Abstract:
A seal conforms to a surface geometry that enables the seal to meet performance objectives with a large number of material compositions. A corresponding seal system includes the seal having the surface geometry inside a groove defined by a member.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates to gaskets and seals for providing sealed connections between components. 
       BACKGROUND OF THE INVENTION 
       [0002]    Seals and gaskets are employed in various components to prevent fluids from leaking outside of the component and to prevent contaminants from entering the component. The performance of a seal depends upon the geometry of the seal and the material comprising the seal. Accordingly, a seal geometry that meets performance objectives with one material may not meet performance objectives with another material. Exemplary performance objectives include contact pressure, contact width, and strain limits. 
       SUMMARY OF THE INVENTION 
       [0003]    A seal includes a seal body having an outer surface that conforms to a profile tolerance of 0.2 millimeters of an ideal surface geometry. The ideal surface geometry has first, second, third, fourth, fifth, and sixth points thereon. The ideal surface geometry also has first, second, third, fourth, and fifth segments, and is characterized by a first plane of symmetry and a second plane of symmetry. The first plane of symmetry intersects the ideal surface geometry at the first point, and the second plane of symmetry, which is substantially perpendicular to the first plane of symmetry, intersects the ideal surface geometry at the sixth point. 
         [0004]    The first segment is an arc that has a radius of 17.50 millimeters and that connects the first point and the second point. The second segment is linear, has a length of 1.68 millimeters, and connects the second point to the third point. The third segment is an arc that has a radius of 2.40 millimeters, and that connects the third point to the fourth point. The fourth segment is an arc that has a radius of 0.66 millimeters, and that connects the fourth point to the fifth point. The fifth segment is an arc that has a radius of 2.20 millimeters, and that connects the fifth point to the sixth point. 
         [0005]    The seal provided herein meets performance objectives for at least twenty-five different elastomer compositions and formulations. Accordingly, the seal provided herein provides a standardized design that may be used across a wide variety of applications and in a wide variety of operating environments, thereby eliminating the engineering and testing costs that may be associated with prior art seals. 
         [0006]    According to another aspect of the disclosure, a seal body has an outer surface that conforms to a profile tolerance of 0.2 millimeters of an ideal surface geometry. The ideal surface geometry has first, second, third, fourth, fifth, sixth, and seventh points thereon, and has first, second, third, fourth, fifth, and sixth segments. A first plane of symmetry intersects the ideal surface geometry at the first point, and a second plane of symmetry, which is substantially perpendicular to the first plane of symmetry, intersects the ideal surface geometry at the seventh point. 
         [0007]    The first segment is linear, has a length of 1.220 millimeters, and connects the first point and the second point. The second segment is an arc having a radius of 3.000 millimeters, and connects the second point to the third point. The third segment is linear, has a length of 1.450 millimeters, and connects the third point to the fourth point. The fourth segment is an arc having a radius of 1.430 millimeters, and connects the fourth point to the fifth point. The fifth segment is an arc having a radius of 0.645 millimeters, and connects the fifth point to the sixth point. The sixth segment is an arc having a radius of 1.890 millimeters, and connects the sixth point to the seventh point. 
         [0008]    The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a schematic, cross-sectional view of a first member defining a groove, and a seal disposed within the groove; 
           [0010]      FIG. 2  is a schematic depiction of the surface geometry of the seal of  FIG. 1  at the cross-sectional plane of  FIG. 1 ; 
           [0011]      FIG. 3  is a schematic, cross-sectional view of the first member of  FIG. 1 ; 
           [0012]      FIG. 4  is a schematic, cross-sectional view of the first member and seal of  FIG. 1  with a second member beginning to engage the seal; 
           [0013]      FIG. 5  is a schematic, cross-sectional view of the first member, seal, and second member of  FIG. 4 , with the second member mounted to the first member and compressing the seal; 
           [0014]      FIG. 6  is a schematic depiction of the surface geometry of an alternative seal configuration in accordance with the claimed invention; 
           [0015]      FIG. 7  is a schematic, side view of the seal having the surface geometry of  FIG. 6 ; 
           [0016]      FIG. 8  is a schematic depiction of the surface geometry of a retention feature of the seal of  FIG. 7 ; and 
           [0017]      FIG. 9  is a schematic depiction of the surface geometry of a stabilization feature of the seal of  FIG. 7 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    Referring to  FIG. 1 , a gasket or seal  10  for providing a sealing connection between a first member  14  and a second member (shown at  16  in  FIGS. 4 and 5 ) is schematically depicted. The first member  14  defines a groove  18  in which the seal  10  is at least partially disposed. The outer surface  22  of the seal  10  is within 0.2 millimeters of an ideal surface geometry, and preferably conforms to within 0.15 millimeters of the ideal surface geometry. That is, the seal  10  conforms to a profile tolerance of 0.2 millimeters of the ideal surface geometry. Preferably, the seal  10  conforms to a profile tolerance of 0.15 millimeters of the ideal surface geometry. The ideal surface geometry of the outer surface  22  of seal  10  is symmetrical about a first plane of symmetry  26  and a second plane of symmetry  30 . 
