Fatigue Damage of Gear Teeth in Speed Reducers Moving Heavy Rotors

An analytical investigation was undertaken of the dynamic loading and fatigue of the gear teeth of turbine generator turning gear mechanisms during engagement, using a nonlinear function of speed and load for the coefficient of friction, which was determined experimentally under stick-slip conditions and considering backlash. When heavy rotors are rotating on fluid bearings at low speeds, they are sometimes subject to stick-slip. The fatigue damage resulting in such systems due to the stick-slip self-excited vibrations developed on the bearings, and the backlash of the gear teeth can be predicted by a simulation procedure described in this paper. The effects of some design parameters on the fatigue life reduction and tooth loading are also investigated so that they may be used in design.