Patent Publication Number: US-2006013713-A1

Title: Fuel pump

Description:
CROSS REFERENCE  
      This application claims priority to Japanese Patent application numbers 2004-205453 and 2005-41863, the contents of which are hereby incorporated by reference as if fully set forth herein.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a fuel pump for drawing a fuel such as gasoline etc., increasing the pressure thereof, and discharging this pressurized fuel.  
      2. Description of the Related Art  
       FIG. 9  shows a conventional fuel pump. In this fuel pump, a cylindrical housing  104  encloses a pump section  101  and a motor section  102 . The motor section  102  comprises an armature  106  and magnets  105 .  FIG. 10  schematically shows a cross-section of the armature  106 . The armature  106  includes a shaft  107 , a core  111  fixed to the shaft  107 , coils  119  wound around the core  111 , and a commutator  108  for supplying current to the coils  119 . A pair of bearings  110 ,  113  is disposed in the vicinity of both ends of the shaft  107 . The shaft  107  is rotatably supported by the bearings  110 ,  113 . The bottom end of the shaft  107  engages with the pump section  101 . When the shaft  107  rotates, the pump section  101  also rotates.  
       FIG. 11  shows a cross section view along the line XI-XI of  FIG. 10 . The core  111  has a plurality of slots  114  (eight slots in this case). Each coil  119  is wound around four slots  114 . In this specification, when one coil  119  which has passed a first slot returns to a (1+Y)-th slot, this will be referred to as the coil  119  having been wound around the Y slots. The coil  119  is wound around opposing slots on both sides of the shaft  107 . This is to increase the magnetic flux of the magnets  105  which pass through the coil  119  so that the magnetic energy of the magnets  105  will be effectively utilized. If the coil  119  is wound around opposing slots, the coil  119  will pass through the vicinity of the shaft  107 , and will overlap in an axial direction of the core  111  (in an axial direction of the shaft  107 ). Therefore, the coils  119  will project in the axial direction from both ends  111   a,    111   b  of the core  111 . The coil  119  which projects from both core ends  111   a,    111   b  will be in close contact with the shaft  107  which has an insulating coating on the surface.  
     SUMMARY OF THE INVENTION  
      This type of fuel pump is utilized within a fuel tank, and therefore the axial length of the fuel pump is restricted by the shape (dimension) of the fuel tank. In recent years, fuel tanks have tended to become flatter. Therefore, there is need for the axial length of the fuel pump to be shorter as well. As shown in  FIG. 10 , the conventional fuel pump has a configuration wherein the shaft  107  is provided with (listing from the top) the upper bearing  113 , the commutator  108 , the coils  119  which extend further than the core  111  in the axial direction, and the lower bearing  110 , these being provided in series. Therefore, the length L 3  between the upper bearings  113  and the lower bearing  110  must be at least equal to [the length of the upper bearing  113 +the length of the commutator  108 +the upwardly projecting length of the coils  119 +the length of the core  111 +the downwardly projecting length of the coils  119 +the length of the lower bearing  110 ].  
      The length of the fuel pump in the axial direction is affected by the length of the armature, and the length of the armature is determined by the length between the bearings  113  and  110  of the shaft  107 . For example, if it is assumed that the axial length of the bearings  113 ,  110 , the commutator  108 , and the core  111  cannot be shortened, there is no way to shorten the axial length of the fuel pump other than to shorten (the upwardly projecting length of the coils  119 ) and/or (the downwardly length of the coils  119 ). As shown in  FIG. 11 , the upwardly (or downeardly) projecting length of the coils  119  is determined by the number of windings of the coil  119  which overlap in the axial direction at the end of the core  111 . Therefore, in order to shorten the upwardly (or downwardly) projecting length of the coils  119 , the number of windings of the coils  119  must be reduced, but if the number of windings of the coils  119  is reduced, the lamination factor of the winding will drop and the pump efficiency will also be reduced.  
      Japanese Laid-Open Patent Publication No. 2002-272047 discloses technology to compress the coil ends that projects from the core using a special jig in order to shorten the projecting length of the coil in the axial direction. However, this technology is not very effective when the number of windings of the coil is low or when the diameter of the wire in the winding is small, and this technology does not fundamentally resolve the aforementioned problem. Furthermore, there is a possibility of damaging the insulating coating of the coil during compression because the coil ends are compressed by the jig.  
