Patent Publication Number: US-2011061635-A1

Title: Crankcase Ventilation Device for Internal Combustion Engines

Description:
FIELD OF THE INVENTION 
     The present invention relates to internal combustion engines and, more particularly, to a device for filtering ventilation gas emission from the crankcase of a diesel engine. 
     BACKGROUND OF THE INVENTION 
     Modern internal combustion engines, such as diesel engines, are configured to provide an exhaust pathway to relieve the buildup of fumes in the crankcase.  FIG. 1  is a diagrammatical side view of an engine  10  and radiator  11 . A crankcase ventilation tube  13  is shown attached to a ventilation port (not shown) on a crankshaft cover  17  of the engine  10 , where the crankcase ventilation tube  13  typically has an open end directed generally at the ground. 
     Because some of the crankcase oil provided in an oil pan  15  is mixed in with the crankcase fumes, engine oil is also vented to the atmosphere along with the exhaust gas In the process of emitting the crankcase fumes via the crankcase ventilation tube  13 . As the engine  10  continues to operate, some of this crankcase oil accumulates on the surfaces of the engine  10 , and some is dispersed into the atmosphere or is deposited on the ground. 
     What is needed is a device and method for reducing the amount of crankcase oil emitted to the atmosphere while still providing adequate ventilation for the crankcase of an internal combustion engine. 
     BRIEF SUMMARY OF THE INVENTION 
     In one aspect of the present invention, a conduit filter for an internal combustion engine comprises: a tubular conduit configured to enclose a stream of crankcase ventilation from the engine; and one or more vanes attached to an interior conduit surface of the tubular conduit, the one or more vanes protruding into the stream of crankcase ventilation to stimulate turbulence in the stream of crankcase ventilation so as to facilitate the deposition of oil from the stream of crankcase ventilation onto the interior conduit surface and onto surfaces of the one or more vanes. 
     In another aspect of the present invention, a conduit filter device suitable for use at a crankcase ventilation port on an internal combustion engine comprises: an elbow configured for attachment to the crankcase ventilation port; a conduit filter attachable to the elbow such that a longitudinal axis of the conduit filter is maintained in a substantially vertical orientation when the conduit filter is attached to the elbow, the elbow being attached to the crankcase ventilation port; and a transitional conduit attachable to the conduit filter, the transitional conduit including a first transitional portion and a second transitional portion, the second transitional portion having a longitudinal axis oriented at an angle to a longitudinal axis of the first transitional portion, the first transitional portion longitudinal axis oriented at an angle to the conduit filter longitudinal axis when the transitional conduit is attached to the conduit filter. 
     In yet another aspect of the present invention, a method for filtering oil from the crankcase cover ventilation exhaust of an internal combustion engine comprises: removing, from a ventilation port on the crankcase cover, a crankcase ventilation component provided with the engine; attaching an input end of a conduit filter device to the ventilation port, the conduit filter device configured to stimulate turbulence in ventilation exhaust passing through the conduit filter device, the turbulence functioning to facilitate the deposition of oil droplets from the ventilation exhaust onto an interior surface of the conduit filter device; and attaching at least a portion of the crankcase ventilation component to an output end of the conduit filter assembly. 
