Crankcase ventilation filter assembly with rotary and stationary filter elements

Abstract

A crankcase ventilation filter assembly includes a housing. The crankcase ventilation filter assembly includes a rotary filter element positioned at least partially within a housing. The rotary filter element includes a first filter media configured to rotate within the housing and configured for axial flow of fluid through the first filter media. The crankcase ventilation filter assembly includes a stationary filter element positioned at least partially within a housing. The stationary filter element includes a second filter media positioned radially outward from the first filter media and configured for radially flowing gas through the second filter media from inside to outside. An air gap is defined between the second filter media and the housing such that fluid exiting the second filter media flows through the air gap and out of the crankcase ventilation filter assembly.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 540,731, filed September 27, 2023. The contents of that application are incorporated herein by reference in their entirety. Technical Field

[0002] This disclosure generally relates to filters for use with internal combustion engine systems. background

[0003] During the operation of an internal combustion engine, some combustion gases can flow out of the combustion cylinders and into the engine's crankcase. These gases are commonly referred to as "blowby gases." Blowby gases consist of a mixture of aerosols, oil, and air. If released directly into the environment, the aerosols contained in the blowby gases can be harmful. Therefore, blowby gases are typically guided out of the crankcase via a crankcase ventilation system. The crankcase ventilation system allows the blowby gases to pass through a coalescer (i.e., a coalescing filter element) to remove most of the aerosols and oil contained in the blowby gases. The filtered blowby gases ("clean" gases) are then either released into the environment (in the case of an open crankcase ventilation system) or guided back to the internal combustion engine's air intake for further combustion (in the case of a closed crankcase ventilation system).

[0004] Some crankcase ventilation systems utilize rotary crankcase ventilation filter elements, such as rotary coalescer elements, which improve the filtration efficiency of the crankcase ventilation system by rotating the coalescer element during filtration. In rotary coalescer elements, contaminants (e.g., leaky gas suspensions and transported oil droplets) are separated at least partially by centrifugal separation technology. Furthermore, the rotation of the coalescer element can generate a pumping effect, which reduces the pressure drop across the crankcase ventilation system. Overview

[0005] The embodiments described herein generally relate to crankcase ventilation filter assemblies comprising a rotating filter element having axial flow filter media and a stationary filter element positioned around the rotating filter element having radial flow filter media. The radial flow filter media facilitates radial flow from the inside out.

[0006] In one set of embodiments, the crankcase ventilation filter assembly includes a housing. The crankcase ventilation filter assembly includes a rotary filter element at least partially positioned within the housing. The rotary filter element includes a first filter medium configured to rotate within the housing and constructed to allow axial flow of fluid through the first filter medium. The crankcase ventilation filter assembly includes the rotary filter element and a stationary filter element, both at least partially positioned within the housing. The stationary filter element includes a second filter medium radially outwardly positioned from the first filter medium and constructed to allow radial flow of gas through the second filter medium. The radial flow of gas can be an inward-to-outward radial flow (e.g., gas flows from a first position to a second position, where the first position is radially inward relative to the second position). An air gap is defined between the second filter medium and the housing, such that fluid exiting the second filter medium flows through the air gap and out of the crankcase ventilation filter assembly.

[0007] In another embodiment, the filter assembly includes a housing, a rotary filter element at least partially positioned within the housing, and a stationary filter element at least partially positioned within the housing. The rotary filter element includes a first filter medium and an outer peripheral wall. The first filter medium is configured to rotate within the housing and to allow axial flow of fluid through it. The outer peripheral wall is positioned radially outward of the first filter medium. A lower end of the outer peripheral wall at least partially defines an outlet point of the rotary filter element through which separated liquid is discharged from the rotary filter element. The stationary filter element includes a second filter medium positioned radially outward from the first filter medium and the outer peripheral wall. The second filter medium is configured to allow fluid to flow radially from the inside out through the second filter medium after passing through the first filter medium. The stationary filter element also includes a lower end cap coupled to a lower portion of the second filter medium, the lower end cap including an inner ridge. The inner ridge at least partially defines an outlet point of the stationary filter element through which separated liquid is discharged from the stationary filter element. The lower end of the outer peripheral wall is positioned axially below the upper edge of the inner ridge, thereby preventing the separated liquid from flowing from the outlet point of the rotary filter element into the stationary filter element.

