Patent Publication Number: US-2022234439-A1

Title: Fuel system with neck support debris mitigation

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This application relates to fuel systems that have fuel tanks supported at a neck portion and to components and sub-assemblies therefor. 
     Description of the Related Art 
     Compressed natural gas (CNG) is an alternative fuel that provides many advantages. CNG fuels burn cleaner than other combustion fuels. CNG also can be more cost effective. 
     CNG fuel systems can come in several forms. One form employs a Type IV fuel tank constructed with a polymeric liner. Carbon fiber wrapped around the liner can reinforce the liner, to produce a fuel tank strong enough for use on heavy-duty trucks and other vehicles. The fuel tank can have a boss disposed at one or more ends for sealing the end portion(s) of the fuel tank. The boss can provide access to the fuel tank for filling and dispensing the fuel contained therein. The fuel tank can be integrated into a fuel system that includes a frame to support the fuel tank. The frame can support the fuel tank on a side or lateral portion of a vehicle, behind the cab of the vehicle, on a rooftop of the vehicle, or at another location. Some fuel tanks can be supported at one or both ends at the bosses. 
     SUMMARY OF THE INVENTION 
     Fuel tanks that are supported at one or more bosses can be subject to wear at the interface between the boss and the support. For example, in some cases it is observed that the fuel tank can expand and contract by small but significant amounts in a lengthwise direction. The expansion and contraction can be due to conditions such as the level of pressure in the tank, the temperature of the tank, the ambient temperature and other surrounding environmental conditions, or loading of the fuel tank. The expansion and contraction can cause relative sliding motion that can result in wear on the fuel tank, e.g., on a surface of the boss. While the fuel tank can be configured for a long service life accounting for wear, it would be an advantage to reduce fuel tank wear for a number of reasons, such as reducing maintenance and repair costs and preventing sudden material failure. 
     In one embodiment, a fuel system is provided that includes a tank, a mounting assembly, a first bearing block, and a second bearing block. The tank has a first boss at one end and a second boss. The second boss is located at an end of the tank opposite the first boss. The mounting assembly is configured to be coupled to a support. For example, the mounting assembly can be directly coupled to a vehicle, such as to a frame rail or can be indirectly coupled to a frame rail or a chassis portion of a vehicle by one or more other brackets or structural members. The mounting assembly can be configured to be coupled to a trailer or a stationary storage facility. The first bearing block is coupled to the mounting assembly. The first bearing block has a first inner portion comprising a first tank support surface and a wiper disposed adjacent to the first tank support surface. The second bearing block is coupled to the mounting assembly. The second bearing block has a second inner portion comprising a second tank support surface. The first bearing block being coupled to an outer surface of the first boss at the first tank support surface to form a first support connection. The second bearing block being coupled to an outer surface of the second boss at the second tank support surface to form a second support connection. The first and second support connections support the tank on the mounting assembly. The first bearing block allow the first boss to move relative to the first tank support surface while the tank is coupled to the mounting assembly. The wiper prevents debris from entering a space disposed between the first tank support surface and the first boss when the first boss move relative to the first support surface. 
     In another embodiment, a fuel system is provided that includes a mounting block assembly configured to support an end of a fuel tank. The end of the fuel tank has a boss. The mounting block assembly has a first portion and a second portion. The second portion is separable from the first portion. The first portion and the second portion enclose a space configured to receive the boss of the fuel tank. The fuel system also includes a bearing disposed in the space. The bearing has a support surface configured for sliding support of the boss of the fuel tank at an interface between the first portion and the second portion of the mounting block assembly. The bearing has an inboard facing surface. The inboard facing surface faces the end of the fuel tank when the fuel tank is supported by the mounting block assembly. The bearing has a wiper disposed adjacent to the support surface. 
     In another embodiment, a neck mount support assembly is provided that includes a mounting block assembly that is configured to support an end of a fuel tank. The end of the fuel tank has a boss. The mounting block assembly has a first portion and a second portion separable from the first portion. The first portion and the second portion enclose a space configured to receive the boss of the fuel tank. A bearing is disposed in the space. The bearing has a support surface configured for sliding support of the boss of the fuel tank at an interface. The mounting block has a wiper disposed adjacent to the support surface of the bearing. The wiper is configured to limit debris from entering the interface between the support surface and the boss. 
     In another embodiment a neck mount support assembly is provided that includes a mounting block and an end cap. The mounting block can be configured to support an end of a fuel tank, e.g., an end having a boss. The mounting block has a first portion and a second portion separable from the first portion. The first portion and the second portion enclose a bearing support space configured to receive the boss of the fuel tank. A bearing can be or is disposed in the bearing support space. The bearing has a support surface configured to support the boss of the fuel tank at an interface. The endcap can be connected to an outboard side of the mounting block opposite the side of the mounting block configured to face the fuel tank. The endcap can be configured to limit debris from entering the interface between the support surface and the boss. 
     In one variation, the neck mount support assembly can include a debris exclusion component on an inboard side of the mounting block facing the fuel tank. The debris exclusion component can include a cover. The cover can be connected to a first side of the mounting block. The first side can be the inboard side of the mounting block. The cover can be configured to limit debris from entering the interface between the support surface and the boss. 
