Construction machinery_ Construction and construction machinery_ Sudden failure of vibratory roller

Construction machinery_ Construction and construction machinery_ Sudden failure of vibratory roller

Yzjl2 vibratory roller is driven by F6L912G air-cooled diesel engine through the transfer case to operate one and the other at the same time, providing power sources for travel drive, vibration excitation motor and steering cylinder respectively. The hydraulic system is shown in Figure t.

During the operation of the machine, the symptoms of unable to walk and no vibration suddenly appear, but the steering is normal.

Since the steering of the roller is normal, the fault in the transfer case can be eliminated, so that the fault point can be concentrated on the hydraulic system. According to the hydraulic system diagram of the machine, the fault range is reduced step by step according to the following steps, so as to eliminate the fault.

① Remove an oil pipe from the vibration hydraulic motor 9, start the diesel engine and turn on the vibration switch. There is no oil from this pipe, indicating that the motor is normal; Remove the oil outlet pipe of the vibration steering (duplex) gear pump 14 and start the diesel engine. The pressure oil (and the pressure is very high) flows out of the gear pump, indicating that the duplex gear pump works normally, indicating that the fault of the vibration system should be in its control system.

② The control system of the vibration part is controlled by the solenoid valve and the pilot valve at the same time, and the control oil is supplied by the compensation pump on the variable displacement pump. At the moment of opening the vibration switch, the solenoid valve has a "click" sound, indicating that the solenoid valve is normal; Remove the hydraulic pipe from the compensation pump to the solenoid valve and start the diesel engine. There is no hydraulic oil at the outlet of the hydraulic pipe, indicating that the compensation pump is not working normally.

③ Remove a hydraulic oil pipe from variable displacement piston pump 15 to the drive motor and start the diesel engine. No pressure oil flows out of this oil pipe, indicating that the variable displacement piston pump is not working normally. According to the hydraulic system diagram, the variable piston pump is supplied by the compensation pump on it, so the fault is likely to be on the compensation pump. Therefore, the compensation pump was removed and disassembled. After cleaning, it was carefully inspected. It was found that the semicircular key connected between the driving gear and the driving shaft of the pump had been broken, and the gear and the shaft could rotate relative to each other, indicating that the compensation pump could not work. After replacing a semicircular key, the whole machine will return to normal.