| 摘要 |
A device for positioning with an integrated safety function is intended for linear positioning of a flow valve rod in its preferential embodiment. The device performs a work stroke between two end positions, by which the force application point on the valve rod is moving in the same sense too. When turning the device on, a linear actuator generates the energy potential to execute the safety function by means of its work stroke during the calibration phase. At the end of calibration or respective stressing of a spring (5), a system of elements for transformation and reduction of force lowers the force for retention of the prestressing force by means of its non-selflocking thread connection. In this way, the device is storing a constant energy potential for the execution of the safety function, in which case the device for retention of the prestressing force does not consume the electric power. In the case of electric power outage, the system of elements for transformation and reduction of the retention force gets unlocked, by which the safety function is activated and executed to shift the valve rod into a predetermined end position. |
