Hermetic type scroll compressor and refrigerating and air-conditioning apparatus

A hermetic type scroll compressor comprising:

• a scroll compressor element in which an end plate of a orbiting scroll and an end plate of a fixed scroll are assembled such that they slide against each other,
• an electric motor element which drives the scroll compressor element,
• a hermetic casing which houses the scroll compressor element and the electric motor element and which holds lubricating oil collected at a bottom thereof, and
• an oil separator disposed on a discharge side of the scroll compressor element;
• wherein an interior of the hermetic casing is kept at an intermediate pressure between a suction pressure and a discharge pressure,
• wherein an oil return mechanism is provided, which intermittently returns lubricating oil from the oil separator into the hermetic casing, and
• wherein an oil supply mechanism is provided, which intermittently introduces lubricating oil from around a circumference of the end plate of the orbiting scroll to the sliding parts of the end plate of the orbiting scroll and the end plate of the fixed scroll.

A refrigerating and air-conditioning apparatus having a refrigeration cycle system in which a hermetic type scroll compressor, a gas cooler, an expansion valve and an evaporator are connected with refrigerant piping:

• wherein carbon dioxide is used as a refrigerant for the refrigeration cycle system;
• wherein an interior of a hermetic casing of the hermetic type scroll compressor is kept at an intermediate pressure between a suction pressure and a discharge pressure;
• and
• wherein the hermetic type scroll compressor includes;
• a scroll compressor element in which an end plate of a orbiting scroll and an end plate of a fixed scroll are assembled such that they slide against each other,
• an electric motor element which drives the scroll compressor element,
• the hermetic casing housing the scroll compressor element and the electric motor element and holding lubricating oil collected at a bottom thereof,
• an oil separator disposed on a discharge side of the scroll compressor element, and
• an oil return mechanism which intermittently returns lubricating oil from the oil separator into the hermetic casing.