Abstract:
An axial and radial combined load rolling bearing including a separately formed radial bearing ring and an axial bearing cup that are assembled together to form the combined load bearing in a simplified manner that avoids known issues with perpendicularity between the radial and axial bearing races. A method of making such a bearing is also provided.

Description:
INCORPORATION BY REFERENCE 
       [0001]    The following documents are incorporated herein by reference as if fully set forth: U.S. Provisional Patent Application No. 62/053,379, filed Sep. 22, 2014. 
     
    
     FIELD OF INVENTION 
       [0002]    This application is generally related to rolling bearings and more particularly related to combined load rolling bearings and methods of manufacture. 
       BACKGROUND 
       [0003]    Rolling bearings are widely used in various mechanical applications. Combined load rolling bearings can include separately arranged axial rollers and radial rollers which are capable of supporting both radial and axial loads from a rotating part, and are commonly used in automotive transmissions as well as other applications. 
         [0004]    In some known prior art combined load roller bearings, this requires the formation of a drawn cup with extensive press tooling in order to form radial and axial sections upon which the separate sets of bearing rollers travel. Here, it is difficult to control the perpendicularity between the radial and axial sections, resulting in edge loading of the axial rollers which can result in premature failure of the bearing due to spalling. 
         [0005]    It is desirable to simplify the manufacture of the bearing ring parts as well as to increase the bearing life of radial and axial combination bearings. 
       SUMMARY 
       [0006]    In one embodiment, a combined load rolling bearing is provided having: a radial bearing ring with a circumferentially extending race, an outwardly extending axial flange with outwardly directed anti-rotation projections, and an inwardly extending flange; and an axial bearing cup with an axial body having ring retention tabs spaced about an inner periphery located in notched sections, and an outer radial flange having radially inwardly directed cage retention tabs. The radial bearing ring is located in the axial bearing cup with the anti-rotation projections being located in the notched sections. A cage with radial rollers is located in the radial bearing ring, with the radial rollers contacting the circumferentially extending outer race. An intermediate washer that forms an axial race is located in the axial bearing cup. A second cage with axial rollers is located in the axial bearing cup, with the axial rollers contacting the intermediate washer, and the cage being retained by the radially inwardly directed cage retention tabs. 
         [0007]    In another aspect, the radial bearing ring and the axial bearing cup are pressed (stamped or deep drawn) sheet metal parts. 
         [0008]    In another preferred aspect, the axial flange of the radial bearing ring is aligned with the axial body of the axial bearing cup. Preferably, the notched sections include end walls that contact the anti-rotation projections. 
         [0009]    In another embodiment, a method of manufacturing a radial and axial combination bearing is provided, and includes the steps of: 
         [0010]    Forming a radial bearing ring having a circumferentially extending outer race, an outwardly extending axial flange with outwardly directed anti-rotation projections, and an inwardly extending flange; 
         [0011]    Forming an axial bearing cup with an axial body having ring retention tabs spaced about an inner periphery located in notched sections, and an outer radial flange having radially inwardly directed cage retention tabs; 
         [0012]    Installing the radial bearing ring into the axial bearing cup with the anti-rotation projections being located in the notched sections; 
         [0013]    Installing a cage with radial rollers in the radial bearing ring, the radial rollers contacting the circumferentially extending race; 
         [0014]    Installing an intermediate washer that forms an axial race in the axial bearing cup; and 
         [0015]    Installing a second cage with axial rollers in the axial bearing cup, the axial rollers contacting the intermediate washer, and the cage being retained by the radially inwardly directed cage retention tabs. 
         [0016]    Additional preferred arrangements of the bearing and the manufacturing method with one or more features of the invention are described below and in the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The foregoing Summary as well as the following Detailed Description will be best understood when read in conjunction with the appended drawings. In the drawings: 
           [0018]      FIG. 1  is a plan view of a combined load rolling bearing according to the invention. 
           [0019]      FIG. 2  is a cross-sectional view taken along line  2 - 2  in  FIG. 1 . 
           [0020]      FIG. 3  is an enlarged detail view taken from the area indicated in  FIG. 1  to show an anti-rotation feature of the assembled radial bearing ring and axial bearing cup. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    Certain terminology is used in the following description for convenience only and is not limiting. The words “inner,” “outer,” “inwardly,” and “outwardly” refer to directions towards and away from the parts referenced in the drawings. A reference to a list of items that are cited as “at least one of a, b, or c” (where a, b, and c represent the items being listed) means any single one of the items a, b, c or combinations thereof. The terminology includes the words specifically noted above, derivatives thereof, and words of similar import. 
