Vane rotary compressor having a bearing with back pressure pockets

A vane rotary compressor, comprising:

• a casing;
• a motor located in the casing;
• a cylinder located in the casing;
• a main bearing positioned between the motor and the cylinder on one side of the cylinder;
• a sub bearing positioned opposite to the main bearing on an opposite side of the cylinder, the main bearing and the sub bearing being coupled to the cylinder and defining a compression space between the main bearing and the sub bearing, at least one of the main bearing or the sub bearing including a back pressure pocket disposed adjacent an inner circumferential surface of a respective one of the main bearing or the sub bearing;
• a roller positioned in the compression space, the roller including a plurality of circumferentially spaced apart vane slots extending into the roller from open ends on an outer circumferential surface of the roller to closed ends within the roller;
• a plurality of vanes slidably positioned in the vane slots, the vanes being separated from the closed ends of the vane slots by back pressure chambers, the vanes protruding from the open ends toward an inner circumferential surface of the cylinder;
• a rotation shaft having a first end coupled to the motor and a second end coupled to the roller, the rotation shaft extending through both the main bearing and the sub bearing;
• wherein at least one back pressure chamber of at least one of the vane slots is configured to communicate with at least one of the main bearing back pressure pocket or the sub bearing back pressure pocket, and
• wherein 2≤H/T≤6 when an axial depth of the at least one of the main bearing back pressure pocket or the sub bearing back pressure pocket is H and a radial width of the bearing protrusion portion is T.

A vane rotary compressor, comprising:

• a cylinder;
• a main bearing and a sub bearing coupled to the cylinder, the main bearing and the sub bearing forming a compression space together with the cylinder, the main bearing including a main bearing back pressure pocket and the sub bearing including a sub bearing back pressure pocket;
• a rotation shaft radially supported by the main bearing and the sub bearing;
• a roller including a plurality of vane slots spaced apart from each other along a circumferential direction, each vane slot including one end open toward an outer circumferential surface of the roller, and a back pressure chamber disposed adjacent an opposite end of the vane slot, the back pressure chamber being configured to communicate with at least one of the main bearing back pressure pocket or the sub bearing back pressure pocket;
• and
• a plurality of vanes slidably inserted into the vane slots, the vanes being configured to protrude in a direction toward an inner circumferential surface of the cylinder, the vanes being arranged so as to divide the compression space into a plurality of compression chambers,
• wherein the at least one of the main bearing back pressure pocket or the sub bearing back pressure pocket includes a plurality of pockets having different inner pressure along the circumferential direction,
• wherein the plurality of pockets include bearing protrusion portions formed on an inner circumferential side, the bearing protrusion portions forming radial bearing surfaces with respect to an outer circumferential surface of the rotation shaft,
• wherein the plurality of pockets include:
• a first pocket having a first pressure;
• and
• a second pocket having a second pressure higher than the first pressure,
• wherein a bearing protrusion portion of the second pocket includes a communication flow path through which an inner circumferential surface of the bearing protrusion portion communicates with an outer circumferential surface of the bearing protrusion portion, and
• wherein the bearing protrusion portions form an annular shape to substantially close an inner circumferential side of the plurality of pockets facing the rotation shaft, and
• wherein 2≤H/T≤6 when an axial depth of the at least one of the main bearing back pressure pocket or the sub bearing back pressure pocket is H and a radial width of the bearing protrusion portion is T.