Bearing vibration analysis and fault-frequency checks
Trend vibration at comparable speed and load, then investigate spectral features with known bearing geometry. BPFO, BPFI, BSF and FTF describe idealised kinematics; slip and operating conditions can move measured peaks. Dimensions d×D×B alone do not provide rolling-element count or pitch diameter.
On this page9 sections ⌄
Make two vibration records genuinely comparable
Fill these fields alongside the measurement, not afterwards from memory. This worksheet defines a usable record; it does not assign a universal machinery alarm level.
On smaller screens, scroll the table sideways to read all columns.
| Record field | Enter with each measurement | Before comparing |
|---|---|---|
| Asset and position | Machine identifier, bearing designation and exact measurement point. | Confirm that both readings describe the same location. |
| Operating condition | Shaft speed, load state, time and relevant temperature observations. | Flag a changed operating point rather than labelling it deterioration. |
| Acquisition | Instrument, sensor mounting and orientation, measurement quantity, units and analysis settings. | Keep settings with the raw record; do not combine unlike measurements into one trend. |
| History | Earlier comparable reading and recent assembly or lubrication changes. | Without a baseline, describe the current observation instead of claiming an increase. |
| Corroboration | Noise, lubricant condition and safely obtained inspection findings. | Distinguish evidence already observed from checks still planned. |
From an observation to a defensible conclusion
A condition change, a candidate mechanism and a verified cause are three different statements.
The fault-frequency calculator is a separate, geometry-dependent check. It cannot obtain internal geometry from an audio recording, a nominal outside diameter or an unverified model match. Keep unknown inputs unknown; do not turn a calculated frequency into a condition certificate.
On smaller screens, scroll the table sideways to read all columns.
| Statement | What supports it | What to do next |
|---|---|---|
| The record changed | Two comparable measurements with their operating and acquisition context. | Check the event history and retain both originals. |
| Bearing involvement is suspected | Several consistent observations, not a single isolated symptom. | Document alternative sources and choose a discriminating inspection. |
| A cause has been established | Inspection and operating evidence support the cause and rule out relevant alternatives. | Record the finding separately from the initial hypothesis and use the approved corrective procedure. |
What the evidence can — and cannot — tell you
| Observation or context | Interpretation to consider | Verification needed |
|---|---|---|
| A change in overall vibration | A condition has changed | Retain units, bandwidth, sensor orientation and speed with the measurement. |
| A peak close to a bearing frequency | Potential bearing-related excitation | Check harmonics, modulation and other mechanical sources before attribution. |
| Different readings after moving a sensor | Measurement setup changed | Repeat at the original point with consistent mounting. |
A practical investigation sequence
Identify and record
Record the exact model and sensor position. Keep acceleration, velocity and displacement separate; RMS and peak values are not interchangeable.
Check the context
Obtain rolling-element geometry from a trustworthy model-specific source. Leave unknown geometry blank rather than estimating it from the outside diameter.
Verify before acting
Enter speed in rpm in the existing calculator and compare its Hz output with your spectrum. Check whether the assumed stationary outer ring applies.
Keep the decision traceable
Correlate vibration with temperature, sound, lubricant condition and inspection findings. Preserve raw records to distinguish gradual deterioration from a sudden event.
Capture the information a model search cannot guess
Keep this checklist with your inspection or comparison. Checking a box only records that you have collected the item; it does not certify the bearing.
0 of 4 information groups recorded.
Technical basis & editorial scope
Original BearingScope workflow, written for catalogue research and comparison. Manufacturer material is used to check principles, not copied as a product endorsement or substituted for model-specific instructions. Reviewed 1 October 2026.
- NSK Bearing ABCs — Damage and countermeasures — Rolling bearing damage patterns; symptoms alone are not a diagnosis
- JTEKT Basic Bearing Knowledge — Test run, tables 15-5 and 15-6 — Trial operation, abnormal sound and temperature trends
- NSK — Operation inspection / running tests — Reviewed 4 October 2026. Symptom and event-led inspection principles, not a machine-specific diagnosis or operating approval.
- NSK — Damage and countermeasures — Reviewed 4 October 2026. Symptom and event-led inspection principles, not a machine-specific diagnosis or operating approval.
- NSK — Bearing inspection — Reviewed 4 October 2026. Symptom and event-led inspection principles, not a machine-specific diagnosis or operating approval.
- NSK — Regular maintenance and inspections — Reviewed 4 October 2026. Symptom and event-led inspection principles, not a machine-specific diagnosis or operating approval.
- JTEKT — Test run — Reviewed 4 October 2026. Symptom and event-led inspection principles, not a machine-specific diagnosis or operating approval.
- JTEKT — Maintenance and inspection — Reviewed 4 October 2026. Symptom and event-led inspection principles, not a machine-specific diagnosis or operating approval.
- JTEKT — Methods of analysing bearing failures — Reviewed 4 October 2026. Symptom and event-led inspection principles, not a machine-specific diagnosis or operating approval.
Source addresses and collection status are retained in the internal audit. No unpublished dimensions, torque settings, service intervals or interchange approvals are inferred.