Filter with variable cross-section axial seal

This application is related to and claims priority to U.S. Provisional Patent Application No. 62/266,219, entitled “FILTER WITH VARIABLE CROSS-SECTION AXIAL SEAL,” by Tofsland, filed on Dec. 11, 2015, the contents of which are herein incorporated by reference in their entirety and for all purposes.

The present application relates to filtration systems.

Internal combustion engines generally combust a mixture of fuel (e.g., gasoline, diesel, natural gas, etc.) and air. Prior to entering the engine, intake air is typically passed through a filter element to remove contaminants (e.g., particulates, dust, water, etc.) from the intake air prior to delivery to the engine. The filter elements require periodic replacement, as the filter media of the filter elements captures and removes the contaminants from the fluids passing through the filter media. In some cases, unauthorized or non-genuine replacement filter elements may be installed in the filtration systems during servicing operations. The unauthorized and non-genuine replacement filter elements may be of inferior quality to genuine, authorized filter elements. Thus, the use of unauthorized or non-genuine replacement filter elements may cause damage to the engine by allowing contaminants past the filter element.

To prevent the use of unauthorized filter elements, some filtration systems include variations in the filter element seal member, such as key elements and surface disruptors, that permit only authorized replacement filter cartridges to be installed in the filtration systems. However, these surface disruptors and key elements create complex sealing surfaces that can have weak seals because the surface disruptors do not allow the compression of the entire seal along the length of the seal member. The weak seals may allow for bypass of the filter element by the fluid (e.g., air) being filtered.

Various example embodiments relate to filtration systems having an air filter with a variable cross-section axial seal member. One such filtration system includes a housing defining a central compartment therein. The housing includes an outlet and a housing sealing surface. The housing sealing surface is non-planar. The filtration system includes a cover removably coupled to the housing. The cover includes an inlet and a cover sealing surface. The filtration system further includes a filter element positioned within the central compartment of the housing. The filter element includes filter media and a seal member coupled to the filter media and circumscribing at least a portion of the filter media. The seal member has a first sealing surface and a second sealing surface. The seal member has a variable cross-section such that a distance between the first sealing surface and the second sealing surface varies along at least a portion of the seal member. The variable cross-section is complementary to the housing sealing surface and the cover sealing surface such that the seal member forms an axial seal between the housing and the cover when the filter element is installed in the air filtration system.

Another example embodiment relates to a filter element. The filter element includes filter media and a seal member coupled to the filter media and circumscribing at least a portion of the filter media. The seal member comprises a first sealing surface and a second sealing surface. The seal member has a variable cross-section such that a distance between the first sealing surface and the second sealing surface varies along at least a portion of the seal member.

These and other features, together with the organization and manner of operation thereof, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like elements have like numerals throughout the several drawings described below.

Referring to the figures generally, filtration systems having filter elements having an axial seal member with a variable cross-section are described. The variable cross-section is matched by the non-planar sealing surfaces of the housing and housing cover that receive the filter elements. The non-planar sealing surfaces of the housing and the housing cover prevent proper filtration system function when an unauthorized replacement filter element having a flat axial seal member is installed in the housing.

Referring to, an exploded view of a filtration systemis shown according to an example embodiment. In some arrangements, the filtration systemis an air filtration system. The filtration systemincludes a housing, a filter element, and a cover. The coverincludes an inlet. The housingincludes an outlet. The filter elementincludes filter mediaand a seal member. The filter mediamay include any of pleated media, corrugated media, tetrahedral media, or variations thereof. U.S. Pat. No. 8,397,920, entitled “PLEATED FILTER ELEMENT WITH TAPERING BEND LINES,” by Moy et al., filed on Oct. 14, 2011, and issued on Mar. 19, 2013, assigned to Cummins Filtration IP Inc., which is incorporated by reference in its entirety and for all purposes, describes a tetrahedral filter media. Some configurations of tetrahedral filter media include a plurality of inlet tetrahedron flow channels and a plurality of outlet tetrahedron flow channels. The inlet tetrahedron merge in a central portion of the filter material, thereby allowing axial cross-flow of air between the inlet tetrahedron channels prior to the air passing through the filter media. Such an arrangement provides for additional dust loading on the upstream side of the media, which increases filter capacity. Specific arrangements of such tetrahedral filter media are further described in U.S. Pat. No. 8,397,920.

