A novel fluid pump includes a stator body defining a pumping chamber and
an impeller operationally disposed within the chamber. The impeller has
opposed ends with a central axis defining an axis of rotation. Passive
magnetic bearing sets are positioned along the impeller body with each
bearing set being similarly polarized so as to be in mutually attracting
or mutually repelling relationship. A third passive magnetic bearing set
is positioned along the impeller axis between the opposed ends with the
third bearing set being magnetically coupled similarly to the first and
second bearing sets, with the passive magnetic bearings creating an
unstable negative force in a plane perpendicular to the axis of rotation
of the impeller with the negative stiffness being overcome upon rotation
of the impeller creating a centrifugal force of a magnitude greater than
that of the unstable negative force.