Scoring in spur gear pair (1st report, scoring temperature in case of gear base oil).

The relationship between scoring and temperature and the correlation between gear test results and two cylinder test results were examined with a gear base oil using an IAE type high speed spur gear test rig. In the mixed lubrication state, scoring occurrence is intimately related to the working flank bulk temperature which is not affected markedly by the sliding velocity and the oil jet direction, unlike the maximum contact surface temperature and the integral temperature. The scoring temperature of a spur gear pair can be estimated from the bulk temperature just before seizure in two cylinder tests taking the specific sliding and the sliding velocities at the beginning or the end of gear meshing into consideration. (A)