Abstract:
The present disclosure provides an engine cooling system. The engine cooling system includes a first heat exchanger receiving a first fluid and a second heat exchanger receiving a second fluid. The second heat exchanger is located adjacent the first heat exchanger, thereby creating a stacked heat exchanger. The engine cooling system also includes a third heat exchanger receiving a third fluid. The third heat exchanger is located apart from the stacked heat exchanger. A venturi is located between the stacked heat exchanger and the third heat exchanger. An air mover is mounted to the venturi and located within the venturi. The air mover is configured to move air through the stacked heat exchanger and through the third heat exchanger. In a specific embodiment, the engine cooling system is incorporated into a vehicle, such as a skidder vehicle.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates generally to an engine cooling system. In a specific embodiment, the present disclosure relates to a skidder machine having an engine cooling system with an enclosed fan. 
       BACKGROUND 
       [0002]    Many types of machines and vehicles use an engine for motive power, and rely upon a radiator and an air circulation fan to assist in cooling the engine. The engine, radiator and fan are typically positioned within a housing that includes an air intake screen and an outlet opening. During normal operations, the fan draws air into the housing through the air intake screen, directs the air through the radiator and out of the housing through the outlet opening. 
         [0003]    Legislation mandating a reduction in engine noise, engine emissions, and a variety of other engine byproducts has forced manufacturers of machines and vehicles to develop a host of equipment, such as noise suppressors and clean emission modules, to interface with the engine to comply with the respective legislation. Such equipment is generally situated in an engine compartment of the machine and takes up a large amount of space in that compartment or requires a larger engine compartment. However, increasing the size of the engine compartment generally reduces visibility for an operator using the machine. Thus, it is generally desirable to have a smaller engine compartment, thereby allowing the user of the machine to have better operational visibility. 
         [0004]    U.S. Pat. No. 3,203,499 (the &#39;499 patent) addresses the issue of a lack of sufficient space in the engine compartment by disclosing a cooling arrangement for supercharged engines. The &#39;499 patent provides a vehicle having a cooling arranged on the front end of the vehicle. The cooling arrangement provides a cooling means in the form of a radiator and an intercooler mounted in substantially parallel relationship on the sides of the vehicle. Ambient air may be drawn through the cores of the intercooler and out through those of the radiator by means of a fan arrangement situated between the intercooler and the radiator. Unfortunately, the &#39;499 patent does not teach what to do if more than two features (e.g., 1-the supercharger intercooler and 2-the engine radiator) of the vehicle need cooling. 
         [0005]    Accordingly, the present disclosure provides an engine cooling system configured to address one or more of the problems discussed above. 
       SUMMARY OF THE INVENTION 
       [0006]    In one aspect, the present disclosure provides an engine cooling system. The engine cooling system includes a first heat exchanger receiving a first fluid and a second heat exchanger receiving a second fluid. The second heat exchanger is located adjacent the first heat exchanger, thereby creating a stacked heat exchanger. The engine cooling system also includes a third heat exchanger receiving a third fluid. The third heat exchanger is located apart from the stacked heat exchanger. A venturi is located between the stacked heat exchanger and the third heat exchanger. An air mover is mounted to the venturi and located within the venturi. The air mover is configured to move air through the stacked heat exchanger and through the third heat exchanger. In a specific embodiment, the engine cooling system is incorporated into a vehicle, such as a skidder vehicle. 
         [0007]    In another aspect, the present disclosure provides a vehicle. The vehicle includes a frame, an engine supported by the frame, and a drive train. The drive train is configured to propel the machine using power from the engine. An engine cooling system is in fluid communication with the engine. The engine cooling system includes a low ΔT heat exchanger and a high ΔT heat exchanger. The high ΔT heat exchanger is located apart from the low ΔT heat exchanger. A venturi is located between the low ΔT heat exchanger and the high ΔT heat exchanger. The venturi is nested with a drive shaft portion of the drive train. An air mover is located within the venturi. The air mover is configured to move air through the low ΔT heat exchanger and then through the high ΔT heat exchanger at a direction substantially normal to the drive shaft. 
