Patent ID: 8419394
Filing Date: 2013-04-16
Classification: F01C,F04C

Abstract:
1. 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 in fluid communication with 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, wherein the oil pump is implemented as a variable capacity type oil pump, which forms a variable capacity as an inner gear and an outer gear thereof perform a relative motion while being rotationally engaged with each other; 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, an oil passage is formed at the crankshaft such that oil received in the variable capacity type oil pump from the oil separator is pumped to the oil passage; and a backflow preventing portion formed at a housing which accommodates the oil pump and configured to prevent oil from back-flowing from the inner space of the casing to the oil separator, wherein the backflow preventing portion is implemented as an oil pocket formed between the variable capacity type oil pump and the oil passage such that oil used to lubricate bearing surfaces of the crankshaft flows from the bearing surfaces into the oil pocket and flows from the oil pocket into the variable capacity type oil pump.