Patent Publication Number: US-8528677-B2

Title: Working vehicle having cooling system

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/163,578, filed Mar. 26, 2009, entitled “WORKING VEHICLE HAVING COOLING SYSTEM,” and U.S. Provisional Patent Application Ser. No. 61/163,584, filed Mar. 26, 2009, entitled “WORKING VEHICLE HAVING COOLING SYSTEM WITH SUCTION DEVICE,” the entire disclosures of each of which are hereby incorporated by reference herein. This application is related to International Application No. PCT/US2010/024681, filed concurrently herewith, and entitled “WORKING VEHICLE HAVING COOLING SYSTEM,” the entire disclosure of which is hereby incorporated by reference herein. This application is related to U.S. Application Ser. No. 12/708,625, filed concurrently herewith, and entitled “WORKING VEHICLE HAVING COOLING SYSTEM WITH SUCTION DEVICE,” the entire disclosure of which is hereby incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates in general to working vehicles, and more particularly, to cooling systems in working vehicles. 
     U.S. Pat. No. 3,636,684 discloses a harvesting machine having a fan 72 which pulls air into an engine enclosure 50 through screens, wherein the air passes through a radiator core 56 prior to exiting the enclosure 50, see column 5, lines 54-59. 
     U.S. Pat. No. 3,664,129 discloses a lift truck including “a hydraulic motor-driven cooling fan, the speed of which is varied with engine temperature,” see column 1, lines 42-44 and column 3, lines 15-20. “The fan blades draw engine-heated air rearwardly through radiator core 18 and push such air through air duct 28 and out through the rear end of the truck,” see column 3, lines 20-22. 
     U.S. Pat. No. 6,959,671 discloses a cooling system for a work vehicle wherein a “rotational speed of the cooling fan 13 actuated by the hydraulic pump 18 is continuously controlled according to the temperature of the coolant, the temperature of the hydraulic oil and the rotational speed of the engine,” see column 5, lines 3-7. The &#39;671 patent also teaches that the direction of the fan may be reversed such that “dust or the like caught in the radiator 12 is blown off by a reverse current of air,” see column 5, lines 24-30. 
     SUMMARY OF THE INVENTION 
     In accordance with a first aspect of the present invention, a work vehicle is provided comprising a main frame including an engine compartment; an engine located in the engine compartment; and a cooling system for removing energy in the form of heat from the engine and transferring that energy to air. The cooling system may comprise a rotating fan apparatus and a cooling assembly. The cooling assembly may comprise a heat exchanger and a filter structure. The heat exchanger may transfer energy in the form of heat from a coolant fluid circulating through the engine to air forced through the heat exchanger by the fan apparatus. The filter structure may be positioned adjacent a first side of the heat exchanger to filter the air before the air passes through the heat exchanger and comprise a support frame and at least one filter element held by the support frame. The support frame may maintain the filter element at an angle relative to vertical. 
     The filter element may comprise a mesh screen. 
     An upper portion of the filter element may be spaced a first distance away from the heat exchanger and a lower portion of the filter element may be spaced a second distance away from the heat exchanger, with the first distance being greater than the second distance. 
     The fan apparatus may comprise a fan and a motor. The motor may effect rotation of the fan in a first direction to pull air from the engine compartment through the heat exchanger to remove heat from the coolant fluid. The fan motor may be capable of reversing direction so as to effect rotation of the fan in a second direction to force air through the filter element to force debris off of the filter element. 
     In accordance with a second aspect of the present invention, a cooling assembly is provided for use in a work vehicle. The cooling assembly may comprise a heat exchanger for transferring energy in the form of heat from a coolant fluid to air passing through the heat exchanger, filter structure positioned adjacent a first side of the heat exchanger to filter the air before the air passes through the heat exchanger, first seal structure located between the filter structure and the heat exchanger to seal an interface between the filter structure and the heat exchanger, a fan shroud positioned adjacent a second side of the heat exchanger, and a second seal structure located between the heat exchanger and the fan shroud. 
     The cooling assembly may further comprise connecting structure to couple together the filter structure, the first seal structure, the heat exchanger, the fan shroud and the second seal structure. 
     The connecting structure may comprise at least one spacer provided with a bore, a bolt passing through the spacer bore and a nut. The bolt may extend through corresponding bores in the filter structure and the fan shroud while the spacer is located between the filter structure and the fan shroud. 
