Emergency closing function-integrated actuating drive for valve, has buffer spring prestressing output shaft in closing direction, where spring is prestressed in opening direction during rotation of output shaft

摘要

The drive (10) has an output shaft (30) rotatable in an opening direction and a closing direction. A spindle-nut arrangement (55) has a spindle nut (50) that rotatably cooperates with the output shaft for translatory displacement of a spindle bar (56) in the opening direction and the closing direction. A compression spring (72) prestresses the bar in the closing direction. A buffer spring (36) prestresses the output shaft in the closing direction. The buffer spring is prestressed in the opening direction during rotation of the output shaft.