Rock Drill Feed Systems: Types, Maintenance, and Optimization

The feed system controls the advance of the rock drill along the feed beam, applying the correct force to maintain bit-rock contact during drilling. Proper feed system maintenance and adjustment is essential for optimal drilling performance.

Hydraulic Feed Systems

Most modern drill rigs use hydraulic feed systems. A hydraulic cylinder or chain drive advances the drill along the feed beam. Feed force is controlled by a pressure-reducing valve and can be adjusted for different rock conditions.

Pneumatic Feed Systems

Older and smaller drill rigs may use pneumatic feed systems. These are simpler but offer less precise feed force control compared to hydraulic systems.

Optimal Feed Force

The correct feed force depends on rock hardness and drill size. Too much feed force causes bit and drill wear without improving penetration rate. Too little feed force reduces penetration rate and causes bit bounce.

Feed Beam Maintenance

Keep the feed beam clean and lubricated. Inspect the feed chain or rope for wear and correct tension. Check the feed cylinder seals for leaks. A well-maintained feed system ensures consistent drilling performance.

Feed System Troubleshooting

Common feed system problems include: insufficient feed force (low pressure), erratic feed (contaminated oil or worn valve), and feed beam binding (misalignment or lack of lubrication).