Centrifuge having self-lubricating bearing

Claim 1

IN A CENTRIFUGE COMPRISING A HOLLOW ROTOR MOUNTED FOR ROTATION ABOUT A VERTICAL AXIS, THE ROTOR HAVING AN IMPERFORATE PERIPHERAL WALL WITH PORTS FOR DISCHARGE OF SEPARATED SOLIDS AND LIQUID, RESPECTIVELY, A HELICAL CONVEYOR MOUNTED FOR ROTATION IN BEARING MEANS WITHIN THE ROTOR AND ADAPTED TO MOVE SOLIDS TOWARD THE SOLIDS DISCHARGE PORT, MEANS TO DELIVER A FEED SLURRY INTO THE ROTOR, MEANS TO DRIVE THE ROTOR AND THE CONVEYOR AT DIFFERENT SPEEDS; THE IMPROVEMENT WHEREIN THE BEARING MEANS INCLUDES A LOWER BEARING ASSEMBLY COMPRISING A DOWNWARDLY EXTENDING SPINDLE SECURED TO THE LOWER END OF THE CONVEYOR, A HUB PORTION SECURED TO THE LOWER END OF THE ROTOR AND HAVING A CENTRAL OPENING WITH A CIRCULAR WALL, THE OPENING RECEIVING THE SPINDLE, AN OUTWARD ANNULAR PROJECTION MOUNTED ON THE SPINDLE BELOW THE OPENING, A BUSHING OF RESILIENT PLASTIC SURROUNDING AND ENGAGING ABOUT THE SPINDLE INSIDE THE OPENING AND ENGAGING THE CIRCULAR WALL OF THE OPENING, UPPER AND LOWER WASHERS SURROUNDING THE SPINDLE ABOVE AND BELOW THE BUSHING, RESPECTIVELY, AN UPPER ANNULAR SEAL OF RESILIENT PLASTIC DISPOSED INTERMEDIATE THE UPPER WASHER AND THE HUB AND A LOWER ANNULAR SEAL OF RESILIENT PLASTIC DISPOSED INTERMEDIATE THE LOWER WASHER AND THE ANNULAR OUTWARD PROJECTION, UPPER SPRING MEANS ON THE CONVEYOR URGING THE UP-