{HEAD ~ at least one stator} comprising {TAIL ~ stator teeth} and a coil operable to produce an alternating magnetic field exerting alternating axial forces on the buried magnet system that has a self centering force and a required stiffness to reciprocate at a frequency near an alternating current supply frequency; and 
comprising
{ HEAD ~ at least one stator } comprising { TAIL ~ stator teeth } and a coil operable to produce an alternating magnetic field exerting alternating axial forces on the buried magnet system that has a self centering force and a required stiffness to reciprocate at a frequency near an alternating current supply frequency ; and
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH