Abstract:
A fastening assembly for fastening a camshaft adjuster to a camshaft, having an input part that can be brought into driving engagement with a crankshaft, an output part that is non-rotationally connected to the camshaft, the output part being mounted rotationally adjustably with respect to the input part, and a control mechanism, by which a rotational angle position between the input and output parts can be adjusted. The output part is provided with a central axial opening penetrated by an end section of the camshaft. The end section has a thread-bearing thread section, which is screwed together with a tension nut acting on the output part such that the output part and the camshaft are axially loaded for the non-rotational connection thereof. To this end, the tension nut is elastically loaded in the axial direction or relieved in the axial direction.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention lies in the technical field of internal combustion engines and relates to a fastening arrangement for fastening a camshaft adjuster to a camshaft. The camshaft adjuster comprises a drive part that can be brought into drive connection with a crankshaft, a driven part that can be locked in rotation with the camshaft and is supported so that it can rotate relative to the drive part, and also an actuating mechanism that can adjust a rotational angle position between the drive part and the driven part. The driven part is locked in rotation with the camshaft by a central threaded connection. 
       BACKGROUND 
       [0002]    In internal combustion engines with mechanical valve control, gas exchange valves are actuated by cams of a camshaft-driven camshaft, wherein the control times of the valves can be determined by the arrangement and shape of the cams. Changing the rotational angle position (phase position) between the crankshaft and camshaft can influence the control times of the valves, wherein advantageous effects, such as reducing fuel consumption and pollutant generation can be achieved. For a long time, the use of special devices has been known for adjusting the phase position between the crankshaft and camshaft, wherein these devices have usually been designated “camshaft adjusters.” 
         [0003]    In general, camshaft adjusters comprise a drive part in drive connection with the crankshaft and a camshaft-fixed driven part, as well as an adjustment mechanism that is connected between the drive part and driven part for the transfer the torque from the drive part to the driven part and enables adjustment and fixing of the phase position between these two parts. In the case of a hydraulic adjustment mechanism, at least one pair of counteracting pressure chambers is provided between the drive part and driven part and this pair of chambers can be selectively charged with pressurized medium, in order to rotate the drive part and driven part relative to each other and to cause a change in the phase position between the crankshaft and camshaft. Hydraulic camshaft adjusters are described in detail, for example, in publications DE 202005008264 U1, EP 1596040 A2, DE 102005013141 A1, DE 19908934 A1, and WO 2006/039966 of the applicant. 
         [0004]    Hydraulic adjustment mechanisms conventionally comprise an electronic control device that regulates the feed and discharge of pressurized medium by means of an electromagnetically activated control valve on the basis of the current operating state of the internal combustion engine. Typically, the control valves comprise a cylindrical valve housing and a control piston that can be displaced axially in the interior of the valve housing and can be displaced by an electromagnetically moveable push rod against the spring force of a restoring spring element. Such control valves are well known as such and are described in detail, for example, in the German Patent DE 19727180 C2, the German Patent DE 19616973 C2, and also the European Patent Application EP 1 596 041 A2 of the applicant. 
         [0005]    In one common design, the driven part of the camshaft adjuster is provided with a central axial opening that is penetrated by a central screw that is screwed into an end-side threaded opening of the camshaft. The driven part and the camshaft are connected to each other in a non-positive manner (rotationally locked) by the central screw. Such a fastening of the camshaft adjuster on the camshaft is shown, for example, in the German Laid Open Patent Application DE 102004038681 A1. 
         [0006]    As is known to someone skilled in the art, it is typical for hydraulic camshaft adjusters that the valve housing of the control valve also takes over the function of the central screw, so that the driven part is locked in rotation with the camshaft by the control valve. 
         [0007]    From DE 19955507 C2, an alternative fastening of the camshaft adjuster by a central screw connection to the camshaft is further known in which a clamping nut is screwed on a screw shaft connected to the camshaft, wherein the driven part of the camshaft adjuster is clamped axially with a flange part of the screw shaft. 
       SUMMARY 
       [0008]    Accordingly, the objective of the present invention consists in providing the ability to fasten the camshaft adjust using a central screw connection to the camshaft, wherein the invention advantageously refines the known central screw connections. 
