Internal combustion engine system and compressor

A compressor comprising:

• a cylinder including a suction port and a discharge port;
• a piston accommodated in the cylinder and defining a compression chamber facing the suction port and the discharge port;
• a rod projecting from the piston;
• a cam that reciprocates the rod;
• a camshaft that rotates the cam;
• and
• a ring that covers an outer peripheral surface of the cam and is rotatable relative to the cam, wherein:
• the outer peripheral surface of the cam includes a true circular shape;
• the camshaft is eccentrically connected to the cam;
• and
• the cam pushes the rod through the ring.

A compressor comprising:

• a cylinder including a suction port and a discharge port;
• a piston accommodated in the cylinder and defining a compression chamber facing the suction port and the discharge port;
• a rod projecting from the piston;
• a first rod seal located between an outer peripheral surface of the rod and an inner peripheral surface of the cylinder;
• and
• a recompression chamber located between the piston and the first rod seal in an axial direction of the cylinder, wherein:
• the recompression chamber is defined by the outer peripheral surface of the rod and the inner peripheral surface of the cylinder;
• a volume of the recompression chamber decreases by backward movement of the piston;
• and
• the cylinder includes an outflow port that is in fluid communication with the recompression chamber.