Patent Publication Number: US-8979958-B2

Title: Air cleaner pre-filtration improvement

Description:
FIELD 
     The present disclosure relates to air filters and, more particularly, to an air filter incorporating a particle separator. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     Air filters may be used in conjunction with an engine to provide the engine with a constant supply of clean air during use. For example, an air filter may be positioned upstream of an internal combustion engine in a vehicle to supply an intake manifold of the vehicle and, thus, the internal combustion engine, with clean air. The internal combustion engine utilizes the air supplied by the intake manifold and air filter and mixes the air with fuel during combustion. Providing the air filter upstream of the intake manifold and internal combustion engine improves the efficiency of and prevents damage to the engine by reducing the intake of solid particulate such as, for example, dust, dirt, and other debris into combustion chambers of the internal combustion engine. 
     Air filters typically include a filter media disposed within a housing that permits the passage of air therethrough between an inlet and an outlet. The filter media is typically configured to allow air to pass from the inlet to the outlet while concurrently removing solid particulate from the air flow. Once cleaned, the air is drawn from the housing and into the intake manifold for use by the engine during combustion while the solid particulate remains in the filter media and/or housing of the air filter. 
     Under normal operating conditions, a conventional air filter adequately removes solid particulate from incoming air prior to expelling cleansed air to the intake manifold and internal combustion engine. However, over time and/or when operating in dusty, sandy, or otherwise debris-laden environments, the filter media may become clogged with solid particulate, thereby reducing the effectiveness of the filter media in removing solid particulate from an air flow. Further, when the filter media becomes laden with solid particulate, air flow through the filter is reduced. As a result, the volume of clean air provided to the engine is insufficient, thereby reducing the efficiency of the engine. Only when the air filter is permitted to concurrently remove solid particulate from air entering the air filter and provide the engine with a sufficient volume of clean air does the engine operate efficiently. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     An air filter is provided and may include a first housing and a filter media disposed within the first housing. A second housing may include an inlet port receiving air at a first pressure from the first housing and an outlet port returning the air to the first housing at a second pressure, less than the first pressure. The second housing may remove debris from the air prior to returning the air to the first housing. 
     In another configuration, an air filter is provided and may include a first housing having a first inlet, a second inlet, a first outlet, and a second outlet. A filter media may be disposed within the first housing and may cleanse air received by the first housing at the first inlet prior to the air being expelled from the housing at the first outlet. A second housing may be fluidly coupled to the first housing at the second outlet and may be fluidly coupled to the first housing at the second inlet. The second housing may cleanse the air received at the first inlet prior to the air passing through the filter media. The air may be drawn through the second housing due to a difference in static pressure between the second outlet and the second inlet. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG. 1  is an environmental view of an air filter for use in conjunction with an intake manifold and engine; 
         FIG. 2  is a cross-sectional view of the air filter of  FIG. 1  taken along line  2 - 2  of  FIG. 1 ; 
         FIG. 3  is a cross-sectional view of a portion of the air filter of  FIG. 1  taken along line  3 - 3  of  FIG. 1 ; 
         FIG. 4  is a cross-sectional view of a portion of the air filter of  FIG. 1  taken along line  4 - 4  of  FIG. 3 ; 
         FIG. 5  is a partial cross-sectional view of a discharge valve of the air filter of  FIG. 1  shown in a closed state; and 
         FIG. 6  is a partial cross-sectional lateral view of a discharge valve of the air filter of  FIG. 1  (rotated 90 degrees relative to  FIG. 5 ), shown in an open state. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
     When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
     Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     With reference to the figures, an air filter  10  is provided and may include a main-filter assembly  12  and a particle separator  14 . The particle separator  14  is fluidly coupled to the main-filter assembly  12  and cooperates with the main-filter assembly  12  to remove solid particles from air received by the main-filter assembly  12 . 
     The main-filter assembly  12  may include a housing  16  and a filter media  18 . The housing  16  may include an air inlet  20  and a clean-air outlet  22 . The air inlet  20  may be formed tangentially to an inner surface  24  ( FIG. 2 ) of the housing  16  to induce a swirl to air entering the housing  16  at the air inlet  20 . The clean-air outlet  22  may be formed at an end  26  of the housing  16  that is substantially perpendicular to the air inlet  20 . 
