Coupling Exchange

Intro

Alatas was contracted to remove and replace the coupling between the hoist gearbox and rope drum, which had failed in service.

BACKGROUND

The coupling had failed in service and needed to be replaced. During the removal of the coupling, it was discovered that it had become seized onto the gearbox shaft. The gearbox was removed as a replacement shaft had to be manufactured and installed.

ALATAS’ SOLUTION

The shaft was damaged in one location due to the fitment of the coupling; therefore, it was decided that the gearbox needed to be removed along with the shaft and coupling to enable a complete assessment and repair. The shaft was beyond repair, and a new one was manufactured in the Alatas workshop. The gearbox was fully overhauled at the same time. As part of the repair, the rope drums were removed, and during the reinstallation, it was found that the mounting plates were not correctly centered. This had caused misalignment from the new and had accelerated the coupling wear; this was corrected prior to reinstallation and alignment proved for drums, coupling, gearbox, and drive motor.

JOB SCOPE

• Remove ropes
• Remove brakes, main, and emergency
• Remove hoist drums
• Remove the gearbox, shaft, and coupling from the crane
• Manufacture new shaft
• Overhaul gearbox
• Reinstall the gearbox in the crane and fit the new coupling to the output shaft
• Fit new pedestal end bearings.
• Reinstall drums to shaft and coupling
• Reinstall brakes
• Align drum and coupling
• Align motor and gearbox
• Function test
• Complete full load test.

Coupling Exchange Gallery