Abstract:
A bearing ring for a radial rolling bearing, in particular for a cylindrical roller bearing or needle bearing which has, on one of the radial surface areas thereof, a track for a set of cylindrical rolling bodies which are cageless or are guided by a cage and one or two guide flanges axially bounding the track of the rolling bodies is/are fastened to the axial end surfaces of said bearing by adhesive bonding. Each guide flange has a rectangular profile cross section with a horizontal fastening limb and a vertical flange limb and, by way of the horizontal fastening limb thereof, is adhesively bonded in an encircling axial groove in an axial end surface of the bearing ring. The width of each axial groove is greater than the material thickness of each fastening limb, and each guide flange can be fixed radially in position in the particular axial groove of a profiling of the fastening limb of said guide flange, the profiling being in contact both with the outer wall and with the inner wall of the associated axial groove.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention concerns a bearing ring for a radial rolling bearing which comprises on one of its radial shell surfaces, a raceway for a set of full complement cylindrical rolling elements or cylindrical rolling elements guided by a cage, and on whose axial front end surfaces, one or two guide flanges which axially borders/border the raceway for the rolling element is/are fixed by adhesive bonding, the invention being realisable in particular and advantageously on bearing rings for cylindrical roller bearings or needle roller bearings. 
       BACKGROUND OF THE INVENTION 
       [0002]    It is common knowledge in the field of rolling bearing technology that the flanges on the bearing rings of cylindrical or needle roller bearings serve, as a rule, as an axial guidance for the rolling elements that roll on the shell surfaces of the bearing rings. Normally, these flanges are configured in one piece with the bearing rings and are made by a machining of the bearing ring. In addition, it is also well-known for a long time that flanges can be made as separate components and then fixed on the bearing ring by welding, soldering or even by adhesive bonding. 
         [0003]    A generic rolling bearing race ring with adhesively bonded guide flanges is known for example from the document DE 41 33 442 A1. In this rolling bearing race ring, the guide flanges configured with flat lateral surfaces are supported directly on the rolling bearing race ring through a collar adjoining the rolling elements, and a circular gap for receiving the adhesive adjoins the periphery of the collar turned away from the rolling elements. 
         [0004]    In a further rolling bearing ring known from the document DE 102 00 811 A1, the ring body of the bearing ring is adhesively bonded either in the region of its axial front end surfaces or in the region of its running surfaces with the respective opposing contact surfaces of two guide flanges. The front end surface or the running surface of the ring body comprises a plurality of local depressions made by displacement of material, as well as elevations surrounding these depressions, and the contact surfaces of the guide flanges bear against said elevations, so that a continuous gap for receiving an adhesive is formed between the ring body and the guide flanges. 
         [0005]    Moreover, the document DE 76 03 570 U discloses a rolling bearing race ring comprising guide flanges adhesively bonded thereon, which are fixed with the help of an intermediate adhesive foil out of dispersion hardening, cross-linking resins such as phenolic resin or melamine resin on which the ring body comprising the raceway is fixed. 
         [0006]    The main drawback of all the aforesaid known adhesively bonded joints between the guide flanges and the bearing rings is, however, that neither the bearing rings nor the guide flanges comprise any means whatever for a defined positioning of the two parts relative to each other, so that, to avoid a slipping of the guide flanges out of their exact position till the adhesive has hardened out, the guide flanges have to be fixed in position on the bearing ring by separate auxiliary devices. In addition, in the case of the first two aforesaid embodiments of adhesively bonded joints, there exists the danger of superfluous adhesive being displaced onto the raceway of the rolling elements and, in its hardened state, this adhesive obstructs a flawless functioning of the rolling bearing. 
       OBJECT OF THE INVENTION 
       [0007]    Starting from the aforesaid drawbacks of the known prior art, the object of the invention is therefore to conceive a bearing ring for a radial rolling bearing, in particular for a cylindrical roller bearing or a needle roller bearing in which the guide flanges have a defined positional fixing on the bearing ring when adhesively bonded thereto and a displacement of superfluous adhesive onto the raceway of the rolling elements is excluded. 
