Internal seal arrangement for an axial flow centrifugal separator

Abstract

A crankcase ventilation system comprising a housing and a filter element assembly rotatably coupled to the housing. The filter element assembly comprises a first endcap, a second endcap spaced apart from the first endcap, a filter media pack coupled to the first endcap at a first end of the filter media pack and the second endcap at a second end of the filter media pack, and a seal member sealingly engaging the second endcap with the filter media pack along an outer perimeter region of the filter media pack. The filter media pack defines a plurality of axial flow channels extending between the first end and the second end.

Description

Atty. Dkt. No.: 137878-3376INTERNAL SEAL ARRANGEMENT FOR AN AXIAL FLOW CENTRIFUGAL SEPARATORCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 713,375, filed October 29, 2024, the entire contents of which are hereby incorporated by reference herein.TECHNICAL FIELD

[0002] The present disclosure relates generally to filters for use with internal combustion engine systems.BACKGROUND

[0001] During operation of an internal combustion engine, a fraction of combustion gases can flow out of the combustion cylinder and into the crankcase of the engine. These gases are generally referred to as “blowby” gases. The blowby gases include a mixture of aerosols, oils, and air. If vented directly to the ambient, the aerosols contained in the blowby gases can potentially harm the environment. Accordingly, the blowby gases are often routed out of the crankcase via a crankcase ventilation system. The crankcase ventilation system may pass the blowby gases through a coalescer (i.e., a coalescing filter element) to remove most or all of the aerosols and oils contained in the blowby gases. The filtered blowby gases (“clean” gases) are then either vented to the ambient (in open crankcase ventilation systems) or routed back to the air intake for the internal combustion engine for further combustion (in closed crankcase ventilation systems).

[0002] Some crankcase ventilation systems utilize rotating crankcase ventilation filter elements, for example, rotating coalescer elements that increase the filter efficiency of crankcase ventilation systems by rotating the coalescer element during filtering. In such designs, the contaminants (e.g., oil droplets suspended and transported by blowby gases) are separated at least in part by centrifugal separation techniques. Additionally, the rotation of the coalescer element can create a pumping effect, which reduces the pressure drop through the crankcase ventilation system.-1-4914-1071 -6773Atty. Dkt. No.: 137878-3376SUMMARY

[0003] At least one embodiment relates to a crankcase ventilation system including a housing and a filter element assembly rotatably coupled to the housing. The filter element assembly includes: a first endcap; a second endcap spaced apart from the first endcap; a filter media pack coupled to the first endcap at a first end of the filter media pack and the second endcap at a second end of the filter media pack, where the filter media pack defines a plurality of axial flow channels extending between the first end and the second end; and a seal member sealingly engaging the second endcap with the filter media pack along an outer perimeter region of the filter media pack.

[0004] In some embodiments, the second endcap includes: a base wall extending radially across at least a portion of the filter media pack; and a lip extending along an outer perimeter of the base wall, where the lip circumscribing at least a portion of the filter media pack at the second end, and where the seal member is disposed radially between the lip and the filter media pack.10005] In some embodiments, the housing includes: an inlet structured to receive blowby gases from an internal combustion engine; and an outlet structured to drain oil separated from the blowby gases. In some embodiments, the first endcap is disposed farther from the outlet than the second endcap.10006] In some embodiments, the seal member includes a wiper seal member disposed radially between the second endcap and the filter media pack.(0007] In some embodiments, the wiper seal member includes a flexible wiper configured to press radially against the filter media pack.10008] In some embodiments, the seal member is an axially facing seal member that engages the second endcap and the filter media pack along an axial direction relative to a central axis of the filter media pack.

[0009] In some embodiments, the seal member is over-molded onto the second endcap.

[0010] In some embodiments, the seal member includes a bead of an adhesive material disposed along the outer perimeter region of the filter media pack.-2-4914-1071 -6773Atty. Dkt. No.: 137878-3376

[0011] In some embodiments, the second endcap includes: a base wall; and a lip extending axially from an outer periphery of the base wall. In some embodiments, an axial height of the seal member relative to a central axis of the filter element assembly is less than an axial height of the lip.[00121 At least one embodiment relates to a rotating crankcase ventilation filter element assembly including: a hub defining a central channel configured to receive a motor shaft therein for powering rotation of the hub; a filter media pack wound around the hub; a first endcap coupled to the hub and positioned on a first end of the filter media pack, where the first endcap including a sidewall extending axially from an outer periphery thereof; a second endcap coupled to the hub and positioned on a second end of the filter media pack opposite the first end; and a seal member. The second endcap includes: a base wall extending radially across at least a portion of the filter media pack; and a lip extending axially from an outer periphery of the base wall, where the lip and the sidewall together define an oil drain port, and the lip is spaced apart from the filter media pack by a radial gap. The seal member is sealingly engaged with the filter media pack and the second endcap proximate the radial gap-10013] In some embodiments, the seal member includes a wiper seal member having a wiper that extends radially inwardly from the lip at an intermediate position between opposing ends of the lip that engages the filter media pack.

