Patent Publication Number: US-10329992-B2

Title: Manifold sealing face for improved bellows installation

Description:
CROSS-REFRENCE TO RELATED APPLICATIONS 
     This application is a U.S. national stage application claiming the benefit of priority to International Application No. PCT/US2015/022245, filed on Mar. 24, 2015, entitled “Manifold Sealing Face for Improved Bellows Installation,” the entire disclosure of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates generally to the field of exhaust systems for internal combustion engines. 
     BACKGROUND 
     Exhaust systems for internal combustion engines include exhaust manifolds connected to cylinder heads of the engine. The exhaust manifolds collect post-combustion material (e.g., exhaust gas) from multiple cylinders of the engine and deliver the material to an exhaust pipe. In operation, exhaust manifolds are subject to highly variable temperatures. Temperature variations cause the exhaust manifolds to expand and contract, which may stress and ultimately damage the manifolds, seals, and other components. Thermal expansion may be particularly problematic for large engines with correspondingly long exhaust manifolds. To that end, exhaust systems for some engines utilize exhaust manifolds that are separated into several sections. The sections are coupled together using a flexible coupling, such as a bellows, that permits expansion and contraction between the sections. 
     SUMMARY 
     Various embodiments relate to exhaust manifold assemblies for use in routing exhaust gas from internal combustion engines. An example exhaust system includes a first manifold section, including a first body portion defining a first fluid passage. A first annular flange is disposed about a periphery of an end of the first body portion. The first annular flange has a first sealing face. An annular shoulder extends axially outward from the sealing face. A second manifold section includes a second body portion defining a second fluid passage. A second annular flange is disposed about a periphery of an end of the second body portion. The second annular flange has a second sealing face. A second annular shoulder extends axially outward from the second sealing face. A bellows extends between the first and second annular flanges and fluidly couples the first and second fluid passages. The bellows is removably coupleable to each of the first and second manifold sections. 
     Various other embodiments relate to a method of installing a bellows into an exhaust manifold assembly for use in routing exhaust gas from an internal combustion engine. The method includes providing the exhaust manifold assembly. The exhaust manifold assembly includes a first manifold section having a first annular flange. A first annular shoulder extends axially outward from the first annular flange. A second manifold section is spaced from the first manifold section. The second manifold section has a second annular flange. A second annular shoulder extends axially outward from the second annular flange. A bellows includes a third annular flange disposed about a periphery of a first end of the bellows. A fourth annular flange is disposed about a periphery of a second end of the bellows. A first gasket is positioned against the first annular flange and a second gasket is positioned against the second annular flange. The method also includes compressing the bellows. Next, the bellows are positioned such that the third annular flange of the bellows contacts the first annular shoulder of the first manifold section, and the fourth annular flange of the bellows contacts the second annular shoulder of the second manifold section. Finally, the bellows are moved along the first and second annular shoulders until the third and fourth annular flanges of the bellows align with the corresponding first and second annular flanges of the respective first and second manifold sections. 
     Various other embodiments relate to an internal combustion engine system. An example system includes an internal combustion engine and first and second manifold assemblies each in exhaust gas receiving communication with the internal combustion engine. Each of the first and second manifold assemblies includes first and second manifold sections. Each of the first and second manifold sections has a body portion and an annular flange disposed about a periphery of an end of the body portion. An annular shoulder extends axially outward from each annular flange. A bellows fluidly couples the first and second manifold sections. 
     These and other features, together with the organization and manner of operation thereof, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like elements have like numerals throughout the several drawings described below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a portion of an exhaust system, according to an embodiment. 
         FIG. 2  is a partial side view of the exhaust system of  FIG. 1 . 
         FIG. 3  is a partial cross-sectional view of the exhaust system of  FIG. 2 , taken along line  3 - 3 . 
         FIG. 4  is a partial exploded cross-sectional view of an interface between the first manifold section and the first bellows of the exhaust system of  FIGS. 1-3 . 
         FIG. 5  illustrates the first bellows being coupled to the first manifold section of the exhaust system of  FIGS. 1-4 . 
         FIG. 6  is a perspective view of the gasket of  FIGS. 3-5 . 
         FIG. 7  is a perspective view of the gasket of  FIGS. 3-6  positioned against the annular flange of the first manifold section. 
