IE B012EQUIPMENT RESTORATION REPORT · CEMEX DOMINICANA
MAAG WPU-242B cement mill gearbox: bearing back to normal without replacement
Gearbox vibration dropped, bearing sensors came out of alarm, replacement was not required. 2.6× — overall vibration level of the gearbox, 1.7 → 0.65 G (2018).
signatures and stamps of the parties
Key result
| EQUIPMENT | CONDITION AT THE START OF WORK | WHAT WAS MONITORED |
|---|---|---|
| MAAG WPU-242B gearbox | Mill No. 3 in operation, 1,000 rpm at the input shaft, dimensions 3900 × 3000 mm | Overall vibration level (OVL) |
| Drive pinion bearing (No. 9 in the monitoring system) | Increased clearance since June 2014, position sensors No. 32 and No. 33 in ALERT state | Vibration acceleration at two points |
| Gearbox lubrication system | 1,000 l of oil, filtration fineness 15–25 µm | Oil temperature and pressure |
Gearbox diagnostics by the permanent vibration monitoring system
| MONITORING POINT | BEFORE TREATMENT | AFTER TREATMENT |
|---|---|---|
| Overall vibration level (OVL) | 1.7 G | 0.65 G |
| Sensor 6 — vibration acceleration, bearing pos. No. 32 | ALERT | OK |
| Sensor 7 — vibration acceleration, bearing pos. No. 33 | ALERT | OK |
| Sensor 8 — vibration acceleration, planetary stage | OK | OK |
| Sensors 9 and 10 — vibration velocity, grinding table X and Y | OK | OK |
Sensors 6 and 7 had been indicating increased clearance in the drive pinion bearing since June 2014; in December 2015 both returned to normal operating mode.
Repair avoided: bearing replacement calculation as given in the report
| ITEM | VALUE |
|---|---|
| Bearing replacement time — mill downtime | 5 days |
| Cost of the bearing | $3,914 |
| Downtime costs | $2,827,723 |
| Cost of labour | $5,000 |
| Total for bearing replacement | $2,836,637 |
| Cost of the XADO gel-revitalizant applied | $13,589.04 |
| Calculated benefit | $2,823,047.96 |
The calculation is given in the report: the bearing was not replaced, the amounts are the plant's avoided costs of a five-day shutdown of the grinding mill.
Conclusion of the report
Current equivalent
- Revitalizant gel for gearboxesGearboxes · transmissions · gear drives
- Revitalizant gel for compressors and bearingsCompressors · bearings · spindles
How such units are treated:
About this result:
Limits of this report: The results refer to the MAAG WPU-242B gearbox of the cement grinding mill at the San Pedro de Macorís plant; with other units and operating modes the figures may differ. The economic calculation is given in the report itself and refers to the avoided bearing replacement on this mill.