Patent Publication Number: US-2010126924-A1

Title: Anti-rotation of shell relative to nutplate

Description:
FIELD 
     This disclosure relates generally to fluid filtration, and more particularly to a filter assembly that includes a shell and a nutplate. 
     BACKGROUND 
     A known type of filter assembly used in a vehicle engine such as a diesel engine includes a filter housing or shell, a filter cartridge that is disposed within the filter housing and a nutplate for closing an open end of the filter housing. 
     In these types of filter assemblies, the nutplate is usually provided with both an upper groove and a lower groove on an outer edge. The lower groove is configured to seat an O-ring, while the upper groove circumscribes the upper portion of the filter housing. 
     A roll forming operation is usually performed to deform the filter housing into the upper groove of the nutplate. This roll forming operation is typically followed by a secondary operation such as a staking operation to stake the housing into the groove to prevent the filter housing from slipping or rotating relative to the nutplate during filter installation or removal. 
     SUMMARY 
     A filter assembly that includes a nutplate having pre-formed anti-rotation features that prevent rotation of the shell relative to the nutplate and a method for producing the disclosed filter assembly are described. The disclosed method radially deforms a flange of the housing to the shape of the pre-formed anti-rotation features, and does not utilize a secondary operation such as a staking operation to stake selected edge portions. The filter assembly described herein can be used in automotive/diesel truck engines for filtering various engine fluids including but not limited to fuels such as diesel fuel, oils, and hydraulic fluids. 
     In one embodiment, the disclosed filter assembly includes a housing, which is also referred to as a shell, having a side wall, a base portion, an open end and an interior space and a nutplate, which is also referred to as a retainer, having fluid inlet openings that extend through the nutplate and direct fluid to be filtered into the interior space, a hub having an opening through which filtered fluid exits the filter assembly, and a sidewall. The sidewall of the nutplate is provided with a groove that includes a plurality of pre-formed anti-rotation features. In one example, each of the preformed anti-rotation features is a faceted region and the groove further includes a plurality of contour regions, the contour regions and the faceted regions alternating with each other around the groove. The housing further includes a portion proximate to the open end that is disposed within the first groove and that conforms to the plurality of pre-formed anti-rotation features. 
     In one embodiment of the method of forming the disclosed filter assembly, a seamer machine is utilized for performing a seaming operation. In one example, a profile roll is advanced into a flange of the housing that is disposed within the groove on the nutplate using a servo actuator within the seamer machine. The seaming operation is then performed so that the profile roll engages the flange of the shell, and the servo actuator follows the shape the groove of the nutplate such that the flange is radially deformed to conform the flange to the shape of the groove including the pre-formed anti-rotation features. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a cross-sectional side view of the assembled filter assembly. 
         FIG. 1B  is an enlarged view of the dotted outline area in  FIG. 1A . 
         FIG. 2A  is a perspective view of the nutplate of the filter assembly. 
         FIG. 2B  is an enlarged view of the dotted outline area in  FIG. 2A . 
         FIG. 3A  is a cross-sectional side view of the nutplate of the filter assembly. 
         FIG. 3B  is a cross-sectional top plan view of the nutplate of  FIG. 3A . 
         FIG. 4  is an enlarged view of the dotted outline area in  FIG. 3B . 
         FIG. 5A  is a partial cross-sectional side view of the nutplate shown in  FIG. 3B . 
         FIG. 5B  is another partial cross-sectional side view of the nutplate shown in  FIG. 3B . 
         FIG. 5C  is yet another partial cross-sectional side view of the nutplate shown in  FIG. 3B   
         FIG. 5D  is a partial cross-sectional side view of the shell and the pre-formed anti-rotation feature. 
         FIG. 6  illustrates one embodiment of the disclosed method. 
         FIG. 7A  illustrates a partial cross-sectional side view of the shell and nutplate before deformation. 
