Calculation of the shape of tool cutt ing edge for production of involute worm

The article deals with theoretical analysis of the production of worm gears and also the calculation of the tool cutting edges for their production. Based on the design parameters of worm and worm wheel, it is possible to calculate the coordinates of the shape of the tool cutting edge. The exact calculation of the coordinates or parameters requires mathematical formulations and applying mathematical relationships we can transform the design of worm screw profile to the profile of tool. Worms of different types can be produced in various ways, e.g. with a lathe and the plane to set a tool is either axial or normal. In this article we consider their production on the lathe and tool setting in the normal plane. Axial profile of worm is a curve which is the intersection of worm surface and the plane passing through its axis, and normal profile is perpendicular in a selected point to worm profile. This normal profile in more accurately way characterizes the shape of the worm profile, therefore, the calculation of the shape of the tool cutting edge is designed with a tool set to the normal plane. Based on the analyses, the new computation equations were obtained, flowchart compiled and, according to a given regulation, the computer aided calculation of the coordinates can be implemented.