      It is, accordingly, one object of the present teachings to provide a fuel pump which can shorten the projecting length of the coils without reducing the number of windings of the coils, and thereby can reduce the axial length of the fuel pump.  
      In one aspect of the present teachings, fuel pump may comprise a pump section and a motor section. The motor section may include an armature having a shaft, a core fixed to the shaft, and a coils wound around the core. When the armature (i.e., the shaft) rotates, the pump section is also rotationally driven. A guide which guides the coils on the outside of the shaft is preferably provided on at least at one axial end of the core. The coils are wound between opposing slots. The coils are guided by the guide and wound so as to detour away from the region in proximity to the shaft at the end where the guide is provided. Therefore, the coils overlap in a broad area in the radial direction of the core at the end where the guide is provided. Thus, the projecting length of the coils from the end of the core can be shortened. Thereby, the length of the fuel pump in the axial direction can be shortened without reducing the number of windings of the coils (winding lamination factor). Furthermore, there is no concern of damaging the various components of the armature because operations such as compressing the part of the coils which protrudes from the end of the core will not be performed.  
      Herein, “opposing slots” does not only mean that the two slots have a positional relationship on completely opposite sides of the shaft, but may also mean that a pair of the slots are considered to be “opposing slots” even if the positional relationship is such that the inside edge of the coil is guided by a guide when the coil is wound around the pair of slots.  
      In another aspect of the present teachings, fuel pump may include a guide which is provided at a position separated only a predetermined distance toward the end of the shaft from the core. The guide restricts further protrusion of the coils toward the end of the shaft. Therefore, on the end where the guide is provided, the coils cannot be overlapped past the guide in the axial direction of the core, and thus the coils will be overlapped in the radial direction of the core. Therefore, the protrusion length of the coils from the end of the core can be shortened without reducing the number of windings (winding lamination factor) of the coils, and thereby the axial length of the fuel pump can be made shorter. Furthermore, an operation of compressing or the like of the coils which protrudes from the end of the core by a jig is not performed, so damage to the various components of the armature is not a concern.  
      In another aspect of the present teachings, fuel pump may have a guide on at lease one end of the core. The guide may include a first surface and a second surface. The first surface guides the coils on the outside of the outer surface of the shaft. The second surface is located a predetermined distance away from the core toward the end of the shaft, and restricts further protrusion of the coils toward the end of the shaft. Therefore, the coils are guided by the first surface of the guide and are wound so as to detour around the region in proximity to the shaft. Furthermore, the coils are restricted from further protruding toward the end of the shaft by the second surface of the guide. Thus, the protrusion length of the coils past the end of the core can be shortened without reducing the number of windings of the coils. Thereby, the axial length of the fuel pump can be shortened.  
      In each aspect of the aforementioned teachings, the guide are preferably formed from resin material (e.g., plastic). By forming the guides from resin material, the coils and the shaft can be insulated.  
      Furthermore, if the guide are formed from resin material, the guide and the insulating coating formed on the core are preferably integrally formed. By integrally forming the guide and the insulating coating on the shaft, the number of components can be reduced and the assembly of the fuel pump can be simplified.  
      Furthermore, with the aforementioned fuel pumps, guides are preferably provided on both ends of the core. By providing the guides on both ends the core, the fuel pump can be further shortened in the axial direction.  
      In another aspect of the present teachings, coils are wound around opposing slots. On at least one end in the axial direction of the core, the coils are preferably wound so as to detour around the region in proximity to the shaft. By winding the coils so as to detour around the region in proximity to the shaft, the winding of the coils will be broadly overlapped in the radial direction of the core. Thereby the axial length of the fuel pump can be shortened without reducing the number of windings of the coil.  
      These aspects and features may be utilized singularly or, in combination, in order to make improved fuel pump. In addition, other objects, features and advantages of the present teachings will be readily understood after reading the following detailed description together with the accompanying drawings and claims. Of course, the additional features and aspects disclosed herein also may be utilized singularly or, in combination with the above-described aspect and features. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a cross-sectional view of a fuel pump of a first representative embodiment of the present teachings.  
       FIG. 2  schematically shows a cross-sectional view of an armature of the first representative embodiment.  
