Patent Description:
Internal combustion engines use various fluids during operation. For example, fuel (e.g., diesel, gasoline, natural gas, etc.) is used to run the engine. Air may be mixed with the fuel to produce an air-fuel mixture, which is then used by the engine to run under stoichiometric or lean conditions. Furthermore, one or more lubricants may be provided to the engine to lubricate various parts of the engine (e.g., piston cylinder, crank shaft, bearings, gears, valves, cams, etc.). These fluids may become contaminated with particulate matter (e.g., carbon, dust, metal particles, etc.) which may damage the various parts of the engine if not removed from the fluid. To remove such particulate matter or other contaminants, the fluid is generally passed through a filter assembly (e.g., a fuel filter, a lubricant filter, an air filter, a water filter assembly, etc.) including a filter element structured to remove the particulate matter from the fluid prior to delivering the fluid. Many mounts or structures in which the filter assemblies are installed may be space constrained and have unique shapes, and complex filter element shapes may be desired to accommodate the filter element within such mounting structures.

<CIT> discloses features, components and techniques useable for providing air cleaner arrangements. Many of the features relate to an axial seal arrangement provided on a filter cartridge. A typical filter cartridge, for use with these features, is a filter cartridge having opposite flow ends. Example media arrangements that fit this characterization are described. Seal arrangements provided with an axial housing sealing engagement surface are shown. A seal arrangement is provided with variations therein. These variations can be in both of an outer peripheral edge surface and a housing seal engagement surface. Also, air cleaner assemblies are provided. Further, air cleaner housings are described, with selected, preferred features for engagement with filter cartridges.

Embodiments described herein relate generally to filter assemblies including multilayered or wrapped filter elements having a polymeric layer disposed on sidewalls of a filter media pack of the filter element to form a housing thereof, having indentations defined in the filter media pack, or defining non-circular cross-sections.

Aspects of the present invention are defined by appended independent claims.

Described herein is a filter assembly that comprises a filter element. The filter element comprises a filter media pack comprising a plurality of filter media layers stacked on top of each other to form the filter media pack, the filter media pack having an inlet surface being at an inlet portion of the filter media pack, and an outlet surface being at an outlet portion of the filter media pack. An outlet flange is coupled to the outlet portion of the filter media pack.

Also described herein is a filter element that comprises a core having a non-circular core cross-sectional shape; and a filter media pack comprising a plurality of filter media layers stacked on an outer periphery of the core such that the filter media pack has a filter media pack cross-sectional shape that corresponds to the core cross-sectional shape.

Also described herein is a filter element that comprises a core, a filter media pack comprising a plurality of filter media layers stacked on an outer periphery of the core, and a filter housing. The filter housing comprises a housing portion defining an internal volume within which the filter media pack is disposed, an outer radial surface of the filter media pack bonded to an inner radial surface of the housing portion, and a coupling portion fluidly coupled to the housing portion distal from the filter media pack, the coupling portion defining an opening for allowing fluid to flow therethrough, the coupling portion configured to be coupled to a conduit.

Also described herein is a filter element that comprises a filter media pack comprising a plurality of filter media layers stacked on top of each other to form the filter media pack. The filter media pack has an inlet surface at an inlet portion of the filter media pack, and an outlet surface at an outlet portion of the filter media pack.

In an embodiment of the present invention, a filter element, comprises a core having a non-circular core cross-sectional shape. A filter media pack comprises a filter media layer wrapped around an outer periphery of the core such that the filter media pack has a filter media pack cross-sectional shape that corresponds to the non-circular core cross-sectional shape.

It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the subject matter disclosed herein.

The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several implementations in accordance with the disclosure and are therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings.

Reference is made to the accompanying drawings throughout the following detailed description. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative implementations described in the detailed description, drawings, and claims are not meant to be limiting. Other implementations may be utilized, and other changes may be made, without departing from the scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and made part of this disclosure.

Embodiments and examples described herein relate generally to filter assemblies including multilayered or wrapped filter elements having a polymeric layer disposed on sidewalls of a filter media pack of the filter element to form a housing thereof, having indentations defined in the filter media pack, or defining non-circular cross-sections.

Many mounts or structures in which the filter assemblies are installed may be space constrained and have unique shapes, and complex filter element shapes may be desired to accommodate the filter element within such mounting structures. Embodiments and examples of filter elements and filter assemblies described herein may provide one or more benefits including, for example: (<NUM>) allowing formation of complex shaped filter elements that can be installed in complex shaped housing; (<NUM>) disposing a polymeric layer around sidewalls of the filter media pack which serves as a sealing member as well as an integrated housing for the filter media pack; (<NUM>) providing more efficient sealing and reduce pressure drop across filter elements; and (<NUM>) reducing manufacturing costs.

<FIG> is a perspective view, and <FIG> is an exploded view of a filter assembly <NUM>, according to an example. The filter assembly <NUM> may comprise a filter element <NUM>, an outlet flange <NUM> and in some embodiments, may also include an inlet flange <NUM>. <FIG> is a front perspective view of the filter element <NUM> included in the filter assembly <NUM> of <FIG>, according to an embodiment. The filter element <NUM> may be used to filter air, fuel, air/fuel mixtures, water, lubricants, or other fluids. In some embodiments, the filter assembly <NUM> may be used in a vehicle, equipment or power generation system.

The filter element <NUM> includes a multilayered filter media pack <NUM> having an inlet portion <NUM> and an outlet portion <NUM>. Expanding further, the filter media pack <NUM> includes a plurality of filter media layers 122a. As shown in <FIG>, the plurality of filter media layers 122a are stacked on top of each other to form the filter media pack <NUM>. The filter media pack <NUM> comprises a porous material having a predetermined pore size and configured to filter particulate matter from a fluid flowing therethrough so as to produce filtered fluid. The filter media pack <NUM> may include any suitable filter media. In some embodiments, the filter media pack <NUM> may comprise a tetrahedral media, i.e., a filter media including or formed into a tetrahedral shape (e.g., formed into tetrahedral pleats), as described in detail herein. In other embodiments, the filter media pack <NUM> may be formed of fluted media, a straw media, an origami media or any other suitable filter media. While <FIG> shows the filter media pack <NUM> as having a generally rectangular shape, in other embodiments, the filter media pack <NUM> may have any suitable shape, for example, square, polygonal, circular, oval, elliptical, asymmetric, etc..

The filter media pack <NUM> defines an inlet surface <NUM> being at the inlet portion <NUM> configured to receive unfiltered fluid, and an outlet surface <NUM> being at the outlet portion <NUM> configured to expel fluid that has been filtered after passing through the filter media pack <NUM>. A polymeric layer <NUM> is disposed on at least one sidewall of a plurality of sidewalls of the filter media pack <NUM> located generally parallel to a flow path of the filter media pack <NUM>. In particular implementations, the polymeric layer <NUM> is disposed on all outer surfaces of the filter media pack <NUM> except on the inlet portion <NUM> and the outlet portion <NUM>, e.g., except on the inlet surface <NUM> and the outlet surface <NUM>, and adheres to the plurality of sidewalls so as to form a housing of the filter media pack <NUM>. The polymeric layer <NUM> may be coated (e.g., spray coated or dip coated), attached via an adhesive, wrapped around the filter media pack <NUM>, or disposed on the at least one sidewall using any suitable mechanism.

In some embodiments, the polymeric layer <NUM> may include a foam urethane or structural polyurethane that may be spray coat, drop coated or dip coated on the plurality of sidewalls of the filter media pack <NUM>. In various embodiments, the inlet surface <NUM>, the outlet surface <NUM>, and any other mounting surfaces may be masked with a masking layer (e.g., a plastic sheet) before application of the polymeric layer, for example, immersion of the filter media pack <NUM> into a vat of the polymeric material. The polymeric material adheres to and solidifies on the sidewalls, thereby forming the polymeric layer <NUM> surrounding the filter media pack <NUM> so as to form a housing of the filter element <NUM> that has the same cross-section as the cross-section defined by the filter media pack <NUM>. In this manner, complex shapes may be formed that can comply with constrained spaces or complex mounting structures. The masking layers are then removed to expose the inlet surface <NUM> and the outlet surface <NUM>.

In some embodiments, one or more indentations (e.g., a slot, a cavity, a depression, a notch, etc.) may be formed or cut in at least one sidewall of the plurality of sidewalls of filter media pack <NUM>. For example, one or more indentations may be formed in the one or more of the sidewalls of the filter media pack <NUM> transverse to the fluid flow axis, or on the inlet surface <NUM> and/or outlet surface <NUM>. For example, <FIG>, and <FIG> show a semi-circular indentation! <NUM> formed into a sidewall of filter media pack <NUM> located parallel to a flow path defined through the filter media pack <NUM>. In some embodiments, the filter media indentation <NUM> may be formed after the plurality of filter media layers 122a have been stacked to form the filter media pack <NUM> using any suitable means, for example, water jet cutting or laser cutting. In other embodiments, a filter media layer indentation 126a may be formed in each filter media layer 122a before stacking, and the plurality of filter media layers 122a may then be stacked such that each filter media layer indentation 126a is axially aligned with each other to form the filter media indentation <NUM>. The polymeric layer <NUM> is thereafter disposed on the sidewalls of the filter media pack <NUM>. In this manner, asymmetric and complex shapes can be formed, while eliminating the use of a separate housing for the filter element <NUM>.

