| 摘要 |
PURPOSE:To reduce airflow flowing into circumferential direction along the inner diameter of a runner and reduce disagreeable sounds by a method wherein a distance between the inner diameter of a bell-mouth at delivery port side and the inner diameter of the runner is increased. CONSTITUTION:In case the center Q of the bell-mouth 6 is deviated to the opposite direction of the delivery port 4b with respect to the center P of the runner 2, the distance between the inner diameter 2a of the runner 2 at the delivery port 4b side and the inner diameter 6a of the bell mouth 6 is increased, therefore, a resistance between both parts is increased, the airflow flowing into the circumferential direction along the inner diameter 2a of the runner 2 near the delivery port 4b is reduced and the airflow flowing toward the delivery port 4b is increased. Accordingly, an eddy current, generated between these two airflows, reduces the disagreeable sounds since the airflow flowing into the circumferential direction along the inner diameter 2a of the runner 2 is reduced. The eccentricity between the center P of the runner 2 and the center Q of the bell-mouth 6 is the most effective when it is about 10% of the inner diameter 2a of the runner 2. |
