1. Simple fault diagnosis method
(1) ask the equipment operator to understand the operation status of the equipment, including: whether the hydraulic system works normally; whether the hydraulic pump is abnormal; the time and results of hydraulic oil cleanliness detection; the cleaning and replacement of filter element; whether the hydraulic element is adjusted before the failure; whether the sealing element has been replaced; and what abnormal phenomena have occurred in the hydraulic system before and after the failure ； What faults have occurred in the system in the past and how to eliminate them need to be understood one by one.
(2) look at the actual working conditions of the hydraulic system, and observe whether there are problems in system pressure, speed, oil, leakage, vibration, etc.
(3) listen to the sound of the hydraulic system, such as impact sound, pump noise and abnormal sound; judge whether the hydraulic system works normally.
(4) Touch the temperature rise, vibration, crawling and the tightness of the connection to determine whether the working state of the moving parts is normal.
In short, the simple diagnosis method is only a simple qualitative analysis, which has a wide range of practicability for rapid judgment and troubleshooting.
2. Schematic analysis method of hydraulic system
According to the schematic diagram of the hydraulic system, the faults of the hydraulic transmission system are analyzed, the positions and causes of the faults are found out, and the troubleshooting methods are put forward. Hydraulic system diagram analysis method is the most common method used by engineers and technicians at present. It requires people to have a certain foundation for hydraulic knowledge, understand the hydraulic system diagram, master the name and function of the components represented by various graphic symbols, and have a certain understanding of the principle, structure and performance of the components. With such a foundation, combined with the action cycle table for comparative analysis It's easy to judge the fault. Therefore, carefully studying the basic knowledge of hydraulic pressure and mastering the hydraulic schematic diagram is not only the most powerful assistant for fault diagnosis and troubleshooting, but also the basis of other fault analysis methods.
3. Other analytical methods
When a fault occurs in the hydraulic system, it is often impossible to find out the location and root cause of the fault immediately. In order to avoid blindness, people must carry out logical analysis according to the principle of the hydraulic system or eliminate it one by one by means of causal analysis, and finally find out the location of the fault, which is to find the fault by using the method of logical analysis. In order to facilitate the application, the fault diagnosis expert designs the logic flow chart or other charts to judge the fault logically, which provides convenience for fault diagnosis.
