| 摘要 |
PROBLEM TO BE SOLVED: To prevent the leakage of air from the joint between the main body frame and interior body of a casing which surrounds air blowing vanes and is composed of the main body frame and interior body and, at the same time, to normally maintain the clearance between the interior body and air blowing vanes by forming the interior body of a foamed plastic. SOLUTION: A rib 43 is provided on the internal surface of a main body frame 25 and the inner peripheral section of an interior body 38 made of a foamed plastic is brought into contact with the outer peripheral section of the rib 43. Since the diameter of the interior body 38 is apt to be reduced due to a secular change, the contact pressure of inner peripheral section of the interior body 38 with the outer peripheral section of the rib 43 increases and the degree of contact between them increases. In addition, the rib 43 also functions to suppress the secular change (diameter reduction) of the interior body 38. |
