What is the working principle of excavator? If it cannot be started or it is difficult to start, how to repair it? How to repair if the work is weak? These problems will be described in this article, and the maintenance opinions are only for reference.
1. Working principle of distribution valve
The elastic plate of the torque converter is connected with the flying rotation of the engine, the elastic plate is connected with the cover wheel, and the cover wheel is connected with the transfer gear of the pump wheel. The rotation of the transfer gear drives the gear of the working pump shaft to rotate, and the hydraulic working pump starts to work.
2. It is difficult to start the excavator distribution valve if it cannot be started. How to repair it?
1) Key points of electrical system fault repair
If the battery power is insufficient, charge the battery in time, check the liquid level of the battery, and supplement the electrolyte to the specified height in time. If the battery is found to be aging and poorly charged. You should replace the battery and pay attention to the daily maintenance of the battery. Don't let the battery often be in the state of power loss.
2) Key points for maintenance of engine oil circuit fault:
Low pressure oil circuit air resistance: under the suction action of the oil transfer pump or fuel injection pump, the fuel is sent from the fuel tank to the high-pressure pump through the low-pressure oil circuit. If the low-pressure oil circuit is not tightly closed, or the oil level in the oil tank is too low, and the vehicle is parked and driven obliquely, the air will take the opportunity to enter the oil circuit; If the temperature is high and the fuel evaporates, air resistance will also be formed in the low-pressure oil circuit, resulting in unstable engine operation, automatic fire or engine failure to start.
Oil circuit blockage: the common parts of oil circuit blockage mainly include oil suction pipe, filter screen, diesel filter, oil tank cover vent, etc. The main problem of oil circuit blockage is the injection of substandard diesel oil or the mixing of impurities in the refueling process. The key to prevention is to ensure that the purple oil is clean and the oil circuit is sealed, maintain the oil circuit regularly, strengthen the cleaning and maintenance of the diesel filter, clean or replace the core in time, clean the oil tank in time according to the operating environmental conditions, and completely remove the oil sludge and moisture at the bottom of the oil tank.
Failure of fuel injection pump: the plunger and outlet valve parts of fuel injection pump are seriously worn, resulting in difficulty in starting the engine. At this time, the plunger and oil outlet valve parts shall be replaced in time.
3. How to repair the excavator distribution valve when it is unable to work?
1) The engine has sufficient power and operates normally. The distribution valve of the excavator operates slowly and the excavation is weak
2) Most of the hydraulic pumps of the distribution valve of the excavator are variable piston pumps. After working for a certain time, the internal parts of the pump are inevitably worn, resulting in internal leakage, and the parameter data are inconsistent, resulting in insufficient flow, high oil temperature, slow speed and unable to establish high pressure, so the action is slow and weak. For such problems, it is necessary to remove the hydraulic pump for data measurement, confirm the problem, replace the parts that can not be used anymore, or repair the parts that can be used again, conduct bench commissioning after reassembly, and match the parameters of each circuit (pressure, flow, power, variable, etc.).
3) An important hydraulic component on the excavator distribution valve – multi-channel distribution valve, which has main safety valve, secondary valve, overflow valve, oil makeup valve, etc. If the pressure set by these valves does not reach the standard pressure, the excavator will operate slowly and powerless.
The above is about the failure cause analysis and maintenance points of excavator distribution valve that cannot be started or is difficult to start and unable to work. When the excavator hydraulic system fails, check around the hydraulic pump, distribution valve and oil cylinder. The specific judgment of where the fault occurs should be based on the actual situation. Check the small part first. Generally, check the safety valve on the distribution valve first. This safety valve often gets stuck. When overhauling the distribution valve, be sure to pay attention to safety, and the boom must be flat on the ground.
