TL;DR
Visible tooth wear means the unit is past its designed surface fatigue life or has been running under poor lubrication or overload. Assess wear depth, identify the root cause, and plan replacement. Adding oil will not reverse surface damage.
What you might see
- polished or shiny wear facets on gear tooth flanks
- pitting visible on gear tooth contact surface
- metal debris in gear oil during oil drain
- audible change in noise under load
Likely causes
Sustained overloading beyond the Movigear rated torque reducing expected gear life
Inadequate lubrication from missed oil changes or insufficient oil quantity
Wrong oil viscosity reducing the elastohydrodynamic film thickness in the gear mesh
Gear material fatigue from accumulated operating hours, normal end-of-life wear
Required tools
- LOTO kit
- Borescope
- Drain container
- Magnet for metal debris assessment
- Camera for documentation
Safety first
- A Movigear with advanced gear tooth spalling can fail suddenly. Do not continue running a unit with confirmed heavy spalling.
Procedure
- 1
Lock out the prime mover. Drain the oil and inspect carefully for metal debris. Quantify the debris: a few fine particles after a long service interval is normal; a notable deposit of flakes or paste is not.[1]
- 2
If you have borescope access, inspect the gear tooth flanks for the depth and extent of pitting. Surface pitting less than 10% of the tooth face area may be monitorable. Spalling affecting more than 20% is a replacement trigger.[1]
- 3
Check the last oil change date against the SEW maintenance schedule. Overdue oil changes degrade the additive package and remove boundary lubrication.
- 4
Review the application load data. Calculate the actual peak torque and compare to the Movigear rated torque (from the type code on the nameplate).
- 5
If the unit is near end of life (check operating hours against the SEW expected gear life), plan a scheduled replacement before catastrophic failure.
- 6
Document the wear condition with photos for the replacement order and for the failure analysis. Include the type code, serial number, and installation date.
- 7
When ordering a replacement, verify the type code matches the application including output speed, torque, and mounting interface.
Sources
SEW-Eurodrive Movigear Operating Instructions, SEW-Eurodrive
SEW-Eurodrive Movigear Installation and Operating Instructions, gear condition assessment and service life (general)
View source
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