Control components include various valves, such as pilot valves, multi way directional valves, main safety valves, relief valves, and one-way throttle valves. Although the functions of various valves vary greatly, their common faults are similar, mainly including card sticking, loose closing, weakened spring elasticity, and internal and external leakage.

 

Auxiliary components mainly include fuel tank, oil pipe, radiator, filter, and accumulator. The function of a radiator is to dissipate the heat generated by the hydraulic system to the atmosphere. Common faults include oil leakage and poor heat dissipation. The function of a filter is to filter out impurities mixed into hydraulic oil, and common faults include clogged filter screens. The function of an accumulator is to stabilize the control of oil pressure and store a certain amount of energy to ensure smooth operation. When the engine fails and cannot work, it can lower the working device to the ground. Common faults include poor energy storage effect and inability to complete the above functions. The fault phenomenon of auxiliary components is generally more obvious and easy to diagnose.

 

The power components are mostly variable displacement piston pumps, whose function is to convert the mechanical energy of the engine into the pressure energy of the liquid. The common fault phenomenon is insufficient pump oil pressure and reduced flow rate. If this phenomenon is gradual and becomes more pronounced as the temperature increases, it is caused by excessive wear of the hydraulic pump; If this phenomenon is sudden, it is mostly caused by a plunger not working; If the pressure is normal and the flow suddenly decreases, it is usually caused by the variable mechanism getting stuck in the low flow position.

 

The executing components include hydraulic cylinders and hydraulic motors, whose function is to convert the pressure energy of liquid into mechanical energy. Common fault phenomena are slow or no action. If it is confirmed that there are no faults in the pump and valve, the reason for the slow action of the actuator must be due to excessive wear and tear; If the pump is working normally and one of the actuating elements is moving slowly, it is likely that the valve controlling the actuating element is faulty, such as the valve not being in place, the overflow valve not closing tightly, or the spring elasticity weakening or jamming. Due to the fact that the wear and tear of each executing component does not differ significantly, if it is caused by other reasons, it should be due to the sudden slowing down of the actions of multiple executing components at the same time; If it is known that both the pump and valve have no faults, and a certain actuator suddenly fails to operate, it is mostly due to its internal jamming.