Although the filter mediais shown inas a rectangular block having a rectangular cross-sectional shape, the filter mediacan be arranged in other shapes. For example, the filter mediacan be arranged as a cylindrical filter block having a circular cross-sectional shape, as a wound filter block (e.g., as described below with respect to), as an oval filter block having an oval cross-sectional shape, as a panel, as a race-track shape, or the like.

When the filtration systemis in the assembled state, the filter elementis positioned within a central compartment of the housing. The seal membercontacts the housing sealing surface. The coveris removably coupled to the housing (e.g., by fasteners). As the coveris secured to the housing, the cover sealing surfacecontacts the seal memberand compresses the seal memberbetween the housingand the coverto form an axial seal. The arrangement of the seal memberis described in further detail below with respect to.

Generally, when the filtration systemis assembled, the filtration systemfilters air and provides the filtered air to a device, such as an internal combustion engine. The filtration systemreceives air to be filtered through the inlet. The air passes from the inlet, into the cover, and through the filter mediaof the filter element. As the air passes through the filter media, the filter mediaremoves contaminants (e.g., dirt, dust, moisture, etc.) contained in the air. The filtered air then passes through the housingand out the outlet. As the filter elementfilters the air, the filter mediacaptures the contaminants. Accordingly, the filter elementrequires periodic replacement as the filter mediareaches capacity.

Referring to, various views of the filter elementare shown. As shown best in the perspective view of the filter element() and the top view (), the filter mediais arranged as a filter block. The filter mediaincludes an inlet facedefining a dirty side of the filter elementand an outlet face(opposite the inlet face; shown best in) defining a clean side of the filter element. The seal memberis coupled to and circumscribes at least a portion of an overall longitudinal length (i.e., a perimeter wall) of the filter media. The seal memberis positioned between the inlet faceand the outlet face. In some arrangements, the seal memberis adjacent to the inlet face. As shown in, in some arrangements the seal memberis substantially rectangular in shape when viewed from the top perspective. In such arrangements and similar arrangements, the seal memberincludes two short sides and two long sides.

As shown best in, the seal memberincludes a first sealing surfaceand a second sealing surface. The seal memberhas a variable cross-section. Accordingly, the distance between the first sealing surfaceand the second sealing surfacevaries along at least a portion of the seal member. In arrangements where the seal memberis substantially rectangular in shape when viewed from the top perspective, the variable cross-section is caused by the arc-shape of the first and second sealing surfacesand. In arrangements where the seal memberis substantially rectangular in shape, for example, the arc-shaped sealing surfacesandmay be only along one of the four sides, only along the two long sides, only along the two short sides, or along one of the long sides and one of the short sides.

Referring to, the arc-shape of the first and second sealing surfacesandis shown in greater detail. The arc-shaped profile of the first and second sealing surfacesandextends from a first endof the seal member to a second endof the seal member. The arc-shaped profile comprises a continuous curve between the first endand the second end. The continuous curve is a convex curve. In some arrangements, the continuous curve of the arc-shaped profile is symmetrical about a center axisof the filter element. In such arrangements, the cross-section of the seal memberis greatest at the center axisand smallest at the first endand the second end. Each of the first and second sealing surfacesis elevated at the center axisby a heightwith respect to the first and second endsand. The heightis significantly smaller than a span distancebetween the first endand the second end. In some arrangements, the ratio of the span distanceto the heightis approximately 100:1. In further arrangements, the ratio of the span distanceto the heightis 102:1. In additional arrangements, the ratio of the span distanceto the heightis greater than 10:1. In still further arrangements, the ratio of the span distanceto the heightis greater than 50:1. The resulting arc formed by the continuous curve is a slight convex arc. The slight convex arc advantageously permits greater compression of the center of the seal member(e.g., in the area of the central axis) to compensate for potential flex or warping of the housing sealing surfaceof the housingand the cover sealing surfaceof the cover. Additionally, the relatively small amplitude maintains a majority of the sealing force in the axial direction thereby creating a strong axial seal.

