Patent Publication Number: US-10309277-B2

Title: Tank for dry sump lubrication system

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to a dry sump lubrication system for an internal combustion engine. More particularly, the disclosure relates to a tank having an integrated filter housing for the dry sump lubrication system for the internal combustion engine. 
     BACKGROUND 
     Engines either include a wet sump lubrication system or a dry sump lubrication system for lubricating various engine components. In the wet sump lubrication system, lubricating oil is stored within the engine in an oil pan that is disposed below a crankcase of the engine. However, storing the lubricating oil within the engine may cause an increase in an overall size of the engine. Due to the increased size of the engine, an assembling of the engine may be difficult in constrained spaces. 
     To overcome such space constraints, the dry sump lubrication system may be applied. In the dry sump lubrication system, the lubricating oil is stored in a reservoir or a tank, which is separate from a sump portion of the crankcase of the engine. Such a tank is generally located externally to the engine. During operation of the engine, the lubricating oil is pumped from this tank to the engine and is returned to the tank. However, the dry sump lubrication system may include additional components that may add to the cost and complexity of the engine. 
     WIPO Application 2012171620 relates to an oil tank for a motor vehicle with dry sump lubrication. The oil tank includes two components which define a closed hollow space for accommodating an oil. The first component is a cast component and the second component is a sheet metal component. 
     SUMMARY OF THE INVENTION 
     In one aspect, the disclosure is directed towards a tank for a dry sump lubrication system for an internal combustion engine. The tank includes a body having a first portion, a second portion, and defines an inner chamber. The tank also includes a filter housing integrally formed with the first portion and disposed inside the inner chamber. The filter housing is configured to receive a filter. Further, the body and the filter housing are formed by a blow molding process. 
     In another aspect, the disclosure relates to a dry sump lubrication system for an internal combustion engine. The dry sump lubrication system includes a tank that is configured to store a lubricating oil. The tank includes a body having a first portion, a second portion, a filter housing, and a filter. The tank defines an inner chamber. The filter housing is integrally formed with the first portion and is disposed inside the inner chamber. Further, the body and the filter housing are formed by a blow molding process. The filter is disposed inside the filter housing and is configured to filter the lubricating oil received from the internal combustion engine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic and a diagrammatic illustration of an exemplary engine system having an internal combustion engine and a dry sump lubrication system having a tank assembly, in accordance with the concepts of the present disclosure; 
         FIG. 2  is a sectional perspective view of the tank assembly having a tank, in accordance with the concepts of the present disclosure; and 
         FIG. 3  is an exploded sectional view of the tank assembly, in accordance with the concepts of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , there is shown an engine system  100 . The engine system  100  may include an internal combustion engine  102  (or simply an engine  102 ) and a dry sump lubrication system  104 . The engine system  100  may be applied within construction machines, such as off-highway trucks, loaders, tractors, excavators, dozers, loaders, compactors, or any other construction machine, agricultural machine, mining machine, earth moving machine, etc. 
     The dry sump lubrication system  104  may be configured to supply oil, such as a lubricating oil, to the engine  102  and certain associated components of the engine  102 , for lubrication purposes. The dry sump lubrication system  104  may include a tank assembly  106 , a supply conduit  108 , and a pump  110  that is configured to pump the lubricating oil from the tank assembly  106  to the engine  102  via a supply path defined by the supply conduit  108 . A return conduit  112  may also be provided that facilitates a return of a used lubricating oil, back to the tank assembly  106 . In an implementation, a pump  113  may pump the lubricating oil from the engine  102  to the tank assembly  106 . The tank assembly  106  of the dry sump lubrication system  104  is placed remotely from the engine  102 , and is fluidly connected to the engine  102  via the supply conduit  108  and the return conduit  112 . 
     Referring to  FIGS. 2 and 3 , the tank assembly  106  is depicted and discussed. The tank assembly  106  includes a tank  114  that is configured to store the lubricating oil, and a filter  116  that filters the lubricating oil prior to storage within the tank  114 . The tank  114  includes a body  118  that defines an inner chamber  120 , and includes a first portion  122  and a second portion  124 . The tank  114  further includes a filter housing  126  integrally formed with the first portion  122  and extending into the inner chamber  120 . The first portion  122  and the second portion  124  are coupled to each other to form the tank  114  and define the inner chamber  120  of the body  118  of the tank  114 . In an embodiment, the body  118  and the filter housing  126  are formed by a blow molding process. As shown in  FIGS. 2 and 3 , the first portion  122  and the second portion  124  are two different components that are manufactured separately by the blow molding process, and are assembled together to form the tank  114 . In such a case, the filter housing  126  is formed with the first portion  122  during manufacturing of the first portion  122  by the blow molding process. 
