Basic Studies on Scoring of Spur Gears : 1st Report, On the Seizure under a Pure Sliding Condition and a Sliding-Rolling Condition

Abstract

On a heavy load high speed gear, it seems that the combination of surface pressure and high sliding velocity causes a failure of oil film which leads to a scoring. The pV formula, pVT formula and the surface temperature formula of tooth surface have been used for the determination of scoring limit. But a final formula of scoring limit hasn't been obtained. Using a four ball tester for the basic study of scoring under a pure sliding condition and an Amsler's metal abrasion tester for the study of scoring under a sliding-rolling condition, the authors examined the combined effect of the sliding velocity and sliding ratio on scoring limit. Authors obtained a general formula of surface temperature in the case of an elastic, perfectly plastic solid and compared the formula with the experimental results. Then, they obtained the following results : On a high chromium steel, when the surface temperature was raised to a constant value, a scoring took place. Therefore, it is reasonable to determine the scoring limit from the standpoint of the surface temperature.