Gear assembly

摘要

A gear assembly comprises at least two gears, each of which is formed by injection molding and has a plurality of ribs on their bases. The two gears have a gear ratio of 1:N and a ratio of the number of ribs is 1:M (N and M are integers). Alternatively, the two gears are supported in positions where one of ribs on one gear and one of ribs on the other gear lie on the same line at a predetermined number of times while one of gears rotates once. The two gears can also be supported in positions where the ribs on the two gears have predetermined positional relationships so that the two gears rotate at a constant angular speed.