[0014] In some embodiments, the wiper is tapered so that a height of the wiper decreases moving in a radial direction toward the filter media pack.[00151 In some embodiments, the rotating crankcase ventilation filter element assembly further includes an inner ring that engages the filter media pack along an axial direction proximate to an outer perimeter of the filter media pack, where the seal member includes a bead of an adhesive material disposed within the radial gap.|0016] In some embodiments, an axial height of the seal member relative to a central axis of the second endcap is less than an axial height of the lip.-3-4914-1071 -6773Atty. Dkt. No.: 137878-3376

[0017] In some embodiments, the second endcap defines a seal member opening extending therethrough, and the seal member is over-molded onto the second endcap through the seal member opening.

[0018] In some embodiments, the filter media pack includes a plurality of filter media layers arranged along a radial direction and defining a plurality of axial flow channels extending therethrough.[00191 In some embodiments, the base wall defines a circumferential groove extending about a central axis of the base wall, and the seal member is disposed within the circumferential groove axially between the filter media pack and the base wall.|0020] At least one embodiment relates to a method of manufacturing a rotating crankcase ventilation filter element assembly. The method includes: positioning a filter media pack around a hub; coupling a first endcap to the hub on a first end of the filter media pack; and coupling a second endcap to the hub on a second end of the filter media pack opposite the first end so that: a base wall of the second endcap extends radially across at least a portion of the filter media pack; a lip of the second endcap that extends axially from an outer periphery of the base wall defines an oil drain port with a sidewall of the first endcap that extends axially from an outer periphery of the first endcap; and the lip is spaced apart from the filter media pack by a radial gap. The method further includes sealingly engaging a seal member with the second endcap and the filter media pack proximate the radial gap.

[0021] In some embodiments, sealingly engaging the seal member with the second endcap and the filter media pack includes positioning the seal member within the radial gap such that the seal member extends from the lip to the filter media pack.

[0022] In some embodiments, sealingly engaging the seal member with the second endcap and the filter media pack includes dispensing an adhesive material into the radial gap so that a height of the adhesive material within the radial gap is less than a height of the lip.BRIEF DESCRIPTION OF THE FIGURES-4-4914-1071 -6773Atty. Dkt. No.: 137878-3376

[0023] 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.

[0024] FIG. l is a perspective cross-sectional view of a crankcase ventilation system, according to an embodiment.10025] FIG. 2 is a side cross-sectional view of a filter element for use in a crankcase ventilation system, according to an embodiment.

[0026] FIG. 3 is a side cross-sectional view of a sealing interface of the filter element of FIG. 2, between a filter media pack and an endcap of the filter element, according to an embodiment.

[0027] FIG. 4 is a side cross-sectional view of a sealing interface of a filter element for a crankcase ventilation system, according to another embodiment.

[0028] FIG. 5A is a side cross-sectional view of a sealing interface of a filter element for a crankcase ventilation system, according to still another embodiment.10029] FIG. 5B is a side cross-sectional view of a filter element for a crankcase ventilation system, according to another embodiment.

[0030] FIG. 5C is a side cross-sectional view of a sealing interface of the filter element of FIG. 5B.[00311 FIG. 6 is a side cross-sectional view of a sealing interface of a filter element for a crankcase ventilation system, according to still another embodiment.

[0032] FIG. 7 is a chart showing separation efficiency for a crankcase ventilation system in various different configurations.

[0033] FIG. 8 is a chart showing separation efficiency as a function of particle size for the various arrangements of the crankcase ventilation system in FIG. 7.-5-4914-1071 -6773Atty. Dkt. No.: 137878-3376

[0034] FIG. 9 is a flow diagram of a method of manufacturing a rotating crankcase ventilation filter element assembly, according to an embodiment.|0035] 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 spirit or 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.DETAILED DESCRIPTION

[0036] Embodiments described herein relate generally to inner seal arrangements of a filter element for use in a rotating crankcase ventilation system, and in particular, a filter element that includes an inner seal member that is structured to prevent blowby gases from bypassing an interface between an endcap at an upstream side of the filter element and the filter media pack.Overview[0037J Rotating crankcase ventilation filter elements may include a corrugated and / or wound axial filter media layers, for example, a filter media layer wound into a roll to form the filter media pack. The blowby gases flow from an upstream side to a downstream side of the filter media pack and are generally sealed via a mechanical interference between the filter media pack and an endcap located at the upstream side of the filter element. The interference and / or contact seal can help reduce blowby gasses to the downstream side of the filter element. However, the seal provided by the interference may be imperfect in certain scenarios. For example, the geometry of the wound filter media pack can vary along its outer perimeter, forming a “cam shape” that can prevent continuous contact between the filter media pack and the endcap. Additionally, dimensional tolerances and vertical tolerance stack up can result in a small gap between the filter media pack and the endcap in some instances, which can limit separation of particles below 0.3 microns.-6-4914-1071 -6773Atty. Dkt. No.: 137878-3376

[0038] Referring generally to the figures, embodiments herein relate to a filter element for a rotating crankcase ventilation system that includes a seal member that prevents or substantially prevents leakage of blowby gases between the outer perimeter of the filter media pack and the endcap at an upstream side of the filter element, while still allowing draining of separated oil through a sidewall of the filter element.