       FIG. 3  is a cross-sectional view along the line III-III of  FIG. 2 .  
       FIG. 4  shows a routing of coil windings and tensile forces acting on the windings.  
       FIG. 5  schematically shows a cross-sectional view of an armature of a second representative embodiment of the present teachings.  
       FIG. 6  is a side view of an armature of a third representative embodiment of the present teachings (prior to coil winding).  
       FIG. 7  is a side view of the armature of the third representative embodiment (after coil winding).  
       FIG. 8  schematically shows the structure of the armature of another representative embodiment of the present teachings.  
       FIG. 9  is a cross-sectional view of a conventional fuel pump.  
       FIG. 10  schematically shows a cross-sectional view of a armature of the fuel pump shown in  FIG. 9 .  
       FIG. 11  is a cross-sectional view along the line XI-XI of  FIG. 10 .  
       FIG. 12  shows a routing of coil windings and tensile forces acting on the windings for a conventional fuel pump. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      A fuel pump according to a first representative embodiment of the present teachings will be explained while referring to the drawings. The fuel pump of the present embodiment is used in a motor vehicle, the fuel pump being utilized within a fuel tank and being utilized for supplying fuel to the engine of the motor vehicle. As shown in  FIG. 1 , the fuel pump comprises a pump section  10 , and a motor section  12 .  
      The pump section  10  comprises a pump cover  19 , a pump body  25 , and an impeller  26 . The pump cover  19  and the pump body  25  are formed, for instance, die casting aluminum. The pump cover  19  and the pump body  25  are fitted together to form a casing  27  wherein the impeller  26  is housed.  
      The impeller  26  is formed in substantially a disc shape by means of resin molding. Concavities  26   a  are formed at both upper and lower faces of the impeller  26 . A bottom portion of each of the upper and lower concavities  26   a  communicates via a through hole  26   c.  The concavities  26   a  form groups of concavities which extend along a circumferential direction at a position inwardly offset by a pre-determined distance from an impeller outer circumference face  26   d.  The outer circumference face  26   d  is a circular face without irregularities.  
      A fitting shaft portion  17   a —this being D-shaped in cross-section—at a lower end portion of the shaft  17  fits into a cross-sectionally D-shaped fitting hole formed in the center of the impeller  26 . Thereby, the impeller  26  is connected with the shaft  17  in a manner allowing follow-up rotation whereby slight movement in the axial direction is allowed.  
      As shown in  FIG. 1 , a groove  31  is formed in a lower face of the pump cover  19  in an are opposite the concavities  26   a  in the upper face of the impeller  26 . The groove  31  continuously extends in the direction of rotation of the impeller  26  from an upstream end to a downstream end. A discharge hole  24  is formed in the pump cover  19 , this discharge hole  24  extending from the downstream end of the groove  31  to an upper face of the pump cover  19 . The discharge hole  24  passes through from the interior to the exterior (an inner space  12   a  of the motor section  12 ) of the casing  27 .  
      An inner circumference face  19   c  of a circumference wall  19   b  of the pump cover  19  faces, along the entire circumference of this pump cover  19 , the impeller outer circumference face  26   d , with a minute clearance therebetween. For the sake of clarity, the clearance is represented as larger in the figure than it is in reality.  
      As shown in  FIG. 1 , a groove  30  is formed in an upper face of the pump body  25  in an area thereof opposite the concavities  26   a  in the lower face of the impeller  26 . The groove  30  extends continuously along the direction of rotation of the impeller  26  from an upstream end to a upstream end. An intake hole  32  is formed in the pump body  25 , this intake hole extending from a lower face of the pump body  25  to the upstream end of the groove  30 . The intake hole  32  communicates with the groove  30 . The intake hole  32  communicates between the interior and the exterior of the casing  27 .  
      The pump body  25 , this being in a superposed state with the pump cover  19 , is attached by means of caulking to a lower end portion of the housing  14 . A thrust bearing  28  is fixed to a center region of the pump body  25 . Thrust loads of the shaft  17  are received by the thrust bearing  28 .  
