ENME 400: Machine Design Homework Assignment 5 Q. A. A short shaft is connected to a motor shaft through a rigid coupling at one end. It transmits the power received from the motor to a compressor via a belt-pulley combination. It is supported by two tapered roller bearings. The pulley is positioned midway between the two bearings. An axial load P acts on a part of the shaft due to belt misalignment, inducing a compressive stress throughout the affected shaft region located between the pulley and associated bearing. The shaft needs to be designed in this region to withstand the axial compressive stress from P and the torsional shear stress due to the torque T being transmitted. See tables A.1, A. 2, and A.3 for parameter values as needed. Parameter Table A.1. Parameter values applicable for the whole problem. Parameter Value Shaft diameter at the location of 1/2" interest Width of Left Bearing Value 0.4" Width of Right Bearing 0.4" Bearing Span 3" Axial load applied on the shaft at 15 kip the roller-bearing location Torque transmitted T kip.in (unknown) Width of the pulley 0.5" Find: The principal stresses (at the most critical point/s) in terms of T or T (torsional shear stress) (note that we can ignore the effects of transverse shear and bending stresses here) (why?); and T that will just cause failure for the situations provided in parts (a) and (b). To find this value, use a non-conservative failure theory suitable for design of bulk products. (a) Parameter values to be used for this case are provided below. Table A.2. Parameter values applicable for (a). Parameter Syt Syc Sut Suc Value 135 ksi Parameter E Value 30 Mpsi 135 ksi 0.3 180 ksi Ef 0.38 180 ksi