Patent Publication Number: US-2023160432-A1

Title: Flinger for a seal assembly of a wheel bearing assembly

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to seals, and more particularly to seals for wheel bearing assemblies. 
     Wheel bearing assemblies, particularly for mounting wheels to vehicles such as trucks, typically include an inner axle connected with a vehicle frame, an outer hub connectable to the wheel, and a bearing for rotatably coupling the hub with the axle. The bearings are often double-row tapered rollers disposed between the outer hub and the inner axle and enable the hub, and thereby the wheel, to rotate about a central axis extending through the fixed axle. As such bearings are generally exposed to contaminants such as brake dust, dirt, oil, metal shavings, etc., which may damage the bearings if contacting the rolling elements or the bearing raceway surfaces, one or more seals are provided adjacent to the raceways to exclude such contaminants. Such seal assemblies primarily function to retain lubricant, for example, oil, grease, etc., within the bearing. Further, when such wheel hub assemblies are used on an electric vehicle, it is particularly important to minimize friction within the hub assembly to reduce electric power consumption and prevent premature drainage of the vehicle batteries. 
     SUMMARY OF THE INVENTION 
     In one aspect, the present invention is a seal assembly for a wheel bearing assembly, the wheel bearing assembly including an inner axle with a central axis and an outer hub disposed about the inner axle and having an inner circumferential surface defining a bore. The axle extends through the bore and a plurality of rolling elements rotatably couples the hub with the axle such that the hub rotates about the axis. The seal assembly comprises an annular inner case having an axial portion disposeable about the axle and a radial portion extending radially outwardly from the axial portion. A seal is coupled with the hub and has at least one sealing lip sealingly engageable with the inner case. Further, an annular flinger has an inner radial end coupled with or integrally formed with the annular inner case and an outer radial end including an outer axial portion spaced radially inwardly from the inner circumferential surface of the hub so as to define an annular labyrinth gap. 
     In another aspect, the present invention is a wheel bearing assembly comprising an inner axle with a central axis, an outer hub disposed about the axle and having a bore, the axle extending through the bore, a plurality of rolling elements rotatably coupling the hub with the axle such that the hub rotates about the axis, and a seal assembly as described in the preceding paragraph. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The foregoing summary, as well as the detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, which are diagrammatic, embodiments that are presently preferred. It should be understood, however, that the present invention is not limited to the precise arrangements and instrumentalities shown. In the drawings: 
         FIG.  1    is an axial cross-sectional view of a wheel bearing assembly including two seal assemblies each having a flinger in accordance with a first construction; 
         FIG.  2    is a broken-away, enlarged axial cross-sectional view of an upper portion of the wheel bearing assembly, showing one seal assembly with a first construction flinger; 
         FIG.  3    is an axial cross-sectional view of the first construction flinger, shown separate from the seal assembly; 
         FIG.  4    is a broken-away, enlarged axial cross-sectional view of an upper portion of the wheel bearing assembly, showing one seal assembly with a second construction flinger; 
         FIG.  5    is an axial cross-sectional view of the second construction flinger, shown separate from the seal assembly; 
         FIG.  6    is a broken-away, enlarged axial cross-sectional view of an upper portion of the wheel bearing assembly, showing one seal assembly with a third construction flinger; 
         FIG.  7    is an axial cross-sectional view of the third construction flinger, shown separate from the seal assembly; 
         FIG.  8    is a broken-away, enlarged axial cross-sectional view of an upper portion of the wheel bearing assembly, showing one seal assembly with a fourth construction flinger; 
         FIG.  9    is a more enlarged view of a portion of  FIG.  8     
         FIG.  10    is an axial cross-sectional view of the fourth construction flinger, shown separate from the seal assembly; 
         FIG.  11    is a broken-away, enlarged axial cross-sectional view of an upper portion of the wheel bearing assembly, showing one seal assembly with a fifth construction flinger; 
         FIG.  12    is a broken-away, enlarged axial cross-sectional view of an upper portion of the wheel bearing assembly, showing one seal assembly with a sixth construction flinger; 
         FIG.  13    is an axial cross-sectional view of the sixth construction flinger, shown separate from the seal assembly; 
         FIG.  14    is a broken-away, enlarged axial cross-sectional view of an upper portion of the wheel bearing assembly, showing one seal assembly with a seventh construction flinger; and 
         FIG.  15    is an axial cross-sectional view of the seventh construction flinger, shown separate from the seal assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Certain terminology is used in the following description for convenience only and is not limiting. The words “inner”, “inwardly” and “outer”, “outwardly” refer to directions toward and away from, respectively, a designated centerline or a geometric center of an element being described, the particular meaning being readily apparent from the context of the description. Further, as used herein, the words “connected” and “coupled” are each intended to include direct connections between two members without any other members interposed therebetween and indirect connections between members in which one or more other members are interposed therebetween. The terminology includes the words specifically mentioned above, derivatives thereof, and words of similar import. 