         FIG. 8  is a flow diagram of a method of installing bellows between exhaust manifold sections, according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a perspective view of a portion of an exhaust system  100 , according to an embodiment. As illustrated in  FIG. 1 , the exhaust system  100  includes first and second manifold assemblies  102 ,  104  operably coupled to and in exhaust gas communication with respective first and second cylinder heads  106 ,  108  of an engine. The first and second manifold assemblies  102 ,  104  are configured to convey exhaust gas from the respective first and second cylinder heads  106 ,  108  of the engine. The exhaust gas may be conveyed from the first and second manifold assemblies  102 ,  104  to various components (e.g., a turbocharger, an exhaust gas recirculation system, exhaust aftertreatment components, etc.) and eventually discharged into the atmosphere. According to various embodiments, the engine may be a compression ignition (e.g., diesel) or spark ignition (e.g., gasoline, compressed natural gas) engine, etc. As illustrated in  FIG. 1 , the exhaust system  100  is arranged for use with a V-engine. However, the exhaust system  100  may similarly be used with engines having in-line or other cylinder configurations. 
     As illustrated in  FIG. 1 , the first and second manifold assemblies  102 ,  104  extend generally along first and second central axes  110 ,  112 . The first and second central axes  110 ,  112  may be parallel or substantially parallel with a crankshaft of the engine (not shown). Each of the first and second manifold assemblies  102 ,  104  includes multiple manifold sections. For example, the first manifold assembly  102  includes, first, second, third, fourth, and fifth manifold sections  114 ,  116 ,  118 ,  120 ,  122 . Each of the first, second, third, fourth, and fifth manifold sections  114 ,  116 ,  118 ,  120 ,  122  includes a body portion defining a fluid passage extending therethrough. The first manifold assembly  102  also includes several bellows to fluidly couple each of the manifold sections. In particular, a first bellows  124  fluidly couples the fluid passages of the first and second manifold sections  114 ,  116 , a second bellows  126  fluidly couples the fluid passages of the second and third manifold sections  116 ,  118 , a third bellows  128  fluidly couples the fluid passages of the third and fourth manifold sections  118 ,  120 , and a fourth bellows  130  fluidly couples the fluid passages of the fourth and fifth manifold sections  120 ,  122 . Typically, the bellows are compressed between manifold sections and gaskets (not shown) are installed between each manifold section/bellows interface to fluidly seal the interface. The first, second, third, and fourth bellows  124 ,  126 ,  128 ,  130  permit relative displacement, both axially and transversely, between manifold sections. For example, manifold sections may experience relative displacement therebetween due to thermal expansion, vibration, slight assembly misalignments, etc. The bellows permit such displacement, which could otherwise damage conventional, unitary exhaust manifolds. 
     The manifold sections and bellows may be removably coupled in various ways. In one embodiment, as shown in  FIG. 1 , v-bands, or “Marman clamps” are utilized to removably couple the manifold sections and bellows, and to compress and retain gaskets therebetween. In other embodiments, flanges of the respective manifold sections and bellows are bolted together. As illustrated in  FIG. 1 , a first v-band clamp  132  removably couples the first manifold section  114  to a first end of the first bellows  124 , a second v-band clamp  134  removably couples a first end of the second manifold section  116  to a second end of the first bellows  124 , etc. 
     Conventionally, manifold assemblies are assembled sequentially from end-to-end or outwards from the center, with gaskets (not shown) compressed between each manifold section/bellows interface. For example, to assemble the first manifold assembly  102 , the first manifold section  114  is coupled to the first cylinder head  106 , then the first bellows  124  is coupled to the first manifold section  114 , then the second manifold section  116  is coupled to each of the first cylinder head  106  and the first bellows  124 , etc. Alternatively, the first manifold assembly  102  may be installed from the other end. For example, the fifth manifold section  122  is coupled to the first cylinder head  106 , then the fourth bellows  130  is coupled to the fifth manifold section  122 , then the fourth manifold section  120  is coupled to each of the first cylinder head  106  and the fourth bellows  130 , etc. In another example, the first manifold assembly  102  may be installed outwards from the center. For example, the third manifold section  118  is coupled to the first cylinder head  106 ; then the second and third bellows  126 ,  128  are coupled to corresponding ends of the third manifold section  118 ; then the second manifold section  116  is coupled to each of the first cylinder head  106  and the second bellows  126 , and the fourth manifold section  120  is coupled to each of the first cylinder head  106  and the third bellows  128 , etc. 
