3109 Influence of Resonance on Transmission Error in Synchronous Belt Drives Under Installation Tension

Synchronous belt drives generate resonance on the belt spanning between the driving and driven pulleys when the transverse natural frequency of the belt approaches the meshing frequency of the pulley and belt teeth. This resonance affects the accuracy of the rotation transmission device installed in the drive system. In a previous report, it was found that the transmission error caused by first mode vibration due to resonance in synchronous belt drives was generated with a period of 1/2 of the pitch of the pulley. However, transmission errors are also generated with a period of one pitch of the pulley, a case which has not yet been examined. In the present study, a transmission error comprising both periods of one pitch and 1/2 of the pitch of the pulley in a synchronous belt drive was experimentally investigated for the case in which the belt at the span generates first mode vibration due to resonance. The installation tension was varied while the rotation speed of the pulleys was fixed, maintaining a speed ratio between the pulleys of 1:1. Analyses of the transmission error based on the experimental results were carried out, and the calculated results of the transmission error were compared with the experimental results. The agreement obtained confirmed the validity of the analyses. It was found that the transmission error of a period of one pitch of the pulley was generated by the difference in belt length between the upper and lower spans due to the resonance.