     The filter structure may comprise a support frame and at least one filter element held by the support frame. The filter element may comprise a mesh screen. 
     The support frame may maintain the filter element at an angle relative to vertical. An upper portion of the filter element may be spaced a first distance away from the heat exchanger and a lower portion of the filter element may be spaced a second distance away from the heat exchanger, with the first distance being greater than the second distance. 
     The filter structure may further comprise a third seal structure located between the support frame and the filter element. 
     The cooling assembly may further comprise a main frame seal structure adapted to be located between the fan shroud and a main frame of the work vehicle. 
     In accordance with a third aspect of the present invention, a work vehicle is provided comprising a main frame including an engine compartment; an engine located in the engine compartment; and a cooling system for removing energy in the form of heat from the engine and transferring that energy to air. The cooling system may comprise a rotating fan apparatus and a cooling assembly. The cooling assembly may comprise: a heat exchanger for transferring energy in the form of heat from a coolant fluid circulating through the engine to air forced through the heat exchanger by the fan apparatus; filter structure positioned adjacent a first side of the heat exchanger to filter the air before the air passes through the heat exchanger; first seal structure located between the filter structure and the heat exchanger to seal an interface between the filter structure and the heat exchanger; a fan shroud positioned adjacent a second side of the heat exchanger; and a second seal structure located between the heat exchanger and the fan shroud. 
     The cooling assembly may further comprise connecting structure to couple together the filter structure, the first seal structure, the heat exchanger, the fan shroud and the second seal structure. 
     The cooling assembly may further comprise a main frame seal structure located between the fan shroud and the main frame. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The following description of the preferred embodiments of the present invention can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals, and in which: 
         FIG. 1  is a side view of a vehicle including a cooling system constructed in accordance with the present invention; 
         FIGS. 2 and 3  are exploded views including the cooling system illustrated in  FIG. 1 ; 
         FIG. 4  is a perspective view of the cooling system illustrated in  FIG. 1 ; 
         FIG. 5  is a rear view of a portion of the vehicle illustrated in  FIG. 1 ; 
         FIG. 6  is a side view in cross section of the cooling system and a portion of a vehicle main frame; 
         FIG. 7  is an enlarged cross sectional view of the handle structure illustrated in  FIG. 6 ; 
         FIG. 8  is an enlarged cross sectional view of a recess formed in the support frame illustrated in  FIG. 6 ; 
         FIGS. 9 and 10  are enlarged cross sectional views illustrating the first and second seal structures and the connecting structure shown in  FIG. 6 ; and 
         FIG. 11  is a perspective view illustrating the handle structure pin just before engaging the U-shaped spring clip. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, and not by way of limitation, specific preferred embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and that changes may be made without departing from the spirit and scope of the present invention. 
     Referring now to the drawings, and particularly to  FIG. 1 , a work vehicle, comprising a materials handling vehicle  10  in the illustrated embodiment, is shown and includes a cooling system  100  constructed in accordance with the present invention, see also  FIGS. 2-4 . The materials handling vehicle  10  comprises a main frame  20  including an engine compartment  22  housing an internal combustion engine  23  or a hybrid propulsion system (not shown). Four wheels  24  are coupled to the main frame  20 . At least one of the wheels  24  is driven and at least one is steerable. The vehicle  10  also includes an operator&#39;s compartment  26  including an operator&#39;s seat  26 A and a steering wheel  26 B. A pair of forks  27  are mounted on a fork carriage mechanism  28 , which, in turn, is coupled to an extensible mast assembly  29 . The forks  27 , fork carriage mechanism  28  and mast assembly  29  define a fork assembly  30  coupled to the main frame  20 . As will be discussed further below, the cooling system  100  removes energy in the form of heat from the engine  23  and transfers that energy to air. It is contemplated that the cooling system  100  may also be incorporated into other work vehicles, such as a skid steer loader. 
     In the illustrated embodiment, the cooling system  100  comprises a rotating fan apparatus  110  and a cooling assembly  120 , see  FIG. 2 . Both the fan apparatus  110  and the cooling assembly  120  are mounted to a rear portion  20 A of the vehicle main frame  20 , see  FIGS. 1 ,  2 ,  4  and  6 . 