         [0019]    The first and second planes  26 ,  30  of symmetry are perpendicular to one another. The two points  34 ,  38  of the ideal surface geometry that are in plane  26  are 2.52 millimeters apart, i.e., the width of the seal  10  having the ideal surface geometry is 2.52 millimeters. The two points  40 ,  42  of the ideal surface geometry that are in plane  30  are 7.82 millimeters apart, i.e., the height of the seal  10  having the ideal surface geometry is 7.82 millimeters. 
         [0020]    Referring to  FIG. 2 , a segment  44 A of the ideal surface geometry connects point  34  to point  46 A, and is an arc characterized by a radius R 1  of 17.50 millimeters. Linear segment  48 A of the ideal surface geometry connects point  46 A to point  50 A and is characterized by a length L 1  of 1.68 millimeters. Segment  52 A of the ideal surface geometry connects point  50 A to point  54 A, and is an arc characterized by a radius R 2  of 2.4 millimeters. Segment  56 A of the ideal surface geometry connects point  54 A to point  58 A and is an arc characterized by a radius R 3  of 0.66 millimeters. Segment  60 A of the ideal surface geometry connects point  58 A to point  40 , and is an arc characterized by a radius R 4  of 2.20 millimeters. The ideal surface geometry at point  40  is substantially parallel to plane of symmetry  26 . The distance L 2  from point  40  to plane  26  is 3.91 millimeters. 
         [0021]    The remainder of the ideal surface geometry can be determined by the ideal surface geometry between points  34  and  40  because of the symmetry about planes  26  and  30 . More specifically, and with reference to  FIG. 4 , a segment  44 B of the ideal surface geometry connects point  38  to point  46 B, and is an arc characterized by a radius of 17.50 millimeters. Linear segment  48 B of the ideal surface geometry connects point  46 B to point  50 B and is characterized by a length of 1.68 millimeters. Segment  52 B of the ideal surface geometry connects point  50 B to point  54 B, and is an arc characterized by a radius of 2.4 millimeters. Segment  56 B of the ideal surface geometry connects point  54 B to point  58 B and is an arc characterized by a radius of 0.66 millimeters. Segment  60 B of the ideal surface geometry connects point  58 B to point  40 , and is an arc characterized by a radius of 2.20 millimeters. 
         [0022]    A segment  44 C of the ideal surface geometry connects point  34  to point  46 C, and is an arc characterized by a radius of 17.50 millimeters. Linear segment  48 C of the ideal surface geometry connects point  46 C to point  50 C and is characterized by a length of 1.68 millimeters. Segment  52 C of the ideal surface geometry connects point  50 C to point  54 C, and is an arc characterized by a radius of 2.4 millimeters. Segment  56 C of the ideal surface geometry connects point  54 C to point  58 C and is an arc characterized by a radius of 0.66 millimeters. Segment  60 C of the ideal surface geometry connects point  58 C to point  42 , and is an arc characterized by a radius of 2.20 millimeters. 
         [0023]    Segment  44 D of the ideal surface geometry connects point  38  to point  46 D, and is an arc characterized by a radius of 17.50 millimeters. Linear segment  48 D of the ideal surface geometry connects point  46 D to point  50 D and is characterized by a length of 1.68 millimeters. Segment  52 D of the ideal surface geometry connects point  50 D to point  54 D, and is an arc characterized by a radius of 2.4 millimeters. Segment  56 D of the ideal surface geometry connects point  54 D to point  58 D and is an arc characterized by a radius of 0.66 millimeters. Segment  60 D of the ideal surface geometry connects point  58 D to point  42 , and is an arc characterized by a radius of 2.20 millimeters. 