The inlet flange <NUM> is coupled to the inlet portion <NUM>, and the outlet flange <NUM> is coupled to the outlet portion <NUM>. The inlet flange <NUM> includes an inlet flange base <NUM> positioned in a confronting relationship with the inlet surface <NUM> of the filter media pack <NUM> and defining an inlet flange opening therein. The inlet flange base <NUM> has a cross-section generally corresponding to a transverse cross-section of the filter media pack <NUM>. In some embodiments, the inlet flange base <NUM> may include ridge, ribs, detents or protrusions projecting from the inlet flange base <NUM> towards the inlet surface <NUM> of the filter media pack <NUM>, and may be in contact therewith. An inlet flange peripheral sidewall <NUM> projects from outer edges of the inlet flange base <NUM> towards the filter media pack <NUM> and is disposed around a perimeter of the sidewalls of the filter media pack <NUM> proximate to the inlet surface <NUM>. An inlet conduit <NUM> is fluidly coupled to the inlet flange opening. For example, as shown in <FIG>, the inlet conduit <NUM> has a cross-section that is smaller than a cross-section of the inlet flange opening. In such embodiments, the inlet flange <NUM> further comprises an inlet flange connecting wall <NUM> extending from an outer edge of the inlet conduit <NUM> to a rim <NUM> of the inlet flange opening, i.e., the inlet flange connecting wall <NUM> has a tapered cross-section that expands from the inlet flange <NUM> towards the inlet flange base <NUM>.

Similar to the inlet flange <NUM>, the outlet flange <NUM> includes an outlet flange base <NUM> positioned in a confronting relationship with the outlet surface <NUM> of the filter media pack <NUM> and defining an outlet flange opening <NUM> therein. The outlet flange base <NUM> has a cross-section generally corresponding to a transverse cross-section of the filter media pack <NUM>. In some embodiments, the outlet flange base <NUM> may include ridge, ribs, detents or protrusions projecting from the outlet flange base <NUM> towards the outlet surface <NUM> of the filter media pack <NUM>, and may be in contact therewith. An outlet flange peripheral sidewall <NUM> projects from outer edges of the outlet flange base <NUM> towards the filter media pack <NUM> and is disposed around a perimeter of the sidewalls of the filter media pack <NUM> proximate to the outlet surface <NUM>. An outlet conduit <NUM> is fluidly coupled to the outlet flange opening <NUM>. The outlet conduit <NUM> has a cross-section that is smaller than a cross-section of the outlet flange opening <NUM>, and the outlet flange <NUM> further comprises an outlet flange connecting wall <NUM> extending from an outer edge of the outlet conduit <NUM> to a rim <NUM> of the outlet flange opening <NUM>. In some embodiments, the outlet flange <NUM> is substantially similar to the inlet flange <NUM>.

In various embodiments, the inlet flange <NUM> and the outlet flange <NUM> are secured to the filter element <NUM> via adhesive tape. In other embodiments, the filter media pack <NUM> may be potted into the inlet flange <NUM> and/or outlet flange <NUM>, or hot melted therein. For example, adhesive tape may be wound around the sidewalls of filter element <NUM> proximate to the inlet portion <NUM> and the outlet portion <NUM> such that a portion of the respective adhesive tapes overlap the inlet flange peripheral sidewall <NUM> and the outlet flange peripheral sidewall <NUM>, thereby securing the inlet flange <NUM> and the outlet flange <NUM> to the filter element <NUM>. Thus, sealing may not be used which reduces manufacturing complexity and cost. Furthermore, mounting brackets with straps and/or mounting feet may be used to facilitate mounting of the filter assembly <NUM>.

In some embodiments, the filter media pack <NUM> or any other filter media pack described herein, may comprise a tetrahedral filter media. For example, in particular embodiments, the filter media pack <NUM> may comprise tetrahedral filter media defined by a plurality of tetrahedron channels as described in <CIT>. Expanding further, <FIG> show a filter media <NUM> which can be used to form the filter media pack <NUM> of the filter element <NUM>. The filter media <NUM> has an upstream inlet <NUM> receiving incoming dirty fluid as shown at arrows <NUM>, and having a downstream outlet <NUM> discharging clean filtered fluid as shown at arrows <NUM>. The filter media <NUM> is manipulated along a plurality of bend lines <NUM>. The bend lines extend axially along an axial direction <NUM>, <FIG>, and include a first set of bend lines <NUM> extending from the upstream inlet <NUM> towards the downstream outlet <NUM>, and a second set of bend lines <NUM> extending from the downstream outlet <NUM> axially towards the upstream inlet <NUM>. The filter media <NUM> has a plurality of filter media wall segments <NUM> extending in serpentine manner between the bend lines. The wall segments extend axially and define axial flow channels <NUM> therebetween. The channels <NUM> have a height <NUM> along a transverse direction <NUM>, which transverse direction <NUM> is perpendicular to axial direction <NUM>, <FIG>. The channels <NUM> have a lateral width <NUM> along a lateral direction <NUM>, which lateral direction <NUM> is perpendicular to axial direction <NUM> and perpendicular to transverse direction <NUM>. At least some of the noted bend lines taper in the noted transverse direction as they extend axially in the noted axial direction, to be described.

The wall segments include a first set of wall segments <NUM>, <FIG>, <FIG>, alternately sealed to each other at the upstream inlet <NUM>, e.g. by adhesive <NUM> or the like, to define a first set of channels <NUM> having open upstream ends, and a second set of channels <NUM> interdigitated with the first set of channels and having closed upstream ends. The wall segments include a second set of wall segments <NUM>, <FIG>, <FIG>, alternately sealed to each other at the downstream outlet <NUM>, e.g., by adhesive <NUM> or the like, to define a third set of channels <NUM> having closed downstream ends, and a fourth set of channels <NUM>, <FIG>, having open downstream ends. The first set of bend lines <NUM> includes a first subset of bend lines <NUM> defining the first set of channels <NUM>, and a second subset of bend lines <NUM> defining the second set of channels <NUM>. The second subset of bend lines <NUM> taper in transverse direction <NUM> as they extend from the upstream inlet <NUM> axially towards the downstream outlet <NUM>, <FIG>. The second set of bend lines <NUM> includes a third subset of bend lines <NUM> defining the third set of channels <NUM>, and a fourth subset of bend lines <NUM> defining the fourth set of channels <NUM>. The fourth subset of bend lines <NUM> taper in the transverse direction <NUM> as they extend from the downstream outlet <NUM> axially towards the upstream inlet <NUM>, <FIG>. The second set of channels <NUM> have a decreasing transverse channel height <NUM> along transverse direction <NUM> as the second set of channels <NUM> extend axially along axial direction <NUM> towards the downstream outlet <NUM>. The tapering of the second subset of bend lines <NUM> in the transverse direction <NUM> provides the decreasing transverse channel height <NUM> of the second set of channels <NUM>. The fourth set of channels <NUM> have a decreasing transverse channel height along transverse direction <NUM> as the fourth set of channels <NUM> extend axially along axial direction <NUM> towards the upstream inlet <NUM>. The tapering of the fourth subset of bend lines <NUM> in the transverse direction <NUM> provides the decreasing transverse channel height <NUM> of the fourth set of channels <NUM>.

Incoming dirty fluid <NUM> to be filtered flows along axial direction <NUM> into open channels <NUM> at the upstream inlet <NUM> and passes laterally and/or transversely through the filter media wall segments of the filter media <NUM> and then flows axially along axial direction <NUM> as clean filtered fluid <NUM> through open channels <NUM> at the downstream outlet <NUM>. Second subset of bend lines <NUM> provides lateral cross-flow thereacross along lateral direction <NUM> between respective channels downstream of the upstream inlet <NUM>. Fourth subset of bend lines <NUM> provides lateral cross-flow thereacross along lateral direction <NUM> between respective channels upstream of the downstream outlet <NUM>. Second and fourth subsets of bend lines <NUM> and <NUM> have axially overlapping sections <NUM>, and the noted lateral cross-flow is provided at least at axially overlapping sections <NUM>.

The second subset of bend lines <NUM> taper to respective termination points <NUM>, <FIG>, providing at such termination points the minimum transverse channel height <NUM> of the second set of channels <NUM>. The fourth subset of bend lines <NUM> taper to respective termination points <NUM> providing at such termination points the minimum transverse channel height <NUM> of the fourth set of channels <NUM>. Termination points <NUM> of second subset of bend lines <NUM> are axially downstream of termination points <NUM> of fourth subset of bend lines <NUM>. This provides the noted axially overlapping sections <NUM>. Termination points <NUM> of second subset of bend lines <NUM> are at the downstream outlet <NUM> in one embodiment, and in other embodiments are axially upstream of the downstream outlet <NUM>. Termination points <NUM> of fourth subset of bend lines <NUM> are at the upstream inlet <NUM> in one embodiment, and in other embodiments are axially downstream of the upstream inlet <NUM>.

The first set of wall segments <NUM> are alternately sealed to each other at adhesive <NUM> at the upstream inlet <NUM> define a first set of tetrahedron channels <NUM> having open upstream ends, and a second set of tetrahedron channels <NUM> interdigitated with the first set of tetrahedron channels <NUM> and having closed upstream ends. The second set of wall segments <NUM> are alternately sealed to each other at adhesive <NUM> at the downstream outlet <NUM> define a third set of tetrahedron channels <NUM> having closed downstream ends, and a fourth set of tetrahedron channels <NUM> interdigitated with the third set of tetrahedron channels <NUM> and having open downstream ends. The first set of bend lines <NUM> includes the first subset of bend lines <NUM> defining the first set of tetrahedron channels <NUM>, and the second subset of bend lines <NUM> defining the second set of tetrahedron channels <NUM>. The second subset of bend lines <NUM> taper in the transverse direction <NUM> as they extend from the upstream inlet <NUM> axially towards the downstream outlet <NUM>. The second set of bend lines <NUM> includes the third subset of bend lines <NUM> defining the third set of tetrahedron channels <NUM>, and the fourth subset of bend lines <NUM> defining the fourth set of tetrahedron channels <NUM>. The fourth subset of bend lines <NUM> taper in the transverse direction <NUM> as they extend from the downstream outlet <NUM> axially towards the upstream inlet <NUM>.

