| 摘要 |
The fan has an impeller which consists of a hub (3) and a plurality of fan blades (1) whose outline forms an irregular quadrilateral, whose one edge is in each case connected to the hub and whose edge facing away from the hub is in each case connected over its entire length to an air-guidance element (5) which surrounds all the fan blades and is in the form of a casing. In this case, it is intended to improve the efficiency by reducing the gap losses and hence to achieve a reduction in noise in the process. This is achieved in that the edges (4), which face away from the hub (3), of the fan blades (1) are straight or curved in an angle range from 30 DEG to 60 DEG with respect to the fan axis, and in that the air-guidance element (5) starts with its radially inner end in the immediate vicinity of the air inlet opening (air inlet grid) (9) and its radially outer end extends to the fan shroud except for a separation (s) which is as small as possible. <IMAGE> |
