Abstract:
Arm-type tensioner is widely used in the automotive engine belt system, whose spindle often break during actual working process caused by fatigue. It is necessary to study the mechanics properties of the tensioner and try to find a method for calculating the spindle’s fatigue life. In this paper, taking the arm-type tensioner in automotive engine as a research object, the mechanics analysis is carried out for the tensioner in working process. The mechanics model for calculating the forces and the method for calculating the bending stress of the tensioner’s spindle are established. The fatigue life of the tensioner’s spindle is calculated by using the fatigue theory and rain-flow counting method. With a specific example, the fatigue life of the tensioner’s spindle is calculated numerically and verified by comparing with the actual life of spindle. Several parameters’ influences on the mechanics performance and fatigue life of the tensioner’s spindle are studied. It is found that the main factors affecting the fatigue life of the tensioner’s spindle are the distance between pulley and rotating arm (
l1), and the bushing length (
l2), decreasing
l1 and
l2 can effectively increase the fatigue life of the spindle, while the length of the arm (
L) and the vortex spring torsion stiffness (
T') have no significant effects on the fatigue life of the tensioner’s spindle.