Vane rotary compressor

A vane rotary compressor, comprising:

• a cylinder;
• a main bearing and a sub bearing coupled to the cylinder to form a compression space together with the cylinder, wherein each of the main bearing and the sub bearing includes a divided back pressure pocket formed on a surface facing the cylinder, the divided back pressure pocket including a first pocket having a first inner pressure and a second pocket having a second inner pressure higher than the first inner pressure;
• a rotation shaft radially supported by the main bearing and the sub bearing;
• a roller rotatably supported within the cylinder between the main bearing and the sub bearing, the roller being configured such that an outer circumferential surface of one side of the roller is positioned in close proximity with an inner circumferential surface of the cylinder at a contact point, the roller including a plurality of vane slots formed along a circumferential direction of the roller, with each of the vane slots including one end opened toward the outer circumferential surface of the roller, and a back pressure chamber formed at the opposite end of the vane slot and in fluid communication with the divided back pressure pocket;
• and
• a plurality of vanes slidably supported in the vane slots of the roller, and protruding in a direction toward the inner circumferential surface of the cylinder with the plurality of vanes dividing the compression space into a plurality of compression chambers,
• wherein the compression space is provided with an inlet port and an outlet port formed at both sides of the contact point, and
• wherein each of the vane slots includes a stepped portion adjacent to the back pressure chamber, wherein the stepped portion forms a vane stop surface configured to restrict the vane from moving backwards into the back pressure chamber in contact with the rear surface of the vane when a compression chamber formed ahead of the vane slidably supported in the vane slot in a direction of rotation of the roller is at its highest pressure prior to discharge of fluid from the compression chamber through the outlet port.