Patent ID: 8342827

Claim:
A hermetic compressor, comprising: a casing configured to store oil in an inner space of the casing; a driving motor installed within the inner space of the casing; a compression unit installed within the inner space of the casing and configured to compress a refrigerant when driven by the driving motor; an oil separator fluidly coupled to an outlet of the compressor and configured to separate oil from the compressed refrigerant discharged from the compression unit; an oil pump in fluid communication with the oil separator and configured to pump oil separated by the oil separator into the inner space of the casing; and a crankshaft coupled to the driving motor, the compression unit, and the oil pump and configured to transmit a driving force of the driving motor to both the compression unit and the oil pump, the oil stored in the inner space of the casing flows through a length of the crankshaft within an oil passage of the crankshaft; and the oil pump comprises a first oil pump and a second oil pump, the first oil pump configured to pump recollected oil separated from the refrigerant by the oil separator to the casing, and the second oil pump configured to pump oil stored in the inner space of the casing into the oil passage of the crankshaft, wherein an outlet of the first oil pump is disposed at a position lower than an inlet of the second oil pump, an upper housing having a first pumping space which accommodates the first oil pump therein is installed within the casing, an intermediate housing having a second pumping space for accommodating the second oil pump therein is installed on a bottom surface of the upper housing, a lower housing having a communication groove which communicates the second pumping space with the oil passage of the crankshaft is installed on a bottom surface of the intermediate housing, the inlet of the first oil pump is formed by a first suction passage which consecutively penetrates the lower housing and the intermediate housing, and the outlet of the first oil pump is formed by a first discharge passage which consecutively penetrates the intermediate housing and the lower housing and leads to the inner space of the casing, and an inlet of the second oil pump is formed by a second suction passage of the lower housing, and an outlet of the second oil pump is formed by the communication groove.