      In  FIG. 1 , for the sake of clarity, each clearance is represented as larger than it is in reality. The groove  30  of the pump body  25  is not directly communicated with the discharge hole  24  of the pump cover  19 . The circumference wall  19   b  of the pump cover  19  is in proximity to the outer circumference face  26   d  of the impeller  26  even at the position of the discharge hole  24 , and the groove  30  and the discharge hole  24  are essentially not connected on the outward side of the outer circumference face  26   d  of the impeller  26 . The groove  30  and the discharge hole  24  are connected by through holes  26   c  of the impeller  26 .  
      The groove  31  extending in the circumference direction of the pump cover  19 , and the groove  30  extending in the circumferential direction of the pump body  25 , extend along the direction of rotation of the impeller  26 , and extend from the intake hole  32  to the discharge hole  24 . When the impeller  26  rotates, the fuel within the fuel tank is drawn into the casing  27  via the intake hole  32 . The fuel drawn into the casing  27  flows into the groove  30 , the concavities  26   a  of the impeller  26 , and the groove. The rotation of the impeller  26  causes a revolving current of the fuel between the lower concavities  26   a  and the groove  30  and the upper concavities  26   a  and the groove. The pressure of the fuel rises as it flows along the grooves  30  and  31  from intake hole  32  to the discharge hole  24 .  
      The pressurized fuel that has flowed along the groove  31  passes through the through hole  26   c  and merges with the pressurized fuel that has flowed along the groove  31 . The fuel that has been pressurized is delivered to the motor section  12  through the discharge hole  24 . The highly pressurized fuel delivered to the motor section is further delivered to the exterior of the fuel pump from a discharge port  38 .  
      The motor section  12  is composed of a direct current motor provided with an armature  16 , a brush  13 , and permanent magnets  15  fixed within the cylindrical housing  14 . The armature  16  is provided concentrically with the magnets  15 . The brush  13  is pushed by a spring load so as to make contact with a commutator  18 . The brush  13  is connected to an external power source (not shown).  
      A lower portion of the shaft  17  of the armature  16  is rotatably supported by the bearing  20  in the pump cover  19 . An upper end of the shaft  17  is rotatably supported by the bearing  23  in the motor cover  22  which is attached to the upper end portion of the housing  14 .  
      When voltage is applied from an external power source to the brush  13 , current flows from the brush  13  to the coils  29  via the commutator  18 , causing the armature  16  to rotate. When the armature  16  rotates, the impeller  26  also rotates and fuel is drawn into the fuel pump via the intake hole  32 . The fuel which has been drawn in is pressurized by the pump section  10  as described above, and is discharged to the exterior from the discharge port  38 .  
       FIG. 2  schematically shows a cross-sectional view of the armature  16 , and  FIG. 3  shows a cross-sectional view along the line III-III of  FIG. 2 . As shown in  FIGS. 2 and 3 , the armature  16  comprises a core  21  which consists of laminated magnetic plates, guides  34  positioned on both ends of the core  21 , the coils  29  wound around slots  24  of the core  21 , the commutator  18  which supplies current to the coils  29 , and a shaft  17  which supports the core  21 , the guides  34 , and the commutator  18 . The core  21  is surrounded by the magnets  15 .  
      As shown in  FIG. 3 , the guides  34  are substantially cylindrical shaped members formed separate from the shaft  17 , and have an outside diameter larger than the shaft  17 . A through hole  34 a is formed in the center of the guide  34 . The shaft  17  is inserted through the through hole  34 a. The guide  34  may be formed integrally to the insulating coating when an insulating coating is formed on the shaft  17 .  
      The coils  29  are wound around opposing slots  24  (i.e., around  4  slots in the representative embodiment). As is clear from the drawings, the coils  29  make contact with an outside surface of the guide  34  in the region around the shaft  17 . Therefore, the coils  29  are guided to the guide  34  and wound so as to detour around the region in proximity to the shaft  17 .  
      As shown in  FIG. 2 , the lower guide  34  is also positioned on the bottom side of the core  21 . Therefore, when the coils  29  are wound around on the bottom end of the core  21  as well, the coils  29  are guided by the guide  34  and wound so as to detour around the region in proximity to the shaft  17 .  
       FIG. 4  shows a route S for the coil  29  (specifically the windings  29 a which make up the coil  29 ) to wrap around the core  21  and the direction of tensile force T which acts on the windings  29   a.    FIG. 12  shows a route S′ for a coil  119  (windings  119   a ) to wrap around the core  111  of a conventional fuel pump, and the direction of tensile force T′ which acts on the windings  119   a.    