     The additional features and advantage of the disclosed invention is set forth in the detailed description which follows, and will be apparent to those skilled in the art from the description or recognized by practicing the invention as described, together with the claims and appended drawings. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         FIG. 1  is a diagrammatical illustration of a side view of a typical internal combustion engine showing a conventional crankcase ventilation tube, in accordance with the prior art; 
         FIG. 2  is a diagrammatical illustration showing a crankcase ventilation device emplaced on the side of an engine, in accordance with an aspect of the present invention; 
         FIG. 3  is a detail diagrammatical view of the crankcase ventilation device of  FIG. 2  showing a conduit filter attached to the crankshaft cover of the engine with mounting components; 
         FIG. 4  is a detail diagrammatical side view of the conduit filter of  FIG. 3 ; 
         FIG. 5  is a diagrammatical cross sectional view of the conduit filter of  FIG. 3  showing two sets of vanes angled against the direction of air flow to increase turbulence in the ventilation gas emitted from the engine; 
         FIG. 6  is a diagrammatical isometrical view of the conduit filter of  FIG. 5  in an opened configuration to show interior placement of the angled vanes; 
         FIG. 7  is a diagrammatical cross sectional view of an alternate embodiment of a conduit filter, in accordance with the present invention, comprising one set of vanes angled against the direction of air flow and another set of vanes angled toward the direction of air flow; 
         FIG. 8  is a diagrammatical cross sectional view of still another alternate embodiment of a conduit filter, in accordance with the present invention, comprising shorter vanes than the vanes of  FIG. 5 ; 
         FIG. 9  is a diagrammatical cross sectional view of yet another embodiment of a conduit filter, in accordance with the present invention, comprising only one set of vanes; 
         FIG. 10  is a diagrammatical cross sectional view of another embodiment of a conduit filter, in accordance with the present invention, comprising two sets of curved vanes; 
         FIG. 11  is a diagrammatical cross sectional view of another embodiment of a conduit filter, in accordance with the present invention, comprising two sets of vanes having arcuate gaps at the interior surface of the conduit filter; and, 
         FIG. 12  is a diagrammatical cross sectional view of an alternate embodiment of a conduit filter, in accordance with the present invention, comprising two sets of vanes having through holes in the vanes. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
     There is shown in  FIG. 2  an exemplary embodiment of a conduit filter device  30  having a first end  31  attached to a crankshaft cover  21  of an internal combustion engine, such as a diesel engine  20 , in accordance with the present invention. A modified crankcase ventilation component  23  may be attached to a second end  33  of the conduit filter device  30 . The modified crankcase ventilation component  23  may be fabricated from a crankcase ventilation component (not shown) originally provided for or supplied with the diesel engine  20  and previously attached to the crankshaft cover  21  before the conduit filter device  30  was installed. In an exemplary embodiment, a suitable section of the (unmodified) crankcase ventilation component configured for attachment to the crankcase cover ventilation port is removed, and the remaining portion of the crankcase ventilation component may be used as the modified crankcase ventilation component  23 . 
     In the example shown, the original crankcase ventilation component has been reworked to form the modified crankcase ventilation component  23  by removing the original, angled tubular end that mated with the ventilation port. After removal of the angled tubular end, a straight section  25  is available for attachment to the second end  33  of the conduit filter device  30 . In an alternative exemplary embodiment, any suitable tubular component may be attached to the second end  33  of the conduit filter device  30  such that crankcase ventilation exhaust passing through the conduit filter device  30  is directed generally downward as shown. 
     With reference to the detail diagrammatical view of  FIG. 3  and the diagrammatical partial side view of  FIG. 4 , the conduit filter device  30  comprises a conduit filter  50  attached to a ventilation port  27  on the crankshaft cover  21  by means of an elbow  47 . The conduit filter  50  is configured to enclose the stream of crankcase ventilation from the diesel engine  20 , and may have approximately the same diameter as the crankcase ventilation component originally provided with the diesel engine  20 . The elbow  47  may be formed from a metal compound, or from an oil-resistant, heat-resistant elastomeric material, such as plastic or the synthetic rubber commonly found in radiator hoses, for example. 
     The elbow  47  may be secured to the conduit filter  50  and to the ventilation port  27  by means of hose clamps (not shown, for clarity of illustration), or by using other mechanical fastening methods known in the art, including but not limited to, welding, brazing, bonding, and swaging. In an exemplary embodiment, the elastomeric material can withstand temperatures of at least 150° F. The elbow  47  provides an approximately 90° bend and, as such, functions to place the conduit filter  50  in a non-horizontal position, such as in the substantially vertical orientation shown. Accordingly, the stream of crankcase ventilation is redirected to a vertical flow direction in the conduit filter  50 , as indicated by arrow  35 , after passing through the elbow  47 . 
     The conduit filter device  30  further comprises a transitional conduit assembly  40  attached to the conduit filter  50  and to the modified crankcase ventilation component  23 , generally as shown. The attachments at either or both ends of the conduit filter  50  may be made with hose clamps (not shown, for clarity of illustration), or may be mechanically attached as described above for the elbow  47 . The transitional conduit assembly  40  functions to further change the direction of the fluid stream of crankcase ventilation, from the substantially vertical direction in the conduit filter  50  to a generally downward direction in the modified crankcase ventilation component  23 , for expulsion of filtered gas towards the ground. 
     In the configuration shown, the transitional conduit assembly  40  may comprise a first transitional segment  41  configured to redirect the crankcase ventilation exhaust from a substantially upwardly vertical direction to a substantially horizontal direction, and a second transitional segment  43  configured to redirect the crankcase ventilation exhaust from the substantially horizontal direction to a substantially downwardly vertical direction, indicated by arrow  37 . The transitional conduit assembly  40  may comprise a three-piece assembly with a transitional connector  45  for attaching the first transitional segment  41  to the second transitional segment  43 . 
