MEGN 481: Machine Design
1) he rotating 1050 cold rolled steel shaft shown in the figure below is simply supported at the center of two bearings (denoted by an X) and the only applied load is the constant 7kN load. All dimensions are in mm and all steps in the shaft have a 4mm fillet radius at the base of each step. Use the ANSI recommendations for keyway design. All three locations, A, B and C have a non-steady torque of Tmax=500N-m and a Tmin=400N-m that follows a sin wave (magically). Determine the safety factor for infinite life at locations A, B and C. The shaft is machined, used at room temperature and requires a material reliability of 99.9%. Assume all other correction factors are equal to 0.499 when multiplied together.
2) For the shaft shown below, disregard the diameters noted. You must completely design the section of the shaft enclosed in red. Specifically, you must determine the three shaft diameters (locations marked "b", "a", and the one between). The diameter of the stepped-up shaft between "b" and "a" cannot be greater than 1.25 times the larger of the two ("a" or "b"). You must design to a FoS=2.5. You must determine an appropriate radius for the transition between the smaller shaft diameters and the larger one (locations marked as "A" and "B" only). You must also specify the correct keyway for shaft section "a" (location marked "C"). Inputs to the system and B.C.'s are identical to those stated above in problem 1.
3) What are the maximum, minimum and average power values for the shaft shown below when l = 20, a = 16, b = 18, P = 1000, Tmin = 0 and Tmax = 2000 lbfin if shaft speed is 750 rpm?