         [0009]    This and other objectives are met according to the proposal of the invention by a fastening arrangement for fastening a camshaft adjuster to a camshaft with the features of the independent claim. Advantageous constructions of the invention are given by the features of the subordinate claims. 
         [0010]    According to the invention, a fastening arrangement is shown for fastening a camshaft adjuster by a central screw connection to a camshaft. The fastening arrangement comprises a camshaft adjuster with a drive part that can be brought into drive connection with a crankshaft, a driven part that is locked in rotation with the camshaft and is supported so that it can rotate relative to the drive part, as well as an especially hydraulic adjustment mechanism through which a rotational angle position can be selectively adjusted between the drive part and driven part. Conceivable are also embodiments in which an electromechanical adjustment mechanism is provided, as described, for example, in DE 10 2004 038 681 A1. 
         [0011]    In the fastening arrangement according to the invention, the driven part is provided with a central axial opening that is penetrated by an end section of the camshaft. The end section can have an integral construction with the camshaft or could be a separate component that is locked in rotation with the camshaft. Here, the end section of the camshaft has a thread-bearing threaded section that is screwed with a counter thread of a clamping nut loading the driven part so that the driven part and the camshaft are clamped in the axial direction to provide a rotationally fixed connection. Here, the clamping nut is loaded elastically in the axial direction or releases tension in the axial direction in the clamped state, so that loosening or detachment of the clamping nut is effectively counteracted. 
         [0012]    According to the invention, loosening or detachment of the clamping nut caused by setting the central screw connection can be advantageously counteracted. In this way it is guaranteed that the camshaft adjuster clamped in the axial direction to the camshaft by the clamping nut remains locked in rotation in a desired installation position with the camshaft, wherein reduction of the axial forces acting between the clamping nut and driven part on one side and between the driven part and camshaft on the other side are counteracted. This is especially important when the phase position of the drive part and driven part can be adjusted by a hydraulic adjustment mechanism. For this adjustment, a control valve for controlling pressurized medium is usually arranged in a cavity of the camshaft. The connections of this control valve should be aligned as exactly as possible with the connections of the driven part, in order to guarantee efficient pressurized medium transport. 
         [0013]    The camshaft adjuster according to the invention can involve, in particular, a hydraulic rotary piston adjuster that comprises an outer rotor that can be brought into drive connection with the crankshaft and an inner rotor locked in rotation with the camshaft. Here, the inner rotor is supported in a concentric arrangement with respect to a common rotational axis so that it can be rotated relative to the outer rotor, wherein its rotational angle position relative to the outer rotor can be adjusted by at least one hydraulic adjustment mechanism comprising a pair of pressure chambers acting against each other. 
         [0014]    In one advantageous construction of the fastening arrangement according to the invention, the driven part is clamped by the clamping nut in the axial direction with or against a support surface formed by the camshaft, wherein, between the clamping nut loading the driven part and the driven part, an elastically deformable body is arranged by which the clamping nut is elastically loaded. The elastically deformable body can be connected rigidly, in particular, to the clamping nut. Advantageously, the elastically deformable body is made from spring steel, wherein it can be ensured that the force necessary for the axial clamping of the driven part and camshaft can be transmitted for a suitably elastic compression. 
         [0015]    In another advantageous construction of the fastening arrangement according to the invention, the driven part is clamped by the clamping nut in the axial direction with a support surface formed by the camshaft, wherein the clamping nut itself is constructed as an elastically deformable body. This measure allows a realization of the fastening arrangement according to the invention that is especially simple and economical in industrial series production, wherein the clamping nut is elastically deformed in the tensioned state in the axial direction. For this purpose, the tensioning nut can be formed, for example, as an elastically deformable sheet-metal shaped part. 
         [0016]    In another advantageous construction of the fastening arrangement according to the invention, the driven part is clamped by the clamping nut in the axial direction with a support surface formed by the camshaft, wherein the end section of the camshaft is provided with a deformation section that is arranged between the support surface and the threaded section and is constructed so that it is elastically deformed when the clamping nut is tightened. This measure also allows an especially simple and economical realization of the fastening arrangement according to the invention in industrial series production, wherein the tensioning nut in the clamped state is loaded elastically in the axial direction in the clamped state by the deformation section. The deformation section of the camshaft can have, for this purpose, for example, a smaller wall thickness than adjacent camshaft sections. 
         [0017]    In another advantageous construction of the fastening arrangement according to the invention, the driven part is clamped in the axial direction by the clamping nut with a support surface formed by the camshaft, wherein the driven part is provided with a deformation section that is adjacent to the clamping nut and is constructed so that it is deformed elastically when the clamping nut is tightened. This measure also allows an especially simple and economical realization of the fastening arrangement according to the invention in industrial series production, wherein the clamping nut is loaded elastically in the axial direction in the clamped state by the deformation section of the driven part. 
         [0018]    In another advantageous construction of the fastening arrangement according to the invention, the driven part is clamped in the axial direction by the clamping nut with a support surface formed by the camshaft, wherein the end section of the camshaft is provided with a truncated-cone-shaped conical section that is arranged between the support surface and the threaded section and on which the driven part sits, wherein a friction element, for example, a friction disk, amplifying the friction is arranged between the clamping nut and the driven part. Tension relief of the clamped clamping nut through the conical section can be achieved by this measure, which acts against detachment or loosening of the clamping nut due to setting. Another safety against detachment or loosening of the clamping nut is achieved by the friction element. 
         [0019]    In another advantageous construction of the fastening element according to the invention, the driven part is clamped in the axial direction by the clamping nut with a support surface formed by the camshaft, wherein the end section of the camshaft is provided with a truncated-cone-shaped conical section that is arranged between the contact surface and the threaded section and on which the driven part sits, wherein a connecting element connecting the clamping nut and the end section of the camshaft to each other in a rotationally locked manner is arranged. Through this measure, tension relief of the clamped clamping nut can advantageously be achieved by the conical section, which acts against detachment or loosening of the clamping nut caused by setting. Another safety against detachment or loosening of the clamping nut is achieved by the connecting element. 
         [0020]    In another advantageous construction of the fastening arrangement according to the invention, the driven part is clamped in the axial direction by the clamping nut with a support surface formed by the camshaft, wherein the end section of the camshaft is provided with a conical section formed in the shape of a truncated cone and arranged between the support surface and the threaded section and sitting on the driven part, wherein a wedge ring held in a receptacle of the driven part in some sections is arranged between the clamping nut and the driven part. Through this measure, tension relief of the clamped clamping nut can be advantageously achieved by the conical section, which counteracts a detachment or loosening of the clamping nut caused by setting. 
         [0021]    It is understood that the above constructions of the fastening arrangement according to the invention could be provided alone or in various combinations. 
         [0022]    In the above constructions of the invention, it can be advantageous if the adjustment mechanism comprises a hydraulic control valve that is held in a cavity of the end section of the camshaft and has a valve housing and a control piston held so that it can be displaced in in the axial direction in this valve housing, wherein the valve housing is secured in the axial direction by a securing ring held in a ring groove of the end section. 
         [0023]    In the above constructions of the invention, it can be further advantageous if the adjustment mechanism comprises a hydraulic control valve that is held in a cavity of the end section of the camshaft and has a valve housing and a control piston held so that it can be displaced in the axial direction in this valve housing, wherein the valve housing is secured in the axial direction by a radial collar formed on the clamping nut. 
         [0024]    Another aspect of the invention relates to a fastening arrangement of a camshaft adjuster with a drive part that can be brought into drive connection with a crankshaft, a driven part supported so that it can rotate relative to the drive part, and also a hydraulic adjustment mechanism that can adjust a rotational angle position between the drive part and driven part. Here, the driven part is provided with a central axial opening penetrated by an end section of the camshaft, wherein the driven part is welded with the camshaft. In addition, the hydraulic adjustment mechanism comprises a control valve that is held in a cavity of the end section of the camshaft and has a valve housing and a control piston held so that it can be displaced in the axial direction in this valve housing, wherein the valve housing is secured in the axial direction by a securing ring held in a ring groove of the end section. This aspect of the invention allows, at the same time, a reliable and secure, rotationally locked connection of the driven part to the camshaft adjuster. 
