How to solve the hydraulic oil temperature anomaly of the pump car   

During the working process of a pump truck, the phenomenon of abnormal increase of hydraulic oil temperature rises. The oil temperature rises to 70 degrees at 0.5h, when the cooling fan turns and stops, there is no continuous work.

Sharp tools make good work。 We first come to know the basic principle of the hydraulic oil temperature control of the pump car:

The temperature sensor detects the temperature of the hydraulic oil in the signal is converted to an electrical signal transmission to the PLC controller (SYMC controller), PLC control solenoid valve coil power, coil power driven spool movement, thereby changing the hydraulic pump output pressure size, high pressure oil to drive the hydraulic motor to rotate, the motor drives the rotation of the fan, reduce the oil temperature. The normal use of the hydraulic oil temperature is between 20 to 70 DEG C, cooling fan began to work in the oil temperature of about 40 DEG C.

Cause analysis:

Pump abnormal temperature and cooling system has a direct relationship, the fan dynamic stopped the oil temperature is too high, a common cause of air cooling system does not work as follows: cooling fan motor mechanical fault; the temperature sensor failure; the PLC control module has no output signal; the cooling fan solenoid valve failure; the connection of electrical components not strong.

Troubleshooting:

First of all, it is to check the internal leakage of the air-cooled motor, rotate the motor blades with the hand, find the rotation smoothly and flexibly, disassemble the drain pipe of the motor, observe the leakage of hydraulic oil, and find that the leakage is small, which indicates that the air-cooled motor works normally. If the leakage is large, the motor is damaged.

Then check the electrical circuit, the electrical connection found strong, loose, and then connect the power and start the engine, the PLC controller has observed temperature data show that it can determine the oil temperature sensor, circuit connection and PLC controller circuit components and no fault.

When associated with the cooling system of air-cooled electromagnetic valve has not only check, check the air solenoid valve again after turning on the power switch resistance of the multimeter is used to measure the electromagnetic valve coil, and the voltage applied to the coils, the measured resistance value is 26 ohms, voltage is 27V, which belongs to the normal range. But when a voltage is applied with a micro spool sound, the spool moves not free, that may be the spool card, remove the solenoid valve spool, the spool rod found deformation, thus fan dynamic stopped phenomenon, the replacement of a solenoid valve, solenoid valve again to the load voltage, the fan rotation is normal, troubleshooting.

After troubleshooting, we must know the working principle of the fault location first, then look for the cause of the possible failure, and investigate it one by one.