5.18. In Fig. 5-17, the vertical shaft and the pulleys keyed to it may be considered to be weightless. The shaft rotates with a uniform angular velocity. The known belt pulls are indicated and the three pulleys are rigidly keyed to the shaft. If the working stress in shear is 50 MPa, determine the necessary diameter of a solid circular shaft. Neglect Ans. 29 mm bending of the shaft because of the proximity of the bearings to the pulleys. 3kN 1 KN 250mm B 350 mm 50 mm- 1KN 1.25 KN Fig. 5-17