Identification of V-belt power losses with temperature measurement

The efficiency of V-belt drives is determined by several factors collectively: the slip occurring during drive transmission, the external friction occurring when the belt enters and exits the pulley as well as the hysteresis loss resulting from inner friction. An experimental apparatus and calculation method was developed in order to determine the increase in temperature emerging from the contact of the belt and the pulley in idling mode. The tested V-belt piece was bent on a pulley performing alternating motion while the temperature of the V-belt was measured. During the testing the temperature generated in the V-belt was measured as a function of changes in three parameters (Pretension, diameter of pulley and bending frequency). On the one hand, the temperature generated in the V-belt can be estimated with the assistance of the function determined on the basis of the testing results. On the other hand the so-called damping factor characterizing the contact with the pulley (The external friction when entering and exiting the groove) and the hysteresis loss (Inner friction) are also determined. On the basis of the damping factor (ξ≈400 Ns/m2) of the V-belt involved in the experiments the other losses (Poth) occurring from the pulley-V-belt contact and internal friction may be estimated. With the help of the mathematical models defined for the pulley diameter and belt frequency, taking into consideration the minimization of heat generation, optimal parameters can be calculated that serve as beneficial references for designing and tuning V-belt drives.