WELDING METHOD AND WELDING STRUCTURE OF RING GEAR

摘要

PROBLEM TO BE SOLVED: To reduce distortion caused by welding of a ring gear to a differential case, and to reduce a welding cost.SOLUTION: In a welding structure of a ring gear, a flange 5 on the outer periphery of a differential case contains a junction part to which the inner periphery of a ring gear 6 is jointed. The junction part contains a step including a high step part and a low step part which are different in height and adjoin each other in the axial direction of the differential case. The ring gear 6 contains, on its inner periphery, a step consisting of a low step part that matches with the high step part of the junction part and a high step part matching with the low step part of the junction part which adjoin each other in the axial direction of the ring gear 6. The welding structure further includes: a first welding bead 11 provided between the high step part on the inner periphery of the ring gear 6 inserted into the junction part of the flange 5 and the low step part of the junction part; and a second welding bead 12 provided between the low step part on the inner periphery of the ring gear 6 inserted into the junction part of the flange 5 and the high step part of the junction part.