Reliability of oversized spindle shafts

Quantify the effect of spindle-shaft diameters exceeding the h5 tolerance band on the long-term reliability of the spindle-shaft and needle-roller-bearing subsystem.

Background

The functional requirement examined in the case study imposed a minimum diameter based on stiffness, while shafts below that threshold could be routed to additive reprocessing. The experiments did not quantify the reliability consequences of diameters above the h5 band, which may alter bearing fit and contact conditions.