     In one configuration, the clean-air outlet  22  is fluidly coupled to an engine  28  via an intake manifold  30 . As will be described in greater detail below, fluidly coupling the clean-air outlet  22  to the engine  28 —via the intake manifold  30 —allows the air filter  10  to provide a supply of clean air to the engine  28  for use by the engine  28  during combustion. 
     The housing  16  may additionally include a separator outlet  32  and a separator inlet  34  that are fluidly coupled to the particle separator  14 . Specifically, the separator outlet  32  is fluidly coupled to the particle separator  14  to supply the particle separator  14  with air while the separator inlet  34  is fluidly coupled to the particle separator  14  to receive cleansed air from the particle separator  14 . 
     The filter media  18  may be centrally located within the housing  16  and may include an outer surface  36  and an inner surface  38  separated by a corrugated or pleated filter element  40 . The outer surface  36  may cooperate with the inner surface  38  to provide the filter media  18  with a substantially cylindrical shape. The filter element  40  is disposed generally between the outer surface  36  and the inner surface  38  of the filter media  18  and may be formed from any suitable material that adequately separates solid particulate from air received at the air inlet  20  of the housing  16  while concurrently allowing air to pass through the filter element  40 . 
     Once the filter media  18  is disposed within the housing  16 , the filter media  18  defines a so-called “dirty” zone  42  and a so-called “clean” zone  44 . The dirty zone  42  is in fluid communication with the air inlet  20  and receives ambient air from an area generally surrounding the air filter  10 . The air received at the air inlet  20  is referred to as “dirty,” as the ambient air likely contains solid particulate  45  ( FIGS. 5 and 6 ) such as, for example, dust, dirt, and other debris. The area identified by reference number  44  is referred to as the “clean” zone, as air received at the air inlet  20  of the housing  16  first passes through the filter media  18  prior to entering the clean zone  44  and, therefore, is substantially free from solid particulate  45 . In short, the air disposed within the dirty zone  42  may be laden with solid particulate  45  while the air disposed within the clean zone  44  is clean. 
     With particular reference to  FIGS. 3-6 , the particle separator  14  is shown as including a housing  46  and a discharge valve  48 . The housing  46  may include a substantially cylindrical shape and, further, may include an inlet  50  and an outlet  52 . The housing  46  may additionally include a baffle  54 , as well as a cone-shaped extension  56 . 
     The inlet  50  may be positioned relative to the housing  46  such that the inlet  50  is substantially tangential to an inner surface  58  of the housing  46 . As such, air received at the inlet  50  engages the inner surface  58  of the housing  46 , thereby causing the incoming air to swirl within the housing  46 . The baffle  54  may be positioned relative to the inner surface  58  such that a gap  60  is provided between an outer surface  62  of the baffle  54  and the inner surface  58  of the housing  46 . In one configuration, the baffle  54  includes a substantially circular shape that mimics the substantially circular cross-section of the housing  46  such that the outer surface  62  of the baffle  54  is substantially evenly spaced from the inner surface  58  of the housing  46 . The baffle  54  may cooperate with the inner surface  58  to provide a first path  64  defined generally by the gap  60  that receives and directs air within the housing  46  when air is introduced into the housing  46  at the inlet  50 . 
     While the baffle  54  is described as including a substantially circular shape and, further, as including a shape that substantially mimics the cylindrical shape of the housing  46 , the baffle  54  may include a first end  66  and a second end  68 , whereby the first end  66  is separated from the second end  68  to define an opening  70  extending through the baffle  54 . In one configuration, the first end  66  is spaced apart and separated from the second end  68  to define a width of the opening  70  and, further, overlaps the second end  68  when viewed in cross-section ( FIG. 4 ). 
