1. Design of Shaft References:
Machine Elements in Mechanical Design by Robert L. Mott, P.E. (Chapter 12)

2. Shaft Design Procedure
Determine rpm of shaft
Determine power or torque
Determine part mounted on shaft (gears, belts…)
Determine location of bearing
Determine location of (key, fillets …)

3. Shaft Design Procedure (Cont’d)
Draw torque diagram
Determine forces on shaft
Resolve components of forces in horizontal & vertical plan
Solve the reaction on bearing
Produce S.F. Diagram & B.M. diagram

4. Shaft Design Procedure (Cont’d)
Select material and specify its condition (Suggested material is : AISI 1040, 4140, 4340, 4640, 5150, 6150, and 8650). Then determine
Determine appropriate design stress, considering the manner of loading (smooth, shock…)
Analyze each critical point of shaft then decide which point is safer
Specify the final dimensions

5. Forces exerted on shafts

6. Forces exerted on shafts

7. Helical Gears

8. Bevel Gears

9. Bevel Gears

10. Chain Sprocket

11. V-Belt sheaves

12. Flat-Belt sheaves
Stress Concentration in Shafts

13. When shaft designed according to strength the following cases can be considered:
Shaft subjected to bending only (Axle)
Shaft subjected to torsion only

14. Shaft subjected to torsion & bending

15. Shaft subjected to torsion, bending and axial load

16. For Hollow shaft and combined factors