First, the repair conditions and content of the hydraulic system
Hydraulic components are precision machine components and can only be repaired by experienced personnel with precision machining equipment and technical level.
(1) Required repair conditions
A. Repair personnel must have the corresponding technical level;
B. There are replaceable spare parts;
C. There are parts for repair
D. There is a corresponding test bench.
(2) Contents of repair
A. Minor repairs (maintenance repairs, that is, on-site repairs where the hydraulic system fails during commissioning or operation). No replacement of parts, only light machining (throwing, grinding, grinding, scraping) on the original parts. Mainly for oil leakage of various valves, pipes, and component planes, replacement of seals, etc. In addition, it also refers to the selection and replacement of pressure regulating springs of pressure valves of the same model and different pressure levels.
B. Intermediate repair. Refers to the replacement of journal oil seals, bearings, piston rod seals and valve stem oil seals.
C. Overhaul (restorative repair). Replace worn parts (in pairs). However, the cylinder barrel and piston rod of the hydraulic cylinder cannot be replaced.
It must be explained: the "minor repair", "medium repair" and some "overhaul" projects of concrete batching plants carried out by our factory are all based on the replacement of components and some parts, and generally cannot prepare parts for hydraulic components by themselves. 2. Cleaning of hydraulic equipment
1. Training school for cleaning costers of parts and components
(1) Parts and components are generally cleaned with kerosene in the factory, but gasoline is prohibited.
(2) Hydraulic hoses can be sprayed with high-speed liquid flow, and hard pipes can also be cleaned in the same way.
(3) If the hydraulic components have been cleaned before leaving the factory and the oil ports are sealed with plastic plugs, as long as the storage time does not exceed two years, it is not necessary to clean the inside of the components.
(4) Ultrasonic cleaning is used for parts of high-precision hydraulic components such as servo valves. 2. Cleaning of the hydraulic system The hydraulic system must be cleaned after the first installation; it should also be cleaned according to the actual situation before commissioning after overhaul.
The general steps of hydraulic system cleaning are as follows:
(1) Select cleaning oil: when the system pipeline oil tank is relatively clean, it can be cleaned with the same viscosity or the same oil as the working oil; if it is found that the system is not very clean, a slightly lower viscosity cleaning oil can be used for cleaning .
(2) Heating and cleaning oil: Hot oil makes the attachments in the system easy to fall off. Generally, it is heated to 50 ~ 60 ℃, the cleaning pressure is 0.2 ~ 0.4Mpa, and the cleaning oil flow rate is as large as possible, so as to help take away the dirt.
(3) Install filter: In the cleaning circuit, install a 50-100μ coarse filter at the oil inlet, and a 10-50μ filter at the oil return port. Roughly filter at the beginning, and gradually switch to a fine-mesh oil filter after rinsing for a period of time, and filter in stages. The cleaning time is generally 8 to 24 hours. Start to disassemble the oil filter every half an hour for cleaning, and gradually replace the filter element with fine mesh and extend the cleaning time interval. The equipment with serious pollution should be cleaned with low-viscosity oil with good cleaning effect first. Then use cleaning oil with a viscosity similar to the oil used for cleaning.
(4) Tap with a wooden hammer while cleaning, which can promote the speed of contaminant shedding. The bending and welding parts of the pipeline should be struck more, but the force should not be too strong, so as to avoid the deformation and rupture of the pipe.
(5) Drain cleaning oil: After cleaning, remove the cleaning oil as much as possible, including the cleaning oil accumulated in the pump, valve, pipeline and cooler. The pipeline can be loosened, and the cleaning oil can be taken away by blowing with compressed air or adding working oil.
(6) Add new hydraulic working oil: After the cleaning oil is removed, new hydraulic oil should be added as soon as possible, and a short-term test run should be carried out immediately to avoid corrosion in the pipeline and other adverse effects.