shows a side view of the housingand the coverforming a seal with the seal member.shows a close-up view of section A of.shows a close-up view of section B of. As shown in, when the filter elementis placed in the housingand secured in place with the cover, the housing sealing surfaceand the cover sealing surfaceform an axial seal with the seal member. The housing sealing surfaceand the cover sealing surfaceare non-planar and arced such that the housing sealing surfaceand the cover sealing surfaceare complementary with the variable cross-section of the seal member. The seal memberis compressed between the housing sealing surfaceand the cover sealing surface. In some arrangements, the amount of compression at the center portionof the seal member(as emphasized in area B and shown in) is 1.0 mm. In such arrangements, the amount of compression of at the first endand the secondmay be less than 1.0 mm.

If an unauthorized replacement filter element having a flat axial seal member (e.g., an axial seal member that does not include the arc-shaped profile of the seal member), the housingand the coverwill not form a proper seal against the flat axial seal member. As noted above, the housing sealing surfaceand the cover sealing surfaceare non-planar and arced such that the housing sealing surfaceand the cover sealing surfaceare complementary with the variable cross-section of the seal member. Since the housing sealing surfaceof the housingand the cover sealing surfaceof the coverare arced to form a proper seal with the seal member(as discussed above with respect to), a first gap will exist between the housing sealing surfaceand the flat axial seal member, and a second gap will exist between the cover sealing surfaceand the flat axial seal member. The first and second gaps would provide bypass flow paths around the unauthorized replacement filter element thereby drastically reducing the efficiency of the filtration system.

Referring to, a close-up side view of a filtration systemis shown according to an example embodiment. The filtration systemis substantially similar to the filtration system. Accordingly, like numbering is used to designate similar components. The primary difference between the filtration systemand the filtration systemis that the seal memberof the filtration systemhas a different cross-section than the seal memberof the filtration system. The seal memberincludes a first sealing surfaceand a second sealing surface. Similar to the seal member, the seal memberhas a variable cross-section. Accordingly, the distance between the first sealing surfaceand the second sealing surfacevaries along at least a portion of the seal member. Unlike the seal member, only one of the first sealing surfaceand the second sealing surfaceis non-planar and has an arc-shaped profile caused by a continuous convex curve between the first and second ends of the seal member(e.g., as described above with respect to the arc-shaped profile of the seal member), while the other of the first sealing surfaceand the second sealing surfaceis flat or planar. As shown in, the first sealing surfaceis flat, and the second sealing surfaceis arced in a similar manner as described above with respect to either the first or second sealing surfacesorof the seal member. Accordingly, the cover sealing surfaceof the coveris flat to form a proper seal with the first sealing surface.

Referring to, views of a filter elementare shown according to an example embodiment. The filter elementis a cylindrical filter element having filter mediasurrounding a central core. The filter mediamay include any of pleated media, corrugated media, tetrahedral media, or variations thereof. In some arrangements, the filter mediais wound around the core. The filter elementincludes a seal member. When the filter elementis positioned in a filtration system housing, the seal memberis compressed between the housing and a housing cover (e.g., in a similar manner as described above with respect to the filter elementof the filtration system). The filter mediaincludes an inlet faceand an outlet face. When the filter elementis installed within the housing and the filtration system is activated, air to be filtered passes through the filter mediafrom the inlet faceand out of the outlet face.

The seal memberis coupled to and circumscribes an axial wall of the filter media. The seal memberis positioned between the inlet faceand the outlet face. In some arrangements, the seal memberis adjacent to the inlet face. The seal memberis substantially ring-shaped when viewed from the top perspective. As shown best in, the seal memberincludes a first sealing surfaceand a second sealing surface. The seal memberdoes not have a uniform cross-section. Accordingly, the distance between the first sealing surfaceand the second sealing surfacevaries along at least a portion of the circumference of the seal member. Each of the first sealing surfaceand the second sealing surfaceare non-planar. Both the first sealing surfaceand the second sealing surfacehave a continuous wave profile (as shown in). In the arrangement of, the continuous wave profiles of the first sealing surfaceand the second sealing surfaceare aligned such that the seal memberhas thick portionsand thin portions. In other arrangements, the continuous wave profiles of the first and second sealing surfacesandare offset such that the seal memberhas a substantially uniform thickness around the circumference.