     Referring now to the drawings in detail, wherein like numbers are used to indicate like elements throughout, there is shown in  FIGS.  1 - 15    an annular flinger  10  for a seal assembly  11  of a wheel bearing assembly  12 , preferably for an electrically powered or “electric” truck. The wheel bearing assembly  12  includes an inner axle  14  with a central axis A C , an outer hub  16  having an inner circumferential surface  17  defining a bore  21 , the axle  14  extending through the bore  21 , and a plurality of rolling elements  18  disposed between and rotatably coupling the hub  16  with the axle  14  such that the hub  16  rotates about the central axis A C . The seal assembly  11  basically comprises an annular inner case  20  disposed about the axle  14 , a seal  22  coupled with the hub  16  and having at least one sealing lip  24  sealing engaged with the inner case  20 , and the annular flinger  10 . The flinger  10  has an inner radial end  10   a  coupled with or integrally formed with the inner case  20  and an outer radial end  10   b  spaced radially inwardly from the hub  16  so as to define an outer annular labyrinth gap LG AO . 
     As best shown in  FIG.  1   , the axle  14  is fixedly connected with a vehicle frame (not shown) and has an outer circumferential surface  14   a , at least one and preferably two inner bearing rings  30  disposed about the outer surface  14   a , and at least one nut  32  securing the ring(s)  30  onto the axle  14 . Alternatively, the axle  14  may have one or more inner raceway grooves (none shown) formed directly on the hub outer surface  14   a . The hub  16  further has two opposing axial ends  16   a ,  16   b , a flange portion  16   c  and at least one and preferably two outer bearing rings  34  disposed within the bore  21 , but may alternatively have one or more outer raceway grooves formed in the inner surface  17 . The hub  16  is connected with a wheel (not shown), with a drive shaft  1  and with a steering mechanism and/or a suspension assembly (neither shown). Preferably, the wheel bearing assembly  12  includes two sets or “rows”  19 A,  19 B of the rolling elements  18  each disposed between a separate pair of aligned inner and outer rings  30 ,  34 , such that the wheel bearing assembly  12  is a “double row” bearing, as depicted in  FIG.  1   . However, the wheel bearing assembly  12  may alternatively be a single row bearing or have three or more rows of rolling elements  18  or/and disposed within grooves in the axle  14  or hub  16  (no alternatives shown). Further, the rolling elements  18  are preferably tapered rollers as shown in  FIG.  1   , but may alternatively be any other known type of rolling element, such as balls, cylindrical rollers, spherical rollers, needles, etc. 
     Furthermore, the seal assembly  11  is preferably configured to retain lubricant, such as oil, grease, etc., about the rolling elements  18  and to prevent contaminants or “substances” (e.g., water, brake dust, mud, etc.) from entering the space about the rolling elements  18 . Preferably, the wheel bearing assembly  12  includes a pair of the seal assemblies  11 , specifically a first seal assembly  13 A and a second seal assembly  13 B, each seal assembly  13 A,  13 B being disposed on a separate axial side of the one or more rows  19 A,  19 B of rolling elements  18 , as shown in  FIG.  1   . However, the wheel bearing assembly  12  may include only a single seal assembly  11 , for example if one axial end  16   a  or  16   b  of the hub  16  is enclosed by other structure or components. 
