On-site Inspection and repair on gearbox of Rhenania

A client from Netherlands came to us with this Rhenania gear unit. We reviewed the unit and did a total overhaul. After the overhaul was done, we did a test run and prepared the gearbox to be shipped back to this client.

Conclusions and recommendations

The condition of the gearbox can be considered acceptable.

Micropitting was observed on the loaded flank of the input pinion.

Various factors influence the development of micropitting, of which surface roughness and lubrication are the most important. In many cases, the damage is expressed in the form of a matte gray appearance, as a result of surface fatigue, whereby the development can be stabilized on the one hand, and progressive on the other. Progressive development can result in consequential damage such as coarser pitting and / or flaking. In extreme cases, this damage can even lead to tooth fracture.

No damage was observed on the bearings.

The outgoing dental arc coupling leaks grease through the seal (pump side).

The oil system makes a cutting noise when the switching pressure rises from 12 to 20 bar during the start. The pressure also rises fairly quickly in this range. It is possible that the accumulator no longer functions properly. The cutting noise can also be caused by a pressure control valve in the pressure control block.

It is recommended:

- Replace the oil system accumulator
- If the cutting noise remains, the entire pressure control block must be inspected / overhauled
- Install a new seal on the outgoing coupling pump side
- Perform a visual inspection and oil analysis annually.