Patent ID: 6095768
Filing Date: 2000-08-01
Classification: F04B

Abstract:
A hermetic motor-driven compressor for refrigerators, comprising:a hermetic housing (10), anda motor-driven compressor unit (12) suspended in the housing (10) and in turn comprising:an electric motor (14) with a stator (16) and a rotor (20) defining an axis of rotation,a compressor block (36) situated at one axial end of the motor (14), fixed to the stator (16), and incorporating a bearing (62) centred on the axis of rotation,a crankshaft (46) comprising a straight portion (48) which extends through the rotor (20) along the axis of rotation, is fixed to the rotor, and extends through the bearing (62) of the block (36) with a spheroidal coupling, the crankshaft (46) further comprising a crank (50) situated on the farther side of the block (36) from the motor (14) and having a crank pin (54),a compressor cylinder (66) fixed to the block (36) in the region of the crank (50) and having an axis which intersects the axis of rotation perpendicularly,a piston (68) slidable to and fro in the cylinder (66) and incorporating an articulation member (70), anda connecting rod (72) which interconnects the crank pin (54) and the articulation member (70) of the piston,characterized in thatit comprises a casing (24) which encloses the stator (16) of the electric motor (14) externally and to which the stator is fixed, the casing (24) carrying and being fixed firmly to the block (36) of the compressor and further comprising a transverse wall (28) which is situated at the opposite end to the block (36) and is intersected by the axis of rotation, and through which the straight portion (48) of the crankshaft (46) extends,and in thatthe block (36) and the transverse wall (28) have respective annular seats (56, 60) which are concentric with the axis of rotation, and of which the annular seat (56) of the block (36) contains a main self-aligning bearing (62) and the annular seat (60) of the transverse wall (28) of the casing (24) contains a secondary self-aligning bearing (64), the straight portion (48) of the crankshaft (46) being mounted in both of these bearings (62, 64).