| 摘要 |
<p>The present invention deals with a six degrees of freedom electronically controlled lifters for bridge decks. Base of the device, an hydraulic lifting system characterised by intrinsic safety, coupling the hydraulic lifting to a system of worm and internal screws, impeding unwanted system returns. To this horizontal motion according to two perpendicular directions, driven by two worm screws and supported by bearings is to be added. In this way, the device supplies three degrees of freedom of translation, whose displacement in electronically actuated and controlled. Finally three degrees of freedom are supplied by a spherical support containing anti-wear material that allows small rotations between upper and lower lifter surfaces. All linear motion are controlled by ad hoc measuring systems, being used two independent measuring systems for the hydraulic and mechanical systems, in order to coordinate their motions. Furthermore, the system is designed to transmit to the pillars also the tangential forces, due to traffic and to earthquakes, so that the deck may be considered a traditional isostatic system, hinged on a one side and simply supported on the other.</p> |
