| 摘要 |
PURPOSE:To circulate leaked lubricating oil to a suction room so as to improve pumping efficiency by dually providing the pump room side and the outer side with a seal being formed by the cover-attaching face of a casing and the inner face of the cover being in close contact with each other. CONSTITUTION:An oil pump 1 for an internal combustion engine has a pump casing 5 and a cover 24 in close contact with the casing. The contact face between the casing 5 and the cover 24 allows a pump room to be sealed. A cover-attaching face 22 is dually formed so that it is separated into a pump room side portion 22a enclosing a circular recess 6 and the outer portion 22b. Leaked lubricating oil, instead of being allowed to return to an oil pan, is directly circulated to a suction room via a passage 26 that circulates lubricating oil under excessive pressure to the suction room 10. Hence, reduced channel resistance owing to a strainer and a piping results in decrease in a negative pressure within the suction room and leads to the improvement of pumping efficiency. |