         [0025]    The invention also extends to an internal combustion engine provided with at least one fastening arrangement as described above for a camshaft adjuster. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    The invention will now be explained in more detail with reference to several embodiments, wherein reference is made to the accompanying drawings. Elements that are identical or that have identical actions are designated in the drawings with the same reference numbers. Shown are: 
           [0027]      FIG. 1  is a radial section view of an embodiment of the fastening arrangement according to the invention in which an elastically deformable body is formed on the clamping nut, 
           [0028]      FIG. 2  shows two embodiments of the clamping nut of the fastening arrangement of  FIG. 1 , 
           [0029]      FIG. 3  is a radial section view of another embodiment of the fastening arrangement according to the invention in which an elastically deformable body is formed on the clamping nut, 
           [0030]      FIG. 4  is a radial section view of another embodiment of the fastening arrangement according to the invention in which the clamping nut is constructed as an elastically deformable body, 
           [0031]      FIG. 5  is a radial section view of another embodiment of the fastening arrangement according to the invention in which the camshaft is provided with an elastically deformable section, 
           [0032]      FIG. 6  is a radial section view of another embodiment of the fastening arrangement according to the invention in which the inner rotor is provided with an elastically deformable section, 
           [0033]      FIG. 7  is a radial section view of another embodiment of the fastening arrangement according to the invention in which the camshaft is provided with a truncated cone-shaped section, 
           [0034]      FIGS. 8A-8B  are a radial section view ( FIG. 8A ) and also an axial front view ( FIG. 8B ) of another embodiment of the fastening arrangement according to the invention in which the camshaft is provided with a truncated cone-shaped section, 
           [0035]      FIG. 9  is a radial section view of another embodiment of the fastening arrangement according to the invention in which a wedge ring interacting with a clamping nut is provided, 
           [0036]      FIG. 10  is a radial section of a fastening arrangement according to the invention in which the driven part is welded to the camshaft. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0037]    In the figures, different embodiments of the fastening arrangement according to the invention with a rotary piston adjuster for adjusting a relative rotational angle position between the crankshaft and camshaft are shown schematically. 
         [0038]    First,  FIGS. 1 and 2  will be considered, in which an embodiment of the fastening arrangement according to the invention is shown. Accordingly, the fastening arrangement designated overall with the reference number  1  comprises a hydraulic rotary piston adjuster  2  that has, as a drive part, an outer rotor  3  that can be brought into drive connection with a (not shown) crankshaft by means of a gearwheel  5  and a (not shown) gear train and, as a driven part, an inner rotor  4  arranged so that it can rotate relative to the outer rotor  3 , wherein the outer rotor and inner rotor are arranged concentrically around a common rotational axis  6 . In the radial intermediate space between the outer rotor and inner rotor, a plurality of pressure spaces are formed into each of which extends a vane connected to the inner rotor  4 , by which each pressure space is divided into a pair of pressure chambers acting against each other. Through selective pressurization of, for example, the pressure chambers leading in the drive direction of the inner rotor  4  (pressure chambers “B”) or the pressure chambers trailing accordingly (pressure chambers “A”), a rotational angle position between the inner rotor  4  and outer rotor  3  can be adjusted. At the same time, a desired rotational angle position can be maintained, for example, by hydraulic clamping of the vanes in the pressure chambers. The exact functioning of such a hydraulic rotary piston adjuster  2  has been known for a long time to someone skilled in the art, for example, from the publications mentioned above, so that a more detailed explanation does not have to be discussed here. 
         [0039]    The outer rotor  3  forms a pressure-tight housing for the inner rotor  4 , wherein the pressure spaces or pressure chambers are closed pressure-tight in the axial direction by side components  7  arranged on the end side. The outer rotor  4  is connected with the two side components  7  by axial fastening screws, which are not shown in more detail in  FIG. 1 . 
         [0040]    The inner rotor  4  and the two side components  7  are provided with a central axial opening  8  that is penetrated by an end section  10  of a camshaft  9 . Here, the inner rotor  10  sits on the camshaft  9  with a clearance fit. The end section  10  is provided with a cavity  11  in which a hydraulic control valve designated overall with reference number  12  is held for regulating flows of pressurized medium. The control valve  12  comprises a hollow cylindrical valve housing  13  in which a control piston  14  constructed as a hollow piston is held so that it can be displaced in the axial direction. A valve tappet  16  that is fastened rigidly to a (not shown) magnetic armature of an electromagnet  17  engages on the end surface  15  of the control piston  14  on the left in  FIG. 1 . When the magnetic armature is energized, the valve tappet  16  is offset in the axial direction and here adjusts the control piston  14  in the axial direction against the spring force of a helical compression spring  18 . If the magnetic armature is not energized, the helical compression spring  18  sets the control piston  14  back into its starting position (in  FIG. 1  at the left). The valve housing  13 , the valve tappet  16 , and a sleeve  19  surrounding the valve housing  13  are provided with a series of grooves and openings, in order to supply pressurized medium to or take them away from pressurized medium connections  20  of the inner rotor  4  communicating with the pressure chambers in a desired way according to the position of the control piston  14 . As a rule, oil from the lubricant circuit is used as the pressurized medium that can be fed by means of pressurized medium channels  35 . The exact functioning of the control valve  12  does not need to be discussed in more detail here. 
         [0041]    The position of the control valve  12  is fixed by a securing ring  33  held in the cavity  11  in a ring groove  34 . The securing ring  33  simultaneously forms an axial stop for the control piston  14 . 
         [0042]    Only as an additional point it shall be mentioned that the control valve  12  is provided with a non-return valve  21  that can prevent the pressurized medium paths from becoming empty when the internal combustion engine is stopped and can prevent pressure spikes and pulsations due to fluctuating torques of the camshaft from entering into the oil circuit. 
         [0043]    In  FIG. 1 , a spiral spring  22  can also be seen by which the outer rotor and inner rotor  3 ,  4  can be moved, when the internal combustion engine is stopped, against the friction moment of the camshaft into a thermodynamic phase position (base position) that is favorable for starting the internal combustion engine. 
         [0044]    A rotationally locked connection of the inner rotor  4  to the camshaft  9  is realized by axial clamping by a clamping nut  23 . For this purpose, a threaded section  24  of the end section  10  of the camshaft  9  is provided with an outer thread  25  that is screwed together with the inner thread  26  of the clamping nut  23 . For the axial clamping, the inner rotor  4  is pressed by the clamping nut  23  against a support surface  28  formed by a ring-shaped shoulder  27  of the camshaft  9 . 
         [0045]    As can be inferred, in particular, from  FIG. 2 , an annular ring part  30  is formed on the clamping nut  23  or on a head part  29  carrying the inner thread  26  and constructed in the form of a polygon and connected rigidly to the head part  29 . The ring part  30  is here made, for example, from spring steel. It is provided with a plurality of round or, for example, oval openings  31  through which the ring part  30  obtains a certain amount of elastic deformability in the axial direction. 
         [0046]    If the clamping nut  23  is screwed onto the thread section  24 , the ring part  30  is led into contact against an end-side contact surface  32  of the inner rotor  4 , wherein this is pressed against the support surface  28 . Here, the ring part  30  is compressed elastically. If the screw connection settles in the course of time, then the elastically compressed ring part  30  can compensate for this setting loss, so that loosening or detachment of the clamping nut  23  is prevented. 
         [0047]    Reference is now made to  FIG. 3 , wherein another embodiment of the fastening arrangement according to the invention is shown with reference to a radial section view. To avoid unnecessary repetition, only the differences to the embodiment shown in  FIGS. 1 and 2  will be explained and otherwise reference is made to the statements there. 
         [0048]    Accordingly, the clamping nut  23  is provided with a radially inward directed collar  36  that is used for fixing the position of the control valve  12  instead of a securing ring. The collar  36  is simultaneously used as an axial stop for the control piston  14 . 
         [0049]    Reference is now made to  FIG. 4 , wherein another embodiment of the fastening arrangement according to the invention is shown with reference to a radial section view. To avoid unnecessary repetition, only the differences to the embodiment shown in  FIGS. 1 and 2  will be explained and otherwise reference is made to the statements there. 
         [0050]    Accordingly, the clamping nut  23  is constructed as a sheet-metal shaped part and can be elastically deformed under axial clamping. For this purpose, it comprises an axial ring section  37  that carries the inner thread  26  and is connected to a support section  38  by a radial transition section  39 . If the clamping nut  23  is screwed onto the outer thread  25  of the thread section  24 , the support section  38  is led into contact against the contact surface  32 , so that it is moved relative to the ring section  37  for further tightening of the clamping nut  23  under elastic deformation of the clamping nut  23 . If the screw connection settles in the course of time, then the elastically deformable clamping nut  23  can compensate for this setting loss, so that detachment or loosening of the clamping nut  23  is prevented. 