     The cone-shaped extension  56  may include a surface  72  that is formed at an angle (β) relative to a longitudinal axis  74  of the housing  46 . The surface  72  may extend from the inner surface  58  of the housing  46  to an opening  76  located at a distal end of the cone-shaped extension  56 . The opening  76  may be aligned with the outlet  52  of the housing  46  such that the longitudinal axis  74  passes through the centers of the outlet  52  and the opening  76 . Additionally, because the surface  72  is formed at an angle (β) relative to the longitudinal axis  74  of the housing  46 , a pocket  78  may be formed between an inner surface  80  of the housing  46  located proximate to the discharge valve  48  and an outer surface  82  of the cone-shaped extension  56 . 
     With particular reference to  FIGS. 5 and 6 , the discharge valve  48  is shown to include a normally open valve member  84  movable between a closed state ( FIG. 5 ) and an open state ( FIG. 6 ). The valve member  84  may include a channel  86  shaped to receive a distal end  88  ( FIG. 3 ) of the housing  46 . In one configuration, the distal end  88  may include a localized thick spot or flange that is matingly received by the channel  86  of the valve member  84  to retain the valve member  84  in a desired position relative to the housing  46 . Further, the channel  86  may be sized such that the valve member  84  must be slightly expanded in order to accommodate the distal end  88  of the housing  46  to increase the frictional engagement between the valve member  84  and the housing  46 . The valve member  84  may be formed from an elastomeric material such as, for example, rubber. As such, the material of the valve member  84  may enhance the frictional engagement between the channel  86  of the valve member  84  and the distal end  88  of the housing  46  to further retain the valve member  84  on the housing  46 . 
     The valve member  84  may include a distal end  90  having a pair of opposing walls  92  that are moved away from one another when the valve member  84  is in the open state to permit the passage of debris through the distal end  90  and between the walls  92 . The walls  92  are shown in  FIG. 5  as being in contact with one another and are shown as being partially separated from one another in  FIG. 6 , whereby the view shown in  FIG. 6  is rotated approximately ninety degrees (90°) relative to the view shown in  FIG. 5 . 
     The walls  92  may be brought toward one another until at least a portion of the opposing walls  92  are in contact with one another to move the valve member  84  from the open state ( FIG. 6 ) to the closed state ( FIG. 5 ). In other words, the walls  92  may be moved toward one another until inner surfaces  94  ( FIG. 6 ) of each wall  92  are in contact with one another. Once the inner surfaces  94  of the respective walls  92  are in contact with one another, the discharge valve  48  is in the closed state ( FIG. 5 ) and passage through the distal end  90  of the valve member  84  is restricted. 
     The discharge valve  48  may be a normally open, fluidly actuated valve that responds to pressure changes within the housing  46 . Therefore, when the housing  46  is at atmospheric pressure, the elastomeric material of the valve member  84  may cause the discharge valve  48  to be moved into the open state ( FIG. 6 ) such that the walls  92  are moved away from one another and the inner surfaces  94  of the respective walls  92  are separated. Conversely, when the housing  46  is subjected to vacuum pressure, a force may be applied to the valve member  84 , thereby causing the walls  92  to move toward one another until the discharge valve  48  is moved into the closed state ( FIG. 5 ) and the inner surfaces  94  of the respective walls  92  are once again in contact with one another. In this position, solid particulate  45  may collect within the valve member  84  and is restricted from exiting the housing  46  at the distal end  90 . However, when the vacuum applied to the housing  46  is released, the normally open valve member  84  is returned to the open state ( FIG. 6 ), thereby allowing the solid particulate  45  disposed within the valve member  84  and housing  46  to be expelled from the discharge valve  48  and housing  46  via the distal end  90  of the valve member  84 . 
     With particular reference to  FIGS. 3-6 , operation of the air filter  10  will be described in detail. When the engine  28  is operating, a vacuum force is applied to the air filter  10 . Specifically, the engine  28  imparts a vacuum on the housing  16 , thereby causing ambient air to be drawn into the housing  16  at the air inlet  20 . The incoming air is received within the dirty zone  42  of the housing  16  and swirls generally within the housing  16 . The air engages the filter media  18 , which causes a portion of the air to pass through the filter media  18  from the dirty zone  42  to the clean zone  44 . In so doing, solid particulate  45  disposed within the ambient air located within the dirty zone  42  is deposited into or on the filter media  18  prior to the air passing through the filter media  18  and reaching the clean zone  44 . The air disposed within the clean zone  44  is likewise subjected to vacuum pressure caused by operation of the engine  28  and is expelled from the housing  16  via the clean-air outlet  22 . The clean air exits the housing  16  at the clean-air outlet  22  and passes to the engine  28  via the intake manifold  30 . 
