1. There is high temperature in the hydraulic system, and the piston rod frequently contacts the low temperature environment in the high temperature state (especially in cold season) when working (sudden drop of temperature).
2. During the maintenance period, the special hydraulic oil for excavators other than this brand was replaced. Generally, the piston rod will change color within a few days after oil change. The reason is that there is an extreme pressure and anti-wear additive in hydraulic oil with different quality and performance.
3. The uneven temperature control in the process of piston rod electroplating leads to cracks on the surface of electroplating layer in the later work. Observing the surface of the piston rod with a high magnification magnifying glass, you can see irregular small cracks.
Extended data:
The traveling device, namely the chassis, comprises a crawler frame and a traveling system, and the traveling system mainly consists of the crawler frame, a traveling motor+reducer and its pipeline, a driving wheel, a guide wheel, a supporting sprocket, rollers, a crawler and a tensioning buffer device. Its function is to support the weight of the excavator and convert the power transmitted by the driving wheel into traction, so as to realize the walking of the whole machine.
Form of shovel action of front shovel excavator. Its characteristic is "advance, forcibly cut the soil". The front shovel has great digging force, which can dig out the soil above the parking surface. It is suitable for digging dry foundation pits with a height greater than 2m, but it must be equipped with an up-and-down ramp. The bucket of the front shovel is larger than that of the equivalent backhoe excavator, and the digging water content is not more than 27%.
For three kinds of soil, the whole excavation and transportation operation can be completed with dump trucks, and large dry foundation pits and mounds can also be dug. According to the different relative positions between the excavation route and the transport vehicle, there are two ways to excavate and unload the soil: front excavation and side unloading; Forward excavation and reverse unloading.
Baidu encyclopedia-excavator