Why should bearing vibration be compared at similar speed and load?

LILY Bearing | 2026-10-28

Best answer

Establish what is comparable before interpreting the trend

Bearing condition monitoring uses changes in operating evidence, but a value is meaningful only with its measurement context.

Speed, load, sensor location and the recorded quantity should accompany a vibration result. Comparing two unlabelled overall values cannot establish that the bearing deteriorated. JTEKT's maintenance and running-test guidance supports keeping condition observations with operating information rather than treating one number as a complete diagnosis. Identify the baseline and any known changes in the machine or setup. A consistent trend can guide further examination, while an inconsistent measurement history needs to be resolved before it supports a strong conclusion about the bearing.

Use a speed example to expose the comparison problem

A shaft at 1,500 rpm rotates at 25 revolutions per second; at 3,000 rpm it rotates at 50.

Those simple conversions show why speed-related features in a record cannot be compared as though the machine were in one unchanged state. They are not measured spectra or evidence that a particular peak is a bearing defect. Keep the actual speed, load, sensor position and analysis setup with each observation. If a repair changed the measuring point or instrument settings, identify the discontinuity in the trend. The baseline becomes useful because another reviewer can tell what remained comparable and what changed, rather than relying on a graph with missing operating context.