Suction structure in piston type compressor

A suction structure for allowing refrigerant to flow from a suction pressure region in a piston type compressor, wherein cylinder bores for accommodating a respective piston are arranged around a rotary shaft, wherein a cam body is formed with the rotary shaft, wherein the piston is engaged with the cam body so that rotation of the rotary shaft is transmitted to the piston, wherein a compression chamber is defined by the piston in the respective cylinder bore, wherein a valve mechanism is disposed adjacent to the compression chamber, the suction structure comprising:

• a shifting device for shifting between a connecting state and a disconnecting state, wherein in the connecting state the compression chamber is connected to the suction pressure region upstream the shifting device through the valve mechanism and in the disconnecting state the compression chamber is disconnected from the suction pressure region upstream the shifting device through the valve mechanism, the shifting device including;
• a valve body movable between a connecting position and a disconnecting position, wherein the connecting position corresponds to the connecting state and the disconnecting position corresponds to the disconnecting state;
• a return spring urging the valve body from the connecting position toward the disconnecting position;
• and
• a permanent magnet for attracting the valve body by magnetic force from the connecting position toward the disconnecting position.

A piston type compressor comprising:

• a housing;
• cylinder bores formed in the housing, wherein the cylinder bores are arranged around a rotary shaft;
• pistons accommodated in the respective cylinder bore;
• a cam body formed with the rotary shaft, wherein the piston is engaged with the cam body so that rotation of the rotary shaft is transmitted to the piston;
• a compression chamber defined by the piston in the respective cylinder bore;
• a rotary valve rotated integrally with the rotary shaft, wherein the rotary valve includes a supply passage for introducing refrigerant from a suction pressure region in the compressor to the compression chamber;
• and
• a shifting device for shifting between a connecting state and a disconnecting state, wherein in the connecting state an outlet of the supply passage is connected to the suction pressure region and in the disconnecting state the outlet of the supply passage is disconnected from the suction pressure region, the shifting device including;
• a valve body movable between a connecting position and a disconnecting position, wherein the connecting position corresponds to the connecting state and the disconnecting position corresponds to the disconnecting state;
• a return spring urging the valve body from the connecting position toward the disconnecting position;
• and
• a permanent magnet for attracting the valve body by magnetic force from the connecting position toward the disconnecting position.