Maintenance essentials of hydraulic system

There are various construction machinery active on the construction site. Hydraulic excavator is one of the most important equipment of these construction machinery, and hydraulic system is one of the most important systems of these equipment. For the fully hydraulic excavator, it can be said that the hydraulic system, like the blood circulation system of the human body, is distributed throughout the excavator. It includes the hydraulic oil tank, main pump, multi-way valve, various pipelines and the oil cylinder, motor and other components that perform various actions. These hydraulic components are precision processed, and they have high requirements for the maintenance of the hydraulic system. If the maintenance is improper or not maintained, it will lead to failure, This will cause the machine to stop and bring you losses

Three main points to keep the hydraulic system clean
When hydraulic oil enters the hydraulic system for operation, cleaning is the primary problem. Dirt and other impurities shall be prevented from entering the system
If tiny particles of impurities enter the hydraulic system, they will scratch the pump, block the valve and block the oil port, thus causing machine failure
How to keep the hydraulic system clean
There are three main points:
◆ Keep the hydraulic oil clean
◆ Keep the system clean
◆ Keep the working area clean

Keep the hydraulic oil clean
Store the oil in a clean place. Be careful when changing or adding oil. Only use a clean funnel equipped with a fine mesh filter to pour oil from the container into the tank. Of course, the oil you use must be the type recommended by Hitachi Construction Machinery< br /> It is recommended that you use Hitachi pure oil
HP46 Hitachi pure oil, which can be used for 4000 working hours under normal operating conditions, has been added to Hitachi machines when they leave the factory

Keep the system clean
(1) Replace the hydraulic oil and filter regularly
Good hydraulic oil contains a variety of additives, which can prevent oil deterioration
However, these additives will lose their effectiveness after a period of time. Therefore, the oil should be replaced regularly to ensure that the additives play a role
The filter can only absorb a limited amount of dirt particles and other impurities from the oil
For Hitachi ZX series (medium) machines, please replace the oil return filter of the hydraulic tank every 1000 working hours, and clean the oil suction filter of the hydraulic tank when replacing the hydraulic oil to keep the system clean
When replacing the hydraulic oil filter, check whether there are metal particles or debris at the bottom of the filter; If there is copper or iron filings, it indicates that the hydraulic pump, hydraulic motor or valve may be damaged or will be damaged. If there is rubber, it indicates that the hydraulic cylinder seal is damaged

(2) Drain the oil tank dirt regularly
It is very important to drain the water and sediment in the oil tank regularly to remove impurities in the oil, but it is also important to replace the hydraulic oil in the entire hydraulic system regularly. This is the only reliable way to completely remove system impurities, oxidized hydraulic oil and other harmful impurities. Then, clean hydraulic oil recommended by Hitachi Construction Machinery should be added to the hydraulic system again
Please drain the dirt in the hydraulic tank sump every 250 working hours
(3) Cleaning
If the hydraulic oil is contaminated, especially when the pump or oil cylinder or motor is damaged, all the hydraulic oil must be replaced and the oil tank must be cleaned

Keep the working area clean
When adding hydraulic oil to the oil tank or refilling hydraulic oil, ensure that the area around the filter tank cover is clean
Use only clean funnels or containers< br /> Do not bring dirt into the system
When maintaining the hydraulic system, only clean plastic plugs can be used to seal the end of the pipeline
When maintaining hydraulic components, the workbench must be absolutely clean
Check the condition of the tools used. They should also be very clean.