High precision manufacturing method of multi-thread worm wheel using 5-axis machining center

Abstract

In recent years, the speeding up of a rotary table using a worm gear pair has been required. In order to perform the speeding up of a rotary table, the multi-thread worm wheel is adopted in some cases. When a hob tool for cutting a worm wheel is likewise formed in multiple starts, a polygonal error occurs on the machined tooth surface and it cannot be manufactured with high precision. In this paper, a high precision manufacturing method of multi-thread worm wheel is proposed using a 5-axis controlled machining center. Meanwhile, the worm was manufactured using a NC worm grinding machine by a conventional method. The worm and worm wheel manufactured in these methods were meshed each other and the tooth contact patterns and transmission errors of the worm gear pairs were investigated experimentally. Furthermore, the tooth contact patterns and transmission errors were compared to the worm gear pair with the worm wheel machined using a hobbing machine. As a result, the validity of this manufacturing method was confirmed.