     Referring to  FIGS.  2 - 15   , with each seal assembly  11 , the annular inner case  20  includes an inner axial portion  36  disposeable about the axle  14  and a radial portion  38  extending radially outwardly from the axial portion  36 . More specifically, the case axial portion  36  has opposing first and second axial ends  36   a ,  36   b , respectively, and inner and outer circumferential surfaces  37 A,  37 B, respectively, and is preferably disposed about one of the bearing inner rings  30 . However, the case axial portion  36  may alternatively be disposed directly about the outer circumferential surface  14   a  of the axle  14  or about the nut  32  or another component disposed about the axle  14 . Further, the radial portion  38  has an inner radial end  38   a  integrally formed with the first axial end  36   a  of the case axial portion  36 , an opposing outer radial end  38   b  and opposing radial surfaces  39 A,  39 B. Preferably, the inner case  20  also includes an outer axial portion  40  extending axially from the outer radial end  38   b  of the case radial portion  38  and generally toward the seal  22 , and having first and second axial ends  40   a ,  40   b  and inner and outer circumferential surfaces  41 A,  41 B. However, the inner case  20  may be formed without an outer axial portion as depicted in  FIGS.  4  and  5   . 
     Furthermore, the seal  22  preferably includes an annular outer case  42  coupled with the hub  16  and an elastomeric sealing member  44  attached to, preferably bonded to, the outer case  42  and providing the sealing lip(s)  24 . Specifically, the outer case  42  includes an axial portion  46  with opposing first and second axial ends  46   a ,  46   b  and inner and outer circumferential surfaces  47 A,  47 B, respectively, the outer circumferential surface  47 B preferably being frictionally engaged with a section of the hub inner circumferential surface  17 . The seal outer case  42  also includes a radial portion  48  extending radially inwardly from the axial portion  46  and having an outer radial end  48   a  integrally formed with first axial end  48   a  of the case axial portion  46 , an inner radial end  48   b , and opposing axial surfaces  49 A,  49 B. In the exemplary embodiment, the sealing member  44  includes at least one and preferably two axial annular sealing lips  24  engageable with the radial surface  39 A of the inner case radial portion  38  and a radial shoulder  45  spaced outwardly from the outer circumferential surface  37 B of the inner case axial portion  36  so as to define an annular labyrinth gap SG. However, the sealing member  44  may include any number of axial sealing lips, one or more radial sealing lips (none shown) engageable with the outer circumferential surface  37 B of the inner case axial portion  36  or/and other radial or axial lips or shoulders (none shown) defining labyrinth gaps. 
     Still referring to  FIGS.  2 - 15   , the annular flinger  10  includes a central portion  50  extending radially between the inner radial end  10   a  and the outer radial end  10   b  and having inner and outer radial ends  50   a ,  50   b  and opposing first and second radial surfaces  51 A,  51 B, the first surface  51 A facing generally toward the seal  22 . The flinger central portion  50  is configured to obstruct an annular space SA defined between the hub  16  and the outer radial end  38   b  of the case radial portion  38 . In most constructions of the flinger  10  as described below, at least a section of the flinger central portion  50  is frustoconical and extends radially outwardly from the inner radial end  10   a  of the flinger  10  in a direction axially away from the seal  22 . With this structure, any substances contacting the first surface  51 A of the flinger central portion  50  will be directed axially away from the seal  22  by the frustoconical section, particularly when such substances are disposed on lower portions of the flinger  10  due to the effect of gravity. 
