The hydraulic system is mainly composed of hydraulic oil, hydraulic system, hydraulic system, hydraulic system and so on. It has the advantages of compact structure, flexible operation, smooth operation and convenient operation. The hydraulic system is a hydraulic system. As the transmission power of the media, because the internal components of the wear and tear after the wear, accompanied by overheating, work and other failures. The occurrence of hydraulic transmission failure is sudden, concealed, and involves more components, to the fault diagnosis and troubleshooting to bring some difficulties, so the maintenance of hydraulic systems, we must understand the working principle and the correct analysis of the cause of the malfunction On the basis of the quality of maintenance to ensure that. In this paper, PC200-5 excavator often as an example of failure, introduced the working principle of hydraulic transmission, analysis of its common fault diagnosis and troubleshooting methods.

1 PC200-5 excavator hydraulic system works

PC200-5 excavator hydraulic system is composed of some basic circuit and auxiliary circuit, which includes the working circuit, pressure limiting circuit, unloading circuit, buffer circuit, throttling speed and throttling speed limit circuit, speed limit circuit and Pilot valve control circuit and so on. Its components mainly by the working pump, charge pump, pilot control valve, distribution valve, safety valve, arm cylinder, arm cylinder, bucket cylinder, fuel tank and related pipelines and other components.

PC200-5 excavator hydraulic system in the course of work, the hydraulic oil from the bottom of the tank through the oil filter by the working pump inhalation, from the pump output with a certain pressure of hydraulic oil into a group of parallel distribution valve. Through the handle - → pilot valve - → working valve group to achieve the corresponding action, the system through the total oil on the total safety valve to limit the total pressure of the entire system, the working oil safety valve of the respective oil circuit overload protection and Replenishment effect.

Fault Diagnosis and Elimination of Hydraulic System of PC200-5 Excavator

PC200-5 excavator, the hydraulic system of the set pressure of 30MPa, less than the pressure of the system pressure is low. The failure of the hydraulic system is mainly manifested in two aspects: the arm lift is slow and weak; The main cause of the two failures is the low working pressure, and the main reason for the low pressure is clogging and leakage. Oil flow, sealing is a good system to ensure that the work, congestion and leakage is the most common hydraulic transmission failure, so check the hydraulic drive failure generally from the hydraulic circuit began to check. The following is a description of the different fault phenomena in the hydraulic system.

2.1 arm lift slowly weak, and other actions are normal