Parametric studies on modified configurations of ball-type passive balancers for improved transient and steadystate responses

A passive balancing device is a bearing with a set of masses that are free to move about a shaft axis of rotation. Beyond the first critical speed of the shaft, the masses assume positions that reduce vibrations due to imbalance. The conventional design of passive balancers is a dual-ball bearing. This type of balancer only performs its function at supercritical speeds and when the ball/track contact is nearly frictionless. In this work, additional experimental verification of a previously formulated mathematical model is conducted using published experimental data. The model was then used to investigate passive balancing performance numerically. Conventional and non-conventional bearing configurations were tested with consideration of rolling resistance and ball collisions. Results suggest that when rolling resistance is considered, a 1-track bearing configuration with any number of balls yields better performance than multi-track bearings. The 1-track configuration improved performance by 57% when compared to a 3-track configuration at supercritical steadystate. It is also shown that a multi-partition balancer improves performance significantly during shaft speed up – 69% improvement compared to a balancer without partitions. With configuration adjustments, the bearing remains entirely passive while vibration suppression performance is improved.