     In an exemplary embodiment, the first transitional segment  41  and the second transitional segment  43  may be formed from metal, and the transitional connector  45  may be formed from an elastomeric material. Attachment of the first transitional segment  41  and the second transitional segment  43  to the transitional connector  45  may be accomplished by adhesion, or by clamping with hose clamps (not shown), as is known in the relevant art. The transitional conduit assembly  40  may be attached to the conduit filter  50  by a connecting sleeve  49  formed from an elastomeric material. Alternatively, the transitional conduit assembly  40  may be formed as or fabricated into a single integral unit or unitary component (not shown), comprising metal and/or elastomeric material, for example, to facilitate assembly to the conduit filter  50  and to the modified crankcase ventilation component  23 , and to lower manufacturing costs. 
     Generally, the internal configuration of the conduit filter  50  is specified to stimulate turbulence in the crankcase ventilation exhaust passing to the atmosphere without impeding the flow of the exhaust. As seen in the cross-sectional view of  FIG. 5 , and in the isometric diagram of  FIG. 6 , a first exemplary embodiment of the conduit filter  50  comprises a plurality of internal vanes  51  attached to an interior surface  53  of a tubular conduit  55  such that the specified turbulence is created in the stream of crankcase ventilation passing upward through the conduit filter  50 , as indicated by arrow  57 . In an exemplary embodiment, the tubular conduit  55  may be approximately six to twenty centimeters in length and approximately two to five centimeters in diameter. It can be appreciated by one skilled in the art that these dimensions can be varied to accommodate the physical dimensions of a particular internal combustion engine and ventilation port specified for emplacement of the conduit filter device  30 . 
     Although eight vanes  51  are shown in the illustration, it should be understood that more or fewer vanes  51  may be used in a particular application, depending upon the rate of the air flow conveyed by the conduit filter  50  and the amount of turbulence to be introduced into the stream of crankcase ventilation. Alternatively, the sizes of the vanes may vary from one end of the conduit filter  50  to the other. The vanes  51  may be formed of metal or plastic, and may be arranged in essentially any pattern that creates or stimulates turbulence in the stream of crankcase ventilation so as to facilitate the deposition of oil droplets from the crankcase ventilation exhaust onto the interior conduit surface  53  and onto the surfaces of the vanes  51 . 
     In an exemplary embodiment, the tubular conduit  55  may be fabricated from a first conduit section  55   a  and a second conduit section  55   b  to aid in the attachment of the vanes  51  to the interior surface  53  during fabrication. The first conduit section  55   a  and the second conduit section  55   b  may match along an interface that is approximately parallel to a longitudinal axis  59  of the tubular conduit  55 . The first conduit section  55   a  and the second conduit section  55   b  may thus comprise approximately equal sectional halves (as shown) of the tubular conduit  55 , or may alternatively be configured as unequal sections (not shown). 
     In the particular embodiment shown, the vanes  51  are angled into the direction of flow of the stream of crankcase ventilation, and extend up to or past the longitudinal axis  59  such that an overlap of vanes  51  is provided, as “seen” by the air flow inside the conduit filter  50 . As the deposited oil droplets collect on the interior conduit surface  53  and on the surfaces of the vanes  51 , aggregations of oil droplets merge to form oil drops which migrate downward toward the elbow  47  due to the force of gravity. The oil drops subsequently flow through the elbow  47 , in response to the force of gravity, and return into the crankcase of the diesel engine  20  rather than being expelled into the atmosphere. The consumption of engine oil in the diesel engine  20  is thereby reduced. It has been observed that, by using a conduit filter device  30  in accordance with the present invention, the reduction in oil consumption may be on the order of one gallon of oil saved for every 1000 miles of diesel engine operation. 
     In another exemplary embodiment, shown in  FIG. 7 , a conduit filter  60  comprises a first plurality of vanes  61  angled against the direction of air flow, indicated by arrow  65 , and a second plurality of vanes  63  angled toward the direction of air flow. In still another exemplary embodiment, shown in  FIG. 8 , a conduit filter  70  comprises a plurality of vanes  71  angled against the direction of air flow, where the vanes  71  do not extend past a longitudinal axis  73  of the conduit filter  70  and are thus shorter than the vanes  51  in  FIG. 5 , above. Accordingly, there may be essentially no overlap of vanes  71  as “seen” by the air flow inside the conduit filter  70 . 