[0008] It should be understood that all combinations of the foregoing concepts and the additional concepts discussed in more detail below (if these concepts are inconsistent with each other) are contemplated as part of the subject matter disclosed herein. In particular, all combinations of the claimed subject matter appearing at the end of this disclosure are contemplated as part of the subject matter disclosed herein. Brief description of the attached diagram

[0009] The above and other features of this disclosure will become more fully apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings. It should be understood that these drawings depict only a few embodiments according to this disclosure and are therefore not intended to limit its scope; the disclosure will be described with additional specificity and detail using the drawings.

[0010] Figure 1 This is a side cross-sectional view of the crankcase ventilation filter assembly according to an example embodiment.

[0011] Reference to the accompanying drawings is consistent throughout the following detailed description. In the drawings, similar symbols generally identify similar parts unless the context otherwise requires. The illustrative embodiments described in the detailed description, drawings, and claims are not intended to be limiting. Other embodiments may be used, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that aspects of this disclosure, as generally described herein and illustrated in the figures, can be arranged, substituted, combined, and designed in a variety of different configurations, all of which are expressly contemplated and are part of this disclosure. Detailed description

[0012] The embodiments described herein generally relate to a rotary crankcase ventilation filter assembly including an axially flowing filter medium positioned around a hub coupled to a central shaft coupled to a motor. The filter medium and the hub are secured between end caps defining an internal volume within which the filter medium and the hub are contained.

[0013] Various crankcase ventilation filter assemblies are described generally with reference to the accompanying drawings. The described filter assemblies can increase the number of particles filtered from engine-generated fluids (i.e., leaky gases) by providing a two-stage filtration system. The first stage may include a rotary filter element configured to allow axial flow of gas through a first filter medium. The second stage may include a stationary filter element configured to allow radial flow (e.g., from the inside out) of gas through a second filter medium. The stationary filter element may be positioned around the rotary filter element such that gas that has already traveled through the rotary filter element can be filtered again before exiting the filter assembly to remove any remaining particles from the gas.

[0014] Rotary filter elements can remove most particles from blow-by gases from an engine, but the addition of an external fixed filter element allows the filtration system to remove particles that might have been missed by the rotary filter element. This can further reduce pollutants released into the atmosphere in open crankcase ventilation systems or improve engine efficiency in closed crankcase ventilation systems. For example, both rotary and fixed filter elements can capture particles of all sizes, but rotary filter elements are more effective for larger particles, while fixed filter elements are more effective for smaller particles. For instance, fixed filter elements can be more effective than rotary filter elements in capturing particles <0.4 micrometers. Additionally, using fixed filter elements can reduce the complexity and cost that might arise when attempting to achieve ultra-high efficiency using only rotary filter elements.

[0015] refer to Figure 1 The image shows a cross-sectional view of a crankcase ventilation filter assembly 100 according to an example embodiment. The crankcase ventilation filter assembly 100 generally processes blow-by gases received from the crankcase of an internal combustion engine to remove aerosols, oil, and other particulate matter contained within the blow-by gases. The crankcase ventilation filter assembly 100 generally includes a housing 200 having an inlet 202 for receiving the blow-by gases to be filtered, a central compartment 204, and an outlet 206 that supplies the filtered blow-by gases to the internal combustion engine (in a closed crankcase ventilation system) or to the environment (in an open crankcase ventilation system).

[0016] The crankcase ventilation filter assembly 100 includes a drive shaft 208 extending axially relative to the housing 200. The drive shaft 208 may extend at least partially through a central compartment 204 of the housing 200. At least a portion of the central compartment may be a chamber 210. The chamber 210 may be configured to receive and collect oil and aerosols separated from leaking gases. The housing 200 has at least one drain 212 configured to discharge separated liquids from the crankcase ventilation filter assembly 100 back into the engine.

