WHIRL SUPPRESSION IN HAND-HELD POWER TOOL ROTORS USING GUIDED ROLLINGBALANCERS

Residual unbalance in hand-held power tool rotors transmits undesirabl e vibrations to the hand of its operator. These vibrations can be effe ctively suppressed using an automatic balancing element constrained to move in a circular path. In an earlier analysis, the effectiveness of the balancing element on the unbalance rotor vibration suppression wa s investigated by assuming smooth contact between the balancing elemen t and its guide. The influence of the rolling motion of the balancing element due to friction at the contact is examined in the present stud y using a three-degree-of-freedom system model in a rotating reference frame. Investigation shows that the rolling motion in a carefully des igned balancer improves its stability and its effectiveness in vibrati on reduction. (C) 1998 Academic Press.