         FIG. 7B  illustrates another partial cross-sectional side view of the shell and nutplate before deformation. 
     
    
    
     DETAILED DESCRIPTION 
     A filter assembly having anti-rotation features that prevent rotation of a shell relative to a nutplate and a method of forming the disclosed filter assembly are described. The concepts described herein will be described with respect to a fuel filter assembly in a diesel engine. However, in appropriate circumstances, it is to be realized that the concepts can be applied to other types of filter assemblies as well. In addition, the fluid used can include any vehicle fluids including, but not limited to, oil, fuel such as diesel fuel, hydraulic fluid, etc. 
     Referring to  FIG. 1A , a filter assembly  10  includes a housing  13 , a nutplate  15  and a filter element  19 . The housing  13  is hollow and cylindrical in shape. The housing  13  has a closed end  13   a,  an open end  13   b,  a sidewall  22  and an interior space  25 .  FIG. 1A  shows the housing  13  as being cylindrical, but in appropriate circumstance, the housing  13  could have different shapes. In addition, the material of the housing  13  can be formed of any material that is suitable for forming a shell on a filter assembly, including, but not limited to, aluminum, steel, etc. 
     A filter element  19  includes a filter media  30 , a bottom end plate  33  and a top end plate  37 . The filter media  50  can be any filter media that is suitable for filtering fluid with which the disclosed filter assembly is to be used. 
     The filter media  30  is generally cylindrical and surrounds a center tube  35  which functions to retain the geometrical shape of the filter media  30 . During use, an unfiltered fluid enters a space  25   a  defined between the inner surface  13 ′ of the housing  13  and the outer region  30 ′ of the filter media  30 , and flows through the filter media  30  toward the center tube  35  so as to filter the fluid. 
     The bottom endplate  33  is secured to a bottom end  30   a  of the filter media  30  and is substantially circular. The bottom endplate  33  is provided to prevent filtered fluid from passing to a bottom space  39  of the housing  13  from the center tube  35 . 
     The top endplate  37  is secured to a top end  30   b  of the filter media  30 . The top end plate  37  includes a base plate  56  that is substantially circular and a central opening  62 . A sleeve  64  extends upwardly from the edge of the central opening  62  towards the open end  13   b  of the housing  13  so as to define a flow passageway  69 . During use, fluid filtered by the filter media  30  flows through the central opening  62 , and into the flow passageway  69  and out the sleeve  64  to an engine. 
     The material of the bottom endplate  33  and the top endplate  37  can be any material that is suitable for use with the disclosed filter assembly, including, but not limited to, metal, composite, plastic, etc. In addition, the filter media  30  can be secured to the bottom endplate and the top endplate  37  by any means, including, but not limited to adhesives, etc. 
     The open end  13   b  of the housing  13  receives the nutplate  15 , which may also be referred to as a retainer. Referring to  FIG. 2A , the nutplate  15  includes a hub  50  that receives the sleeve  64  of the top end plate  37  such that the nutplate  15  can be removably mounted to the filter element  19 . The nutplate  15  further includes a plurality of ribs  52  between the hub  50  and a sidewall  70  of the nutplate  15 . The plurality of ribs  52  define fluid inlet openings  55  that extend through the nutplate  15  and direct fluid to be filtered into the interior space  25 . Any number and shapes suitable for use with the disclosed assembly can be used for the ribs  52  and fluid inlet openings  55 . A gasket groove  65  is formed in the top surface of the nutplate  15 , and a gasket  31  (see  FIG. 1A ) seats within the groove  65  and functions to seal, for example, a surface surrounding a spud of a diesel engine. 
     The nutplate  15  can be made of any material suitable for use with the disclosed assembly, including, but not limited to, aluminum, steel, etc. 
     Referring to  FIGS. 1B ,  2 A and  3 A, the sidewall  70  of the nutplate  15  includes an upper groove  72  and a lower groove  74  formed therein. The lower groove  74  seats a seal  79  that provides a seal between the nutplate  15  and the housing  13 . The shape of the groove  74  can be any shape that is suitable for seating the seal  79 . 