         [0051]    Reference is now made to  FIG. 5 , wherein another embodiment of the fastening arrangement according to the invention is shown with reference to a radial section view. To avoid unnecessary repetition, only the differences to the embodiment shown in  FIGS. 1 and 2  will be explained and otherwise reference is made to the statements there. 
         [0052]    Accordingly, the clamping nut  23  is not connected to an elastically deformable ring part  30 . Instead, a rigid clamping nut collar  41  connected rigidly to the head part is formed on the head part  29 . With its end surface, the clamping nut collar  41  contacts the contact surface  32  via a friction disk  42 . The friction disk  42  is used to block a detachment or loosening of the clamping nut  23 . In this embodiment, the end section  10  of the camshaft  9  is provided with a (camshaft) deformation section  40  in the region between the threaded section  24  and the support surface  28 . The deformation section  40  is formed by an outer, peripheral (camshaft) ring groove  43  that leads to a weakening of the end section  10  due to the reduced wall thickness. If the clamping nut  23  is screwed onto the outer thread  25  of the threaded section  24 , the clamping nut collar  41  is led with its end surface into contact against the contact surface  32  of the inner rotor  4 . When the clamping nut  23  is tightened, the deformation section  40  of the camshaft  9  is expanded elastically due to the axial clamping of the arrangement. If the screw connection settles in the course of time, the elastically deformable deformation section  40  can compensate this settling loss (through contraction), so that a detachment or loosening of the clamping nut  23  is prevented. 
         [0053]    Reference is now made to  FIG. 6 , wherein another embodiment of the fastening arrangement according to the invention is shown with reference to a radial section view. To avoid unnecessary repetition, only the differences to the embodiment shown in  FIGS. 1 and 2  will be explained and otherwise reference is made to the statements there. 
         [0054]    Accordingly, a region of the inner rotor  4  that borders the ring part  30  and forms the contact surface  32  has an elastically deformable construction and is designated below as (inner rotor) deformation section  44 . In the shown embodiment, the deformation section  44  is formed by an enlarged depth of the pressurized medium connection  20  constructed as a ring groove and adjacent to the contact surface  32 . If the clamping nut  23  is screwed onto the outer thread  25  of the thread section  24 , the ring part  30  is led with its end surface into contact against the contact surface  32  of the inner rotor  4 . If the clamping nut  23  is tightened further, the deformation section  44  of the inner rotor  4  is compressed elastically due to the axial clamping of the arrangement. If the screw connection settles in the course of time, the elastically deformable deformation section  44  can compensate for this settling loss (through contraction), so that detachment or loosening of the clamping nut  23  is prevented. 
         [0055]    Reference is now made to  FIG. 7 , wherein another embodiment of the fastening arrangement according to the invention is shown with reference to a radial section view. To avoid unnecessary repetition, only the differences to the embodiment shown in  FIG. 5  will be explained and otherwise reference is made to the statements there. 
         [0056]    Accordingly, the end section  10  is provided instead of a deformation section  40  between the thread section  24  and the support surface  28  with a truncated cone-like conical section  45 . The axial opening  8  of the inner rotor  4  is constructed here with a force fit. If the clamping nut  23  is screwed onto the outer thread  25  of the threaded section  24 , the clamping nut collar  41  is led with its end surface into contact against the contact surface  32  of the inner rotor  4 . If the clamping nut  23  is tightened further, the inner rotor  4  is pressed against the support surface  28 . In addition, the inner rotor  8  is clamped in the axial and radial directions on the axial opening  8  with the conical section  45 . In this way, the clamping nut  23  is relieved of stress, which counteracts the settling of the screw connection. 
         [0057]    Reference is now made to  FIG. 8 , wherein another embodiment of the fastening arrangement according to the invention is shown with reference to a radial section view. To avoid unnecessary repetition, only the differences to the embodiment shown in  FIG. 7  will be explained and otherwise reference is made to the statements there. 
         [0058]    Accordingly, fastening tabs  46  distributed around the periphery are provided that are locked in rotation both with the end section  10  of the camshaft  9  and also with the clamping nut  23 . For this purpose, the fastening tabs  46  are each held with one end in grooves of the end section  10  that are not shown in more detail in  FIG. 8 . With their other end, the fastening tabs  46  are held in tab receptacles  47  of the clamping nut  23 . The fastening tabs  46  can be easily brought into the tab receptacles  47  by bending after the clamping nut  23  is tightened. Through the fastening tabs  46  connecting the clamping nut  23  and the camshaft  9  to each other in a rotationally fixed manner, detachment or loosening of the clamping nut  23  is counteracted. 