     Periodically, the exhaust system  100  or portions thereof may need to be removed to service the engine and/or the exhaust system. For example, a cylinder head or gasket may need to be repaired or replaced, or a bellows or manifold gasket may need to be repaired or replaced. However, removing bellows in a service environment may be difficult. One way to remove a bellows is to remove all manifold sections and bellows adjacent one side of the bellows. However, this procedure is labor intensive and time consuming, and may require removal of other adjacent components. Another option is to remove the bellows without removing adjacent manifold sections. However, this is also challenging because the bellows must be compressed in order to be removed and again to be reinstalled. Specialized service tools may be used for this process; however, these tools may be expensive and not all shops may have access to them. Accordingly, providing access to the specialized service tools for every service technician is a significant added cost. Further, different bellows sizes and configurations may require different tools. In addition, if the bellows are removed without removing the adjacent manifold sections, it may be difficult to retain and position the gasket when reinstalling the bellows. For example, the bellows flange may damage or displace the gasket during installation, thereby compromising the sealing capability of the gasket. 
     According to various embodiments, an exhaust manifold sealing face is provided for improved bellows installation. The manifold section includes a shoulder, or pilot, that extends axially outward from a sealing face of an annular flange of the manifold section. The shoulder is configured to act as a guide for the bellows flange to move (e.g., slide) on as it is being compressed and installed between manifold sections, thereby protecting the gasket from being damaged by the bellows. The shoulder also includes gasket retention features to retain the gasket in position as the bellows is being installed. The shoulder is sized such that the bellows flange does not touch or disrupt the gasket as the bellows is being installed. Although the embodiments described herein include sealing faces for exhaust manifolds, other embodiments include sealing faces of other fluid passages or pipe joints. For example, certain embodiments relate to sealing joints of exhaust pipes downstream of the manifold. In addition, some embodiments include flexible joints or couplings other than bellows. 
       FIG. 2  is a partial view of the exhaust system  100  of  FIG. 1 , including the first and second manifold sections  114 ,  116 ; the first bellows  124 ; and the first and second v-band clamps  132 ,  134 . The first manifold section  114  includes a first body portion  115 . The first body portion  115  defines a first fluid passage (not shown) extending therethrough. Similarly, each of the second manifold section  116  and the first bellows  124  include respective second and third body portions  117 ,  119 . The second and third body portions  117 ,  119  respectively define second and third fluid passages (not shown) extending therethrough. 
       FIG. 3  is a partial cross-sectional view of the exhaust system  100  of  FIG. 2 , taken along line  3 - 3 . As shown in  FIG. 3 , the first bellows  124  fluidly couples the first and second manifold sections  114 ,  116 . The first bellows  124  includes a first sleeve portion  135  that defines a first flange  136  extending radially outward from the first sleeve portion  135  at a first end  138  of the first bellows  124 . The first bellows  124  also includes a second sleeve portion  140  that similarly defines a second flange  142  extending radially outward from a second end  144  of the first bellows  124 . The first and second sleeve portions  135 ,  140  are separated by a gap  146 . The first and second sleeve portions  135 ,  140  may be formed of metal (e.g., steel or aluminum), polymer-based, or composite tubing bent or otherwise formed as illustrated in  FIG. 3 . In some implementations, thermal requirements, for example, may drive material selection. Some embodiments similarly include couplings other than bellows. 
     The first bellows  124  also includes a flexible member  148  coupling the first and second sleeve portions  135 ,  140  and disposed on an outer periphery thereof. The flexible member  148  may be fixedly attached (e.g., bonded, adhered, etc.) to the outer periphery of each of the first and second sleeve portions  135 ,  140 . The flexible member  148  may be formed of rubber or other flexible materials. As illustrated in  FIG. 3 , the flexible member  148  may include a wavy or convoluted surface that facilitates the flexibility of the flexible member  148 . For example, the flexible member  148  of the first bellows  124 , as well as the gap  146  between the first and second sleeve portions  135 ,  140 , allows the first bellows  124  to expand, contract, and otherwise move axially and transversely due to thermal expansion, vibration, misalignment, etc. 