     A cover, if provided, can span a length of the boss between the mounting block and the fuel tank enclosure. The cover can be secured to an outer surface of the fuel tank assembly. 
     A debris exclusion component on an inboard side of the neck mount support assembly can include a wiper disposed in mounting block, e.g., between the bearing and the boss. The wiper can be used alone or in combination with a cover that can cooperate to exclude debris from entering the interface between the bearing and the boss. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The abovementioned and other features of the inventions disclosed herein are described below with reference to the drawings of the preferred embodiments. The illustrated embodiments are intended to illustrate, but not to limit the inventions. The drawings contain the following figures. 
         FIG. 1  is a perspective view of a tractor-trailer with a cab that has a fuel system disposed behind the cab. 
         FIG. 2  is a perspective view of a fuel system mountable behind the cab of the tractor-trailer shown in  FIG. 1 , the fuel system having one or more fuel tanks disposed therein. 
         FIG. 3  is a detail view showing a mounting system for supporting neck portions of fuel tanks. 
         FIGS. 3A-3B  are schematic views of fuel tank and mounting block assemblies that can be used to support the fuel tank while excluding debris from the assemblies. 
         FIG. 4  is a perspective view illustrating an assembly including a neck boss component and a bearing assembly according to one example. 
         FIG. 5  is a perspective view of one embodiment of a bearing assembly that can be incorporated into a mounting block assembly; 
         FIG. 6  is a side view of the bearing assembly of  FIG. 5 . 
         FIG. 7  is a cross-sectional view of a bearing assembly taken at section plane  7 - 7  in  FIG. 6 . 
         FIG. 7A  is a detail view of the cross-sectional view of  FIG. 7 . 
         FIG. 8  is a schematic views of a fuel tank and mounting block assembly that can be used to support the fuel tank while excluding debris from the assembly. 
         FIG. 9  is a detail view of a portion of a modified embodiment of the fuel tank and mounting block assembly of  FIG. 8 . 
         FIG. 10  is a perspective view of an embodiment of a fuel tank and mounting block assembly that can mitigate and even exclude debris from an interface between a fuel tank boss and a bearing of a mounting block assembly. 
         FIG. 11  is a cross-sectional view of a neck mount support assembly that includes an end cap and a cover to mitigate debris ingress from the outboard and inboard sides respectively. 
         FIG. 12A  is a perspective view of an inboard side of one embodiment of a mounting block. 
         FIG. 12B  is a perspective view of an outboard side of one embodiment of a mounting block. 
         FIG. 12C  is a perspective view of an inboard side of a portion of the mounting block shown in  FIG. 12A . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     This application is directed to reducing ingress of debris, such as sand, dust and grit, into an interface that is provided between an outside surface of a neck portion of a fuel tank and a surface applying a load to the outside surface. The outside surface may be a cylindrical surface of a boss and the load applying surface may be a bearing or a component of a mounting block or mounting block assembly configured to support at least a portion of the weight of the tank. The ingress of such matter can produce wear at the neck portion of the fuel tank. Neck portion wear can lead to accelerated wear of the fuel tank or fuel system in which the tank is integrated, and/or to maintenance concerns of the fuel tank and/or fuel system. The incidence and severity of these outcomes can be reduced or eliminated by embodiments disclosed herein. 
       FIGS. 1 and 2  illustrate environments in which embodiments herein can be deployed. In one example, a fuel system  50  can be coupled with a vehicle  10  to provide the fuel needs therefor. In various embodiments, a vehicle  10  may refer to any mobile machine or device, including trailers and other towable assemblies, designed or used to transport passengers or cargo, including fuel. Examples of a vehicle may include cars, trucks, buses, trains, ships, boats, aircrafts and other types of vehicles as well as trailer and other component that can be towed by or coupled to any of the foregoing. More generally, the fuel system  50  could be part of a stationary facility for storage of fuel and/or for refueling a fleet. The vehicle  10  in  FIG. 1  is a tractor-trailer. Classes of trucks that could benefit from the disclosed improvements herein include a light duty trucks (e.g., class  1 , class  2  or class  3 ), medium duty trucks (e.g., class  4 , class  5  or class  6 ), or heavy duty trucks (e.g., class  7  or class  8 ). Passenger vehicles, including cars, wagons, vans, buses, high-occupancy vehicles could employ the disclosed improvements as well. The vehicle  10  can be any vehicle, as discussed above, but is illustrated as a tractor-trailer with a cab  18  and a detachable portion  22 , i.e., the trailer. The fuel system  50  is disposed between the cab  18  and the detachable trailer  22  but could be in other locations in other fuel systems. The connection to the vehicle  10  can be by way of mounting brackets  51  disposed on a lower portion of the fuel system  50 . The fuel system  50  can include one or a plurality of fuel tanks  52  disposed in an enclosure  53 . The fuel tanks  52  may be of any size, capacity, shape and/or weight and may be made of any suitable material. For example, the fuel tanks  52  may have a shape that is substantially cylindrical, rectangular, spherical, or the like. In addition, the fuel tank(s)  52  may be used to store any type(s) of fuel such as gaseous fuels (e.g., compressed natural gas) or a liquid (e.g., diesel). For example, gaseous fuels may include hydrogen or hydrogen based gas, hythane, H2CNG, or any other gas. The enclosure  53  can be mounted to a structure, e.g., to a support frame of the fuel system  50 . 
