An impeller for an axial flow fan and a method of mounting a blade on a hub for such fan

摘要

An impeller (1) for an axial flow fan comprises a hub (2) supporting the blades (3). The hub (2) has bores (5) in its peripheral surface, whereby each bore (5) has a first radially inner section (10) with larger diameter than a second radially outer section (6). Each blade (3) has a substantially circular foot section (4) allowing adjustment of the blade pitch. Each blade foot section (4) is mounted in a corresponding bore (5) by means of two connecting plates (8, 9) which in the first bore section (10) are spaced apart and face each other along substantially the entire diameter of the bore (5).