     Also, the flinger  10  includes an outer axial portion  52  at the outer radial end  10   b , which extends from the outer radial end  50   b  of the central portion  50  in a direction generally away from the seal  22 . The outer axial portion  52  has first and second axial ends  52   a ,  52   b , respectively, and opposing inner and outer circumferential surfaces  53 A,  53 B, respectively. The outer surface  53 B of the outer axial portion  52  is spaced radially inwardly from the inner circumferential surface  17  of the hub  16 , or a section thereof as discussed below, so as to define the outer annular labyrinth gap LG AO , which is substantially axially elongated. Further, in most constructions, the flinger  10  includes an inner axial portion  54  having opposing first and second axial ends  54   a ,  54   b  and inner and outer circumferential surfaces  55 A,  55 B. The inner axial portion  54  is either coupled with the inner axial portion  36  of the inner case  20  ( FIGS.  1 - 3   ) or with the outer axial portion  40  of the inner case  20  ( FIGS.  6 - 15   ), as discussed in detail below. However, the flinger  10  may be formed without an inner annular portion, particularly when the flinger inner end  10   a  is integrally formed with the seal inner case  20 , as depicted in  FIGS.  4  and  5   . 
     By providing both the central portion  50  obstructing the annular space SA and the outer axial portion  52  defining the elongated outer annular labyrinth gap LG AO , the flinger  10  substantially reduces the amount of space through which contaminants or other substances may enter the seal assembly  11 , thereby greatly increasing the sealing efficiency of the seal assembly  11  without increasing friction within the wheel bearing assembly  12 . Further, the flinger  10  is preferably formed as an integral or one-piece member, but may alternatively be formed of a plurality of separately formed and connected parts, and is preferably fabricated of a molded polymer, a stamped metal, or any other appropriate material. Having described the basic structure and functioning of the flinger  10  above, the various presently preferred alternative constructions of the flinger  10  are described in detail below. 
     Referring to  FIGS.  1 - 3   , in a first construction, the annular flinger  10  is configured to be mounted to the axle  14 , preferably to one of the bearing inner rings  30 , and has a central portion  50  sized to extend radially between the axle  14 , preferably from the bearing inner ring  30 , and the outer hub  16 . Specifically, the first construction flinger  10  has an inner axial portion  54  sized to fit about a portion of the axle  14 , preferably about the outer surface  30   a  of the bearing inner ring  30  as shown in  FIG.  1   . The inner axial portion  36  of the inner case  20  is mounted about the outer surface  55 B of the flinger axial portion  54 , such that the flinger axial portion  54  is sandwiched radially between the case axial portion  36  and the bearing inner ring  30  and the inner and outer surfaces  53 A,  53 B of the axial portion  54  are each preferably frictionally engaged with the ring outer surface  30   a  (or axle outer surface  14   a ) and the case axial portion inner surface  37 A, respectively. 
     Further, the central portion  50  of the first construction flinger  10  is spaced axially from the radial section  38  of the inner case  20  and includes an inner radial disc section  56  and an outer frustoconical section  58 . The radial disc section  56  extends radially outwardly from the first axial end  54   a  of the inner axial portion  54  and the frustoconical section  58  extends both radially outwardly from the inner radial section  56  and generally axially away from the seal  22 . Further, the outer axial portion  52  of the first construction flinger  10  is generally cylindrical and is preferably spaced radially inwardly from a cylindrical surface section  17   a  of the hub inner surface  17 , which is spaced radially outwardly from a remainder of the inner surface  17 , such that the outer annular labyrinth gap LG AO  is generally cylindrical. 
     In a second construction shown in  FIGS.  4  and  5   , the annular flinger  10  is integrally formed with the seal inner case  20 , such that that the case  20  and the flinger  10  are formed as a single annular body, preferably of one-piece construction. Specifically, the second construction flinger  10  does not include an inner axial portion and the inner radial end  10   a  is provided by the inner radial end  50   a  of the central portion  50 , which is integrally formed with the outer radial end  38   b  of the inner case radial portion  38 . The central portion  50  is entirely frustoconical and extends axially and radially to the outer axial portion  52  providing the flinger outer radial end  10   b . The outer axial portion  52  is cylindrical, extends axially from the outer radial end  50   b  of the central portion  50 , and is spaced radially inwardly from the hub outwardly-stepped surface section  17   a  to define a generally cylindrical outer annular labyrinth gap LG AO . 