     In one embodiment, the fuel system  50  includes a mounting assembly  62  that can include or be supported by a frame  64 . The mounting assembly  62  can include a block member(s) that receives and retains one or more boss members of the fuel tank  52 . The mounting assembly  62  can be coupled to the mounting brackets  51 , e.g., by the first boss  54  or by other frame members between the frame  64  and the mounting brackets  51 . 
       FIGS. 3 and 3A  show details of how the fuel tank  52  can be supported by the mounting assembly  62  and/or the frame  64  and/or block members as discussed further below. The fuel tank  52  includes a first end  52 A and a second end  52 B. A cylindrical portion is disposed between the first end  52 A and the second end  52 B. The cylindrical portion can account for the majority of the volume of the fuel tank  52 . The ends of the fuel tank  52  can be enclosed by hemispherical dome members at the first end  52 A and the second end  52 B. A first boss  54  can be disposed at the first end  52 A. A second boss  58  can be disposed at the second end  52 B. Each boss can have an outer surface, e.g., the first boss  54  can have an outer surface  56  that is exposed and that is coupled to the mounting assembly  62  as discussed below. 
       FIG. 3A  schematically shows how a fixed bearing block assembly  66  can be integrated into the mounting assembly  62  to support the fuel tank  52  at the second boss  58 . The fixed bearing block assembly  66  can include a rigid block member  68 . In one embodiment the fixed bearing block assembly  66  includes a two part assembly that includes two rigid block members  68 . A first rigid block member  68  is disposed generally above the second boss  58  when applied and a second rigid block member  68  is disposed generally below the second boss  58 . The two rigid block members  68  can be identical, such that each provides one half of an inner periphery  70  configured to be disposed about the second boss  58 . In some embodiments the first and second rigid block members  68  have a “C” shape profile when separated. The “C” shape refers to one or each of the block members  68  having a convex surface, such as one-half or a portion of the inner periphery  70  and also having external sides disposed about the inner periphery  70  or portion thereof. Each block member  68  can have a first side or portion  68 A of an outer periphery thereof disposed opposite the inner periphery  70 . Each block member  68  can have a second  68 B and third side  68 C disposed opposite of each other and at opposite ends of the first side  68 A. The two rigid block members  68  can be similar or identical such that each provides a similar or identical outer periphery configured to be secured to the frame  64  or other supporting structure within the mounting brackets  51  of the fuel system  50 . Apertures in the outer periphery of the rigid block member(s)  68  can allow bolts or other fasteners to secure the two or more rigid block members  68  together. In another embodiment, the fixed bearing block assembly  66  is a single member with an aperture in a center thereof providing the inner periphery  70 . 
     The inner periphery  70  can be provided with a boss engaging feature  72 , which can be one or a plurality of inner threads  76 . The inner threads  76  can be configured to mate with the second boss  58  to limit, reduce or eliminate relative movement between the second boss  58  and the fixed bearing block assembly  66 . In one case, the second boss  58  comprises one or a plurality of outer threads  74  that can mate with the boss engaging feature  72 , e.g., with the inner threads  76 . In one case, the inner threads  76  are female threads and the outer threads  74  are male threads. In another case, the inner threads  76  are male threads and the outer threads  74  are female threads. In various embodiments, the shape and dimensions (e.g., diameter, length) of the inner periphery  70  may be configured to secure or protect the second boss  58 . For example, where the cross-section of the second boss  58  is a circle, the shape of the inner periphery  70  may also be circular. In other embodiments the cross-intersection of the second boss  58  is a rectangle and the shape of the inner periphery  70  may resemble a rectangle. 
     As noted above, the fuel tank  52  can be somewhat expanded when under pressure in part due to the materials used to form the fuel tank  52 . In some cases, a longer lasting fuel system  50  results from permitting the fuel tank  52  to expand while holding the fuel tank  52  in the fuel system  50 . In one embodiment, a first bearing block assembly  90  is provided that is configured to permit some movement between the first boss  54  and an inner periphery  96  configured to be disposed around the first boss  54 . The inner periphery  96  provides a bearing support space for supporting a bearing which actually contacts the first boss  54  as discussed further below. The first bearing block assembly  90  can be configured to be supported in the enclosure  53 , e.g., being coupled with the mounting brackets  51  directly or through the frame  64 . 
