2009 年 75 巻 752 号 p. 1072-1080
The heat generation due to friction between tooth flanks and hysteresis of plastic material greatly affects the load capacity of a plastic gear especially in operation without lubricants. And the heat radiation of plastic gears generally decreases with the increase of facewidth and module under the same gear rotation speed. Therefore, tooth temperature increases in case of large facewidth and/or module. Friction and hysteresis that causes heat generation are not proportional to gear rotation speed, so that tooth temperature should be determined considering facewidth, module, and gear rotation speed. However, the effect of tooth temperature is usually not considered in the load capacity evaluation of a plastic gear pair. The temperature-rise factor for the load capacity calculation has been proposed considering facewidth of a plastic gear. In the present paper, the effect of module and rotation speed on the heat generation and radiation in plastic gear pair is investigated on the basis of three-dimensional analyses using a developed computer program with measured results obtained from experiments using POM gears with various modules and under various gear rotation speeds. As a result, On basis of these results, a method of determining the temperature-rise factor was proposed, and it enables not only facewidth but also module and gear rotation speed to be considered.