[0017] The crankcase ventilation filter assembly 100 includes a two-stage filtration system comprising a rotary filter element 300 and a fixed filter element 400. The rotary filter element 300 is at least partially located within the housing 200. Figure 1In this embodiment, the rotary filter element 300 is a rotary coalescer element. The rotary filter element 300 can be any type of rotary coalescer. For example, the rotary filter element 300 can be electrically driven, hydraulically driven, mechanically driven, or pneumatically driven. A drive shaft 208 is coupled to the rotary filter element 300 to rotate the rotary filter element 300.

[0018] The rotary filter element 300 includes a first filter medium 302. The first filter medium 302 is configured to allow axial flow of gas through it. For example, the first filter medium 302 may have an axial flow channel arranged in a direction generally parallel to the axis defined by the drive shaft 208 of the crankcase ventilation filter assembly 100. Therefore, the rotary filter element 300 is an axial flow coalescing element. In some arrangements, the first filter medium 302 is a wound filter media. The overall shape of the first filter medium 302 may be a truncated cone, such that the axial flow channel is not arranged in a direction generally parallel to the axis defined by the drive shaft 208 of the crankcase ventilation filter assembly 100.

[0019] like Figure 1 As shown (indicated by flow arrows), crankcase gas flows from inlet 202, enters the first filter medium 302 from its first bottom end, passes through the first filter medium 302 axially, and exits from its second top end. Coalesced liquid (e.g., oil and aerosol separated from crankcase leaks) passes through the layer of the first filter medium 302, and the separated liquid exits into the bottom region of the rotary filter element 300 through an opening shown as the rotary filter outlet point 304, at the maximum local radius from the central axis of the rotary filter element 300 (e.g., the axis defined by drive shaft 208). In some arrangements, the rotary filter element 300 is positioned such that gravity facilitates the discharge of the separated liquid from the housing 200.

[0020] The rotary filter element 300 may include a drain lip 306. The drain lip 306 is defined by a diameter smaller than the diameter of the outer peripheral wall 308 of the rotary filter element 300. The drain lip 306 may abut against and extend inward from the outer peripheral wall 308. Because the first filter medium 302 is held below the drain lip 306, and because the coalesced / separated liquid is radially outwardly biased (e.g., toward the outer peripheral wall 308, etc.) and therefore biased toward the outer peripheral wall 308 below the drain lip 306, the inward and upward extension of the drain lip 306 can mitigate the outflow of coalesced / separated liquid from the first filter medium 302.

[0021] The fixed filter element 400 of the crankcase ventilation filter assembly 100 is at least partially located within the housing 200. The fixed filter element 400 includes a second filter medium 402. The second filter medium 402 can be of various types. For example, the second filter medium 402 can be a pleated, molten polymer, including single or multiple layers of glass, including nanofiber layers, or any combination thereof. The second filter medium 402 is positioned radially outward from the first filter medium 302. The second filter medium 402 extends around the first filter medium 302. The second filter medium 402 can have any shape extending around the first filter medium 302. For example, the second filter medium 402 can be cylindrical or non-cylindrical. The second filter medium 402 is configured to allow gas to flow radially (e.g., from the inside out) through the second filter medium 402. For example, after leaking gas leaves the rotary filter element 300, the leaking gas can flow radially through the second filter medium 402 to remove residual particles from the leaking gas.

[0022] The second filter medium 402 is positioned away from the outer wall of the housing 200, such that an air gap 404 exists between the second filter medium 402 and the housing 200. The air gap 404 allows leaked gas to flow through the second filter medium 402 and exit the crankcase ventilation filter assembly 100 via the outlet 206 of the housing 200. The second filter medium 402 extends across the outlet 206, such that leaked gas leaving the rotary filter element 300 flows through the second filter medium 402 of the stationary filter element 400 before exiting via the outlet 206. The second filter medium 402 may be a coalescing filter medium configured to retain particles from the leaked gas and coalesce the particles into a film, allowing the particles to flow toward the bottom end of the second filter medium 402 for discharge.

[0023] A fixed filter element 400 includes a first end cap 406, shown as an upper end cap, and a second end cap 408, shown as a lower end cap. A second filter medium 402 is coupled to the upper end cap 406 and the lower end cap 408. For example, the second filter medium 402 may be potted (e.g., adhered) or embedded (e.g., fused) into the first end cap 406 and the second end cap 408. The upper end cap 406 may be coupled to the upper end of the second filter medium 402.