       FIG. 3A  shows that the first bearing block assembly  90  can include a first block portion  92 A and a second block portion  92 B. The block portions  92 A,  92 B can be separable in a manner similar to the rigid block member  68  of the fixed bearing block assembly  66 . The first block portion  92 A can be lifted off of the second block portion  92 B to provide access to an inner periphery  96  of the block portions  92 A,  92 B. The inner periphery  96  can be shaped and sized (e.g., diameter, length) in a variety of different ways. For instance, the inner periphery  96  can be circular, triangular, rectangular, pentagonal, hexagonal and octagonal. The inner periphery  96  can be shaped in many other configurations other than those previously listed. A bearing assembly  100  can be placed in the inner periphery  96  to provide support for the first boss  54 . In some embodiments, a second bearing assembly  100  similar to the first bearing assembly  100  can be provided on the second boss  58 . The first bearing assembly  100  can be secured in the inner periphery  96  in any suitable manner, such as by being received in a channel therein. In some embodiments, the bearing assembly  100  can be secured in place by a fastener, pin and key, latch, or other connector. In other embodiments, the bearing assembly can be secured in place through a more permanent method, such as through welding or bonding. In various embodiments, the shape and dimensions (e.g., diameter, length) of the bearing assembly  100  may be configured to secure to the inner periphery  96 . For example, where the intersection of the inner periphery  96  is a circle, the shape of the bearing assembly  100  may resemble a circle. Where the intersection of the inner periphery  96  is a rectangle, the shape of the bearing assembly  100  may resemble a rectangle. 
     This connection can be more fully appreciated with reference to  FIG. 4  in which the first bearing assembly  100  is shown positioned over the first boss  54 . The first bearing assembly  100  can be seen to have a convex outer surface  101 . The convex outer surface  101  can be convex in direction seen in a cross-section transverse, e.g., perpendicular to the opening through the first bearing assembly  100 , as shown in  FIG. 7 . The convex surface can be received in a corresponding concave channel formed in the inner periphery  96  of the first bearing block assembly  90 .  FIG. 4  shows that a first support connection  102  is provided between the outer surface  56  of the first boss  54  and a first inner portion  104  of the first bearing assembly  100 . 
       FIGS. 5-7  show the first bearing assembly  100  in more detail. The first bearing assembly  100  includes an aperture at the first inner portion  104 . The aperture is sized to receive the outer surface  56  of the first boss  54 . The aperture can allow a sliding connection to be formed in the first inner portion  104 . The first inner portion  104  can include a first tank support surface  108 . The first tank support surface  108  is configured for sliding support of the first boss  54  of the fuel tank  52  at an interface there between. The first tank support surface  108  can be a generally flat surface, e.g., forming a cylindrical portion that can be larger than the outer diameter of the outer surface  56  of the first boss  54 . The first tank support surface  108  can be smooth, with a surface roughness value of anywhere between 0.025 micrometers to 100 micrometers, including about 0.05, 0.1, 0.2, 0.4, 0.8, 1.6, 3.2, 6.3, 12.5, 25, 50, and 100 micrometers. In some embodiments, the first tank support surface  108  contains bearings, such as a sleeve bearing, ball bearings or another suitable bearing. These bearings can be arranged in a ring or sleeve pattern on the first tank support surface  108 . 
     The first tank support surface  108  can at least, in part, define a space  110  that is inward of the first tank support surface  108 . The space  110  can be disposed between the first tank support surface  108  and the outer surface  56  of the first boss  54 . The space  110  can be or can include a portion of an interface between the fuel tank  52  and the first bearing block assembly  90 . The space  110  can benefit from the addition of a mechanism to exclude dirt, debris or other matter from the interface. By excluding such matter, the first bearing block assembly  90  and the fuel system  50  can have a longer service life, particularly in dirty environments in which heavy duty vehicles are used. 
     In one embodiment, the first bearing assembly  100  includes a wiper  112 . The wiper  112  can be a first wiper  112  where the first bearing assembly  100  also includes a second wiper  130 . The first wiper  112  can be an inboard wiper, e.g., one that is positioned between the space  110  and the cylindrical portion of the fuel tank  52 . The first wiper  112  can be an outboard wiper, e.g., one that is positioned such that the block portions  92 A,  92 B are disposed between the first wiper  112  and the cylindrical portion of the fuel tank  52 . The first wiper  112  can be outboard in the sense of being more laterally located on the fuel system  50 . 
     The first wiper  112  and/or the second wiper  130  can be integrated into the first bearing assembly  100  in convenient manner such that they can be installed together with the first tank support surface  108 , which is the surface that the outer surface  56  of the first boss  54  can rest upon. In one embodiment, the first bearing assembly  100  includes a ring member  100 A that extends between the convex outer surface  101  and the first tank support surface  108 . The ring member  100 A can include a continuous monolithic structure from the convex outer surface  101  to the first tank support surface  108 . The ring member  100 A can be formed of a strong, substantially incompressible material. The ring member  100 A can include a low friction material, at least adjacent to or at the first tank support surface  108 . Some materials that can form the ring member  100 A can include, for instance, metal (e.g., aluminum or steel), metal alloy (e.g., aluminum alloys), carbon fiber reinforced plastic, or a plastic material. The ring member  100 A can be manufactured using a variety of different materials and methods. The ring member  100 A may be made by any suitable process, such as, for instance, machining, milling, water jet cutting, laser cutting, stamping, pressing, sheet metal drawing, molding (e.g., injection molding), casting, rapid prototyping using additive manufacturing techniques, or any combination thereof. The ring member  100 A can provide a first recess  116  disposed on a side surface thereof. The first recess  116  can be formed in the material of the ring member of the first bearing assembly  100  between the first tank support surface  108  and a lateral surface of the ring member  100 A. A lateral surface in this context can be disposed in a plane perpendicular to an axis A through the first bearing assembly  100 . The first recess  116  can correspond to an annular recess disposed between the material forming the first tank support surface  108  and the lateral edge of the ring member  100 A of the first bearing assembly  100 . The first wiper  112  can be installed in the first recess  116 . 
