Arrangement of the oil feed apertures on a screw compressor

摘要

The invention relates to a screw compressor with two rotors. Oil is injected for the cooling, lubrication and sealing of the internal gap. The rotary movement of the rotors opens and closes the oil feed apertures by covering and freeing these. In the open position the inlet and outlet of the gap pair are closed and the pressure therein lower than the compression outlet pressure. The object of the invention is to improve the efficiency by arranging the oil feed apertures so that the drive losses due to friction and delivery of the oil are minimised and the cooling action maximised without adversely affecting the lubricant and sealing effect. According to the invention the oil feed apertures are always connected to the gap pair, which runs behind the expelling gap pair. The open position begins when the expelling gap pair has reached the outlet aperture. The oil feed aperture is closed by the respective following tooth once the expelling process is completed. The invention is particularly suited to the compression of oil-soluble gases.