Reserves for improving the design of shafts

Shafts are used in almost all machines and mechanisms. Unlike other parts, the destruction of the shafts is very rare. As it was supposed earlier, it is connected with high level of perfection of a technique of their calculation and design. The article analyzes the features of the three traditional methods of shaft design and shows that the shafts are not destroyed for the reason that traditional methods lead to a significant, up to 27 and more times, overestimation of the diameters of all the characteristic areas in comparison with the size sufficient in terms of the strength of the shaft. The area of its cross-section and, accordingly, the mass can be overestimated by more than 750 times. Such unjustified overestimation of the shaft diameter and weight cannot be considered as an indicator of the perfection of the shaft design and calculation methods, and, on the other hand, is an important reserve for the improvement of their designs. This is particularly true for those mechanisms that are subject to increased requirements in terms of minimum size and weight.