How to solve the rotation failure of scraper motor of paver?
In the actual test of 1 new paver, the use side found that after the paver operation 260h, the scraper can not stop phenomenon. Even if the main console switch is closed, the scraper hydraulic system solenoid plug is removed, and the scraper motor can still rotate.
1. composition and working principle
It is understood that this type of paver scraper system adopts the new structure and layout, which is mainly composed of hydraulic fuel tank, scraper pump, electromagnetic relief valve group, scraper motor, hydraulic oil filter, etc., as shown in figure. The scraper pump adopts the P R R-022/022L gear pump, and the scraper motor model is OMTS315. The electromagnetic relief valve group model is 98301113DWG/03, which consists of 2 normally open type plug-in overflow valve and 1 two bit two way solenoid valve, in which the plug-in overflow valve model is SV4-8-O-0-24DGS. 2 plug-in relief valves are used to control the left and right scrapers respectively. When the electromagnet Y26 is not power, the hydraulic pump pump the pressure oil back to the hydraulic tank; when the electromagnet Y26 gets the electricity, the oil pressure is returned to the tank, and the scraper motor works.
2. troubleshooting
Check the electrical system and find no abnormalities. Check the hydraulic oil is clear and pollution-free, the hydraulic oil temperature is within the normal range. Check hydraulic oil pipeline unobstructed, hydraulic oil radiator work properly. Disassembly examination electromagnetic overflow valve group, found that its spool is normal, no impurities, spring pressure is normal, spool switch flexible. The replacement of the new electromagnetic overflow valve assembly on the spot, the failure has not yet been ruled out, thereby eliminating the possibility of electromagnetic overflow valve group failure.
Communication with the use of the party, that the new machine used when normal, work 260h only appear scraper rotation failure. In the early stage, only one side of the scraper motor rotates, and when the hopper is very small, it will rotate, and then gradually develop into two sides scraper, the motor will rotate, and more materials will rotate. Therefore, when the electromagnet Y26 gets electricity, partial pressure oil can still be returned to the oil tank by the motor, causing the motor to rotate.
For further verification, connect the pressure gauge at the intake port of the scraper motor and test the pressure 0.4MPa, indicating that there is indeed some pressure oil flowing through the scraper motor. After consulting the technical department for approval, 1 test machines for one-way valves with 0.5MPa opening pressure are installed on the oil outlet pipe of the scraper motor, and the paver failure is eliminated. Through the near 800H assessment test, the fault did not occur again.
3. cause analysis of trouble
The analysis shows that when the electromagnet Y26 is out of power, the pressure oil from the scraper pump should all flow back to the hydraulic tank through the electromagnetic overflow valve set. The opening of the electromagnetic relief valve matches the displacement of the scraper pump. It may be that the opening of the solenoid relief valve is too small, and the residual oil pressure is passed through the scraper motor when the electromagnet Y26 is powered off.
When the new equipment is used in the early stage, the mechanical transmission parts of the scraper system of the paver are new, and they are in the running in period. The mechanical resistance is great, and the residual oil pressure can not drive the scraper motor to run. With the extension of the use time, the scraper driving device keeps running in and the mechanical resistance gradually decreases and tends to be stable. When the mechanical resistance of the scraper system is reduced to a certain extent, the scraper motor begins to rotate. The above analysis, and the actual work in less than the beginning of rotation, and then more data will also be consistent with the rotation.
A one-way valve with an opening pressure is added to the oil outlet port of the scraper motor to eliminate the influence of the residual oil pressure on the motor so as to eliminate the trouble.
