Patent ID: 8601933
Filing Date: 2013-12-10
Classification: F04B

Abstract:
1. A hermetic compressor, comprising: an airtight container having a compression element and a motor element, the compression element being configured to be driven by the motor element for compressing a refrigerant, the compression element including: a crankshaft extending in a vertical direction, the crankshaft having a main shaft and an eccentric part; a block forming a compression space; a piston having a cylindrical shape, the piston reciprocating in the compression space; and a connecting rod for transmitting rotation of the eccentric part to the piston, wherein the piston has a center of gravity on one of an upper side and a lower side in the vertical direction with respect to a plane, the plane passing through a central axis of the piston and being perpendicular to the crankshaft, and the upper side and the lower side in the vertical direction of the piston are different from each other in volume, and the piston is provided on an outer peripheral surface thereof with a concavely recessed portion recessed radially inwardly, the concavely recessed portion including a first concavely recessed portion on the upper side in the vertical direction and a second concavely recessed portion on the lower side in the vertical direction, the first concavely recessed portion and the second concavely recessed portion being different from each other in volume.