METHOD SETTING ANGLE OF MAIN PROFILE OF INITIAL RACK CONTOUR AND ITS DISPLACEMENT COEFFICIENT IN PROCESS OF CUTTING OF STRAIGHT-TOOTH GEAR-WHEELS WITH SMALL NUMBER OF TEETH OF OUTER INVOLUTE GEARING WITH TRANSMISSION RATIO EQUAL TO ONE

摘要

FIELD: mechanical engineering, manufacture of oil and fuel gear-type pumps having outer involute gearings with small number of teeth and transmission ratio equal to one. SUBSTANCE: interconnection between displacement coefficients of initial rack contour per each gear-wheel and angle of main profile of initial rack contour with change of this angle from 15 to 30 deg is established to determine zone of cutting of root of tooth of gear-wheel, coefficients of end face overlapping and thickness of tooth at tooth point. Interconnection between displacement coefficients of initial rack contour per each gear-wheel with change of displacement coefficient from 0 up to 1.0 and angle of main profile of initial rack contour with change of this angle from 15 to 30 deg is found to determine zone of sharpening of tooth point of gear-wheel, coefficients of end face overlapping and thickness of tooth at tooth point. Then required values of displacement coefficients of initial rack contour per each gear-wheel and angle of main profile of initial rack contour are determined by selected qualitative indices of gear-wheel and gearing. EFFECT: prolonged operational life and improved operation of outer involute gearing with transmission ratio equal to one by increased smoothness of its working. 2 cl, 1 dwg