Abstract:
A transmitter for a synchronising assembly of a manual transmission has a transmitter disk and at least one clutch disk which is arranged on a side surface of the transmitter disk. The clutch disk and the transmitter disk are fixedly connected together by local welding points. A method for producing a transmitter for a synchronising assembly of a manual transmission consists of providing a clutch disk and a transmitter disk. Then, the clutch disk and the transmitter disk are fastened together by means of projection welding. Finally, the thus formed assembly is hardened.

Description:
[0001]    The invention relates to a transmitter for a synchronising assembly of a manual transmission, having a transmitter disk and at least one clutch disk which is arranged on a side surface of the transmitter disk. The invention also relates to a method for producing a transmitter for a synchronising assembly of a manual transmission. 
       BACKGROUND OF THE INVENTION 
       [0002]    A synchronising assembly of a manual transmission, as used in particular in motor vehicles, is used, in general terms, to establish a rotationally-fixed connection between a transmission shaft and a gear wheel or toothed wheel arranged on the transmission shaft as an idler wheel. In a first step of the gear-shifting process, the synchronising assembly ensures that the rotational speed of the gear wheel to be shifted matches the rotational speed of the transmission shaft. In a second step, a rotationally-fixed connection is established between the transmission shaft and the gear wheel. The corresponding gear is then shifted. 
         [0003]    A widely used type of synchronising assembly is known under the name “BorgWarner synchronisation”. This synchronising assembly uses a shift collar which is arranged on a synchronising body in a rotationally-fixed but axially displaceable manner, said body being connected to the transmission shaft for conjoint rotation therewith. The shift collar can be displaced from an initial position in the axial direction to a gear wheel. A synchronising ring is initially activated hereby which synchronises the rotational speed of the gear wheel with the rotational speed of the transmission shaft. As soon as this process is complete, the shift collar can be further displaced in the axial direction until it establishes a rotationally-fixed connection with the corresponding gear wheel. 
         [0004]    As an alternative to this type of synchronising assembly, a type which uses the transmitter mentioned in the introduction is known. An example of this can be seen in DE 10 2010 036 278 A1. In general terms, the transmitter combines the synchronising body and the shift collar in one component which is mounted so as not to rotate relative to the transmission shaft and can be displaced in the axial direction. If the transmitter is displaced in the axial direction from a neutral position, a synchronising ring (or even an assembly consisting of a plurality of synchronising rings) is initially activated, whereby the rotational speed of the corresponding gear wheel is synchronised with the rotational speed of the transmission shaft. In a second step, the transmitter can then be interconnected, whereby a rotationally-fixed connection is established between the transmission shaft and the corresponding gear wheel. 
         [0005]    The object of the invention is to provide a transmitter which can be produced at low cost. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0006]    In order to achieve this object, a transmitter is provided which has a transmitter disk and at least one clutch disk which is arranged on a side surface of the transmitter disk. The clutch disk and the transmitter disk are fixedly connected together by local welding points. These can be produced quickly, reliably and at low cost, for example by resistance welding. Since the torque is transmitted from the transmission toothed wheels to the transmission shaft substantially directly via the clutch disks and not via the transmitter disk, the welding points are also not subjected to any particularly high loads. 
         [0007]    Projections are preferably provided which form the welding points. This ensures that the welding points are produced precisely at the desired positions. 
         [0008]    In accordance with a preferred embodiment, spacers are provided, on which the projections are formed, in particular on the transmitter disk. The spacers allow a pressure piece to be arranged in the transmitter disk, the dimensions of which pressure piece are larger in the axial direction than the thickness of the transmitter disk. This allows in particular a comparatively robust compression spring to be arranged in the transmitter disk. 
         [0009]    In order to achieve the above-mentioned object, a method for producing a transmitter for a synchronising assembly of a manual transmission is also provided in accordance with the invention, said method comprising the following steps: initially, a clutch disk and a transmitter disk are provided. Then, the clutch disk and the transmitter disk are fastened together by means of projection welding. Then, the thus formed assembly is hardened. This sequence of welding and hardening ensures that the material has, during welding, the optimum properties therefor. 
         [0010]    The assembly can either be freely hardened, i.e. hardened and quenched or it is also possible for the assembly to be hardened on a mandrel which, for example, engages into an internal toothed arrangement of the clutch disk and thus limits the distortion due to hardening at that location. 
         [0011]    In accordance with a preferred embodiment, provision is made that the transmitter disk is provided with at least one recess, and that after the assembly is hardened a pressure piece is mounted in the recess. The pressure piece can be inserted into the recess allocated thereto in an extremely simple manner in mechanical terms, wherein it is optionally guided between the clutch disks. 
         [0012]    In accordance with a preferred embodiment of the invention, provision is made that the pressure piece is clipped into the recess. This ensures that the pressure piece remains in the recess allocated thereto after being assembled without any further aids. 
         [0013]    In accordance with a preferred embodiment of the invention, provision is made that the pressure piece is provided with a base part and a guide part, wherein the base part is located between two clutch disks which are arranged on sides of the transmitter disk facing away from each other, and that the guide part is guided in the axial direction between edges of the recess which are opposite one another in the circumferential direction. This design produces a particularly precise guidance of the pressure piece in the recess, whereby the shifting behaviour is optimised. 
