IMPELLER FOR TURBO PUMP FOR WATER JET PROPULSION MACHINERY, AND TURBO PUMP INCLUDING SAME IMPELLER

摘要

An impeller for a turbo pump in a water jet propulsion machinery used as propulsion means for ships having a volute casing or a diffuser type casing. The configuration of meridian section of an impeller shroud at the side of a boss is made as a concave arc-like surface of revolution, said boss shroud at the side of the blade inlet being formed in a cylindrical form substantially parallel to a rotary shaft, and each of the blades of the impeller is so shaped that the edge of the blade inlet projects greatly toward the impeller eye with said edge being smoothly connected to the surface of said boss shroud at the blade inlet boss shroud side and the edge of the blade inlet at the side of the casing extends substantially perpendicalarly to the axis of rotation. The edges of the blade inlet at either of the boss and casing sides are connected by a smooth arc-like curve projecting convexly upstream to thereby form a continuous edge of the blade inlet, and the inlet angle of said edge of the blade inlet are uniform through the entire length and set to an angle nearer to 0 as small as possible, and the configuration of the blade at said blade inlet is connected by a smoothly curved surface to the configuration at the end of the blade outlet shaped as centrifugal or mixed flow type extending parallel or inclined to the rotary shaft.