On-site Inspection and repair on ZPMC gearbox

This client from THE NETHERLANDS came to us with this ZPMC. We inspected the gearbox and performed a repair. After a succesful testrun we shipped the gearbox back to the client.

The state of the gearbox can be described as good, no damage images have been observed during the visual inspection that require action. No direct cause for the increase in wear particles in the oil has been found.

In the LSS DE bearing, standing markings on the outer ring are visible, while stopping marks are often found in cranes and windmills. These markings are caused by vibrations at a fixed position during standstill. In a more advanced stage this can develop into bearing damage.

In the HSS DE-bearing a slight attack of the rolling elements is visible, but this can only cause a slight increase of particles in the oil. There is also a possibility that no homogenized oil sample has been taken, as a result of which particles from the bottom of the cabinet end up in the sample. This paints a wrong picture of the composition of the oil.

We advise:
- Taking a sample by means of pumps from the crankcase of the gearbox, shortly after turning the gearbox and perform an oil analysis again.
- Perform a visual inspection and vibration measurement annually.