Vane compressor

A vane compressor comprising:

• a cylinder including a cylindrical inner circumferential surface that defines a hole having opposite openings;
• a cylinder head that covers one of the openings;
• a frame that covers another one of the openings;
• a cylindrical rotor portion configured to rotate about a rotation axis displaced from a central axis of the inner circumferential surface inside the cylinder;
• a rotating shaft portion configured to transmit a rotational force to the rotor portion;
• and
• a vane disposed inside the rotor portion, held rotatably about a center of the cylinder inner circumferential surface of the cylinder, and partitioning a compression space formed between the cylinder and the rotor portion into at least a suction space and a discharge space;
• wherein each of the frame and the cylinder head includes a recess or a ring-shaped groove in an end face near the cylinder, the recess or the ring-shaped groove having an outer circumferential surface concentric with the inner circumferential surface of the cylinder,
• a vane aligner having a partial ring-shape and configured to support the vane is provided, the vane aligner being capable of freely sliding and rotating along the outer circumferential surface, and integrally attached to the vane or integrally formed with the vane so as to keep a gap between a tip of the vane and the inner circumferential surface of the cylinder,
• a first discharge port communicating with the compression space and a second discharge port communicating with the compression space are provided, the first discharge port configured to allow gas compressed in the compression space to be discharged therethrough, the second discharge port being provided at a location upstream from the first discharge port in a compression stroke, and
• the second discharge port includes an opening portion to the compression space, the opening portion having a width equal to or smaller than a width of the vane.