First and second sets of tetrahedron channels <NUM> and <NUM>, shown in <FIG>, face oppositely to third and fourth sets of tetrahedron channels <NUM> and <NUM>. Each of the tetrahedron channels <NUM>, <NUM>, <NUM>, <NUM> is elongated in the axial direction <NUM>. Each of the tetrahedron channels has a cross-sectional area along a cross-sectional plane defined by the transverse and lateral directions <NUM> and <NUM>. The cross-sectional areas of the first and second sets of tetrahedron channels <NUM> and <NUM> decrease as the first and second sets of tetrahedron channels <NUM> and <NUM> extend along axial direction <NUM> from the upstream inlet toward the downstream outlet <NUM>. The cross-sectional areas of third and fourth sets of tetrahedron channels <NUM> and <NUM> decrease as the third and fourth sets of tetrahedron channels <NUM> and <NUM> extend along axial direction <NUM> from the downstream outlet <NUM> toward the upstream inlet. In one embodiment, bend lines <NUM> are bent at a sharp pointed angle, as shown at <NUM>, <FIG>. In other embodiments, the bend lines are rounded along a given radius, as shown in dashed line at <NUM>, <FIG>.

The filter media <NUM> is further provided with a substantially flat sheet <NUM> extending laterally across the bend lines. In one embodiment, the sheet is formed of filter media material, which may be the same filter media material as the filter element including wall segments <NUM>. Sheet <NUM> extends axially along the full axial length along axial direction <NUM> between the upstream inlet and the downstream outlet <NUM>, and extends laterally along the full lateral width along lateral direction <NUM> across and sealing the channels to prevent bypass of dirty upstream air to clean downstream air without passing through and being filtered by a wall segment <NUM>. In one embodiment, sheet <NUM> is rectiplanar along a plane defined by axial direction <NUM> and lateral direction <NUM>. In another embodiment, sheet <NUM> is slightly corrugated, as shown in dashed line at <NUM>, <FIG>. In one implementation, sheet <NUM> is rolled with the filter media <NUM> into a closed loop, and in various embodiments or examples the closed loop has a shape selected from the group of circular, <FIG>, racetrack (two curved ends joined by two straight or substantially straight portions), <FIG>, oval, oblong, and other closed-loop shapes. In other examples, a plurality of filter media layers <NUM> and sheets are stacked upon each other in a stacked panel arrangement, <FIG>. Spacer strips or embossments such as <NUM> may be used as needed for spacing and support between stacked elements.

<FIG> show a further embodiment eliminating sheet <NUM> and are like <FIG> and use like reference numerals from above where appropriate to facilitate understanding.

The filter element of <FIG> has an upstream inlet <NUM> receiving incoming dirty fluid, and a downstream outlet <NUM> discharging clean filtered fluid. The wall segments are alternately sealed to each other at upstream inlet <NUM> as above, e.g. by adhesive or a section of filter media at <NUM>, to define the noted first set of channels <NUM> having open upstream ends, and the noted second set of channels <NUM> interdigitated with the first set of channels and having closed upstream ends. The wall segments are alternately sealed to each other at the downstream outlet <NUM>, e.g. by adhesive or a section of filter media at <NUM>, to define the noted third set of channels <NUM> having closed downstream ends, and the noted fourth set of channels <NUM> having open downstream ends. The bend lines include the noted first subset of bend lines <NUM> defining the first set of channels <NUM>, and the noted second subset of bend lines <NUM> defining the noted second set of channels <NUM>, and the noted third subset of bend lines <NUM> defining the third set of channels <NUM>, and the noted fourth subset of bend lines <NUM> defining the noted fourth set of channels <NUM>.

The elongated tetrahedron channels allow for cross-flow between adjacent channels. In air filter implementations, this cross-flow allows for more even dust loading on the upstream side of the media. In one embodiment, the elongated tetrahedron channels are shaped to purposely allow for more upstream void volume than downstream void volume, to increase filter capacity. Various fluids may be filtered, including air, air/fuel mixture or other gases, and including liquids such as fuel, lubricants or water.

In various examples, a plurality of filter media layers maybe stacked such that at least one edge or corner of one layer is not aligned with a corresponding edge or corner of another layer disposed thereon. This allows for formation of complex shaped filter elements that provide flexibility in installation. For example, <FIG> is a front view, and <FIG> is a perspective view of a filter element <NUM> having a rhomboidal cross-section, according to an example. The filter element <NUM> includes a filter media pack <NUM> (e.g., comprising a tetrahedral filter media) having a polymeric layer <NUM> disposed on at least one sidewall of a plurality of sidewalls thereof that are parallel to a flow axis of the filter element <NUM>. The filter media pack <NUM> defines an inlet surface <NUM> through which unfiltered fluid enters the filter media pack <NUM>, and an outlet surface <NUM> through which filtered fluid is expelled from the filter media pack <NUM>.

The filter media pack <NUM> comprises a plurality of filter media layers having the same length that are stacked such that an edge thereof is offset from a corresponding edge of a subsequently stacked filter media layer such that the filter media pack <NUM> has a rhomboidal or parallelogram cross-section. For example, the filter media pack <NUM> includes a first filter media layer 222a and a second filter media layer 222b disposed on top of the first filter media layer 222a. A second filter media layer first edge 223b of the second filter media layer 222b is offset a predetermined distance from a corresponding first filter media layer first edge 223a of the first filter media layer 222a. As the first filter media layer 222a and the second filter media layer 222b have the same length, a second filter media layer second edge 225b opposite the second filter media layer first edge 223b is also offset from a corresponding first filter media layer second edge 225a, i.e., the filter media layers 222a/b are staggered. This is repeated for each of the filter media layers in the stack such that the filter media pack <NUM> has a rhomboidal cross-section (i.e., has a parallelogram shape).

In various examples, a plurality of different or unequal length filter media layers maybe stacked such that at least one edge or corner of one layer is not aligned with a corresponding edge or corner of another layer disposed thereon. For example, <FIG> is a front view, and <FIG> is a perspective view of a multilayered filter element <NUM> having a wedge shaped sidewall, according to another example. The filter element <NUM> includes a filter media pack <NUM> (e.g., comprising a tetrahedral filter media) having a polymeric layer <NUM> disposed on at least one sidewall of a plurality of sidewalls thereof that are parallel to a flow axis of the filter element <NUM>. The filter media pack <NUM> defines an inlet surface <NUM> through which unfiltered fluid enters the filter media pack <NUM>, and an outlet surface <NUM> through which filtered fluid is expelled from the filter media pack <NUM>.

The filter media pack <NUM> comprises a plurality of filter media layers having different lengths that are stacked such that one edge of a second filter media layer is offset from a corresponding edge of a first filter media layer on which the second filter media layer is disposed, such that a sidewall <NUM> formed by the corresponding offset edges of the plurality of filter media layers defines a triangular wedge shape. For example, the filter media pack <NUM> includes a first filter media layer 322a and a second filter media layer 322b disposed on top of the first filter media layer 322a. A second filter media layer first edge 323b of the second filter media layer 322b is aligned with a corresponding first filter media layer first edge 323a of the first filter media layer 322a. As the first filter media layer 322a and the second filter media layer 322b have different lengths, a second filter media layer second edge 325b opposite the second filter media layer first edge 323b is offset from a corresponding first filter media layer second edge 325a. This is repeated for each of the filter media layers in the stack till a center line of the filter media pack <NUM>, i.e., progressively longer filter media layers are stacked till the center line of the filter media pack <NUM>, after which progressively shorter filter media layers are stacked, such that the sidewall <NUM> defines a triangular wedge shape (i.e., the filter media pack <NUM> has a pentagon wedge shaped).

In other examples, different or unequal length filter media layers may be stacked such that one sidewall of the filter media pack defines a curvature. For example, <FIG> is a front view, and <FIG> is a perspective view of a multilayered filter element <NUM> having a curved sidewall, according to still another example. The filter element <NUM> includes a filter media pack <NUM> (e.g., comprising a tetrahedral filter media) having a polymeric layer <NUM> disposed on a plurality of sidewalls thereof that are parallel to a flow axis of the filter element <NUM>. The filter media pack <NUM> defines an inlet surface <NUM> through which unfiltered fluid enters the filter media pack <NUM>, and an outlet surface <NUM> through which filtered fluid is expelled from the filter media pack <NUM>. The filter media pack <NUM> is constructed similar to filter media pack <NUM> with the difference that a second filter media layer edge 425b of a second filter media layer 422b is offset from a corresponding first filter media layer edge 425a of a first filter media layer 422a on which the second filter media layer 422b is disposed. This is repeated for each of the filter media layers in the stack till a center line of the filter media pack <NUM>, i.e., progressively longer filter media layers are stacked till the center line of the filter media pack <NUM>, after which progressively shorter filter media layers are stacked, such that the sidewall <NUM> defines a curvature, for example, a rounded or semi-circular shape, or include a continuous asymmetric curvature defined by a spline.

In some examples, different or unequal length filter media layers may be stacked to form a filter media pack such that an outlet surface of the filter media pack forms triangular wedge shape. For example, <FIG> is a back view and <FIG> is a front perspective view of a multilayered filter element <NUM> having a wedge shaped outlet surface, according to yet another example. The filter element <NUM> includes a filter media pack <NUM> (e.g., comprising a tetrahedral filter media) having a polymeric layer <NUM> disposed on a plurality of sidewalls thereof that are parallel to a flow axis of the filter element <NUM>. The filter media pack <NUM> defines an inlet surface <NUM> through which unfiltered fluid enters the filter media pack <NUM>, and an outlet surface <NUM> through which filtered fluid is expelled from the filter media pack <NUM>. The filter media pack <NUM> is constructed similar to filter media pack <NUM> with the difference that a second filter media layer edge 523b of a second filter media layer 522b is offset from a corresponding first filter media layer edge 525a of a first filter media layer 522a on which the second filter media layer 522b is disposed, the corresponding edges forming the outlet surface <NUM>. This is repeated for each of the filter media layers in the stack till a center line of the filter media pack <NUM>, i.e., progressively longer filter media layers are stacked till the center line of the filter media pack <NUM>, after which progressively shorter filter media layers are stacked, such that the outlet surface <NUM> forms a triangular wedge shape.