[0039] Referring to FIG. 1, a cross-sectional view of a crankcase ventilation system 10 is shown according to an example embodiment. The crankcase ventilation system 10 includes a housing 12 and a rotating crankcase ventilation filter element assembly (e.g., a rotating coalescer element), shown as filter element 16, coupled to the housing 21. The filter element 16 includes a first endcap 120; a second endcap 130 spaced apart from the first endcap 120; and a filter media pack 110. The filter media pack 110 is coupled to the first endcap 120 at a first end 121 of the filter media pack 110 and the second endcap 130 at a second end 123 of the filter media pack 110. The filter media pack 110 defines multiple axial flow channels, shown as axial flow channels 113, extending between the first end 121 and the second end 123. A seal member 144 sealingly engages the second endcap 130 with the filter media pack 110 along an outer perimeter 145 of the filter media pack 110.

[0040] The rotating crankcase ventilation filter element assembly (e.g., a rotating coalescer element), shown as the filter element 16 is driven by a pressurized fluid or a motor. The crankcase ventilation system 10 generally processes blowby gases received from an internal combustion engine crankcase to remove aerosols, oils, and other particulate contained in the crankcase blowby gases. The crankcase ventilation system 10 generally includes a housing 12 having an inlet 14 that receives crankcase blowby gases to be filtered (e.g., from a crankcase of an internal combustion engine), a central compartment having the filter element 16 installed therein, and an outlet 18 that provides filtered blowby gases to the internal combustion engine (in a closed crankcase ventilation system) or to the ambient (e.g., the environment surrounding the internal combustion engine system, in an open crankcase ventilation system).|004l] In some embodiments, and as shown in FIGS. 1-4, the filter element 100 includes a hub 112, the filter media pack 110, the first endcap 120, the second endcap 130, and the seal member 144. The hub 112 defines a central channel 114 that is configured to receive a motor shaft, shown as a central shaft 50, therein for powering rotation of the hub -7-4914-1071 -6773Atty. Dkt. No.: 137878-3376112. The filter media pack 110 is wound around the hub 112. The first endcap 120 is coupled to the hub 112 and is positioned on a first end 121 of the filter media pack 110. The first endcap 120 includes a sidewall, shown as a first sidewall 124, extending axially away from an outer periphery thereof. The second endcap 130 is coupled to the hub 112 and is positioned on a second end 123 of the filter media pack 110 opposite the first end 121. The second endcap 130 includes a base wall 138 extending radially across at least a portion of the filter media pack 110, and a lip 136 extending axially from an outer periphery of the base wall 138. The lip 136 and the first sidewall 124 together define an oil drain port 126. The lip 136 is spaced apart from the filter media pack 110 by a radial gap 146. The seal member 144 is sealingly engaged with the filter media pack 110 and the second endcap 130 proximate the radial gap 146 (e.g., within or adjacent to, etc.).

[0042] During operation of the crankcase ventilation system 10, blowby gases 11 enter the housing 12 through the inlet 14. The blowby gases are directed to the central compartment where the blowby gases flow through the filter element 16 in an inside-out manner. In an alternate arrangement, the crankcase ventilation system 10 can be configured to have an outside-in flow arrangement. The filter element 16 may be coupled to a central shaft 50 that transfers rotation to the filter element 16. The central shaft 50 may be rotationally driven by a turbine that is rotated by a jet of oil generated by an oil pump. The turbine may be an impulse turbine. In other embodiments, the central shaft 50 may be driven by an electric motor or by another driver. As the filter element 16 rotates, the filter element 16 (e.g., a rotating coalescer element) separates oil, aerosols, and other contaminants contained in the blowby gases. The separated contaminants drain from the housing 12 through a drain and return to the engine crankcase sump. The filter element 16 may include a first endcap, a second endcap, and a filter media (e.g., a separating device), as will be described with reference to FIG. 2.

[0043] In various embodiments, the filter media may comprise a corrugated and wound filter media configured for axial flow therethrough. For example, the filter media may include a plurality of filter media layers along a radial direction that are formed by winding or rolling a single layer or form of filter media into a cylindrical shape. A thickness of the filter media form, which may include multiple individual media and / or support layers, may be approximately 0.35 mm (e.g., 0.3 mm to 0.4 mm, etc.). The media layers within the-8-4914-1071 -6773Atty. Dkt. No.: 137878-3376 media form may include a filter media layer and support layer made from a stainless steel material, which can increase strength of the filter media pack relative to an aluminum support layer, and can allow for the use of thinner filter media material (e.g., more channels across each filter media layer, etc.).[0044 | The inlet 14 of the housing 12 receives crankcase blowby gases 11 to be filtered (e.g., from a crankcase of an internal combustion engine, including aerosols, oils, and other particulate contained in the crankcase blowby gases). The housing 12 defines a central compartment housing the filter element 16 therein. The filter element 16 removes aerosols, oils, and other particulate from the blowby gases 11 and that provides filtered blowby gases 13, via the outlet 18 to the internal combustion engine (in a closed crankcase ventilation system) or to the ambient (in an open crankcase ventilation system).