[0024] The upper end cap 406 includes a first sealing member 410. The first sealing member 410 can be configured to form a first seal between the upper end cap 406 and the housing 200. Figure 1 In the illustrated embodiment, the first sealing member 410 is positioned within a radially extending recess of the upper end cap 406 and is positioned to form a radially oriented seal with the housing 200.

[0025] The lower end cap 408 includes a second sealing member 412. The second sealing member 412 can be configured to form a second seal between the lower end cap 408 and the housing 200. Figure 1 In the illustrated embodiment, the second sealing member 412 is positioned within a radially extending recess of the lower end cap 408 and is positioned to form a radially oriented seal with the housing 200.

[0026] The resulting seal can be of any type, including but not limited to radial seals, axial seals, or contact seals. The first sealing member 410 and the second sealing member 412 are configured to form a seal with the housing 200 that prevents gas from leaving the stationary filter element at any location other than the designated outlet 206. The first sealing member 410 and the second sealing member 412 can be any type of element configured to form a seal with the housing 200. For example, the first sealing member 410 and the second sealing member 412 can be elastomeric or non-elastomeric.

[0027] The lower end cap 408 includes a base 414. The base 414 is configured to engage and connect to the lower end of the second filter medium 402. The lower end cap 408 includes an inner ridge 416 extending a first distance from the base 414 toward the upper end of the second filter medium 402. The lower end cap 408 includes an outer ridge 418 extending a second distance from the base 414 toward the upper end of the second filter medium 402. In some embodiments, the first distance may be less than the second distance. For example, the base 414, the inner ridge 416, and the outer ridge 418 may define a receptor 420 configured to receive liquid separated from leaked gas via the second filter medium 402. Figure 1 In the embodiment shown, the outer ridge 418 defines a radially oriented recess in the lower end cap, wherein the second sealing member 412 is positioned in the radially oriented recess in the lower end cap.

[0028] The fixed filter element 400 has at least one fixed filter outlet point 422 for allowing separated liquid to exit the containment portion 420 and be discharged into the chamber 210. When the first distance is less than the second distance, the upper edge of the inner ridge 416 is lower than the upper edge of the outer ridge 418, causing the collected liquid to converge in the containment portion 420, eventually flowing through the inner ridge 416 and being discharged from the fixed filter element 400 via the fixed discharge portion 424. Thus, the fixed filter outlet point can be the upper edge of the inner ridge 416. In some embodiments, the first distance can be the same as or greater than the second distance, such that the upper edge of the inner ridge 416 is flush with or higher than the upper edge of the outer ridge 418. In such an arrangement, the inner ridge 416 may include at least one discharge opening located at a third distance from the base 414. The third distance is smaller than the second distance of the outer ridge 418, so that the collected liquid can be discharged from the receiving portion 420 through the discharge opening in the inner ridge 416. Thus, the discharge opening can be a fixed filter outlet point 422.

[0029] In some embodiments, liquid separated from leaked gas in the rotary filter element 300 and liquid separated from leaked gas in the stationary filter element 400 are collected in the same chamber 210. That is, the same chamber 210 is in inseparable liquid receiving communication with both the rotary filter element 300 and the stationary filter element 400, and is discharged from the chamber 210 via the same discharge portion 212. In other embodiments, the housing 200 may include multiple chambers 210 and discharge portions 212. For example, liquid from the rotary filter element 300 may exit the housing 200 via a first chamber 210 and a first discharge portion 212, and liquid from the stationary filter element 400 may exit the housing 200 via a second chamber 210 and a second discharge portion 212.

