Rotary drilling rigs are essential in construction projects, but like any heavy machinery, they can experience failures. Below are the five most common failures, along with their causes and troubleshooting methods to ensure smooth operations.
The powerhead lacks sufficient torque during drilling.
Both forward and reverse rotation speeds are inadequate.
Unusual noises from the powerhead motor and gearbox during operation.
The lack of torque can stem from hydraulic or mechanical issues:
Hydraulic system: Insufficient hydraulic oil pressure.
Mechanical failure: Damaged powerhead motor, gearbox, or transmission.
Low pilot pressure or improperly set relief valve pressure.
Powerhead motor failure or excessive hydraulic oil leakage.
Damaged components in the powerhead gearbox.
Mechanical failure in the powerhead transmission.
Check the hydraulic system’s main pressure. If normal, focus on mechanical issues.
Inspect the powerhead motor and output shaft—no issues found.
Disassemble the gearbox, ensuring cleanliness and proper disassembly sequence.
Identify and replace damaged gears, then reassemble the gearbox and motor.
A faulty gearbox can cause torque loss and unusual noises. Early detection prevents further damage.
The rope press is stuck and won’t rotate.
Severe wire rope wear.
Lack of lubrication leads to stiffness, deformation, or bearing failure inside the rope press, causing wire rope abrasion.
Insufficient lubricating grease inside the rope press.
Deformation of the rope press.
Damaged internal bearings are causing jamming.
Inspect the rope press for deformation—only surface wear found.
Open the rope press—lack of lubrication detected.
Further disassembly reveals damaged bearings.
Replace bearings, reassemble, and lubricate properly.
Regular lubrication prevents rope press failures and extends wire rope lifespan.
Oil leakage from the mast cylinder.
The mast does not remain vertical.
Possible causes include:
Broken piston rod head or damaged seals in the mast cylinder.
Internal leakage in the cylinder or balance valve failure.
Cracked mast piston joint.
Damaged mast cylinder seals.
Internal leakage in the balance valve.
Inspect the piston joint—cracks found.
Disassemble the cylinder—seals and O-rings are damaged.
Replace seals, O-rings, and gaskets, then reassemble.
Damaged seals lead to oil leaks and mast instability. Prevent wire rope contact with the piston rod to avoid damage.
The mast tilts during erection or lowering.
Mast cylinders move out of sync.
Possible causes:
Uneven solenoid valve opening.
Balance valve malfunction.
Internal cylinder leakage due to seal damage.
Adjust solenoid valve current—no improvement.
Clean and inspect the balance valve—no blockage found.
Disassemble the cylinder—damaged seals identified.
Replace seals—the mast operates smoothly.
Check electrical, hydraulic, and mechanical components when diagnosing mast synchronisation issues.
Severe rotation vibration at low engine speed.
Slight vibration at high speed.
Unstable pressure in Pump 1.
Possible causes:
Faulty rotation pilot circuit.
Unstable rotation relay.
Damaged rotation motor or main pump.
Check pilot pressure—normal, ruling out relay issues.
Test rotation motor—no impact on other functions.
Confirm main pump failure—replace the pump and the pilot pump.
Pressure fluctuations indicate pump failure. Prompt replacement restores performance.
Bored cast-in-place piles have the advantages of low construction noise, and low vibration, pile length…
Bored cast-in-place piles have the advantages of low construction noise, and low vibration,…
The four major construction technologies are dry hole forming technology, slurry static pressure technology, casing…
Soil nail support is a new type of retaining structure developed in recent years for…
Pile Foundation Classification and Construction Principles 1. Classification According to Load-Bearing Piles ① Friction type…
Steel sheet pile cofferdams are suitable for basic projects such as sandy soil, gravel soil,…
