In small-scale excavation opportunities, the entire vehicle does not move. Have you ever wondered what caused this?
Small excavators regularly maintain vehicle cleaning, component inspection and lubrication, and replacement and repair of damaged components, mainly for the effective use of excavators and good technical conditions to avoid component loss. The resulting failure provides a good guarantee for people's safety. Gears play an important role in the overall structure of the excavator. Once the surface of the excavator gear is damaged, maintenance personnel must repair the gear at this time. Several maintenance systems of small excavators specifically describe the hydraulic system of the excavator. The structure and working principle of pumps, valves, motors, hydraulic cylinders and auxiliary components in the hydraulic system are introduced in detail. Describes the disassembly, maintenance and installation methods of each component in detail.
In each model, the electronic control system and methods of fault diagnosis and troubleshooting are also introduced systematically.
Explain the symptoms:
The whole car did not move when the machine was working. What's the problem? How can it be solved? The excavator repair shop explained the failure analysis process to the owner:
Generally, when the whole vehicle fails without action, the following aspects can be checked. Of course, specific issues require specific analysis. The following content is for maintenance reference:
1. Check whether the solenoid valve is dirty or damaged, and replace the solenoid valve;
2. There is also a safety solenoid valve. Check that there is no problem. If damaged, replace the safety solenoid valve;
3. The coupling may be damaged and needs to be replaced;
4. Whether there are circuit contacts that cause the vehicle to be invalid, repair the circuit for inspection;
5. Check whether the hydraulic lock is damaged, and replace the damaged hydraulic lock;
6. At the same time, check whether the pilot oil circuit is blocked by foreign matter, and clean and drain the blocked oil circuit;
The common causes of crankshaft failure of small excavator diesel engine are as follows.
First, when the lubrication is not good.
In the diesel engine lubrication failure system, the semi-friction connection between the journal and the gasket, that is, the weakening of the cutting part of the bearing force will cause the bearing to burn and fail, the shaft will run frequently, and the pressure will change after the root is removed. This causes a break between the root of the crankshaft and the crank arm.
Secondly, the bearing is not working well.
For diesel engines, when the main bearing is rolled by the rolling pivot, or when the clearance is too large and the main bearing has different shafts, it is too large, that is, frequent crankshaft, flywheel and radial deflection. The diesel engine itself has specific gravity and crankshaft. Uneven force, plus the influence of the operation of each cylinder. In addition, when the gap of the connecting rod bearing assembly is too large, or the alloy falls, the impact load will cause the crankshaft to break for the first time, resulting in an increase in the cause of fracture.
Third, the loosening of the main bearing cap nut is one of the important reasons for the early fatigue fracture of the crankshaft, because the crankshaft is lost or loose in the bracket, or each coaxial bearing hole is coaxially offset.
If the loose main bearing nut makes the track shaft loose and the bearing clearance affects the passage, the diesel engine must exceed the tolerance, which is the loss of the main journal. If the concentricity deviation causes the crankshaft to rotate to the end of the hole of the cause case, the crankshaft load of the crankshaft is different, which may cause a crankshaft fracture accident. Don't be nervous when the small excavator is not moving, find out the reason first, then solve it, and look for it according to the method explained above.