[0030] The crankcase ventilation filter assembly 100 also includes a barrier 500. The barrier 500 is at least partially positioned between the first filter medium 302 and the second filter medium 402. The barrier 500 is configured to prevent liquid captured by the rotary filter element 300 from entering the stationary filter element 400. For example, the barrier 500 may position the rotary element outlet point 304 below the stationary filter outlet point 422. For example, the barrier 500 may be the bottom end of the outer peripheral wall 308 of the rotary filter element 300. The end of the barrier 500 may be positioned axially below the upper edge of the inner ridge 416 of the lower end cap 408, such that the rotary element outlet point 304 is positioned below the stationary filter outlet point 422, thereby preventing or blocking liquid from flowing from the rotary filter element 300 into the stationary filter element 400.

[0031] It should be noted that the term “example” 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 imply that such embodiments must be particular or best examples).

[0032] As used herein, the terms “link”, “connection”, etc., refer to the direct or indirect connection between two components. Such a connection can be fixed (e.g., permanent) or movable (e.g., removable or releasable). Such a connection can be achieved by the two components, or two components and any additional intermediate components, being integrally formed into a single unit, or by the two components, or two components and any additional intermediate components, being attached to each other.

[0033] It is important to note that the structures and arrangements of the various exemplary embodiments are merely illustrative. While only a few embodiments have been described in detail in this disclosure, those skilled in the art will readily recognize that many modifications (e.g., variations in the size, dimensions, structure, shape and proportion of various elements, values ​​of parameters, mounting arrangements, use of materials, color, orientation, etc.) are possible without substantially departing from the novel teachings and advantages of the subject matter described herein. Other substitutions, modifications, variations, and omissions may also be made in the design, operating conditions, and arrangements of the various exemplary embodiments without departing from the scope of the embodiments described herein.

[0034] While this specification contains numerous specific implementation details, these should not be construed as limiting any embodiment or the scope of the claims, but rather as descriptions of features characteristic of a particular implementation of a particular embodiment. Certain features described in the context of individual implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented individually or in any suitable sub-combination in multiple implementations. Furthermore, although the foregoing features may be described as functioning in certain combinations, or even originally claimed, in some cases one or more features from a claimed combination may be removed from that combination, and the claimed combination may refer to a sub-combination or a variation of a sub-combination.

Claims

1. A crankcase ventilation filter assembly, comprising: case; A rotary filter element, at least partially located within the housing, the rotary filter element including a first filter medium configured to rotate within the housing and constructed to allow axial flow of fluid through the first filter medium; and A fixed filter element, at least partially located within the housing, the fixed filter element including a second filter medium radially outwardly positioned from a first filter medium and configured to allow gas to flow radially outward through the second filter medium; An air gap is defined between the second filter medium and the housing, such that fluid leaving the second filter medium flows through the air gap and out of the crankcase ventilation filter assembly.

2. The crankcase ventilation filter assembly according to claim 1, wherein, The fixed filter element also includes: The upper end cap, connected to the upper end of the second filter medium, includes a first sealing member configured to form a first seal with the housing; and The lower end cap is connected to the lower end of the second filter medium, and the lower end cap includes a second sealing member configured to form a second seal with the housing.

3. The crankcase ventilation filter assembly according to claim 1, wherein, The first seal and the second seal are radially oriented seals.

4. The crankcase ventilation filter assembly according to claim 1, wherein, The fixed filter element also includes: The lower end cap is connected to the lower end of the second filter medium, and the lower end cap includes: - Base, which is engaged with the second filter medium; - An inner ridge extending a first distance from the base toward the upper end of the second filter medium; and - An external ridge extending a second distance from the base toward the upper end of the second filter medium; Wherein, the first distance is less than the second distance.

5. The crankcase ventilation filter assembly according to claim 4, wherein, The outer ridge defines a radially oriented recess in the lower end cover, and the crankcase ventilation filter assembly further includes a sealing member positioned within the radially oriented recess in the lower end cover, the sealing member forming a radially oriented seal with the housing.

6. The crankcase ventilation filter assembly according to claim 4, wherein, The base, the inner ridge, and the outer ridge cooperate to define a receiving portion, the receiving portion being configured to receive separated liquid, and wherein the fixed filter element further includes a fixed discharge portion through which the separated liquid flows out of the receiving portion.

7. The crankcase ventilation filter assembly according to claim 6, wherein, The housing defines a housing receiving portion below at least one of the rotary filter element and the fixed filter element, the housing receiving portion being in communication with the fixed filter element via the fixed discharge portion in a manner to receive separated liquid.