[0045] During operation of the crankcase ventilation system 10, blowby gases 11 enter the housing 12 through the inlet 14. In the embodiment of FIG. 1, the blowby gases 11 are directed to the central compartment where the blowby gases 11 flow axially through the filter element 16, as indicated by the flow direction arrows. The filter element 16 may be coupled to a central shaft 50 that transfers rotation to the filter element 16. In some embodiments, the central shaft 50 is rotationally driven by a motor 22 disposed in a portion of a cover 20 coupled to the housing 12, which extends into the internal volume defined by the housing 12. As the filter element 16 rotates, the filter element 16 (e.g., a rotating coalescer element) separates oil, aerosols, and other contaminants contained in the blowby gases. The separated contaminants drain from the housing 12 (e.g., through a drain) and return to an engine crankcase sump.

[0046] Referring to FIG. 2, a rotating crankcase ventilation element, shown as filter element 100, that may be used as the filter element of FIG. 1 is shown, according to an example embodiment. The filter element 100 may be used to filter a fluid, for example air, fuel, air-fuel mixture, blowby gases or any other fluids used in an internal combustion engines. The filter element 100 includes a filter media pack 110, a hub 112, a first endcap 120 (e.g., a top endcap), and a second endcap 130 (e.g., a bottom endcap) coupled to the first endcap 120. In the embodiment of FIG. 2, the filter element 100 is configured to filter crankcase blowby gases received from the internal combustion engine crankcase, for example, to remove aerosols, oils, and other particulate contained in the crankcase blowby -9- 4914-1071 -6773Atty. Dkt. No.: 137878-3376 gases. In various embodiments, the filter element 100 is mounted or coupled to the central shaft 50. The central shaft 50 may be operatively coupled to a motor (e.g., a DC motor) or turbine and configured to rotate the filter element 100, for example, to facilitate centrifugal separation of aerosols, oils, water, etc. from the blowby gases (see also FIG. 1).[0047| The filter media pack 110 is positioned along a longitudinal axis (e.g., a central axis 111) of the filter element 100. In some embodiments, the filter media pack 110 includes a corrugated and wound filter media configured for axial flow therethrough (e.g., so that flow passes through the filter media pack 110 along a substantially axial direction that extends parallel to the central axis 111). In some embodiments, the filter media pack 110 includes a plurality of filter media layers along a radial direction that are formed by winding or rolling a single layer or form of filter media pack 110 into a cylindrical shape, as described above. In various embodiments, the filter media pack 110 may be configured for axial flow therethrough. For example, the corrugations of the plurality of filter media layers (which may also be referred to as repeating layers) may define axial flow channels 113 therebetween so as to allow axial flow of the gas through the axial flow channels 113.[0048| As previously described, in some embodiments, the filter element 100 is configured to be mounted on the central shaft (e.g., the shaft 50 of FIG. 1) that is configured to rotate the filter element 100. The rotation may cause oil, particles or other contaminants included in the fluid (e.g., blowby gases) flowing through the channels formed between the plurality of layers of the filter media pack 110 to coalesce. The coalesced droplets are then removed (e.g., drained) from the filter element 100.

[0049] In some embodiments, the filter media pack 110 is wound around the hub 112, about an outer periphery of the hub 112. The hub 112 defines a central channel 114 that is configured to receive the central shaft for mounting the hub 112 and thereby, the filter element 100 on the central shaft. The hub 112 also defines at least one hub through hole. The at least one hub through hole is structured to axially align with corresponding through holes defined in a first coupling portion of the first endcap 120 and a second coupling portion of the second endcap 130 such that the portion / s of the hub 112 defining the at least one hub through hole is interposed between the first coupling portion and the second coupling portion. A coupling member (e.g., a screw, a bolt, a pin, a rivet, etc.) may be inserted through the through holes defined in the first coupling portion, the second coupling -10-4914-1071 -6773Atty. Dkt. No.: 137878-3376 portion, and the hub through hole so as to couple the first endcap 120 to the second endcap 130 and secure the hub 112 and therefore, the filter media pack 110 therebetween.10050] The first endcap 120 (an upper endcap as shown in FIG. 2, a downstream endcap, etc.) is positioned on a filter media first end 121 (which may also be referred to as a first end, a top end, and / or a first axial end) of the filter media pack 110. The first endcap 120 is coupled to the filter media pack 110 and the hub 112. The first endcap 120 may include a first endcap main body, and a first sidewall 124 extending axially from an outer periphery of the first endcap main body towards the second endcap 130 such that the first endcap 120 defines a portion of an inner volume within which at least a portion of the filter media pack 110 and the hub 112 is disposed. In some embodiments, a plurality of radial flow channels are defined in the first endcap 120 to allow dirty fluid to enter the filter media pack 110 therethrough, or alternatively, allow clean fluid to exit the filter element 100. The first endcap 120 may be formed from a strong and rigid material, for example plastics (e.g., polypropylene, high density polyethylene, polyvinyl chloride, etc.), metals (e.g., aluminum, stainless steel, etc.), polymers (e.g., reinforced rubber, silicone) or another material.[00511 The second endcap 130 (a lower endcap as shown in FIG. 2, an upstream endcap, etc.) is positioned on a filter media second end 123 (which may also be referred to as a second end, a bottom end, and / or a second axial end) of the filter media pack 110 opposite the filter media first end 121. The second endcap 130 is coupled to the filter media pack 110 and the hub 112. In some embodiments, the second endcap 130 is disposed adjacent the outlet (e.g., from the outlet of the housing that is structured to drain oil separated from the blowby gases), so that the first endcap 120 is disposed farther from the outlet than the second endcap 130. Such an arrangement can further improve oil separation performance by maintaining the oil drain away from areas in which oil aerosol may still be present. The second endcap 130 is coupled to the first endcap 120 such that the first endcap 120 and the second endcap 130 define the internal volume within which the filter media pack 110 is disposed.Inner Seal Arrangements for a Rotating Coalescing Filter Element

