A robust spindle motor is provided having improved shock resistance for
fluid containment, as well as enhanced air purging characteristics. In an
aspect, axial displacement of relatively rotating components is
restricted by utilizing a limiter situated adjacent to a limiter bushing
forming an axial limiter gap therebetween. A fluid channel, at least
partially diverging, extends from a hydrodynamic bearing to the axial
limiter gap, and continues to a region beyond the axial limiter gap. In
an aspect, an axially diverging slot is situated adjacent to the axial
limiter gap. Power is reduced by reducing viscous drag between relatively
rotating components, hydrodynamic bearing length is increased, and higher
stiffness of the hydrodynamic bearing is provided. Fluid volume may be
increased, thereby offsetting fluid evaporation losses and allowing for
the use of lower viscosity lubricants.