Principles of Rotating Machine Vibration Signals

All rotating machines produce vibrations due to dynamic forces, i.e. repeating forces, which mostly come from imbalanced, misaligned, worn, or improperly driven rotating parts. This chapter presents the principles of rotating machine vibration and acquisition techniques. It provides a presentation of vibration basics, vibration signals produced by rotating machines, and types of vibration signals. Vibration signals produced by machines can be categorised into two main groups: stationary and nonstationary. The most common sources of vibrations in machinery are related to the inertia of moving parts. The chapter describes some of the widely investigated sources of rotating machinery vibration signals. It is concerned with vibration data acquisition techniques and highlights the advantages and limitations of vibration signals. Vibration signal acquisition includes the measurement of three main quantities: displacement, velocity, and acceleration.