Patent Publication Number: US-2016222844-A1

Title: Oil pan and engine assembly including the oil pan

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/110,770, filed Feb. 2, 2015, which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to an oil pan and an engine assembly including the oil pan. 
     BACKGROUND 
     An oil pan can collect oil used to lubricate an internal combustion engine. During operation of the internal combustion engine, oil may circulate within the internal combustion engine to lubricate moving components of the internal combustion engine, dissipate thermal energy, and protect against wear of the internal combustion engine. After lubricating the moving parts of the engine, the oil is collected by the oil pan. 
     SUMMARY 
     To maximize fuel efficiency during operation of an internal combustion engine, the oil lubricating the engine should have an optimum oil viscosity. The oil viscosity can be varied by adjusting the temperature of the oil. Accordingly, it is useful to heat or cool the oil in the oil pan in order to adjust the oil viscosity. The presently disclosed engine assembly can heat or cool the oil in the oil pan independently of the oil flowrate generated by an oil pump. In an embodiment, the presently disclosed engine assembly includes an oil pan, which may be casted. The oil pan includes an oil pan body, and the oil pan body includes an inner pan surface and an outer pan surface opposite the inner pan surface. The inner pan surface defines a cavity configured to collect oil. The oil pan further includes a pan passageway (e.g., jacket) extending through the oil pan body. The pan passageway is disposed between the inner pan surface and the outer pan surface. In addition, the pan passageway is configured to carry a heat transfer fluid (e.g., coolant) in order to transfer heat between the oil disposed in the cavity and the heat transfer fluid. The present disclosure also relates to an oil pan as described above and a method for exchanging heat between the oil in the oil pan and the heat transfer fluid flowing through the pan passageway. 
     The above features and advantages and other features and advantages of the present teachings are readily apparent from the following detailed description of the best modes for carrying out the teachings when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic illustration of a vehicle including an engine assembly in accordance with an embodiment of the present disclosure, wherein the engine assembly includes an oil pan; 
         FIG. 2  is a schematic, perspective view of an oil pan shown in  FIG. 1 ; 
         FIG. 3  is a schematic, top view of the oil pan shown in  FIG. 2 ; 
         FIG. 4  is a schematic, cross-sectional view of the oil pan shown in  FIG. 2 , taken by the section line  4 - 4  of  FIG. 3 ; and 
         FIG. 5  is a flowchart of a method for exchanging heat between a heat transfer fluid and oil in the oil pan shown in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings, wherein like reference numbers correspond to like or similar components throughout the several figures,  FIG. 1  schematically illustrates a vehicle  10 , such as a car, including an engine assembly  12 . The engine assembly  12  includes an internal combustion engine  14  configured to propel the vehicle  10 . The internal combustion engine  14  employs oil O for lubrication, among other things. The engine assembly  12  further includes an oil pan  16  coupled to the internal combustion engine  14 . As a consequence, oil O can flow between the internal combustion engine  14  and the oil pan  16 . Specifically, the oil O can lubricate the internal combustion engine  14  and then flows to the oil pan  16 . The oil pan  16  then collects the oil O but the oil O does not rise above a predetermined oil level L. The engine assembly  12  further includes an oil pump  18  coupled to the oil pan  16 . Consequently, the oil pump  18  can move the oil O from the oil pan  16  to another vehicle component  20 , such as an oil gallery. The oil O can then flow back from the vehicle component  20  (e.g., oil gallery) to the internal combustion engine  14 . 
     To maximize fuel efficiency during operation of the internal combustion engine  14 , the oil O should have an optimum oil viscosity. The oil viscosity can be varied by adjusting the temperature of the oil O. Accordingly, it is useful to heat or cool the oil O in the oil pan  16  in order to adjust the oil viscosity. The presently disclosed engine assembly  12  can heat or cool the oil O in the oil pan  16  independently of the oil flowrate generated by the oil pump  18 . This is especially important in the scenario when the internal combustion engine  14  is warming up and the engine speed is relatively low. In this scenario, heating the oil O can decrease its viscosity, thereby minimizing friction in the internal combustion engine  14 . It is projected that, by using the presently disclosed oil pan  16 , the fuel efficiency of the internal combustion engine  14  can be improved by about one (1) to one point five (1.5) percent over conventional engines during the warm up period. 
     The engine assembly  12  further includes a heat transfer fluid source  22  capable of holding heat transfer fluid F. The heat transfer fluid F can be any fluid (e.g., liquid) suitable for transferring heat. As a non-limiting example, the heat transfer fluid F may be a coolant, such ethylene glycol. The fluid source  22  is in fluid communication with an input passageway  24  (e.g., conduit, tube, pipe, etc.). The input passageway  24  is outside the oil pan  16  and is fluidly coupled between the oil pan  16  and the fluid source  22 . Accordingly, the heat transfer fluid F can flow from the fluid source  22  to the oil pan  16 . A fluid transfer pump  26  is also coupled to the input passageway  24  in order to move the heat transfer fluid F from the fluid source  22  to the oil pan  16  through the input passageway  24 . 
     The input passageway  24  is in thermal communication with a heat source  28 . As a consequence, the heat source  28  can heat the heat transfer fluid F flowing through the input passageway  24 . As non-limiting examples, the heat source  28  can be an exhaust manifold, an exhaust gas recirculation system, a turbocharger, an engine block, an engine head, or a combination thereof. Regardless of the kind of heat source  28  used, heat H can be transferred between the heat transfer fluid F flowing through the input passageway  24  and the heat source  28 . 
