Precision piston position monitoring system for hydraulic cylinder - uses measuring cylinder of equivalent vol. to monitor fluid leakage

摘要

The position monitoring system, used in a high temp. environment, obtains the piston position from the measured fluid leakage losses. A measuring cylinder with an identical vol.. to the working cylinder is used, lying outside the high temp. environment. One working space of both cylinders is coupled to a pumportank and each other working space coupled in flow relationship with one another. The piston rod of the measuring cylinder is coupled to a precision position display via an adjustable shutter which moves along a reference path of a coupling block to provide periodic signals for the display.