Hydraulic valve control mechanism - has electric motor driving screw mechanism coupled to valve control rod

摘要

The mechanism is for use with a hydraulic valve affecting the tipping moment of a crane, and which is opened against spring action by sliding a control rod (3). A screw mechanism (4) is coupled to the latter, driven by an electric motor (5) with control switch-gear (6). The nut (4a) of the screw mechanism can be mounted on the rod, and the spindle (4b) on the motor shaft. The motor can drive the spindle via a reduction gear (7), and its switchgear can comprise a desired-value potentiometer (6a), an actual-value one, and a comparator (6b). The rod can be coupled by an electromagnetic clutch to the screw mechanism, the clutch being connected to the motor control switchgear.