Mechanical rotation monitor for steam or gas turbine

摘要

The rotation monitor uses a bolt (3) fitted in a radial bore of the turbine rotor shaft, enclosed by a coil spring (8), acting on a piston/cylinder device at the other side. The centre of gravity of the bolt and the spring force of the coil spring are selected to ensure that the bolt remains within the radial bore at about 10% above the operating revs of the turbine, with movement from the bore at above this to operate a release latch for rapid shut-down of the turbine. The pressure medium of the piston/cylinder device is controlled for a defined spacing from a stop (5') provided by the shaft during normal operation and an increased spacing during function testing of the rotation monitor.