Abstract: The invention relates to a motor and compressor assembly of the type in which the frame member of the compressor unit includes the bearing for the motor shaft and is bolted to only one side of the packet of the stator laminations of the motor unit. The invention is directed to the prevention of misalignment between the compressor and motor units attributable to the bolting of the compressor unit to only one side of the packet of laminations which results in the bolt pressures or forces acting to clamp the laminations closer together on the bolt side than on the other side. The bad effects of this are avoided with the present invention by providing slots in the packet of laminations in close proximity to the bolt holes therein in a manner so that approximately symmetrical characteristic bending moment curves are obtained along lines passing through the axis of each bolt hole and to both sides of the holes.

Abstract: The invention relates to a compressor of the type used in refrigeration systems. In these compressors the piston pin in the transversely extending piston bore is of lesser length than the diameter of the piston such that undesired chambers are formed at opposite ends of the pin. The stroke is normally of a length that the piston pin and these chambers intersect the lower edge of the cylinder. Gas trapped in these chambers expands rapidly with an undesired popping noise when fluid communication is established at the end of the down stroke between the chambers and the interior of the crankcase. Throttling passages are provided between these chambers and the interior of the crankcase to prevent pressure build-up in the chambers and the accompanying popping noise.

Abstract: The invention relates to an electric motor and piston type compressor unit used for small refrigerators. The housing or cylinder of the compressor is attached to the motor casing and these two members, as a unit, are resiliently mounted in a sealed housing. In order to minimize the overall size of the unit, and specifically the outer housing, the piston connecting rod has a special shape at its crank end to facilitate the initial installation of the piston and connecting rod. The crank end of the connecting rod has a larger bore than the crankpin and the shape of the crank end is characterized by a recess which allows the crank end to clear the crankpin while being moved into surrounding relation to the crankpin after which a sleeve is installed between the crank end and the crankpin. The recess is strategically located so that while it facilitates the assembly operation there is no compromise or sacrifice with regard to the maximum loads the connecting rod can withstand.