SEALING DEVICE FOR GAS COMPRESSOR-EXPANDER

摘要

A piston rod (22) is provided slidably through a partition wall (19) between a behind-piston space (21) and a crank case (12). A sealing device (9) surrounding the piston rod (22) comprises a first sealing member (93) having a high sealing capability against a flow from the crank case (12) to the behind-piston space (21), an intermediate chamber (91) provided on the behind-piston space side of the first sealing member (93), a communication passage (96) for communication between the intermediate chamber (91) and the crank case (12), and an oil filter (97) provided at a portion of the communication passage (96). This arrangement not only extends the service life of the sealing device but also prevents the refrigerating capacity of the gas compressor-expander from being lowered.