Radio-Wave Motion Transducer for Measuring the Parameters of Torsional Vibrations of a Turbine Unit Shaft

This paper devoted to radio-wave motion transducers for monitoring the parameters of torsional vibration of turbine unit shaft. The known devices and methods for monitoring the parameters of torsional vibrations of a turbine unit shaft are considered. A method for measuring the parameters of torsional vibrations of a turbine unit shaft is proposed based on the use of special cylindrical marks located on the surface of the turbine unit shaft, which make it possible to increase the information content of the autodyne signal by increasing the width of the scattering pattern of the reflected radiation. A mathematical model of the interaction of a radio-wave transducer with cylindrical marks on the surface of the controlled shaft has been developed. The distance traveled by the probing beam from the receiving-transmitting element of the autodyne transducer to an arbitrary point located on the surface of the shaft is determined. A relationship has been established between the instantaneous phase of rotation of the turbine unit shaft and the geometric dimensions of the shaft, the dimensions of the cylindrical mark, and the distance between the radio-wave transducer and the cylindrical mark. A method has been developed for measuring the parameters of torsional vibrations of a turbine unit shaft, based on an analysis of the shape of the autodyne signal obtained during the interaction of a radio-wave transducer with cylindrical marks located on the surface of the controlled shaft. The results of applying the method to measure the parameters of torsional vibrations of the turbine unit rotor shaft were checked, and the measured parameters of the shaft vibrations were compared with the parameters of the oscillatory process specified using the simulator.