     In certain implementations, the first portion  122  may be adapted to be vertically arranged and assembled atop the second portion  124  in one configuration of the tank  114  as shown in  FIGS. 1, 2, and 3 . Such a configuration may define an elevation, E, of the body  118 , which is denoted in  FIG. 2 . Both the first portion  122  and the second portion  124  may include a U-shaped profile. In some implementations, such as in the embodiment depicted in  FIGS. 1, 2, and 3 , the first portion  122  may be assembled atop the second portion  124  in an inverted manner, such that the first portion  122  acquires an inverted U-shaped profile relative to the second portion  124 . Further, the first portion  122  may include a first flange  128  and the second portion  124  may include a second flange  130 . To enable an assembly between the first portion  122  and the second portion  124 , the first flange  128  is fastened and/or coupled to the second flange  130 . To establish such a fastening, bolts, rivets, or other conventionally available fasteners, may be used. Further, a seal, such as a gasket  132 , may be provided between the first flange  128  and the second flange  130  to prevent leakage of lubricating oil from the inner chamber  120 . Alternatively, the tank  114  may be formed by the blow molding process as single unit, having the filter housing  126  integrally formed with the first portion  122  of the body  118 . 
     As shown in  FIGS. 2 and 3 , the second portion  124  includes a side structure  134 , and a bottom structure  136  having a base  138  and one or more side walls extending between the base  138  and the side structure  134 . The one or more side walls may be inclined to both the base  138  and the side structure  134 . In an embodiment, the one or more side walls may include, for example, a first side wall  140  and a second side wall  142 , each extending between the base  138  and the side structure  134 . In an exemplary scenario, the side structure  134  may include one or more walls extending from the bottom structure  136  to the second flange  130 . The one or more walls of the side structure  134  may include, for example, a first wall  144 , a second wall  146 , a front wall  148  (see  FIG. 1 ) extending between the first wall  144  and the second wall  146 , and a back wall  150  facing the front wall  148  and extending between the first wall  144  and the second wall  146 . The first side wall  140  extends from the base  138  to the first wall  144 , and is inclined to both the first wall  144  and the base  138 . Similarly, the second side wall  142  extends from the base  138  to the second wall  146 , and is inclined to both the second wall  146  and the base  138 . As an example, an included angle between the base  138  and the side walls  140 ,  142  may be an obtuse angle. Further, an included angle between the side structure  134  and the side walls  140 ,  142  may also be an obtuse angle. For example, as shown, the included angle between the first side wall  140  and the first wall  144  is an obtuse angle, and the included angle between the second side wall  142  and the second wall  146  is also an obtuse angle. Further, each of the front wall  148  and the back wall  150  may be attached to the base  138 . 
     Further, the second portion  124  may include an outlet passage  160  formed in the base  138  that facilitates an exit of lubricating oil from the inner chamber  120  of the tank  114  into the supply conduit  108 , and in turn into the engine  102  and the engine&#39;s associated components. As the side walls  140 ,  142  are inclined relative to the base  138 , the lubricating oil is directed towards the outlet passage  160  formed in the base  138 , minimizing retention of an unutilized amount of the lubricating oil inside the tank  114 . The outlet passage  160  may be formed during the blow molding process or may be formed by performing a drilling operation on the base  138 . 
     Also, the side structure  134  may include one or more bulged portions to increase a volume of the inner chamber  120 . For example, as shown in  FIG. 1 , the front wall  148  includes a bulged portion  162  to increase a volume of the inner chamber  120 . Although the bulged portion  162  is shown in the front wall  148 , it may be appreciated that similar types of bulged portions may be included in the other walls of the side structure  134 . Also, it may be noted that a size, a shape, and a number of the bulged portions, may depend upon a spatial confine in which the tank  114  is adapted to be accommodated. It may be appreciated that similar bulged portions may also be formed in the first portion  122  of the tank  114 . 