         [0024]    Referring to  FIG. 3 , the seal  10  is configured for use inside a standardized groove  18 . Groove  18  is characterized by a width W of 3.9 millimeters and a height H of 6 millimeters. The lateral walls of the groove  18  are not parallel, but rather diverge at an angle α of 1°. The seal  10  may be used with other groove configurations within the scope of the claimed invention. 
         [0025]    Referring to  FIGS. 4 and 5 , the second member  16  contacts the seal  10  at point  40  during attachment of the second member  16  to the first member  14 . The seal  10  is not compressed in  FIG. 4 . As the second member  16  is pressed toward the first member, the second member  16  compresses the seal  10 , as shown in  FIG. 5 . The contact area between member  16  and the seal  10  prevents the passage of fluids from one side of the seal  10  to the other. Those skilled in the art will recognize a variety of applications in which the seal  10  may be employed within the scope of the claimed invention. For example, member  14  may be part of a pump, an oil pan, a cam cover, etc. 
         [0026]    As shown in  FIG. 5 , there are gaps between the compressed seal  10  and the lateral walls of the groove  18  at the section shown. Within the scope of the claimed invention, parts of the seal  10  (e.g., at various spaced intervals along the length of the seal) may deviate from the profile tolerance of 0.2 millimeters of the ideal surface geometry to provide more contact between the seal and the walls of the groove  18  in order to enhance retention of the seal  10  within the groove  18 . 
         [0027]    Referring to  FIG. 6 , wherein like reference numbers refer to like components from  FIGS. 1-5 , an alternative seal  10 A is schematically depicted. The outer surface  22 A of the seal  10 A is within 0.2 millimeters of another ideal surface geometry, which is shown in  FIG. 6 , and preferably conforms to within 0.15 millimeters of the ideal surface geometry. That is, the seal  10 A conforms to a profile tolerance of 0.2 millimeters of the ideal surface geometry. Preferably, the seal  10 A conforms to a profile tolerance of 0.15 millimeters of the ideal surface geometry. The ideal surface geometry of the outer surface  22 A of seal  10 A is symmetrical about a first plane of symmetry  26  and a second plane of symmetry  30 . 
         [0028]    The first and second planes  26 ,  30  of symmetry are perpendicular to one another. Planes  26  and  30  bisect the seal  10 A. Plane  26  intersects the surface  22 A at two points  64 ,  68 . Plane  30  intersects the surface  22 A at two points, only one of which is shown at  72 . The distance L 3  from plane  26  to point  72  is 3.914 millimeters. Thus, seal  10 A with the ideal surface geometry has a total height of 7.828 millimeters. The distance L 4  from plane  30  to point  68  is 1.205 millimeters. Thus, the seal  10 A with the ideal surface geometry has a total width of 2.410 millimeters. 
         [0029]    A segment  76  of the ideal surface geometry connects point  68  to point  80 . Segment  76  is linear and is characterized by a length L 5  of 1.220 millimeters. Segment  84  of the ideal surface geometry connects point  88  to point  80 , and is an arc characterized by a radius R 5  of 3.000 millimeters. Linear segment  92  of the ideal surface geometry connects point  88  to point  96  and is characterized by a length L 6  of 1.450 millimeters. Segment  100  of the ideal surface geometry connects point  96  to point  104 , and is an arc characterized by a radius R 6  of 1.430 millimeters. Segment  108  of the ideal surface geometry connects point  104  to point  112  and is an arc characterized by a radius R 7  of 0.645 millimeters. Segment  116  of the ideal surface geometry connects point  112  to point  72 , and is an arc characterized by a radius R 8  of 1.890 millimeters. The ideal surface geometry at point  72  is substantially parallel to plane of symmetry  26 . The remainder of the ideal surface geometry of seal  10 A can be determined by the ideal surface geometry between points  68  and  72  because of the symmetry about planes  26  and  30 . 
         [0030]    The dimensions of the seals  10 ,  10 A are such that the seals  10 ,  10 A meet a wide variety of sealing performance objectives with a wide variety of elastomer material compositions. For example, seals  10 ,  10 A may comprise ethylene propylene diene monomer (EPDM), fluoroelastomers, alkyl acrylate copolymer, nitrile butadiene rubber (NBR), ethylene acrylic elastomer, etc. Those skilled in the art will recognize other elastomers that may be employed within the scope of the claimed invention. 
