SUCTION BELL MOUTH, VERTICAL SHAFT PUMP AND PROCESS OF MANUFACTURE OF SUCTION BELL MOUTH

摘要

PROBLEM TO BE SOLVED: To reduce loss caused by ununiformity of flow generated by peeling of flow of fluid to improve pump efficiency and at the same time to enable an increasing in processing cost to be restricted at a suction bell mouth, a vertical shaft pump and a process of manufacture of the suction bell mouth.SOLUTION: There are provided a first ring part 41 of which inner diameter is invariable along an axis O direction, a second ring part 42 of which inner diameter is increased from one end part to the other end part in the axis O direction to form a curved shape and at the same time of which one end part is connected to an end part of the first ring part 41, a third ring part 43 of which inner diameter is increased from one end part to the other end part in the axis O direction to form a linear line inclined shape and having one end part connected to the other end part of the second ring part 42, and a fourth ring part 44 forming a disk-like shape and having its inner peripheral part connected to the other end part of the third ring part 43. The first ring part 41, the third ring part 43 and the fourth ring part 44 are formed by connecting a long sheet metal into a ring-like shape through welding and the second ring part 42 is formed into a curved shape by a cylindrical member through spinning press processing.SELECTED DRAWING: Figure 3