Theoretical Basis of Generation of Face Worm Gear Drive With Duplex Worm

New type of face worm gear drive with double-lead worm is proposed. The advantages of that gear in comparison to contemporary known gears are also mentioned. The shaping process of the face worm gear is carrying out by means of a single point tool. The same insert is used for cutting the duplex worm. Using a single point tool instead of hobbing cutter considerably reduces the manufacturing cost, in which the share of tool production plays the main role. The shaping process is performed on a CNC milling machine with or without additional equipment. Two main methods of shaping depended on setting up the tool machine are presented. One of them requires no special equipment but a single point tool with insert of specific tool included angle, whilst the second uses a constructed tooling. There are also described 3 methods of shaping the face toothing, which depends on the used technology. Geometry of that face worm gear drive is presented and described. The tooth depth is constant along the whole tooth line. Nominal width of tooth section as well as its location depends on the lead difference of the worm. Provided scheme can be used to calculate those parameters. The total length of the duplex worm is calculated by taking into consideration the internal and external diameters of the worm gear and the additional length which is needed to reduce the backlash. The shape and size of the single point tool is determined according to the worm and the necessary geometric model is provided. There are also given criteria, which limit the maximum length of worm and its maximum lead angle. A complete algorithm describing the designing process of that type of gear is presented in the final part of the article.