Patent ID: 8714559

Claim:
A bearing seal for preventing contaminant ingress between a rotatable shaft and a bearing housing which supports the shaft for rotation about an axis, comprising: an annular cap located at a first end of the bearing housing where the shaft exits therefrom, the cap having an outer surface and a radial internal surface spaced from the shaft, the cap also having a passage formed therethrough which extends from the radial internal surface to the outer surface, wherein the passage is oriented substantially radially to the axis, the cap defining an annular volume residing between the radial internal surface and the shaft; and a distribution ring removably residing in the annular volume of the cap and defining inside and outside portions of the annular volume, the distribution ring having at least one substantially tangentially oriented duct formed therein that extends between the outside and inside portions of the annular volume, the distribution ring and the annular cap defining an annularly shaped axial flow path that extends axially from the inside portion of the annular volume, the axial flow path including a reduced diameter section located adjacent to the inside portion of the annular volume whereby upon supplying pressurized purge fluid through the passage to the outside portion of the annular volume, the at least one substantially tangentially oriented duct induces a tangential flow in the purge fluid as the purge fluid moves from the outside portion to the inside portion, thereby to create a circumferentially uniform fluid pressure alongside the shaft within the inside portion of the annular volume, so that the pressurized purge fluid traverses the axial flow path and eventually flows outwardly from between the shaft and the bearing housing in a circumferentially uniform manner, wherein the at least one substantially tangentially oriented duct has a first end and a second end and is longitudinally curved along its length therebetween and also has an outer section that is oriented substantially radially and an inner section that is oriented substantially tangentially.