| 摘要 |
PURPOSE:To effect a satisfactory lubrication with no use of a pump, etc., by opening and closing either one of suction side or discharge side check-valves which allows oil to flow only from an oil sump chamber to the crank chamber side or the oil passage side, in association with variations in positive and negative pressures of the crank chamber. CONSTITUTION:When a piston 14 is, for example, raised so that the pressure in a crank chamber 12 becomes negative, a discharge side check valve 32 is closed while a suction side check valve 26 is opened. Then, oil flows into the crank chamber 12 from a mission chamber 19 serving as an oil sump chamber through two suction side communication holes 23, 24. Further, oil fed from the above-mentioned hole 24 flows through a crank pin 13b to lubricate a bearing 30 between a piston rod 14a and a connecting rod 15. Further, oil fed from the above-mentioned two communication holes 23, 24 lubricates the piston slide surface of the cylinder 11, and the like, and further, oil which has been scraped off by the piston 14 lubricates a bearing 13a which supports a crank shaft 13. |
