| 摘要 |
PROBLEM TO BE SOLVED: To provide a thin, low noise, high static pressure axial flow impeller in which axial length of a blade is reduced. SOLUTION: A three-dimensional shape of an impeller is converted into parameters and optimized. In such a method, an intake direction front tilting angle δZ at a section when an impeller is cut at a cylindrical surface with a radius R around a rotary shaft 3 is indicated by the following equation: δz=tan<-1> (Ls/(R-Rb)), where δZ ranges between 0 and 10 degrees, Ls denotes a spacing between a center point PR of a blade chord line and a perpendicularly crossing plane Sc with the rotary shaft, Rb denotes a radius of a boss part 2. At a projection surface of the impeller onto a plane crossing perpendicularly to the rotary shaft, the rotational direction advancing angle δθ is indicated by the following equation: δθ=δθt×(R-Rb)/(Rt-Rb), where Rt is a radius of a blade tip, δθt is an angle made by a staright linePt'-O and an X axis. At this time, δθt ranges between 50 and 70 degrees. |
