| 摘要 |
PURPOSE:To improve the returning of oil from a bottom plate constructionally in a shape easily accumulated with the oil, by circulating air in an oil pan via the bottom plate of a crank chamber and forcibly returning the oil accumulated on the bottom plate through this circulative air flow. CONSTITUTION:A check valve 26 in a bottom plate 20 of a crank chamber is opened by negative pressure of pulsating air in the crank chamber 22a to suck air from a rocker chamber 11 to the chamber 22a via an oil pan 3 and hole 27, and this sucking action forcibly returns oil accumulated in a bottom part of the rocker chamber directly to the oil pan 3 further the oil is dropped by its own weight and accumulated. Then another check valve 29 in the plate 20 of the crank chamber is opened to discharge air in the chamber 22a to the oil pan 3 via a hole 30. While a check valve 23 is also opened to circulate air flowing through in the chamber 11, and the air discharged to the oil pan 3 flows in through the hole 27 to enter the crank chamber at negative pulsating pressure, and this action is performed in the same timing as oil returning from rocker chambers 11, 11' to increase a forcible returning amount of the oil. |