      As shown in  FIG. 4 , the windings  29   a  are guided by the guide  34  and therefore have a route S which bulges toward the outside from the shaft  17  without passing through the region in proximity to the shaft  17 . Therefore, the tensile forces T which acts on the winding  29   a  will have a large component in the circumferential direction of the core  21 . Thereby the winding  29   a  will overlap in the radial direction of the core  21  along the wall surface  24   b  away from the center  24   a  of the slot  24 . When the winding  29   a  overlaps in the radial direction of the core  21 , the winding  29   a  is wound across a broad area of the end surface of the core  21 . Therefore, the rate of increase of the projecting length of the coils 29  with regards to the increase in the number of windings of the coils 29  can reduced.  
      On the other hand, as shown in  FIG. 12 , if the shaft  107  does not have a guide, the winding  119   a  will pass by in proximity to the shaft  107  (or in other words the route of the winding  119   a  will be route S′ in the drawing). Therefore, the tensile forces T′ which act on the winding  11   9   a  will have a large component toward the center of the core  21  (i.e., a large radial component). Therefore, the winding  119   a  will overlap from the center  114   a  of the slots  114 . If the winding  119   a  overlaps from the center  114   a  of the slots  114 , the winding  119   a  will be wound to accumulate in the area around the shaft  107  (in other words, the winding  119   a  will overlap in the axial direction of the shaft  107 ). Therefore, the rate of increase of the projecting length of the coils  119  with regards to the number of windings of the coils  119  will be large.  
      With the fuel pump of the first representative embodiment, the increase in the projecting length of the coils from the end surface of the core with regards to the increase in the number of windings of the coils  29  can be reduced by winding the coils  29  using the guides  34  attached to the shaft  17 . Therefore, the axial length of the armature  16  can be shortened without reducing the number of windings (winding lamination factor) of the coils  29 . Therefore, the axial length of the fuel pump can be shortened and the fuel pump can be made smaller and lighter.  
      Furthermore, because the fuel pump is shorter in the axial direction without reducing the number of windings of the coils  29 , the motor efficiency of the fuel pump can be maintained at a high level. That is, the rotational torque generated on the shaft  17  is determined by the current (amps) flowing to the coils  29  multiplied by the number of windings. Therefore, if the number of windings of the coils  29  is equal, the rotational torque generated by the motor section  12  will also be equal.  
      The preferred representative embodiment of the present teachings have been described above, the explanation was given using, as an example, the present teachings is not limited to this type of configuration.  
      For instance, in the above embodiment, disc shaped guides  34  were engaged to the shaft  17 , and the coil  29  was guided by the guides  34 . However, the present teachings is not restricted to this configuration, and for instance, a second representative embodiment shown in  FIG. 5  is also possible. In the second representative embodiment shown in  FIG. 5 , a wall  36  is provided around the shaft  17  on both end surfaces ( 21   a,    21   b ) of the core  21 , and the coils  29  are guided by the walls  36 . The wall  36  may be formed around the whole circumference of the shaft  17  (in other words in a cylinder around the outside of shaft  17 ), or the wall  36  may be partially formed in specific areas along the circumferential direction of the shaft  17 . By guiding the coils  29  using the walls  36 , the weight of the armature  46  can be reduced.  
      Furthermore, in the aforementioned embodiment, the coils are guided by a guide or a wall attached to the shaft, but the present teachings can be implemented without attaching a guide or wall to the shaft. For instance, a jig may be used when winding the coils around the core of the armature, and the jig removed after the coils are wound. The jig may use a cylindrical member with an inside diameter which is slightly larger than the outside diameter of the shaft, and the outside diameter of the jig may be any desired dimension. When the coils are wound, the shaft is inserted through a through hole in the jig, one end of the jig is made to contact with the end surface of the core, and the coils are wound in this condition. After winding of the coils is complete, the jig is removed. Note, after the jig is removed, the coils and the core are preferably integrated together by a plastic resin or the like in order to prevent deforming of the coils.  
