Abstract: A motor-driven compressor comprises a drive shaft driven by an electric actuator and acting on a crank mechanism having a crank with which a connecting rod is associated eccentrically, the connecting rod supporting a piston movable in a corresponding cylinder. The cylinder has a longitudinal axis W inclined to the axis X of the drive shaft at an angle other than 90 n degrees so that the connecting rod supporting the piston has a longitudinal axis K which intersects the plane in which the crank lies.

Abstract: A method for and an apparatus for assembly of rotating ring rotary compressors is disclosed. A cylinder, shaft, roller and supports are initially assembled together, fixing means being kept in a slackened position. A preliminary centering operation is then carried out for bringing the axis of the shaft into a diametral plane of the cylinder constituting a predetermined reference plane. This operation is carried out by orientation of the shaft into two angular positions spaced from each other by 180.degree.. The shaft is then oriented relative to the cylinder, the region of maximum eccentricity of the core being brought into the said reference plane. The support and the cylinder (this latter with the interposition of the roller) are then pressed onto the shaft by a thrust exerted in the said predetermined plane.

Abstract: The motor compressor comprises a hermetic casing in which are mounted a reciprocating compressor and a reversible electric motor having a common vertical shaft with an axial duct for conveying lubricating oil from a centrifugal pump located at the lower end of the shaft to an outlet located at its upper end. The outlet of the axial duct is constituted by an elbow tube which is fixed to the upper end of the shaft and has an inclined end portion extending upwardly and radially outwardly with respect to the axis of the shaft.