Compressor

A compressor comprising:

• a drive shaft that is rotational about a shaft axis;
• a housing that rotationally supports the drive shaft and has a rotor chamber, wherein the rotor chamber is annular and is parallel with the shaft axis;
• an annular rotor located in the rotor chamber, wherein the annular rotor has a plurality of cradle windows radially extending there through and a circumferential surface extending in a direction parallel with the shaft axis, wherein the annular rotor is rotational together with the drive shaft while sliding on the housing at the circumferential surface;
• and
• a cradle provided in each of the cradle windows and configured to pivot about a pivot axis parallel with the shaft axis, wherein each of the cradles includes an outer contact surface that continually contacts an annular rotor chamber inward surface of the rotor chamber so as to divide the rotor chamber into outer operation chambers as the rotor rotates, wherein the cradles slide on the housing at pivoting ends, which extend in directions parallel with the shaft axis, as the rotor rotates, wherein the rotor chamber includes:
• the outer operation chambers located radially outside of the rotor, and
• inner operation chambers located radially inside of the rotor,
• the cradles, the outer operation chambers and the inner operation chambers form compression chambers, which change in volume by rotation of the rotor, while maintaining the airtightness, and
• the rotor chamber is defined by:
• the annular rotor chamber inward surface, which is parallel with the shaft axis,
• an annular rotor chamber outward surface, which is surrounded by the annular rotor chamber inward surface and parallel with the shaft axis,
• a rotor chamber front end surface, which is perpendicular to the shaft axis, and
• a rotor chamber rea rend surface, which is perpendicular to the shaft axis,
• the rotor includes:
• a rotor outer circumferential surface, which extends from the rotor chamber front end surface to the rotor chamber rear end surface, while contacting, from inside, the rotor chamber inward surface, and
• a rotor inner circumferential surface, which extends from the rotor chamber front end surface to the rotor chamber rear end surface, while contacting, from outside, the rotor chamber Outward surface, and
• the cradles include:
• the outer contact surface, which contacts, from inside, the rotor chamber inward surface in a range from the rotor chamber front end surface to the rotor chamber rear end surface,
• an inner contacting surface winch contacts, from outside, the rotor chamber outward surface in a range from the rotor chamber front end surface to the rotor chamber rear end surface,
• a first sealing surface, which connects the outer contact surface and the inner contact surface to each other and seals a first end in the circumferential direction of the cradle window, and
• a second sealing surface, which connects the outer contact surface and the inner contact surface to each other and seals a second end in the circumferential direction of the cradle window,
• wherein the housing includes:
• an outer block that forms the rotor chamber inward surface,
• an inner block, which is arranged inside the outer block and forms the rotor chamber outward surface and wherein the inner block includes a suction port and a discharge port, which communicate with the compression chambers.