Dual dynamic absorber for the torsional vibrations of synchronous motor-driven compressors

This paper presents a dynamic absorber to reduce the torsional vibrations exhibited during start-up of systems driven by synchronous motors. The dynamic absorber is comprised of two inertia rings connected, via spring-like material, to both the driver side (motor) and the driven side (compressor). The stiffness and inertia properties of the absorber are optimally tuned to match the torsional natural frequency of the system. A lumping technique is used to produce the dynamic model with non-linear flexible coupling. The results of the basic model are verified by using the results of previously published work on the modelling of non-linear flexible couplings. The numerical results on the dual dynamic absorber show excellent reduction in the vibration amplitudes as well as noticeable reduction in the vibration duration. Furthermore, the results of this study indicate that this kind of dynamic vibration absorber will contribute to solving, practically, the problem of torsional vibrations in systems driven by synchronous motors. (C) 1999 Academic Press.