Patent ID: 7415907

Claim:
A resin double helical gear comprising: a first gear portion arranged on one side in face width directions from a substantially central portion in the face width directions, said first gear portion having teeth which are helical in a direction; a second gear portion arranged on the other side in the face width directions from the substantially central portion in the face width directions, said second gear portion having teeth which are helical in a direction opposite to that of said first gear portion, said first gear portion and said second gear portion being molded so as to be integrated with each other in such a shape that a pair of helical gear halves being helical in opposite directions to each other are stuck together; and a stepped portion of each of teeth between said first and second gear portions, said stepped portion being elastically or plastically deformed to collapse to allow an excess thickness due to deformation of said stepped portion to be received in a space between said resin double helical gear and a companion gear when said resin double helical gear meshes with said companion gear.