The small roller is suitable for the construction needs of some construction sites. After being used for a period of time, the small roller appears the phenomenon that the machine can't move or can't move forward and backward when it is engaged and pressed on the accelerator. In order not to delay the repair time and affect the construction site, the roller shall be repaired as soon as possible to make the roller return to normal quickly. The construction personnel shall master the fault causes and troubleshooting methods.

Small hand roller

1、 Fault causes of small roller not running in gear

1. If the oil seal of the output shaft of the torque converter leaks oil, the damage of the oil seal should be considered, but the specific cause of the fault can be confirmed only after troubleshooting. In case of failure to move in gear, the transmission shall be checked.

2. Start the diesel engine and observe and confirm that the oil seal of the output shaft of the torque converter leaks oil. Remove the torque converter output shaft and flange, remove the oil seal and find that it has been deformed. After replacing the new oil seal, start the diesel engine. A few minutes later, the oil leakage of the torque converter output shaft oil seal occurs again, which indicates that the fault position is not found.

3. After removing the oil seal, it is found that the oil seal is deformed again, so it is determined that there is high oil pressure at the oil seal, which may be related to poor oil return.

4. Remove the torque converter and check that it is not improperly assembled. However, when cleaning the guide wheel shaft, it was found that there was foreign matter in the oil hole. After picking it out with a needle, it was found that it was a section of black colloid.

5. The sealing quality of crude oil is poor. After a period of use, it deforms and leaks oil, and the operator will replace it by himself. In case of oil leakage during replacement, a layer of sealant was applied. However, when applying the sealant, the sealant was accidentally squeezed into the oil passage, making the oil circuit blocked, resulting in higher and higher oil pressure at the output shaft of the torque converter, resulting in deformation and oil leakage of the oil seal.

6. Whether the connection between the control device and the manual service valve of the main pump is loose, and whether the emergency stop button is in the emergency stop position; The emergency stop solenoid valve Y7 fails, so that the directional valve changing the pump displacement is directly connected, and the system output is 0; The driving reducer or rear axle brake is "locked".

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7. The reason why the reversing valve cannot reverse may be that the reversing valve does not reverse, and the failure of the reversing high-pressure overflow valve causes the unloading of the traveling drive pump.

8. First measure the driving pressure, the pressure is basically 0, and the oil make-up pressure and object pressure are normal (if the driving Lele exceeds 40MPa, it may be that the driving wave speed machine or the rear axle brake is "locked", and judge that the trouble relief may be in the hydraulic system. After analyzing the causes of the faults, then carry out troubleshooting for these causes.

2、 Troubleshooting of small roller not running in gear

1. After replacing the oil return pump and new oil seal, the oil seal leaked again for 10min, so it was suspected that there was a problem in the assembly of the torque converter.

2. Remove the sealant residue in the oil passage, carefully check all parts of the torque converter and reinstall the torque converter. After 1h test run, the fault phenomenon disappears.

3. Check the case stop pull-out button in the cab, and the pull-out button is in the driving state. Then check the connection between the driving joystick and the manual servo valve of the main system, and it is normal. Check the tight power failure contact, and use a small electrician screwdriver to approach the energized electromagnetic network. It is found that there is no suction, and the resistance value of our park is not too large. It is judged that the electromagnetic money is open. After replacing the electromagnetic wire, the machine still can not walk. Open the line It is found that there is no pressure oil output from the traveling drive at port X or x2 on the traveling drive system, and there is a jamming in the inner core of the power-off grid when it is tightened by hand. It can be eliminated after clearing the tight stop electromagnetic idle.

4. First, check the system pressure during backward. The measured oil replenishment pressure is 2.5MPa, the low gear of forward driving pressure is about l3mipa, the high gear is about 26mpa, and the backward driving pressure is almost O. directly push the valve core of Hefu valve by hand, and the valve core can slide freely.

5. When the backward high-pressure overflow valve fails, the backward and forward high-pressure overflow networks are exchanged. At this time, there is no response in advance, and then the backward is normal. Therefore, it is judged that the backward high-pressure overflow valve is faulty. After checking that the valve core, valve seat and spring yellow are normal, it is determined that the pressure regulating nut of the pilot valve of the high-pressure overflow valve is loose. Tighten the pressure regulating nut to make the setting value of the overflow valve meet the specified value Then try the machine again, and the driving can return to normal.