RUNNER AND ITS MANUFACTURE OF HYDRAULIC MACHINE

摘要

PURPOSE:To reduce the concentration of stress in an angular corner part, by welding the angular corner part between the internal surface of a cover plate and a rib plate to be connected by fillet welding and forming a radius of curvature of said part in a size not less than 9% of the thickness of the cover plate. CONSTITUTION:Fillet welding in radius R is applied for edge preparation of the angular corner part between the internal surface of a cover plate 4 and a rib plate 3. This radius R of curvature is finished to a value not less than 9% of the thickness (t) of the cover plate 4 so that a coefficient of stress concentration becomes 2 or less. The angular corner part is finished to a smooth curved surface by grinding work or the like after the fillet welding. In consequence, the coefficient of stress concentration is reduced in a welded combined part between the cover plate and the rib plate.