Due to damage or improper operation of hydraulic components, wheel excavator hydraulic system pollution is easy. The treatment method of hydraulic system pollution is described as follows for reference.
1.On-site inspection of contamination of mainframe
First check whether the metal shape on the inner filter element and magnetic rod of hydraulic oil return filter is flake or strip. Metal sheet contains copper metal, mainly due to hydraulic main pump, rotary motor or walking motor internal bearing damage. The metal strip is mainly caused by the internal damage of each hydraulic cylinder and operation valve group including valve core valve sleeve.
2.Preparation before processing
1)First of all, observe whether the excavator parking site is flat and the size of the surrounding dust, when the excavator can drive, it should be parked in a flat terrain, less dust, if there are conditions, it is best to park indoors.
2)Unfold and fix the excavator operation device, and pay attention to safety in the later repair process.
3)Prepare two empty oil drums, remove the servo gear pump inlet oil pipe joint, use servo pump inlet oil pipe to drain the hydraulic oil in the hydraulic tank, and use the empty oil barrel to connect the oil.
4)Prepare a hoisting equipment.
5)It is best to prepare an air compressor to facilitate the cleaning of hydraulic systems.
6)On-site preparation for oil cleaning petrol or kerosene and oil basins.
3.Remove hydraulic components
1)Platform segment
Remove the hydraulic tank, main pump, operation valve group, return oil filter assembly, rotary motor assembly respectively.
2)Operating unit
Remove the bucket rod hydraulic cylinder. The arm hydraulic cylinder and bucket hydraulic cylinder need not be removed, can be decomposed, checked and cleaned on the whole machine.
3)Chassis section
Remove the leg hydraulic cylinder and walking motor respectively.
When disassembling the above hydraulic parts, the pipes should be recorded separately, and the pipes should be wrapped to prevent dust from entering. The disassembled parts should be transported to the indoor or dust-free place for inspection, cleaning and repair. Because the pipeline is more, when disassembling make a good mark, when connecting the pipeline is not easy to make mistakes.
4.Repair and cleaning of hydraulic components
1)Operating valve group
Check. Disintegrate the valve group, check the valve body, stem, valve core, valve sleeve and other components to see if there is serious tension, card issuing phenomenon. If the component damage is serious, the assembly must be replaced.
Cleaning. Remove all stem and spool in valve group. Clean with cleaning oil from top to bottom, then clean with compressed air from top to bottom. After cleaning, add lubricating oil to prevent rust, stem, spool, valve sleeve and other components need to be repaired and cleaned separately.
Assembly. After cleaning the valve stem, valve core and other components are assembled separately, installation must be added lubricating oil, the valve group outside all relevant connection lines, joints for cleaning and installation. The oil inlet of the external pipe joint is bandaged to prevent dust from entering.
2)Rotary motor and walking motor
Check the oil distribution mechanism, variable mechanism whether pull injury. If there is a slight strain can be field grinding treatment. Check if the piston rod, piston cylinder is pulled, if the above parts are damaged and the strain is serious, the assembly must be replaced.
Cleaning assembly. Clean the parts in the motor with cleaning oil, add lubricating oil and assemble.
3)Hydraulic cylinder
Check hydraulic cylinder piston rod, seal, buffer sleeve, cylinder block internal damage, if serious damage must be replaced assembly. Cleaning assembly.
Wash the internal parts of the hydraulic cylinder with cleaning oil, assemble after cleaning, pay attention to the opening direction of the piston support ring when assembling.
4)Central rotary joint
Because the central rotary joint is not removed from the main engine, the cleaning oil can be poured into the upper tubing for washing, and the bottom can be caught with an oil basin.
5)Hydraulic oil tank
Clean the tank, replace the oil filter, and replace the servo filter.
5.Component assembling
Install the cleaned parts separately and connect the hydraulic pipe. The hydraulic pipe connection of the moving arm hydraulic cylinder, the bucket hydraulic cylinder, the bucket hydraulic cylinder and the leg hydraulic cylinder must be to connect the large and small cavity intake pipe, and the inlet pipe of the walking motor and the return pipe, so that in the next step of the internal circulation, the pipe of the cleaning operation device and the walking motor pipe on the central rotary joint.
6.Internal circulation
1)Add hydraulic oil after installation of the system. During the process of adding hydraulic oil, check whether there is oil leakage in each connection line, and pay attention to the main hydraulic pump, rotary motor must discharge air.
2)After the completion of the above work, the following operations are carried out:
Start the engine, check again whether the connection lines of the whole machine are leaking, running empty, do not operate any action to observe 20 minutes after shutdown, mainly clean the operation valve group and the intake pipeline and hydraulic oil radiator, Check the metal chips on the oil filter rod and clean the return pipeline in the same way until there is no metal chips on the oil filter rod.
Individual internal cycle cleaning:
Arm: only single operation arm control handle, clean the arm large, small cavity pipeline and operation valve internal oil circuit, check the return oil filter magnetic rod, until the return oil filter magnetic rod without metal chips.
Bucket rod, bucket, rotary motor, walking motor, leg are treated in the same way.
Connect the moving arm hydraulic cylinder, bucket rod hydraulic cylinder, bucket hydraulic cylinder, rotary motor, walking motor, leg hydraulic cylinder to connect the tubing, carry on the whole machine body circulation, the engine speed is controlled at medium and low speed, check the return oil filter magnetic rod until there is no metal chip on the return oil filter magnetic rod.
After the above method is finished, the whole machine is cleaned by compound action, and the oil filter magnetic rod is checked every 15 minutes to know that there is no iron chip on the oil filter magnetic rod.
After the method is processed, check whether the pressure of the whole machine is correct.
After all the above work is done, the oil filter and servo filter must be replaced.
7.Proper maintenance
After the system is processed, the user operates, and the engine throttle is controlled at medium speed in the next 100 hours. At the beginning of 20 hours, check the return oil filter magnetic rod every 2 hours, then check the return oil filter magnetic rod once a day after 100 hours to replace the return oil filter core, clean the servo filter core.