<FIG> show various views of a multilayered filter element <NUM> having a complex shape with curved sidewalls, according to another example. The filter element <NUM> includes a filter media pack <NUM> (e.g., comprising a tetrahedral filter media) having a polymeric layer <NUM> disposed on a plurality of sidewalls thereof that are parallel to a flow axis of the filter element <NUM>. The filter media pack <NUM> defines an inlet surface <NUM> through which unfiltered fluid enters the filter media pack <NUM>, and an outlet surface <NUM> through which filtered fluid is expelled from the filter media pack <NUM>.

The filter media pack <NUM> includes a plurality of filter media layers stacked on each other to form the filter media pack <NUM>. Each filter media layer of the plurality of filter media layers may have the same length or different lengths. A second filter media layer first corner 621b of a second filter media layer 622b is aligned with a corresponding first filter media layer first corner 621a of a first filter media layer 622a on which the second filter media layer 622b is disposed. Furthermore, a second filter media layer second corner 623b of the second filter media layer 622b diagonally opposite the second filter media layer first corner 621b of the second filter media layer 622b, is rotationally offset from a corresponding first filter media layer second corner <NUM> a of the first filter media layer 622a. This is repeated for the subsequently stacked filter media layers such that the filter media pack <NUM> has a continuously curving shape.

While various examples have been described with respect to <FIG>, these examples are non-limiting and various other examples or multilayers filter media packs are envisioned. For example, in various embodiments, the offset between individual filter media layers in a filter media pack may not to be consistent in size through the layered media pack. In some embodiments, a filter media pack may be formed using filter media layers such that the filter media pack has a swooped arched shape, includes a portion of filter media layers that are partially offset and then are flat stacked (i.e., are no offset from each other), includes a combination of shapes (e.g., arch, fixed, flat, etc. in a single filter media pack), or includes asymmetric length filter media layers such that the filter media pack has an asymmetric shape.

In some embodiments, a filter element may include a plurality of filter media layers stacked on a core. For example, <FIG> is a front view, and <FIG> is a perspective view of a multilayered filter element <NUM> having a semi-circular cross-sectional shape, according to an embodiment. The filter element <NUM> includes a filter media pack <NUM> (e.g., comprising a tetrahedral filter media) having a polymeric layer <NUM> disposed on a plurality of sidewalls thereof that are parallel to a flow axis of the filter element <NUM>. The filter media pack <NUM> defines an inlet surface <NUM> and an outlet surface <NUM>.

The filter element <NUM> may comprise a core <NUM>. A plurality of filter media layers are stacked on an outer surface of the core <NUM> to form the filter media pack <NUM>. The core <NUM> may be formed from plastic, polymers or any other suitable material. The filter media layers have different lengths such that the outer edges of the stacked filter media layers are aligned. For example, as shown in <FIG>, a first filter media layer 922a having a first length is disposed on a portion <NUM> of the core <NUM>. A second filter media layer 922b having a second length longer than the first length is disposed on the first filter media layer 922a such that outer edges of the first filter media layer 922a and the second filter media layer 922b are aligned.

The portion <NUM> of the core <NUM> define a curved surface such that the filter media pack <NUM> conforms to the shape of the core <NUM> and defines a filter media pack cross-sectional shape corresponding to a curvature of the portion <NUM>. For example, as shown in <FIG>, the portion <NUM> is hemispherical such that the filter media pack <NUM> defines a hemispherical shape. An opposite portion <NUM> of the core is rectiplanar, but in other embodiments, may also be circular. In still other embodiments, the portion <NUM> may have any other suitable shape, for example, oval, elliptical, polygonal, asymmetrical or any other suitable shape, and the filter media pack <NUM> has a corresponding shape. Once formed, the core <NUM> may be removed from the filter element <NUM> such that the filter element <NUM> such that the filter media pack <NUM> defines a central channel defining a central channel cross-sectional shape corresponding to the filter media pack cross-sectional shape. The central channel may then be sealed or plugged (e.g., via end caps or sealant such as polyurethane).

In various embodiments, a filter element may include a layered filter media pack that has a non-circular shape. For example, <FIG> is a perspective view of a filter element <NUM>, according to an embodiment. The filter element <NUM> includes a core <NUM> having a non-circular core cross-sectional shape, for example, a triangular cross-section as shown in <FIG>, but may have any other suitable cross-section. The filter element <NUM> includes a filter media pack <NUM> (e.g., comprising a tetrahedral filter media) disposed around an outer periphery of the core <NUM>. Expanding further, the filter media pack <NUM> comprises a plurality of filter media layers 1022a stacked on an outer periphery of the core <NUM> such that the filter media pack <NUM> has a filter media pack cross-sectional shape that corresponds to the core cross-sectional shape, for example, is substantially triangular but has rounded edges. In other embodiments, the filter element <NUM> may include a filter media layer wrapped around the outer periphery of the core <NUM> such that the filter media pack <NUM> is a coiled filter media pack. In the implementation shown in <FIG>, the core has a triangular core cross-section such that the filter media pack <NUM> has a tri-lobal shape so as to have a triangular cross-section. A bond <NUM> may be formed across a width of the filter media pack <NUM> to secure the wrapped filter media pack <NUM> and prevent the filter media pack <NUM> from unwrapping. In some embodiments, a polymeric layer <NUM> (e.g., a urethane or polyurethane layer, rubbers, silicones, etc.) may be disposed on an outer surface of the filter media pack <NUM> parallel to a flow axis of the filter media pack <NUM>, as previously described herein. Once formed, the core <NUM> may be removed from the filter element <NUM> such that the filter element <NUM> such that the filter media pack <NUM> defines a central channel defining a central channel cross-sectional shape corresponding to the non-circular filter media pack cross-sectional shape (i.e., has a triangular shape or tri-lobal shape). The central channel may then be sealed or plugged (e.g., via end caps or sealant such as polyurethane).

<FIG> shows a side perspective view of a core <NUM> according to an example included in the filter element <NUM>. The core <NUM> has a uniform cross-section from a first end <NUM> to a second end <NUM> thereof that is opposite the first end <NUM>. The core <NUM> may be formed from plastic, paper, cardboard, polymers or any other suitable material. In some embodiments, the core <NUM> may be solid. In other embodiments, the core <NUM> may be hollow.

<FIG> is a side perspective view of a core <NUM>, according to an embodiment. Different from the core <NUM>, the core <NUM> comprises a central shaft <NUM> extending longitudinally from a first end <NUM> to a second end <NUM> thereof opposite to the first end <NUM>. The central shaft <NUM> has a circular cross-section. A plurality of circumferential ribs <NUM> protrude radially from the central shaft <NUM> at predetermined locations on the central shaft <NUM>, for example, offset at a fixed distance from each other. Each of the plurality of circumferential ribs <NUM> define the core cross-section, i.e., have the triangular cross-section. In particular embodiments, a first circumferential rib 1146a of the plurality of circumferential ribs <NUM> disposed at the first end <NUM> of the central shaft <NUM> comprises a rib sidewall 1148a extending from outer edges of the first circumferential rib 1146a away from the central shaft <NUM> such that a cavity 1149a is defined between the first circumferential rib 1146a and the rib sidewall 1148a. In various embodiments, the cavity 1149a may be configured to receive a correspondingly shaped pin or key, for example, to be inserted into the cavity 1149a and be rotated for stacking the filter media layer 1022a on the core <NUM> so as to form the filter media pack <NUM>.

While the filter element <NUM> includes a triangular shaped core <NUM> so that the filter media pack <NUM> has a triangular or tri-lobal core cross-sectional shape, in other embodiments, any other core having any other core cross-sectional shape may be used, for example, a polygonal cross-sectional shape. For example, <FIG> is a perspective view of a wrapped filter element <NUM> that includes a filter media pack <NUM> (e.g., comprising a tetrahedral filter media) wrapped around a core <NUM>. The core <NUM> has a core cross-sectional shape comprising a rhombus or parallelogram such that the filter media pack <NUM> also has a rhomboidal cross-sectional shape. The core <NUM> can be removed such that the filter media pack <NUM> defines a central channel having a rhomboidal cross-sectional shape. In other embodiments, the filter element <NUM> may include a filter media layer wrapped around the outer periphery of the core <NUM> such that the filter media pack <NUM> is a coiled filter media pack.

<FIG> is a perspective view of a wrapped filter element <NUM> that includes a filter media pack <NUM> (e.g., comprising a tetrahedral filter media) comprising a plurality of filter media layers stacked on an outer surface of a core <NUM>. The core <NUM> has a polygonal core cross-sectional shape such that the filter media pack <NUM> also has a polygonal cross-section corresponding to the core cross-section. The core <NUM> can be removed such that the filter media pack <NUM> defines a central channel having a polygonal cross-sectional shape. In other embodiments, the filter element <NUM> may include a filter media layer wrapped around the outer periphery of the core <NUM> such that the filter media pack <NUM> is a coiled filter media.

In some embodiments, a stacked filter media pack may include an integrated housing bonded or sealed via a sealing member to an outer surface of the stacked filter media pack. For example, <FIG> is a cross-section view of a filter assembly <NUM>, according to an embodiment. The filter assembly <NUM> comprises a filter element <NUM> having a core <NUM>, and a filter media pack <NUM> (e.g., comprising a tetrahedral filter media) having a plurality of filter media layers stacked on an outer periphery of the core <NUM>. While <FIG> shows the core <NUM> as having a circular cross-section, in other embodiments, the core <NUM> may have any other suitable cross-section, for example, rhomboidal, square, rectangular, polygonal, elliptical, oval, asymmetrical, etc. In some embodiments, the core <NUM> may include a center tube.

The filter assembly <NUM> also comprises a filter housing <NUM>. The filter housing <NUM> includes a housing portion <NUM> defining an internal volume within which the filter element <NUM> is disposed. An outer radial surface of the filter media pack <NUM> is bonded to an inner radial surface of the housing portion <NUM>. For example, the housing portion <NUM> may be separately formed and then the filter element <NUM> inserted into the housing portion <NUM> thereof, and the outer radial surface of the filter media pack <NUM> bonded or sealed to the inner radial surface of the housing portion <NUM>. In other embodiments, the filter housing <NUM> may be molded over the filter element <NUM>, or formed by coating (e.g., spray coating or dip coating) a polymeric material (e.g., foam urethane or structural polyurethane) on the outer radial surface of the filter media pack <NUM> so as to form the filter housing <NUM> bonded to the outer radial surface of the filter media pack <NUM>. In this manner, filter assemblies are realized in which the entire cross-section of the filter housing <NUM> is utilized by the filter element <NUM> disposed therein.