         [0008]    In yet another aspect, the present disclosure provides a skidder machine. The skidder machine includes a frame, an engine supported by the frame, and a drive train configured to propel the machine using power from the engine. The skidder machine further includes a grapple system mounted to the frame. The grapple system is configured to clinch objects, such as downed trees, using power from the engine and to tow the objects as the skidder machine is propelled. The skidder machine further includes an engine cooling system in fluid communication with the engine. The engine cooling system includes a first heat exchanger receiving a first fluid, and a second heat exchanger receiving a second fluid and located adjacent the first heat exchanger, thereby creating a stacked heat exchanger. The engine cooling system further includes a third heat exchanger receiving a third fluid and is located apart from the stacked heat exchanger. A venturi is located between the stacked heat exchanger and the third heat exchanger. An air mover is mounted to the venturi and is located within the venturi. The air mover is configured to move air through the stacked heat exchanger and through the third heat exchanger. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  illustrates a side view of an embodiment of a skidder machine including an engine cooling system according to the present disclosure. 
           [0010]      FIG. 2  illustrates a front view of the skidder machine of  FIG. 1 . 
           [0011]      FIG. 3  illustrates a perspective view of an embodiment of an engine cooling system for the skidder of  FIGS. 1 &amp; 2 . 
           [0012]      FIGS. 4-7  illustrate partial cutaway views of the engine cooling system of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    The present disclosure relates generally to an engine cooling system. In a specific embodiment, the present disclosure relates to a skidder machine having an engine cooling system with an enclosed fan. 
         [0014]      FIG. 1  illustrates a side view of an embodiment of a skidder machine  10  including an engine cooling system  12  according to the present disclosure.  FIG. 2  illustrates a front view of the skidder machine of  FIG. 1 . While the main embodiments of the present disclosure are described generally for a skidder machine  10 , it should be understood that the engine cooling system  12  disclosed herein can be used with engines for other machines (e.g., wheel loaders, track-type tractors, &amp; etc.), vehicles (e.g., cars, trucks, &amp; etc.), industrial engines (e.g., power generating systems, pumping systems, &amp; etc.), locomotives, and anywhere else engine cooling systems are used. 
         [0015]    The skidder machine  10  has a frame  14  supporting an engine  16 . The engine  16  is a reciprocating diesel engine. However, other types of engines such as gasoline, natural gas, or propane reciprocating engines, turbine engines, or rotary engines may be used with the engine cooling system  12  of the present disclosure. The engine  16  is cooled using the engine cooling system  12 . The engine  16  propels the skidder machine  12  using a drive train (e.g., a transmission, an engine drive shaft, a transmission drive shaft, a differential gear box, and etc.). The drive train passes energy to one or more wheels  18  through an axle assembly  20 , which, in turn, propels the skidder machine  12 . 
         [0016]    In an alternative embodiment, the engine  16  may provide power to one or more wheels  18  via a hydraulic pump (not shown), a pressurized fluid (not shown), and one or more fluid operated hydraulic motors (not shown). In yet another alternative embodiment, the engine  16  may provide power to one or more wheels  18  by driving an electric generator (not shown), which drives one or more electric motors (not shown), wherein the electric motor(s) drive the wheels  18 . 
         [0017]    The frame  14  is an articulating frame and pivots at a pivot point  22 , enabling the skidder machine  12  to turn. An operator generally controls operations of the skidder machine  12  from an operator station  24 . Because the skidder machine  10  is likely to be used during forestry operations, the skidder machine  10  may have one or more guards  26  to protect the operator station  24  from falling trees and debris. 
         [0018]    Coupled to the frame  14  is a grapple system  28 . The grapple system  28  includes a lift boom  30  and a plurality of hydraulically actuated arms  32  pivotably mounted to the lift boom  30 . The arms  32  may be actuated to open and close to clench or grasp items such as fallen trees/logs. The grapple system  28  may be coupled to a winch system for locating the lift arms  32  with respect to the lift boom  30 . The lift boom  30  may then be operated to raise the grapple system  28  to ease transportation of the clinched items. In an alternative embodiment, the skidder machine  10  may be configured with a cable winch system (not shown) for clinching items for transport. 
