| 摘要 |
PURPOSE:To increase the strength and enhance productivity by rounding a plurality of steel plates, providing them with a guide groove at each outside surface, forming a cylinder through conjunction of these steel plates in such a way that said guide grooves will be continuous, and then fitting caps on both ends of the cylinder. CONSTITUTION:A plurality of steel plates 1 are rounded by a press each into an arc of circle, wherein a guide groove 2 is formed at each outside surface. Then these steel plates 1 are butted at their mating side edges 1a, 1b in such a way that said guide grooves 2 will be continuous, and the butted parts are plasma arc welded into a cylinder a. Then caps 3, 4 are fitted on both ends of the cylinder a and fixed by plasma arc welding to provide a change drum A. Thereafter the abovementioned guide grooves 2 are fine shaped by trace processing, and the welds W1 are machine - finished, to be followed by flattening of the product surfaces as well as grinding of the shafting parts 3a, 4a of the caps. |
