The phenomenon of engine oil blackening is a cliché, but the blackening of hydraulic oil seems to have not been specifically mentioned. Today, the editor of the concrete mixing pump will explain to you several reasons for the blackening of the hydraulic oil of the concrete mixer with pump the mixing trailer pump:
A. The influence of metal impurities
1. It may be the wear debris generated by the high-speed rotation of the pump. You must consider all the parts that rotate with the pump, such as the wear of the bearing, the volume chamber, etc.;
2. The hydraulic valve spool runs back and forth, and the wear debris generated by the back and forth operation of the cylinder, but this phenomenon will not occur in a short time;
3. Concrete mixing pump is a new machine, which will produce a lot of iron filings when the equipment is running in. I don’t know if you have completely emptied the hydraulic oil in the oil tank when changing the oil, and after using the new oil circulation system, wipe the oil tank clean with cotton cloth. Add new oil. If not, there may be a large amount of iron filings left in the oil tank, which will also cause the new oil to be contaminated and blackened.
B. External environmental impact
Check whether your hydraulic system is closed and whether the breathing hole is intact; check the exposed parts of the hydraulic part of the equipment to see whether the seal is intact, such as the dust ring of the oil cylinder.
1. The hydraulic oil was not cleaned when changing;
2. The oil seal is aging;
3. The poor working environment of the excavator causes the filter element to be blocked;
4. There are a lot of bubbles in the air inlet of the hydraulic pump;
5. The hydraulic oil tank is connected to the air. Dust and impurities in the air will enter the oil tank after a long time, and the oil must be dirty;
6. If the particle size test of the oil meets the cleanliness requirements, it can be ruled out as dust pollution. It can be said with certainty that it is caused by the high temperature of the hydraulic oil! At this time, you should switch to high-quality hydraulic oil, check the oil return filter element, the heat dissipation oil circuit, and the focus is on the hydraulic oil radiator. It should be maintained in accordance with the regulations.