The filter housing <NUM> also includes a coupling portion <NUM> fluidly coupled to the housing portion <NUM> distal from the filter element <NUM>. The coupling portion <NUM> defines an opening <NUM> for allowing fluid to flow therethrough, for example, allow unfiltered fluid to flow into the housing portion <NUM> and serve as an inlet of the filter housing <NUM>, or allow filtered fluid to be expelled from the filter housing <NUM>, therefore serving as an outlet of the filter housing <NUM>. In some embodiments as shown in <FIG>, the coupling portion <NUM> has a smaller cross-section than the housing portion <NUM>. In such embodiments, a connecting wall <NUM>, for example, a tapered or curved wall, extends from a rim of the coupling portion <NUM> to a rim of the housing portion <NUM> so as to fluidly couple the coupling portion <NUM> to the housing portion <NUM>.

The coupling portion <NUM> is configured to be coupled to a conduit. <FIG>show a conduit <NUM> coupled to the coupling portion <NUM>, according to a particular embodiment. The core <NUM> is hollow, and an aperture <NUM> is defined on an end wall <NUM> of the core <NUM> disposed perpendicular to a longitudinal axis of the filter assembly <NUM> distal from the coupling portion <NUM>. A rod <NUM> extends from the conduit <NUM> through the hollow core <NUM> and through the aperture <NUM>. The rod <NUM> is coupled to an inner surface of the conduit <NUM>, for example, via a screw, nut, bolt, or welded thereto.

The filter assembly <NUM> also comprises a knob <NUM> configured to removably engage the rod <NUM>, i.e., a portion of the rod <NUM> that protrudes through the aperture <NUM>, to secure the filter assembly <NUM> to the conduit <NUM>. For example, as shown in <FIG>, the portion of the rod <NUM> protruding through the aperture <NUM> may define threads on an outer surface thereof. The knob <NUM> defines a throughhole having mating threads formed on an inner surface of the throughhole, that are structured to removably engage the threads of the rod <NUM> so as to removably couple the filter assembly <NUM> to the conduit <NUM>.

The conduit <NUM> comprises a circumferential ledge <NUM> protruding radially from an outer surface of the conduit <NUM>. The coupling portion <NUM> is configured to be disposed circumferentially around a portion of the conduit <NUM> such that an axial edge of the coupling portion <NUM> contacts the ledge <NUM> and may form an axial seal therewith. Expanding further, as the knob <NUM> engages the rod <NUM>, a surface of the knob <NUM> contacts the corresponding end wall <NUM> of the core <NUM> and pushes the core <NUM>, and thereby the filter element <NUM> and the filter housing <NUM> towards the conduit <NUM>. This causes the axial end of the coupling portion <NUM> to press against the ledge <NUM>, thereby creating an axial seal between the axial edge of the coupling portion <NUM> and the ledge <NUM>. In some embodiments, a radial seal member may be used to seal the coupling portion <NUM> to the conduit <NUM>. In such embodiments, the circumferential ledge <NUM> may be excluded.

<FIG> is a side cross-section view, and <FIG> is a front perspective view of a filter assembly <NUM> including a filter element <NUM> coupled to a conduit <NUM>, according to another embodiment. The filter element <NUM> is similar to the filter element <NUM> and includes the filter media pack <NUM> disposed in the housing portion <NUM> of the filter housing <NUM>. Different from the core <NUM>, the filter assembly <NUM> includes a hollow core <NUM> that has an end wall <NUM> that does not include an aperture defined therethrough.

The coupling portion <NUM> of the filter housing <NUM> is disposed circumferentially around the outer surface of the conduit <NUM>. The filter assembly <NUM> further comprises a clamp <NUM> disposed around the coupling portion <NUM> so as to secure the coupling portion <NUM> to the conduit <NUM>. For example, as shown in <FIG>, the clamp <NUM> includes a circular band provided with a lead screw <NUM> that is configured to tighten the clamp <NUM> (i.e., reduce a circumference thereof) so as to secure the coupling portion <NUM> to the conduit <NUM>.

While <FIG> and <FIG> show the cores <NUM>, <NUM> as having a circular cross-section, in other embodiments, the filter assembly <NUM>, <NUM> may include cores having any suitable cross-section. In some embodiments, the core for the filter assembly <NUM>, <NUM> may have a non-circular core cross-section, such that the filter media pack wrapped therearound has a filter media pack cross-sectional shape corresponding to the core cross-sectional shape. For example, the core cross-sectional shape may be a triangular, polygonal, rhomboidal, elliptical, or oval, and the filter media pack cross-sectional shape corresponds to the core cross-sectional shape.

Filter media packs generally have an inlet surface and an outlet surface that is flat. In certain situations, shapes of inlet or outlet conduits coupled to the filter element may create restrictions on shapes of the filter element. In various embodiments, an inlet surface or an outlet surface of a filter media pack may define a curvature or generally a non-flat profile. For example, <FIG> are various views of a filter element <NUM>, according to an embodiment. The filter element <NUM> comprises a filter media pack <NUM> (e.g., comprising a tetrahedral filter media) that may be stacked on or wrapped around an outer surface of a core <NUM>. The core <NUM> is hollow, but in other embodiments, a solid core may be used.

A polymeric layer <NUM> (e.g., a foam urethane or structural polyurethane) is disposed on an outer surface of the filter media pack <NUM>. The filter media pack <NUM> includes an inlet surface <NUM> configured to receive unfiltered fluid, and an outlet surface <NUM> configured to expel filtered fluid from the filter media pack <NUM>. A radial seal member <NUM> is disposed circumferentially around the filter media pack <NUM> proximate to the inlet surface <NUM>. A support structure <NUM> disposed circumferentially around the filter media pack <NUM> proximate to the outlet surface <NUM> and coupled thereto. As shown in <FIG>, the inlet surface <NUM> defines a concave shaped curvature curving inwards from outer edges of the inlet surface <NUM>, and the outlet surface <NUM> defines a convex shaped curvature curving outwards from the filter media pack <NUM>. For example, as filter media layers are stacked on the core <NUM>, each filter media layer is axially offset from the previous layer, or a filter media layer is wrapped around the core <NUM> to form the filter media pack <NUM>, each subsequent coil is offset slightly from the previous coil so as to produce the concave shaped inlet surface <NUM> and the convex shaped outlet surface <NUM>. Such a shape may maximize space utilization and allows installation in filter housing having non-flat inlet and outlet surfaces.

<FIG> is a side cross-section view of a filter element <NUM>, according to another embodiment. The filter element <NUM> includes a filter media pack <NUM> stacked on or wrapped around a core <NUM>. The filter media pack <NUM> is stacked or wrapped such that an inlet surface <NUM> tapers from a rim of the inlet surface <NUM> towards the core <NUM>, and an outlet surface <NUM> thereof tapers outwardly from an outer edge of the outlet surface towards the core <NUM> such that the inlet surface <NUM> and the outlet surface <NUM> have a chevron shape.

<FIG> is a side cross-section view of a filter element <NUM>, according to another embodiment. The filter element <NUM> includes the filter media pack <NUM> stacked on or wrapped around the core <NUM> such that the inlet surface <NUM> defines a circumferential chevron shape or V-shape projecting inwards from the core <NUM>, and the outlet surface <NUM> defines an outward projecting chevron or V shape. In other embodiments, the inlet surface <NUM> and/or the outlet surface <NUM> may include a gradual transition in shape that then reverses direction.

Various coupling structures may be used to secure a filter element (e.g., any of the filter elements described herein) within a filter housing, and allow swift coupling and uncoupling of a filter element from a filter housing. For example, <FIG> shows a perspective view of a portion of an inner surface of a filter housing <NUM>, and <FIG> shows an outer surface of a filter element <NUM>, according to an embodiment. A circular protrusion <NUM> projects radially inwards from the inner surface of the filter housing <NUM>, and a corresponding engagement feature comprising a ledge <NUM> protrudes radially outwards from an outer surface of the filter element <NUM>. In other embodiments, the protrusion <NUM> may be formed on an outer surface of the filter element <NUM>, and the ledge <NUM> formed on an inner surface of the filter housing <NUM>. The ledge <NUM> includes a curved portion <NUM> such that the ledge <NUM> has an eyebrow shape. The curved portion <NUM> defines a curvature corresponding to an arc segment of the circular protrusion <NUM> and is configured to engage the circular protrusion <NUM> as shown in <FIG> to secure the filter element <NUM> to the filter housing <NUM>.

<FIG> show various embodiments of coupling structures for securing a filter element within a filter housing. For example, <FIG> shows a side cross-section view of a filter housing <NUM>, according to an embodiment. A plurality of ramps or slots <NUM> are defined (e.g., molded) into an inner surface of a sidewall <NUM> of the filter housing <NUM> proximate to a base <NUM> of the filter housing <NUM>. <FIG> shows a side view, and <FIG> shows a top view of a filter element <NUM>, according to an embodiment. The filter element <NUM> comprises a plurality of mating engagement features configured to engage the ramps <NUM>. Each of the engagement feature comprises a curved rib <NUM> protruding radially outwards from an outer surface of the filter element <NUM> (e.g., defined on an outer surface of an end plate coupled to a filter media pack of the filter element <NUM>). The curved rib <NUM> is configured to slide into the corresponding ramp <NUM> so as to secure the filter element <NUM> within the filter housing <NUM>.

