Scroll compressor with enhanced discharge port - U.S. Patent 5,022,834

A scroll compressor has a pair of mating scrolls that are disposed on parallel, eccentric axes, and each of these scrolls has a scroll plate and a spiral, involute wrap. The scrolls are driven so that one of them orbits about the axis of the other scroll while maintaining a fixed azimuthal relationship to it. The orbital motion causes a compressible fluid to enter at the periphery of the scrolls, and be carried and compressed by pockets formed between the mating wraps of these scrolls. The compressed gas is discharged out a discharge port at the center of one of the scrolls. The discharge port is bored diagonally into the scroll plate of the one scroll so that it has an elongated elliptical aperture at the center of the scroll plate. The port is machined into the scroll from the wrap side of the scroll. The enlarged size of the port aperture reduces the resistance to fluid flow and hence reduces the back pressure, thereby increasing the compressor efficiency