| 摘要 |
<p>An apparatus for oscillating and orienting a vane (2) relative to a fluid, comprising a main lever (32) pivotally connected at one end about a reference axis (4); a vane pivotally connected to the main lever about a vane axis (6) remote from the reference axis, the vane axis being substantially parallel to the reference axis; a main drive means for oscillating the main lever about the reference axis so displacing the vane from side to side; an angle change assembly (7) for pivoting the vane about the vane- axis comprising (i) an angle drive means adapted to oscillate with a phase lag of approximately 90 degrees to the main drive means; (ii) control means connected between the angle drive means and vane adapted to convert the oscillation of the angle drive means to oscillation of the vane about the vane axis; and, (iii) an offset means adapted to add an offset to the centre of angular oscillation of the vane about the vane axis.</p> |