     In one embodiment, the first wiper  112  has one or more, e.g., two faces that can be secured to the first recess  116 . Any suitable approach can be provided to secure the first wiper  112  in the first recess  116 . For example, an adhesive can be used to secure a first face of the first wiper  112  to a surface of the first recess  116 . An adhesive can be used to secure a second face of the first wiper  112  to a surface of the first recess  116 . When secured in the first recess  116 , a free end of the first wiper  112  can be disposed in an opening through the first bearing assembly  100  that includes the space  110  disposed between the first tank support surface  108  and the axis A. For example, a free end of the first wiper  112  can be suspended at or adjacent to a lateral face of the ring member  100 A of the first bearing assembly  100 . The free end can comprise a free circumferential edge of the first wiper  112 . The free end of the first wiper  112  can flare at least partially into the opening within the first bearing assembly  100 . The free end of the first wiper  112  can flare toward the axis A and away from the first recess  116 . 
     In some embodiments, the first wiper  112  can be resilient in structure or material. In some embodiments, the first wiper  112  can be made from a material, including rubber, silicone, metal, cork, neoprene, nitrile rubber, fiberglass, PTFE, plastic, or any combination thereof. The first wiper  112  can be manufactured by any suitable process, such as, for instance, machining, milling, water jet cutting, laser cutting, stamping, pressing, sheet metal drawing, molding (e.g., injection molding), casting, rapid prototyping using additive manufacturing techniques, or any combination thereof. The first wiper  112  can be configured such that a portion thereof, e.g, the free end thereof, can be disposed or urged toward the axis A in at least one configuration. The first wiper  112  can include a rubber ring member  120 . The rubber material of the rubber ring member  120  can be springy or resilient such that upon being compressed the first wiper  112  applies a resisting force against the structure compressing the rubber ring member  120 . In one case, the rubber ring member  120  includes an outer periphery  122  secured in the first recess  116  and an inner periphery  124  disposed toward the axis A. The outer periphery  122  can be disposed in a free state  126 A toward the axis A by a first amount. The outer periphery  122  can be disposed in compressed state  126 B toward the axis A by a second amount. The second amount can be less than the first amount, as shown in, for example,  FIG. 7A . In some cases, the first wiper  112  is itself resilient. In other cases, a spring or other resilient member  127  can be disposed between the ring member of the first bearing assembly  100  and the first wiper  112  such that the first wiper  112  can be stiff but the resilient member  127  can act to press the first wiper  112  against the outer surface  56  of the first boss  54 . 
     As discussed above, the first bearing assembly  100  can include a second wiper  130  in some cases. If provided, the second wiper  130  can be of a similar configuration as the first wiper  112 . The second wiper  130  can be a mirror image configuration such that an outer periphery  122  thereof flares toward the axis A. The second wiper  130  can include or be configured as a rubber ring member. The material of the rubber ring member can be resilient to press against a portion of the outer surface  56  of the first boss  54  spaced away from the location of the first wiper  112 . Thus, a first bearing assembly  100  with both the first wiper  112  and the second wiper  130  can be equipped to exclude matter, e.g., dirt and grit, from the first support connection  102 , e.g., from the space  110  forming the interface between the first boss  54  and the first bearing assembly  100 . A first bearing assembly  100  with both the first wiper  112  and the second wiper  130  can be equipped to exclude matter from the contact point between the first boss  54  and the supporting structure of the fuel tank  52  within the fuel system  50 . 
     The first bearing block assembly  90  provides convenience in assembling the fuel system  50  including the first bearing block assembly  90 . For example, the separability of the first block portion  92 A from the second block portion  92 B enables the first bearing assembly  100  to be inserted into the inner periphery  96  in the space between the block portions  92 A,  92 B. When separated, the first and second block portions  92 A,  92 B have a “C” shape profile. The “C” shape refers to the first and second block portions  92 A,  92 B having a first side facing away from the inner periphery  96  with a second side and a third side disposed opposite to each other and at opposite ends of the first side, similar to the block members  68  discussed above. This structure allows the ring member of the first bearing assembly  100  to be continuous which provides a more rigid structure. A continuous solid structure ring member can be more easily handled and may be more rugged with a longer service life. 