         [0059]    Reference is now made to  FIG. 9 , wherein another embodiment of the fastening arrangement according to the invention is shown with reference to a radial section view. To avoid unnecessary repetition, only the differences to the embodiment shown in  FIGS. 1 and 2  will be explained and otherwise reference is made to the statements there. 
         [0060]    Accordingly, the clamping nut  23  is formed merely as a head part  29 . In a wedge groove  48  formed in the region of the contact surface  32  of the inner rotor  4 , an elastically deformable wedge ring  49  is partially held (in some sections). If the clamping nut  23  is screwed onto the outer thread  25  of the thread section  24 , an end surface of the head part  29  is led into contact against the wedge ring  49 , so that this is pressurized. If the screw connection settles in the course of time, the wedge ring  49  can compensate for this settling loss (through contraction), so that detachment or loosening of the clamping nut  23  is prevented. In addition, loosening of the screw connection is counteracted by the friction properties of the wedge ring  49 . 
         [0061]    Reference is now made to  FIG. 10 , wherein another embodiment of the fastening arrangement according to the invention is shown with reference to a radial section view. To avoid unnecessary repetition, only the differences to the embodiment shown in  FIGS. 1 and 2  will be explained and otherwise reference is made to the statements there. 
         [0062]    Accordingly, the inner rotor  4  is not clamped in the axial direction by a clamping nut with the camshaft  9 , but instead by a peripheral weld seam  50  with the end section  10  of the camshaft  9 . The control valve  12  is secured in the axial direction by the securing ring  33  held in the cavity  11  in a ring groove  34 . 
         [0063]    The fastening arrangement according to the invention thus advantageously allows that detachment or loosening of the clamping nut of a central screw connection is effectively counteracted for the axial clamping of the camshaft adjuster with the camshaft, in order to guarantee, in particular, an exact positioning of the driven part relative to the camshaft. The measures explained above in connection with the different embodiments for achieving this goal can be realized alone or in any combination. 
       List of Reference Symbols 
       [0064]      1  Fastening Arrangement 
         [0065]      2  Rotary Piston Adjuster 
         [0066]      3  Outer Rotor 
         [0067]      4  Inner Rotor 
         [0068]      5  Gearwheel 
         [0069]      6  Rotational Axis 
         [0070]      7  Side Component 
         [0071]      8  Axial Opening 
         [0072]      9  Camshaft 
         [0073]      10  End Section 
         [0074]      11  Cavity 
         [0075]      12  Control Valve 
         [0076]      13  Valve Housing 
         [0077]      14  Control Piston 
         [0078]      15  End Surface 
         [0079]      16  Valve Tappet 
         [0080]      17  Electromagnet 
         [0081]      18  Helical Compression Spring 
         [0082]      19  Sleeve 
         [0083]      20  Pressurized Medium Connection 
         [0084]      21  Non-return Valve 
         [0085]      22  Spiral Spring 
         [0086]      23  Clamping Nut 
         [0087]      24  Threaded Section 
         [0088]      25  Outer Threading 
         [0089]      26  Inner Threading 
         [0090]      27  Shoulder 
         [0091]      28  Support Surface 
         [0092]      29  Head Part 
         [0093]      30  Ring Part 
         [0094]      31  Breakthrough 
         [0095]      32  Contact Surface 
         [0096]      33  Securing Ring 
         [0097]      34  Ring Groove 
         [0098]      35  Pressurized Medium Channel 
         [0099]      36  Collar 
         [0100]      37  Ring Section 
         [0101]      38  Support Section 
         [0102]      39  Transition Section 
         [0103]      40  (Camshaft) Deformable Section 
         [0104]      41  Clamping Nut Collar 
         [0105]      42  Friction Disk 
         [0106]      43  (Camshaft) Ring Groove 
         [0107]      44  (Inner rotor) Deformable Section 
         [0108]      45  Conical Section 
         [0109]      46  Fastening Tab 
         [0110]      47  Tab Receptacle 
         [0111]      48  Wedge Groove 
         [0112]      49  Wedge Ring 
         [0113]      50  Weld Seam