     Referring now to  FIGS.  6  and  7   , a third construction of the flinger  10  is formed to connect with the seal inner case  20 , preferably with the case outer axial portion  40 , such that a second, inner annular labyrinth gap LG AI  is defined between the flinger inner axial portion  54  and the outer case axial portion  46 . Specifically, the third construction flinger  10  includes an inner axial portion  54  with an inner circumferential surface  55 A sized to fit about the outer circumferential surface  41 B of the case axial portion  40  and two annular shoulders  60 ,  62  extending radially inwardly from the inner circumferential surface  55 A. When the flinger axial portion  54  is disposed about the case axial portion  40 , each shoulder  60 ,  62  is disposed against a separate axial end  40   a ,  40   b , respectively, of the case outer axial portion  54 , such that the shoulders  60 ,  62  frictionally engage the axial portion ends  40   a ,  40   b  to releasably couple the flinger  10  with the inner case  20 . 
     Alternatively, the flinger inner axial portion  54  may be attached to the case axial portion  40  by adhesive bonding, by one or more fasteners, etc. In any case, the inner annular labyrinth gap LG AI  is defined between the outer circumferential surface of the flinger inner axial portion  54  and the inner circumferential surface  47 A of the outer case axial portion  46 , or more preferably a portion of the elastomeric sealing member  44  attached thereto. Further, the third construction flinger  10  includes an entirely frustoconical central portion  54  and a cylindrical outer axial portion  52  spaced radially inwardly from the radially-outwardly stepped hub surface section  17   a . 
     As shown in  FIGS.  8 - 10   , a fourth construction of the flinger  10  has an inner axial portion  54  formed generally similarly to the axial portion  54  of the third flinger construction and defining the inner annular labyrinth gap LG AI , except that the shoulders  60 ,  62  of the fourth construction are configured to “snap-fit” about the outer axial ends  40   a ,  40   b  of case outer axial portion  40 . Specifically, an outer shoulder  60  includes an annular undercut groove  60   a  such that the shoulder  60  is deflectable axially to enable the two shoulders  60 ,  62  to fit over the ends  40   a ,  40   b  of the axial portion  40 . Thereafter, the outer shoulder  60  snaps back so that radial surfaces  61 ,  63  ( FIG.  10   ) of the two shoulders  60 ,  62 , respectively, frictionally engage the first and second axial ends  40   a ,  40   b  to frictionally couple the flinger  10  with the inner case  20 . 
     Further, the central portion  50  of the fourth construction flinger  10  has generally V-shaped axial cross-sections and includes a first frustoconical section  64  and a second frustoconical section  66 . Specifically, the first frustoconical section  64  extends radially inwardly from the inner radial end  10   a  of the flinger  10 , specifically the first axial end  54   a  of the inner axial portion  54 , and the second frustoconical section  66  extends radially outwardly from the first frustoconical section  64  to the outer axial portion  52  of the flinger  10 . With this structure, an annular channel  68  is defined between the first frustoconical section  64  and the second frustoconical section  66  for collecting substances passing through the outer annular labyrinth gap LG AO . Such substances thereafter fall or flow downwardly around the channel  68  by gravity and thereafter fall outwardly from the flinger  10  on a bottom or lower end of the wheel bearing assembly  12 . Further, the outer axial portion  52  of the fourth construction flinger  10  is cylindrical and spaced radially-inwardly from the outwardly stepped surface section  17   a  of the hub inner surface  17 . 
