Excavator fault exclusion

Excavator fault exclusion Abstract: the hydraulic system is one of the most important system of excavator, also is one of the most prone to fault system, this paper, taking PC200-5 type excavator hydraulic system as an example, tells the story of the hydraulic system working principle and failure diagnosis and elimination method, for the excavator and other contains hydraulic transmission equipment maintenance play a guiding role. Keywords: the troubleshooting of excavator hydraulic fault Excavator on the application of hydraulic transmission system mainly has the pilot control hydraulic system, rotary walking hydraulic system, hydraulic system, working device hydraulic system, etc., it has compact structure, flexible motion, smooth operation, the advantages of convenient operation, the hydraulic system in hydraulic oil as the transfer medium of power, will leak after wearing, because of the internal components at the same time accompanied by overheating, unable to work, etc. The emergence of the hydraulic transmission fault is sudden, concealment, and components is more involved, bring certain difficulty to failure diagnosis and elimination, so in the maintenance of the hydraulic system, must understand its working principle and correct based on the analysis of the cause of the problem to guarantee the quality of maintenance. In this paper, the principle of hydraulic transmission is introduced in this paper, and the diagnosis and elimination method of the common fault phenomena are analyzed. 1 pc200-5 excavator hydraulic system working principle PC200-5 type excavator hydraulic system is composed of some basic circuit and auxiliary circuit, they include working loop, pressure limiting circuit, unloading, buffer circuit, throttling control of motor speed and throttling speed loop, walking speed loop and the guide valve control circuit, etc. Its components work mainly by the pump, oil pump, pilot control valve, distributing valve, safety valve, the big arm oil cylinder, lower oil cylinder, bucket cylinder, fuel tank and related piping, etc. PC200-5 type excavator hydraulic system in the process of work, the hydraulic oil pump suction from the bottom of the tank through the oil filter is work, from the pump output has certain pressure of the hydraulic oil into a set of parallel distributing valve. Work through the handle - - pilot valve - - valve group to implement the corresponding action, the system by the total on the total oil relief valve caps the total pressure of the system as a whole, each work oil relief valve respectively to overload protection and oil compensating effect to the corresponding oil. Pc200-5 excavator hydraulic system failure diagnosis and exclusion The pc200-5 excavator, the pressure of the hydraulic system is 30MPa, less than the pressure is low. The failure of the hydraulic system mainly manifests itself in two aspects: the rise of the big arm is slow and weak; The rotation is slow and weak. The main cause of two failures is the low pressure on the job, and the main cause of low stress is congestion and leakage. Sealed oil flow, is the guarantee for normal work of the system, plug and leak is the most common hydraulic transmission failure, so check the hydraulic transmission failure usually start from the aspects of hydraulic circuit inspection. The following is the diagnosis and elimination method of different fault phenomena of hydraulic system. The 2.1 arm lifted slowly, while the other movements were normal Fault diagnosis for 2.1.1 In the hydraulic system, if the arm is only raised slowly and slowly, the turning is normal. From the working principle of the figure is not hard to see: other work is normal, this means working pump, total safety valve is working, they provide to the pressure of the whole system is enough, at the same time, it shows that the pump inlet end line and the oil filter, and the amount of oil, no problem of oil tank. Just check the big arm slide valve, the big arm oil cylinder, the big arm part of the tubing, and the sealing part. (1) check the oil road congestion Make regular processing first, remove the tubing, remove the big arm slide valve body, valve stem and related parts for cleaning, clean the oil way and use compressed air to blow dry. (2) check the oil spill The leakage of the hydraulic system is usually produced after a period of time. On the surface, it is caused by the failure of sealing parts, damage, extrusion or sealing surface. The main reasons are: the oil pollution, improper seal surface roughness, sealing groove is unqualified, loose coupling, with a clearance increases, the oil temperature is too high, and poor sealing ring spoiled or assembly, etc. Leakage is divided into internal leakage and leakage, usually caused by internal leakage. (3) the handling of the internal leakage failure The leak in the department is mainly caused by the sliding valve and the oil cylinder. Internal leakage occurs mainly in body and oil cylinder, not easy to check. But we can use some helper methods to determine the leak. (4) examination of the large arm oil tank When the piston of the large arm cylinder receives the bottom, remove the rod without the rod, make the big arm oil cylinder have the rod cavity to continue filling the oil. If there is a large amount of oil leaking out of the pipe, it indicates that the hydraulic cylinder is leaking. You can also fill the bucket with loads, lift up to the limit, The big arm joystick is placed in the middle, and the engine is out of the fire, and the speed of the big arm is observed. Then the lever of the lever is placed in a higher position, and if the big arm sinks significantly faster, it also shows that the leak occurs in the hydraulic cylinder. If the rate of subsidence is not noticeable, the internal leakage is caused by the large arm slide valve.