A reciprocating pump includes a drive section and a pump section. The
drive section has a reciprocating coil assembly to which alternating
polarity control signals are applied during operation. A permanent magnet
structure of the drive section creates a magnetic flux field which
interacts with an electromagnetic field produced during application of
the control signals to the coil. The coil assembly includes a drive
member that drives a plunger assembly having a plunger and a valve stem
movably interfitted within the plunger and having a lower poppet head. As
the plunger is driven downwardly the plunger contacts the poppet head to
drive it into the pump chamber to force the fluid therefrom. There is a
gap between the poppet head and the plunger so that the initial downward
movement of the plunger closes the gap to gain momentum before it
contacts the poppet head and drives it downwardly.