Gear compressor

This invention discloses a kind of gear type compressor. It includes:moter; gear type compressing part which compresses refrigerants flowed from evaporator by driving power provided from moter; gear type expanding part which expands the refrigerants reabsorbed by condenser after outputting from compressing part. The gear type compressing part includes: main bearing fixed at the underside of electric engine; ring shaped compressing cylinder which connects to the underside of main bearing and forms oil groove on peripheral face; outer gear which is positioned at the inner space of compressing cylinder and can rotate; inner gear which is arranged at the inner side of outer gear and receives driving power provides from electric engine. It rotates by gearing into the outer gear and compresses refrigerants at the same time; compressing board which connects to the underside of compressing cylinder. Lubricating oils, which are provided to each cylinder and outer gear of expanding part and compressing part, diffuse to the whole surface of contact area to prevent mechanical loss due to friction.