      Next, a third representative embodiment of the present teachings will be described referring  FIGS. 6 and 7 . As shown in  FIGS. 6 and 7 , an armature  50  of the third representative embodiment, similar to the armature  16  of the first representative embodiment, comprises a core  56  which overlaps magnetic plates, coils  60  which is wound around slots in the core  56 , a commutator  54  which supplies current to the coils  60 , and a shaft  52  which supports the core  56  and the commutator  54 . However, the armature  50  of the third representative embodiment differs from the armature  16  of the first representative embodiment in that a disc shaped guide  58  is provided at a position a predetermined distance from an end surface  56   b  of the core  56  at an end  52   b  opposite to the commutator  54  side of the shaft  52 .  
      As shown in  FIG. 6 , the guide  58  is a disc shaped member, and is fixed to the shaft  52 . The guide  58  can be formed from plastic resin. By forming the guide  58  from plastic resin, the guide  58  will also function as an insulating coating to insulate the coils  60  and the shaft  52 . The guide  58  include an inner side portion  58   a  (or in other words, the region in proximity to the shaft  52 ) and outside portion  58   b.  The thickness of the inner side portion  58   a  is thicker than that of the outside portion  58   b.  When the guide  58  is fixed to the shaft  52 , the end surface  56   b  of the core  56  and a guide surface (i.e., surface contacting the coils  60 ) of the guide  58  will be facing each other. The distance from the end surface  56   b  of the core  56  to the guide surface of the guide  58  may be designed based upon the number of windings of the coils  60 . The guide  58  may be integrally formed with the insulating coating of the core  56 . If the guide  58  and the insulating coating of the core  56  are integrally formed, the number of components can be reduced.  
      When the coils  60  are wound around opposing slots of the core  56 , first the coil  60  is wrapped around in proximity to the shaft  52  and overlaps in the axial direction of the core  56  even on the end  56   b  where the guide  58  is provided. When the coils  60  overlaps in the axial direction of the core  56  and contacts the guide  58 , the coils  60  will not be able to further overlap in the axial direction of the core  56 . Therefore, after the coils  60  contacts the guide  58 , the coils  60  will overlap in the radial direction of the core  56 . With this embodiment, the coils  60  will efficiently overlap in the radial direction because of the thicker thickness of the inner side portion  58   a  of the guide  58 , and thereby the coils  60  will be balanced around the core  56 .  
      With the third representative embodiment, the coils  60  broadly overlap in the radial direction of the core  56 . Therefore, the projecting length that the coils  60  projects from the end surface  56   b  of the core  56  can be reduced without reducing the number of windings of the coils  60 . Thereby the axial length of the fuel pump can be shortened without reducing the motor efficiency.  
      In the third representative embodiment, the guide  58  is provided only on the end of the shaft  56  opposite to the commutator  54 , but a guide can also be provided on the commutator side of the shaft. Furthermore, the shape of the guide is not restricted to a disc shape, and any shape which restricts protrusion of the coils in the axial direction is acceptable. For instance, a guide which has a plurality of rod shaped members in a radial pattern from the shaft may be used in suitable circumferential locations to restrict protrusion of the coils in the axial direction. Furthermore, with the third representative embodiment, after winding the coils  60  around the core  56  using the guide  58 , the guide  58  may be removed. In this case, the coils  60  and the core  56  are preferably integrated using a plastic resin in order to prevent the coils from deforming after the guide  58  is removed.  
      Furthermore, a guide which provides both the function of the guide  34  of the first representative embodiments and the function of the guide  58  of the third representative embodiment may be used. For instance, as shown in  FIG. 8 , a guide  72 , which is positioned at the end of a core  80 , comprises a ring shaped portion  76  which mates with the shaft  70  and a flange portion  74  formed on the bottom end of the ring shaped portion  76 . The outer side wall of the ring shaped portion  76  guides the coils  78 , and thereby the coils  78  are wound so as to detour away from the region around the shaft  70 . Furthermore, the coils  78  contacts with the upper face of the flange portion  74 , so that overlapping of the coils  78  in the radial direction past the flange portion  74  can be restricted. Thereby, the projecting length of the coils  78  from the end of the core  80  can be shortened.  
      Finally, although the preferred representative embodiments have been described in detail, the present embodiments are for illustrative purpose only and not restrictive. It is to be understood that various changes and modifications may be made without departing from the spirit or scope of the appended claims. In addition, the additional features and aspects disclosed herein also may be utilized singularly or in combination with the above aspects and features.