     Again referring to  FIGS. 2 and 3 , the first portion  122  may include a header plate  170  and a wall  172  extending downwardly from the header plate  170 . In an implementation, the wall  172  extends at an inclination to the header plate  170 . Further, the first flange  128  is disposed at an end of the wall  172 , away from the header plate  170 . The header plate  170  may include a fill port  174 , a vent port  176 , and a dipstick opening  178 . The fill port  174  is adapted to facilitate an entry of the lubricating oil into the inner chamber  120 . In an embodiment, the fill port  174  may be formed during the blow molding process of the first portion  122  of the tank  114 . Alternatively, the fill port  174  may be formed by performing a drilling operation on the header plate  170 . Further, the tank  114  may include a fill plug  180  for covering the fill port  174 . To enable a filling of the inner chamber  120  with lubricating oil, the fill plug  180  is removed from the fill port  174 . 
     Further, the vent port  176  is formed in the header plate  170  and facilitates venting of air (or gases) from the inner chamber  120  to an outside of the tank  114 . In an embodiment, the vent port  176  may be formed during the blow molding process of the first portion  122  of the tank  114 . Alternatively, the vent port  176  may be formed by performing a drilling operation on the header plate  170 . In certain implementations, a check valve (not shown) may be positioned in the vent port  176  to regulate an exit of the air (or gases) from the inner chamber  120 , and prevent an entry of air from the atmosphere into the inner chamber  120 . 
     The dipstick opening  178  may be adapted to facilitate an insertion of a dipstick  184  into the inner chamber  120  to measure a level of lubricating oil (or any fluid) stored in the tank  114 , at any given point. In an assembled position of the dipstick  184  with the tank  114 , the dipstick  184  is positioned to extend through the dipstick opening  178 . To check a level of lubricating oil in the inner chamber  120 , an operator may remove the dipstick  184  from the dipstick opening  178  and visually analyze a length of the dipstick  184  on which the lubricating oil is present. In an embodiment, the dipstick opening  178  may be formed during the blow molding process of the first portion  122  of the tank  114 . Alternatively, the dipstick opening  178  may be formed by performing a drilling operation on the header plate  170 . 
     Further, the tank  114  includes an inlet conduit  186  that extends from the first portion  122  of the body  118  of the tank  114  to the filter housing  126 . The inlet conduit  186  facilitates a flow of a lubricating oil from the engine  102  to the filter housing  126 . As shown, a portion of the inlet conduit  186  extends outwardly from the wall  172  and a remaining portion of the inlet conduit  186  extends inwardly from the wall  172  into the inner chamber  120  to the filter housing  126 . The inlet conduit  186  includes an inlet opening  188 , and an outlet opening  190  formed in the filter housing  126 . 
     The filter housing  126  may be disposed inside the inner chamber  120 , and is configured to receive the filter  116 . The filter housing  126  includes a wall  192  extending at least partially from the header plate  170  of the first portion  122  into the inner chamber  120 . The wall  192  may include a cylindrical structure that defines a cavity  194  (see  FIG. 3 ) to house the filter  116 . Further, an aperture  196  is formed in the header plate  170  of the first portion  122  that defines an opening  198  of the cavity  194 . The opening  198  facilitates a removal of the filter  116  from the filter housing  126 . Further, a portion  200  of the wall  192  may extend partially outwardly from the header plate  170 . A cap  202  may be engaged with the portion  200  to cover the opening  198  of the aperture  196 . The cap  202  may be engaged with the portion  200  by a threaded engagement. Alternatively, the cap  202  may be coupled to the portion  200  by a snap fit engagement. In certain implementations, a seal  204  may be positioned between the cap  202  and an upper end  206  or the portion  200  of the wall  192  to prevent egress of the lubricating oil from the filter housing  126 . In an embodiment, the fill port  174  and the corresponding fill plug  180  may be omitted. In such a case, the opening  198  of the filter housing  126  facilitates an entry of the lubricating oil into the inner chamber  120 . To enable a filling of the inner chamber  120  with lubricating oil, the cap  202  is removed from the opening  198  of the filter housing  126 . 
     The filter housing  126  further includes a bottom wall  210  integrally formed at a lower end  208  of the wall  192 . The bottom wall  210  faces the header plate  170  and is substantially perpendicular to the wall  192 . An outlet port  212  is formed into the bottom wall  210  and provides an opening for an exit of a filtered lubricating oil from the filter housing  126  to the inner chamber  120 . 
