The reliability function of hardened cylindrical gears

Abstract

The article describes the shortcomings of existing methods for calculating the reliability function of hardened cylindrical gears according to strength performance criteria (contact fatigue, bending fatigue and tooth flank fracture). A method is proposed for calculating the reliability function of hardened teeth of cylindrical gear wheels according to the contact fatigue criterion, which takes into account the variable value of the misalignment in the gearing caused by the deformation of the shafts, bearing rings and housing (force misalignment). A method is proposed for calculating the fatigue of hardened teeth of cylindrical gear wheels according to the bending fatigue criterion, which uses formulas for calculating the limit of contact fatigue, taking into account the value of the parameters of the hardened layer (effective thickness of the hardened layer). A method is proposed for calculating the reliability function of hardened teeth of cylindrical gear wheels according to the criterion of tooth flank fracture. In all developed methods for calculating the reliability function, the Parzen-Rosenblatt method (nonparametric statistics) is implemented. Based on the proposed methods, software was developed for calculating the reliability function of hardened cylindrical gears (carbonization and carbonitriding). The article presents a qualitative validation of the developed software using information available in the scientific and technical literature on failures of hardened cylindrical gears. It is shown how the method of specifying the force imbalance (constant or variable value) influences the results of calculations of the reliability function of cylindrical gears according to strength performance criteria.