     While a portion of the air drawn into the housing  16  at the air inlet  20  passes through the filter media  18  and moves from the dirty zone  42  to the clean zone  44 , a portion of the incoming air at the air inlet  20  may first exit the housing  16  at the separator outlet  32 . The air exiting the housing  16  at the separator outlet  32  may be laden with solid particulate  45  due to the ambient air entering the housing  16  at the air inlet  20  being laden with solid particulate  45 . Additionally, because the filter media  18  separates solid particulate  45  from air passing through the filter media  18 , solid particulate  45  trapped by the filter media  18  may be released by the filter media  18  and may ultimately collect proximate to a bottom portion of the housing  16  and near the separator outlet  32 . Therefore, as air passes through the separator outlet  32 , the air may collect the solid particulate  45  located within the bottom portion of the housing  16  and proximate to the separator outlet  32  and may carry the solid particulate  45  out of the housing  16  at the separator outlet  32 . 
     A portion of the air disposed within the dirty zone  42  may be drawn into the separator outlet  32  due to the vacuum pressure exerted on the housing  16  at the clean-air outlet  22 . Specifically, the separator outlet  32  may be at a higher pressure than the separator inlet  34  and, as a result, the air located within the dirty zone  42  may be drawn out of the housing  16  at the separator outlet  32 , thereby causing the air to pass through the particle separator  14 . In other words, the differential static pressure within the housing  16  causes air to be drawn out of the housing  16  at the separator outlet  32  such that the air is drawn through the particle separator  14  and ultimately is returned to the housing  16  at the separator inlet  34 . This phenomenon is further enhanced by air swirling within the housing  16  passing over the separator inlet  34 . Specifically, when the swirling air passes over the separator inlet  34 , the air imparts a vacuum on the separator inlet  34 , which further contributes to the pressure difference between the separator outlet  32  and the separator inlet  34 . 
     The particulate-laden air drawn from the housing  16  flows through the particle separator  14  to allow the particle separator  14  to remove the particulate from the air prior to returning cleansed air to the housing  16  via the separator inlet  34 . Removing the particulate from the housing  16  extends the lifespan of the filter media  18  by removing the particulate from the housing  16  before the particulate can occlude the filter media  18  and restrict flow therethrough. 
     The particulate-laden air drawn from the housing  16  at the separator outlet  32  may be communicated to the inlet  50  of the particle separator  14  via a conduit  98  ( FIG. 1 ) that fluidly couples the separator outlet  32  of the housing  16  to the inlet  50  of the particle separator  14 . The particle-laden air stream may be received by the housing  46  of the particle separator  14  at the inlet  50  and may be caused to swirl within the housing  46  due to the inlet  50  being positioned substantially tangent to the inner surface  58  of the housing  46 . 
     The incoming air is caused to swirl generally within the first path  64  of the housing  46  due to the swirling motion imparted on the air when the air is first introduced into the housing  46  at the inlet  50 . Because the incoming air is caused to swirl within the first path  64  and substantially around the longitudinal axis  74  of the housing  46 , the heavier, solid particulate  45  located within the air stream is caused to move toward the inner surface  58  of the housing and generally away from the baffle  54 . Once sufficient solid particulate  45  is disposed proximate to the inner surface  58  of the housing  46 , the solid particulate  45  may pass from the first path  64  via an opening  100  and may be received by the surface  72  of the cone-shaped extension  56 . 
     The solid particulate  45  received by the surface  72  of the cone-shaped extension  56  may travel along the surface  72  until the solid particulate  45  encounters the opening  76  of the cone-shaped extension  56 . At this point, the solid particulate  45  passes through the opening  76  and encounters the discharge valve  48 . If the discharge valve  48  is in the closed state ( FIG. 5 ), the solid particulate  45  collects generally within the valve member  84  of the discharge valve  48 . Alternatively, if the discharge valve  48  is in the open state ( FIG. 6 ), the solid particulate  45  passes through the valve member  84  at the distal end  90  and is released to the atmosphere. 
