Effect of the ISO 6336-3:2019 Standard Update on the Specified Load Carrying Capacity Against Tooth Root Breakage of Involute Gears

摘要

The ISO 6336 series of standards contains a verified specification for calculating the strength of involute gears. Updates issued in November 2019 contain more detailed calculation methods based on the latest research findings. Of particular interest here is Part 3 (Ref. 1), which focuses on the tooth bending strength of spur and helical gears and provides a safety factor against tooth root breakage. Following the update of the previous 2006 version (Ref. 2), the revised standard from 2019 (Ref. 1) can yield a higher or lower safety factor depending on the specific gear design. Consequently, to enable an optimal gear design, the gear engineer needs to be aware of the effects of the changes in the standard on the overall result of the calculation.