<FIG> shows a side cross-section view of a filter housing <NUM>, according to an embodiment. Filter housing threads <NUM> are defined on an inner surface of a sidewall <NUM> of the filter housing <NUM> proximate to a base <NUM> thereof. <FIG> shows a side view of a filter element 2210a, according to one embodiment. Filter element threads 2217a are defined on a sidewall of an end plate 2216a of the filter element 2210a, and are configured to matingly engage the filter housing threads <NUM> to secure the filter element 2210a within the filter housing <NUM>. <FIG> is a side view of a filter element 2210b, according to another embodiment. The filter element 2210b is similar to the filter element 2210a, and includes an end plate 2216b having filter element threads 2217b defined on a sidewall thereof and configured to engage the filter housing threads <NUM>. Furthermore, the end plate 2216b also includes a circular sealing member 2219b projecting axially from an end plate base 2218b of the end plate 2216b, and is configured to form an axial seal with an inner surface of the base <NUM> of the filter housing <NUM>.

<FIG> shows a side cross-section view of a filter housing <NUM>, according to yet another embodiment. A plurality of ramps <NUM> are defined (e.g., molded) into an inner surface of a sidewall <NUM> of the filter housing <NUM>. <FIG> shows a side view, and <FIG> shows a top view of a filter element <NUM>, according to an embodiment. The filter element <NUM> comprises a plurality of mating engagement features configured to engage the ramps <NUM>. Each of the engagement feature comprises a lug <NUM> protruding radially outwards from an outer surface of the filter element <NUM> (e.g., defines on an outer surface of an end plate coupled to a filter media pack of the filter element <NUM>). The lug <NUM> is configured to slide into the corresponding ramp <NUM> so as to secure the filter element <NUM> within the filter housing <NUM>.

<FIG> is a front perspective view of a filter assembly <NUM> including a filter housing <NUM> having a plurality of filter housing segments <NUM>, each configured to house a filter element <NUM> therein, according to an embodiment. The filter housing <NUM> includes a base <NUM> that has tapered cross-section that reduces in thickness to an outlet <NUM>. In other words, the fluid outlet <NUM> has a smaller cross-section (e.g., diameter) relative to a cross-section of an end of the base <NUM> opposite to the outlet <NUM>.

The filter housing <NUM> also includes a plurality of filter housing segments <NUM> extending from an outer periphery of the base <NUM> in a direction away from the outlet <NUM>. Each of the plurality of filter housing segments <NUM> has a rectangular cross-section and defines an internal volume configured to house the filter element <NUM> (e.g., any of the filter elements described herein) having a corresponding cross-section. Each of the filter housing segments <NUM> is in fluid communication with the outlet <NUM> through the base <NUM>. The filter housing segments <NUM> are arranged in a semi-circular array by rotationally offsetting each filter housing segment <NUM> relative to the filter housing segment <NUM> disposed adjacent thereto. In other words, the plurality of filter housing segments <NUM> are disposed along an arc segment, as shown in <FIG>. Ribs <NUM> are disposed between the filter housing segments <NUM> to reinforce the filter housing segments <NUM>.

While <FIG> and <FIG> show the plurality of filter housing segments <NUM> arranged in an arc, the plurality of filter housing segments <NUM> can be disposed in any suitable configuration to form a filter housing have any suitable shape. For example, <FIG> shows the plurality of filter housing segments <NUM> disposed in a circular array, <FIG> shows the plurality of filter housing segments <NUM> disposed in a L shaped array, <FIG> shows the plurality of filter housing segments <NUM> disposed in a wavy shape, <FIG> shows the plurality of filter housing segments <NUM> disposed in an oval shape, and <FIG> shows the plurality of filter housing segments <NUM> arranged in a C shape. In this manner, a filter housing having a plurality of filter housing segments can be arranged in any suitable configuration to obtain any suitable shape.

In various embodiments, a filter housing may be configured to serve as a turnbuckle for secure inlet and outlet conduits coupled thereto. Referring now to <FIG>, a filter assembly <NUM> is shown, according to an embodiment. The filter assembly <NUM> includes a filter housing <NUM> defining an inner volume within which a filter element <NUM> is disposed. The filter housing <NUM> may be formed from any suitable material, for example, rubber, plastics, etc..

The filter housing <NUM> includes a first coupling portion <NUM> extending axially from a first end surface <NUM>, and a second coupling portion <NUM> extending from a second end surface <NUM> of the filter housing <NUM>. First housing threads <NUM> are defined on the first coupling portion <NUM> and may include left handed threads. Furthermore, second housing threads <NUM> are defined on the second coupling portion <NUM> and may include right handed threads. Thus, the first coupling portion <NUM> and the second coupling portion <NUM> have threads defined thereon that rotate in opposite directions to each other, analogous to a turnbuckle. Each of the first housing threads <NUM> and the second housing threads <NUM> can have multiple turns (e.g., provide <NUM> degrees of travel), and include partial turn (e.g., provide less than <NUM> degrees of travel).

A first conduit 2830a is coupled to the first coupling portion <NUM>, and a second conduit 2830b is coupled to the second coupling portion <NUM>, the first conduit 2830a being substantially similar to the second conduit 2830b (collectively referred to herein as "conduit 2830a/b"). The conduits 2830a/b may be formed from any suitable material, for example, rubber, plastics or polymers. The first conduit 2830a includes a first conduit inlet portion 2832a for allowing unfiltered fluid to enter the first conduit 2830a and a first conduit coupling portion 2834a defining a plurality of first conduit threads 2835a on an inner surface thereof structured to be coupled to the first housing threads <NUM>. Bellows 2836a are defined between the first conduit inlet portion 2832a and the first conduit coupling portion 2834a, and provide flexibility to the first conduit 2830a by allowing axial compression or extension thereof.

Similarly, the second conduit 2830b includes a second conduit outlet portion 2832b for allowing filtered fluid to be expelled from the second conduit 2830b, and a second conduit coupling portion 2834b defining a plurality of second conduit threads 2835b on an inner surface thereof structured to be coupled to the second housing threads <NUM>. Bellows 2836b are defined between the second conduit outlet portion 2832b and the second conduit coupling portion 2834b.

To couple the conduits 2830a/b to the filter housing <NUM>, the filter housing <NUM> is rotated like a turnbuckle to cause the first housing threads <NUM> to engage the first conduit threads 2835a, and the second housing threads <NUM> to engage the second conduit threads 2835b causing the conduits 2830a/b to axially extend at the bellows 2836a/b such that the conduits 2830a/b are under axial tension. In some embodiments, radial ribs <NUM> may be provided on an outer surface of the filter housing <NUM> as shown in <FIG>, which serve as grippers to facilitate rotation of the filter housing <NUM> relative to the conduits 2830a/b.

<FIG> shows a perspective view of the second conduit 2830b. Sealing members 2837b and 2839b (e.g., sealing rings) are formed on an end face of the second conduit 2830b. Similar sealing members are also defined on an end face of the first conduit 2830a. A plurality of stiffening ribs <NUM> are defined on an outer surface of the second conduit coupling portion 2834b, and may also serve as grippers. Rotation of the filter housing <NUM> in a first direction relative to the conduits 2830a/b causes the end faces of each of the conduits 2830a/b to be drawn in towards the first end surface <NUM> and the second end surface <NUM> such that the sealing members 2837b and 2839b form an axial and/or radial seal with the second end surface <NUM>. Similar sealing members formed on a corresponding end surface of the first conduit 2830a form an axial and/or radial seal with the first end surface <NUM>. The filter housing <NUM> can be uncoupled from the conduits 2830a/b by rotating the filter housing <NUM> in a direction opposite to the first direction, for example, to allow replacement of the filter element <NUM>.

<FIG> is a side view of a filter assembly <NUM> comprising a filter housing <NUM> coupled to the first conduit 2830a and the second conduit 2830b, according to another embodiment. A filter element <NUM> is disposed within the filter housing <NUM>. A first sleeve 2935a and a second sleeve 2935b are over molded over a first conduit coupling portion 2934a and a second conduit coupling portion 2934b of the first conduit 2930a and the second conduit 2930b, respectively. The sleeves 2935a/b are configured to overlap corresponding coupling portions of the filter housing <NUM> and may and be coupled thereto, e.g., friction fit or snap-fit thereto. Sealing members 2937a/b (e.g., a die cut gasket or an O-ring) is disposed between the sleeves 2935a/b and end surfaces of the filter housing <NUM>, and form an axial seal to prevent leakage.

<FIG> is a side cross-section view of a filter assembly <NUM> comprising a filter housing <NUM> coupled to a first conduit 3030a and a second conduit 3030b, according to still another embodiment. A filter element <NUM> is disposed within the filter housing <NUM>. The filter housing <NUM> includes a first coupling portion <NUM> and a second coupling portion <NUM> that extend into the first conduit 3030a and the second conduit 3030b, respectively. First housing threads <NUM> and second housing threads <NUM> are defined circumferentially on the first coupling portion <NUM> and the second coupling portion <NUM>. A radial rib <NUM> protrudes radially from an outer surface of the filter housing <NUM> and serves as a gripper for facilitating rotation of the filter housing <NUM>.

The conduits 3030a/b have bellows 3036a/b defined along a length thereof. A first conduit coupling portion 3034a of the first conduit 3030a is configured to be disposed circumferentially around the first coupling portion <NUM>, and a second conduit coupling portion 3034b of the second conduit 3030b is configured to be disposed around the second coupling portion <NUM>. First conduit threads 3035a and second conduit threads 3035b are configured to couple to the first housing threads <NUM> and the second housing threads <NUM>, respectively. Grippers 3037a/b are formed on an outer surface of the conduit coupling portions 3034a/b and structured to facilitate rotation of the conduits 3030a/b relative to the filter housing <NUM>. Dove tail seals <NUM> are disposed between ends of the conduits 3030a/b and the rib <NUM> formed on the outer surface of the filter housing <NUM>, and form axial and/or radial seal therebetween.

<FIG> is a side cross-section view of a filter assembly 3000a, according to yet another embodiment. The filter assembly 3000a is similar to the filter assembly <NUM> with a difference that instead of the dove tail seals <NUM>, axial compression seals 3022a are used.

