In the engineering design attempt to minimize customer complaints related to belt misalignment, a maximum belt pulley entry and pulley exit angle was chosen as a critical target for avoiding excessive belt wear and chirp noise.
Calculating belt misalignment due to pulley misalignment from the perfect plane between two grooved pulleys is done using statistical stackup calculations in three dimensional space. This is usually done using available computer statistical simulation models and the most current component detail drawings.
For backside pulleys (flat pulleys), such calculations can be performed only if the position of the belt as it contacts a backside pulley is known. Since the shape of the grooves no longer fixes the position of a belt at pulley entry
point, the position of the belt at the backside pulley can not be determined by the position of the pulley groove. The most challenging part of this analysis, and the focus of this paper, is how to determine the belt angles that result from non-perfect backside pulley locations and angles.
In order to better understand this effect, a series of toe/camber experiment were initiated by Ford Motor Company and Dayco Corporation outlined in this report.