[0052] Referring to FIG. 3, the second endcap 130 includes a base wall 138 (which may also be referred to as a base), which may include a panel; a second sidewall, shown as lip-11-4914-1071 -6773Atty. Dkt. No.: 137878-3376140; and an inner ring 142. The base wall 138 extends radially across at least a portion of the filter media pack 110 and covers an end of the filter media pack 110 (e.g., covers the filter media second end 123 of the filter media pack 110).

[0053] The lip 136 projects axially from an outer periphery of the second endcap 130 at a location disposed radially outwards of the filter media pack 110. The lip 140 extends axially away from the second endcap 130 and towards the first endcap 120 (see also FIG. 2). The lip extends along an outer perimeter of the base wall 138. The lip 140 is spaced radially apart from the filter media pack 110 by a radial gap 146. In some embodiments, the lip 136 is configured to engage a proximate end (e.g., a lower end as shown in FIG. 2) of the first sidewall 124, for example, snap-lock to, friction fit with, or generally, contact the first sidewall 124 so as to define an enclosed volume within which the filter media pack 110 is disposed. The lip 136 circumscribes at least a portion of the filter media pack 110 at the media pack second end 123.10054] The inner ring 142 protrudes from the base wall 138 toward the filter media pack 110 along a substantially axial direction that is parallel to the central axis 111. In some embodiments, and as shown, the inner ring 142 is a circumferential protrusion that extends in a circumferential direction about the base wall 138. In some embodiments, the inner ring 142 is engageable with the filter media pack 110 in an axial direction along or proximate an outer diameter of the filter media pack 110. A height of the inner ring 142 along an axial direction is less than a height of the lip 136. The second endcap 130 may be formed from a strong and rigid material, for example plastics (e.g., polypropylene, high density polyethylene, polyvinyl chloride, etc.), metals (e.g., aluminum, stainless steel, etc.), polymers (e.g., reinforced rubber, silicone) or another material.10055] Referring to FIG. 4, the filter element 100 includes a seal member 144 (e.g., an inner seal member, a second endplate seal member, etc.) that is configured to sealingly engage the second endcap 130 with the filter media pack 110 at the second end 123 of the filter media pack 110. The seal member 144 sealingly engages the second endcap 130 with the filter media pack 110 along an outer perimeter 145 of the filter media pack 110. In some embodiments, the filter element 100 defines a radial gap 146 between the lip 136 and the filter media pack 110 that is sized to receive the seal member 144 therein. The seal member-12-4914-1071 -6773Atty. Dkt. No.: 137878-3376 is sealingly engaged with the filter media pack 110 to substantially prevent bypass of blowby gases through the radial gap 146.10056] In the embodiment of FIG. 4, the seal member 144 is a continuous bead of an adhesive and / or elastomeric material that is disposed (e.g., poured, potted, etc.) within the radial gap 146 and below the oil drain port defined by the first sidewall 124 and the second endcap 130 (e.g., the lip 136). The seal member 144 conforms to the geometry along the outer perimeter 145 (e.g., outer perimeter region, etc.) of the filter media pack 110. Beneficially, positioning the adhesive and / or elastomeric material of the seal member along at least a portion of the outer radial surface of the filter media pack 110 at the second end 123 substantially prevents blocking of the axial flow channels 113 (see FIG. 1) through the filter media pack 110, while at the same time reducing the risk of leakage / bypass through the interface between the filter media pack 110 and the second endcap 130. In some embodiments, a height 148 of the seal member 144 (e.g., an axial height substantially parallel to the central axis 111) is less than a height 150 of the lip 136, which can reduce the risk of blocking an oil drain port 126 defined by (e.g., between) the lip 136 and the first sidewall 124 (see FIG. 3).(0057] The arrangement of the seal member may be different in various embodiments. For example, referring to FIG. 5 A, a filter element 200 is shown that includes a radially facing seal member, shown as seal member 244, that is inserted into a radial gap 246 defined between a filter media pack 210 and a lip 236 of a second endcap 230. The seal member 244 is engageable with the filter media pack 210 along a radial direction relative to a central axis of the filter media pack 210 (and the central axis of the second endcap 230).

