Bearing checks for food-production equipment
Routine and shutdown checks for bearing lubrication, seals, temperature, vibration and abnormal condition.
Bearing checks should combine visual inspection, lubricant and seal checks, temperature, sound or vibration trends and safe examination during planned shutdowns.
A bearing can run hot, noisy or rough for reasons including insufficient or excessive lubricant, contamination, incorrect lubricant, misalignment, load, fit, seal friction or developing damage. A structured check avoids treating every symptom by adding grease.
A change in one measurement does not prove a lubrication fault. Compare trends, operating conditions and related evidence, then use the equipment manufacturer's limits and a competent diagnosis before changing the lubricant, interval or machine.
What should be checked while the machine is operating?
Only make observations allowed by the site's safe operating procedure. Guards must remain in place and no person should approach rotating or hazardous parts.
- Operating temperature compared with the established trend
- Vibration or enveloped-acceleration trend at the defined point
- Abnormal grinding, squealing, rumbling or intermittent sound
- Grease purge, oil leakage or lubricant reaching exposed areas
- Oil level, flow, pressure and sight-glass condition where fitted
- Seal condition and evidence of water or product ingress
- Automatic-lubricator status, line damage and delivery alarms
- Changes in load, speed, alignment or process condition
How should bearing temperature be assessed?
Use a repeatable point and method. Compare the reading with the same bearing's history and, where useful, similar bearings operating under similar conditions.
A rise can indicate increased friction, but ambient temperature, load, speed, cooling, recent relubrication and sensor placement can also change the value. Investigate the pattern and related evidence.
What can sound and vibration indicate?
A healthy bearing often produces a stable sound and vibration signature. Increasing overall vibration or bearing-specific frequencies can provide warning of damage, lubrication distress or contamination.
Listening by ear is a useful observation but has limited sensitivity and exposes results to judgement. Use suitable instruments and competent analysis for important assets.
What should be checked during shutdown?
Follow isolation, hygiene and contamination-control procedures before opening a housing or removing a guard.
- Leakage, purged grease and condition around the housing
- Seal wear, damage, orientation and contact surfaces
- Grease colour, consistency, water, debris and hardened deposits
- Oil level, sediment and magnetic-plug debris
- Smooth rotation and abnormal resistance where the OEM permits a manual check
- Housing fit, fasteners, alignment and signs of fretting
- Automatic lines, metering devices and relief paths
- Bearing surfaces only when planned disassembly is justified
What should happen after relubrication?
Confirm that the correct product and quantity were delivered to the correct point. Observe permitted purge and check for unexpected pressure, leakage, noise or temperature change.
Read How to lubricate bearings in food-production equipment for selection and application guidance.
What records should be kept?
- Asset and bearing position
- Check point and measurement method
- Speed, load and operating state
- Temperature, vibration and sound observations
- Lubricant type, quantity and application time
- Seal, housing and automatic-system condition
- Abnormal finding and immediate control
- Diagnosis, repair and post-work reading
Records should identify the asset and lubrication point clearly enough for another competent person to repeat the check. Preserve abnormal findings, actions and follow-up results as well as routine readings.
What are the common mistakes?
- Adding grease whenever temperature or noise rises
- Comparing temperatures taken at different points
- Ignoring changes in load, speed or ambient conditions
- Relying only on touch or unaided hearing
- Opening housings without cleanliness and food-safety controls
- Failing to inspect seals and the lubrication delivery system
- Returning the machine to service without a post-work check
Frequently asked questions
Does a hot bearing always need more grease?
No. Both insufficient and excessive grease can increase temperature. Other causes include load, alignment, fit, seal friction and damage. Diagnose the cause before relubricating.
What does dark grease mean?
Darkening can result from wear debris, contamination, oxidation or mixing, but colour alone is not a diagnosis. Compare with unused product and assess texture, water, debris and operating conditions.
Can bearing noise identify the exact fault?
It can indicate abnormal condition, but several faults create similar sounds. Vibration analysis, inspection and operating information may be needed to distinguish them.
Should every bearing have the same check frequency?
No. Base the frequency on criticality, failure-development time, operating environment, access and the monitoring technique's ability to provide useful warning.
Summary
Effective bearing checks use repeatable observations and measurements to distinguish lubrication, contamination and mechanical problems. Temperature, vibration, sound, seals and lubricant condition should be reviewed together.
Monitoring creates value when a reliable observation leads to a proportionate action and the result of that action is checked.
Need help monitoring lubrication performance?
Explore Activate's monitoring and performance verification and lubrication services, or contact the Activate team to discuss an application.
