Prevention of undercutting of the leg of the tooth of cylindrical helical gears during roughing and finishing gear processing

Abstract

Abstract The article discusses design factors leading to inconsistencies in the diametrical dimensions of the boundary point of the transition curve of the helical wheel. The conditions for the implementation of the graphic run-outs of the gear rack of a worm gear-cutting cutter, ensuring the formation of the active length of the involute wheel profile throughout its length, are formulated. The effect of a change in the design parameters of a helper milling tee on the duration of the interaction of the cutting edges and the diametric dimensions of the boundary points of the transition curve of the helical wheel is shown. Reducing the height of the prominence of the worm cutter leads to an increase in the required length of interaction in the steps of the cutter in the process of forming the active profile of the gear tooth. If the graphic run-in does not take into account the actual length of the interaction between the cutter and the workpiece, then the risk of the undercut of the tooth stem increases with decreasing height of the prominence. A diagram of the possible formation of undercutting of the tooth shaft and recommendations preventing its occurrence as a result of the implementation of graphic two-dimensional helical gears are given.