Effect of polymer seal’s chemical and mechanical properties on automotive sealed chain’s transmission loss

ABSTRACT An automotive sealed chain consisting of an elastomeric seal between chain plates prevents the entry of external contaminants. But, the presence of a seal induces high transmission loss due to the frictional force. In the present study, a comparative transmission loss test between two ANSI-B29.1 520 series sealed chains of equal geometric dimensions (5/8” pitch) was carried out. The tests revealed a significant difference of 38% in their transmission losses between the chains. To understand these observed differences in the chain performance, the material analysis of the seals (nitrile butadiene rubber) was performed, which showed a significant difference in their composition. The increased seal hardness due to difference in chemical properties resulted in a 21% increase in friction coefficient between the seal and the plates. The seal thickness reduction, the effect of lubricant, and the difference in the frictional forces between chains yielded differences in the transmission losses. GRAPHICAL ABSTRACT