       FIG. 3B  shows another embodiment of a bearing block assembly  190  that provides other advantages. The assembly of  FIG. 3B  can be the same as the assembly of  FIG. 3A  except as described differently below. The first bearing block assembly  190  has a monolithic block component  192 . The fuel system  50  can be formed by including the first bearing block assembly  190 , e.g., by supporting the first bearing block assembly  190  with the frame  64 . The block component  192  can include an outer periphery  194  coupled to the frame  64 . The block component  192  can include an inner periphery  196  configured to be disposed around the first boss  54 . The inner periphery  196  can be sized to surround the outer surface  56  of the first boss  54  while also providing a space for a support connection  200 . The support connection  200  can include a first inner portion  204  that can comprise an assembly. The first inner portion  204  can include a bearing assembly  197  that can include a ring member  199  that has a seam  198  that facilitates placement of the first inner portion  204  within the inner periphery  196 . The inner periphery  196  can include a concave channel that can receive a convex outer surface of the ring member  199  of the bearing assembly  197 . The convex outer surface can be similar to the convex outer surface  101  of the first bearing assembly  100 . The convex outer surface can be split at least at one location such that the ring member  199  of the bearing assembly  197  can be inserted into the inner periphery  196 . The bearing assembly  197  can include one or more of the first wiper  112  and the second wiper  130 .  FIG. 3B  shows that ring member  199  can be coupled with both the first wiper  112  and the second wiper  130 . 
     The integration of the first wiper  112  and/or the second wiper  130  into the ring member  199  of the bearing assembly  197  can be similar to that of the first bearing assembly  100 . For example, one or more of the first recess  116  and the second recess  134  can be provided in the ring member  199 . The first wiper  112  and/or the second wiper  130  can be coupled with the recesses in a suitable manner, e.g., by an adhesive connection to one or more surfaces of the recesses. 
     The first bearing block assembly  190  can be incorporated into fuel system assembly similar to the fuel system  50 . The continuous uninterrupted configuration of the block component  192  provides more rigid support for the first boss  54  in some configurations. Also, the assembly of the fuel system  50  including the first bearing block assembly  190  is simplified in not requiring the connection of two separate block components. 
     In some embodiments, the fuel system  50  includes a bellows assembly  500 . A bellows assembly  500  can include two clamps  502  and a sheath or cover  504 . The cover  504  extends from one clamp  502  to the other, forming a hollow center  506 . The clamp  502  can attach the bellows assembly  500  to the fuel tank  52  and the bearing block  66 ,  90 ,  190 . The clamps  502  attach the bellows assembly  500  to the fuel tank  52  or bearing block  66 ,  90 ,  190  by exerting a clamping force at a connecting point  508 . The connecting point  508  can be a ferrule or lip on the fuel tank  52  and/or bearing block  66 ,  90 ,  190 . In some embodiments, there is no connecting point  508  and the clamps  502  connect directly to the first or second boss  54 ,  58 . The bellows assembly  500  can simultaneously connected to two connecting points  508 , such as the connecting point  508  attached to fuel tank  52  and the connecting point  508  attached to the bearing block  66 ,  90 ,  190 . In  FIG. 8 , the cover  504  covers a section of the first boss  54  that extends between the fuel tank  52  and the bearing block  66 ,  90 ,  190 . 
     In some embodiments, the bellows assembly  500  includes two latches instead of two clamps  502 . In some embodiments, the clamps  502  are configured as ratcheting members, similar to a hose clamp. In some embodiments, the cover  504  is made from flexible material, such as natural or synthetic fabric, rubber, silicone, neoprene, nitrile rubber, PTFE, or other plastics. This flexible material allows the cover  504  to expand or contract, which thus increases or decreases the overall length of the cover  504 . In some embodiments, the cover  504  has a ribbed outer surface. The ribbed outer surface allows the hollow center  506  to maintain about a steady inner circumference while the cover  504  expands or contracts. 
     In some embodiments, the fuel system  50  can include two or more sets of bellows assemblies  500 , e.g., one for each boss  54 ,  58 . In some embodiments, the fuel system  50  can include one of bellow assembly  500  for a single boss  54 ,  58 . In some embodiments, the bellows assembly  500  is used in combination with a bearing block  66 ,  90 ,  190 . 
       FIGS. 10-12C  show another embodiment of a bearing block assembly  600  for use with the fuel system  50 . The bearing block assembly  600  can be similar to the bearing block assemblies described elsewhere herein, the disclosure of which can supplement the disclosure hereinbelow. The disclosure of the bearing block assembly  600  can supplement the other bearing block assemblies described herein. The bearing block assembly  600  can permit some movement between the first boss  54  and the bearing block assembly  600 , while also reducing the ingress of debris onto the first boss  54 . The bearing block assembly  600  can exclude ingress of debris from one or both of an outboard and an inboard side. The bearing block assembly can include an inner periphery  620 , which can be disposed around the first boss  54 . The inner periphery  620  provides a bearing support space for supporting the first bearing assembly  100 , which actually contacts the first boss  54 . As discussed above, the first bearing assembly  100  includes one or more dust wipers. In variations more or fewer wipers can be provided. In one embodiment the bearing block assembly  600  can be provided without any dust wipers in the interface between the boss  54  and the bearing surface of the assembly  100 , as shown in  FIG. 11 . The bearing block assembly  600  can be supported in the enclosure  53 . For example, the bearing block assembly  600  can be coupled with the mounting brackets  51  directly or through the frame  64 . 
