A replacement bearing can run hot even when its basic number matches the removed part. Suffixes, shaft condition, housing fit, axial location and the mounting method all influence the installed result. Paper cup machine bearing replacement therefore begins with the complete bearing arrangement, rather than an order based only on bore size.
Use this guide after condition checks have established that removal is necessary. It addresses replacement preparation and acceptance; it does not supply a universal fit class or heating temperature. Identify the driven station and obtain the approved assembly drawing before dismantling.
Diagnostic decision table
| Observed evidence | Question to resolve | Hold point |
|---|---|---|
| Polished ring seat or reddish debris | Has the ring moved on its seat? | Measure the seat before fitting a new bearing |
| Only a basic bearing number recorded | Are clearance and seal suffixes missing? | Confirm the complete replacement designation |
| Heating after assembly | Is fit, preload or lubrication incorrect? | Stop and investigate before production release |
| Repeated failures at one station | Is shaft loading or alignment abnormal? | Review the surrounding drive arrangement |
Identify what must be preserved
Record the full markings on both bearings where a shaft has a pair. Photograph spacer order, retaining rings, locknuts, shields and seal direction before removal. Establish which bearing locates the shaft axially and which arrangement accommodates expansion. A machine can lose this freedom when a spacer is reversed or a retaining component is tightened against the wrong surface.
Compare the drawing with the installed assembly. A previous repair may have introduced an undocumented substitute. Send discrepant markings to the supplier before ordering; a matching outside diameter alone does not establish compatibility.
Measure the shaft and housing after removal
Isolate electrical, pneumatic and stored mechanical energy, support the shaft and remove the bearing with the documented tools. Clean the seats without grinding away evidence. Measure at several axial positions and angular directions with appropriate calibrated instruments, recording temperature and measurement locations.
Compare size, roundness and surface condition with the drawing. Score marks, burrs, fretting or a visibly loose seat require a repair decision. Retaining compound, centre punching and a tighter bearing are not substitutes for an approved seat repair. Keep the removed part labeled for inspection.
Confirm the mounting force path
SKF identifies load, clearance, temperature and shaft/housing construction among the factors controlling fit selection. For an interference fit, use tooling that applies force to the ring being fitted. Passing mounting force through the rolling elements can damage an otherwise new bearing.
Choose the mechanical or controlled heating method specified for the bearing and assembly. Seals, grease and sensors can limit the method. Never infer a heating target from another bearing size. Record the method, tool identity and any abnormal force so a later temperature rise can be investigated.
Restore location and lubrication deliberately
Refit spacers and retention components in their verified orientation. Check the specified axial clearance or preload using the assembly procedure; free hand rotation alone cannot prove it is correct. Inspect seals and nearby lubrication lines for damage introduced during removal.
Confirm lubricant type and quantity from the lubrication plan, including whether the bearing arrives sealed and prefilled. Additional grease can be inappropriate for a sealed bearing. Cleanliness matters at the point of assembly: keep protective packaging in place until the component is ready to mount.
Release the station using a trend
With guards restored, run the staged commissioning sequence approved for the machine. Compare shaft movement, sound, drive current and temperature trend at the same measurement point. Then repeat under representative cup material and load. Stop on rapidly rising temperature, binding or abnormal motion.
Document the accepted operating condition rather than one isolated temperature. If the problem returns, investigate alignment, external belt or chain load, lubrication delivery and the repaired seats. Provide HANNAI with the full bearing codes, seat measurements and restart record when requesting a compatibility review.
Related equipment and next checks
Review the HN-M100 paper cup machine and the related guide to bearing condition monitoring. The Engineering Notes archive connects these checks with wider machine planning.
Technical reference
- SKF shaft and housing fit guidance — general reference; confirm applicability to the installed equipment.
Frequently asked questions
Is the basic bearing number enough to order?
No. Include all suffixes and the assembly requirements.
Can adhesive repair every loose bearing seat?
No. Seat repair requires measured evidence and an approved method.
Should every bearing receive extra grease?
No. Follow the lubrication requirement for that exact bearing.
What confirms a successful replacement?
Correct assembly checks and stable results during a controlled loaded restart.
Review the evidence with HANNAI
Send your machine model, component identification and the observations described in this guide. Include the drawing or material reference and any before-and-after measurements so the required next check can be identified.