     The discharge valve  48  will be in the closed state ( FIG. 5 ) when the housing  46  is subjected to vacuum pressure caused by operation of the engine  28 . Therefore, when the engine  28  is operating, the housing  46  of the particle separator  14  will be under vacuum pressure and the discharge valve  48  will be in the closed state. Alternatively, when the engine  28  ceases operation, the vacuum pressure imparted on the housing  46  of the particle separator  14  will be released, thereby allowing the valve member  84  to return to the open state to release the solid particulate  45  disposed within the discharge valve  48 . 
     As the air entering the housing  46  swirls within the first path  64  and deposits solid particulate  45  on the surface  72  of the cone-shaped extension  56 , the air may exit the first path  64  via the opening  100  and likewise may engage the cone-shaped extension  56 . The cone-shaped extension  56  may cause the air to additionally swirl within the housing  46  due to the surface  72  of the cone-shaped extension  56  being formed at an angle (β) relative to the longitudinal axis  74  of the housing  46 . The air swirling within the housing  46  may exit the housing via a second path  102  in a direction (Q). Specifically, the air swirling within the cone-shaped extension  56  of the housing  46  is under vacuum pressure due to operation of the engine  28 . Therefore, the engine  28  may draw the air swirling within the cone-shaped extension  56  in the direction (Q) from the housing  46  via the outlet  52 . The air may pass by the baffle  54  and may travel substantially along the longitudinal axis  74  in the direction (Q) until ultimately exiting the housing  46 . 
     The air exiting the housing  46  at the outlet  52  may be received by a conduit  104  ( FIG. 1 ), which may transport the clean air back to the housing  16  of the main-filter assembly  12 . The air may be received by the housing  16  of the main-filter assembly  12  at the separator inlet  34  and may be received within the dirty zone  42 . The air received within the dirty zone  42  will ultimately pass through the filter media  18  and reach the clean zone  44  prior to being drawn into the engine  28  via the clean-air outlet  22  and intake manifold  30 . 
     As described, the air exiting the particle separator  14  at the outlet  52  is substantially free from solid particulate  45 , as the solid particulate  45  has been removed due to the swirling motion imparted on the air entering the housing  46  by the tangential inlet  50  and the first path  64 . However, should solid particulate  45  be disposed within the air swirling within the cone-shaped extension  56  of the housing  46 , the solid particulate  45  will be drawn back into the first path  64  via the opening  70  of the baffle  54 . Specifically, the second end  68  of the baffle  54  may extend into the second path  102  and may be positioned to receive air swirling in the direction (W;  FIG. 4 ). Because the solid particulate  45  is heavier than the air and, further, because the air is swirling in the direction (W) within the cone-shaped extension  56 , the solid particulate  45  will be forced against an inner surface  106  of the baffle  54 . The solid particulate  45  collecting against the inner surface  106  of the baffle  54  may be directed through the opening  70  of the baffle  54  and, ultimately, may be received within the first path  64 . 
     The solid particulate  45  re-entering the first path  64  via the opening  70  may mix with incoming air at the inlet  50 , which will cause the solid particulate  45  to mix with solid particulate  45  entering the housing  46  at the inlet  50 . As described, solid particulate  45  entering the housing  46  at the inlet  50  engages the inner surface  58  of the housing  46  and is ultimately expelled from the housing  46  via the opening  100  and discharge valve  48 . Therefore, as air swirling within the cone-shaped extension  56  in the direction (W) exits the housing  46  along the second path  102  and in the direction (Q), any solid particulate  45  located within the air engages the inner surface  106  of the baffle  54  and is ultimately directed through the opening  70  by the second end  68  of the baffle  54  as the air flow exits the housing  46  along the second path  102 . In short, the particle separator  14  removes most of the solid particulate  45  disposed within the air received at the inlet  50  and, further, removes any remaining solid particulate  45  disposed within the air as the air exits the particle separator  14  along the second path  102  due to the first path  64  being in communication with the second path  102 . 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.