Vibration and noise troubleshooting of crane hydraulic system

The vibration and noise of small crane hydraulic system is produced at the same time, the main reasons for this failure: one is caused by fluid pulsation, if there is more oil in the air, small crane pump flow ripple, trapped oil phenomenon is not well eliminated, pump and control valve and other hydraulic components failure; mechanical vibration is two cause, such as the slender pipe fixation caused by vibration, vibration caused by the pump drive shaft and the drive shaft are concentric etc..

Vibration and noise troubleshooting of crane hydraulic system

The hydraulic system penetrated into the air and other reasons, and also made the actuator inhomogeneous movement - crawling. The air source may have a low oil level, oil suction pipe resistance is too large (such as tubing or clogged filter, etc.), the oil pipeline without clamping etc.. Only by adopting one by one division method, we can find out the causes of vibration and noise, eliminate the air in the hydraulic system, eliminate the oil trapped oil and replace the long and long pipes that cause vibration, and fix the long pipelines, so that we can get rid of the trouble. Some common troubleshooting of small cranes, reasons and elimination methods are as follows:

1. oil pump is not out of oil

The oil tank is too low, the direction of rotation is wrong, the oil suction pipe is leaking, and the hydraulic oil is too sticky. Elimination method: add foot oil, change the direction of pump rotation, eliminate gas leakage, change the qualified new oil.

2. oil pressure or insufficient displacement of oil pump

Cause: safety valve failure; oil pump wear seriously; gear wear gap is too large.  Troubleshooting: repair and repair each part of the safety valve; repair or replace the oil pump; adjust the gap.

3. the pressure of the oil pump is unstable or the vibration is severe

Cause: oil is not enough or air is inhaled; there is friction between the gear and the surface of the shell. Removing methods: refueling, eliminating air leakage, replacing gear.

4. insufficient oil supply or broken oil for hydraulic oil pump

Reason: the pump suction pipe deformation, channel becomes smaller or blocked; bearing damage, the gear pump body caused by scraping the gap is too large and serious leakage; damage of gear, gear and pump stuck; pump plunger and cylinder wear or the oil pan sealing area and bad seal. Elimination method: remove clogged dirt, change new tube, light replacement bearing, gear, pair repair and grinding plunger pair, serious change pump.

Oil leaking of 5. small crane oil cylinder

Cause: the seal ring is damaged or worn. Exclusion method: change.

6. the inner cavity of the oil cylinder of the small crane often produces gas

Reason: the oil contains water; the oil pump inlet pipe is leaking; the oil quantity is insufficient. Elimination method: replace the new oil, eliminate water failure; tighten the joint; fuel the oil tank according to the required oil level.

7. small crane oil cylinder motion retardation

Reason: there is air in the oil tank. Elimination method: eliminate air.

8. small crane oil cylinder does not move smoothly or even

Cause: oil seal of oil cylinder is too tight or oil seal is deteriorated. Elimination method: the oil seal is adjusted loosely so that the oil does not leak out, or the oil seal is replaced.

Automatic retraction of hydraulic cylinder of 9. small crane

The reason is: the piston sealing ring is damaged; the spring on the one-way spool of the two-way hydraulic lock is damaged; there is dirt on the spool and seat surface of the one-way valve and the valve seat scratches, and the one-way spool has cracks; the check valve in the balancing valve is not closed. Exclusive method: replace Xinmi sealing ring; dismantle and clean two-way hydraulic lock, remove dirt; replace damaged spring and cracked one-way valve assembly; repair or replace the one-way valve spool which is closed in balance valve.

10. hydraulic cranes manipulate the multipath reversing handle when the actuator is weak or slow, and the movement is bad.

The reason: a multi way reversing valve, safety valve pressure adjustment was low; safety valve spring damage or permanent deformation; conical valve damage; control valve and hole wear or adverse action; amplitude control valve group, pressure relief valve function expansion manipulation or control windlass operating pressure and rotary control the operating pressure or improper adjustment of one-way valve dysfunction.

Troubleshooting: pressure meter for detecting the pressure of the hydraulic system, if the lack of pressure, the safety valve should be adjusted, so that the pressure reaches the specified value; check valve spring, when necessary for new; re grinding valve leakage or valve cone; check valve, internal leakage is serious, new stem or stem re chrome configuration; if the stem and the body is stuck, open the cleaning, removal of foreign body, spring break, the replacement of the new spring, re assembly, the valve stem flexible movement; valve set pressure relief valve will be transferred to the normal value, repair or replace the valve.

11. small crane accumulator storage pressure drop or effect failure

Cause: leakage of hydraulic oil; drop of nitrogen pressure; damage of air bag. The elimination method: replace the O shape seal ring, gasket and gasket, repair the leaky pipe joint, remove the charging valve spool and the valve body (first slowly release the nitrogen in the air bag before the demolition, reduce the nitrogen pressure to zero), carry out cleaning, remove foreign matter, and replace accumulator.