| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce blowby gas so as to prevent the lowering of a compressive efficiency by suppressing the increase of a clearance between a piston and a cylinder bore when temperature is raised. SOLUTION: A steel flame sprayed film 70 on the peripheral surface of a piston 7 is divided into a plurality of film parts 71 in a piston peripheral direction, thereby the expansion of the piston 7 may not be disturbed by the flame sprayed film 70 when temperature is raised. Also, both ends 71a, 71a of the piston peripheral direction of the plurality of film parts 71 are respectively formed into the shape of the teeth of a comb, and the adjacent film parts 71 are engaged with each other through a predetermined clearance 72, thereby the clearance 72 between the film parts 71 can be formed into a meandering shape. Hereby, refrigerant gas (blowby gas) is hardly degassed from a compression chamber 29 on one side of the piston 7 to the other end side of the piston 7, and also oil is separated, then the separated oil is supplied between the peripheral surface of the piston 7 and the inner circumferential surface of a cylinder bore 6.</p> |
