Patent ID: 7698964

Claim:
A gear comprising: a thin-walled section formed on at least one of two end faces of the gear, the end faces being located on opposite sides of a tooth, the thin-walled section being formed in a tooth-width direction and project outwards in the tooth-width direction, wherein, the thin-walled section includes: an overhanging section formed along one tooth flank side of two tooth flanks of the tooth and formed so as to project toward a tooth flank of an adjacent tooth which is located on the one tooth flank side, said overhanging section being sloped from a base end, which is near the one end face, to a tip end, which is far from the one end face, a tooth crest corresponding section formed along a tooth crest of the tooth and continuous to the overhanging section, a tooth flank corresponding section formed along the other tooth flank of the two tooth flanks of the tooth and being continuous to the tooth crest corresponding section, and a bottom land corresponding section formed along a bottom land of the tooth and being formed so as to continuously connect the overhanging section and a tooth flank corresponding section formed in the tooth adjacent to the one tooth flank side; and wherein a projection amount at the tip end of the overhanging section is greatest at an intermediate section which is between the tooth crest corresponding section and the bottom land corresponding section and intersects with a pitch circle of the gear, and thicknesses of the thin-walled section satisfy the following: T1<T3<T2, T5<T3, T6<T3, T6<T4, and T5<T6 in which T 1 is a thickness of the tooth crest corresponding section, T 2 is a thickness of the tooth flank corresponding section, T 3 is a thickness of the overhanging section, T 4 is a thickness of the bottom land corresponding section, T 5 is a thickness of a first connecting section that is a connecting section between the tooth flank corresponding section and the overhanging section, and T 6 is a thickness of a second connecting section that is a connecting section between the overhanging section and the bottom land corresponding section.