     The fan apparatus  110  comprises a rotatable fan  112  and a motor  114 . The motor  114  comprises a hydraulic motor in the illustrated embodiment, but may comprise an electric motor. During normal operation of the vehicle  10 , the motor  114  effects rotation of the fan  112  in a first direction to pull air from inside the engine compartment  22 , see direction arrow A in  FIG. 6 , through the cooling assembly  120 , then through an opening O in the rear V R  of the vehicle  10 , see  FIG. 5 . As the air passes through the cooling assembly  120 , it removes energy in the form of heat from a coolant fluid that circulates through the engine  23  and the cooling assembly  120 . The motor speed may vary with a temperature of the coolant fluid. Preferably, the fan motor  114  is capable of reversing direction, such as when the vehicle  10  is first started or at any desired time, to effect rotation of the fan  112  in a second direction, opposite to the first direction, to force air through a filter element  130  forming part of the cooling assembly  120 , to force debris off of the filter element  130 . 
     In the illustrated embodiment, the cooling assembly  120  comprises a heat exchanger  140 , e.g., a radiator, and a filter structure  150 , see  FIG. 2 . Appropriate hoses  220 , see  FIG. 1 , extend between the engine  23  and the heat exchanger  140  to allow the coolant fluid to flow between the engine  23  and the cooling assembly  120 . The heat exchanger  140  transfers energy in the form of heat from the coolant fluid circulating through the engine  23  to air forced through the heat exchanger  140  by the fan apparatus  110 . 
     In the illustrated embodiment, the filter structure  150  comprises a support frame  152 , the filter element  130 , and a filter element seal structure  154  (also referred to herein as a third seal structure), see  FIGS. 2-4 . The filter element seal structure  154  is positioned about an outer periphery of the filter element  130  and held thereon via a friction fit or a conventional adhesive. The filter element seal structure  154  may be formed from closed cell foam. The support frame  152  comprises first and second side sections  152 A and  152 B and upper and lower sections  152 C and  152 D, see  FIG. 3 . The first and second side sections  152 A,  152 B and the upper and lower sections  152 C,  152 D define a passage  152 E through the support frame  152 . The lower section  152 D comprises a first wall  153 A that extends upward from about 10 mm to about 15 mm from a lower wall  1152 D of the lower section  152 D, see  FIG. 8 . The first wall  153 A further extends along generally the entire length of the lower section  152 D. The lower section  152 D further comprises a second wall  153 B that extends at an angle away from the first wall  153 A. The first and second walls  153 A and  153 B define a recess or pocket  153 C for receiving a lower portion  130 A of the filter element  130 , see  FIGS. 6 and 8 . The seal structure  154  seals the outer periphery of the filter element  130  to the support frame  152  so as to prevent air, dirt and debris from passing through an interface between the filter element  130  and the support frame  152  and bypassing the filter element  130 . The filter element  130  may comprise a metal or polymeric mesh screen, a filter media or a combination of a mesh screen and a filter media. 
     A handle structure  132  is bolted, riveted or otherwise coupled to an upper portion  130 B of the filter element  130 , see  FIGS. 6 ,  7  and  11 . In the illustrated embodiment, the handle structure  132  does not move or pivot relative to the filter element upper portion  130 B. The handle structure  132  comprises a generally L-shaped gripping portion  132 A and a pin  132 B extending between extensions  132 C and  132 D of the gripping portion  132 A, see  FIGS. 7 and 11 . A U-shaped spring clip  253 C is coupled to the upper section  152 C of the support frame  152 , see  FIG. 11 , for receiving the pin  132 B so as to secure the filter element  130  to the support frame  152 . To attach the filter element  130  to the support frame  152 , the filter element lower portion  130 A is inserted into the recess  153 C defined in the lower section  152 D of the support frame  152  while the pin  132 B of the handle structure  132  is aligned with and inserted into the U-shaped spring clip  253 C. Once the filter element lower portion  130 A is fully seated in the recess  153 C and the handle structure pin  132 B is received in the spring clip  253 C on the support frame upper section  152 C, the filter element  130  is attached to the support frame  152 . An operator can remove the filter element  130  from the support frame  152  by pulling up on the gripping portion  132 A so as to disengage the pin  132 B from the spring clip  253 C. 
