Abstract:
This is a system and apparatus for precisely mounting a ring shroud to a motor vehicle cooling system and engine. A cooling fan subassembly is mounted to an engine and ring shroud subassembly containing fan braces that are mounted to the engine via mounting brackets. A mounting gap tool is inserted through apertures in the ring shroud to prescribe the radial and axial clearance between the ring shroud and the cooling fan subassembly. Once the ring shroud and cooling fan assembly are aligned to predetermined specifications for clearance, the installer secures all the fasteners in the mounting brackets and retrieves any or all the mounting gap tools.

Description:
BACKGROUND 
     Heavy transportation machinery including motor vehicles such as light-duty, medium-duty, and heavy-duty trucks for personal and commercial use, and off-highway equipment and vehicles are typically constructed and assembled via separate subassemblies. One such subassembly is the motor cooling system which includes a front or side mounted fan for certain operation requirements. An additional subassembly is the radiator and cooling assembly. Both of these subassemblies are intended to be mated such that the fan facilitates in drawing air through the radiator assembly for facilitating in the cooling of the engine. There are a variety of fans used in these types of applications such as axial-flow fans, radial-flow fans, mixed-flow fans and high-efficiency hybrid-flow fans. Additionally, in the radiator or cooling assembly, it is common to include a ring shroud or cowling that surrounds the fan and which is intended for increasing the fan efficiency and reducing the sound of the operation of the fan. 
     An integral feature of the manufacturing of these subassemblies including the ring shroud is the tolerances which must be observed in the manufacturing. In order to maximize the performance of the fan, sufficient efforts should be made to mount the ring shroud very precisely around the fan, that is, there must be consistent clearance or a gap around and in between the entire circumference of the fan outer ring and the ring shroud. Such tolerances must be carefully controlled in order to preserve the performance and reliability of the machine. Not only does the ring shroud facilitate in improving the efficiency of the fan, but the gap between the ring shroud and fan outer ring is necessary to avoid crash conditions between them. Since the fan subassembly is connected to the engine, movement of the engine results in relative movement of the fan subassembly relative to the ring shroud. Consequently, interference may exist which may damage the fan outer ring and the fan vanes, thus the importance of sufficient and consistent gap between the ring shroud and the fan outer ring. 
     Accordingly, there is a need to ensure that the fan subassembly is mounted accurately and precisely within the ring shroud during manufacturing utilizing a simple system which facilitates the ease of assembly for an installer during the manufacturing process and also requires limited parts to limit costs. The described embodiment is directed to overcoming problems triggered by the variation present in most large scale manufactured parts and associated with mounting the ring shroud with respect to the fan subassembly. 
     SUMMARY 
     Disclosed herein are embodiments of a cooling fan and gap tool. In one embodiment, a fan assembly and gap tool for motor vehicle cooling system comprises an engine, a fan motor, a cooling fan, at least three mounting brackets, a ring shroud, and at least three fan braces. The fan motor is mounted to the engine. The cooling fan is mounted to the fan motor. Each of the at least three fan braces is affixed to the ring shroud. Each of the at least three mounting brackets has one end and an opposite end. Each of the at least three mounting brackets is mounted to the engine at the one end and is loosely mounted to one of the at least three fan braces at the opposite end. A plurality of gap tools align the ring shroud to the cooling fan before securing the at least three mounting brackets to the at least three fan braces. 
     Another embodiment provides a gap tool for mounting a ring shroud to a cooling fan assembly in a motor vehicle. In this embodiment, the gap tool comprises a head, an elongated cylinder having one end and an opposite end, a shoulder stop and at least one resilient arm. The head is connected to the one end of the elongated cylinder. The elongated cylinder has a beveled finish at the opposite end. The shoulder stop is attached to the elongated cylinder in a planar configuration with the head. The at least one resilient arm is attached to the elongated cylinder and gradually and continuously diverges outwardly from the opposite end of the elongated cylinder. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a side elevational view of gap tool disclosed herein; 
         FIG. 1B  is a side elevational view rotated 90 degrees from  FIG. 1A ; 
         FIG. 1C  is a sectional view taken along line A-A of  FIG. 1A ; 
         FIG. 1D  is an end view taken along line B-B of  FIG. 1A ; 
         FIG. 1E  is a perspective view of the gap tool of  FIG. 1A   
         FIG. 2  shows an exploded view of a high efficiency hybrid fan and 15 liter engine. 
