New calculation method of the micropitting load carrying capacity of bevel and hypoid gears

Abstract

A frequently observed phenomenon on highly stressed bevel and hypoid gears is micropitting. In contrast to cylindrical gears, where the micropitting load carrying capacity can be determined acc. to ISO/TS 6336-22, up to now no practical calculation methods for rating the micropitting resistance of bevel and hypoid gears are available. Within a research project focusing on the micropitting load carrying capacity of bevel and hypoid gears, comprehensive experimental investigations were carried out. Beside the investigation of the surface roughness and of different types of lubricant, a systematic variation of the hypoid offset was conducted to determine its impact on the micropitting load carrying capacity. Based on the results of the performed experimental investigations, a simplified method (based on ISO 10300-series) as well as a local approach for calculating the micropitting load carrying capacity of bevel and hypoid gears have been developed. The comparison of the results of the experimental investigations and the results of the local calculation method proves a good correlation for the calculated local safety factors and the damaged flank areas in the test.