Transmission Error Due to Resonance in Synchronous Belt Drive With Eccentric Pulley

Abstract

In synchronous belt drives, it is generally difficult to eliminate pulley eccentricity, because the pulley teeth and shaft hole are produced separately and the pulley is installed on an eccentric shaft. This eccentricity affects the accuracy of rotation transmission, so that the belt tension changes during a single rotation of the pulley. This in turn affects the occurrence of resonance in the spans. In the present study, the transmission error in a synchronous belt drive with an eccentric pulley in the absence of a transmitted load was experimentally investigated for the case in which the spans undergo first-mode transverse vibration due to resonance. The transmission error was found to have a component with a period equal to the span displacement, in addition to a component with a period of half the span displacement. During a single rotation of the pulley, the magnitude of the transmission error increased, and its frequency decreased, with decreasing belt tension. The transmission error exhibited the large value when two frequency conditions were satisfied: one was that the meshing frequency was within the range of span frequency variations due to the eccentricity, and the other was that the minimum span frequency was close to an integer multiple of the pulley rotation frequency. Even if both of these conditions occurred, if the range of span frequency variations due to the eccentricity was larger than 13 Hz, the transmission error could be eliminated by adjusting the belt tension, so that the average span frequency corresponded to the meshing frequency.

Transmission error in offset toothed double helical synchronous belt drives (in quasi-static condition)

“…Makita et al(2004) studied theoretically and experimentally the transmission error in synchronous belt drives with an idler, and results showed that the belt thickness errors between the belt pitch line and back face of the belt was a main reason of the transmission error generated. Kagotani et al(2017) studied the transmission error due to resonance between synchronous belt drive and eccentric pulley. Kagotani et al(2012) studied the transmission errors in which the belt spans generate first mode vibration due to the resonance, and results showed that the transmission error has a period of 1/2 of one pitch of the pulley.…”