Abstract:
The present disclosure generally relates to a locomotive diesel engine and, more particularly, to a heavy particle oil separator splash shield. Specifically, provided is a system and method for reducing exhaust particulate emissions. The present shield prevents large oil droplets in close proximity to the oil separator from easily entering the element, thus preventing less saturation of the oil separator and increasing the efficiency of the oil separator. As a result, environmental pollution is reduced.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Nonprovisional Patent Application, which claims benefit to U.S. Provisional Application Ser. No. 61/365,894 entitled “Heavy Particle Oil Separator Splash Shield,” filed Jul. 20, 2010, the complete disclosure thereof being incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This disclosure relates to reduction in exhaust particulate emissions from a locomotive diesel engine, and specifically to a heavy particle oil separator splash shield. 
       BACKGROUND OF THE DISCLOSURE 
       [0003]    The present disclosure relates to reduction in exhaust particulate emissions from a locomotive diesel engine, and specifically to a heavy particle oil separator splash shield. 
         [0004]    Oil separators are designed to trap and recover small oil droplets and particulate matter from vapors emitted from engines. Specifically, the crankcase ventilation oil separator is used to prevent the build-up of combustible gases in the crankcase, by collecting oil and particulate matter from vapors. 
         [0005]    Cam shaft drive gears and counterweights are generally located in close proximity to the passage leading to the oil separator. The cam shaft drive gears are lubricated through a system of oil passages within the crankcase and manifolds which mount or connect to the mounting shafts for the gears. Oil passing through the gears is splashed around and on to the gears to create the necessary lubrication between the mating gear teeth. This splashing causes heavy particle liquid oil droplets to enter directly into the passage to the oil separator from the crankcase. The purpose of the oil separator is to collect oil and particulate matter from vapors that pass through its element. Therefore, additional oil splashed into the separator from the cam shaft drive gears decreases the efficiency of the element of the oil separator, thus allowing more particulate matter to be released into the atmosphere. 
         [0006]    Thus, it is an object of the present disclosure to provide a shield between the moving parts of the engine (including the cam shaft drive gears) and the oil separator filter to prevent heavy particulate oil droplets from saturating the oil separator. Specifically, the present shield minimizes heavy particle oil droplets in close proximity to the oil separator from entering the filter, thus preventing saturation of the oil separator element and increasing the efficiency of the oil separator. As a result, environmental pollution is reduced. 
         [0007]    The following description is presented to enable one of ordinary skill in the art to make and use the disclosure and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment and the generic principles and features described herein will be readily apparent to those skilled in the art. For instance, although described in the context of a two-stroke diesel engine, the present device may be employed in any diesel engine. Thus, the present disclosure is not intended to be limited to the embodiments shown, but is to be accorded the broadest scope consistent with the principles and features described herein. 
       SUMMARY 
       [0008]    The present disclosure generally relates to a locomotive diesel engine and, more particularly, to a heavy particle oil separator splash shield. Specifically, provided is a system and method for reducing exhaust particulate emissions. The present shield minimizes heavy particle oil droplets from the cam shaft drive gears from entering the oil separator. As a result, the present shield minimizes saturation of the oil separator, thereby increasing the efficiency of the oil separator and reducing environmental pollution. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of a locomotive. 
           [0010]      FIG. 2  is a system diagram of a locomotive diesel engine having a conventional air system. 
           [0011]      FIG. 3  is a partial cross-sectional view of a locomotive diesel engine. 
           [0012]      FIG. 4  is a cross-sectional view of a positive pressure zone of a diesel engine. 
           [0013]      FIG. 5  is a cross-sectional view of a negative pressure zone of a diesel engine. 
           [0014]      FIG. 6  is a partial perspective view of a locomotive diesel engine of  FIG. 3 . 
           [0015]      FIG. 7  is a perspective view of an oil separator assembly for a diesel engine. 
           [0016]      FIG. 8  is another perspective view of an oil separator assembly for a diesel engine. 
           [0017]      FIG. 9  is a perspective view of the opening defined in the mounting flange on turbocharger housing leading to the oil separator. 
           [0018]      FIG. 10  is a perspective view of the mounting location of the present splash shield. 
           [0019]      FIG. 11   a  is a side perspective view of the mounting location of the present splash shield of  FIG. 10 . 
           [0020]      FIG. 11   b  is a side view of the mounting location of the present splash shield of  FIG. 10 . 
           [0021]      FIG. 11   c  is another side perspective view of the mounting location of the present splash shield of  FIG. 10 . 
