On-site Inspection and repair on EKATO EKH-3V-84-670-VL gearbox

This client from THE NETHERLANDS came to us with this EKATO EKH-3V-84-670-VL gearbox. We inspected the gearbox and performed a repair. After a succesful testrun we shipped the gearbox back to the client.

Observations: During the visual inspection, the state of the toothings, bearings and the internal preservation of the gearbox were examined. For this inspection use was made of a videoscope, also the inspection hatch (with the thermal element) was removed.

oxidation has been observed in the form of black scale on the toothing, the layer has been worn away on the loaded edge of the toothing (outgoing toothed wheel) and the surface has a shiny appearance. Furthermore, slight scratches have been observed on the unloaded flank on the toothed head.

Internal preservation: The inside of the gearbox is seriously affected by oxidation in the form of dark spots, flakes and granules. The oxidation product was not attached to the surface, with slight contact it came loose. There are also accumulations of oxidation product found behind the oil caps, see photos 4 and 5.

Bearings: Because a ring was mounted against most bearings on the inside, they were not available for inspection. No substantial oxidation of the rolling elements or the running surface seems to have taken place.

Conclusion and recommendation The state of the gearbox is unacceptable; during the period of standstill, moisture has probably accumulated in the gearbox and oxidation has taken place. The product of this oxidation loosens and will lead to accelerated wear of the bearings, seals and toothing. Chances are that the bearings behind the rings are more affected because the moisture behind them could not easily evaporate.

Our recommendations are:
- Replacement of the bearings and seals
- Renew the internal preservation
- In the future, during storage, store the gearbox in a dry and warm environment and fill it with preservative oil.