Various "contactless" bearing mechanisms including hydrodynamic andmagnetic bearings are disclosed for a pump (such as a pump for pumping blood),asalternatives to mechanical contact bearings. In one embodiment, a pumpincludes a housingassembly, center post, rotor, and rotor suspension system comprised of apassive magneticbearing and hydrodynamic thrust bearing. The passive magnetic bearing iscomprised of atleast a first magnet assembly disposed in the rotor and a second magnetassembly disposed inthe center post. The hydrodynamic thrust bearing is comprised of at least onecontouredsurface disposed between the rotor and housing assembly. The first and secondmagneticassemblies each comprise at least one magnet. The first magnet assembly is pre-positioned tobe offset axially from the second magnetic assembly to exert an axial biasingforce on therotor. A method of suspending a rotor in a pump during pumping is alsodisclosed.