     In the illustrated embodiment, the support frame  152  is shaped/configured so that when the filter element  130  is attached to the support frame  152 , the filter element  130  is positioned at an angle to vertical, e.g., from about 5 degrees to about 10 degrees and preferably about 7 degrees to vertical. More specifically, the upper portion  130 B of the filter element  130  is spaced a first distance D 1  away from the heat exchanger  140  and the lower portion  130 A of the filter element  130  is spaced a second distance D 2  away from the heat exchanger  140 , with the first distance being greater than the second distance, see  FIG. 6 . Hence, the filter element  130  is angled downward such that an outer face  130 C of the filter element  130  is facing downward towards a surface S over which the truck  10  travels, see  FIGS. 1 and 6 . Consequently, when the fan motor  114  reverses its direction to effect rotation of the fan  112  in the second direction, air from outside of the truck  10  is force through the cooling assembly  120 , see direction arrow B in  FIGS. 1 and 6 , to force debris off of the filter element  130 . Because the filter element  130  is angled downward, it is believed that gravity provides some assistance to the air in forcing debris from the filter element  130  and also causes the debris to fall down onto the surface S. Further, the support frame  152 , due to its configuration, causes air passing through the filter element  130  and debris forced off the filter element  130  to be directed downward towards the surface S. 
     The cooling assembly  120  further comprises a first seal structure  160 , a second seal structure  170  and a fan shroud  180 , see  FIG. 3 . The first seal structure  160  may comprise a plurality of first seal strips  160 A formed from closed cell foam. The seal strips  160 A are positioned between peripheral surfaces  152 A and  140 A of the support frame  152  and the heat exchanger  140 , respectively, to seal an interface between the support frame  152  and the heat exchanger  140 , see  FIGS. 2 ,  9  and  10 . The seal strips  160 A may be frictionally held between the support frame  152  and the heat exchanger  140  or adhesively secured to one or both of the support frame  152  and the heat exchanger  140 . 
     The second seal structure  170  may comprise a seal strip  170 A formed from closed cell foam. The seal strip  170 A is positioned between peripheral surfaces  140 B and  180 A of the heat exchanger  140  and the fan shroud  180 , respectively, to seal an interface between the heat exchanger  140  and the fan shroud  180 , see  FIGS. 9 and 10 . The seal strip  170 A may be frictionally held between the heat exchanger  140  and the fan shroud  180  or adhesively secured to one or both of the heat exchanger  140  and the fan shroud  180 . 
     The cooling assembly  120  also comprises connecting structure  200  to couple together the filter structure  150 , the first and second seal structures  160  and  170 , the heat exchanger  140  and the fan shroud  180 , see  FIGS. 3 ,  6  and  9 . In the illustrated embodiment, the connecting structure  200  comprises first and second upper spacers  200 A, first and second lower spacers  200 B and corresponding bolts  202  that pass through bores in the spacers  200 A and  200 B, see  FIGS. 3 ,  6  and  9 . The bolts  202  also extend through corresponding bores or recesses  152 F and  180 A in the support frame  152  and the fan shroud  180 , see  FIG. 3 . The spacers  200 A and  200 B are located between the support frame  152  and the fan shroud  180 , see  FIG. 3 . Corresponding nuts  204 A engage with the bolts  202  such that the connecting structure  200  secures the filter structure  150 , the first and second seal structures  160  and  170 , the heat exchanger  140  and the fan shroud  180  together as a single assembly. The cooling assembly  120  may be assembled outside of the vehicle main frame  20  and, once assembled, then installed into the vehicle main frame  20 . 
     The cooling assembly  120  may still further comprise a main frame seal structure  190 , see  FIGS. 2 and 3 , located between the fan shroud  180  and the vehicle main frame  20 . The main frame seal structure  190  may comprise a plurality of seal strips  190 A formed from ethylene propylene diene M-class rubber (EPDM) bulb edge seal, which is commercially available from PPR Industries. The seal strips  190 A are positioned between the outer periphery  180 A of the fan shroud  180  and an engagement surface (not shown) on the vehicle main frame  20  to seal an interface between the fan shroud  180  and the vehicle main frame engagement surface. The seal strips  190 A may be frictionally held between the fan shroud  180  and the vehicle main frame engagement surface or adhesively secured to one or both of the fan shroud  180  and the vehicle main frame engagement surface. The seal strips  190 A prevent air being expelled by the fan  112  from passing back into the engine compartment  22  between the fan shroud  180  and the vehicle main frame  20  and then, once again, through the heat exchanger  140 . Heated air re-circulated through the heat exchanger  140  reduces the efficiency of the heat exchanger  140 . 
     Having described the invention in detail and by reference to preferred embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.