       DESCRIPTION OF THE INVENTION 
       [0008]    The above object is achieved according to the invention with a bearing ring made in accordance with the preamble of claim  1  by the fact that each guide flange comprises a rectangular profile cross-section with a horizontal fixing arm and a vertical flange arm, each guide flange being adhesively bonded with its horizontal fixing arm in a respective continuous axial groove in an axial front end surface of the bearing ring, the width of each axial groove being greater than the material thickness of each fixing arm and each guide flange being able to be fixed radially in position in the respective axial groove through a profiling of its fixing arm that is in contact both with the outer wall and with the inner wall of the associated axial groove. 
         [0009]    Preferred embodiments and advantageous developments of the bearing ring according to the invention will be described in the dependent claims. 
         [0010]    According to claim  2 , in the bearing ring configured according to the invention, both the fixing arm and the flange arm of each guide flange possesses the shape of a regular n-cornered polygon, each fixing arm being fixed with the polygon corners on the outer wall of the axial groove and with the centres of the polygon sides on the inner wall of the axial groove. The configuration of each guide flange as an n-cornered polygon in its overall shape has proved to be the most economical method with regard to the costs of the tools for its preferred non-machining manufacturing by deep drawing. However, it is also possible to configure the free radial edge of the flange arm as usual with a circular shape. It is likewise possible, in place of the polygonal configuration of the fixing arm to make this with a sinusoidal wavy shape so that the fixing arm can be fixed with its wave crests on the outer wall of the axial groove and with its wave troughs on the inner wall of the axial groove. 
         [0011]    According to claim  3 , a further feature of the bearing ring configured according to the invention is that the number of the polygon corners of the guide flanges can be defined as a function of their material thickness and of the size of the bearing ring as also as a function of the diameters of the outer walls and the inner walls of the axial grooves in the axial front end surfaces of the bearing ring, which diameters define the circumscribed circle and the inscribed circle of the polygon. Thus, a relatively wide axial groove and a smaller material thickness of the guide flange enable a polygonal shape with less polygon corners whereas a narrow axial groove and a larger material thickness of the guide flange necessitates an appropriate multi-cornered polygonal shape. Because a relatively wide axial groove in the axial front end surfaces of the bearing ring, however, likewise necessitates an appropriate material thickness of the bearing ring, such a groove can only be made in correspondingly large bearing rings so that, in this case, as also in most other cases, a natural lower limit is set for the minimum number of polygon corners. 
         [0012]    Moreover, according to claim  4 , the bearing ring configured according to the invention is further characterized by the fact that the continuous axial groove in one or both of the axial front end surfaces of the bearing ring has a greater depth than the length of the fixing arm of each guide flange, and each guide flange can be axially fixed in the axial groove through an abutment of its flange arm on one of the axial front end surfaces of the bearing ring. The fixing arm of each guide flange therefore protrudes freely into the respective axial groove in the front end surface of the bearing ring so that its rear-side end surface provides a further bonding surface that contributes to an enhancement of the strength of adhesive bond. In addition, an advantage of the direct abutment of the flange arm on the axial front end surface of the bearing ring consists in the fact that, given a precise manufacturing of the bearing ring width, no fluctuations whatever of the axial guide clearance for the rolling elements due to variations in the thickness of the adhesive layers, as known from the prior art, can occur anymore. 
         [0013]    Moreover, according to claim  5 , in an advantageous development of the bearing ring configured according to the invention, for supporting axial forces occurring during the operation of the bearing due to the adhesively bonded guide flanges, the fixing arm of each guide flange has a length corresponding to at least 0.125 to 0.2 times the outer diameter of the flange arm of each guide flange. Purely arithmetically, the value of the length of the fixing arm between one eighth and one fifth of the outer diameter of the flange arm has proved to be optimal for normally occurring axial forces but, in the case of higher or lower axial forces, this does not exclude, in deviation from the optimum, to make the fixing arm longer or shorter and to appropriately modify the depth of the axial groove in the front end surface of the bearing ring. 