         FIG. 3  shows an exploded view of a high efficiency hybrid fan and 15 liter engine (rear). 
         FIG. 4  shows an exploded view of a 15 Liter engine with fan motor. 
         FIG. 5  shows a perspective view of a 15 Liter engine with fan motor. 
         FIG. 6  shows an exploded view of a high efficiency hybrid fan, fan hub nuts, fan motor and 15 L engine. 
         FIG. 7  shows a perspective view of a high efficiency hybrid fan and 15 L engine. 
         FIG. 8  shows an exploded view of a high efficiency hybrid fan, 15 L engine and mounting brackets. 
         FIG. 9  shows a perspective view of a high efficiency hybrid fan, 15 L engine and mounting brackets. 
         FIG. 10  shows an exploded view of the ring shroud, high efficiency hybrid fan, 15 L engine and mounting brackets. 
         FIG. 11  shows a perspective view of partially assembled ring shroud, high efficiency hybrid fan, 15 L engine and mounting brackets. 
         FIG. 12  shows a perspective view of the gap tool. 
         FIG. 13  shows an exploded view of gap tool and ring shroud with keyhole. 
         FIG. 14  shows a cross-sectional view of the gap tool, ring shroud, fan vane and fan rubber seal. 
         FIG. 15  shows a perspective view of partially assembled ring shroud, high efficiency hybrid fan, 15 L engine and mounting brackets and gap tool. 
         FIG. 16  shows a close up view of inserted gap tool in ring shroud. 
         FIG. 17  shows a perspective view of the partially assembled ring shroud, high efficiency hybrid fan, 15 L engine, mounting brackets, gap tools and clamping devices. 
         FIG. 18  shows a perspective view of an assembled high efficiency hybrid fan and 15 liter engine. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of a fan assembly and a gap tool are disclosed. One embodiment comprises a system for mounting a ring shroud to a motor vehicle cooling system and engine. This system comprises of an engine that supports a fan subassembly having a fan motor, a cooling fan that is mounted to the fan motor which is propelled by the engine. The cooling fan member has a fan hub and a plurality of fan vanes extending outwardly from the fan hub. The fan vanes sit in between a fan circumferential ring and a fan outer ring. The fan circumferential ring is attached to the fan vanes and it surrounds the fan hub, the fan circumferential ring member has a disc shape extending radially. The fan outer ring has an annular shape and is attached to the tips of the fan vanes. The fan subassembly is partially covered by a ring shroud mounted in front of the fan outer ring. The ring shroud comprises of an annular shaped ring shroud base, a fan rubber seal, and mounting hardware such as ring inlets or fan braces. The ring shroud base has perforations to allow the insertion of a mounting or gap tool during assembly or subassembly. 
     In another embodiment, the assembly of the ring shroud to the fan subassembly involves the engagement of several mounting brackets between the engine and the ring shroud and the use of a plurality of gap tools. After the cooling fan subassembly has been installed, the method of assembly of the ring shroud to the cooling fan assembly entails installing mounting brackets to the engine, followed by tightening the fasteners in the mounting brackets at the engine end but leaving the fasteners loose at the opposite end. The ring shroud mounting hardware or braces may have oversized holes that would allow for any necessary adjustments during the ring shroud placement. The ring shroud is mounted against the free end of mounting brackets that were previously mounted to the engine at the opposite end. While the fasteners in the ring shroud end are still loose, the gap tools are inserted through apertures in the pre-perforated ring shroud base. 