In some arrangements, the continuous wave profile is a sinusoidal wave pattern. The amplitude distance of the sinusoidal wave pattern is substantially smaller than the period distance (i.e., the distance between successive peaks in the sinusoidal wave pattern). In some arrangements, the ratio of the period distance to the amplitude distance is approximately 100:1. In further arrangements, the ratio of the period distance to the amplitude distance is 102:1. In additional arrangements, the ratio of the period distance to the amplitude distance is greater than 10:1. In still further arrangements, the ratio of the period distance to the amplitude distance is greater than 50:1. The sinusoidal wave pattern is a wave pattern having a relatively small amplitude. The relatively small amplitude advantageously permits greater compression of the of the seal memberat the peak portionsto compensate for potential flex or warping of the housing sealing surface of the housing and the cover sealing surface of the cover. Additionally, the relatively small amplitude maintains a majority of the sealing force in the axial direction thereby creating a strong axial seal.

In order for the filter elementto form a proper seal with the housing and the housing cover, the sealing surfaces of the housing and the housing cover have a matching sinusoidal wave pattern. If an unauthorized replacement filter element having a flat axial seal member (e.g., an axial seal member that does not include the arc-shaped profile of the seal member), the housing and the cover will not form a proper seal against the flat axial seal member. Since the housing sealing surface of the housing and the cover sealing surface of the cover have waved sealing surfaces to form a proper axial seal with the seal member, gaps will exist between the housing sealing surface, the cover sealing surface, and the flat axial seal member. The gaps would provide bypass flow paths around the unauthorized replacement filter element thereby drastically reducing the efficiency of the filtration system.

Referring to, a flow diagram of a methodof replacing a filter element in a filtration system (e.g., filtration system) is shown according to an example embodiment. The methodbegins when a filter element is removed from the filtration system at. The filter element is removed by a technician or another individual servicing the filtration system. To remove the filter cartridge, a filtration system cover (e.g., cover) is removed from the housing (e.g., housing) to provide access to the installed filter cartridge. After the filter cartridge is removed at, a replacement filter cartridge (e.g., filter element) is provided at. The filter elementincludes filter media and an axial seal member (e.g., seal member) of the type discussed above. The axial seal member includes at least one sealing surface having an arc-shaped profile comprising a continuous curve between a first and second end of the seal member. The arc-shaped profile of the axial seal member substantially matches a mating arc-shaped profile in the cover and/or housing sealing surfaces.

The replacement filter element is installed at. The replacement filter element is inserted into the housing. When the replacement filter element is inserted into the housing a first sealing surface of the axial seal member contacts a housing sealing surface. The replacement filter element may be of the type discussed above with regard to the filter media and the axial seal member. The cover is secured to the housing at. When the cover is secured to the housing, a second sealing surface of the axial seal member contacts a cover sealing surface of the cover. The cover may be secured to the housing via a clamp, a fastener, a snap-fit connection, or the like. As the cover is secured to the housing, the seal member is compressed between the housing sealing surface and the cover sealing surface, forming an axial seal.

It should be noted that any use of the term “example” herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representations, and/or illustrations of possible embodiments (and such term is not intended to connote that such embodiments are necessarily extraordinary or superlative examples).

The terms “coupled” and the like as used herein mean the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another.

References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below,” etc.) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other example embodiments, and that such variations are intended to be encompassed by the present disclosure.

The term “approximately” when used with respect to values means plus or minus five percent of the associated value.

It is important to note that the construction and arrangement of the various example embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Additionally, features from particular embodiments may be combined with features from other embodiments as would be understood by one of ordinary skill in the art. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various example embodiments without departing from the scope of the present invention.