         [0019]    In an embodiment, the skidder machine  10  also has a decking blade  34 . The decking blade  34  pivots with respect to the frame  14  to be raised and lowered. In a lowered position, the decking blade  34  may be used to push out stumps and/or otherwise clear a ground surface as the skidder machine travels in a forward direction (e.g., moving in a direction from the grapple system  28  toward the decking blade  34 . 
         [0020]      FIG. 3  illustrates a perspective view of an embodiment of the engine cooling system  12  for the skidder machine  10 . As can be seen, the cooling system  12  is attached to the frame  14  and is also nested over an engine drive shaft  36  such that and air flow (represented by arrows  38 ) through the cooling system  12  is generally perpendicular or normal to the drive shaft  36  and generally parallel to the axle  20 . However, it should be understood that the air flow  38  may flow in directions other than that shown. In addition, the air flow  38  may be temporarily reversed at times to clean the engine cooling system  12  by blowing out particles that may have lodged into a side of the cooling system  12 . 
         [0021]    The cooling system  12  includes multiple heat exchangers (described in more detail below) spaced apart in a substantially parallel relationship having an air mover, such as a reversible hydraulic motor with a fan blade, (described in more detail below) enclosed within a venturi  40  between the multiple heat exchangers. The venturi  40  supports the air mover and provides a substantially closed air path for air moved by the air mover through each of the heat exchangers. In an embodiment, the venturi  40  is formed from molded fiberglass using multiple sections  41 ,  42 ,  43 ,  44 , which are fastened together. Venturi sections  41  and  43  include air mover mounting pads  46  formed into the venturi section  41  and  43 . Other materials and shapes are contemplated for the venturi  40 . 
         [0022]    Heat exchanger guards  48  and  50  generally encompass the heat exchangers radially to provide a mounting and support system for the heat exchangers and to protect the heat exchangers. The heat exchanger guards  48  and  50  fasten to the venturi  40  to support to the venturi  40  and the air mover. In an embodiment, a pivoting system (e.g., a hinge)  52  is attached to the heat exchanger guard  48 . The pivoting system  52  is also attached to one or more heat exchangers. With this pivoting arrangement, the attached heat exchanger(s) are configured to pivot out, away from the air mover and the venturi  40 , allowing access inside the venturi  40  for cleaning, maintenance, and/or other purposes. The heat exchanger guards  48  and  50  also fasten to mounting plates  54 , which fasten to the frame  14 . 
         [0023]    The heat exchanger guards  48  and  50  also provide a mounting location for other devices, such as a surge tank system  56 , which provides overflow cooling fluid capacity to an engine coolant radiator  58 . The surge tank  56  may be located above the coolant level in the engine coolant radiator  58 . The surge tank  56  may be nested into the natural curve of the venturi  40 , which reduces an overall height of the cooling system  12 . In an embodiment, the heat exchanger guards  48  and  50  may provide expansion slots to absorb natural expansion in the heat exchanger guards  48  and  50  as they increase in temperature during operation of the engine  16 . 
         [0024]    Heat exchangers of the present disclosure, such as the engine coolant radiator  58 , are fin-tube heat exchangers allowing fluid to flow through tubes (not shown) of the heat exchanger while the fins (not shown) radiate heat from the fluid to the air passing through the heat exchanger. For example, heated engine cooling fluid flows from the engine  16  into the engine coolant radiator  58  at the inlet/heated fluid tube  62 . Then, after being cooled, the cooled fluid flows from the outlet/cooled fluid tube  64  back to the engine  16 . Other heat exchangers of the present disclosure discussed below may similarly radiate heat from a heated fluid to air passing through the respective heat exchanger. It is also contemplated that in alternative embodiments one or more of the heat exchangers of the present disclosure may be heat exchangers other than fin-tube type heat exchangers. 
