Fault Phenomenon: Bauer BG22 rotary drilling rig a metallic impact sound occurs at the rotary head during startup or gear shifting.

Troubleshooting Process:
– Checked coupling: elastic rubber element worn down.
– Checked alignment: motor-gearbox alignment good.
– Checked splines: splines slightly worn.
– Checked torsion: high motor torsional vibration.

Root Cause: The elastic element in the drive coupling between the rotary head motor and gearbox wore out, causing direct metal-to-metal contact.

Required Parts: Rotary head drive coupling elastic element.