<p>An oil supply hole (60) connecting from the inner surface (32b) of a piston (32) to a cylindrical fitting section (32a) is formed. This causes a predetermined zone of an oil groove (45) to communicate with the oil supply hole (60) when a crankshaft (31) is rotated and allows oil which is present in the oil groove (45) to pass through the oil supply hole (60) and be supplied to a rocking section formed by the cylindrical fitting section (32a) and an insertion section (33a) at the tip of a vane (33). As a result, sliding conditions of the rocking section are further improved and sealing properties of the rocking section are also improved. This further suppresses a leakage of gas from a high-pressure compression chamber (39) to a low-pressure suction chamber through a gap of the rocking section.</p>
