Machining Method for Accurate Manufacturing of the Crown Reducer

- Design of 5-axis machining center tool path for rapid machining Gear Surface -

Abstract

Low backlash mechanisms are necessary to make robot motions accurate, so the authors have been proposing a new concept of a low backlash reducer using precessing crown gears. We call it ”crown reducer.” The features of the reducer are low backlash, high reduction ratio and ease of downsizing. Since the gears of crown reducer are machined by 3-axis machining center with ball end mill so far, it takes more than 10 hours to guarantee the desired accuracy. In this paper, a new machining method to improve the accuracy of the gear surface and shorten the machining time is proposed. The basic idea of the method is to generate the gear surface using 5-axis machining center and square end mill. The proposed method reduces the machining time to 50 minutes. The principle of the method is presented and the machining error of a manufactured sample is also evaluated.