PISTON FOR A COMPRESSOR AND PISTON-TYPE COMPRESSOR

摘要

A piston (11) in a compressor reciprocates between a top dead centre and a bottom dead centre in a cylinder bore (2a) via a driving body (9) mounted on a rotating shaft (6) in a crank chamber (5) in association with the rotation of the rotating shaft (6). The piston has an external circumferential surface that is in sliding contact with an internal circumferential surface of the cylinder bore (2a). Grooves (17; 44; 46) extending in the axial direction (S) of the piston (11) are formed in the external circumferential surface of the piston (11). Lubricant adhering to the internal circumferential surface of the cylinder bore (2a) is collected into the grooves (17; 44; 46) in association with the reciprocating movement of the piston (11), and when the grooves (17; 44; 46) are exposed from the inside of the cylinder bore (2a) to the inside of the crank chamber (5), lubricant in the grooves (17; 44; 46) is supplied into the crank chamber (5). The driving body (9) and the like in the crank chamber (5) are lubricated by means of this lubricant. <IMAGE>