     As shown in  FIGS. 10 and 11 , the bearing block assembly  600  can include a bearing block  602 .  FIGS. 12A-12C  show that the bearing block  602  can include a first block portion  602 A and a second block portion  602 B. The block portions  602 A,  602 B can be separable in a manner similar to the rigid block member  68  of the fixed bearing block assembly  66  and the first bearing block  92  of first bearing block assembly  90 . The first block portion  602 A can be lifted off of or separated from the second block portion  602 B to provide access to an inner periphery  620  of the block portions  602 A,  602 B. The inner periphery  620  can be shaped and sized (e.g., diameter, length) in a variety of different ways. For instance, the inner periphery  620  can be circular, triangular, rectangular, pentagonal, hexagonal and octagonal. The inner periphery  620  can be shaped in many other configurations other than those previously listed. A bearing assembly  100  can be placed in the inner periphery  620  to provide support for the first boss  54 . The bearing assembly  100  can be secured in the inner periphery  620  in any suitable manner, such as by being received in a channel therein. In some embodiments, the bearing assembly  100  can be secured in place by a fastener, pin and key, latch, or other connector. In other embodiments, the bearing assembly can be secured in place through a more permanent method, such as through welding or bonding. In various embodiments, the shape and dimensions (e.g., diameter, length) of the bearing assembly  100  may be configured to secure to the inner periphery  602 . For example, where the intersection of the inner periphery  620  is a circle, the shape of the bearing assembly  100  may resemble a circle. Where the intersection of the inner periphery  602  is a rectangle, the shape of the outer periphery of the bearing assembly  100  may resemble a rectangle. 
     The bearing block  602  can include a ridge  622 . The ridge  622  can be formed on one or two sides of the first block portion  602 A and the second block portion  602 B. The ridge  622  can form a raised surface on a side of the bearing block  602 . The ridge  622  can be used to connect the bearing block  602  to a structure or can be used to secure a structure to the bearing block  602 . For example, a clamp  608  can be placed around the outer edge of the ridge  622  to hold a cover  606  in place. The ridge  622  can include an annular projection on a first or inboard side of the bearing block  620 . The ridge  622  can provide a peripheral, e.g., a circumferential, surface  623  providing an area upon which a clamp can apply a compression force. Although the peripheral surface  623  is illustrated as flat, a concave recess can be provided in the peripheral surface  623  to receive or partly receive a portion of a clamp. 
     The bearing block  602  can include one or more fastener holes  626 . The fastener holes  626  can be formed on one or more sides of the first block portion  602 A and the second block portion  602 B. The fastener holes  626  can be disposed on an outboard side, as shown. In some embodiments, fastener holes  626  can be disposed on inboard and outboard sides of the bearing block portions  602 A,  602 B. In some embodiments, the fastener holes  626  are through holes that extend through the block portions  602 A,  602 B. In other embodiments, the fastener holes  626  do not extend completely through the block portions  602 A,  602 B. The fastener holes  626  can be used to connect the bearing block  602  to a structure or can be used to secure a structure to the bearing block  602 . For example, the fastener holes  626  can receive fasteners  612  to secure the end cap  604  to the bearing block  602 . The fastener holes  626  can be used to secure the cover  606  in some embodiments. 
     The bearing block  602  can include through holes  624 . The through holes  624  can be formed on one side of the first block portion  602 A and the second block portion  602 B. The through holes  624  can be used connect the bearing block  602  to a structure. For example, the through holes  624  can be used connect the bearing block  602  to the mounting brackets  51  directly or the frame  64 . 
     The bearing block  602  provides convenience in assembling the fuel system  50  including the bearing block assembly  600 . For example, the separability of the first block portion  602 A from the second block portion  602 B enables the first bearing assembly  100  to be inserted into the inner periphery  620  in the space between the block portions  602 A,  602 B. When separated, the first and second block portions  602 A,  602 B can have a “C” shape profile. The “C” shape refers to the first and second block portions  602 A,  602 B having a first side facing away from the inner periphery  620 A with a second side and a third side disposed opposite to each other and at opposite ends of the first side, similar to the block members  68  and  92  discussed above. This structure allows a ring member or other portion or all of the first bearing assembly  100  to be continuous which provides a more rigid structure. A continuous solid structure ring member can be more easily handled and may be more rugged with a longer service life. 
       FIGS. 10 and 11  show further details of the endcap  604  and the integration thereof into the bearing block assembly  600 . The end cap  604  can have a cylindrical shape with an open-ended chamber. The end cap  604  can have an opening on one side of the end cap  604  that leads to the chamber. This open-ended chamber allows for the end cap  604  to be placed around objects. For example, the end cap  604  can be placed around the first boss  54 . This open-ended chamber can have a closed end at an inside surface  607  opposite to the opening to mitigate or exclude dust or debris from entering the space in the chamber. The end cap  604  can have one or more fastener holes, which allow for the end cap  604  to connect to a structure or can be used to secure a structure to the end cap  604 . For example, the end cap  604  can be fastened to a side of the bearing block  602 . The fastener holes can be disposed on a radially outwardly extending annular flange  605 . An inboard side of the flange  605  can make contact with outside surfaces of the block portions  602 A,  602 B. 
