| 摘要 |
A ring assembly, including a first oil scraper ring, a center oil scraper ring and a gas seal ring, adapted for disposition in a single groove of a packing cup which can be stationarily mounted over and around a reciprocally movable piston rod of a gas compressor. The function of the assembly is to both scrape lubricating oil from the piston rod for return to one side of the cup and to provide a seal against gas leakage from an opposite side of the cup, both along the piston rod under the seal ring and between the seal ring and opposing sides of the center ring and groove to prevent mixing of gas with the oil and escape of gas from the compressor. The center ring features a tapered outer peripheral surface portion. An annular side loading element, which can be a garter spring, is mounted in compression around the center ring so as to bear against the tapered surface portion and against an adjacent side of the first ring. The element thus side loads the first ring, by urging it against one side of the groove and oppositely side loads the center ring and seal ring to force one against the other and to urge the seal ring tightly against an opposite side wall of the groove to effect a satisfactory gas seal. The first ring and center ring, together, provide three separate and axially spaced apart oil scraper edges.
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