Troubleshooting on Dump Truck Tipping Failures
l COMMON FAULTS AND THEIR CAUSES
1. The cylinder lifting problem .The faulty reasons may as following:
l lack of fuel
l a serious blockage or pipe filter tank
l pump malfunction, not oil
l lift switch blocked, the oil return valve distribution valve stuck in the back to the oil return valve position.
l a serious imbalance in the relief valve, high pressure pump leakage
l lifting cylinder and valve limit, leading valve of the gas distribution of long-connected
l cylinder pressure
l PTO, oil pump gears faulty works
l dirty hydraulic oil, impurities in distribution valve
2 The cylinder telescoping in slowly lifting speed. The faulty reasons may as following:
l oil does not flow back or large friction in lifting cylinder
l lifting cylinder strictly limit the valve seal, seal ring of the lifting cylinder, resulting in lack of oil pressure
l gear pump reduces efficiency, less fuel tank, gear pump is not under the row over oil
l pipe serious leak.
3 Heavy duty lifting limited. The faulty reasons as following:
l severe overloading
l vehicles parked on the ramp to move heavily
l much lower oil viscosity
l piping, valves, tanks are leak failure.
4 Truck lifted themselves after falling. The faulty reasons as following:
l catching one-way valve
l sealing bad lifting cylinder
l distribution valve catching and not fully in place;
l pipe leaks.
5 Tipper trucks do not fall
Main pressure is not enough to make the oil return valve distribution valve action, or limit the valve pipe damage, and the lifting cylinder lift switch catching.
6 Truck lift cannot stop in any position
More for the oil too dirty, so check parts, or distribution of valves, valve oil return.
l Check whether there is sufficient dump truck oil in the plane, should be required to be added is insufficient.
l View power take control mechanism is working properly, oil and gas lines are seamless osmosis, if necessary, should be inspected for blockage.
l Check the pumps, distribution valves, limit valve, etc. is good, lifting cylinder is sealed, if necessary, be repaired. Manipulation of the valve control system moves the various failure and should be replaced with new parts.
l Dirty hydraulic fluid, causing blockage or hydraulic oil shortage and slow, not in place inside liters of hydraulic oil should be replaced.
l Oil pump gear shaft drive mechanism or damage to, dump trucks cannot operate and the internal leakage is severe, replacement parts should be repaired.
MAINTENANCE OF HYDRAULIC SYSTEM
l The main oil pump, driven gear journal and bearing wear, it will lead to increased engagement gap, resulting in decreased displacement pump, working steadily decreased, resulting in noise.
l After the journal and bearing wear gear with the pump chamber will cause changes in radial clearance, resulting in gear pump chamber relative to the corresponding center of the center line into the oil chamber side to offset radial prone work, and make some regional variations large part of the area smaller.
l Large gap caused by leakage, pump flow and pressure drop; and a small gap will make the addendum collision and friction, causing damage to the pump chamber.
l And pump gear end cap or end bearing wear, scratches, and from the slot, it will cause internal pump chamber and out of the oil leakage, the circuit increases, so the oil chamber from leaking through the loop and into the oil chamber of the oil increased, pump pressure and flow down.
l Found out that the erosion damage caused by failure to identify the reasons, the immediate replacement parts repair.
POINTS OF THE HYDRAULIC SYSTEM OVERHAUL
l Decomposed assembly apart, parts should be carefully placed in the wash and clean the oil immersion, should not bump and scratches, very important parts cleaning, assembly of non-metal impurities into the dirt and to avoid increasing mechanical wear and tear, the card stagnation and failure.
l Strictly in accordance with the work of selection and processing enough oil, if necessary, filter to ensure clean oil; the use of the system should be no leakage.
l Maintenance when the percussion parts should be avoided to prevent damage deformation of parts.