Abstract:
A radial roller bearing comprises a smooth cylindrical outer ring inserted in a housing with a roller race arranged in the outer ring. The roller race is formed by a plurality of roller-shaped rolling elements inserted in a bearing cage, which holds said rolling elements evenly spaced in a circumferential direction. The rolling elements roll off an outer raceway formed by the inner shell surface of the outer ring, and off an inner raceway formed by the outer shell surface of a shaft to be mounted, or formed by a smooth cylindrical inner ring fitted onto the shaft. The axial guidance of the roller race is accomplished by way of two separate flanged rings abutting the axial sides of the outer ring which, together with the outer ring are axially fixed in place by way of safety elements engaging with circumferential grooves in the housing. The safety elements for the flanged rings and the outer ring, and the flanged rings are fixedly connected.

Description:
This application is a National Phase of PCT Application No. EP2012/051862 filed Feb. 3, 2012, which in turn claims benefit of German Patent Application No. 10 2011 007 458.9 filed Apr. 15 2011. 
     FIELD OF THE INVENTION 
     The invention concerns a radial roller bearing, which bearing can be used particularly advantageous as a movable bearing for high radial forces and low axial forces for the mounting of shafts and rotating parts. 
     BACKGROUND OF THE INVENTION 
     It is general knowledge in the field of rolling bearings technology that shafts and rotating parts, are mostly mounted at two mounting points configured as a fixed bearing and a movable bearing because, in this way, manufacturing tolerances and length variations caused by thermal expansions between the shaft and a housing or between an axle and the rotating part can be compensated for without additional clamping forces acting on the bearing. The fixed bearing that is fixed in axial direction takes up, in addition to its radial force fraction also all axial forces in both directions, whereas the movable bearing transmits only its radial load fraction because it is not fixed in axial direction and therefore, as a result, cannot take up any axial force. The compensation of manufacturing tolerances and thermal expansions is thus effected exclusively through the movable bearing, more specifically at the two seating point of the inner ring, at the seating point of the outer ring of in the bearing itself. 
     A generic radial rolling bearing for a typical movable mounting of a radially highly loaded shaft is known, for example, from DE 2 931 348 A1. This movable bearing configured as a radial cylindrical roller bearing is made up substantially of a smooth cylindrical outer ring which is inserted into a housing and of a roller crown ring arranged in this outer ring, this crown ring being formed by a plurality of rolling elements which are inserted into a bearing cage and retained by this uniformly spaced in peripheral direction. The rolling elements configured as cylindrical rollers roll on an outer raceway formed by the inner peripheral surface of the outer ring and on an inner raceway formed by the outer peripheral surface of a smooth cylindrical inner ring which is slipped onto the shaft, which inner raceway is formed in other applications also by the outer peripheral surface of the shaft itself. In addition, for an axial guidance of the roller crown ring, two separate flanged disks are arranged on the axial sides of the outer ring, which flanged disks, together with the outer ring, are fixed in place against an axial displacement, on one side by a snap ring that engages into a circumferential groove in the housing and, on the other side by a fixing element configured as an adjustable tension ring. 
     Further, another generic radial roller bearing configured as a double row needle roller bearing for a movable mounting of a radially highly loaded rotating part is known from a catalogue of the applicant, October 2008 Edition, page 742, under the designation NAO..-ZW-ASR1. In this needle roller bearing likewise made up substantially of a smooth cylindrical inner ring that is slipped onto an axle, a roller crown ring arranged on the inner ring and a smooth cylindrical outer ring that is inserted into a rotating part, the axial guidance of the roller crown is, however, effected through two separate flanged disks that bear against the axial sides of the inner ring, which flanged disks, together with the inner ring, are fixed in place in axial direction by two fixing elements that are configured as snap rings and engage into circumferential grooves in the axle. 
     A drawback of both the aforesaid radial roller bearings is, however, that the axial fixing of the outer and the inner ring as also of the adjoining flanged disks in the housing or on the axle is effected through two additional components that, in the case of large bearing piece numbers, are delivered by the bearing manufacturer in separate magazines, in addition to the flanged disks that are likewise already delivered in a loose state. The, as it is high complexity and costs of assembly of such radial roller bearings are thus further increased by the laborious step of removing the fixing elements out of the magazine and through the necessary use of separate assembly tools for these fixing elements, so that such bearings have proved to be extremely uneconomical. 
     OBJECT OF THE INVENTION 
     Starting from the aforesaid drawbacks of the known state of the art, the object of the invention is therefore to conceive a radial roller bearing of the two initially described types, the assembly of which is simplified and possible without the use of separate assembly tools and which is therefore characterised by low assembly costs. 
     DESCRIPTION OF THE INVENTION 
     This object is achieved through a radial roller bearing with fixing elements for flanged disks and for an outer and inner ring, as well as the flanged disks configured as a fixedly connected assembly. 
     The invention is therefore based on the not very obvious perception that it is possible, through a suitable form of integration of the fixing elements with the flanged disks, to minimise on the one hand the number of components and thus the delivery quantity required for such radial roller bearing from the manufacturer and, on the other hand, at the same time, to considerably reduce the complexity and costs of assembly because the step of removing the fixing elements out of the magazine can be omitted and insertion or placement of the flanged disks into a housing or on an axle can be performed in one single work step without separate assembly tools. 
     Preferred embodiments and advantageous developments of the two types of a radial roller bearing configured according to the invention will be described herein. 
     In a first embodiment of a radial roller bearing, the fixing elements are formed by two spring rings with an elliptical shape, the transverse axes of which are smaller and the longitudinal axes of which are larger than the diameter of the flanged disks, the spring rings being fixed with their smaller diameter regions on the outer sides of the flanged disks and having an elastically inwards yielding configuration in their larger diameter regions. Thus, the elliptical spring rings are fixed with their smaller diameter regions in such a way on the flanged disks that their larger diameter regions protrude slightly beyond the flanged disks. During the assembly of the flanged disks, the spring rings are deformed by force of hand onto the diameter of the flanged disks in order to be able to insert the flanged disks into the bearing bore of the housing and to push them in this bearing bore up to the outer ring. In the end position of the flanged disks, the larger diameter regions of the snap rings then spring automatically into a circumferential groove in the housing, so that both the flanged disks as well as the outer ring of the radial roller bearing are fixed in axial direction. 
     In a further embodiment of the radial roller bearing, the fixing elements are formed respectively by two shortened semi-segments of two spring rings having an elliptical shape that are split longitudinally centrally, the transverse axes of which are smaller and the longitudinal axes of which are larger than the diameter of the flanged disks, the semi-segments being fixed respectively with their central regions on the outer sides of the flanged disks and having an elastically inwards yielding configuration in their end regions. This form of embodiment thus differs from the first form of embodiment by the fact that the elliptical spring rings are split along their longitudinal axes into two semi-segments that are slightly shortened in their respective ends but protrude slightly beyond the flanged disks with these ends. The assembly of the flanged disks configured with these fixing elements is then performed in the same manner as in the first form of embodiment till the end regions of the semi-segments yield automatically inwards into a circumferential groove in the housing. Alternatively, it would however also be possible, in place of the semi-segments of elliptical spring rings, to fix respectively two straight spring rods in such a way with their central regions on the outer sides of the flanged disks that the end regions of the spring rods protrude slightly beyond the outer diameter of the flanged disks and likewise have an elastically inwards yielding configuration. 
     In another embodiment of a radial roller bearing according to the invention,  the fixing elements are formed by two respective parallel spring wire segments arranged in a secant-like relationship to the inner diameter of the flanged disks, which spring wire segments are fixed with their ends on the outer sides of the flanged disks and are configured to yield elastically outwards in their central regions. Because the inner diameter of the flanged disks corresponds approximately to the diameter of the radial roller bearing, this means that the distance between the spring wire segments is smaller than the diameter of the axle and that through their central regions, the spring wire segments narrow the bores in the flanged disks partially. During assembly of the flanged disks, these spring wire segments are then likewise widened by force of hand to the diameter of the axle in order to be able to push the flanged disks onto the axle and to displace them on the axle up to the inner ring of the radial roller bearing. In the end position of the flanged disks, the spring wire segments then yield automatically elastically into a circumferential groove in the axle, so that both the flanged disks as well as the inner ring of the radial roller bearing are fixed in axial direction. In place of the fixing of the spring wire segments with their ends on the outer sides of the flanged disks, it is likewise conceivable to fix them only with one end on the outer sides of the radial roller bearing so as to enhance their elasticity. 
     In another embodiment of the radial roller bearing configured according to the invention, the fixing elements are formed by two respective parallel spring wire segments arranged in a secant-like relationship to the inner diameter of the flanged disks, which spring wire segments are fixed with their ends on the outer sides of the flanged disks and the central regions of the spring wire segments are cut apart and configured to yield elastically outwards. This form of embodiment differs from the aforesaid form of embodiment above all by the fact that each spring wire segment is additionally split longitudinally centrally into two semi-segments in order to enable the use of stiffer spring wire segments and to thus enhance their elasticity. The assembly of the flanged disks configured with such fixing elements is then performed in the same manner as in the aforesaid form of embodiment till the spring wire segments yield automatically inwards into a circumferential groove in the axle. 
     Finally, in a proposed feature for all the forms of embodiment of both types of radial roller bearings configured according to the invention, the fixing of the fixing elements on the outer sides of the flanged disks can be performed either by fusion of materials through welding, soldering or gluing points, or by positive engagement through stampings that are coped out of the flanged disks and surround the fixing elements. For these stampings for each fixing point, two metal strips are coped out of the flanged disks in such a way that the distance between these strips corresponds to the width of the fixing element and the strips project at a right angle from the flanged disks. The fixing element is then placed between these metal strips and, in a last step, the metal strips are bent around the fixing elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-described types of a radial rolling bearing configured according to the invention will be elucidated more closely below with reference to two preferred forms of embodiment of each type and to the appended drawings. The figures show: 
         FIG. 1 , a schematic representation of the cross-section A-A according to  FIG. 2  through a bearing arrangement showing a first type of a radial rolling bearing configured according to the invention; 
         FIG. 2 , a schematic representation of a side view of a first form of embodiment of the radial rolling bearing configured according to the invention according to  FIG. 1 ; 
         FIG. 3 , a schematic representation of a side view of a second form of embodiment of the radial rolling bearing configured according to the invention according to  FIG. 1 ; 
         FIG. 4 , a schematic representation of the cross-section B-B according to  FIG. 5  through a bearing arrangement showing a second type of a radial rolling bearing configured according to the invention; 
         FIG. 5 , a schematic representation of a side view of a first form of embodiment of the radial rolling bearing configured according to the invention according to  FIG. 4 ; 
         FIG. 6 , a schematic representation of a side view of a second form of embodiment of the radial rolling bearing configured according to the invention according to  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a schematic representation of a first type of a radial roller bearing  1  which is made up substantially out of a smooth cylindrical outer ring  3  which is inserted into a housing  2  and of a roller crown ring  4  which is arranged in this outer ring  3 . This roller crown ring  4  is formed by a plurality of roller-shaped rolling elements  6  which are inserted into a bearing cage  5  and retained uniformly spaced in peripheral direction by the cage  5 . These rolling elements  6  roll on an outer raceway  8  formed by the inner peripheral surface  7  of the outer ring  3  and on an inner raceway  12  formed by the outer peripheral surface  9  of a smooth cylindrical inner ring  11  which is slipped onto a shaft  10 . It is to be seen clearly that the axial guidance of the roller crown ring  4  is accomplished through two separate flanged disks  15 ,  16  that bear against the axial sides  13 ,  14  of the outer ring  3 , which flanged disks  15 ,  16  together with the outer ring  3  are fixed in axial direction by fixing elements  19 ,  20  which engage into circumferential grooves  17 ,  18  in the housing  2 , which fixing elements  19 ,  20  and flanged disks  15 ,  16 , are configured according to the invention as a fixedly connected assembly. 
     It can be further seen in  FIG. 2  that the fixing elements  19 ,  20  in a first form of embodiment of the radial roller bearing  1  according to the invention are formed by two spring rings  21 ,  22  of elliptical shape which are smaller along their transverse axes  23 ,  24  and larger along their longitudinal axes  25 ,  26  than the diameter of the flanged disks  15 ,  16 . The spring rings  21 ,  22  are fixed with their smaller diameter regions  21   a ,  21   b ,  22   a ,  22   b  by welding, soldering or gluing points  39 ,  40 ,  41 .  42  on the outer sides  27 ,  28  of the flanged disks  15 ,  16  and are configured in their larger diameter regions  21   c ,  21   d ,  22   c ,  22   d  which protrude slightly beyond the flanged disks to yield elastically inwards in such a way that, during assembly of the flanged disks  15 ,  16 , these regions can be deformed by force of hand onto the diameter of the flanged disks  15 ,  16  and spring in their end position automatically into the circumferential grooves  17 ,  18  in the housing  2 . 
     In contrast, in the second form of embodiment of the radial roller bearing  1  configured according to the invention illustrated in  FIG. 3 , the fixing elements  19 ,  20  are formed respectively by two shortened semi-segments  29 ,  30 ,  31 ,  32  of two elliptically shaped and longitudinally centrally split spring rings which, similar to the first form of embodiment, are smaller along their transverse axes  23 ,  24  and larger along their longitudinal axes  25 ,  26  than the diameter of the flanged disks  15 ,  16 . These semi-segments  29 ,  30 ,  31 ,  32 , too, are fixed their central regions  29   a ,  30   a ,  31   a ,  32   a  by welding, soldering or gluing points  39 ,  40 ,  41 ,  42  on the outer sides  27 ,  28  of the flanged disks  15 ,  16 , and their end regions  29   b ,  29   c ,  30   b ,  30   c ,  31   b ,  31   c ,  32   b ,  32   c  are configured to yield elastically inwards in such a way that, during assembly of the flanged disks  15 ,  16 , these regions be deformed by force of hand onto the diameter of the flanged disks  15 ,  16  and spring in their end position automatically into the circumferential grooves  17 ,  18  in the housing  2 . 
     Further,  FIG. 4  shows a schematic representation of a second type of a radial roller bearing  1 . 1  which differs from the first type through a reversal of functions and is made up substantially of a smooth cylindrical inner ring  3 . 1  which is slipped onto an axle  2 . 1  and of a roller crown ring  4 . 1  which is arranged on this inner ring  3 . 1 . This roller crown ring  4 . 1  is likewise formed by a plurality of roller-shaped rolling elements  6 . 1  which are inserted into a bearing cage  5 . 1  and retained uniformly spaced in peripheral direction by the cage  5 . 1 . These rolling elements  6 . 1  roll on an inner raceway  8 . 1  formed by the outer peripheral surface  7 . 1  of the inner ring  3 . 1  and on an outer raceway  12 . 1  formed by the inner peripheral surface  9 . 1  of a smooth cylindrical outer ring  11 . 1  which is inserted into a rotating part  10 . 1 . It is to be clearly seen that the axial guidance of the roller crown ring  4 . 1  is accomplished in this case through two separate flanged disks  15 . 1 ,  16 . 1  that bear against the axial sides  13 . 1 ,  14 . 1  of the inner ring  3 . 1  and which together with the inner ring  3 . 1  are fixed in axial direction by fixing elements  19 . 1 ,  20 . 1  which engage into circumferential grooves  17 . 1 ,  18 . 1  in the axle  2 . 1 , which fixing elements  19 . 1 ,  20 . 1  and flanged disks  15 . 1 ,  16 . 1 , are likewise configured according to the invention as a fixedly connected assembly. 
     The first form of embodiment of such a radial roller bearing  1 . 1  according to the invention shown in  FIG. 5  is characterised by the fact that the fixing elements  19 . 1 ,  20 . 1  are formed respectively by two parallel spring wire segments  33 ,  34 ,  35 ,  36  arranged in a secant-like relationship to the inner diameter of the flanged disks  15 . 1 ,  16 . 1 , which spring wire segments are fixed with their ends  33   a ,  33   b ,  34   a ,  34   b ,  35   a ,  35   b ,  36   a ,  36   b  on the outer sides  37 ,  38  of the flanged disks  15 . 1 ,  16 . 1  through stampings  43 ,  44 ,  45 ,  46  coped out of the flanged disks  15 . 1 ,  16 . 1  and are configured to yield elastically outwards in their central regions. It is to be clearly seen that the distance of the spring wire segments  33 ,  34 ,  35 ,  36  from one another is smaller than the diameter of the axle  2 . 1 , so that through their central regions  33   c ,  34   c ,  35   c ,  36   c , the spring wire segments narrow the bores in the flanged disks  15 . 1 ,  16 . 1  partially. During assembly of the flanged disks,  15 . 1 ,  16 . 1  the spring wire segments  33 ,  34 ,  35 ,  36  are then likewise widened by force of hand onto the diameter of the axle  2 . 1  and the flanged disks  15 . 1 ,  16 . 1  are slipped onto the axle  2 . 1 , so that, in their end position, the spring wire segments  33 ,  34 ,  35 ,  36  yield automatically inwards into the circumferential groove  17 . 1 ,  18 . 1  in the axle  2 . 1 . 
     Finally,  FIG. 6  further shows a second form of embodiment of a radial roller bearing  1 . 1 . configured according to the invention, in which the fixing elements  19 . 1 ,  20 . 1  are formed respectively by two parallel spring wire segments  33 ,  34 ,  35 ,  36  arranged in a secant-like relationship to the inner diameter of the flanged disks  15 . 1 ,  16 . 1 , which spring wire segments, however, are fixed with their ends  33   a ,  33   b ,  34   a ,  34   b ,  35   a ,  35   b ,  36   a ,  36   b  through welding, soldering or gluing points  39 ,  40 ,  41 ,  42  on the outer sides  37 . 1 ,  38 . 1  of the flanged disks  15 . 1 ,  16 . 1  and are additionally cut apart in their central regions  33   c ,  34   c ,  35   c ,  36   c  to enhance their elasticity. The assembly of the flanged disks  15 . 1 ,  16 . 1  configured with these fixing elements  19 . 1 ,  20 . 1  is then performed in the same manner as in the first form of embodiment till the spring wire segments  33 ,  34 ,  35 ,  36  yield automatically inwards into the circumferential groove  17 . 1 ,  17 . 2  in the axle  2 . 1 . 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 List of reference symbols 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                  1 
                 Radial roller bearing 
               
               
                   
                  1.1 
                 Radial roller bearing 
               
               
                   
                  2 
                 Housing 
               
               
                   
                  2.1 
                 Axle 
               
               
                   
                  3 
                 Outer ring of 1 
               
               
                   
                  3.1 
                 Inner ring of 1.1 
               
               
                   
                  4 
                 Roller crown ring of 1 
               
               
                   
                  4.1 
                 Roller crown ring of 1.1 
               
               
                   
                  5 
                 Bearing cage of 1 
               
               
                   
                  5.1 
                 Bearing cage of 1.1 
               
               
                   
                  6 
                 Rolling element of 1 
               
               
                   
                  6.1 
                 Rolling element of 1.1 
               
               
                   
                  7 
                 Inner peripheral surface of 3 
               
               
                   
                  7.1 
                 Outer peripheral surface of 3.1 
               
               
                   
                  8 
                 Outer raceway for 6 
               
               
                   
                  8.1 
                 Inner raceway for 6.1 
               
               
                   
                  9 
                 Outer peripheral surface of 10/11 
               
               
                   
                  9.1 
                 Inner peripheral surface of 10.1/11.1 
               
               
                   
                 10 
                 Shaft 
               
               
                   
                 10.1 
                 Rotating part 
               
               
                   
                 11 
                 Inner ring of 1 
               
               
                   
                 11.1 
                 Outer ring of 1.1 
               
               
                   
                 12 
                 Inner raceway for 6 
               
               
                   
                 12.1 
                 Outer raceway for 6.1 
               
               
                   
                 13 
                 Axial side of 3 
               
               
                   
                 13.1 
                 Axial side of 3.1 
               
               
                   
                 14 
                 Axial side of 3 
               
               
                   
                 14.1 
                 Axial side of 3.1 
               
               
                   
                 15 
                 Flanged disk on 3 
               
               
                   
                 15.1 
                 Flanged disk on 3.1 
               
               
                   
                 16 
                 Flanged disk on 3 
               
               
                   
                 16.1 
                 Flanged disk on 3.1 
               
               
                   
                 17 
                 Groove in 2 
               
               
                   
                 17.1 
                 Groove in 2.1 
               
               
                   
                 18 
                 Groove in 2 
               
               
                   
                 18.1 
                 Groove in 2.1 
               
               
                   
                 19 
                 Fixing element for 15 
               
               
                   
                 19.1 
                 Fixing element for 15.1 
               
               
                   
                 20 
                 Fixing element for 16 
               
               
                   
                 20.1 
                 Fixing element for 16.1 
               
               
                   
                 21 
                 Spring ring 
               
               
                   
                 21a 
                 Small diameter region of 21 
               
               
                   
                 21b 
                 Small diameter region of 21 
               
               
                   
                 21c 
                 Large diameter region of 21 
               
               
                   
                 21d 
                 Large diameter region of 21 
               
               
                   
                 22 
                 Spring ring 
               
               
                   
                 22a 
                 Small diameter region of 22 
               
               
                   
                 22b 
                 Small diameter region of 22 
               
               
                   
                 22c 
                 Large diameter region of 22 
               
               
                   
                 22d 
                 Large diameter region of 22 
               
               
                   
                 23 
                 Transverse axis of 21 
               
               
                   
                 24 
                 Transverse axis of 22 
               
               
                   
                 25 
                 Longitudinal axis of 21 
               
               
                   
                 26 
                 Longitudinal axis of 22 
               
               
                   
                 27 
                 Outer side of 15 
               
               
                   
                 28 
                 Outer side of 16 
               
               
                   
                 29 
                 Semi-segment 
               
               
                   
                 29a 
                 Central region of 29 
               
               
                   
                 29b 
                 End region of 29 
               
               
                   
                 29c 
                 End region of 29 
               
               
                   
                 30 
                 Semi-segment 
               
               
                   
                 30a 
                 Central region of 30 
               
               
                   
                 30b 
                 End region of 30 
               
               
                   
                 30c 
                 End region of 30 
               
               
                   
                 31 
                 Semi-segment 
               
               
                   
                 31a 
                 Central region of 31 
               
               
                   
                 31b 
                 End region of 31 
               
               
                   
                 31c 
                 End region of 31 
               
               
                   
                 32 
                 Semi-segment 
               
               
                   
                 32a 
                 Central region of 32 
               
               
                   
                 32b 
                 End region of 32 
               
               
                   
                 32c 
                 End region of 32 
               
               
                   
                 33 
                 Spring wire segment 
               
               
                   
                 33a 
                 End of 33 
               
               
                   
                 33b 
                 End of 33 
               
               
                   
                 33c 
                 Central region of 33 
               
               
                   
                 34 
                 Spring wire segment 
               
               
                   
                 34a 
                 End of 34 
               
               
                   
                 34b 
                 End of 34 
               
               
                   
                 34c 
                 Central region of 34 
               
               
                   
                 35 
                 Spring wire segment 
               
               
                   
                 35a 
                 End of 35 
               
               
                   
                 35b 
                 End of 35 
               
               
                   
                 35c 
                 Central region of 35 
               
               
                   
                 36 
                 Spring wire segment 
               
               
                   
                 36a 
                 End of 36 
               
               
                   
                 36b 
                 End of 36 
               
               
                   
                 36c 
                 Central region of 36 
               
               
                   
                 37 
                 Outer side of 15.1 
               
               
                   
                 38 
                 Outer side of 16.1 
               
               
                   
                 39 
                 Welding, soldering or gluing point 
               
               
                   
                 40 
                 Welding, soldering or gluing point 
               
               
                   
                 41 
                 Welding, soldering or gluing point 
               
               
                   
                 42 
                 Welding, soldering or gluing point 
               
               
                   
                 43 
                 Stamping 
               
               
                   
                 44 
                 Stamping 
               
               
                   
                 45 
                 Stamping 
               
               
                   
                 46 
                 Stamping