Patent ID: 6234414
Filing Date: 2001-05-22
Classification: B02C,F16J

Abstract:
Apparatus having a fluid purge system operating in conjunction with a shaft, packing and/or other portions of the apparatus, said apparatus comprising:a material processing chamber including a zone in which material is present which should be substantially barred, during operation of the apparatus, from escaping through the packing,a moveable shaft havinga longitudinal axis andone or more surfaces,a material-contacting member connected with the shaft and present at least partly within the chamber during at least a portion of the motion of the shaft and said member,at least one bearing in which the shaft moves,a cavity surrounding a portion of the shaft in communication with said zone,packing located in the cavity between said zone and the bearing and held in sealing engagement with at least one surface of the shaft,a substantially rigid ring memberlocated in an enclosure surrounding said shaft andhaving at least one ring member surface located between said zone and the packing and positioned in confronting but spaced relationship with at least one portion of the shaft surface to define at least one small clearance between the confronting surfaces of the ring member and shaft,at least one fluid supply passage extending from outside the ring enclosure to said clearance,at least one first centering member connected with said ring member, including at least one first centering surface at least partly inclined to either side of a reference plane perpendicular to the axis of the shaft andat least one second centering member connected with a wall of the ring member enclosure, including at least one second centering surface at least partly inclined to either side of said reference plane and complementary to said first centering surface,the positions of said first and second centering surfaces each being established with respect to the shaft axis so that, when the first and second centering surfaces are brought into contact with one another, the ring member surface is in a predetermined radial position with respect to the portion of the shaft confronted thereby.