An active balance system is provided for counterbalancing vibrations of an axially
reciprocating machine. The balance system includes a support member, a flexure
assembly, a counterbalance mass, and a linear motor or an actuator. The support
member is configured for attachment to the machine. The flexure assembly includes
at least one flat spring having connections along a central portion and an outer
peripheral portion. One of the central portion and the outer peripheral portion
is fixedly mounted to the support member. The counterbalance mass is fixedly carried
by the flexure assembly along another of the central portion and the outer peripheral
portion. The linear motor has one of a stator and a mover fixedly mounted to the
support member and another of the stator and the mover fixedly mounted to the counterbalance
mass. The linear motor is operative to axially reciprocate the counterbalance mass.