| 摘要 |
<p>Propeller, comprising a hub (1) and at least two cocentral vanes (2) radially projecting from the hub. The aim is to solve the problem created by high noise level occuring in propellers of prior art, mainly in blowers. It is a further aim to provide a propeller of higher efficiency than propellers known in the art, mainly for blower use but also for use in liquids. In the propeller of the invention, on the front side of each vane (2) of the propeller has been disposed a centric front louver element (7) substantially parallelling the vane and alar in shape and constituting a slot (8) between the front louver element and the vane. On the backside of each vane (2) it is possible, if desired, to place one or several centric sound suppressor fins (9, 11) substantially parallelling the vane and alar in shape and constituting slots (10, 12) between the vane and the sound suppressor fin, respectively fins. The front louver element (7), the vane (3) and the sound suppressor fins (9, 11), if any, constitute preferably a vane configuration that is concave as viewed from the pressure side of the vane.</p> |
