| 摘要 |
PURPOSE:To lower the concentration of various stresses and obtain a coupled part of a high fatigue strength by inserting a riser in the groove of a commutator and welding the riser by spacing the upper end of the groove of the commutator apart from the welded part. CONSTITUTION:A groove 4 is formed at the upper end of a commutator 2, and one end of a riser 1 is inserted in the groove 4 and both ends thereof is subjected to TIG welding. In this case, the upper end of the TIG welded part 5 and the upper end 4a of the groove are spaced apart at a distance l. The distance l is selected so that, the stress concentrated part at the groove upper end part due to the riser bending load, the stress concentrated part of the welded end part and the heat influence part at the time of welding are not mutually overlapped. By these process, overlapping of the stress concentration is removed, and the concentration of stress is lowered, the maximum stress concentrated part A and the heat influence part B being separated from each other as a whole. Thus, the coupled part of high fatigue strength can be obtained. |
