Nuclear fuel handling grapple carriage with self-lubricating bearing

Claim 1

Nuclear fuel handling apparatus including a fuel transfer tube disposed on a closure head of a vessel containing fuel assemblies and extending from said closure head downward into a pool of coolant, tracks attached to the inside of said fuel transfer tube, a grapple carriage disposed in said fuel transfer tube, a grapple attached to the underside of said grapple carriage for engaging said fuel assemblies, a grapple control mechanism disposed on said closure head and attached to said grapple carriage and said grapple for lifting and lowering said grapple carriage and for controlling said grapple, and wheels attached to said grapple carriage for guiding said grapple carriage along said tracks, a bearing for each of said wheels, each of said bearings comprising: an inner race mounted on an axle; roller element bearings disposed in said inner race; an outer race disposed around said inner race and enclosing said roller element bearings between said inner and outer races, said roller element bearings allowing said outer race to rotate relative to said inner race; alignment means disposed on said axle and adjacent said outer race for maintaining alignment of said outer race with respect to said inner race while allowing rotation of said outer race; a reservoir disposed in said axle in fluid communication with said roller element bearings and capable of being filled with coolant when said axle is submerged in said pool of coolant for supplying said coolant to said roller element bearing, thereby lubricating said roller element bearings; and supply means establishing fluid communication between said reservoir and said roller element bearings for permitting said coolant to flow from said reservoir and between said outer race and said alignment means establishing an outward flow of said coolant thereby preventing impurities from seeping inward.