Abstract
The spur gears have teeth parallel to the axis. In contrast, helical gears have teeth leaned to the axis. A combination of helical gears is called the crossed helical gear. A lot of knowledge of crossed helical gear has been obtained. But the most knowledge is about the combination of the metal gear. In recent year, plastic gears are widely used in AV equipment, OA equipment and electronic equipment. But, research reports for plastic crossed helical gear is not enough. Then, in this paper, we conduct experiment in the life of the plastic crossed helical gear and the characteristic is clarified.
