Abstract: The present invention relates to a filtering device, which comprises a base plate (12) having a threaded center hole (122); a filter housing (11) having a cap-shaped body coupleable to the base plate; an anti-drainback valve (15) having a valve hole (151) defined in the center portion thereof arranged on the base plate (12), where the valve hole (151) correspondingly aligns with the threaded center hole (122) of the base plate (12); a filter assembly (14) having a filter hole (1411) abutting on the anti-drainback valve (15), where the filter hole (1411) aligns with the valve hole (151) of the anti-drainback valve (15); and a bypass valve (13) having a central plate portion (132) and a pair of extending wing portions (131) pressingly arranged between the inner surface of the filter housing and the filter assembly. The separately removable housing (11) provides easy assembly and enables simple filter media replacement.

Abstract: The instant disclosure relates to a double-layer filter structure disposed in an oil filter. The double-layer filter structure includes two individual filter media for removing impurities of different sizes in the engine oil. The double-layer filter structure includes a first filter medium and a second filter medium. The first filter medium has a plurality of wave-shaped and annularly arranged first folding portions. Similarly, the second filter medium has a plurality of wave-shaped and annularly arranged second folding portions. Each of the first folding portions has a mating portion retained by the second folding portions correspondingly.

Abstract: The present invention relates to a filtering device, which comprises a base plate (12) having a threaded center hole (122); a filter housing (11) having a cap-shaped body coupleable to the base plate; an anti-drainback valve (15) having a valve hole (151) defined in the center portion thereof arranged on the base plate (12), where the valve hole (151) correspondingly aligns with the threaded center hole (122) of the base plate (12); a filter assembly (14) having a filter hole (1411) abutting on the anti-drainback valve (15), where the filter hole (1411) aligns with the valve hole (151) of the anti-drainback valve (15); and a bypass valve (13) having a central plate portion (132) and a pair of extending wing portions (131) pressingly arranged between the inner surface of the filter housing and the filter assembly. The separately removable housing (11) provides easy assembly and enables simple filter media replacement.