Patent ID: 7407327

Claim:
A spindle motor comprising: a journal bearing defined between an inner component and an outer component, wherein the inner component and the outer component are positioned for relative rotation, and define a portion of a stationary component and a rotatable component; a fluid recirculation passageway including a first fluid passageway defined within the outer component, the first fluid passageway in fluid communication with a second fluid passageway, the second fluid passageway defined between the outer component and a radial member extending radially from the inner component, wherein the first fluid passageway and the second fluid passageway are in fluid communication with the journal bearing at separate locations; a shield, connected to one of the stationary component and the rotatable component, defining a reservoir with the outer component, wherein a recirculation plenum is defined by a junction joining the reservoir, the first fluid passageway and the second fluid passageway; means for creating an asymmetric pressure gradient within the fluid recirculation passageway, circulating fluid and purging air in the fluid, wherein the fluid circulates about a substantial portion of the journal bearing, the first fluid passageway, and the second fluid passageway, wherein means for creating the asymmetric pressure gradient, circulating fluid and purging air comprises spiral grooves defined on at least one of the radial member and the outer component to generate pumping pressure to drive fluid recirculation and to pump fluid from the second fluid passageway toward the inner component and into the journal bearing, when the inner component and the outer component are in relative rotational motion; and means for sealing the reservoir comprising at least one of a capillary seal defined between the shield and the outer component, and a grooved pumping seal formed by spiral grooves on at least one of the radial member and the shield adjacent to an outer diameter gap defined between the shield and an outer diameter of the radial member, the outer diameter gap joining the recirculation plenum junction.