       FIG. 3B  shows a detailed section taken along axis  3 B- 3 B of  FIG. 3A . As shown in  FIG. 3B , the outline of a rear wall  79  of the upper groove  72  is substantially circular while the outline of a portion  70   a  of the sidewall  70  between the grooves  72 , 74  circumscribes the outline of the rear wall  79 , the term “rear” herein being defined as the bottom of the depth of the upper groove  72 . The upper groove  72  includes a plurality of contour regions  84  and a plurality of pre-formed anti-rotation features  82 , the term “pre-formed” herein being defined as formed before the step of deforming the shell into the groove of the nutplate. In one example, the rear wall  79  includes a rear wall region  79   a  and a rear wall region  79   b.  As shown in  FIG. 3B , each of the contour regions  84  include the rear wall region  79   a,  the rear wall region  79   a  being convex in top plan view, while each of the anti-rotation features  82  is a faceted region such that each of the anti-rotation features  82  includes the rear wall region  79   b,  the rear wall region  79   b  being substantially linear in top plan view. 
     Referring to  FIG. 3A , the left-hand portion of the drawing illustrates the cross-sectional side view of one of the contour regions  84  of the upper groove  72 . The upper groove  72  within one of the contour regions  84  has a substantially round C-shaped cross-section. The upper groove  72  has a groove depth of z, the term “groove depth” herein being defined as the orthogonal distance from the outer surface of the portion  70   a  of the sidewall  70  and the rear wall  79  of the groove  72 . In one aspect, the groove depth and the width of the upper groove  72  are dependent on the thickness of the housing  13 , the thickness of the housing  13  being proportional to the filter application and engine pressures, where higher pressure requirements equal thicker shell wall, which equals larger minimum bend radius. Referring back to  FIG. 1B , in the assembled form, a portion  13   c  proximate to the open end  13   b  of the housing  13  has a C-shaped groove  13   d  that conforms to the C-shaped upper groove  72  of the nutplate  15  within the contour regions  84 . 
     Referring now to the right-hand portion of the drawing in  FIG. 3A , the cross-sectional side view of one of the faceted regions  82  is illustrated in dotted lines. The upper groove  72  within the faceted regions  82  has a substantially round C-shaped cross-section similar to the C-shaped cross-section within the contour regions  84 , but with a deeper groove depth, that is, a groove depth that is greater than z. 
       FIG. 4  shows an enlarged view of the dotted outline region of  FIG. 3B  while  FIGS. 5A ,  5 B and  5 C show detailed cross sections taken along axes  5 A- 5 A,  5 B- 5 B and  5 C- 5 C, respectively.  FIGS. 4 and 5A  show the groove depth within the contour region as being z. Referring to  FIGS. 4 and 5C , in the section along the axis  5 C- 5 C, which is orthogonal to and positioned at the mid-point of the outline of the rear wall region  79   b,  the distance between the mid-point of the outline of the rear wall region  79   b  and the outline of a hypothetical rear wall region  79   a′  (shown in dashed lines in  FIG. 4 ) is defined by x, the outline of the hypothetical rear wall region  79   a ′ representing the outline of the rear wall region that would be present if the faceted regions  82  were the contour regions  84 . The orthogonal distance between the outline of the hypothetical rear wall region  79   a ′ and the outline of the portion  70   a  of the sidewall  70  is z. Thus, the groove depth of the upper groove  72  along the axis  5 C- 5 C is x+z. While various configurations of the contour regions  84  and faceted regions  82  are possible, an x value of about 0.170 inch, an x+z value of about 0.217 inch and the rear wall region  79   b  having a length of about 0.844 inch have produced satisfactory results. 
