1. Choosing the right hydraulic oil plays the role of transmitting pressure, lubrication, cooling and sealing in the hydraulic oil system. Improper selection of hydraulic oil is the main reason for the early failure and the decline of durability of the hydraulic system. The hydraulic oil should be selected according to the grade specified in the random "Instruction Manual". When special circumstances require the use of alternative oil, the performance should be the same as the original grade.
2. Precautions for regular maintenance At present, some engineering machinery hydraulic systems are equipped with an intelligent device. This device has a warning function for some hidden problems in the hydraulic system, but its monitoring range and accuracy are limited. Combine the monitoring results of intelligent devices with regular inspection and maintenance.
(1) 250h inspection and maintenance Check the attachments on the filter screen of the filter, such as excessive metal powder, which often indicates the wear of the oil pump or the pulling of the oil cylinder.
(2) 500h inspection and maintenance After the construction machinery is operated for 500h, it should be replaced regardless of the condition of the filter element, because it is difficult to detect the small damage of the filter element with the naked eye. If the high temperature operation for a long time, the filter element should be replaced in advance.
(3) 1000h inspection and maintenance At this time, the filter should be cleaned, the hydraulic oil tank should be cleaned, the filter element and hydraulic oil should be replaced, and the oil change time should be properly advanced for long-term high temperature operation.
(4) 7000h and 10000h inspection and maintenance The hydraulic system of the construction machinery at this time needs to be inspected by professionals to make necessary adjustments and repairs. According to practice, imported hydraulic pumps and hydraulic motors must be overhauled after working for 10000h, otherwise the hydraulic pumps and hydraulic motors may be damaged due to disrepair, which is fatal to the hydraulic system.
3. It is the life of the hydraulic system to prevent solid impurities from mixing into the clean hydraulic oil of the hydraulic system. There are many precision couples in the hydraulic system, and some are equipped with damping holes or gaps. Intrusion of solid impurities will cause strain on precision parts, card issuance, blockage of oil passages, etc., endangering the safe operation of the hydraulic system.
4. Prevent air and water from invading the hydraulic system
(1) Prevent air from intruding into the hydraulic system. At normal pressure and temperature, the hydraulic oil contains air with a volume ratio of 6% to 8%. When the pressure is reduced, the air will be released from the oil. The air bubbles will rupture and cause the hydraulic components to "cavitation" noise. A large amount of air entering the oil will aggravate the "cavitation" phenomenon, increase the compressibility of the hydraulic oil, work unstable, reduce the work efficiency, and cause undesirable consequences such as "crawling" of the actuator. In addition, the air will oxidize the hydraulic oil and accelerate its deterioration.
(2) Prevent water from invading the hydraulic system. Excessive moisture in the hydraulic oil will rust the hydraulic components, emulsify and deteriorate the oil, reduce the strength of the lubricant film, and accelerate mechanical wear. In addition to preventing water intrusion during maintenance, it is also necessary to tighten the lid when the oil storage barrel is not in use. It is best to place it upside down; hydraulic oil with a large water content must be filtered many times, and the dried filter paper should be replaced every time the filter is filtered. When there is no special instrument for testing, hydraulic oil can be dripped onto the hot iron plate, and no steam will emerge and burn immediately before filling.
