Rotary fluid coupling

Abstract

The rotary fluid coupling decreases the possibility of microcontaminates entering the fluid flow line and is thus especially suitable for processing equipment in manufacturing of wafers and other components for the microcomputer industry. The rotary fluid coupling interconnects a fluid conveying passageway and a spindle element to a duct in a second element such that the two elements are rotatable with respect to each other. An axial channel is provided along the length of the spindle. A planar faced plate is mounted on the spindle. A bore in the spindle plate is in axial alignment with the spindle channel, generally forming a single continuous fluid conveying passageway. A second element has a generally planar distal faced plate. A fluid conducting duct extends from an aperture on the distal face of the second plate to a fluid source with the two faces generally aligned in parallel relationship to each other creating a fluid permeable gap. A fluid flow resistant labyrinth may be provided on one or both faces. In use, fluid flowing from the fluid source through the fluid conducting duct and the aperture in the second element crosses the fluid permeable gap to enter the fluid conveying passageway in the spindle elements. Synthetic resin coating is further provided within the fluid conveying passageway of the spindle element serving to prevent microcontaminates from being generated by corrosion of the metallic surface by the action of the fluid flowing therethrough.