           [0022]      FIG. 11   d  is a detailed front side view of the mounting location of the present splash shield of  FIG. 10 . 
           [0023]      FIG. 12  is a front perspective view of an embodiment of the present splash shield. 
           [0024]      FIG. 13  is a side perspective view of an embodiment of the present splash shield. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    The present disclosure relates to reduction in exhaust particulate emissions from a locomotive diesel engine, and specifically to a heavy particle oil separator splash shield. The oil splash shield reduces the amount of heavy particle oil splashed from a cam shaft drive gear into the oil separator, thereby reducing engine exhaust particulate matter emissions. Specifically, a splash shield is positioned between the moving parts of the engine (including a cam shaft drive gear) and the oil separator to prevent direct path flow of heavy droplets into the oil separator such that excess oil does not saturate the element of the oil separator. 
         [0026]      FIGS. 1-3  illustrate the present locomotive diesel engine generally comprising a turbocharger  100  having a compressor  102  and a turbine  104  which provides compressed air to an engine  106  having an airbox  108 , power assembly  110 , an exhaust manifold  112 , and a crankcase  114 . In a typical locomotive diesel engine, the turbocharger  100  increases the power capability of the engine  106  by pressurizing and increasing the amount of air transferred to the engine  106 . More specifically, the turbocharger  100  draws air from the atmosphere  116  which is filtered using a conventional air filter  118 . The filtered air is pressurized by a compressor  102 . The compressor  102  is powered by a turbine  104 . A larger portion of the compressed air is transferred to an aftercooler  120  (or otherwise referred to as a heat exchanger, charge air cooler, or intercooler) where the compressed air is cooled to a select temperature. Another smaller portion of the compressed air is transferred to a crankcase ventilation oil separator  122  (or otherwise referred to as an oil separator or lube oil separator) which evacuates the crankcase  114  in the engine  106 , entrains crankcase gas and filters entrained crankcase oil before release into the atmosphere  116 . 
         [0027]    The engine  106  is divided into two distinct pressure zones: positive pressure  151  (above atmospheric pressure) and negative pressure  153  (below atmospheric pressure). The positive pressure zone  151  of a diesel engine  106  is illustrated in  FIG. 4 , whereas the negative pressure zone  153  of a diesel engine  106  is illustrated in  FIG. 5 . The engine  106  may include an eductor system to keep the crankcase  114  at a negative pressure whenever the engine is running. The top deck area of the engine is common to the engine sump through oil drain tubes, and the entire assembly is kept at negative pressure. Blower-equipped engines draw the crankcase  114  vapors through an oil separator  122  into the blower inlet. Turbocharger-equipped engines use an eductor (venturi) tube in the exhaust stack to draw the vapors through the oil separator  122  and expel them into the atmosphere. 
         [0028]    The oil separator  122  is generally configured to trap and recover small oil droplets and particulate matter carried out through vapors from the crankcase. Specifically, the crankcase ventilation oil separator  122  is used to prevent the build-up of combustible gases in the crankcase  114 , by collecting oil and particulate matter from the vapors that flow through it. As shown in  FIGS. 6-8 , in one embodiment, the oil separator  122  includes an elbow-shaped cylindrical housing containing a wire mesh screen element (not shown). However, any type of oil separator may be used. The oil separator  122  is mounted on the turbocharger mounting flange  111 . The elbow assembly connects the oil separator  122  to the eductor tube assembly  126  in the exhaust stack  124 . The eductor tube  126  in the exhaust stack  124  creates a suction which draws up vapor from the crankcase  114  through the separator element. The oil and particulate matter collects on the element and drains back to the crankcase  114 . The remaining gaseous vapor, generally free of oil and particulate matter, is discharged into the exhaust and vented to the atmosphere. 
         [0029]    As described above, and further illustrated in  FIG. 9 , cam shaft drive gears  117  and counterweights are generally located in close proximity to the passageway  115  leading to the oil separator  122 . The cam shaft drive gears  117  are lubricated through a system of oil passages within the crankcase and manifolds which mount or connect to the mounting shafts for the gears. Oil passing through the gears  117  is splashed around and on to the gears  117  to create the necessary lubrication between the mating gear teeth. This splashing causes liquid oil droplets to enter directly into the connection joint or passageway  115  to the oil separator  122 , which contaminate and saturate the element of the oil separator  122  more quickly and more heavily. The purpose of the oil separator  122  is to collect oil and particulate matter from vapors that pass through its element. Therefore, additional oil splashed into the separator from the cam shaft drive gears decreases the efficiency of the element of the oil separator  122 , thus allowing more particulate matter to pass through with the vapors and into the atmosphere. 