     In some embodiments, the gap tool facilitates the aligning of the ring shroud against the fan outer ring by providing static conditions and defining precisely the radial and axial gap between the interior of the ring shroud base and the exterior of the fan outer ring. Several gap tools may be inserted through the pre-perforated ring shroud base. The head of the gap tool acts a stopper restricting how far the gap tool will penetrate once inserted through the ring shroud base aperture. The shoulder stop of the gap tool defines the axial gap between the interior of the ring shroud base and the exterior fan outer ring. The elongated cylinder body of the gap tool defines the radial gap between the interior of the ring shroud base and the exterior fan outer ring. 
     In an embodiment of the gap tool, at least two resilient arms are attached to the elongated cylinder body and extend outwardly from the beveled end tip. The resilient arms will be urged together during the gap tool positioning through the ring shroud aperture. Once completely inserted, the resilient arms return to a deployed configuration securing the gap tool in place while engaged between the ring shroud base and the fan outer ring. Once sufficient gap tools have been inserted, at least two clamping devices may be positioned temporarily at opposite ends to grip together the fan subassembly, including the ring shroud. At this point, the remaining loose fasteners within the mounting brackets engaged between the engine and the ring shroud end are tightened to secure the cooling fan assembly together. Once the fasteners are tightened, the ring shroud and fan assembly has been securely mounted. The clamping devices and the gap tools can then be removed. Each gap tool can be removed by urging the resilient arms together to reverse the previously deployed configuration into an un-deployed configuration. The un-deployed configuration allows the inserted section of the gap tool that passed through the ring shroud aperture to be removed and disengaged from the ring shroud and fan assembly. 
       FIG. 1A  to  FIG. 1E  and  FIG. 12  show an embodiment of the gap tool  200  for mounting a ring shroud  320  onto to a cooling fan  300  assembly.  FIG. 1A  shows a side view of the gap tool  200 .  FIG. 1A  shows a tool shaped similar to a commercially available key having attached one resilient arm  250  coming out the side of its main body or elongated cylinder  240 .  FIG. 1A  shows in one end of the gap tool  200 , a head  220  in the shape of a key bow or a crest but it can be any shape as long as it is larger than the keyhole or aperture  210  in the perforated the ring shroud  320  and is large enough for a person&#39;s hand or machine to grip. Dimensionally, the head  220  has about twice the height (y-plane) when compared to its width (x-plane). The head  220 , which is left protruding out of the ring shroud  320  when the gap tool  200  is in use, has a slope of about thirty-four degrees that rises (x-y plane) from the elongated cylinder  240  body on its upper side. 
     Attached to the head  220  in  FIG. 1A  is an elongated cylinder  240  that makes the main part of the gap tool  200  body and defines the radial gap  290  between the interior of the ring shroud  320  and the exterior of the fan outer ring  340 . According to  FIGS. 1A and 1B  the length of the elongated cylinder  240  from the head  220  to the beveled tip  260  is about twice as long as the distance between the head  220  and the end of the shoulder stop  230  (x-plane).  FIG. 1A  shows at the end opposite to the head  220  a beveled tip  260  cut in about a twenty-two degree angle and rising from the x-plane. 
       FIG. 1A  shows the shoulder stop  230 . The shoulder stop  230  saliently comes out of the elongated cylinder  240  in the x-y plane. The shoulder stop  230  may be in a rectangle shape, its dimension defines the axial gap  280  between the interior of the ring shroud  320  and the exterior of the fan outer ring  340 , and it is about half as long as the longest span of the elongated cylinder  240  starting from the end of the head  220  to the beveled tip  260 . 
       FIG. 1B  and  FIG. 1C  show the two resilient arms  250  in a z-plane and being attached and parallel to the elongated cylinder  240  body. The two resilient arms  250  gradually and continuously diverge outwardly at about a three degree angle from the beveled tip end  260  of the elongated cylinder  240 . The resilient arms  250  span to a length approximately half of the length of the gap tool  200  including the head  220  and the elongated cylinder  240  body. The resilient arms  250  are sufficiently resilient so that the resilient arms  250  can be urged or squeezed together into an un-deployed or closed configuration when pressure or force is applied. The resilient arms  250  should be capable of springing back to an open or deployed configuration once the pressure or force is removed. 
