Patent ID: 7232034

Claim:
An oil filter comprising: a housing main body having an inlet passage and an outlet passage; a cover detachably attached to the housing main body and having a recessed portion that opens toward a housing main body side; a partition member disposed in the recessed portion of the cover so as to be movable into and out of the recessed portion and partitioning a space between the cover and the housing main body into a filter chamber on a housing main body side and an oil suction chamber on a bottom side of the cover; a seal member interposed between the partition member and the cover to provide a seal therebetween; a biasing unit for urging the partition member in a direction to increase the volume of the oil suction chamber; a filter element disposed in the filter chamber for filtrating oil introduced thereinto; and a communication passage for providing communication between the oil suction chamber and the oil filter chamber; wherein when the cover is attached to the housing main body, the partition member is pushed down into the recessed portion of the cover against the bias of the biasing unit; and wherein the biasing unit holds the partition member pressed against the housing main body so that the volume of the oil suction chamber increases as the cover is moved increasingly away from the housing main body upon removal of the cover.