scope:

The formulae in ISO 10300 are intended to establish uniformly acceptable methods for calculating the pitting resistance and bending strength of straight, helical (skew), spiral bevel, Zerol and hypoid gears. They are applicable equally to tapered depth and uniform depth teeth. If in the following text reference is made to all of these gear types, the term 'bevel gear' is used, if not, the specific forms are identified. The formulae take into account the known major factors influencing pitting on the tooth flank and fractures in the tooth root. The rating formulae are not applicable to other types of gear tooth deterioration such as plastic yielding, micropitting, case crushing, welding, and wear. The bending strength formulae are applicable to fractures at the tooth fillet, but not to those on the working flank surfaces, nor to failures of the gear rim or of the gear blank through the web and hub. Pitting resistance and bending strength rating systems for a particular type of bevel gears can be established by selecting proper values for the factors used in the general formulae. If necessary the formulae allow for the inclusion of new factors at a later date. Note, ISO 10300 is not applicable to bevel gears which have an inadequate contact pattern under load (see Annex D). The rating system of ISO 10300 is based on virtual cylindrical gears and restricted to bevel gears whose virtual cylindrical gears have transverse contact ratios of åvá < 2. Additionally, the given relations are valid for bevel gears of which the sum of profile shift coefficients of pinion and wheel is zero (see ISO 23509). 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.