂ Ry