Non-friction pressure seal

Abstract

A seal between compression chambers of a compressor which preferably embodies a relatively long sleeve having an inside diameter only slightly larger than the diameter of a piston rod that extends between and in to the compression chambers. The sleeve is floatingly supported in and sealed against the housing of the compressor so as to enable it to adjust itself to always remain substantially concentric with respect to the rod without assuming appreciable bearing forces. Preferably the inner surface of the sleeve has a good bearing material on or imbedded in at least two end portions of the sleeve. The seal may also take the form of a long bore in a wall between areas of different gas pressures for preventing substantial leaking of gas lengthwise thereof between the wall of the bore and a movable rod, of slightly smaller diameter, which extends therethrough. Either one of the above mentioned seals may also be combined with a short length bearing, having an inside diameter which, when coated with a film of lubricant, is of substantially the same diameter as a movable rod extending through the bearing but smaller than the diameter of the seal bore. The bearing may be located anywhere between either end of the seal bore and the middle thereof.