Abstract: This invention relates to a twin-plate, rotary compressor and refers particularly, though not exclusively, to a twin-plate, rotary compressor comprising two conical plates for relative rolling motion within a casing, there being a line contact between the two conical plates; the line contact being maintainable during operation of the compressor; a central seal for sealingly engaging correspondingly-shaped recesses of the two conical plates; and an outer seal in mating relationship with the two conical plates; wherein the central seal is mounted on a drive shaft, the drive shaft being operatively connected to an output shaft of a motor; wherein the drive shaft, the central seal and the outer seal are for rotation about a third axis of rotation, the third axis of rotation being coincident with a longitudinal axis of the drive shaft and a center of the central seal.