Bearing roller and/or closing rail for chain=drive construction machines

摘要

The bearing roller (3) and/or the closing rails are made of hard material. This material may be used for the whole part or only in those parts which are liable to abrasion during use. The hard-wearing region may be made of hard metal, fibrous material, ceramic-to-ceramic bonded material and/or engineering ceramic or high-duty ceramic, iron-based abrasion-resistant sintered material or a zirconium oxide, e.g. ZrO2, wholly or partly stabilised zirconium oxides, or on the basis of a non-oxide ceramic, e.g. silicon nitrite (Si3N4). The crack propagation in the material should be in the sub-critical region. The breaking viscosity should be not less than Klc = 5 MPa x sq. rt. of m.