         [0022]      FIGS. 1-3  show a preferred embodiment of a combined load rolling bearing  10  (“bearing  10 ”) according to the present invention. As shown in  FIG. 2 , the bearing  10  includes a radial bearing ring  12  having a circumferentially extending outer race  20  on an inner surface thereof. An outwardly extending axial flange  14  extends radially outwardly and includes radially outwardly directed anti-rotation projections  16 . Preferably there are at least two of the anti-rotation projections  16 , and more preferably at least three of the anti-rotation projections  16 . In the preferred embodiment illustrated, there are 6 of the anti-rotation projections  16  that are equally spaced in a circumferential direction. However, the spacing as well as the number of anti-rotation projections  16  can be varied. The radial bearing ring  12  also includes an inwardly extending flange  18  which serves to retain a preferably pre-assembled roller element assembly which includes a cage  24  with radial rollers  22  located in pockets of the cage  24 . The radial rollers  22  contact the outer race  20  and are used to carry radial loads. The radial rollers  22  define an inner peripheral surface that is adapted to contact a shaft or other rotating element that is being supported that includes or defines the inner race (not shown). 
         [0023]    The radial bearing ring  12  is preferably formed by pressing (stamping or deep drawing) in one piece including the outwardly extending axial flange  14 , anti-rotation projections  16 , as well as the inwardly extending flange  18 , and is preferably formed from a bearing grade steel provided as a metal sheet that is pressed into the final configuration of the radial bearing ring  12 . The cage  24  can be made of metal or a polymeric material. The rollers  22  are preferably also made of bearing grade steel. 
         [0024]    Still with reference to  FIG. 2 , an axial bearing cup  26  is shown having an axial body  28  with ring retention tabs  30  spaced about an inner periphery thereof located in notched sections  32 . The notched sections  32  include end walls  34 A,  34 B which, as shown in detail in  FIGS. 1 and 3 , contact the anti-rotation projections  16  of the radial bearing ring  12  when the radial bearing ring  12  is assembled with the axial bearing cup  26 . Here, the anti-rotation projections  16  are located in the notched sections  32  with the axial flange  14  of the radial bearing ring  12  aligned with the axial body  28  of the axial bearing cup  26 . This ensures that the radial bearing ring  12  cannot rotate relative to the axial bearing cup  26 . The axial bearing cup  26  also includes an outer radial flange  36  having radially inwardly directed cage retention tabs  38 . 
         [0025]    The axial bearing cup  26  is preferably also formed as a pressed part (by stamping or deep drawing) and formed from a sheet metal blank made from steel. The notched sections  32  as well as the ring retention tabs  30  and cage retention tabs  38  are formed during the pressing process. 
         [0026]    Referring again to  FIG. 2 , an intermediate washer  40  that forms an axial race is located in the axial bearing cup  26 . The intermediate washer is preferably made of bearing grade steel. A second cage  44  with axial rollers  42  that are designed to carry an axial load are located in the axial bearing cup  26 . The axial rollers  42  contact the intermediate washer  40 . The second cage  44  and axial rollers  42  are preferably also pre-assembled and installed as a unit in the axial bearing cup  26 . The cage  44  is retained by the radially inwardly directed cage retention tabs  38  that extend from the radial flange  36  of the axial bearing cup  26 . 
         [0027]    The second cage  44  can be made of metal or a polymeric material. The axial rollers  42  are also formed of bearing grade steel. 
         [0028]    In a preferred method of manufacturing the radial and axial combination bearing  10 , after forming the radial bearing ring  12  and the axial bearing cup  26  by pressing from a sheet metal blank, specifically a sheet metal blank made of bearing grade steel, the radial bearing ring  12  and the axial bearing cup  26  are heat treated and tempered. Optionally, a surface finish or polishing can then take place, for example by placing the heat treated and tempered parts into a vibrating bin with polishing elements, such as ceramic chips. The completed detail parts are then assembled by installing the radial bearing ring  12  into the axial bearing cup  26  with the anti-rotation projections  16  located in the notched sections  32 . The cage  24  with the radial rollers  22  is installed in the radial bearing ring  12  with the radial rollers  22  contacting the circumferentially extending outer race  20 . The intermediate washer  40  is then installed in the axial bearing cup  26  and forms the axial race. The second cage  44  with the axial rollers  42  is then installed in the axial bearing cup  26 , with the axial rollers  42  contacting the intermediate washer  40 . The cage  44  is retained by the radially inwardly directed cage retention tabs  38  formed in the axial bearing cup  26 . 
         [0029]    Using this arrangement, the issues with the known prior art single piece bearing cups that include both the radial and axial races which are difficult to maintain perpendicular to one another during the formation process is avoided. Additionally, the tooling required for pressing both the radial bearing ring  12  and the axial bearing cup  26  is significantly less complicated than the tooling required for production of a single piece part. Thus, the bearing  10  according to the invention provides an arrangement that requires less re-work and results in less defects during manufacture. 
         [0030]    Having thus described various embodiments of the present combined load rolling bearing in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description above, could be made in the apparatus without altering the inventive concepts and principles embodied therein. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore to be embraced therein. 
       LIST OF REFERENCE NUMBERS 
       [0000]    
       
         
           
               10  Combined Load Rolling Bearing 
               12  Radial Bearing Ring 
               14  Outwardly Extending Axial Flange 
               16  Anti-rotation Projections 
               18  Inwardly extending flange 
               20  Outer Race 
               22  Radial rollers 
               24  Cage 
               26  Axial Bearing Cup 
               28  Axial body 
               30  Ring Retention Tab 
               32  Notched Sections 
               34 A, B End wall of Notched Sections 
               36  Radial Flange 
               38  Cage Retention Tab 
               40  Intermediate Washer 
               42  Axial Rollers 
               44  Cage