| 摘要 |
<p>Centrifugal pumps compose a unit with impeller wheels (17, 18) and flow body (19). The second centrifugal pump is arranged underneath the first centrifugal pump and both centrifugal pumps are in communication with the reservoir (14) through a duct (21, 22). The cylinder (3) chamber (6) is closed above the piston (4) in relation to the reservoir (14) and is linked to the second centrifugal pump by means of a pressure line (24). When the electric motor (2) turns in a predetermined direction of rotation, the first centrifugal pump is driven by a shaft (15) and when it turns in the opposite direction of rotation the second centrifugal pump is driven by the shaft (15), whereas, in each case, the other centrifugal pump runs freely, so that the piston (4) may be moved both upwards and downwards.</p> |
