The Optimal Selection of Monitoring Parameters for Pitting Damage of Gears Based on Fault Trend Analysis
Tooth pitting in gears is one of the most critical fault modes in gearboxes, and monitoring the increase of tooth pitting damage can avoid great risk to gearboxes. The optimal selection of monitoring parameters in gearboxes can reduce the monitoring cost and improve the reliability on the basis of meeting monitoring requirements. To better track the increase of pitting damage, monitoring parameters should include abundant information of pitting growth in its evolution process. Hence, this paper proposes a novel approach to select optimal monitoring parameters based on fault trend analysis of pitting growth. With the analytical formulations of tooth pitting, the dependencies between damage levels of tooth pitting and the reduction of mesh stiffness can be obtained, then the damage dynamics of the gearbox system due to tooth pitting can be built. Afterwards, the dynamic responses of generalized parameters in the models of pitting levels can be simulated, and their condition indicators can be obtained by using effective signal processing methods. Then, the sensitivities of each generalized parameter to tooth damage can be calculated, and the optimal monitoring parameters can be determined according to the size of sensitivities. The simulation results show that monitoring the acceleration of gear and calculating its kurtosis can effectively track tooth pitting growth.