A filter element has a filter medium with a plurality of successive folds arranged in a longitudinal direction from a first transverse side of the filter medium to a second transverse side of the filter medium. A fold height of the successive folds continuously decreases in the longitudinal direction. A fold width of the successive folds continuously decreases in the longitudinal direction. A filter device such as an air filter is provided with such a filter element.

Filter cartridges including tubular filter media having ovate cross-sections and filter systems using the ovate tubular filter cartridges are described herein. The inner perimeters of the ovate cross-sections of one or more of the filter cartridges may be asymmetric, i.e., the inner perimeters of the cross-sections of the tubular filter media in the filter cartridges may have no lines about which they are symmetric. The inner perimeters of the ovate cross-sections of the tubular filter media in one or more of the filter cartridges may have only one line of symmetry.

A filter system includes a housing comprising a first housing part and a second housing part, a fluid inlet formed in the first housing part, a fluid outlet formed in the second housing part, and a filter element being accommodated in the housing, and comprising a filter body with a filter medium enclosed by a circumferential frame element, and structure elements protruding from a circumference of the filter element, the structure elements comprising grooves respectively in circumference walls of the structure elements. The first housing part comprises a receiving part for receiving the filter element, the receiving part comprising counter elements respectively corresponding to the structure elements, and the counter elements being breakthroughs that are arranged circumferentially on and formed through a wall of the receiving part. The grooves included in the structure elements are for receiving edges of the breakthroughs of the counter elements.

Provided is a filter assembly including: a first filter medium (110) that is bent so that high-point portions (111) and low-point portions (113) defined based on a vertical plane with respect to a first direction are alternately and repeatedly formed in a second direction perpendicular to the first direction; a first filter frame (130) configured to accommodate the first filter medium (110) and to fix an edge side of the first filter medium (110); a second filter medium (120) that is bent so that the low-point portions (121) and the high-point portions (123) defined based on the vertical plane with respect to the first direction are alternately and repeatedly formed in the second direction; and a second filter frame (140) configured to accommodate the second filter medium (120) and to fix an edge side of the second filter medium (120), wherein at least a portion of the high-point portions repeatedly formed in the first filter medium (110) have different heights from those of the other high-point portions, and at least a portion of the low-point portions repeatedly formed in the second filter medium (120) have different heights from those of the other low-point portions, and the first and second filter media (110, 120) are bent in such a way that a first filter medium high-point envelope (111a) connecting high points of the first filter medium (110) and a second filter medium low-point envelope (121a) connecting low points of the second filter medium (120) correspond to each other when viewed from a cross-section including the first direction and the second direction, and the first and second filter frames (130, 140) are combined with each other so that the first filter medium high-point envelope (111a) and the second filter medium low-point envelope (121a) face each other.

A fluid filter has a filter housing with inlet opening for fluid to be cleaned and outlet opening for cleaned fluid. A filter element arranged in an element receptacle of the filter housing separates inlet opening from outlet opening. The filter housing has a housing body with an installation opening to the element receptacle, through which the filter element in an installation direction is introduced into the element receptacle. The filter housing has a housing cover for closing the installation opening. The installation opening is arranged in a transverse side of the housing body that is lateral relative to the housing axis. The filter housing has a sealing surface, surrounding the housing axis at least partially circumferentially, for contacting a seal of the filter element. The filter element has a seal support device for the seal and the filter housing has a pressing device for the seal support device.

The invention pertains to an air filter element (100) comprising: a filter medium pack (110) comprising a filter medium, said filter medium pack having an optionally substantially planar first side (111) and an optionally substantially planar second side (112), said first side (111) and second side optionally being parallel (112); and a guiding rim (120) comprising a sealing surface having at least a radially oriented component, arranged on at least one of said first side (111) and said second side (112); wherein a circumference of the or each guiding rim comprises at least one convex portion and at least one concave portion; and wherein a contour of said filter medium pack (110) corresponds to said convex portion of said guiding rim and at least part of said concave portion. The invention also pertains to a method for producing an air filter element.

A filter element for insertion into a housing of a filter system. The filter element includes a filter medium pack and a seal receiver. The filter medium pack has an outer circumferential face extending between a first outer axial face and a second outer axial face, opposite the first outer axial face. The filter element further includes a seal receiver sealingly attached to the filter medium pack. The seal receiver includes a closed-loop surface suitable for receiving a removable circumferential seal member, and wherein the closed-loop surface forms a contour shape with single-fold rotational symmetry. A seal assembly including a filter element and a seal carrier is also presented.

A reusable air filter and methods are provided for filtering air being conducted to an air intake of an internal combustion engine. The reusable air filter comprises a filter medium configured to pass an airstream and entrap particulates flowing within the airstream. The filter medium is comprised of cotton gauze disposed in a sinusoidal arrangement that provides a filtration surface area that is larger than a perimeter area of the filter medium. An end cap and base may be configured to retain the filter medium therebetween. The base provides an interface between the air filter and an air inlet of the engine. The filter medium may be disposed in a flat, panel shape that is bordered by a supportive tray. Support rods may be embedded within the tray to prevent bowing of the tray due to air pressure when coupled with an air box of the engine.

A media pack for including in a filter cartridge of an air filter arrangement, is provided. A variety of configurations for the media pack are described and shown, an example shown being trapezoidal. Filter cartridges including such media packs, air cleaner assemblies and equipment systems are described. Also methods of use assembly are described.

Various example embodiments relate to a filtration system. The filtration system comprises a housing having a first housing end and a second housing end. The housing defines a central compartment therein. The housing comprises a first alignment portion disposed on the first housing end. The filtration system further comprises a filter element positioned within the central compartment of the housing. The filter element has a first filter end and a second filter end. The filter element comprises filter media and a second alignment portion disposed on the first filter end. The second alignment portion is complementary to the first alignment portion. The installation of the filter element within the housing causes the first alignment surface and the second alignment surface to align to provide for engagement of a radial seal between the filter element and the housing.