Defines the fundamental formulae for use in the tooth root stress calculation of straight and helical (skew), Zerol and spiral bevel gears including hypoid gears, with a minimum rim thickness under the root of 3,5 m[mn].

This part of ISO10300 specifies the fundamental formulae for use in the tooth root stress calculation of straight and helical (skew), Zerol and spiral bevel gears including hypoid gears, with a minimum rim thickness under the root of 3,5 mmn. All load influences on tooth root stress are included, insofar as they are the result of load transmitted by the gearing and able to be evaluated quantitatively. Stresses, such as those caused by the shrink fitting of gear rims, which are superposed on stresses due to tooth loading, are intended to be considered in the calculation of the tooth root stress, σF, or the permissible tooth root stress σFP. This part of ISO10300 is not applicable in the assessment of the so-called flank breakage, a tooth internal fatigue fracture (TIFF). The formulae in this part of ISO10300 are based on virtual cylindrical gears and restricted to bevel gears whose virtual cylindrical gears have transverse contact ratios of εvα45°, for effective pressure angles αe>30° and/or for large face widths b>13mmn, the calculated results of ISO10300 (all parts) should be confirmed by experience.