       FIG. 1D  is an end view taken along line B-B of  FIG. 1A .  FIG. 1D  shows the depth (z-plane) of the shoulder stop  230  being about half the size of the depth of the head  220 .  FIG. 1D , additionally the outward span of the resilient arms  250  are shown as slightly wider than the diameter of the elongated cylinder  240  body. 
       FIG. 1E  is a perspective view of the gap tool of  FIG. 1A  having a head  220 , a shoulder stop  230 , a resilient arm  250  and an elongated cylinder  240  body with a beveled tip. 
     The gap tool  200  can be made of any thermoset polymer material, thermoplastic polymer material, metal, or wood among other materials. Depending on the material, the gap tool  200  can be manufactured by injection molding, extrusion, casting, or spin casting among other methods. 
       FIGS. 2 to 18  shows the gap tool  200  for mounting a high efficiency hybrid fan to a 15 L engine but the embodiment and utility of the gap tool is not limited to high efficiency hybrid fan systems or to 15 L engines as it could be useful on any type of cooling system for a motor vehicle engine that contains a shroud or cowling part mounted to a fan assembly. 
     The cooling fan  300  system in the embodiment shown in  FIGS. 2-3  and  FIGS. 6-11  has a fan hub  360 , a fan circumferential ring  330  surrounding the fan hub  360 , a plurality of fan vanes  310  that are positioned around the fan hub  360  and fan outer ring  340  connected to the ends of the fan vanes  310  members. The use of fan vanes  310  and rotating ring elements such as the fan circumferential ring  330  and the fan outer ring  340  to form a cooling fan  300  subassembly is well known in the art, and these fan subassemblies are commonly referred to as ring fans. 
     Although the embodiments of the fan circumferential ring  330  and the fan outer ring  340  shown in  FIGS. 2-3  are solid, it is also possible that either one be discontinuous with gaps between the vanes or have openings in the ring itself, or that the ring member (or discontinuous portions thereof) can be positioned radially inwardly slightly from the ends of the fan vanes  310 . 
       FIG. 2  and  FIGS. 6-10  show a fan outer ring  340  that is intricately formed with the cooling fan  300  assembly and thus fixedly attached to the tips of the fan vanes  310 . In accordance with an embodiment of the present invention, the fan outer ring  340  can also have a concave shape. 
       FIGS. 2-3 ,  FIGS. 10-11 , and  FIGS. 15-17  show a ring shroud  320  having an annular shape. The ring shroud  320  has incorporated along its circumference four fan braces  350  that serve as its mounting hardware. The ring shroud  320  is to be positioned circumferentially around, or substantially circumferentially around, all or a principal portion of the rotating fan outer ring  340 .  FIGS. 2-3 ,  FIGS. 10-11 ,  FIGS. 13-18  show a fan rubber seal  370  surrounding the ring shroud  320 . Although in the present embodiment the ring shroud  320  has four fan braces  350 , it is possible to have less or more than four fan braces  350  for mounting a ring shroud  320  to a cooling system  300  assembly. 
     The method of mounting the ring shroud  320  to the cooling fan  300  assembly using the described embodiment of the gap tool  200  begins by mounting the fan motor  110  to the engine  100  as shown in  FIG. 4 . Once the fan motor  110  is installed, as shown in  FIG. 5 , the shoulder portions of the shoulder nuts  400  are added.  FIG. 6  shows a pre-assembled cooling fan  300  as it is being installed against the fan motor  110  and it is bolted in place with the use of the nut portion of the shoulder nuts  400 . 
