| 摘要 |
An apparatus for dynamic tests of fan impellers wherein a device (1) installed along the rotation axis O of a fan impeller (5) and intended to excite mechanical vibrations of rotating impeller blades comprises a holder (2) carrying a source (3) of magnetic field which interacts with blades (4) of the fan impeller (5). The source 3 can be magnetic or electromagnetic and has radially adjustable pole pieces 7 to adjust the gap a, between the blades 4. The holder 2 may be axially adjustable. If the blades 4 are non-magnetic ferromagnetic plates may be attached thereto. For testing an axial flow fan the holder is axially adjusted to vary the axial air gap between the pole pieces and the fan blades. A rotating magnetic field may be produced by the apparatus and may be controlled to provide different strength mechanical pulses to the blades. The holder 2 may rotate during testing. <IMAGE> |
