Piston/cylinder unit having a travel measuring device for measuring the relative travel of piston and cylinder

摘要

In a piston/cylinder unit having a travel measuring device for measuring the relative travel of piston (2) and cylinder (1), an internally threaded bush (8) is mounted in a rotationally fixed fashion in an axial through bore (7) of the piston. The internal threaded bush is penetrated by a transmission rod (9) which is provided with a corresponding external thread and is mounted in a rotatable and sealed fashion in a through bore (6), coaxial with the piston bore (7), in an end wall (3) of the cylinder (1). A displacement of the piston (2) is transformed via the bush (8) into a rotary movement of the transmission rod (9) which transmits its rotary movement onto the shaft (12), coupled to the transmission rod (9), of a rotary potentiometer (13) mounted outside the cylinder (1). The two through bores (6,7) are situated outside the piston rod (5), so that the travel measuring device can be installed in a simple way in the piston/cylinder unit without impairing the strength of the piston rod. Furthermore, the externally situated rotary potentiometer is not influenced by the pressure fluid in the cylinder. IMAGE