Abstract:
A bearing assembly is provided having a roller bearing with two cones defining an inner raceway fitted around the journal portion of an axle. A cup defines an outer raceway that combines with the inner raceway to receive roller elements. A spacer separates the cones, and a spacer support is provided to position and support the spacer.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention relates to shaft journal bearings and, more particularly, to an improved bearing assembly spacer supporting arrangement for use in a railway freight car. 
         [0002]    Roller bearing assemblies incorporating two rows of tapered roller bearings preassembled into a self-contained, pre-lubricated package for assembly onto journals at the ends of axles or shafts are known. Such bearing assemblies are used as rail car bearings assembled onto journals at the ends of the axles. Bearings of this type typically employ two rows of tapered roller bearings fitted one into each end of a common bearing cup with their respective bearing cones having an inner diameter dimensioned to provide an interference fit with the shaft journal and with a cylindrical sleeve or spacer positioned between the cones providing accurate spacing and proper lateral clearance on the journal. Seals mounted within each end of the bearing cup provide sealing contact with wear rings bearing against the outer ends or back face of the respective bearing cones at each end of the assembly. Such seals are shown in U.S. Pat. Nos. 5,975,533, 7,607,836, and 7,534,047. 
         [0003]    In a typical rail car installation, the axle journal is machined with a fillet at the inboard end. A backing ring having a surface complementary to the contour of the fillet and an abutment surface for engaging the inboard end of an inner wear ring accurately position the bearing assembly on the journal. An end cap mounted on the end of the axle by bolts threaded into bores in the end of the axle engages the outboard wear ring and clamps the entire assembly on the end of the axle. The wear rings typically have an inner diameter dimensioned to provide interference fit with the journal over at least a portion of their length so that the entire assembly is pressed as a unit onto the end of the journal shaft portion of the axle. 
         [0004]    It is desirable to assure the support and proper spacing of the cones by assuring the support and positioning of the spacer. 
       SUMMARY OF THE INVENTION 
       [0005]    The bearing assembly of the present invention is a roller bearing that includes an inner race or cone fitted around the journal portion of the axle or shaft. The inner race formed by the cones includes an outwardly directed raceway. An outer race or cup has an inwardly directed raceway. Roller elements are located between and contacting the inner and outer raceways. 
         [0006]    A backing ring has a contoured surface complementary to and engaging the contoured surface of a fillet formed on the shaft. The fillet leads from the journal to the shoulder of the shaft. The contoured surfaces cooperate to fix the backing ring against axial movement along the shaft. 
         [0007]    The bearing assembly includes a seal assembly that provides a barrier for lubricant to be retained within the seal assembly and for contaminants to be kept out. A spacer is provided to assure the proper spacing of the two cones. A spacer support is provided to assure the proper positioning and support of the spacer during shipping and installation. The spacer support can remain in place after installation of the bearing assembly on an axle. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    In the drawings, 
           [0009]      FIG. 1  is a sectional view of a shaft journal having mounted thereon a tapered roller bearing assembly in accordance with an embodiment of the present invention; 
           [0010]      FIG. 2  is an end view of a spacer support in accordance with an embodiment of the present invention, and 
           [0011]      FIG. 3  is a detailed partial view in cross section of a tapered roller bearing spacer assembly in accordance with an embodiment of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0012]    Referring now to  FIG. 1  of the drawings, a bearing assembly indicated generally by the reference numeral  10  on  FIG. 1  is shown mounted on a journal  12  on the free, cantilevered end of a shaft or axle  14 , typically a rail car axle. Journal  12  is machined to very close tolerances and terminates at its inner end in a contoured fillet  22  leading to a cylindrical shoulder  18  of axle  14 . At the free end of the axle, journal portion  12  terminates in a slightly conical or tapered guide portion  24  dimensioned to facilitate installation of the bearing assembly onto the journal. A plurality of threaded bores  26  are formed in the end of axle  14  for receiving threaded cap screws, or bolts  28  for mounting a bearing retaining cap  30  on the end of the shaft to clamp the bearing in position as described more fully herein below. 
         [0013]    Bearing assembly  10  is preassembled before being mounted and clamped on journal  12  by retaining cap  30  and bolts  28 . The bearing assembly includes a unitary bearing cup or outer raceway  32  having a pair of inner facing raceways  34 , 36  formed one adjacent each end thereof which cooperate with a pair of bearing cones  38 , 40 , having outer facing raceways respectively, to support the two rows of tapered rollers  42 , 44 , respectively there between. A center spacer  46  is positioned between cones  38 ,  40  to maintain the cones in accurately spaced position relative to one another allowing for proper bearing lateral clearance. 
         [0014]    Spacer support  72  is seen as a generally cylindrical unitary structure usually comprised of a plastic, such as a high density polyethylene. Spacer support  72  has a radially inner edge adjacent radially outward facing outer surface  73  of spacer  46 . Spacer support  72  has a radially outer edge adjacent a radially inward facing center section  71  of cup  32 . Spacer support  72  inner edge may engage or contact radially outward facing outer surface  73  of spacer  46 . 
         [0015]    Spacer support  72  outer edge  79  may engage or contact radially inward facing counter section  71  of cup  32 . Whether or not actual contact is present, spacer support  72  acts to position and hold spacer  46  in position between cones  38  and  40  during shipping and assembly of bearing assembly  10 . Spacer support  72  may initially upon installation for shipping contact both radially inward facing center section  71  of cup  32  and radially outward facing outer surface  73  of spacer  46 , and after installation and wear in service, may contact one, both, or neither. 
         [0016]    Bearing cup  32  is provided with cylindrical counterbores  17 , 19  at its axially outer ends and a pair first end sections  48 ,  50  of seal sections  52 , 54  are pressed one into each of the cylindrical counterbores  17 , 19  in cup  32 . Each second end section  55 ,  63  of seal section  52 , 54  may include resilient sealing elements  56 ,  58  which rub upon and form a seal with radial outer surfaces  37 , 61  of a pair of seal wear rings  60 , 62  having an inwardly directed end in engagement with the outwardly directed ends of bearing cones  38 , 40  respectively. Seal section  54  is similar to seal section  52  and will not be described in detail. The other end of wear ring  60  is received in a cylindrical counterbore  64  in the axially outwardly directed end of an annular backing ring  66  which, in turn, has a counterbore  68  at its other end which is dimensioned to be received in interference and non-interference relation on the cylindrical shoulder  18  of shaft  14 . The counterbore  64  and the outer diameter of wear ring  60  are also dimensioned to provide an interference fit so that wear ring  60  is pressed into the backing ring  66  which is accurately machined to provide a contoured inner surface  70  complementary to and engaging the contour of fillet  22  when the bearing is mounted on the shaft. The outwardly directed end of wear ring  62  bears against a counterbore  31  in a retaining cap  30 . 
         [0017]    Referring now to  FIGS. 2 and 3 , detailed views of spacer support  72  are provided, along with the positioning of spacer support  72  radially between cup  32  and spacer  46 . Spacer support  72  has a radially inner edge that may include raised sections  77 . Such raised sections  77  are adjacent and possibly would engage or contact radially outward facing outer surface  73  of spacer  46 . Spacer support  72  has a radially facing outer edge  79  which is adjacent and possibly would engage or contact radially inward facing center section  71  of cup  32 .