scope:

This part of ISO 10300 specifies the fundamental formulae for use in the tooth root stress calculation of straight and helical (skew), zerol and spiral bevel gears and hypoid gears with a minimum rim thickness under the root of 3,5 mmn. All load influences on tooth 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 to be taken into consideration in the calculation of the tooth root stress óF or the permissible tooth root stress óFP. ISO 10300 is not applicable in the assessment of the so-called flank breakage, a tooth internal fatigue fracture (TIFF). The formulae in ISO 10300 are based on virtual cylindrical gears and restricted to bevel gears whose virtual cylindrical gears have transverse contact ratios of åvá < 2. The results are valid within the range of the applied factors as indicated in ISO 10300-1, and in ISO 6336-3. This part of ISO 10300 does not apply to stress levels above those permitted for 103 cycles, as stresses in that range could exceed the elastic limit of the gear tooth. WARNING: The user is cautioned that when the methods are used for large average mean spiral angles (âm1+âm2)/2 > 45°, large effective pressure angles áe > 30° and for large face widths b > 13 mmn, the calculated results of ISO 10300 should be confirmed by experience.