       FIG. 7  shows the cooling fan  300  installed on the engine  100 .  FIG. 8  shows mounting brackets  410  of a variety of shapes and sizes all having T-shape ends. In addition,  FIG. 8  shows the cooling fan  300  and the engine  100  subassembly.  FIG. 9  shows the mounting brackets  410  attached to different parts of the engine  100  at one end and not attached to anything at the opposite end with some fasteners  415  tightened and other fasteners  415  loose in preparation for subsequent subassembly steps. 
       FIG. 10  shows the engine  100 , the cooling fan  300 , the mounting brackets  410  and the ring shroud  320  with four fan braces  350 , and a fan rubber seal  370  surrounding the ring shroud  320 . Each fan brace  350  in  FIGS. 2-3  and  FIGS. 10-11  have a face plate  345  end with holes  355 . The fan brace holes  355  may be oversized to allow for adjustments during assembly and are intended to be attached to mounting brackets  410  with the help of fasteners  415 .  FIG. 11  shows the ring shroud  320  subassembly mounted to the mounting brackets  410 , the fasteners  415  of the mounting brackets  410  are tightened on the engine  100  side only. 
       FIG. 13  shows that while the mounting brackets  410  are fastened in the engine  100  end and loose in the ring shroud  320  end, a plurality of gap tools  200  are inserted through perforated holes  210  in the ring shroud  320 .  FIG. 14  shows a cross-sectional view of the gap tool  200  being used to create a static condition during assembly and align the interior of the ring shroud  320  to the exterior fan outer ring  340 . The shoulder stop  230  of the gap tool  200  sets the axial distance or clearance  280  between the interior of the ring shroud  320  and the exterior of the fan outer ring  340 . The elongated cylinder  240  body of the gap tool  200  serves to set the radial distance or clearance  290  between the interior of the ring shroud  320  and the exterior of the fan outer ring  340 . 
       FIG. 15  shows the engine  100 , the cooling fan  300  assembly with four engaged gap tools  200  (only the head  220  portion and the outside portion of the resilient arms  250  can be seen) about ninety degrees from each other.  FIG. 16  shows a segment of the ring shroud  320 , the fan rubber seal  370 , the fan vanes  310 , the head  220  and the tip of two resilient arms  250  of the gap tool  200 . In order to release the gap tool  200  from the ring shroud  320  and cooling fan  300  assembly, the resilient arms  250  may be squeezed together by manually exerting pressure on both sides inward towards the head  220 . 
       FIG. 17  shows the engine  100 , the cooling fan  300  assembly with four engaged gap tools  200  (only the head  220  portion and the outside portion of the resilient arms  250  can be seen) about ninety degrees from each other.  FIG. 17  shows two commercially available clamping devices  420  clasping together the ring shroud  320 , the fan rubber seal  370 , and the cooling fan  300  including the fan circumferential ring  330  in the rear of the cooling fan  300  assembly. Although  FIG. 17  suggests the use of only two clamping devices, the described method of assembly can use more than two clamping devices  420 . 
     Once the gap tool  200  has facilitated the positioning of the ring shroud  320  over the cooling fan  300  assembly then the assembly operator (not shown) either manually or through automation will tighten the remaining loose fasteners  415  whereby securing the ring shroud  320  and cooling fan  300  assembly. After the fasteners  415  are tightened on all mounting brackets  410 , the gap tools  200  may be removed manually or through automation means by urging the resilient arms  250  together with enough force to allow the gap tool  200  to once again fit through the ring shroud aperture  210  and be completely retrieved. 
       FIG. 18  shows the finished ring shroud  320  and cooling fan  300  assembly mounted on an engine  100 . 
     Although the assembly method described utilizes mounting brackets with fasteners, the same outcome can be achieved with alternative mounting means while using the embodiment of the mounting gap tool  200  described. In place of mounting brackets with fasteners, the operator may use adhesive methods such as an epoxy adhesive for securing a ring shroud to a cooling assembly after the gap tools have been inserted to set the clearance between the subassembly components.