Created on:2021-10-07 10:13

Hydraulic fault diagnosis and maintenance of hoisting and transportation equipment_ Hydraulic dump truck failure

Hydraulic fault diagnosis and maintenance of hoisting and transportation equipment_ Hydraulic dump truck failure

(1) Troubleshooting

① Causes and troubleshooting of slow lifting of the carriage: A. oil leakage at the oil pipe joint, replace the damaged gasket; b. If the sealing ring at the plunger, sleeve or cylinder head of the hydraulic cylinder is damaged, resulting in oil leakage, it shall be replaced with a new one; c. If the sealing ring in the distributor is damaged, replace it with a new one; d. If there are many impurities in the oil, the oil is too thick or too thin, the oil that meets the standard shall be added according to the season, and the oil with many impurities shall be filtered or replaced with new oil.

② Reasons why the carriage cannot be lifted and Troubleshooting: A. if the joystick is not placed in the "lifting" position, it should be placed in the "lifting" position; b. If the gear pump does not work, it shall be engaged if the power take-off is not engaged. If the drive output shaft is broken, it shall be replaced with a new part; c. The gear pump works but does not pump oil. If it is caused by insufficient oil in the oil tank, the oil shall be added to the specified oil level. If it is caused by the blockage of the filter or oil suction pipe, the filter screen shall be cleaned and the blockage shall be removed. If the oil viscosity is too high, the hydraulic oil of the recommended grade according to the season shall be used. If the sealing ring of the oil suction pan is missing or the sealing ring has been damaged, resulting in air leakage, a new sealing ring shall be installed, If the skeleton oil seal at the driving journal leaks, it shall be removed for inspection and replaced if necessary. If it is caused by serious wear on the gear surface of the gear pump, it shall be replaced with a new one; d. The sliding rod of the distribution valve is seriously worn and the pressure oil leaks from the slide valve rod. Replace the valve rod and re fit it; e. If the opening pressure of the safety valve is too small, and the spring fails or breaks, so that the oil forms a circuit, replace the spring and re commission the safety valve according to the specified pressure; f. If the oil is not clean and impurities jam the sliding rod of the distribution valve, filter the hydraulic oil or replace it with new oil.

③ Reasons why the carriage cannot return to the starting position and Troubleshooting: A. if the joystick is not in the "down" position, it should be in the "down" position; b. If the oil return pipe is blocked by sundries, remove the sundries.

④ Causes and troubleshooting of shaking when lifting the carriage: A. when air enters the oil circuit or hydraulic cylinder, tighten all joints and exhaust the air with the exhaust device; b. If the oil in the oil tank is insufficient, add hydraulic oil in time; c. If the hydraulic oil temperature is high, check the cause of high oil temperature and eliminate it; d. If the gear pump frame oil seal is damaged, replace it with a new one in time; e. There is dirt at the oil inlet of the distribution valve, and the amount of oil passing through is uneven. Check and clean the distribution valve.

⑤ Reasons why the carriage cannot be kept at the dump tilt position and Troubleshooting: a. the lifting oil circuit leaks, mostly because the joint is not tight or the seal is not tight. Tighten the joint and replace the damaged sealing ring; b. The distributor, slide valve core and sleeve are worn, and the matching clearance is too large, so they should be replaced with new parts; c. If the hydraulic cylinder leaks oil, find out the oil leakage and update the sealing ring accordingly.

(2) Key points for safe use

① Before driving, in addition to checking the engine, chassis and other parts, pay attention to check whether the hydraulic oil quantity and oil quality meet the requirements, and whether the connectors of the dump mechanism have defects such as cracks or deformation. If any, they shall be repaired or replaced in time.

② Start only after confirming that the carriage is flat, the valve of hydraulic dump hydraulic cylinder is closed and the safety is stuck, so as to prevent the valve from loosening due to vibration during driving and make the hydraulic cylinder lift automatically.

③ Choose a good road and don't drive too fast to prevent damage to the vehicle transmission system, walking system and hydraulic dump mechanism. When passing through obstacles, pay attention to prevent collision with the bottom of the axle.

④ Try to unload in flat areas. If it is necessary to unload on uneven sections or transverse ramps, try to pad up the low side tires and try to make the wheels on both sides horizontal, so as to prevent overloading on one side of the carriage due to the deviation of the center of gravity of the goods.

⑤ Carry out regular maintenance. The hydraulic system shall use hydraulic oil of specified brand, and vehicle oil shall not be used to replace hydraulic oil. Preheat before use in winter, but do not directly heat the hydraulic system with open fire.

⑥ When unloading, step on the accelerator slowly and release the clutch slowly. Otherwise, a large impact load will be generated in the hydraulic dump system, which will rupture or damage the oil pipe.

⑦ When unloading from a steep slope to a downhill, get off the vehicle first and observe it. The vehicle shall not be too close to the steep slope to prevent the rear wheels from sinking or the vehicle sliding down the slope during unloading.

⑧ Do not raise or lower the carriage during driving to prevent damage to parts due to vibration and swing of the carriage.

⑨ When it is necessary to lift the carriage for inspection and maintenance of the locomotive and hydraulic system, the safety brace shall be properly supported to prevent the carriage from falling suddenly due to the bursting of the oil pipe or the sudden failure of the hydraulic cylinder, resulting in mechanical and personal accidents.

⑩ When dumping the whole heavy object, due to the action of the reverse buffer device of the hydraulic dump system, it is easy to pull multiple hydraulic cylinders upward. In order to avoid this reverse pulling phenomenon, when the carriage is lifted to the appropriate position, reduce the throttle and reduce the lifting speed; When the whole weight is about to slide out of the carriage, immediately push the hydraulic control handle into the "neutral" position, stop lifting, and make the weight slide down by itself to ensure safety.

⑪ Overload operation is not allowed, otherwise the load of locomotive transmission system and hydraulic system will be increased and the locomotive will be damaged early.

⑫ After unloading, if it is difficult to lower the carriage due to the accumulation of goods or the goods cannot be unloaded completely, push the hydraulic control handle into the "neutral" position and move the vehicle forward. The vehicle shall not drive forward in the "raised" position to prevent reverse pulling. When moving the vehicle forward, pay attention to low altitude obstacles such as branches and wires.

⑬ Maintenance of hydraulic oil pipe: the hydraulic oil pipe shall be replaced every two years to prevent loss caused by aging. At the same time, regularly observe whether there is oil leakage at the fastening screw of the oil pipe. If oil leakage is found, it shall be eliminated in time.

Home    Article    Hydraulic fault diagnosis and maintenance of hoisting and transportation equipment_ Hydraulic dump truck failure