8. The crankcase ventilation filter assembly according to claim 7, wherein, The housing also includes a housing discharge section, which is connected to the housing receiving section in a manner that receives separated liquid.

9. The crankcase ventilation filter assembly according to claim 8, wherein, The rotary filter element defines a rotary filter element outlet point, and wherein the housing housing is in communication with the rotary filter element via the rotary filter element outlet point in a manner to receive separated liquid.

10. The crankcase ventilation filter assembly according to claim 9, wherein, The rotary filter element includes an outer peripheral wall positioned radially outside the first filter medium, and wherein the outlet point of the rotary filter element is defined between the first filter medium and the lower end of the outer peripheral wall.

11. The crankcase ventilation filter assembly of claim 1, further comprising a barrier at least partially positioned between the first filter medium and the second filter medium, the barrier preventing liquid separated by the rotary filter element from entering the stationary filter element.

12. The crankcase ventilation filter assembly according to claim 11, wherein, The fixed filter element also includes: The lower end cap is connected to the second filter medium, and the lower end cap includes an inner ridge, with the end of the barrier positioned below the top edge of the inner ridge.

13. The crankcase ventilation filter assembly according to any one of claims 1-10, wherein: The housing includes an outlet through which filtered fluid exits the crankcase ventilation filter assembly; and The second filter medium extends across the outlet.

14. The crankcase ventilation filter assembly according to claim 1, wherein, The rotary filter element also includes: The outer peripheral wall is located radially outside the first filter medium; and The discharge lip extends radially inward and axially upward from the upper end of the outer peripheral wall. The discharge lip retains the separated liquid below the discharge lip and reduces the outflow of the separated liquid from the first filter medium to the second filter medium.

15. A filter assembly, comprising: case; A rotary filter element, at least partially positioned within the housing, the rotary filter element comprising: - A first filter medium, configured to rotate within the housing and constructed to allow axial flow of fluid through the first filter medium, and - An outer peripheral wall, positioned radially outside the first filter medium, the lower end of the outer peripheral wall at least partially defining the outlet point of the rotary filter element, through which the separated liquid is discharged from the rotary filter element; and A fixed filter element, at least partially positioned within the housing, the fixed filter element comprising: - A second filter medium, positioned radially outward from the first filter medium and the outer peripheral wall, the second filter medium being configured to allow the fluid to flow radially from the inside out through the second filter medium after passing through the first filter medium. - A lower end cap, connected to the lower portion of the second filter medium, the lower end cap including an inner ridge that at least partially defines the outlet point of a fixed filter element, through which separated liquid is discharged from the fixed filter element. The lower end of the outer peripheral wall is positioned axially below the upper edge of the inner ridge, thereby preventing the separated liquid from flowing into the fixed filter element from the outlet point of the rotary filter element.

16. The filter assembly of claim 15, wherein, The housing defines at least one housing housing portion positioned axially below at least one of the rotary filter element and the fixed filter element, each of the at least one housing housing portion communicating with at least one of the rotary filter element and the fixed filter element in a manner that receives separated liquid.

17. The filter assembly of claim 16, wherein, The housing further includes at least one housing discharge section, each of which is in communication with at least one of the at least one housing receiving section in a manner that receives separated liquid.

18. The filter assembly according to any one of claims 15-17, further comprising a discharge lip extending radially inward and axially upward from the upper end of the outer peripheral wall, the discharge lip retaining the separated liquid below the discharge lip and reducing the outflow of the separated liquid from the first filter medium to the second filter medium.

19. The filter assembly according to any one of claims 15-17, wherein, The lower end cap defines a radially oriented recess, and the filter assembly further includes a sealing member positioned within the radially oriented recess of the lower end cap, the sealing member forming a radially oriented seal with the housing.

20. The filter assembly according to any one of claims 15-17, wherein, The lower end cap further includes a base that engages with the second filter medium and an outer ridge extending from the base toward the upper end of the second filter medium, wherein the base, the inner ridge, and the outer ridge cooperate to define a receiving portion configured to receive liquid separated from the second filter medium.

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