標準號：IS 12328 Pt.1-1988
發布日期：1990/4/1 12:00:00
實施日期：1999/12/31 12:00:00
適用范圍：1.Covers the bevel gear systems applicable to straight bevel gears. Since the system is applicable to automotive differential gears with some modifications, the modified system is also covered in Appendix A.1.1 Covers recommended tooth proportions for generated straight bevel gears and the same are applicable for other methods of manufacturing such as moulded, precision forged, etc (see Fig. 1 ).1.2 The system covers ratios in common use and adopts symmetrical rack tooth proportions for tooth thicknesses of pinion and gear for approximately equal strength wherever tooth toplands do not exceed a ratio of 1.6 1.1.3 Though basic pressure angle is 20°, other pressure angles, namely 141/2° and 25° are included to facilitate the use of a lower or higher pressure angle.1.4 This standard covers bevel gears with 13 or more teeth in pinion Pinion having less than 13 teeth require modified tooth proportions to avoid undercut.1.5 Practical consideration covers modules from 0 4 to 25 module in the system.1.6 This standard presumes that size and type of bevel gear has been established according to load rating requirement for the application1.7 The system is generalized to cover angular bevel gears operating on shaft angles other than 90°1.8 The system defines the methods of calculation for various blank dimensions and tooth elements.