| 摘要 |
<p>A propulsion or pumping device which includes two counter-rotating shafts (3, 4) each carrying at least one impeller (7, 8), wherein each impeller (7, 8) can deflect by a predetermined amount in directions substantially perpendicular t to the longitudinal axis of the shaft (3, 4) on which the impeller (7, 8) is mounted.</p> |
