Vibration Analysis of Precision Gear using Con-Tactless Sensors

Torsional vibration, in rotating machines, can be defined as the oscillatory motion of a rotor as it rotates. Torsional vibration can also be viewed as the cyclic variation of shaft speed. Torsional vibration, in rotating machines, can cause failures, such as: gear-tooth breakage, blade failure due to blade fatigue in steam turbines, break-off of shafts, and overloading of components fitted onto the shaft. Common sources of torsional vibration include electromagnetic torques from line frequency in electric motors and generators as well as long drive trains with massive inertial components. Even in good condition, machines generate vibrations. Many such vibrations are directly linked to periodic events in the machine’s operation, such as rotating shafts, meshing gear teeth, rotating electric fields, and so on. The frequency with which such events repeat often gives a direct indication of the source and thus many powerful diagnostic techniques are based on frequency analysis. The measurement of torsional vibration is important in analysis and diagnostics of rotating equipment.