US Patent 9297449 Ring gear fastening structure

Disclosed is a ring gear fastening structure in which a ring gear is fastened to the flange of a differential case configuring a differential sub-assembly. The inner circumferential surface of the ring gear is press-fitted into the outer circumferential surface of the flange, and the ring gear is swaged by means of a swage part which is disposed on at least one end of the flange in the axial direction. The inner circumferential surface of the ring gear is formed with a circumferential groove which extends in the circumferential direction of said inner circumferential surface. The circumferential groove is disposed facing the outer circumferential surface of the flange.