<FIG> is a side cross-section view of a filter assembly <NUM> comprising a filter housing <NUM> coupled to a conduit <NUM>, according to still another embodiment. A filter element <NUM> (e.g., comprising a tetrahedral filter media) is disposed within the filter housing <NUM>. A circumferential ledge <NUM> protrudes radially inwards from an inner surface of the filter housing <NUM>. The filter element <NUM> is positioned proximate to the ledge <NUM> and a sealing member <NUM> is positioned between the filter element <NUM> and the ledge <NUM>.

A circumferential rib <NUM> is formed on an outer surface of a coupling portion <NUM> of the filter housing <NUM> downstream of the filter element <NUM>. The conduit <NUM> is disposed circumferentially around the coupling portion <NUM>. Bellows <NUM> are defined in the conduit <NUM> and are configured to engage the circumferential rib <NUM> so as to secure the conduit <NUM> to the filter housing <NUM>. Surfaces of the bellows <NUM> in contact with an outer surface of the filter housing coupling portion <NUM> also form radial seals therewith. A handle <NUM> is formed at an end of the conduit <NUM> which can be engaged by a user to either mount the conduit <NUM> onto the filter housing <NUM> or uncouple the conduit <NUM> therefrom.

<FIG> is a side view of a filter assembly <NUM> comprising a filter element <NUM> configured to be coupled to a conduit <NUM>, according to an embodiment. The filter element <NUM> may be disposed in a filter housing <NUM>, for example, formed by a polymeric layer, as previously described herein. A circumferential rib <NUM> is formed on an outer surface of the filter housing <NUM>, and filter housing threads <NUM> are defined between the rib <NUM> and a filter housing end surface <NUM> of the filter housing <NUM>. A first sealing member <NUM> is disposed on the filter housing end surface <NUM>.

The conduit <NUM> (e.g., a connecting housing) includes a collar <NUM> disposed circumferentially around an outer surface of the conduit <NUM> proximate to a conduit end surface <NUM> that faces the filter element <NUM>. An inner cross-section of the collar <NUM> corresponds to an outer cross-section of the filter housing <NUM> at the rib <NUM>. Collar threads <NUM> are defined on an inner surface of the collar <NUM> and structured to mate with the filter housing threads <NUM>. A conduit rib <NUM> is formed around the conduit <NUM> inwards of the collar <NUM>. The collar <NUM> also includes a collar sidewall <NUM> projecting radially from a rim of the collar <NUM> that is distal from the filter element and may contact the conduit <NUM>.

A circumferential conduit ledge <NUM> protrudes radially outwards from an inner rim of the conduit <NUM> located proximate to the filter element <NUM>. A second sealing member <NUM> is disposed circumferentially around the conduit <NUM> adjacent to the conduit ledge <NUM>. The collar <NUM> is slidingly disposed on the conduit <NUM> and configured slide axially between the conduit rib <NUM> and the conduit ledge <NUM>, the conduit rib <NUM> and the conduit ledge <NUM> serving as motion limiters by engaging the collar sidewall <NUM> so as to define an extent of motion of the collar <NUM>.

<FIG> shows the filter element <NUM> before being coupled to the conduit <NUM>, and <FIG> shows a side view of the filter element after being coupled to the conduit <NUM>. To couple the conduit <NUM> to the filter element <NUM>, the collar <NUM> is axially displaced such that at least a portion of the collar <NUM> overlaps the filter housing <NUM>. The collar <NUM> is then rotated about the conduit <NUM> to cause the collar threads <NUM> to engage the filter housing threads <NUM>. The collar <NUM> slides along the outer surface of the conduit <NUM> until the collar sidewall <NUM> engages the second sealing member <NUM> disposed adjacent to the conduit ledge <NUM>. The collar sidewall <NUM> pulls the conduit <NUM> towards the filter element <NUM> until the first sealing member <NUM> contacts and forms an axial seal with the conduit end surface <NUM>, and the second sealing member <NUM> is squeezed between the collar sidewall <NUM> and the conduit ledge <NUM> so as to form an axial seal therebetween, and may additionally form a radial seal between the inner surface of the collar <NUM> and the outer surface of the conduit <NUM>.

In various embodiments, simple axial and/or radial sealing members may be used to seal any of the filter media packs or filter elements described herein. For example, axial and/or radial sealing members may be used to provide axial or radial fluid sealing of outer surfaces of the various filter elements described herein to inner surfaces of housings within which the filter elements are disposed, and/or to filter heads that the housing may be coupled to.

In other embodiments, complex shaped axial or radial sealing members may be used to seal the various filter elements described herein. For example, in some embodiments, the sealing member may include a humped arched gasket described, for example, in <CIT>. For example, a sealing member includes a keyed interface as shown at 40a in <FIG> is a perspective view of filter element 22a having a border 42a which may be composed of gasket material itself or may have a gasket added thereto. The keyed interface 40a permits installation or replacement of only an authorized filter element 22a mating to the mating interface. The keyed interface permits installation or replacement of the filter element only in a given orientation. The filter element 22a has a border configured to mate with a housing having corresponding grooves at a gasket 42a therebetween and providing the noted mating interface. The gasket 42a and at least one of the housing and the filter element 22a engage each other in detent relation providing the noted keyed interface. The gasket 42a extends along an extension direction along a perimeter. The gasket 42a has one or more projections (such as the humped arches such as 44a as shown in <FIG>), spaced along the perimeter and extending transversely of the noted extension direction. The housing may have one or more concave recessed slits configured to complementally receive respective projections therein. The projections and slits may be regularly or irregularly spaced, and may be symmetric or non-symmetric around the perimeter. In one embodiment, gasket 42a is in-molded to and integral with filter element 22a. The plurality of projections and the plurality of concave recessed slits defined in the housing may be in complemental detent relation engagement and may be selectively spaced along the perimeter to provide dimensional stability of the housing at the gasket 42a in sealing relation along the border. At least one of the sides, shape and spacing of at least the set of one or more projections and the set of one or more concave recessed slits may be selectively configured to allow a one-way fit of the filter element 22a in the housing to ensure correct installation every time. In various embodiments, the keyed interface may include a frame (e.g., a polymer frame) with the projections molded in the gasket 42a disposed thereon, or the projections may be formed directly in a polymeric layer disposed directly on a filter media pack, as previously described herein.

In some embodiments, a sealing member may include a chorded end seal cap as described in <CIT>. For example, <FIG> illustrate one embodiment of an end seal cap 18b of a filter element 12b and a corresponding and mating end cap 8b of a housing chamber having an outlet 16b for emitted air. The end seal cap 18b of the filter element 12b includes internal chords 20b, 22b, which mate with corresponding internal chords 24b, 26b on the end cap 8b of a housing chamber and orient the filter element 12b within the housing chamber, for example, such that the ramp 14b aligns with the inlet 6b of the housing chamber. The shape bounded by the internal chords and inner perimeter of the circle formed by the end seal cap 18b may be any shape (e.g., a non-circular shapes such as an oval, rectangle with rounded corners, racetrack, etc. to facilitate proper orientation of the element). In various embodiments, the end seal cap 18b may include a frame (e.g., a polymer frame) with the internal chords 20b, 22b molded in a gasket 42a disposed thereon, or the internal chords 20b, 22b may be formed directly in a polymeric layer disposed directly on a filter media pack, as previously described herein.

In some embodiments, any of the filter elements or filter media packs described herein may be sealed in a housing using an oval shaped or any other shaped sealing member having various profiles as described in International Patent Application No. <CIT>. For example, referring to <FIG>, various embodiments of seal member profiles are shown. Referring to <FIG>, a seal member profile 700c is shown according to an example embodiment. The seal member profile 700c includes two protrusions 702c (e.g., outwardly curved surfaces) formed on the outer perimeter 714c. The protrusions 702c are positioned on the transverse axis 720c and symmetrically about both the longitudinal axis 710c and the transverse axis 720c such that filter element could be rotated to two positions for installation onto a filter housing (e.g., two degrees of freedom for proper installation).

Referring to <FIG>, a seal member profile 800c is shown according to another example embodiment. The seal member profile 800c includes two protrusions 802c (e.g., outwardly curved surfaces) formed on the outer perimeter 814c. The protrusions 802c are not symmetrically positioned about the longitudinal axis 810c or the transverse axis 820c. However, the protrusions 802c are positioned such that the filter element could be rotated to two positions for installation onto a filter housing (e.g., two degrees of freedom for proper installation).

Referring to <FIG>, a seal member profile 900c is shown according to still another example embodiment. The seal member profile 900c includes two recesses 902c (e.g., inwardly curved surfaces) formed on the outer perimeter 914c. The recesses 902c are positioned on the transverse axis <NUM> and symmetrically about both the longitudinal axis 910c and the transverse axis 920c such that the filter element could be rotated to two positions for installation onto a filter housing (e.g., two degrees of freedom for proper installation).

Referring to <FIG>, a seal member profile 1000c is shown according to yet another example embodiment. The seal member profile 1000c includes two protrusions 1002c (e.g., outwardly curved surfaces) and two recesses 1004c (e.g., inwardly curved surfaces) formed on the outer perimeter 1014c. The protrusions 1002c and recesses 1004c are not symmetrically positioned above the longitudinal axis 1010c or the transverse axis 1020c. However, the protrusions 1002c and recesses 1004c are positioned such that the filter element could be rotated to two positions for installation onto a filter housing (e.g., two degrees of freedom for proper installation). Other various combinations of protrusions and recesses can be used to aid in alignment of a seal with a corresponding sealing interface.

In some embodiments, any of the filter elements or filter media pack described herein may be sealed via a sealing member as described in PCT Application No. <CIT>. For example, a perspective view of a filter element 106d is shown in <FIG>. The filter element 106d comprises filter media pack 112d and a seal member 114d. The filter media pack 112d include, for example, pleated filter media pack arranged in a panel or pleat block or a filter media pack including tetrahedral filter media. Although shown as being generally rectangular in shape, the filter element 106d may be arranged in other shapes, such as a cylinder, an oval, or the like.

