Hermetically sealed compressor having oil supply mechanism based on refrigerant pressure

A hermitically sealed compressor comprising:

• an electrically-driven element;
• a rotary compressing element driven by the electrically-driven element to compress refrigerant;
• the rotary compressing element having a primary bearing, a secondary bearing and at least one cylinder that is sandwiched between the primary and secondary bearings and has a refrigerant inlet through which a refrigerant is adapted to flow under refrigerant suction pressure and a discharge outlet through which compressed refrigerant is adapted to flow under refrigerant discharge pressure and including a compression chamber in which the refrigerant is compressed;
• a hermetically sealed container in which the electrically-driven element and the rotary compressing element are accommodated and oil is stocked,
• a refrigerant suction path for sucking refrigerant and feeding the sucked refrigerant into the compression chamber;
• an oil stock portion for stocking the oil;
• an oil path for injecting the oil into the compression chamber when the refrigerant is sucked into the compression chamber of the cylinder constituting the rotary compressing element;
• and
• an opening/closing valve for opening/closing the oil path in accordance with the refrigerant discharge pressure of the rotary compressing element or the pressure of the compressed refrigerant compressed by the rotary compressing element such that oil is supplied into the compression chamber when the refrigerant discharge pressure or the pressure of the compressed refrigerant is low, said valve including biasing means for moving the valve to the open position, wherein the oil path includes an oil flowing groove that is formed between the cylinder and one of the primary bearing and the secondary bearing and intercommunicates with the compression chamber and the oil stock portion, the opening/closing valve is disposed in the oil path, and the oil is adapted to flow from the oil stock portion through the oil flowing groove formed between the cylinder and one of the primary and secondary bearings into the compression chamber interlocking with the opening of the open/closing valve;
• wherein the oil flowing groove comprises a first oil path penetrating from the outer peripheral surface to the oil stock portion, a second oil path that penetrates through the primary bearing in the thickness direction of the primary bearing and intercommunicates with the first oil path at one end thereof, a third oil path that is formed in the cylinder so as to intercommunicate with the other end of the second oil path and the compression chamber, and a fourth oil path that is formed around an outer periphery of the opening/closing valve so as to intercommunicate with the third oil path when the refrigerant discharge pressure of the pressure of the compressed refrigerant is low.