From transmission error measurement to pulley–belt slip determination in serpentine belt drives: Influence of tensioner and belt characteristics

Serpentine belt drives are often used in front end accessory drive of automotive engine. The accessories resistant torques are getting higher within new technological innovations as stater-alternator, and belt transmissions are always asked for higher capacity. Two kind of tensioners are used to maintain minimum tension that insure power transmission and minimize slip: dry friction or hydraulic tensioners. An experimental device and a specific transmission error measurement method have been used to evaluate the performances of a generic transmission by determining the pulley–belt slip for these two kinds of tensioner. Transmission error between pulleys, pulley/belt slip are deduced from pulley rotation angle measurements. Results obtained show that: the use of tensioner limits belt slip on pulleys, pulley–belt slip is reachable from transmission error measurement, belt non uniform characteristics are responsible of low frequency modulations of transmission error.