Several methods of fault diagnosis for hydraulic system of construction machinery      

After mastering the basic situation, we can use the exchange components, blocking branch oil circuit, logic reasoning exclusion methods for diagnosis.

(1) exchange element method. The faulty subsystems or suspicious components will be exchanged with the same subsystem to observe whether the failure phenomenon disappears or transfer, and if it disappears, the system or component is faulty. There are common cases:

A, double pump or multi pump system can exchange the output system of two pumps.

B, crawler motor can replace the tubing at the central rotary joint diagnosis, if a failover to the other side, then the fault point in the center of rotary joints and above position; if the fault phenomenon remains unchanged, is the center of the following parts of rotary joint.

C, the diagnostic center rotary joint sealing performance, can choose an oil inlet pipe, the outlet plug, open the other row of pipe joints, when to provide pressure oil inlet pipe, such as an exhaust pipe out of the oil, then they channeling between oil, seal damage.

D, with new components or the same element of the machine to replace suspected components for diagnosis.

(2) blocking branch oil way. Is a suspicious components or subsystems of temporary plugging, to observe the failure phenomenon disappeared to disappear for the system or component failure, the use of this method must comply with the principles of the blocked pipe should be to ensure that the system has sufficient unloading channel, which is to ensure the safety of system components.

(3) logic inference exclusion method. That is, according to the possible parts of the fault, the logic reasoning method is used for diagnosis and inspection until the abnormal phenomenon and the root of the fault are found.