         [0014]    Finally, as an advantageous embodiment of the bearing ring configured according to the invention, it is further proposed in claim  6  to fill all free spaces within the axial grooves in the axial front end surfaces of the bearing ring completely with an adhesive, preferably out of the group of the two-component adhesives or out of the group of the anaerobic adhesives, which adhesive is optionally mixed with a globular filling material, for example titanium oxide or aluminium powder. Two-component adhesives are characterised by good resistance against ageing and high strength at temperatures up to 100° C., whereas anaerobic, single component adhesives are suitable for use at temperatures between −60° C. and +150° C. and are characterised by freedom from solvents, adjustability of their strength and dispersion hardening properties through contact with metals in the absence of air oxygen at room temperature. 
         [0015]    To sum up, the bearing ring configured according to the invention as compared to the prior art bearing rings thus has the advantage that, through a profiling on the fixing arm and through an axial groove in the axial front end surfaces of the bearing ring, the guide flanges of the bearing ring of the invention configured with a rectangular profile cross-section can be fixed exactly in position both in radial and in axial direction relative to each other already before being adhesively bonded on the bearing ring. As a result, the guide flanges cannot slip any longer out of their exact position till the adhesive has hardened out and the additional measures in the form of separate auxiliary devices are no longer required for this purpose. Moreover, by reason of the arrangement of the axial grooves on the front end surfaces of the bearing ring, there is no longer the danger of superfluous adhesive being displaced onto the raceway of the rolling elements and of an obstruction of a flawless functioning of the rolling bearing in the hardened state of the adhesive. For the sake of completeness, it may be mentioned that the described adhesive bonding of the guide flanges configured according to the invention on the bearing ring functions even if, in place of the axial grooves in the axial front end surfaces of the bearing ring, merely two shoulders are worked into the edge of the outer shell surface of the bearing ring and quasi two axial grooves opening towards the outside are thus created. Although it is true that, in this case, the guide flanges are fixed in position through their polygonal fixing arms only on the outer diameters of these shoulders and that the number of bonding surfaces between the fixing arms and the bearing ring is thus halved, this manner of fixing has still proved to be adequate enough for the axial guidance of the rolling elements. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    One preferred form of embodiment of the bearing ring configured according to the invention will be described more closely in the following with reference to the appended drawings. The drawings show: 
           [0017]      FIG. 1 , a top view of a bearing ring configured according to the invention, with polygonal guide flanges; 
           [0018]      FIG. 2 , an enlarged representation of the section A-A according to  FIG. 1 , through the bearing ring configured according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
       [0019]      FIGS. 1 and 2  clearly disclose an outer bearing ring  1  of a radial needle roller bearing which comprises on its radially inner shell surface  3  a raceway  4  for a set of cylindrical rolling elements  6  guided through a cage  5 , and on the axial front end surfaces  7 ,  8  of which bearing ring  1  two guide flanges  9 ,  10  which axially border the raceway  4  of the rolling elements  6  are fixed through adhesive bonding. 