[0058] In the embodiment of FIG. 5 A, the seal member 244 includes a wiper seal member having a wiper 247 (e.g., a flexible wiper) that extends radially inwardly from the lip 236 at an intermediate position between opposing ends of the lip 236 (e.g., between a proximate / lower end of the lip 236 and a distal / lower end of the lip 236 as shown in FIG. 5A). Such an arrangement can provide greater surface area for contact between the lip 236 and the filter media pack 210. The wiper 247 may be a flexible member that is configured to press radially against the filter media pack 210 to sealingly engage the second endcap 230 to the filter media pack 210. In the embodiment of FIG. 5 A, the wiper seal member also includes a seal member body 245 that is configured to couple the wiper seal member to the -13-4914-1071 -6773Atty. Dkt. No.: 137878-3376 second endcap 230. The wiper 247 is disposed at an end of the seal member body 245 and extends radially away from the seal member body 245. In some embodiments, the wiper 247 is tapered so that a height 249 of the wiper 247 decreases (e.g., to a tip of the wiper 247) moving in a radial direction toward the filter media pack (e.g., so that the height 249 of the wiper 247 near the filter media is less than the height 249 of the wiper 247 away from the filter media). In some embodiments, the seal member body 245 is secured to the second endcap 230 using an adhesive material. In other embodiments, the seal member body 245 may be embedded into the second endcap 230.

[0059] In some embodiments, the wiper seal member is over-molded onto the lip 236 and / or onto another part of the second endcap 230. For example, referring to FIGS. 5B-5C, a filter element 250 is shown that includes a seal member 252 that is overmolded onto the second endcap 254. The second endcap 254 defines an inner ring 255 that engages the filter media pack along an axial direction proximate to an outer perimeter of the filter media pack. The second endcap 254 also includes a lip 257 and a seal support ledge 256 extending between the lip 257 toward the inner ring 255. In the embodiment of FIG. 5B, the seal support ledge 256 is spaced radially apart from the inner ring 255 and the lip 257 and has a height along the axial direction that is greater than a height of the inner ring 255 (but less than the lip 257). In other embodiment, the arrangement of the seal support ledge 256 may be different. The second endcap 254 defines a seal member opening 258 (e.g., a through- hole opening) extending through the seal support ledge 256 from a first side of the second endcap 254 through a second side of the second endcap 254.

[0060] Referring to FIG. 5C, the seal member 252 includes a seal member body 260 and a wiper 262 that extends from an end of the seal member body 260 in a substantially radial direction toward the filter media pack. In some embodiments, the seal member body 260 is overmolded onto the second endcap at the seal member opening 258. The seal member 252 sealingly engages (i) the second endcap at the seal member body 260, and (ii) the filter media pack at the wiper 262. In other embodiments, the wiper seal member is formed as a separate piece that is inserted into the seal member opening 258 and / or into a radial gap between the lip 257 and the filter media pack. Beneficially, the combination of the seal member 252 and the inner ring 255 can further reduce the risk of bypass between the filter element 250 and the second endcap 254.-14-4914-1071 -6773Atty. Dkt. No.: 137878-3376

[0061] The shape of the seal member may be different in various embodiments. For example, in some embodiments, the seal member includes an O-ring that is disposed in a groove along an inner surface of the lip 236 and that protrudes radially from the lip 236 toward the filter media pack 210 and engages an outer radially facing surface of the filter media pack 210.

[0062] Referring to FIG. 6, a filter element 300 is shown that includes an axially facing seal member, shown as seal member 344, that is configured to press against a filter media pack 310 at an outer diameter of the filter media pack 310 along an axial direction relative to a central axis 311 of the filter media pack 310. In the embodiment of FIG. 6, the seal member 344 is an O-ring that is positioned in a groove 313 defined by a base wall of the second endcap 330 that faces toward the filter media pack 310 in an axial direction. A height of the seal member 344 is greater than a height of the groove 313. In some embodiments, the inner ring defines at least a portion of the groove 313. In such embodiments, the inner ring may be configured to limit axial compression of the seal member 344. In some embodiments, the groove is a circumferential groove that extends in a circumferential direction about the central axis of the base wall. In other embodiments, the seal member may be an embedded seal member that is at least partially embedded into the material of the second endcap 330. In the embodiment of FIG. 6, the seal member 344 is disposed axially between the filter media pack 310 and the second endcap 330 and sealingly engages the base wall of the second endcap 330 with the filter media pack 310.

[0063] It should be understood that a variety of different types of seal members (e.g., radially facing, axially facing, gaskets, O-rings, etc.) may be used along the outer diameter of the filter media pack to prevent leakage of blowby gasses through the second media end of the filter media pack. The seal member may be integrally formed with at least a portion of the second endcap (e.g., overmolded, embedded, etc.) or formed separately from the second endcap (e.g., an O-ring, etc.). It should be understood that the filter element may include any combination of seal members described herein.10064] Referring to FIG. 7, a chart 400 of separation efficiency at a fixed flow rate of bypass gasses for various implementations of the rotating crankcase ventilation system is shown, according to an example embodiment. As shown, incorporating a seal member, as indicated at 402, significantly increases the separation efficiency of the rotating crankcase -15-4914-1071 -6773Atty. Dkt. No.: 137878-3376 ventilation system (and can also reduce variability in the overall separation efficiency, in some instances). In some embodiments, and as shown, incorporating the seal member increases the separation efficiency to greater than 99.9 % (e.g., 99.99%, etc.).

