Patent ID: 8070370

Claim:
A gear mechanism comprising: a pair of gears including first and second gears overlapped with each other in an axial direction, wherein: the first and second gears include first and second tooth portions, respectively; the first tooth portion slightly projects outwardly from the second tooth portion; and the first gear is formed with a deformation facilitating portion for facilitating deformation of the first gear in a radial direction, further comprising a mating gear meshing the pair of gears, wherein: one of tooth surfaces of the first tooth portion projects outwardly from one of tooth surfaces of the second tooth portion; the other of the tooth surfaces of the first tooth portion substantially overlaps the other of the tooth surfaces of the second tooth portion; one of tooth surfaces of a tooth portion of the mating gear contacts only the first tooth portion; and the other of the tooth surfaces of the tooth portion of the mating gear contacts the second tooth portion, when the other of the tooth surfaces of the tooth portion of the mating gear does not contact the second tooth portion, the other of the tooth surfaces of the first tooth portion protrudes from the other of the tooth surfaces of the second tooth portion; when the other of the tooth surfaces of the tooth portion of the mating gear contacts the second tooth portion, the first tooth portion is deformed such that the other of the tooth surfaces of the tooth portion of the mating gear contacts the first and second tooth portions.