The seal member 114d is comprised of may be attached to the filter media pack 112d with an adhesive, such as polyurethane. In some arrangements, the seal member 114d includes an embedded frame member or stiffening member to help maintain the shape of the seal member 114d. In further or additional arrangements, the seal member 114d is connected to the filter media pack 112d through an intermediate frame member, such as a circumferential support. As described in further detail below, the seal member 114d generally includes both planar portions and non-planar portions (i.e., curved, arched, contoured, portions comprised of multiple intersecting sub-portions, etc.) portions configured to interact with matching planar and curved surfaces of a corresponding housing and the cover. The seal member 114d is an axial seal member configured to form a seal with the housing and the cover such that fluid being filtered through a filtration system including the filter element 106d cannot bypass the filter element 106d.

<FIG> shows a portion of the filter element 206d, according to another embodiment, that is configured to be disposed in a housing. The filter element 206d comprises filter media pack 212d and a seal member 214d. The filter media pack 212d may be substantially similar to the filter media pack 112d, as previously described herein. The seal member 214d is comprised of and may be attached to the filter media pack 212d with an adhesive, such as polyurethane. In some arrangements, the seal member 214d may include an embedded frame member or stiffening member to help maintain the shape of the seal member 214d. In further or additional arrangements, the seal member 214d is connected to the filter media pack 212d through an intermediate frame member, such as a circumferential support.

As described in further detail below, the seal member 214d generally includes both planar portions and non-planar portions (i.e., curved, arched, contoured, portions comprised of multiple intersecting sub-portions, etc.) portions configured to interact with matching planar and curved surfaces of a corresponding housing and cover. The seal member 214d may be an axial seal member configured to form a seal with the housing and the cover such that fluid being filtered through a filtration system including the filter element 206d cannot bypass the filter element 206d.

The filter element 206d may be substantially similar in structure and function to the filter element 106d apart from the following difference. The filter element 206d also comprises a plurality of handles 216d extending axially from an end of the filter element 206d. In some embodiments, the plurality of handles 216d may be coupled to the seal member 214d or monolithically formed therewith (e.g., molded with the seal member 214d). In other embodiments, the plurality of handles 216d may be coupled to the intermediate frame member or any other support structure of the filter element 206d. The plurality of handles 216d may facilitate insertion and/or removal of the filter element 206d from the central compartment of the housing 202d.

In some embodiments, a seal member for sealing a filter element and/or a filter media pack may include twists, turns or varying thickness as described in International Patent App. Referring to <FIG>, a perspective view of a filter element 200e is shown according to an example embodiment. The filter element 200e generally comprises a filter media pack 202e and a seal member 204e. The filter media pack 202e may include a pleated filter media pack but in other embodiments may include a filter media pack including tetrahedral filter media. Each face or side of the filter media pack 202e is generally planar in shape. Accordingly, the filter media pack 202e forms a right rectangular cuboid. The filter media pack 202e has a first face 206e and a second face (not shown) opposite the first face 206e and generally parallel to the first face 206e. In some arrangements, the first face 206e is an inlet face and the second face is an outlet face. In such arrangements, air to be filtered flows into the pleat block 202e through the first face 206e, passes through the filter media, and out of the filter media pack 202e through the second face. In other arrangements, the first face 206e is an outlet face, and the flow through the filter media pack 202e is reversed. The filter element 200e is substantially rigid such that the shape of the filter element 200e and the filter media pack 202e is maintained. The rigidity may be achieved through the use of a frame (e.g., a hard urethane frame, an injection molded frame, a thermoformed frame, a roto-molded frame, a 3D printed frame, a stamped metal frame, etc.) or stiffening members (e.g., pleating stabilization beads, spraying the filter media pack 202e edges with a stiffening agent, such as BASFR Elastocast <NUM>, polyurethane, edge bonding, etc.).

The seal member 204e wraps around the filter media pack 202e as shown in <FIG>. The seal member 204e may be formed from and/or attached to the filter media pack 202e with an adhesive (e.g., polyurethane). The seal member 204e is comprised of a flexible material, such as urethane, and is configured to be compressed against a housing to form a seal against a housing. Two lengths of the seal member 204e are arched (i.e., curved) along one axis. The arched lengths of the seal member 204e are configured to interact with complimentarily arched or curved surfaces of a filter housing.

Referring to <FIG>, a perspective view of a filter element 300e is shown according to an example embodiment. The filter element 300e generally comprises a filter media pack 302e and a seal member 304e. The filter media pack 302e may include a pleated filter media pack but in other embodiments may include a filter media pack including tetrahedral filter media. Each face or side of the filter media pack 302e is generally planar in shape. Accordingly, the filter media pack 302e forms a right rectangular cuboid. The filter media pack 302e has a first face 306e and a second face (not shown) opposite the first face 306e and generally parallel to the first face 306e. In some arrangements, the first face 306e is an inlet face and the second face is an outlet face. In such arrangements, air to be filtered flows into the filter media pack 302e through the first face 306e, passes through the filter media, and out of the filter media pack 302e through the second face. In other arrangements, the first face 306e is an outlet face, and the flow through the filter media pack 302e is reversed. The filter element 300e is substantially rigid such that the shape of the filter element 300e and the filter media pack 302e is maintained. The rigidity may be achieved through the use of a frame (e.g., a hard urethane frame, an injection molded frame, a thermoformed frame, a roto-molded frame, a 3D printed frame, a stamped metal frame, etc.) or stiffening members (e.g., pleating stabilization beads, spraying the filter media pack 302e edges with a stiffening agent, such as BASFR Elastocast <NUM>, polyurethane, edge bonding, etc.).

The seal member 304e wraps around the filter media pack 302e as shown in <FIG>. The seal member 304e may be formed from and/or attached to the filter media pack 302e with an adhesive (e.g., polyurethane). The seal member 304e is comprised of a flexible material, such as urethane, and is configured to be compressed against a housing to form a seal against a housing. Each length of the seal member 304e is angled or curved with respect to an axis. The angled or curved lengths of the seal member 304e are configured to interact with complimentarily arched or curved surfaces of a filter housing.

Referring to <FIG>, a perspective view of a filter element 500e is shown according to still another example embodiment. The filter element 500e is a panel filter element. The filter element 500e generally comprises a filter media pack 502e and a seal member 504e. The filter media pack 502e may include a pleated filter media pack but in other embodiments may include a filter media pack including tetrahedral filter media. Each face or side of the filter media pack 502e is generally planar in shape. Accordingly, the filter media pack 502e forms a right rectangular cuboid. The filter media pack 502e has a first face 506e and a second face (not shown) opposite the first face 506e and generally parallel to the first face 506e. In some arrangements, the first face 506e is an inlet face and the second face is an outlet face. In such arrangements, air to be filtered flows into the filter media pack 502e through the first face 506e, passes through the filter media, and out of the filter media pack 502e through the second face. In other arrangements, the first face 506e is an outlet face, and the flow through the filter media pack 502e is reversed. The filter element 500e is substantially rigid such that the shape of the filter element 500e and the filter media pack 502e is maintained. The rigidity may be achieved through the use of a frame (e.g., a hard urethane frame, an injection molded frame, a thermoformed frame, a roto-molded frame, a 3D printed frame, a stamped metal frame, etc.) or stiffening members (e.g., pleating stabilization beads, spraying the filter media pack 502e edges with a stiffening agent, such as BASFR Elastocast <NUM>, polyurethane, edge bonding, etc.).

The seal member 504e wraps around the filter media pack 502e as shown in <FIG>. The seal member 504e may be formed from and/or attached to the filter media pack 502e with an adhesive (e.g., polyurethane) or through a compressive press fit. The seal member 504e is comprised of a flexible material, such as urethane, and is configured to be compressed against a housing to form a seal against a housing. Two lengths of the seal member 504ee are angled with respect to the plane defined by the first face 506e. Additionally, the thickness of the seal member 504e varies from a think end 508e to a thin end 510e. The angled lengths of the seal member 504e are configured to interact with complimentarily arched or curved surfaces of a filter housing.

While <FIG> show various seal members, other seal members that includes features of one or more of the seal members described herein are contemplated. For example, seal members may include non-planar seal members as described in <FIG> that also include the humped arches 44a of <FIG>, the chords 24b, 26b described with respect to <FIG>, seal member profiles as described with respect to <FIG>, or seal members 114d, 214d including notches as described with respect to <FIG>.

It should be noted that the term "example" as used 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).

As utilized herein, the term "substantially" and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed (e.g., within plus or minus five percent of a given angle or other value) are considered to be within the scope of the invention as recited in the appended claims. The term "approximately" when used with respect to values means plus or minus five percent of the associated value.

The terms "coupled," "connected," 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.

It is important to note that the construction and arrangement of the various exemplary 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. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the embodiments described herein.

Claim 1:
A filter element (<NUM>) comprising:
a core (<NUM>) having a non-circular core cross-sectional shape, the core comprising:
a longitudinally extending central shaft (<NUM>);
a plurality of circumferential ribs (<NUM>) protruding radially from the central shaft, each rib of the plurality of circumferential ribs defining the non-circular core cross-sectional shape of the core, a first circumferential rib (1146a) of the plurality of circumferential ribs being disposed at a first end (<NUM>) of the central shaft; and
a rib sidewall (1148a) extending from outer edges of the first circumferential rib and away from the central shaft such that a cavity (1149a) is defined between the first circumferential rib and the rib sidewall, wherein the cavity is configured to receive a correspondingly shaped pin or key;
a filter media pack (<NUM>) comprising a filter media layer wrapped around an outer periphery of the core such that the filter media pack has a filter media pack cross-sectional shape the corresponds to the non-circular core cross-sectional shape;
a seal member (114d), the seal member being an axial seal member configured to form a seal with a filter housing such that, in use, fluid being filtered through the filter element cannot bypass the filter element
wherein the seal member comprises both planar and non-planar portions that are configured to interact with matching planar and curved surfaces of the filter housing.