Study Of Rotor Radial Vibration Measurement Method

At present, the eddy-current sensor which is based on the principle of electromagnetic induction is used mostly in vibrant radial displacement measurement of the rotor, thereby no electromagnetic interference is allowed existing around the rotor that is measured. In addition, the rotor be measured must be a pure metal and its material is uniform. However, there are electromagnetic interference here and there nowadays, and we often use the alloy rotor in some application, thus the method have couldn't meet the current industrial production needs already, so we must seek a new one.According to these reasons, a new method of the vibrant radial displacement measurement is presented in this paper. The linear-CCD is acted as image sensor and is placed at the radial direction of the rotor in this method. Providing the lighting, rotor vibration is imaging on the CCD photosensitive unit, which will output the signal under the drive of the peripheral drive circuits. Further, the video signal must be magnified,filtered and two value processed, we can get a rectangular pulse width that represents radial vibrant displacement of the rotor finally, the counter count the value of this pulse width using pulse filling , the value are sampled by MCU and are send to computer through simple USB interface, host computer deal with those sampling data, and take Fourier,wavelet transformation with them,then we can know if there is some fault on the rotor, and the moment of the fault. Thus a measurement system will be composed of the linear-CCD sensor, the counter, the MCU, the simple USB interface and the computer.Based on the principle above, this paper designed one optical system, one hardware circuitry and one software system. By experiment, the method was founded that can measure the radial vibrant displacement of low speed vibrant rotor, overcoming the harsh shortcomings what eddy-current sensor appealed for the rotor rigorously.