         [0020]    In  FIG. 2  it can be seen further that, in keeping with the invention, each guide flange  9 ,  10  has a rectangular profile cross-section made up of a horizontal fixing arm  11 ,  13  and a vertical flange arm  12 ,  14 , and that the guide flange  9 ,  10  is adhesively bonded with its horizontal fixing arm  11 ,  13  in a respective continuous axial groove  15 ,  16  in the axial front end surfaces  7 ,  8  of the bearing ring  1 . It can likewise be clearly seen that the width of each axial groove  15 ,  16  is greater than the material thickness of each fixing arm  11 ,  13  and that each guide flange  9 ,  10  is fixed radially in position in the respective axial groove  15 ,  16  through a profiling  21 ,  22  of its fixing arm  11 ,  13  shown in  FIG. 1 , which profiling  21 ,  22  is in contact both with the outer wall  17 ,  19  and with the inner wall  18 ,  20  of the associated axial groove  15 ,  16 . This profiling  15 ,  16  with which the flange arm  12 ,  14  of each guide flange  9 ,  10  is also clearly visibly configured possesses, for example, the shape of a regular  12 -cornered polygon  21 ,  22 , each fixing arm  11 ,  13  being fixed with the polygon corners  23 ,  24  on the outer wall  17 ,  19  and with the centres of the polygon sides  25 ,  26  on the inner wall  18 ,  20  of the axial groove  15 ,  16 . The number of the polygon corners  23 ,  24  of the guide flanges  9 ,  10  is however variable and depends above all on their material thickness and on the size of the bearing ring  1  as also on the diameters of the outer walls  17 ,  19  and the inner walls  18 ,  20  of the axial grooves  15 ,  16  in the front end surfaces  7 ,  8  of the bearing ring  1 , which diameters define the circumscribed circle and the inscribed circle of the polygon  21 ,  22 . 
         [0021]    Furthermore, it is disclosed in  FIG. 2  that the continuous axial grooves  15 ,  16  in the two axial front end surfaces  7 ,  8  of the bearing ring  1  have a depth that is greater than the length L of the fixing arms  11 ,  13  of the guide flanges  9 ,  10  and that the guide flanges  9 ,  10 , by the fact that their flange arms  12 ,  14  abut against the axial front end surfaces  7 ,  8  of the bearing ring  1  in the axial groove  15 ,  16 , are also fixed in axial direction. As a result, if the width of the bearing ring  1  is made with precision, no fluctuations whatever of the axial guide clearance of the rolling elements  6  can occur any longer.  FIG. 2 , as viewed in combination with  FIG. 1 , likewise shows, or at least indicates that, for supporting axial forces that occur during the operation of the bearing due to the adhesively bonded guide flanges  9 ,  10  of the fixing arms  11 ,  13 , each guide flange  9 ,  10  possesses a length L corresponding at least to 0.125 to 0.2 times the outer diameter D of the flange arm  12 ,  14  of each guide flange  9 ,  10 . 
         [0022]    From the shaded parts of  FIG. 1  and the dotted parts of  FIG. 2  it is further disclosed in the drawings that all free spaces  27 ,  28  existing within the axial grooves  15 ,  16  in the axial front end surfaces  7 ,  8  of the bearing ring  1  are completely filled with a two-component adhesive that is mixed with titanium oxide as a filling material. This adhesive is characterised by good resistance to ageing and by high strength and, for reasons of economising the costs, this adhesive is mixed with the titanium oxide in a ratio of 2 to 1. 
       LIST OF REFERENCE NUMERALS 
       [0000]    
       
           1  Bearing ring 
           2  Shell surface of  1   
           3  Shell surface of  1   
           4  Raceway for  6   
           5  Cage for  6   
           6  Rolling elements 
           7  Front end surface of  1   
           8  Front end surface of  1   
           9  Guide flange 
           10  Guide flange 
           11  Fixing arm of  9   
           12  Flange arm of  9   
           13  Fixing arm of  10   
           14  Flange arm of  10   
           15  Axial groove in  7   
           16  Axial groove in  8   
           17  Outer wall of  15   
           18  Inner wall of  15   
           19  Outer wall of  16   
           20  Inner wall of  16   
           21  Profiling/Polygon on  9   
           22  Profiling/Polygon on  10   
           23  Polygon corners of  9   
           24  Polygon corners of  10   
           25  Polygon sides of  9   
           26  Polygon sides of  10   
           27  Free spaces in  15   
           28  Free spaces in  16   
         L Length of  11 ,  13   
         D Outer diameter of  9 ,  10