微小ねじ歯車の負荷特性に関する基礎研究

（りん青銅および合金工具鋼の組み合わせの場合）

抄録

In order to confirm the effect of material on the load-carrying-capacity, we compare the failure modes and load-carrying-capacities of phosphor-bronze micro-crossed-helical-gear, alloy-tool-steel micro-crossed-helical-gear and micro-crossed-helical-gear consisting of phosphor-bronze and alloy-tool-steel. We carried out acceleration endurance test on a crossed-helical-gear with a 0.2 mm module under the lubricant dropping condition only at the start of the experiment. As a result, in case of phosphor-bronze micro-crossed-helical-gear, extremely minute wear powder was spread thinly over the entire tooth surface, which was quite different from the tendency of wear powder in the alloy-tool-steel micro-crossed-helical-gear and micro-crossed-helical-gear consisting of phosphor-bronze and alloy-tool-steel. In case of alloy-tool-steel micro-crossed-helical-gear, At the stage where wear has not progressed and there are not many scratches on the tooth surface, the tooth surface does not retain the lubricant well and the lubricant may be discharged outside the tooth surface. The phosphor-bronze micro-crossed-helical-gear had failed tooth tips due to progressive wear, the alloy-tool-steel-micro-crossed-helical-gears had failed by plastic flow due to extremely high maximum hertzian pressure without progressive wear. On the other hand, the micro-crossed-helical-gear consisting of phosphor-bronze and alloy-tool-steel had failed due to localized high contact pressure caused by tooth tip interference. Therefore, the failure mode was different on the material.