[0065] FIG. 8 is a chart 500 showing separation efficiency as a function of particle size for the various arrangements of the crankcase ventilation system in FIG. 7. Data points 502 correspond to separation efficiency data for a filter element that does not include an inner seal member. Data points 504 correspond to separation efficiency data for a filter element that includes an inner seal member and that is rotated at higher speed than the arrangement of data points 502.

[0066] Referring to FIG. 9, a method 600 of manufacturing a rotating crankcase ventilation filter element assembly is shown, according to an example embodiment. The method 600 may be used to form any one of the filter elements described herein.

[0067] The method 600 includes positioning a filter media pack (e.g., the filter media pack around a hub; coupling a first endcap to the hub on a first end of the filter media pack; coupling a second endcap to the hub on a second end of the filter media pack opposite the first end so that: (i) a base wall of the second endcap extends radially across at least a portion of the filter media pack; (ii) a lip of the second endcap that extends axially from an outer periphery of the base wall defines an oil drain port with a sidewall of the first endcap that extends axially from an outer periphery of the first endcap; and (iii) the lip is spaced apart from the filter media pack by a radial gap. The method 600 also includes sealingly engaging a seal member with the second endcap and the filter media pack proximate the radial gap.[0068 [ The method 900 includes positioning the filter media pack around the hub, at operation 902. In some embodiments, operation 902 includes winding a filter media form that includes multiple layers stacked on top on one another in a spiral arrangement around the hub and so that the filter media pack defines a plurality of axial flow channels extending therethrough.

[0069] The method 900 also includes coupling a first endcap to the hub on the first end of the filter media pack, at operation 904. In some embodiments, operation 904 includes forming a sidewall that extends axially away from a base portion of the first endcap at an -16-4914-1071 -6773Atty. Dkt. No.: 137878-3376 outer perimeter of the base portion. In some embodiments, operation 904 includes aligning the first endcap (e.g., an opening of the first endcap) with the hub and axially aligning the first endcap with the filter media pack (e.g., so that the sidewall circumscribes at least a portion of the filter media pack. In some embodiments, operation 904 includes inserting a fastener through the first endcap and into the hub to secure the first endcap to the hub.[00701 The method 900 further includes coupling a second endcap to the hub on the second end of the filter media pack, at operation 906. In some embodiments, operation 906 includes at least one of forming the second endcap by forming the base wall; forming a lip onto the base wall that extends axially away from the outer periphery of the base wall; and / or forming an inner ring that extends axially away from the base wall and that is spaced radially apart from the lip at a location adjacent to an outer perimeter region of the filter media pack.

[0071] In some embodiments, operation 906 includes positioning the second endcap with respect to the filter media pack and the first endcap so that: (i) the base wall of the second endcap extends radially across at least a portion of the filter media pack; (ii) a lip of the second endcap defines an oil drain port with the sidewall of the first endcap; and (iii) the lip is spaced apart from the filter media pack by a radial gap (e.g., so that the lip circumscribes at least a portion of the filter media pack at the second end).10072] The method 900 further includes sealingly engaging the seal member with the second endcap and the filter media pack proximate the radial gap, at operation 908. In some embodiments, operation 908 includes positioning the seal member within the radial gap, for example, so that the seal member extends form the lip to the filter media pack. In some embodiments, operation 908 includes dispensing an adhesive material into the radial gap so that a height of the adhesive material within the radial gap is less than a height of the lip. In some embodiments, operation 908 includes positioning an axially facing seal member within a circumferential groove of the second endcap at a location adjacent to an outer perimeter of the filter media pack. In such embodiments, operation 908 may include axially engaging the second end of the filter media pack with the axially facing seal member, for example, so that the axially facing seal member is disposed axially between the filter media pack and the second endcap.-17-4914-1071 -6773Atty. Dkt. No.: 137878-3376

[0073] 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).[0074 | 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.

[0075] 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.[0076[ 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.-18-4914-1071 -6773Atty. Dkt. No.: 137878-3376

[0077] While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any embodiment or of what may be claimed, but rather as descriptions of features specific to particular implementations of particular embodiments. Certain features described in this specification in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.4914-1071 -6773

Claims

Atty. Dkt. No.: 137878-3376WHAT IS CLAIMED IS:

1. A crankcase ventilation system comprising: a housing; and a filter element assembly rotatably coupled to the housing, the filter element assembly comprising: a first endcap; a second endcap spaced apart from the first endcap; a filter media pack coupled to the first endcap at a first end of the filter media pack and the second endcap at a second end of the filter media pack, the filter media pack defining a plurality of axial flow channels extending between the first end and the second end; and a seal member sealingly engaging the second endcap with the filter media pack along an outer perimeter region of the filter media pack.