       FIG. 4  is a partial exploded cross-sectional view of an interface between the first manifold section  114  and the first bellows  124  of the exhaust system  100  of  FIGS. 1-3 . In addition to the first manifold section  114  and the first bellows  124 , the interface also includes a gasket  150  and a retainer  152  of the first bellows  124 . It is important to note that only a portion of the interface is shown in  FIG. 4 . It should be understood that each of the first manifold section  114 , the first bellows  124 , the gasket  150 , and the retainer  152  extend annularly about the first central axis  110  ( FIG. 1 ). However, the first manifold section  114  and the first bellows  124  need not extend annularly about the first central axis  110  ( FIG. 1 ) for their entire length. Instead, any of the manifold sections and bellows, including the first manifold section  114  and the first bellows  124 , may include bends or curves. 
     The first manifold section  114  includes an annular flange  154  disposed about and extending radially outwardly from a periphery of a first end  156  of the first manifold section  114 . The annular flange  154  defines a sealing face  158 . The first manifold section  114  also includes an annular shoulder  160  that extends axially outward from the sealing face  158 . The annular shoulder  160  is positioned radially inward of the sealing face  158 . The annular flange  154  also defines a notch  162  extending axially inward from the sealing face  158  at a radially outward-most portion of the annular flange  154 . A chamfered edge  164  extends between the sealing face  158  and the notch  162 . 
     The first flange  136  of the first bellows  124  defines a sealing face  166 . In operation, the gasket  150  is sandwiched between the sealing face  158  of the first manifold section  114  and the sealing face  166  of the first bellows  124  to provide a fluid seal therebetween. For example, the retainer  152  is configured to engage the first flange  136  of the first bellows  124  to compress the gasket  150  between the sealing faces  158 ,  166  of the first manifold section  114  and the first bellows  124 . The gasket  150  may be formed from any of several materials, such as graphite, rubber, silicone, polymers, etc. In some implementations, the gasket  150  is deformable, compressible, and/or resilient. The retainer  152  also includes a lip  165  that extends into the notch  162  of the annular flange  154 . 
     Returning briefly to  FIG. 3 , the first v-band clamp  132  includes an inner surface  167  configured to engage each of an outer clamping surface  168  of the retainer  152  and an outer clamping surface  170  of the annular flange  154  of the first manifold section  114 . Upon installation, the v-band clamp forces the first flange  136  of the first bellows  124  towards the annular flange  154  of the first manifold section  114  to compress the gasket  150  between the corresponding sealing faces  158 ,  166  of the respective flanges  136 ,  154 . 
     Turning to  FIG. 5 , the first bellows  124  being coupled to the first manifold section  114  is illustrated. In order to install the first bellows  124  between the first and second manifold sections  114 ,  116 , the first bellows  124  is compressed and the sealing face  166  of the first bellows  124  is positioned against the annular shoulder  160  of the first manifold section  114 . The annular shoulder  160  is configured to operate as a pilot, or guide, to prevent the first flange  136  of the first bellows  124  from touching and/or damaging the gasket  150  as the first bellows  124  is being coupled to the first manifold section  114 . The annular shoulder  160  extends axially outward from the sealing face  158  of the first manifold section  114  by a first length. The first length of the annular shoulder  160  is sized to provide a clearance between the first flange  136  of the first bellows  124  and the gasket  150 . In one embodiment, the first length is at least twice the thickness of the gasket  150 . In another embodiment, the first length is at least three times the thickness of the gasket  150 . In some embodiments, the first length is further dependent on a diameter of the first bellows  124 . The first length may also be dependent on a size of the sealing face  158  and/or a width of the gasket  150 , among other factors. The annular shoulder  160  may include a radius or chamfer to help guide the first flange  136  of the first bellows  124  onto the annular shoulder  160 . 
       FIG. 6  is a perspective side view of the gasket  150  of  FIGS. 3-5 . As shown in  FIG. 6 , in some embodiments, the gasket  150  includes one or more retention ribs  172  extending radially inward from an inner radial face  174  of the gasket  150 . 
       FIG. 7  is a perspective view of the gasket  150  of  FIGS. 3-6  positioned against the annular flange  154  of the first manifold section  114 . As illustrated in  FIG. 7 , according to an embodiment, the annular shoulder includes an outer radial face  176  defining retention features  178  extending radially inward from the outer radial face  176 . The retention features  178  are sized, shaped, and positioned to accept the retention ribs  172  of the gasket  150 . The interface between the retention ribs  172  and the retention features  178  operates to retain the gasket  150  against the annular flange  154  of the first manifold section  114  as the first bellows  124  is being coupled to the first manifold section  114 . In some embodiments, the retention features  178  include dimples positioned about the outer radial face  176 . In other embodiments, the retention features  178  include a notch extending radially inward from the outer radial face  176 . The dimples may operate to restrict the rotational position of the gasket  150 , while the notch may allow rotation of the gasket  150 . In some embodiments, the gasket  150  has an inner diameter that is equal to or slightly smaller than an outer diameter of the annular shoulder  160  such that an interference fit between the gasket  150  and the annular shoulder  160  further operates to retain the gasket  150  against the annular flange  154  of the first manifold section  114 . Accordingly, the annular flange  154  and the gasket  150  overcome problems associated with conventional exhaust bellows systems related to gaskets becoming misaligned or misplaced during bellows installation. 
