Modeling of Chipped Tooth Fault in Straight Bevel Gears

Bevel gearboxes are used when power is to be transmitted at right angles. The application of bevel gears can be found in many industries. Automobile differentials and transmissions of aircraft are the other examples of the application of bevel gears. Gearboxes are designed to operate flawlessly to achieve the desired performance. However, manufacturing defects and propagation of an incipient fault may reduce the reliability of the bevel gearbox and leads to catastrophic failures. Hence, it is imperative to identify the faults at the earliest to prevent premature failures. Gear meshing stiffness (GMS) changes as the fault occurs in gear teeth. Therefore, in this paper, a chipped tooth fault model as a change in GMS of a straight bevel gear pair is proposed. The GMS model of a chipped tooth fault is incorporated in the dynamic model of a one-stage straight bevel gearbox for simulation. Dynamic responses have been calculated, and fault characteristics of the fault have been identified. An experiment has been performed to validate the simulation result. From the comparison of experimental and simulation results, it is shown that the proposed model can identify the chipped tooth fault successfully in a bevel gearbox.