     Referring particularly to  FIG.  11   , a fifth construction of the flinger  10  is formed substantially identically to the fourth construction flinger  10  except that the fifth construction flinger  10  further includes an annular rib  70  extending radially outwardly from the inner axial portion  54 . Specifically, the rib  70  has an inner radial end  70   a  integral with the first axial end  54   a  of the flinger inner axial portion  54  and an opposing outer radial end  70   b . The rib outer radial end  70   b  is spaced axially from the second axial end  46   b  of the seal case axial portion  46  so as to define an axial labyrinth gap LGx, which leads into the inner annular labyrinth gap LG AI . Thus, the fifth construction flinger  10  provides three labyrinth gaps LG AO , LG AX , and LG AI  for increased sealing capability of the flinger  10 . 
     In a sixth construction shown in  FIGS.  12  and  13   , the flinger  10  includes an inner axial portion  54  preferably formed identically to the axial portion  54  of the third construction and provides the inner annular labyrinth gap LG AI . The central portion  50  of the sixth construction flinger  10  is generally frustoconical and has a substantially lesser radial length or extent in comparison with the other flinger constructions. The central portion  50  is spaced axially from the second axial end  46   b  of the outer case axial portion  46 , preferably from a portion of the elastomeric sealing member  44  molded thereon, so as to define a first axial labyrinth gap LG XI . 
     Further, the outer axial portion  52  of the sixth construction flinger  10  includes a first, inner axial section  74  extending axially from the central portion  50 , a second, outer axial section  76  spaced radially outwardly from the first axial section  74 , the second outer section  76  being substantially longer than the first section  74 , and a radial section  78  extending between and connecting the first and second axial sections  74 ,  76 . The first axial section  74  is spaced radially inwardly from the hub inner surface  17  so as to define a first outer annular labyrinth gap LG O1  and the second axial section  76  is spaced radially inwardly from the outwardly stepped cylindrical surface section  17   a  of the hub inner surface  17  so as to define a second, longer outer annular labyrinth gap LG O2 . Also, the radial section  78  is spaced axially from a radial surface  17   b  extending between the hub inner surface  17  and the outwardly stepped surface section  17   a  so as to define a relatively “short” second axial labyrinth gap LG X2 . With the structure of the sixth construction flinger  10 , a relatively long, tortuous path is defined between the flinger  10  and the outer hub  16 , which includes the second outer labyrinth gap LG O2 , the second axial labyrinth gap LG X2 , the first outer labyrinth gap LG O1 , the first axial labyrinth gap LG X1  and the inner annular labyrinth gap LG AI , which substantially prevents the ingress of contaminants or other substances into the seal assembly  11  without any increase of frictional loading within the bearing assembly  12 . 
     Referring now to  FIGS.  14  and  15   , a seventh construction of the flinger  10  is formed generally similarly to the third construction flinger  10  and includes a substantially identical inner axial portion  54 . The inner axial portion  54  is coupled to the outer axial portion  40  of the inner case  20  in similar or identical manner so as to define the inner annular labyrinth gap LG AI . The central portion  50  of the seventh construction flinger  10  is frustoconical as with third construction flinger  10 , but has a lesser radial length/extent in comparison with the third construction. Further, the outer axial portion  52  has a substantial length, is frustoconical, and is spaced radially inwardly from an inner frustoconical surface section  17   c  of the outer hub inner circumferential surface  17  such that the outer annular labyrinth gap LG AO  is also frustoconical. With the frustoconical outer axial portion  52  and the frustoconical outer annular labyrinth gap LG AO , substances entering the gap LG AO  are directed axially away from the seal  22  within lower portions of the flinger  10 . 
     Although seven presently preferred constructions of the annular flinger  10  are described above and depicted in the drawing figures, the flinger  10  may be formed with any combination of the structural features of the disclosed constructions that is capable of functioning generally as described herein. That is, the scope of the present invention includes the depicted and described flinger constructions and any other flinger construction that has an inner radial end coupled with or integrally formed with the annular inner case  20  of the seal assembly  11  and an outer radial end defining a labyrinth gap with the outer hub  16 . 
     Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. 
     Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings. 
     All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter. The invention is not restricted to the above-described embodiments, and may be varied within the scope of the following claims.