     In still another exemplary embodiment, shown in  FIG. 9 , a conduit filter  80  comprises a plurality of vanes  81  on only one side of the interior surface  83  of the conduit filter  80 . The plurality of vanes  81  may be angled against the direction of air flow, generally as shown, or may be angled in the direction of flow (not shown). In another exemplary embodiment, shown in  FIG. 10 , a conduit filter  80  comprises a plurality of curved vanes  91  and curved vanes  93  (i.e., wherein each vane may be formed with a cylindrical surface, a convex surface, or a concave surface, for example) on an interior surface  95  of a tubular conduit  97 . The vane curvature may be downward, against the direction of air flow, as shown, or upward, toward the direction of air flow (not shown). The orientations of the curved vanes  91  and  93  are here shown as angled against the direction of air flow, indicated by arrow  99 . 
     As seen in the isometric diagram of  FIG. 11  (partially exploded for clarity of illustration), an alternative exemplary embodiment of a conduit filter  100  may comprise a plurality of modified vanes  101 , shown here attached to a first conduit section  105   a  of a tubular conduit  105 , or a plurality of modified vanes  103 , shown here attached to a second conduit section  105   b  of the tubular conduit  105 . It should be understood that, although both the modified vanes  101  and the modified vanes  103  are shown in the tubular conduit  105  for purpose of illustration, the conduit filter  100  will typically comprise only one style of the two modified vane configurations shown. 
     The modified vanes  101  and  103  are configured to provide corresponding arcuate gaps  107  and  109  between the respective modified vanes  101  and  103  and the interior surfaces  115   a  and  115   b  of the first conduit section  105   a  and the second conduit section  105   b . The modified vanes  101  may include a curved edge  111  to form the arcuate gap  107 , and the modified vanes  103  may include a flat edge  113  to form the arcuate gap  109 . The arcuate gaps  107  and  109  are configured to provide bypass air passageways to create further turbulence in the stream of crankcase ventilation. 
     In still another exemplary embodiment, shown in the isometric diagram of  FIG. 12  (partially exploded for clarity of illustration), a conduit filter  120  may comprise a plurality of vented vanes  121 , here shown attached to a first section  125   a  of a tubular conduit  125 , or plurality of vented vanes  123 , here shown attached to a second section  125   b  of the tubular conduit  125 . It should be understood that, although both the vented vanes  121  and the vented vanes  123  are shown in the tubular conduit  125  for purpose of illustration, the conduit filter  120  will typically comprise only one of the two vented vane configurations shown. The vented vanes  121  include through holes  127  spaced randomly in the respective vented vanes  121 , whereas the vented vanes  123  include through holes  129  spaced at regular intervals to provide bypass air passageways. The number of through holes is shown as three or four, for convenience of illustration, but a greater or lesser number of holes can be specified for the vented vanes  121  and  123 , depending on application. 
     Accordingly, the through holes  129  may “line up” from one vented vane  123  to another vented vane  123 . In comparison, the through holes  127  may not “line up” from one vented vane  121  to another vented vane  121 . It can be appreciated by one skilled in the art that the physical characteristics of the air flow turbulence in the conduit filter  120  may differ from the characteristics of the air flow turbulence in the conduit filter  100 . Thus, the configuration of the conduit filter  120  may be more suitable for a particular application than the configuration of the conduit filter  100   
     It should be understood that, while the conduit filters  50 ,  100 , and  120  comprise vanes having the “angled against the direction of air flow” orientation and the “overlapping” configuration as shown in the cross sectional diagrammatical view of  FIG. 5 , a conduit filter configured and fabricated in accordance with the present invention will also include configurations of the conduit filters  50 ,  100 , and  120  comprising vanes having alternative cross sectional orientations and configurations as shown in  FIGS. 7 through 10 . 
     It is also to be understood that the description herein is exemplary of the invention only and is intended to provide an overview for the understanding of the nature and character of the invention as it is defined by the claims. The accompanying drawings are included to provide a further understanding of various features and embodiments of the method and apparatus of the invention which, together with their description serve to explain the principles and operation of the invention. Thus, while the invention has been described with reference to particular embodiments, it will be understood that the present invention is by no means limited to the particular constructions and methods herein disclosed and/or shown in the drawings, but also comprises any modifications or equivalents within the scope of the claims.