         [0031]    Referring to  FIG. 7 , wherein like reference numbers refer to like components from  FIGS. 1-6 , the surface  22 A of seal  10 A is characterized by retention features  120 , which interact with the walls of the groove (shown at  18  in FIGS.  1  and  3 - 5 ) to retain the seal  10 A within the groove, and stability features  124 , which interact with the walls of the groove to maintain proper orientation of the seal  10 A during assembly of member  16  to member  14 . Retention features  120  and stabilization features  124  are locally widened portions of the seal  10 A. The seal geometry shown in  FIG. 6  is representative of the seal geometry at any vertical cross-section taken between the retention features  120  and stabilization features  124 . 
         [0032]      FIG. 8  schematically depicts the surface geometry of the seal  10 A at the widest portion of the retention feature  120 , i.e., at section  8 - 8 . Referring to  FIG. 8 , wherein like reference numbers refer to like components from  FIGS. 1-7 , the outer surface  22 A of the seal  10 A at the retention feature  120  includes linear segments  128  and  132 . Segment  128  is parallel with the plane of symmetry  30  and is partially coextensive with line  136 . Segment  128  is displaced a distance L 8  of 2.200 millimeters from plane  30 , and thus, at the maximum width of retention feature  120 , the width of the seal  10 A is 4.400 millimeters. 
         [0033]    Segment  132  is partially coextensive with line  142 . Lines  136  and  142  intersect at point  146 . Point  146  is a distance L 7  of 1.330 millimeters from plane of symmetry  26 . Segments  128  and  132  form an angle α 1  of 135 degrees therebetween. A segment  150  of surface  22 A is an arc that extends between segments  128  and  132 . Segment  150  is characterized by a radius R 9  of 0.500 millimeters. Segment  154  of surface  22 A is an arc that extends on the opposite side of segment  132  from segment  150 . Segment  154  is characterized by a radius R 10  of 0.500 millimeters. 
         [0034]    The retention feature  120  includes segments  128 ,  150 ,  132 , and  154 . The seal  10 A is symmetrical about plane  26 , and thus the geometry of the retention feature  120  on the opposite side of plane  26  can be determined by the geometry of segments  128 ,  150 ,  132 , and  154 . The seal  10 A, being symmetrical about plane  30 , includes two retention features, as shown in  FIG. 8  on opposite sides of plane  30 . The remainder of the outer surface  22 A at section  8 - 8  conforms to the geometry shown in  FIG. 6 . 
         [0035]      FIG. 9  schematically depicts the surface geometry of the seal  10 A at the widest portion of one of the stabilization features  124 , i.e., at section  9 - 9  (shown in  FIG. 7 ). Referring to  FIG. 9 , wherein like reference numbers refer to like components from  FIGS. 1-8 , the outer surface  22 A of the seal  10 A at the stabilization feature  124  includes linear segments  158  and  162 . Segment  158  is parallel with the plane of symmetry  30  and is partially coextensive with line  166 . Segment  158  is displaced a distance L 10  of 1.850 millimeters from plane  30 , and thus, at the maximum width of stabilization feature  124 , the width of the seal  10 A is 3.700 millimeters. 
         [0036]    Segment  162  is partially coextensive with line  170 . Lines  166  and  170  intersect at point  174 . Point  174  is a distance L 9  of 1.680 millimeters from plane of symmetry  26 . Segments  158  and  162  form an angle a 2  of 135 degrees therebetween. A segment  178  of surface  22 A is an arc that extends between segments  158  and  162 . Segment  178  is characterized by a radius R 11  of 0.500 millimeters. Segment  182  of surface  22 A is an arc that extends on the opposite side of segment  162  from segment  178 . Segment  182  is characterized by a radius R 12  of 0.500 millimeters. 
         [0037]    The stabilization feature  124  includes segments  158 ,  178 ,  162 , and  182 . The seal  10 A is symmetrical about plane  26 , and thus the geometry of the stabilization feature  124  on the opposite side of plane  26  can be determined by the geometry of segments  158 ,  178 ,  162 , and  182 . The seal  10 A, being symmetrical about plane  30 , includes two stabilization features on opposite sides of plane  30 , as shown in  FIG. 9 . The remainder of the outer surface  22 A at section  9 - 9  conforms to the geometry shown in  FIG. 6 . 
         [0038]    While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.