Inspection and repair on LOHMANN-STOLTERFOHT GJZ 1715 gearbox

This client from Belgium came to us with this LOHMANN-STOLTERFOHT GJZ 1715. We inspected the gearbox and performed a repair. After a succesful testrun we shipped the gearbox back to the client.

This report provides an overview of the inspection and repairs carried out on theoutput shaft (assembly), of the dredgepump gearbox.

The output shaft (assembly) was overhauled in the GBS International workshop, prior to sustaining damage during transport to the vessel. Upon discovering the damage, the client returned the shaft to GBS, to assess and repair the damage.

The output shaft arrived back in the GBS workshop on the transport cradle, specially made for the shaft. Pictures supplied by the client, showed the shaft had fallen out of the cradle and onto the bed of the truck.

After the transport incident the dredge pump gearbox output shaft was taken back to the GBS workshop for inspection and repairs.

Bearings and gears showed signs of damage from the incident.

All roller bearings were removed from the shaft, using non-destructive methods (induction). And send to the Schaeffler Wuppertal facility for inspection and reconditioning. 5 out of 6 bearings were polished in order to remove grooves and scratches.
The pos. 153 bearing was more severely damaged and reconditioned according to specifications of schaeffler.
After reconditioning the bearings were suited for re-installation on the shaft.
The high speed gear wheel sustained the most damage; teeth were deformed from impact on the frame/trailer.
Both high and low speed gearwheels were checked for cracks by means of non-destructive testing; no cracks were found.
Minor regrinding of the gearwheels was necessary to remove present bumps on the contact surfaces and insure proper meshing of the gears.

No further damages were found.

For transport back to the vessel, the cradle was modified by installing fixtures to keep the shaft in position in axial direction. Bearings were secured with wood.
Both shaft and frame were tightened to the trailerbed using chains.
The shaft arrived at the vessel undamaged and was installed successfully in the gearbox.