Common faults of truck crane and its treatment

phenomenon

Analyze the reasons

Treatment method

Truck crane does not work

Pump does not work

1 , the power handle is not pushed into place

1 , push the power handle into place

2. The gear in the power take-off box appears damaged

2 , overhaul power box

3 , The damage of the drive sleeve between the output shaft of the power take-off box and the input shaft of the oil pump

3 , replace the drive sleeve

4 , oil pump burned

4 , replace the oil pump

Pump work but no pressure oil

1 , lack of oil tank

1 , add enough hydraulic oil

2. The oil filter is blocked

2 , cleaning oil filter

Loss of lifting capacity, clearly failing to meet regulatory requirements

Hydraulic system pressure is too low

1 , the system leaks

1 , check all the pipes and components and take measures to stop leaks

2. The pressure of the overflow valve is too low

2. Check the relief valve setting pressure (The specified relief valve setting pressure is 14Mpa (2~3 tons of crane)/17.5Mpa (5~8 tons of crane). Over-regulation is not allowed) If the relief valve loses pressure regulation When in effect, the overflow valve should be checked and replaced and damaged parts replaced

3 , reduce the volumetric efficiency of the oil pump

3 , replace the oil pump

Lever cylinder

1. The inner leakage is increased due to the damage of the inner ring of the cylinder

1 , replace the damaged seals and piston

2. Deformation of the piston in the variable cylinder or deformation of the cylinder cylinder of the cylinder, resulting in large internal leakage

2 , check the cylinder deformation

Retractable cylinder is weak

Same as above

Same as above

Winning power

Winch plunger oil motor reduces volumetric efficiency

Replace the oil motor

After the goods are lifted, they are naturally reduced (more than 2mm/min). It can be clearly seen that the variable piston rod is pulled out, the movable arm and the leg are significantly retracted, and the lifting hook is naturally declining.

1 , variable cylinder, telescopic cylinder, internal cylinder leakage

1 、 See the above article for treatment methods of internal leakage in cylinder

2. Destruction of balance valve and cylinder of balance cylinder

2 , replace or repair balance valve

3 , bidirectional hydraulic lock at the leg breaks

3 , replacement or overhaul bidirectional hydraulic lock

4) The volumetric efficiency of the hoisting motor is reduced, and the friction brake discs in the hoisting gearbox are destroyed

4 , replace the friction brake pad and the motor