Research on torsional vibration noncontact measurement of rotary machine

Based on laser Doppler effect, single section rotational speed of a rotating shaft was measured. By measuring the two sections rotational speed, the difference of the rotational speed between the two could be made. Integrating the rotational speed difference, the relative torsional angle of the two sections under the action of torsional virbration was received, so the rotating shaft torsional vibration was gotten. Non-contact torsional vibration measurement of rotary machine was achieved. The system was designed and the experiment was done on the torsional vibration experiment equipment. The result of experimentation indicate that the relative error between Laser Doppler and conventional torsional vibration measuring method that was less than 0.2%, and the measurement accuracy of Laser Doppler was high.