1. The selection of suitable hydraulic oil plays the role of pressure transmission, lubrication, cooling and sealing in the hydraulic oil system. Inappropriate selection of hydraulic oil is the main reason for the early failure and durability of the hydraulic system. The hydraulic oil shall be selected according to the brand specified in the random "Operation Manual". When the substitute oil is required in special circumstances, its performance shall be the same as that of the original brand.

2. Precautions for regular maintenance At present, some hydraulic systems of construction machinery are equipped with intelligent devices. The devices have warning functions for some hidden dangers of hydraulic systems, but their monitoring scope and accuracy have certain limitations. Therefore, the inspection and maintenance of hydraulic systems should combine the monitoring results of intelligent devices with regular inspection and maintenance.

(1) 250h inspection and maintenance Check the attachment on the filter screen, such as excessive metal powder, which often indicates that the oil pump is worn or the oil cylinder is pulled.

(2) 500h inspection and maintenance of construction machinery after 500h operation, regardless of the condition of the filter element should be replaced, because it is difficult to detect the small damage of the filter element by naked eyes, if long-term high temperature operation should also be appropriate to replace the filter element 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 the hydraulic oil should be replaced, and the oil change time for long-term high-temperature operation should be appropriately advanced.

(4) 7000h and 10000h inspection and maintenance of the hydraulic system of construction machinery at this time shall be inspected by professionals and necessary adjustment and maintenance shall be carried out. 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 a fatal damage to the hydraulic system.

3. Prevent solid impurities from mixing into the hydraulic system. Clean hydraulic oil is the life of the hydraulic system. There are many precision coupling parts in the hydraulic system, some of which are provided with damping holes or gaps. Intrusion of solid impurities will cause strain of precision coupling parts, blockage of hairpin and oil passage, which will endanger the safe operation of hydraulic system. (The most technical is WeChat's most powerful technical information platform. Pay attention to the most technical if you like! Search for the most technical or man-machine attention.)

4. Prevent air and water from invading the hydraulic system

(1) to prevent air intrusion in the hydraulic system at normal pressure and room temperature, the hydraulic oil contains a volume ratio of 6% to 8% of the air, when the pressure is reduced, the air will be free from the oil, the bubble burst so that the hydraulic components "cavitation", resulting in noise. A large amount of air entering the oil will aggravate the phenomenon of "cavitation", increase the compressibility of hydraulic oil, work instability, reduce work efficiency, and implement components "crawling" and other adverse consequences. In addition, the air will oxidize the hydraulic oil and accelerate its deterioration.

(2) to prevent water intrusion hydraulic system hydraulic oil containing excessive moisture will make the hydraulic components rust, oil emulsification deterioration, lubricating oil film strength decreased, accelerate mechanical wear. In addition to preventing water intrusion during maintenance, it is also necessary to tighten the lid of the oil storage barrel when not in use, and it is best to place it upside down. Hydraulic oil with high water content should be filtered many times, and the dried filter paper should be replaced every time it is filtered. When there is no special instrument for detection, the hydraulic oil can be dropped on the hot iron plate, and no steam can be emitted and burned immediately before filling.