Contrary to appearances, the steel elements of the running gear in construction machines are very easy to wear, although they seem extremely solid. Excavator track rollers are made of a suitable boron-steel alloy and centrally or induction hardened. This is to protect them from wear of several millimeters and extend their service life. Once the coating wears off, the rollers deteriorate faster. This is clearly visible when you place a new and worn roller next to you. The difference is noticeable to the naked eye.
Lower rollers carry most of the excavator’s weight via the tracks to the ground. The upper rollers, on the other hand, are designed to lead the chain in a straight line. When the rollers are wearing out, replace all of them on the same side of the machine at the same time. Otherwise, there is a risk of premature failure of the track and other undercarriage components. This is because said track roller is slightly larger in diameter than the worn roller and will place an excessive load on both the rollers and the track. Working on rollers with varying degrees of wear may also cause reduced productivity of other undercarriage parts in the excavator, or even their failure.
Signs of failure of the rollers
Roller wear is caused by the pressure of two elements against each other in the presence of relative motion. As a result, small particles crumble from the surface of both of these elements. Additionally, this process can be intensified by any contamination in the chassis. The photo opposite perfectly illustrates the areas where the rollers tend to wear out.
How else can you tell if the excavator track rollers are damaged? Including after oil leakage from the roller (in the case of damaged seal), grinding sounds or increased resistance. The rollers can also be less stable and move “side to side” when turning. In addition, the increased pressure in the hydraulic system may also be noticeable. This is because the energy needed to drive the tracks then increases. Therefore, overloads will also occur on other elements, e.g. drive sprocket or sleeves protecting the pins of the chain.
Can I prevent wear of the rollers? Yes of course! Regular maintenance and cleaning is a must to ensure the longest life of the rollers and other components.