On the Dynamic Balancing of a Planetary Moving Rotor using a Passive Pendulum-type Device

The possibility of using self-balancing devices to reduce the vibration amplitudes in planetary moving rotors is investigated analytically using the averaging method for a partially strongly damped system. Self-balancing was shown to be effective for a planetary moving rotor in the overcritical speed domain. However, the centrifugal forces caused small vibrations of the pendulum balancers, which increased with the increase of the velocity of the planetary motion. The analytic results match the numeric simulations very well as long as the velocity of the planetary motion is sufficiently small. To avoid high amplitudes while passing through resonance, a special design of the switchable pendulums that are controlled by centrifugal force is suggested. This design utilizes the only stable stationary orientation of the pendulums in the undercritical domain to position them in an appropriate way before coming into resonance. The results obtained provide new possibilities for the design of self-balancing devices for high precision applications.