     The input passageway  24  is in thermal communication with a cooling source  30 . As a consequence, the cooling source  30  can cool the heat transfer fluid F flowing through the input passageway  24 . As a non-limiting example, the cooling source  30  can be the cooling system of the vehicle  10 . Irrespective of the kind of cooling source  30  used, heat H can be transferred between the heat transfer fluid F flowing through the input passageway  24  and the cooling source  30 . 
     As discussed in detail below, the oil pan  16  has a pan passageway  32  (e.g., jacket, hole, opening) formed by the oil pan body  36  and in fluid communication with the input passageway  24 . Accordingly, the heat transfer fluid F can flow between the input passageway  24  and the pan passageway  32 . While flowing through the pan passageway  32 , heat can be transferred between the oil O disposed in the oil pan  16  and the heat transfer fluid F flowing through the pan passageway  32  as discussed below. The engine assembly  12  also includes an output passageway  34  (e.g., conduit, tube, pipe, etc.) outside the oil pan  16 . The output passageway  34  is in fluid communication with the pan passageway  32 . Accordingly, the heat transfer fluid F can flow between the pan passageway  32  and the output passageway  34  once heat has been transferred between the heat transfer fluid F flowing through the pan passageway  32  and the oil O disposed in the oil pan  16 . It is contemplated that the oil pan  16  may include one or more pan passageways  32 . 
     With reference to  FIGS. 2-3 , the oil pan  16  is wholly or partly made of a substantially rigid material, such as a rigid metallic material, and is configured to hold the oil O. It is contemplated that the oil pan  16  can be manufactured by casting. However, other suitable manufacturing methods can be used to make the oil pan  16 . Regardless of the manufacturing method employed, the oil pan  16  includes an oil pan body  36  including a plurality of walls  38 . For example, in the depicted embodiment, the oil pan  16  includes a plurality of sidewalls  38   a  and at least one bottom wall  38   b  interconnecting the sidewalls  38   a.  The oil pan body  36  defines an inner pan surface  40  and an outer pan surface  42  opposite the inner pan surface  40 . The inner pan surface  40  defines an open cavity  44  configured, shaped, and sized to collect and hold the oil O. 
     The pan passageway  32  extends through at least one of the walls  38  and is entirely disposed between the inner pan surface  40  and the outer pan surface  42 . In the depicted embodiment, the pan passageway  32  extends through at least the bottom wall  38   b.  It is envisioned, however, that the pan passageway  32  may also extend through the sidewalls  38   a.  Irrespective of its exact location, the pan passageway  32  is configured to carry the heat transfer fluid F in order to promote heat transfer between the oil O ( FIG. 1 ) disposed in the open cavity  44  and the heat transfer fluid F flowing through the pan passageway  32 . 
     The pan passageway  32  may have a substantially U-shape and has an inlet  46  in fluid communication with the fluid source  22  ( FIG. 1 ) through the input passageway  24  ( FIG. 1 ). Therefore, the heat transfer fluid F can flow between the fluid source  22  and the pan passageway  32 . Further, the pan passageway  32  includes an outlet  48  in fluid communication with the output passageway  34 . Thus, the heat transfer fluid F can flow from the pan passageway  32  to the output passageway  34  after the heat has been transferred between the oil O in the cavity  44  of the oil pan  16  and the heat transfer fluid F flowing through the pan passageway  32 . Because the oil O in the oil pan  16  can be cooled by exchanging heat from the heat transfer fluid F, the engine assembly  12  does not need an oil cooler. Thus, the engine assembly  12  (and therefore the vehicle  10 ) does not have an oil cooler for cooling the oil O in the oil pan  16 . 
     With reference to  FIG. 5 , to heat or cool the oil O in the oil pan  16 , the engine assembly  12  can be used in accordance with the method  100 . The method  100  begins in step  102 . In step  102 , the heat transfer fluid F is heated or cooled before being introduced into the pan passageway  32 . To heat the heat transfer fluid F, heat can be transferred from the heat source  28  (e.g., exhaust manifold) to the heat transfer fluid F while the heat transfer fluid F is flowing through the input passageway  24  as discussed above. To cool the heat transfer fluid F, heat can be transferred from the heat transfer fluid F to the cooling source  30  while the heat transfer fluid F flows through the input passageway  24 . Then, the method  100  proceeds to step  104 . 
     Step  104  entails introducing the heated or cooled heat transfer fluid F into the pan passageway  32  while oil O is disposed in the cavity  44  of the oil pan  16 . At this juncture, the heat transfer fluid F flows through the pan passageway  32  from the inlet  46  to the outlet  48 . While the heat transfer fluid F flows through the pan passageway  32 , heat is transferred between the oil O disposed in the cavity  44  of the oil pan  16  and the heat transfer fluid F flowing through the pan passageway  32  in order to cool or warm up the oil O. Then, the method  100  continues to step  106 . 
     In step  106 , the heat transfer fluid F flows out of the pan passageway  32  through the outlet  48  and into the output passageway  34 . At this point, the heat transfer fluid F may be directed back to the input passageway  24  in order to be recycled. 
     While the best modes for carrying out the teachings have been described in detail, those familiar with the art to which this disclosure relates will recognize various alternative designs and embodiments for practicing the teachings within the scope of the appended claims.