ORBIGate DemoData

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How to demonstrate ORBIGate 6 :


This document shows a way to demonstrate the main features of ORBIGate 6.x through a scenario. The used data come from measurements on a rotor kit equipped with fluid bearings.

The data contain 2 major issues:

  • Oil Instability causing subharmonic phenomenon
  • Critical speed causing large orbit

To display result, use this icon:

HowToDemo ORBIGate 04.png

Rotor Kit sensor picture

Rotor Kit

Rotor kit 01.png


Rotor kit 02.png


Rotor kit 03.png


Oil instability diagnostic

  • Add/Remove result window to display :
  • Speed profile
  • Bode Plot vs RPM of 1X [RMS] overlaid by profile OVL [RMS] vs RPM
HowToDemo ORBIGate 05.png

For a good health machine, 1X should be overlaid with Overall because there is only imbalance.

However there is a speed range while overall level is higher than 1X level.

HowToDemo ORBIGate 06.png
  • To investigate what orders (in addition to 1X) are carrying energy in this speed range, let's display the synch spectrum:
HowToDemo ORBIGate 07.png
  • Place navigation cursor in the speed range of interest and look at the synch order spectrum:
HowToDemo ORBIGate 08.png
  • Subharmonic issue occurs in this speed range
  • Place windows cursor in the order spectrum to know which is subharmonic order
HowToDemo ORBIGate 09.png
  • 0.375 order means the issue cycle is completed roughly each 3 revolutions, so it could be helpful to display orbits (3 displayed revolutions)

  • First, display raw orbit
HowToDemo ORBIGate 10.png
  • Then, change analysis settings to display 3 orbits
HowToDemo ORBIGate 11.png
  • To generate report for this first issue, let's hide the second issue (critical speed). So let's focus on data related to oil instability. Select the data range of interest (with the mouse on the blue bar)
HowToDemo ORBIGate 12.png
  • Then the bode plot looks like this view:
HowToDemo ORBIGate 13.png
  • Place the cursor to display relevant result and generate a report:
HowToDemo ORBIGate 14.png

Critical speed

Let's focus now at the critical speed to know the frequency of the first bending shaft mode and the orbit size at this frequency

  • Change the data around the critical speed
HowToDemo ORBIGate 15.png
  • Add Smax (orbit size) to the window2 so that the SMAX is display with 1X and Overall
HowToDemo ORBIGate 16.png
  • Place the cursor at the critical speed and generate a new report

Shaft center line

How to display the shaft center line and use the GAP reference:

  • Display the shaftcenter line:
HowToDemo ORBIGate 17.png
  • The shaft centerline is not perfectly starting from the clearance circle, so we need to reset the gap reference at the lowest speed (when the shaft is assumed to lay at the bearing bottom).
  • Select the lowest speed with the navigation cursor and press on GAP reference:
HowToDemo ORBIGate 18.png

The shaft center line is now starting at the bottom of the clearance circle

All this demo have been done in the navigation mode, no need to post-analyze signal, all results are saved during the measurement !