Patent ID: 11898930
Assignee: SAUDI ARABIAN OIL COMPANY
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 10:
11. A system comprising:
a rotatable shaft;
a casing;
one or more journal bearings supporting the rotatable shaft within the casing;
two displacement sensors, comprising an X-axis displacement sensor and a Y-axis displacement sensor, attached to the casing and positioned orthogonally to each other on a plane transverse to a rotation axis of the rotatable shaft;
a processor and memory communicatively connected to the two displacement sensors and configured to perform steps of:
receiving shaft displacement data from a pair of sensors, wherein the shaft-displacement data comprises shaft center X-axis displacement and shaft center Y-axis displacement, wherein the X-axis displacement and Y-axis displacement are orthogonal to each other;
converting the shaft displacement data to shaft velocity data by calculating a difference in shaft displacement over time;
filtering the shaft velocity data;
sorting the shaft velocity data;
grouping the shaft velocity data into three or more velocity groups;
assigning a different color to each velocity group; and
display an image of a velocity orbit plot, where the X-axis displacement and Y-axis displacement define coordinate pairs of a trace of shaft center displacement, and the velocity group between each coordinate pair defines a display color of the trace.