TL;DR
Bearing noise in a gearbox is usually fatigue from exceeded service life or contamination through a failed seal. Drain and inspect the oil for bearing material. If debris is present, the Movigear needs replacement.
What you might see
- rumbling or whining noise from the gearbox housing
- noise does not change with load but changes with speed
- elevated housing temperature near a bearing location
- vibration frequency matching bearing defect frequencies
Likely causes
Bearing fatigue from exceeded service life or operating under shock loads
Bearing contamination from external particulate entering through a degraded shaft seal
Inadequate or contaminated lubrication reducing bearing film strength
Electrical fluting from stray currents in drives without bearing isolation
Required tools
- LOTO kit
- IR thermometer
- Vibration meter (optional)
- Drain container
- Magnet for debris inspection
Safety first
- Secure the driven load before locking out. A backdrive can cause the output shaft to rotate when the motor is off.
- A failing bearing can seize suddenly. Remove the unit from service if bearing noise is combined with elevated temperature.
Procedure
- 1
Lock out the prime mover. Take an IR temperature reading on the housing at each bearing location (typically both ends of the shaft). Compare readings. A differential above 10 degrees C indicates a problem bearing.[1]
- 2
Drain the gear oil and inspect for non-ferrous metallic fines (silver or bronze colored). These indicate bearing cage or rolling element material.[1]
- 3
If vibration analysis equipment is available, measure the vibration spectrum. Bearing defect frequencies appear as sub-harmonics of the shaft speed.
- 4
Inspect the shaft seals for condition. A damaged seal allows external contamination directly to the bearings (see the oil-leaking procedure on this machine).
- 5
If bearing material is confirmed in the oil or if vibration and temperature exceed limits, the SEW Movigear needs replacement. The unit is a sealed, integrated design and internal bearing replacement is not a field procedure.
- 6
When ordering a replacement, confirm the type code, ratio, and mounting interface match the existing unit.
Sources
SEW-Eurodrive Movigear Operating Instructions, SEW-Eurodrive
SEW-Eurodrive Movigear Installation and Operating Instructions, bearing condition monitoring and service criteria (general)
View source
More guides for SEW-Eurodrive Movigear
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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.
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