Inspection and repair on RENK TACKE HSU-800D gearbox

RENK TACKE gearbox
HSU-800D
Input=___ rpm / ____ KW

GBS Gearbox Services International was approached by a client in the maritime market, their vessel, the Holland Klipper had some problems with their RENK gearbox and therefor couldn’t continue the journey to unload a large cargo of mackerel in Port Harcourt. Repair on this gearbox was required after finding considerable damage on the bearings in the gearbox. Due to the limited time given we had to do an temporary repair on the gearbox in order for it to deliver its cargo.

Due to a broken lubrication pipe, the bearings in the gearbox had run dry for almost 40 seconds. The bearing that had suffered the most was the input shaft bearing because that bearing runs at the highest rpm. Inspection revealed a lot of damage on the axial surface of the bearing. Hereby the white metal surface of the bearing had completely came off and the only contact was steel on steel. Our technician who has flown to Nigeria in order to make the vessel operational again had to remove both bearings on the input shaft. After removing the bearings, he found damage on the input shaft itself and had to make the surface of the shaft as smooth as possible with whetstone and sandpaper in order to make a clean fit for the spare bearing on the input shaft.

On the engine side bearing we found some radial damage due to little particles of white metal that had run through the oil system, here we also needed to remove the scratches by hand and make a smooth surface. The axial bearing-pads on the output shaft also had some damage by dirt in the oil system so they had to be dismounted and cleaned by hand.

Finally we lowered the cover of the gearbox and started mounting the coupling, put the pipes of the oil system back on and started with flushing of the oil system. We had to flush the system all night and cleaned the filters three times.

The next day we could start with testing the gearbox, we tested in 4 stages:
15 minutes with 0% load
30 minutes with 20% load
45 minutes with 40% load
60 minutes with 60% load

After every stage we opened the cover and checked the conditions of the gearbox. There were no deviations found. With this emergency repair the vessel was operational within 5 days, in our report we mentioned the fact that this is just a short-term solution and that we would have to do an complete overhaul of the Renk gearbox in order to prevent long-term problems.