A method and apparatus for a conical bearing is provided having a seal
shield having an angle supported from the hub or sleeve which surrounds
the shaft, and extending at an angle toward the outer surface of the shaft
and spaced slightly away from the upper angular surface of the cone. As
the cone and seal shield rotate relative to one another, fluid is drawn
toward the lower inner region of the reservoir. However, due to shock or
the like, some fluid may reach the radial gap between the end of the
shield and the outer surface of the shaft, therefore, a ring is either
incorporated into the upper end of the cone or pressed against the axial
outer end of the cone, defining an axial gap which is smaller than the
radial gap. In a preferred form of the invention, the ratio is about 1:3.
When oil is introduced to either of the two gaps (typically by shock), it
transfers or typically comes to rest in the axial gap, since the capillary
attractive force increases as the gap size decreases; therefore, with the
axial gap being smaller than the radial gap the oil will tend to transfer
to the axial gap. As the seal is spun up as the shield and cone rotate
relative to one another, centrifugal force acting on the oil in the axial
gap transfers the oil radially away from the radial gap and into the
reservoir defined between the shield and the cone. This transfer typically
happens in two stages. First the oil in the radial gap is transferred into
the axial gap, typically in the first few seconds of operation. The oil
remaining in the axial gap then transfers into the reservoir volume due to
centrifugal pumping.
