Fault diagnosis and prevention of mechanical unlocking mechanism of drilling bucket

Ⅰ. Structure and failure mode

Mechanism composition and principle

The mechanical unlocking mechanism of drilling bucket is mainly composed of pressure plate nut, spring, protection frame, transmission rod, connecting rod, lock hook and other components. Its working principle relies on spring pressure to push the lock hook to close, and the transmission rod is linked to realize the unlocking action.

Typical failure modes include:

Mechanical jamming: silt accumulation or wear of the kinematic pair causes the rotation resistance of the lock hook to increase.

Spring failure: Fatigue or corrosion causes insufficient spring pressure and loose closure of the lock hook.

Structural damage: violent operation or impact load causes deformation of the connecting rod and breakage of the lock hook.

Environmental adaptability challenge

In underwater working environment, sand scoops need to frequently withstand high-pressure water flow impact and sand and gravel wear, and the unlocking mechanism is prone to corrosion fatigue: seawater or chemical additives accelerate the corrosion of metal parts.

Ⅱ. Technical path of fault diagnosis

Graded diagnosis strategy

Diagnostic method	Applicable scenario	Implementation points
Observation method	Preliminary inspection	Check spring deformation and lock hook wear
Function test	Verification after maintenance	Simulate unlocking action to test load capacity

Typical fault signal

Stuck phenomenon: abnormal increase in operating force, accompanied by metal friction sound.

Spring failure: The lock hook closes slowly or automatically pops open.

Ⅲ. Preventive maintenance system

Proactive maintenance plan

Spring detection: Measure the spring compression at irregular intervals, and replace it immediately if the deviation from the factory value exceeds 15%.

Sediment cleaning: Flush the inside of the mechanism after each operation to prevent siltation.

Operation specification optimization

Unlocking sequence: Remove the drill bucket load first and then operate the unlocking mechanism.

Ⅳ. Fault emergency handling process

Quick on-site disposal

Spring failure: Use spare spring module for quick replacement.

System repair strategy

Mild wear: Grind the contact surface.

Structural fracture: Replace the lock hook assembly as a whole and check the deformation of related components.

Ⅴ. Suggestions for full life cycle management

Design improvement direction

Use self-cleaning structure to reduce sediment adhesion, such as adding diversion groove design.

Modular design improves maintenance efficiency, and key components support rapid disassembly and assembly.

Balance between economy and reliability

Establish a fault database, count high-incidence fault modes, and optimize maintenance plans in a targeted manner.

Reduce downtime losses through preventive maintenance.