Abstract: A multi-stage compressor is disclosed, which comprises: two motion converters driven by one driving shaft and converting a rotary motion to a straight-line reciprocating motion; first and second pistons (62) connected to one of the motion converters in opposite directions and moving reciprocatively in a straight line; and third and fourth pistons (72) connected to the other one of the motion converters in opposite directions, arranged at a predetermined angle with respect to the first and second pistons (62), and moving reciprocatively in a straight line, and which is characterized in that at least two of the four pistons operate for first-stage compression and at least one of the others operate for second-stage compression.

Abstract: A yoke structure for a compressor is disclosed, which is applied to a scotch yoke type reciprocating compressor. The yoke structure comprises a crankshaft (10); a crankpin (20) connected to the crankshaft (10), to rotate along a predetermined round trajectory which has the crankshaft at its pivot, as the crankshaft rotates; a frame having a pair of slide ways (41) formed on two parallel inner faces of the frame (40) opposing each other, one or more pistons (30) to be fixed to outer faces of the frame outside the slide (41) ways; a sliding block (30) positioned between the pair of slide ways (41) and rotatably connected to the crankpin (20); and a pair of self-lubricating materials (32) attached to the sliding block (30) so as to be in contact with opposing faces of the slide ways (41).

Abstract: A refrigeration system comprising: a heat absorption unit (300) for absorbing heat from a peripheral portion to fluid under a predetermined constant pressure; a first compression unit (410) for sucking the fluid discharged from the heat absorption unit (300) and compressing; an intermediate cooling unit (500) for cooling the fluid compressed in the first compression unit (410); a second compression unit (420) for re-compressing the fluid discharged from the intermediate cooling unit (500); a heat radiating unit (100) for radiating heat from the fluid compressed in the second compression unit (420) and discharged to a peripheral portion under a predetermined constant pressure; an expansion unit (200) for lowering pressure of the fluid which passed through the heat radiating unit (100) by an adiabatic expansion and driving the first and second compression units by work generated from the expansion; and a cooling flow path (510) for passing the fluid discharged from the expansion unit (200) through the intermedi

Abstract: A multi-stage compressor is disclosed, which comprises: two motion converters driven by one driving shaft and converting a rotary motion to a straight-line reciprocating motion; first and second pistons (62) connected to one of the motion converters in opposite directions and moving reciprocatively in a straight line; and third and fourth pistons (72) connected to the other one of the motion converters in opposite directions, arranged at a predetermined angle with respect to the first and second pistons (62), and moving reciprocatively in a straight line, and which is characterized in that at least two of the four pistons operate for first-stage compression and at least one of the others operate for second-stage compression.

Abstract: A yoke structure for a compressor is disclosed, which is applied to a scotch yoke type reciprocating compressor. The yoke structure comprises a crankshaft (10); a crankpin (20) connected to the crankshaft (10), to rotate along a predetermined round trajectory which has the crankshaft at its pivot, as the crankshaft rotates; a frame having a pair of slide ways (41) formed on two parallel inner faces of the frame (40) opposing each other, one or more pistons (30) to be fixed to outer faces of the frame outside the slide (41) ways; a sliding block (30) positioned between the pair of slide ways (41) and rotatably connected to the crankpin (20); and a pair of self-lubricating materials (32) attached to the sliding block (30) so as to be in contact with opposing faces of the slide ways (41).