Oil filter with inner and outer coaxial filter elements

摘要

A filter assembly for an internal combustion engine includes inner and outer coaxial filter elements disposed in a spin-on canister which is detachably secured to a mounting adaptor. Oil from the crankcase is filtered by the outer filter element and a substantial volume of the filtered oil flows to the primary lubricating circuit of the engine. A small percentage of the filtered oil is subjected to further filtration by the inner filter element and is returned directly to the crankcase. A single gasket including a sealing ring and a concentrically disposed tubular fitting attached to the sealing ring by support legs is positioned to prevent commingling of the oil from the crankcase with oil filtered by the outer filter element and to prevent the oil filtered by the outer filter element from commingling with oil filtered by the inner filter element. In addition, the inner filter element is provided with a warm-up orifice to insure oil flow regardless of the condition of the inner and outer filter elements.