       FIG. 8  is a flow diagram of a method  200  of installing bellows between exhaust manifold sections, according to an embodiment. For example, the method  200  may be performed to install the first bellows  124  between the first and second manifold sections  114 ,  116 . However, the method  200  is not limited to this embodiment and may similarly be performed using other components. 
     At  202 , an exhaust system is provided. The exhaust system includes first and second manifold sections and a bellows. In an embodiment, the first manifold section includes a first annular flange and a first annular shoulder extending axially outward from the first annular flange. The second manifold section is spaced from the first manifold section. The second manifold section includes a second annular flange and a second annular shoulder extending axially outward from the second annular flange. The bellows includes third and fourth annular flanges. The third annular flange is disposed about a periphery of a first end of the bellows. The fourth annular flange is disposed about a periphery of a second end of the bellows. 
     At  204 , gaskets are positioned against the first and second annular flanges. More specifically, a first gasket is positioned against the first annular flange and a second gasket is positioned against the second annular flange. Each of the first and second gaskets may be positioned against sealing faces of the respective first and second annular flanges. 
     At  206 , the bellows is compressed. Because the bellows is flexible, the bellows can be compressed by forcing the first and second ends of the bellows towards each other. 
     At  208 , the bellows is positioned such that the third annular flange of the bellows contacts the first annular shoulder of the first manifold section, and the fourth annular flange of the bellows contacts the second annular shoulder of the second manifold section. 
     At  210 , the bellows is moved (e.g., slid) along the first and second annular shoulders until the third and fourth annular flanges of the bellows align with the corresponding first and second annular flanges of the respective first and second manifold sections. The first and second annular shoulders are sized to provide clearances between the third and fourth annular flanges of the bellows and the first and second gaskets. Accordingly, the first and second annular shoulders protect the first and second gaskets from being damaged as the bellows is installed. 
     Once the bellows is positioned and aligned between the first and second manifold sections, v-band clamps may be installed to retain the bellows in place. For example, regarding the first manifold section, a retainer is positioned against an outer surface of the third annular flange of the bellows. A v-band clamp is positioned over each of the first annular flange of the first manifold section and the retainer. Finally, the v-band clamp is tightened to compress the gasket between the first annular flange and the third annular flange. The bellows can be removed by reversing the method  200  described above. 
     While this specification contains many specific implementation details, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of features specific to particular implementations. Certain features described in this specification in the context of separate implementations or embodiments can also be implemented in combination in a single implementation or embodiment as would be understood by one of ordinary skill in the art. Conversely, various features described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. 
     As utilized herein, the term “substantially” and any similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided unless otherwise noted. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims. Additionally, it is noted that limitations in the claims should not be interpreted as constituting “means plus function” limitations under the United States patent laws in the event that the term “means” is not used therein. 
     The terms “coupled,” “connected,” and the like as used herein mean the joining of two components directly or indirectly to one another. Such joining may be stationary (e.g., permanent) or moveable (e.g., removable or releasable). Such joining may be achieved with the two components or the two components and any additional intermediate components being integrally formed as a single unitary body with one another or with the two components or the two components and any additional intermediate components being attached to one another. 
     It is important to note that the construction and arrangement of the system shown in the various exemplary implementations is illustrative only and not restrictive in character. All changes and modifications that come within the spirit and/or scope of the described implementations are desired to be protected. It should be understood that some features may not be necessary and implementations lacking the various features may be contemplated as within the scope of the application, the scope being defined by the claims that follow. It should be understood that features described in one embodiment could also be incorporated and/or combined with features from another embodiment in manner understood by those of ordinary skill in the art. It should also be noted that the terms “example” and “exemplary” as used herein to describe various embodiments are intended to indicate that such embodiments are possible examples, representations, and/or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples).