Position (displacement) encoder and thrust piston mechanism having a position encoder

摘要

A position encoder has a guide tube with guide elements, and a guide rod which is arranged such that it can be displaced longitudinally and rotated inside the guide tube and has guide grooves which are connected in a rotationally secure manner to a rotary potentiometer. The guide elements engage in the guide grooves. The encoder is arranged such that a tubular housing is provided for accommodating the guide tube, the guide rod and the rotary potentiometer, that the rotary potentiometer is mounted in the housing at one end thereof and the guide rod is mounted, opposite said potentiometer, by means of at least two spirals situated opposite one another on the circumference, that the guide rod is surrounded by the guide tube with at least two balls situated opposite one another on the circumference and engaging in the spirals, and that a drainage valve is provided on the external end of the guide tube.