Crawler unit, in particular for mini-excavator

摘要

To limit costs without compromising its life while at the same time simplifying its construction, the tracked running gear assembly (1) has its load-bearing wheels (4) and its track tensioning wheel (3) each comprising an idle roller (6) of austempered cast iron maintained on a shaft (7) of construction-type steel by two locking elements (8) of spheroidal graphite cast iron mounted as an interference fit on the ends of said shaft (7). The idle roller (6) comprises a lubricant chamber (9), the seal (19) being housed in the locking elements (8). The sprocket ring (26) of the drive wheel (2) is of austempered cast iron.