2. The crankcase ventilation system of claim 1, wherein the second endcap comprises: a base wall extending radially across at least a portion of the filter media pack; and a lip extending along an outer perimeter of the base wall, the lip circumscribing at least a portion of the filter media pack at the second end, wherein the seal member is disposed radially between the lip and the filter media pack.

3. The crankcase ventilation system of claim 1, wherein the housing comprises: an inlet structured to receive blowby gases from an internal combustion engine; and an outlet structured to drain oil separated from the blowby gases, wherein the first endcap is disposed farther from the outlet than the second endcap.-20-4914-1071-6773Atty. Dkt. No.: 137878-33764. The crankcase ventilation system of claim 1, wherein the seal member comprises a wiper seal member disposed radially between the second endcap and the filter media pack.

5. The crankcase ventilation system of claim 4, wherein the wiper seal member comprises a flexible wiper configured to press radially against the filter media pack.

6. The crankcase ventilation system of claim 1, wherein the seal member is an axially facing seal member that engages the second endcap and the filter media pack along an axial direction relative to a central axis of the filter media pack.

7. The crankcase ventilation system of claim 1, wherein the seal member is overmolded onto the second endcap.

8. The crankcase ventilation system of claim 1, wherein the seal member comprises a bead of an adhesive material disposed along the outer perimeter region of the filter media pack.

9. The crankcase ventilation system of claim 1, wherein the second endcap comprises: a base wall; and a lip extending axially from an outer periphery of the base wall, wherein an axial height of the seal member relative to a central axis of the filter element assembly is less than an axial height of the lip.-21-4914-1071-6773Atty. Dkt. No.: 137878-337610. A rotating crankcase ventilation filter element assembly comprising: a hub defining a central channel configured to receive a motor shaft therein for powering rotation of the hub; a filter media pack wound around the hub; a first endcap coupled to the hub and positioned on a first end of the filter media pack, the first endcap comprising a sidewall extending axially from an outer periphery thereof; a second endcap coupled to the hub and positioned on a second end of the filter media pack opposite the first end, the second endcap comprising: a base wall extending radially across at least a portion of the filter media pack; and a lip extending axially from an outer periphery of the base wall, the lip and the sidewall together defining an oil drain port, the lip spaced apart from the filter media pack by a radial gap; and a seal member sealingly engaged with the filter media pack and the second endcap proximate the radial gap.

11. The rotating crankcase ventilation filter element assembly of claim 10, wherein the seal member comprises a wiper seal member having a wiper that extends radially inwardly from the lip at an intermediate position between opposing ends of the lip that engages the filter media pack.

12. The rotating crankcase ventilation filter element assembly of claim 11, wherein the wiper is tapered so that a height of the wiper decreases moving in a radial direction toward the filter media pack.

13. The rotating crankcase ventilation filter element assembly of claim 10, further comprising an inner ring that engages the filter media pack along an axial direction proximate to an outer perimeter of the filter media pack, wherein the seal member comprises a bead of an adhesive material disposed within the radial gap.-22-4914-1071-6773Atty. Dkt. No.: 137878-337614. The rotating crankcase ventilation filter element assembly of claim 10, wherein an axial height of the seal member relative to a central axis of the second endcap is less than an axial height of the lip.

15. The rotating crankcase ventilation filter element assembly of claim 10, wherein the second endcap defines a seal member opening extending therethrough, the seal member overmolded onto the second endcap through the seal member opening.

16. The rotating crankcase ventilation filter element assembly of claim 10, wherein the filter media pack comprises a plurality of filter media layers arranged along a radial direction and defining a plurality of axial flow channels extending therethrough.

17. The rotating crankcase ventilation filter element assembly of claim 10, wherein the base wall defines a circumferential groove extending about a central axis of the base wall, the seal member disposed within the circumferential groove axially between the filter media pack and the base wall.

18. A method of manufacturing a rotating crankcase ventilation filter element assembly, the method comprising: positioning a filter media pack around a hub; coupling a first endcap to the hub on a first end of the filter media pack; coupling a second endcap to the hub on a second end of the filter media pack opposite the first end so that: a base wall of the second endcap extends radially across at least a portion of the filter media pack; a lip of the second endcap that extends axially from an outer periphery of the base wall defines an oil drain port with a sidewall of the first endcap that extends axially from an outer periphery of the first endcap; and the lip is spaced apart from the filter media pack by a radial gap; and-23-4914-1071-6773Atty. Dkt. No.: 137878-3376 sealingly engaging a seal member with the second endcap and the fdter media pack proximate the radial gap.

19. The method of claim 18, wherein sealingly engaging the seal member with the second endcap and the fdter media pack comprises positioning the seal member within the radial gap such that the seal member extends from the lip to the fdter media pack.

20. The method of claim 18, wherein sealingly engaging the seal member with the second endcap and the fdter media pack comprises dispensing an adhesive material into the radial gap so that a height of the adhesive material within the radial gap is less than a height of the lip.-24-4914-1071-6773

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