         [0030]    In the present system, an oil splash shield  101  is provided from minimizing transfer of heavy oil droplets from the cam shaft drive gears  117  to the oil separator  122  of the locomotive diesel engine (e.g., as shown in  FIGS. 10-13 ). In this system, the engine  106  includes a passageway  115  for allowing vapor to flow from the crankcase  114  to the oil separator  122  for filtration. Specifically, vapor flows from the crankcase  114  to the passageway  115 , via an opening  113  defined in the turbocharger mounting flange  111 , and enters the oil separator  122 . The oil splash shield  101  is situated adjacent to the mounting flange  111  leading to the oil separator  122 , such that the shield deflects splashing heavy oil droplets from the cam shaft drive gears  117  away from the oil separator  122  and back onto the cam shaft gears  117 . More specifically, the present shield  101  is situated adjacent to the opening  113  of the mounting flange  111  and is affixed to the housing  135  of the crankcase  114 . This placement of the shield  101  generally prevents large oil droplets, splashed from the engine in close proximity to the oil separator  122 , from contaminating and saturating the oil separator  122  element. 
         [0031]    In one embodiment, as shown in  FIGS. 10-13 , the present shield  101  is comprised of a member  131  that is selectively sized and shaped such that it extends the near a portion of the opening  113  (and preferably the entire area of the opening  113 ) of the mounting flange  111 , which leads to the oil separator  122 . Although shown in this embodiment to be a U-shaped plate, the member  131  may be any comparable shape. The present shield  101  further includes a mounting element  119  for affixing the shield  101  to the housing  135  of the crankcase. The mounting element  119  defines a plurality of apertures  127 . Each aperture  127  may receive a fastening mechanism, such as a bolt, for affixing the shield to the housing  135  of the crankcase. The mounting element  119  is generally L-shaped and situated in relation to the member  131  to provide adequate support for the member  131 . When the mounting element  119  is affixed to the housing  135 , the member  131  is mounted such that it extends away from the crankcase  114  and gears  117 , as illustrated in  FIGS. 11   a - 11   d.    
         [0032]    Moreover, the member  131  is situated in relation to the moving parts of the engine (e.g., the cam shaft drive gears  117 ) such that it prevents flow of heavy particle oil droplets into the oil separator. Specifically, the member  131  is situated in the passageway between the crankcase  114  and oil separator  122  such that the shield  101  deflects splashing heavy oil droplets from the cam shaft drive gears  117  away from the oil separator  122 . The member  131  is positioned such that it is set away from (that is, not flush with) the opening  113  of the mounting flange  111  leading to the oil separator  122 . As a result, there is a clearance defined between the opening  113  of the mounting flange  111  and the shield  101 . This clearance is sized and shaped such that vapor flow is maintained from the crankcase  114  to the oil separator  122  such that the efficiency of the oil separator  122  is not compromised by the presence of the shield  101 . Thus, the member  131  prevents heavy particle oil droplets from saturating the element, while the larger aperture allows vapor to enter the oil separator  122 . Because the oil separator  122  element is not oversaturated with extraneous heavy particle oil droplets from the cam shaft drive gear  117 , it is able to more efficiently separate oil from the passing vapor. As a result, particulate emissions are reduced. 
         [0033]    Additionally, the shield  101  may further include a plurality of support members  123  for maintaining the rigidity of the shield  101 . In the embodiment shown in  FIGS. 10-13 , the support members  123  are in the form of support triangles; however, they may be any comparable shape. Specifically, the support members  123  maintain the L-shape of the mounting element  119  and secure the positioning of the member  131 . 
         [0034]    In applications that cause back pressure in the exhaust system, such as exhaust silencers or extended exhaust piping runs, an air ejector system is used to increase crankcase vacuum. In this system, pressurized air from the left bank aftercooler duct is piped to the ejector, where it blows through a venturi, adding to the suction created by the eductor tube. Different size ejector nozzles may be used to aid in maintaining proper crankcase suction levels. To increase crankcase suction, a large diameter nozzle is applied, after the engine is inspected for other causes of low vacuum. Oil droplets and particulate matter collect in the oil separator, and drain back to the crankcase, while the vapors discharge, generally free of oil and particulate matter, into the exhaust and are vented to the atmosphere. 
         [0035]    The present disclosure has been described in accordance with the embodiments shown, and one of ordinary skill in the art will readily recognize that there could be variations to the embodiments, and any variations would be within the spirit and scope of the present disclosure. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.