OPTION 2

A steel shaft is to be designed to support the spur gear and the overhanging worm shown in the

figure. A bearing at A takes pure radial load. The bearing at B takes the worm-thrust load for

either direction of rotation. The dimensions and the loading are shown in figure 4; note that the

radial loads are in the same plane. The shaft rotate al 500 rpm and the machine will work for 12

hours per day.

Make a complete design of the shaft, including a CAD drawing of the shaft showing all

dimensions, fillets radius, groove dimensions and tolerances if required.

Using a commercial catalog select the bearings or journal bearings and modify the shaft

dimensions to accommodate your bearing selection.

Identify the material and its heat treatment (if necessary).

Design the shaft for infinite life and provide the factor of safety for fatigue and yielding.

Determine the lateral deflection of the shaft and the torsional deformation.

Verify your factor of safety by the graphical methods.