Rotary compressor

A rotary compressor comprising:

• a sealed and vertical cylindrical compressor housing provided with a refrigerant discharge portion at an upper portion and a refrigerant suction portion at a lower portion;
• a compression unit arranged at a lower portion of the compressor housing and configured to compress refrigerant that is sucked from the suction portion and to discharge the refrigerant from the discharge portion;
• and
• a motor arranged at an upper portion of the compressor housing and configured to drive the compression unit, wherein
• the compression unit includes
• an annular upper cylinder and an annular lower cylinder,
• an upper end plate closing an upper side of the upper cylinder, and
• a lower end plate closing a lower side of the lower cylinder,
• an intermediate partition plate arranged between the upper cylinder and the lower cylinder, and closing a lower side of the upper cylinder and an upper side of the lower cylinder,
• a rotating shaft supported by a main bearing portion provided on the upper end plate and by a sub-bearing portion provided on the lower end plate, and rotated by the motor,
• an upper eccentric portion and a lower eccentric portion provided on the rotating shaft with a phase difference of 180 degrees from each other,
• an upper piston fitted in the upper eccentric portion and configured to revolve along an inner peripheral surface of the upper cylinder and form an upper cylinder chamber in the upper cylinder,
• a lower piston fitted in the lower eccentric portion and configured to revolve along an inner peripheral surface of the lower cylinder and form a lower cylinder chamber in the lower cylinder,
• an upper vane projecting into the upper cylinder chamber from an upper vane groove provided on the upper cylinder, and brought into contact with the upper piston so as to section the upper cylinder chamber into an upper suction chamber and an upper compression chamber,
• a lower vane projecting into the lower cylinder chamber from a lower vane groove provided on the lower cylinder, and brought into contact with the lower piston so as to section the lower cylinder chamber into a lower suction chamber and a lower compression chamber,
• an upper end plate cover covering the upper end plate, forming an upper end-plate cover chamber between the upper end plate and the upper end plate cover, and having an upper end-plate cover discharge hole communicating with the upper end-plate cover chamber and an inside of the compressor housing,
• a lower end plate cover covering the lower end plate and forming a lower end-plate cover chamber between the lower end plate and the lower end plate cover,
• an upper discharge hole provided on the upper end plate and communicating with the upper compression chamber and the upper end-plate cover chamber,
• a lower discharge hole provided on the lower end plate and communicating with the lower compression chamber and the lower end-plate cover chamber, and
• a refrigerant passage hole running through the lower end plate, the lower cylinder, the intermediate partition plate, the upper end plate, and the upper cylinder, and communicating with the lower end-plate cover chamber and the upper end-plate cover chamber,
• the lower end plate includes a lower discharge valve of a reed valve type configured to open and close the lower discharge hole, a lower discharge-valve accommodating recessed portion that extends in a groove shape from the lower discharge hole and into which the lower discharge valve is accommodated, and a lower discharge-chamber recessed portion formed so as to overlap with the lower discharge hole side of the lower discharge-valve accommodating recessed portion and communicate with the refrigerant passage hole,
• the lower end plate cover is formed in a flat-plate shape and is provided with a bulging portion having a portion facing the lower discharge hole,
• the lower end-plate cover chamber is formed by the lower discharge-valve accommodating recessed portion, the lower discharge-chamber recessed portion, and the bulging portion, and
• the bulging portion has a volume of 1/18 or greater and 1/9 or less of a total of air volumes of the upper compression chamber and the lower compression chamber.