| 摘要 |
A propeller for e.g. a ship has a central hub (7) with a plurality of propeller blades (8). Each blade (8) is composed of an elastomer, such as rubber (10), having a flexible core (9), which may e.g. consist of a relatively thin, corrugated plate of spring steel. The core (9) and a hub bushing (11) of e.g. bronze are moulded and vulcanized to an integral unit which, without expensive after-treatment, forms a propeller having a finished smooth surface and a consistency capable of absorbing and damping impact and shock pulses from the reaction forces of the water. The corrugation of the blade is in the form of folds extending outwardly from the hub. Even with a thin plate the blade hereby obtains a sufficiently great rigidity transversely to the direction of rotation of the propeller, while the blade is allowed to twist and bend in response to the load, so that the pitch of the blade is optimally adjusted to the instantaneous state of operation. |