         [0025]    As can be seen in  FIG. 3 , the engine cooling system  12  is configured such that neighboring parts, such as the engine fly wheel bell housing (shown in partial)  66  can be located in a nested or mating fashion. In other words, the shape, size and locations of the venturi  40  and heat exchangers (e.g.,  58 ) allow for the engine cooling system  12  to be located closer to and over a portion of the drive train such as the engine flywheel bell housing  66 , the engine drive shaft  36 , a transmission gear box  68 , the axle  20  and/or other drive train components. As such, the engine compartment may be decreased in size, thereby providing better visibility for the operator. In another embodiment, the engine compartment is also able to provide good user visibility and still contain additional components such as a clean emission module. 
         [0026]      FIGS. 4-7  illustrate partial cutaway views of the engine cooling system  12 .  FIG. 4  shows a cutaway view of the engine cooling system  12  along the line  4 - 4  of  FIG. 3 . This view illustrates the sections  41 ,  42 ,  43 ,  44  of the venturi  40  enclosing air mover  70  assembly. The air mover  70  includes a motor  72  attached to a fan blade assembly  74 . The motor  72  is a reversible hydraulic motor controlled to run at various speeds by a hydraulic fluid from the skidder machine  10 &#39;s hydraulic system (not shown). An electronic controller device  76  varies a flow of the hydraulic fluid to the motor  72  using a varying flow hydraulic valve  78 . The controller device  76  may use a look-up table stored on non-transitory computer readable medium to adjust the motor  72  to run at a desired speed to meet the cooling needs of all associated heat exchangers. The look-up table may include data such as motor revolutions per minute (RPM), air flow cubic feet per minute (CFM), ambient air temperature, humidity, cooling fluid temperature(s), engine operating conditions, and a variety of other data. 
         [0027]    A stationary or stator portion of the motor  72  mounts to a mounting bracket  80  (e.g., a welded wire mounting bracket), which, in turn, mounts to the mounting pads  46  on the venturi  40 . As a rotor portion of the motor  72  rotates, the fan blade assembly  74  also rotates. The rotation of the fan blade assembly  74  pulls air through the venturi  40 . Having the venturi  40  sized to closely follow the path of the fan blade assembly  74 , the air mover  70  can operate efficiently and reduce radial losses at the tips of the fan blades  74  which are common with traditional engine cooling packages. 
         [0028]    In addition to the engine coolant radiator  58 , the engine cooling system  12  may include various other heat exchangers, such as a charge air cooler  82 , an air conditioner condenser  84 , a hydraulic fluid cooler  86 , and/or a fuel cooler  88 . The charge air cooler  82  receives and cools compressed air from a turbo charger (not shown) causing the air to become denser than the previously heated compressed air. When the air is denser, it has more oxygen per unit of volume and, as such, facilitates better engine combustion. The air conditioner condenser  84  provides cooling to an air conditioner system (not shown) refrigerant to provide cooling to the operator station  24 . The hydraulic fluid cooler  86  provides cooling to the skidder machine  10 &#39;s hydraulic system fluid. 
         [0029]    In an embodiment, the charge air cooler  82 , the air conditioner condenser  84  and the hydraulic fluid cooler  86  are stacked adjacent one another (e.g., a stacked heat exchanger) causing the air flow  38  to pass substantially in parallel through these heat exchangers  82 ,  84 , and  86 . Conversely, in an embodiment, the fuel cooler  88  and the engine coolant radiator  58  are layered such that a portion of the air flow  38  that passes through the engine coolant radiator  58  also passes through the fuel cooler  88 . It should be understood that the heat exchangers  58 ,  82 ,  84 ,  86 ,  88 , and/or other heat exchangers may be arranged in a different formation. 
         [0030]    In an embodiment, the air conditioner condenser  84  attaches to the pivoting system  52  and swings out and away from the air mover  70 . A corresponding latch system  85  is provided to keep the air conditioner condenser  84  in a closed position during normal operation. To accommodate the pivoting of the air conditioner condenser  84 , fluid (e.g., refrigerant) lines (not shown) providing fluid to and from the air conditioner condenser  84  are flexible fluid lines (e.g., hoses), which pivot or flex with the air conditioner condenser  84 . 
