| 摘要 |
PROBLEM TO BE SOLVED: To achieve both suppression of air blown out of a centrifugal fan flowing back to a suction port side, and suppression of increase in shaft power of the centrifugal fan.SOLUTION: On a suction side surface 31a on which a suction port 30a is formed in a case 30 for accommodating a centrifugal fan 20, two case side protrusion parts 31b formed in an annular shape when viewed from an axial direction and protruding toward the centrifugal fan 20 side are provided, and on an upper surface side plate 22 of the centrifugal fan 20 arranged so as to face the suction side surface 31a, a fan side protrusion part 22a formed in an annular shape when viewed from the axial direction and protruding toward the suction side surface 31a side is provided. Then, grease G is filled between a radial direction of the two case side protrusion parts 31b, and a tip part of the fan side protrusion part 22a formed in a shape which is gradually tapered toward a protrusion direction is brought into contact with the grease G. |