     The filter housing  126  may further include a bypass conduit  214  that fluidly couples the cavity  194  of the filter housing  126  to the inner chamber  120  of the body  118 . The bypass conduit  214  may extend outwardly from the wall  192  into the inner chamber  120 . In an embodiment, the bypass conduit  214  may include a unidirectional valve (not shown) coupled to the bypass conduit  214 , which allows a quantity of lubricating oil to flow only in one direction—that is from the cavity  194  towards the inner chamber  120 . The unidirectional valve may be check valve that allows an exit of the lubricating oil into the inner chamber  120  when a pressure of the lubricating oil inside the cavity  194  exceeds a threshold value. 
     In one implementation, the body  118  (i. e. both the first portion  122  and the second portion  124 ) and the filter housing  126  may be formed from the same material. For example, the material may include polyamide, fibrous polyamide, high-grade plastic, nylon, and similar such materials. The material may be suitable for storing the lubricating oil at relatively high temperatures. 
     As shown in  FIGS. 2 and 3 , the filter  116  may include a cylindrical structure  220  having an outer surface  222 , and an inner surface  224  defining a space  226  within the filter  116 . The filter  116  is disposed inside the filter housing  126  (i.e. in the cavity  194 ) such that the outer surface  222  of the cylindrical structure  220  faces an inner surface of the wall  192 . The filter  116  may be assembled (or inserted) into the filter housing  126  through the aperture  196  and be seated against the bottom wall  210  for assembly. In an assembled position of the filter  116 , the space  226  is aligned with the outlet port  212  and may be co-axial with the outlet port  212 . The cylindrical structure  220  is formed of a material suitable for filtering the lubricating oil received from the engine  102 . The cylindrical structure is adapted to filter the lubricating oil as the lubricating oil passes through the cylindrical structure  220  from the outer surface  222  to the inner surface  224 . 
     INDUSTRIAL APPLICABILITY 
     During operation, the pump  110  may power a flow of the lubricating oil from the tank  114  to the engine  102  via the outlet passage  160  and the supply conduit  108 . A return of the lubricating oil may be facilitated through the return conduit  112 . During a return, the lubricating oil may travel through the inlet conduit  186  and enter into the cavity  194  of the filter housing  126 , and subsequently into the cylindrical structure  220  of the filter  116  positioned within the filter housing  126 . As the lubricating oil enters the filter housing  126 , the lubricating oil may flow around the filter  116  (in an annular space defined between the wall  192  and the outer surface  222  of the filter  116 ), cause a pressure to build-up in the annular space, and steadily flow into the cylindrical structure  220 , so as to be filtered by the filter  116 . During filtration, lubricating oil may flow across the cylindrical structure  220  of the filter  116 , along a direction lateral to a height of the filter  116  and enter and accumulate into the space  226  of the filter  116 . Since the space  226  of the filter  116  is fluidly coupled to the outlet port  212 , the filtered lubricating oil flows into the inner chamber  120  through the outlet port  212 . As a result, a filtered lubricating oil is received from the filter housing  126  by the inner chamber  120  and is stored by the tank  114  within the inner chamber  120 . 
     On occasions, such as during cold conditions, when a pressure exerted by the lubricating oil on the outer surface  222  of the filter  116  becomes relatively high, the bypass conduit  214  may open (that is the unidirectional valve positioned in the bypass conduit  214  may open) and permit the lubricating oil to bypass the filter  116 . Such a scenario may be contemplated when the lubricating oil becomes more viscous due to temperature of the lubricating oil dropping below a threshold temperature. 
     Given the inclusion and integration of the filter housing  126  within the inner chamber  120 , a need for additional space for the filter housing  126  may be well avoided, making the tank  114  space efficient. Further, as the tank  114  may be formed of plastic and manufactured by the blow molding process, an overall cost of the tank  114  may be reduced. Also, an integration of the filter housing  126  with the body  118  of the tank  114  helps in reducing a cost and complexity associated with the dry sump lubrication system  104 . This is because a separate positioning may include a use of clamps and fixtures to mount the filter  116 , dedicated flow channels to route the lubricating oil flow to and from the filter  116 , and similar such components and accessories, all of which may increase an overall cost and complexity of the dry sump lubrication system  104 .