         [0031]    Generally, the heat exchangers  82 ,  84 , and  86  on fresh air side of the engine cooling system  12  are considered low AT heat exchangers because they have a relatively low temperature differential that they are trying to achieve. Conversely, the heat exchangers  58  and  88  on the pre-heated air side of the engine cooling system  12  are considered high AT heat exchangers because they have a relatively high temperature differential that they are trying to achieve and are thus, more accepting of pre-heated air. 
         [0032]      FIG. 5  shows a cutaway view of the engine cooling system  12  along the line  5 - 5  of  FIG. 3 .  FIG. 6  shows a cutaway view of the engine cooling system  12  along the line  6 - 6  of  FIG. 3 . In addition to the components discussed above,  FIGS. 5 and 6  show a hydraulic fluid tank  90 , which is used as a reservoir to supply hydraulic fluid to and from the skidder machine  10 &#39;s hydraulic system.  FIGS. 5 and 6  also show the engine  16  and other drive train components nested adjacent the engine cooling system  12 . A portion of a transmission system  92  that propels the skidder machine  10  using power from the engine  16  via the engine drive shaft  36  and in turn, provides power to the axle assembly  20  at a differential gear assembly via a transmission drive shaft  94 . A clean emission module (CEM) mounting bracket  96  fastens to the engine  16  block and nests with the curvature of the venturi  40 . The CEM (not shown) mounts on the CEM mounting bracket  96  above the engine  16 .  FIG. 7  shows a cutaway section of the engine cooling system  12  at a lower portion of the cooling system  12  along line  7 - 7  of  FIG. 3 . 
       Industrial Applicability 
       [0033]    The present disclosure relates generally to an engine cooling system. In a specific embodiment, the present disclosure relates to a skidder machine  10  having an engine cooling system  12  with an enclosed fan air mover  70 . The air mover  70  pulls fresh air through the heat exchangers  82 ,  84  and  86  and then pushes that air (now pre-heated air) through heat exchangers  58  and  88 . With the air mover  70  enclosed within the venturi  40 , there is no need for an additional screen around the air mover  70 . 
         [0034]    As can be seen in the figures, the engine cooling system  12  is configured such that neighboring parts, such as the engine fly wheel bell housing  66  can be located in a nested or mating fashion. In other words, the shape, size and locations of the venturi  40  and heat exchangers  58 ,  82 ,  84 ,  86 , and  88  allow for the engine cooling system  12  to be located closer to and over a portion of the drive train such as the engine flywheel bell housing  66 , the engine drive shaft  36 , the transmission gear box  68 , the axle  20  and/or other drive train components. As such, the engine compartment may be decreased in size, thereby providing better visibility for the operator. In another embodiment, the engine compartment is also able to provide good user visibility and still enclose a clean emission module. 
         [0035]    The heat exchangers  82 ,  84 , and  86  on fresh air side of the engine cooling system  12  are considered low AT heat exchangers because they have a relatively low temperature differential that they are trying to achieve. Conversely, the heat exchangers  58  and  88  on the pre-heated air side of the engine cooling system  12  are considered high ΔT heat exchangers because they have a relatively high temperature differential that they are trying to achieve and are thus, more accepting of pre-heated air. 
         [0036]    The rotation of the fan blade assembly  74  pulls air through the venturi  40 . Having the venturi  40  sized to closely follow the path of the fan blade assembly  74 , the air mover  70  can operate efficiently and reduce radial losses at the tips of the fan blades  74  which are common with traditional engine cooling packages. 
         [0037]    In an embodiment, the charge air cooler  82 , the air conditioner condenser  84  and the hydraulic fluid cooler  86  are stacked adjacent one another causing the air flow  38  to pass substantially in parallel through one of these heat exchangers  82 ,  84 , and  86 . Conversely, in an embodiment, the fuel cooler  88  and the engine coolant radiator  58  are layered such that a portion of the air flow  38  that passes through the engine coolant radiator  58  also passes through the fuel cooler  88 . 
         [0038]    It should be understood that the above description is intended for illustrative purposes only. In particular, it should be appreciated that all methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. 
         [0039]    While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present invention as determined based upon the claims below and any equivalents thereof.