Patent ID: 8858196

Claim:
A compression device, comprising: a case; a stator within the case; a rotor within the stator; a crank shaft coupled to the rotor; a compressor, coupled to the crank shaft, to suction and compress a refrigerant and to discharge the compressed refrigerant into the case; a first bearing, coupled to the compressor, to support a first portion of the crank shaft; and a second bearing to support a second portion of the crank shaft spaced apart from the first portion, wherein a diameter of the crank shaft is greater than or equal to 0.114 times an outer diameter of the stator, and wherein the diameter of the crank shaft is less than or equal to 0.138 dines the outer diameter of the stator, wherein the compressor comprises: a cylinder coupled to the first bearing, the cylinder forming a compression space together with the first bearing; a rolling piston coupled to the crank shaft to perform an orbiting motion within the compression space of the cylinder; and a vane to partition the compression space into a suction chamber and a discharge chamber and linearly moving in response to the orbiting of the rolling piston, and wherein the second bearing comprises: a frame welded onto an inner circumferential surface of the case at one side of the stator; a housing coupled to the crank shaft so as to allow for rotation of the crank shaft, the housing being detachably coupled to the frame; a plurality of first protrusions located on an outer circumferential surface of the frame, the plurality of protrusions being welded onto the inner circumferential surface of the case and spaced apart from one another at predetermined intervals along a circumferential direction; and a plurality of second protrusions located on an outer circumferential surface of the housing for support at the frame, wherein a number of the plurality of first protrusions equals a number of the plurality of second protrusions, and wherein the plurality of first protrusions and the plurality of second protrusions overlap each other.