     The groove depth decreases away from the axis  5 C- 5 C as illustrated by  FIGS. 4 and 5B . The axis  5 B- 5 B is a representative of an axis that is removed from the axis  5 C- 5 C and is orthogonal to the outline of the hypothetical rear wall region  79   a ′. As shown in  FIG. 5B , in the section along the axis  5 B- 5 B, the distance between the outline of the rear wall region  79   b  and the outline of the hypothetical rear wall region  79   a ′ is defined by y i , which is smaller than x. In this instance, the groove depth of the upper groove  72  along the axis  5 B- 5 B is y i +z, where y i  approaches zero as the axis  5 B- 5 B is further removed from the axis  5 C- 5 C. 
     Referring to  FIG. 5D , in the assembled form, a portion  13   e  proximate to the open end  13   b  of the housing  13  has a groove  13   f  that conforms substantially to the upper groove  72  of the nutplate  15  within the faceted region  82 , such that rotation between the nutplate  15  and the housing  13  is prevented. 
     The figures illustrate the nutplate  15  having six contour regions and six anti-rotation features. Moreover, the figures illustrate the contour regions as being convex in top plan view and having a substantially round C-shaped cross-section in side view and the anti-rotation features as being faceted regions also having a substantially round C-shaped cross-section in side view. However, any number, shapes and sizes can be used for the contour regions and anti-rotation features, as long as the function of preventing rotation between the nutplate and the housing is achieved. For example, the anti-rotation feature may be ribbed, non-round shapes, etc. In one aspect, the diameter of the nutplate  15  will dictate the number of anti-rotation features, so that as the diameter increases, the number of anti-rotation features increases. 
     One embodiment of a method for forming the filter assembly  10  will now be described. Referring to  FIG. 6 , the disclosed method  100  first involves assembling the filter element  19  (step  102 ). The filter element  19  is assembled by disposing the filter media  30  around the center tube  35 , and securing the ends  30   a,    30   b  to the endplates  33 ,  37 . The filter element  19  is then placed within the inner space  25  of the housing  13  (step  104 ). Once the filter element  19  is placed within the housing  13 , the filter element  19  and the nutplate  15  are brought together by fitting the sleeve  64  of the filter element  19  within the central hub  50  of the nutplate  15  (step  106 ). 
       FIGS. 7A and 7B  show the state of the portions  13   c,    13   e  of the housing  13  prior to deformation into the upper groove  72  of the nutplate  15 .  FIG. 7A  shows a cross section of the contour region  84  and  FIG. 7B  shows a cross section of the faceted region  82 . The nutplate  15  is connected to the open end  13   b  of the housing  13  such that a flange  13   g  of the housing  13  is disposed within the groove  72  on the nutplate  15  (step  108 ). 
     In one implementation, a seamer machine is utilized for performing a seaming operation to radially deform the flange  13   g  so as to conform the flange  13   g  to the shape of the groove  72 . In one example, a profile roll is advanced into the flange  13  using a servo actuator within the seamer machine (step  110 ). The seaming operation is then performed so that the profile roll pushes the flange  13   g  inwardly toward the groove  72  (step  112 ). The profile roll then deforms the flange  13   g  to substantially conform the flange  13   g  to the shape of the groove  72  (step  114 ). In this instance, the servo actuator is capable of following the shape of the groove  72  both in the contour regions  84  and the faceted regions  82 , so as to prevent free rotation of the housing  13  relative to the nutplate  15 . 
     The disclosed method eliminates the need for a secondary operation to stake the housing to the nutplate, thereby allowing for a single machine process to produce a filter assembly with anti-rotation features. 
     While the disclosed filter assembly and methods have been described in conjunction with a preferred embodiment, it will be obvious to one skilled in the art that other objects and refinements of the disclosed filter assembly and methods may be made within the purview and scope of the disclosure. 
     The disclosure, in its various aspects and disclosed forms, is well adapted to the attainment of the stated objects and advantages of others. The disclosed details are not to be taken as limitations on the claims.