Patent attributes
A case for a differential gear set includes: a rotatable carrier having a cylindrical fitting face and a radially projecting flange having an axially directed butting face; a cover having a brim section so projecting axially as to fit on an outer periphery of the flange and so dimensioned as to align an end face of the brim section with the butting face; a ring gear fitting on the fitting face and having a back face in contact with the butting face; and a weld metal uniting the carrier, the cover and the ring gear together, wherein the butting face of the carrier, the end face of the cover and the back face of the ring gear are so dimensioned as to keep a circular groove exposed outward and reaching an interface between the back face and the butting face and the weld metal fills the groove.