Diagnosis of weak movement and vibration loss faults of vibratory rollers

When troubleshooting, we follow the principle of "starting with the easy and moving on to the difficult" to conduct the following checks: First, check for faults other than those in the hydraulic system, including whether the engine power is sufficient and whether the rotational speed is adequate; Whether the manual control mechanism is loose, stuck or does not travel properly; Whether the voltage and current are normal. Second, check the oil quantity and quality in the hydraulic oil tank, and whether the oil filter is dirty, etc. After eliminating the above factors, diagnosis should be made based on different faults.

1? Diagnosis of weakness in walking

(1) Check whether there are mechanical faults in the connection components between the engine and the hydraulic pump, as well as between the hydraulic motor and the drive wheels. Check whether the bypass valve installed on the front drive motor is in the open state. If so, the high and low pressure oil chambers will be connected.

(2) Check the braking system. When the engine is operating normally and the solenoid valve is energized, check whether the brake can be disengaged. If it cannot be disengaged, check for mechanical faults. If not, you can use the dragging method to release the brake (turn the manual pump handle counterclockwise), and then proceed with the following checks.

(3) Check the high-pressure pressure and oil replenishment pressure of the main circuit of the walking hydraulic system. Connect a 60MPa oil pressure gauge to each of the two high-pressure pressure measurement ports, and a 4MPa oil pressure gauge to the oil replenishment pressure measurement port, and then conduct a test run. At normal temperatures (30 to 60℃), the oil replenishment pressure is approximately 2? The pressure should be no less than 2 mpa when the machine is moving. 4MPa; When encountering resistance during walking, the maximum pressure of the main circuit can reach 38MPa, and it is not less than 20MPa during normal walking. If both are normal, it indicates that the fault lies in the mechanical aspect.

If the oil replenishment pressure is lower than the specified value, place the walking control lever in the middle position to adjust the overflow valve of the oil replenishment pump (Note: Observe the oil replenishment pressure gauge during adjustment. The adjustment range should not be too large and remember the original position). If the pressure cannot reach the normal value or the pressure gauge reading remains unchanged, it can be determined that there is a fault with the overflow valve or the oil replenishment pump. If the oil replenishment pressure is normal when the machine is not running, but drops significantly during the walking operation, the back pressure of the return oil pipe on the walking motor should be measured. This pressure should not be less than 2MPa. If the pressure is low, it indicates that there is a fault with the shuttle valve and the low-pressure relief valve of the motor. When the oil replenishment pressure is higher than the specified value, the pressure of the relief valve can be reduced. If it cannot be reduced, it indicates that there is a fault with the relief valve.

If the high-pressure pressure is low, the fault may be caused by the hydraulic pump, hydraulic motor, or multi-functional valve block (including the high-pressure relief valve). The two main pipes of the pump can be removed, and the outlet of the pump can be blocked with a plug. Let the engine idle and slowly push the walking rod forward and backward at a small Angle. If the pressure is abnormal, the multi-functional valve block should be disassembled and inspected. If the multi-functional valve is normal, it is caused by internal leakage of the hydraulic pump. If the high pressure is normal, it indicates that there is a problem with the motor. How to determine which motor is faulty or both motors are faulty? The inlet and return oil pipes of the front and rear motors can be removed respectively. After blocking them with plugs and testing the machine, the motor with abnormal pressure is the faulty motor. It can also be determined by measuring the oil leakage of the motor. The method is to disassemble the oil leakage pipe of the motor and connect a measuring cylinder. A leakage of 3 to 4L/min under normal pressure is normal; otherwise, it indicates that there is a fault with the motor.

If the high pressure is too high, it indicates that there is a fault with the high-pressure relief valve.