PISTON COMPRESSOR FOR OILLESS COMPRESSION

PURPOSE: To prevent oil from invading the interior of a cylinder by arranging a porous ring on a piston rod to suck up oil droplets flung off from an oil scraper ring or an oil film rising along the piston rod. CONSTITUTION: A piston compressor exhibits at least one piston 7 which is supported to be relatively free and connected via a piston rod 6 to a crosshead 5. The piston rod slides in a guide bearing 8 next to the crosshead and in a gland 11 next to a cylinder. A ring 15 of a porous material is arranged on the piston rod 6 between the guide bearing 8 and the gland 11. The ring 15 exhibits a circumferential groove which is intended for receiving a tubular spring and a depth of the groove measured from outside transversely to a longitudinal axis 6' of the piston rod is at least as great as an outer diameter of one turn of the tubular spring.