摘要 |
<p>In the case that a lubricant is impregnated in bushings, during the operation of an oil-free chain, the lubricant satisfactorily flows out from the pores of the bushings, oil film breakage at the sliding portions of the bushings is suppressed from occurring, the oil film strength is high, and the oil-free chain has a sufficiently long abrasion elongation-resistant life . An oil-free chain is constructed by alternately connecting a pair of outer link plates connected using pins and a pair of inner link plates connected using oil-impregnated bushings into which the adjacent pins of the outer link plates adjacent to the inner link plates are fitted. The oil-impregnated bushings are impregnated with a lubricant having a kinematic viscosity in the range of ISO-VG grade 46 to 460, the weight % of an ingredient having the highest content among the elution ingredients obtained by the GPC method is 95 wt% or more, the number average molecular weight is 800 or more and 2300 or less, and the ratio of the weight average molecular weight to the above-mentioned number average molecular weight is 1.0 or more and 1.3 or less.</p> |