Direct Measurement Of Rotor Vibration Acceleration Method Study

Compare with rigid rotor system, the structure of the flexible rotor system be more complicate, the entire rotor rigid is smaller, the vibration become fiercely under revolution, which can cause the machine itself or the part destruction, reduces the life and the efficiency. The system must experience the first critical rotation speed during initiation process. The consequence to be extremely serious once appears the fault, Fault Diagnosis of the flexibility rotor plays an important part of Mechanical Fault Diagnosis. The traditional rigid rotor test method needs to make the improvement to meet signal gathering and the analysis of the flexible rotor system.The superharmonic components contained in vibration displacement of a rotor will become very weak in the region of supercritical speed. However they are very essential to detecting problems in rotating machines. Hence reinforcement of these components in the vibration signal measured on a machine operating in supercritical speed zone is helpful for fault diagnosis. It is noted that the superharmonic components in vibration acceleration will not decay over critical speed. If the vibration acceleration signals of a rotor can directly be measured, enhanced superharmonic components may be obtained. To this end, two pairs of accelorometers are mounted on a rotor and rotate together with the rotor. The signals measured by these 4 accelorometers in rotating frame are transmitted to a data acquisition system by a slipping ring. As the 4 accelorometers are mounted in two pairs, a respective addition of the signals measured by 2 sensors in a pair will directly output acceleration signals in rotating coordinates. Furthermore a respective subtraction of the signals will supply torsional vibration signals of the rotor.