Shaft Vibration Analyzer

Control Systems


This system analyzes the shaft vibration of various rotating machines such as generator turbines, and also calculates the balance of the shaft.

Based on a phase reference signal and the vibration waveform signal measured with a shaft vibration detection sensor, modal circles (Nyquist plots), V-S graphs (vibration vs. rotation speed graphs), and other graphs can be displayed in real time, allowing you to confirm that the rotating machine is working properly.

In addition, by using the modal circles mentioned above, you can also calculate the optimum mass and location of a balance weight to offset the unbalanced component (location of the balance hole).


Example of Online Screen Monitoring


Data Analysis

Phase Analysis

Vibration vectors are calculated based on a phase reference signal and the vibration waveform signal.
A modal circle is a plot of vibration vectors when the machine's speed of rotation increases or decreases.

Frequency Analysis

The vibration spectrum is calculated by performing FFT analysis of the vibration waveform signal.

Trajectory of The Center of The Shaft

The center position of the shaft can be calculated from the gap voltage of the vibration waveform signal.

Lissajous Curve

The movement of the center position of the shaft when the shaft rotates once can be calculated.


Online Spectra


Lissajous Curve Linking All Channels

Balance Calculation

The vibration vectors and the effect vector (the vector that indicates the effect of installing a balance weight) are measured at a maximum of 16 evenly distributed rotation speeds. Vibration values at six of those measurement points are selected and, based on them, the optimum mass and installation location for a balance weight can be calculated to minimize vibration.

System Configuration


Shaft Vibration Analyzer

  • A one-pulse signal and the shaft vibration signal measured by a sensor installed on the rotating machine are fed into the shaft signal analyzer.
  • Based on the measured data, the system performs analyses including phase and frequency analyses.
  • The analysis results are displayed on a monitor.
  • The analysis results are saved to an HDD.