     As shown in  FIGS. 10 and 11 , the bearing block assembly  600  can include a cover  606 . The cover  606  can be a material that can be placed over other components. In some embodiments, the cover  606  can have a hollowed center, which allows for the cover  606  to be slid over other components. For example, the cover  606  can be slid or placed over the first boss  54 . The cover  606  can be made from a flexible material, such as natural or synthetic fabric, rubber, silicone, neoprene, nitrile rubber, PTFE, or other plastics. This flexible material allows the cover  606  to expand or contract, which thus increases or decreases the overall length of the cover  606 . The cover  606  can be connected to other components through a clamp  608 . For example, the cover  606  can be connected to the bearing block  602  and the first boss  54  of the fuel tank  52  with two clamps  608 . For example, a first clamp  608  can be disposed on the bearing block  602 , e.g., by compression onto the peripheral surface  623 , and a second clamp  608  can be disposed on a surface  625  of the first boss  54 . The first and second clamps  608  can have the same configuration, e.g., similar to hose clamps in one embodiment. 
     The bearing block assembly  600  can be used to prevent the ingress of dust and other debris into the inner periphery  620  and the first boss  54 . As shown in  FIGS. 10 and 11 , the bearing block  602 , end cap  604 , and cover  606  can be used to envelop most of, or all of, the outer surface  56  of the first boss  54 . For example, the cover  606  can be used for coverage of the first boss  54  between the connecting point  508  of the fuel tank and the connecting point to bearing block  602 , while the end cap can be used to for coverage of the first boss  54  between the bearing block  602  and the end of the first boss  54 . As a result of this coverage, the bearing block assembly  600  can greatly limit the amount of debris that can enter into the inner periphery  620 . This coverage can also keep the outer surface  56  of the first boss  54  free from debris. The use of wipers  112  in the interface between the bearing block  602  and the boss  54  can further exclude debris from this interface. 
     As noted above, the bearing block assembly  600  can permit some movement between the bearing block assembly  600  and the first boss  54 . The fuel tank  52  can be somewhat expanded, e.g., elongated, when under pressure in part due to the materials used to form the fuel tank  52 . As the fuel tank  52  expands or contracts, the first bearing assembly  100  disposed within the bearing block assembly  600  can allow for first boss  54  to move relative thereto. The cover  606  can expand, e.g., elongate, or contract, e.g., foreshorten, along with the fuel tank  52 , which allows for cover  606  to maintain its coverage over the first boss  54 . The cover  606  can include a bellows-type member, as discussed above in connection with  FIGS. 8-9  or can comprise a material or structure that permits elastic expansion and/or contraction. The chamber of the endcap  604  can be sized so as to allow for the fuel tank  52  to expand without the inside surface  607  of the endcap contacting the first boss  54 . For example, the inside surface  607  of the endcap  604  can be spaced away from the end of the first boss  54  or a plug  610  enclosing an access passage in the boss  54  at or beyond the expected travel distance of the first boss  54  or plug  610 . Thus, the bearing block assembly  600  can maintain its coverage of the first boss  54  while the fuel tank  52  expands or contracts without interfering with the expected expansion and contraction of the boss  54  and/or the plug  610 . 
     While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the systems and methods described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure. Accordingly, the scope of the present inventions is defined only by reference to the appended claims. 
     Features, materials, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example are to be understood to be applicable to any other aspect, embodiment or example described in this section or elsewhere in this specification unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The protection is not restricted to the details of any foregoing embodiments. The protection extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. 
     Furthermore, certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are 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, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as a subcombination or variation of a subcombination. 
     Moreover, while operations may be depicted in the drawings or described in the specification in a particular order, such operations need not be performed in the particular order shown or in sequential order, or that all operations be performed, to achieve desirable results. Other operations that are not depicted or described can be incorporated in the example methods and processes. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations. Further, the operations may be rearranged or reordered in other implementations. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the processes illustrated and/or disclosed may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be removed, others may be added. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure. Also, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described components and systems can generally be integrated together in a single product or packaged into multiple products. 
     For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. 
     Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and/or steps are included or are to be performed in any particular embodiment. 
     Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require the presence of at least one of X, at least one of Y, and at least one of Z. 
     Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount. As another example, in certain embodiments, the terms “generally parallel” and “substantially parallel” refer to a value, amount, or characteristic that departs from exactly parallel by less than or equal to 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, or 0.1 degree. 
     The scope of the present disclosure is not intended to be limited by the specific disclosures of preferred embodiments in this section or elsewhere in this specification, and may be defined by claims as presented in this section or elsewhere in this specification or as presented in the future. The language of the claims is to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive.