Abstract:
For a flap assembly, in particular an exhaust gas flap assembly, with the flap mounted on both sides via bearing devices in the housing, the disclosure describes a design in which a bearing body is supported radially against an annular collar of the bearing device and, by way of the annular collar, is held braced in a radially spring-loaded manner in a predefined radial position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to German patent applications DE 10 2009 014 140.5 filed on Mar. 24, 2009 and PCT application PCT/EP2010/001646 filed on Mar. 16, 2010, which are hereby incorporated by reference in their entireties. 
     TECHNICAL FIELD 
     This disclosure relates to a flap arrangement, in particular an exhaust gas flap arrangement. 
     BACKGROUND 
     A flap arrangement as mentioned above is disclosed for instance in DE 37 07 904 A1. Relative to an arrangement with a flap positioned within the exhaust channel and a case-side bearing assembly positioned on one or both sides of the exhaust channel, it provides the development of a bearing assembly used to equalize temperature and manufacturing-related tolerances and deaxations for the shaft supporting the exhaust flap. For this purpose, the bearings of the shaft are rotatably arranged in at least one case-side annular collar protruding laterally relative to the exhaust channel in the direction of the shaft in at least one bearing box guided as a spherical bearing box in one part of the annular collar conically tapered toward the direction of the channel and attached axially spring-mounted in the direction of the exhaust channel. Due to the rotatable and axially displaceable guide of the shaft relative to the bearing box, the design of said bearing assembly requires a certain degree of radial play between the shaft and the cylindrical bore hole of the bearing box retaining the shaft, in particular in view of the working conditions. Said play cannot be equalized with the axial displaceability of the bearing box just as it cannot be equalized by the spherical support for the equalization of distortions and deaxations opposite the tapered part of the annular collar. In particular in connection with exhaust pulsations, this results in movements between the shaft and the bearing box, causing increased wear of the bearing as well as deflection of the bearing assembly. 
     An essentially similar situation exists with exhaust flap arrangements as they are disclosed in WO 2008/043429 A1. 
     SUMMARY 
     The object of the invention is to create an additional improved flap arrangement, in particular to design a flap arrangement as mentioned above in such a way that it is well manageable from a manufacturing-related point of view while still achieving satisfactory wear results even with large tolerances. 
     This is achieved with a flap arrangement of the kind mentioned above with the characteristics of claim  1 . The subsequent claims describe convenient updated versions. 
     The invention of a flap arrangement, in particular an exhaust flap arrangement with pulsating gas flow feed is based on the assumption that the respective gas flap is guided and supported in a case-side bearing assembly by means of a bearing box, which is supported radially flexible, in particular spring-mounted on a predefined radial position. The flexible, in particular spring-mounted bracing of the bearing box on the predefined radial position makes it possible to guide the bearing box “without play,” essentially floating, including under working conditions such as they are present for example for exhaust flaps, because the radially spring-mounted bracing at least in a radial direction achieves a flexibility in the support and guide of the bearing box with which dimensional changes due to the operation can be compensated; either with the bearing box being rotatable relative to the flap or rotating with the flap. 
     The radially flexible, in particular spring-mounted support on a predefined radial position is preferably a support on a central target position of the bearing box. According to the invention, this is in particular achieved with an annular collar of the bearing assembly, against which the bearing box is supported and springably braced on the circumference, wherein the annular collar is divided into separate annular sectors in the direction of the circumference, which are at least in part springably abutting radially against the bearing box. Within the scope of the invention, the annular collar can for instance be created with clamping claws originating from a common frame and radially springy form a retaining cage for the bearing box diagonally to their axial extension. Especially complementary, the claws can be pre-clamped to their common central position defined by the stabilized annular sector with a surrounding “spring cuff,” wherein said “cuff” is formed with one or a plurality of annular springs, preferably with a surrounding coil spring. 
     The purpose of the invention is in particular also to specify a radial position as target position for the bearing box by means of the annular cuff in such a way that at least one of the annular sectors separated in the circumferential direction which are braced together radially springy forms a radially non-flexible support for the bearing box which the supporting body is positioned on by means of the radially springy and/or spring-mounted braced sectors of the annular cuff. 
     In said solution, at least one of the annular sectors of the annular cuff is a stabilized part of the bearing assembly, against which the bearing box is supported by means of other, radially spring-mounted annular sectors. Within the scope of the invention, said spring-mounted braced annular sectors can also be formed with separate elements, which are only kept together by the radially spring-mounted retaining clamping assembly and connected to form the annular cuff with the annular sector stabilized relative to the bearing assembly. In said solution, the annular sector stabilized relative to the bearing assembly forms the radial contact for the bearing box and at the same time the guide base for the other separate annular sectors connected by means of the radial bracing appliance with the annular sector representing the base. As a result, the annular cuff can virtually “breathe,” and bulge to form the base in contrast to the stabilized annular sector within the scope of the required short regulating distances. 
     Within the scope of the invention, this is possible for both a cylindrical as well as a spherical contact area between the annular cuff and the bearing box. As a result, not only temperature-related dimensional changes can be equalized, but also manufacturing-related tolerances and axial errors within the corresponding dimensions can be adjusted. 
     It is basically within the scope of the invention that the bearing box is created as a single piece in relation to the respective gas flap. In particular with opposite positioning of the gas flap relative to the case of the flap component, the bearing box however preferably forms a rotatable component of the spherical bearing for the flap, in particular gas flap relative to the shaft of the flap. Said spherical bearing preferably comprises a spherical segment and a recess expanding toward the spherical segment and retaining the latter, wherein the spherical segment or the recess is provided on the bearing box. The spherical segment preferably forms an axially protruding part relative to the flap, in particular the gas flap, in the direction of the rotational axis, which is retained in the recess provided in the bearing box, wherein according to the invention the bearing box is axially springy braced opposite the supporting body of the bearing assembly supporting the annular cuff fixed relative to the case. This achieves a guide for the flap, in particular the gas flap that is immune against tolerances and operation-related contamination, said guide advantageously also allowing the arrangement and bracing of the shaft required to adjust the flap. 
     The result is a flap arrangement with a simple structure which is insensitive to tolerances and can be designed gas-tight, i.e., is easy to encapsulate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other details and characteristics of the invention can be gathered from the claims, the description of the drawings and the figures. In the figures: 
         FIG. 1  shows a schematic cross-section of an exhaust flap arrangement, 
         FIG. 2  shows an insulated and simplified illustration of the case-side bearing assembly in a view according to arrow II in  FIG. 1 , and 
         FIG. 3  shows a cross-section III-III of the bearing assembly according to  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     In the cross-section of an exhaust flap arrangement  1  illustrated in  FIG. 1 , the case surrounding the exhaust channel  2  is labeled with the number  3 . Exhaust channel  2  comprises flap  4  which is rotatable around an axis  5  extending across exhaust channel  2 , routed on both sides of the exhaust channel  2  in the exemplary embodiment. Of the bearing assemblies  6 ,  7  provided for this purpose, the bearing assembly  7  is penetrated by the shaft  8  connected with the flap  4  extending toward the direction of the axis  5 . The actuating drive for the flap  4  acts on said shaft in a manner not illustrated here. The shaft  8  penetrates a supporting body  13  in a passage opening  34 , preferably sealed with a seal  35  ( FIG. 2  and  FIG. 3 ). 
     Said exhaust flap arrangement  1  is preferably provided for use in exhaust systems of motors, in particular diesel motors, used for stationary applications or in motor vehicles, in particular utility vehicles, such as for example as retarding flaps in exhaust brake systems or as reversing flaps in exhaust recycling systems. 
     The case  3  comprises concentric annular flanges  10 ,  11  relative to the axis  5  for retaining the bearing assemblies  6 ,  7  arranged opposite of each other in the direction of the axis  5  and therefore diagonally, in particular perpendicular to the longitudinal axis  9  of the exhaust channel  2 . A lid-like supporting body  12 ,  13  of a bearing case is screwed down against said annular flanges on the face, said supporting body being equipped with an annular cuff  14 ,  15 , which axially latches in to the respective intake opening  16 ,  17  of the annular flange  10 ,  11  in the direction of the axis  5 . The respective annular cuff  14 ,  15  surrounds the bearing opening  18 ,  19  for a bearing box  20 ,  21  which has an open recess  22 ,  23  in the middle against the exhaust channel  2 . A spherical segment  24 ,  25  such as in the shape of a spherical section or a spherical disk connected with the flap  4  latches into said recess. The respective bearing box  20 ,  21  is flexibly braced in the direction of said spherical segment  24 ,  25 , in particular spring-loaded, wherein said spring load  26 ,  27  is created with a disk spring package in the exemplary embodiment. 
     In  FIG. 1 , only a segmented disk is provided as spherical segment  24 , which is formed in particular with the bulging of the flap  4  around the edges. The correspondingly flattened spherical segment  24  is retained in the truncated cone-shaped recess  22 . On the opposite side, the spherical segment  25  is formed as a spherical section and created by the end part of the shaft  8  allocated to flap  4  and connected to flap  4 . The recess  23  retaining said end part is dome-shaped. 
     It is apparent in particular based on  FIG. 2  and  FIG. 3  that the respective annular collar, as shown for annular collar  15 , is divided into annular sectors, three annular sectors  28  to  30  in the exemplary embodiment, of which the annular sector  28  is stabilized relative to the supporting body  13  as part of the annular collar  15  forming the bearing dish for the bearing box  21 , is in particular formed as one piece together with the supporting body  13 , while the annular sectors  29 ,  30  form parts of the bearing dish that are independent of the supporting body  13 , said parts being supportingly and radially interlocked with the annular sector  28  stabilized relative to the supporting body  13  by means of a spring arrangement  31  against the bearing box  21 . Similar to a spring cuff, the spring arrangement  31  comprises the annular sectors  28  to  30  on its outer circumference, wherein the spring arrangement  31  is defined axially relative to the annular cuff  15  in that it is positioned in an annular groove  32  of the annular cuff  15  on the circumference. 
     The exemplary embodiment illustrates a design of the spring arrangement  31  as a coil spring  33 , which is axially abutting against the flanks of the annular groove  32 , so that the annular sectors  29 ,  30  creating components that are independent and separate from the supporting body  13  of the annular cuff  15  are likewise axially fixed by means of the spring arrangement  31 . 
     This design explained with respect to the bearing assembly  7  applies analogously to the bearing assembly  6 . In both cases, the intake opening  16 ,  17  provided in the annular flange  10 ,  11  also has minor radial play for the respective annular cuff  14 ,  15 , which is irrelevant in view of the bracing of the respective bearing box  20 ,  21 , because the bearing box  20 ,  21  is braced radially play-free compared to the stabilized annular segment  28  relative to the respective supporting body  12  or  13  due to the radial restraint of the loose annular segments  29 ,  30 . 
     An embodiment according to the invention in which the flap is connected as a single part with at least one of the respective bearing boxes, in particular the bearing box  20  not penetrated by the shaft  8  with respect to the exemplary embodiment, and is consequently not rotatably supported opposite the bearing box  20 , but is in fact rotatable together with the bearing box  20 , for which the retaining annular cuff  14  subsequently forms a bearing dish divided in circumferential direction with its annular sectors, is not illustrated in the figures.