1、IDC 621.833.38 DEUTSCHE NORM Mav 1977 4 5 6,3 8 10 12,5 16 20 - - DIN 780 Series of modules for gears Part 2 Modules for cylindrical worm gear transmissions Modulreihe fr Zahnrder; Moduln fr Zylinderschneckengetriebe This standard, together with DIN 780 Part 1, supersedes DIN 780 As it is current pr
2、actice in standards published by the International Organization for Standardization (ISO), the comma has been used throughout as a decimal marker. This standard applies to cylindrical worm gear transmissions of all kinds, e. g. to transmissions used in precision mechanics, in general mechanical engi
3、neering and in the heavy engineering industry. The modules listed in the table shall prevail for the axial sections of the cylindrical worms as specified in DIN 3975 and for the reference circles of the associated worm wheels. Module m in mm Module m 1 inmm Other relevant standards DIN 780 Part 1 Se
4、ries of modules for gears; modules for spur gears DIN 3975 Definitions and parameters for cylindrical worm gears with 90“ shaft angle DIN 3976 Cylindrical worms; dimensions, correlation of shaft centre distances and gear ratios of worm gear drives Explanatory notes The modules listed in this standar
5、d correspond with the series 1 modules of DIN 780 Part 1 with the exception that, instead of the rounded preferred number values 1,5; 3; 6 and 12, the basic preferred number values 1,6; 3,15; 6,3 and 12.5 have been laid down in DIN 780 Part 2 now presented. This facilitates a more uniform gradation
6、of the worm gear transmissions (see DIN 3976). When comparing the values of DIN 780 Part 1 with those of DIN 780 Part 2 it shall be noted that for spur gears (cylindrical gears) complying with DIN 3960 it is the normal modules rnn which are standardized, whereas for cylindrical worms complying with
7、DIN 3975 the axial modules m, are standardized. Their relationship is given by the equation mn mn mx=-=- sinII cosy For a comparison of the modules with the diametral pitch values still in use in the English-speaking countries, see DIN 780 Part 1, Explanatory notes. DIN 780, February 1967 edition, h
8、as been split up into Part 1 (modules for spur gears) and Part 2 (modules for cylindrical worm gear transmissions). Included for the f.irst time in DIN 780 Part 2 are the modules from m = 0,l mm to m = 0.9 mm which are needed in precision mechanics. Beuth Verlag GmbH, Berlin 30, has exclusive sale rights for German Standards (DIN-Normen) 11.83 DIN 780 Part 2 Engl. Price group I Sales No.0104
