| 摘要 |
1464589 Propellers VOLVO PENTA AB 10 Dec 1974 [19 Dec 1973] 53397/74 Heading B7V A propeller is formed with a hub having a passage 3, e.g. for exhaust gases, and the rear end of the hub is formed with a groove 5, to cause water passing the propeller to flow transversely to form a shield preventing back suction of gases -towards the propeller blades. The groove can have a lip (10), Figs. 3 and 4, not shown, projecting towards the front. Passages (11) and (12), Figs. 3 and 5, not shown, can be disposed in the hub. The rear part (7), Fig. 4, of the hub can be resilient. The groove can be of helical form. The suction side of the propeller blades can have transversely extending grooves. |
