COMPRESSOR

PURPOSE:To reduce the dispersion in passage resistance by fitting a seal ring midway in a differential pressure supply passage in a loosely fit state and constructing it as a passage in a form of minute gaps. CONSTITUTION:A seal ring 16 is pressed against the sliding edge surface 13 of a side plate 2 due to the differential pressure produced when lubricating oil passes through the minute gaps of the seal ring 16, while being rotated by the frictional force produced between it and the outer surface 14 of an eccentric shaft 10. The pressure of lubricating oil is reduced by the gaps between the pressing surface of the seal ring 16 and the rotating shaft surface, and further reduced at a throttled passage 21 before flowing into a suction side passage 20. Thereby the passage resistance is affected only by the inside-diameter accuracy of the seal ring and the outside-diameter accuracy of the eccentric shaft, thereby also reducing the dispersion of the passage resistance.