         [0014]    Advantageous embodiments of the invention are apparent from the dependent claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The invention will be described hereinafter with the aid of an embodiment which is illustrated in the attached drawings. In the drawings: 
           [0016]      FIG. 1  shows a schematic longitudinal sectional view of a synchronising assembly having a transmitter in accordance with the invention; 
           [0017]      FIG. 2  shows an exploded view of the synchronising assembly of  FIG. 1 ; 
           [0018]      FIG. 3  shows a sectional view along plane of  FIG. 1 ; 
           [0019]      FIG. 4  shows a sectional view along plane IV-IV of  FIG. 3 ; 
           [0020]      FIG. 5  shows a sectional view along plane V-V of  FIG. 3 ; 
           [0021]      FIG. 6  shows an enlarged view of the section VI of  FIG. 3 ; 
           [0022]      FIG. 7 a    shows a sectional view along plane VII-VII of  FIG. 3 ; 
           [0023]      FIGS. 7 b  to 7 e    show different embodiment variants of the region marked with VII in  FIG. 7   a;    
           [0024]      FIG. 8  shows a perspective view of the transmitter disk of the transmitter in accordance with the invention having pressure pieces mounted therein; 
           [0025]      FIG. 9  shows a perspective view of a pressure piece which is used in the transmitter in accordance with the invention; 
           [0026]      FIG. 10  shows a perspective view of the guide part of the pressure piece of  FIG. 9 ; 
           [0027]      FIG. 11  shows a bottom view of the guide part of  FIG. 10 ; 
           [0028]      FIG. 12  shows a side view of the guide part of  FIG. 10 ; 
           [0029]      FIG. 13  shows a plan view of the guide part of  FIG. 10 ; 
           [0030]      FIG. 14  shows a perspective view of the base part of the pressure piece of  FIG. 9 ; 
           [0031]      FIG. 15  shows a bottom view of the base part of  FIG. 9 ; 
           [0032]      FIG. 16  shows a side view of the base part of  FIG. 9 ; 
           [0033]      FIG. 17  shows a plan view of the base part of  FIG. 9 ; 
           [0034]      FIG. 18  shows a side view of the transmitter disk; 
           [0035]      FIG. 19  shows a sectional view along line XIX-XIX of  FIG. 18 ; 
           [0036]      FIG. 20  shows a sectional view along plane XX-XX of  FIG. 18 ; 
           [0037]      FIG. 21  shows a sectional view along plane XXI-XXI of  FIG. 18 ; and 
           [0038]      FIG. 22  shows a sectional view along plane XXII-XXII of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0039]      FIG. 1  schematically shows a synchronising assembly which comprises two transmission toothed wheels  1 ,  2  which can each be connected to a transmission shaft  3  for conjoint rotation therewith depending upon the shifted gear. For this purpose, a transmitter  10  is provided which can be adjusted in the axial direction relative to the transmission shaft  3 . 
         [0040]    Where the terms “axial” or “radial” are used hereinafter, they refer to the rotational axis of the transmission shaft  3  and of the transmitter  10 . 
         [0041]    The basic design of the synchronising assembly is explained hereinafter with reference to  FIGS. 1 to 5 , whilst details will be explained further hereinafter with reference to  FIGS. 6 to 22 . 
         [0042]    The transmitter  10  comprises a transmitter disk  12  which is provided with a clutch disk  14  on each of its two side surfaces. Each clutch disk  14  comprises, on its radially inner circumference, a transmission shaft toothed arrangement  16  and, on its radially outer circumference, a clutch toothed arrangement  18  (see in particular  FIG. 2 ). 
         [0043]    The transmission shaft toothed arrangements  16  of the clutch disks  14  are accommodated on an external toothed arrangement  20  of a transmitter sleeve  22  in a rotationally-fixed but axially displaceable manner. In turn, the transmitter sleeve  22  is arranged on the transmission shaft  3  in a rotationally-fixed manner. For this purpose, the transmitter sleeve  22  can be provided with an internal toothed arrangement  24  (see in particular  FIGS. 3 to 5 ). 
         [0044]    The clutch toothed arrangement  18  of each clutch disk  14  is provided so as to co-operate with a gear wheel clutch toothed arrangement  26  allocated thereto and provided on the transmission toothed wheels  1 ,  2 . In the illustrated exemplified embodiment, each gear wheel clutch toothed arrangement  26  is provided on the inner surface of a friction ring  28  which is provided on its outer side with a slightly conical friction surface  30 . Each friction ring  28  is connected, e.g. welded or soldered, to the transmission toothed wheel  1 ,  2  allocated thereto for conjoint rotation therewith. 
         [0045]    Arranged on the transmitter disk  12  are two synchronising rings  32  which lie one on either side of the transmitter disk  12  and are provided so as to co-operate with the friction surfaces  30  of the friction rings  28 . For this purpose, the synchronising rings  32  are provided with a friction lining  34  on their inner surface. 
         [0046]    The synchronising rings  32  are basically connected to the transmitter disk  12  for conjoint rotation therewith but they can also rotate relative thereto about a small angular range. Furthermore, the synchronising rings  32  are attached in the axial direction to the transmitter disk  12  but they can also be adjusted to a certain extent in the axial direction starting from a centre or initial position. 
         [0047]    Each synchronising ring  32  is provided with three different types of lugs which extend through allocated openings, recesses or apertures in the transmitter disk, or at least extend into same: connecting lugs  36 ,  37 , stop lugs  38  and locking lugs  40 . 
         [0048]    The connecting lugs  36 ,  37  are used to mechanically connect the two synchronising rings  32  to each other in the axial direction. For this purpose, each synchronising ring  32  has a connecting lug  36  which has a wide head at its free end and transitions into the synchronising ring-side section of the connecting lug  36  via a narrower neck. 
         [0049]    Each connecting lug  37  has an aperture which has a larger section adapted to the dimensions of the head of the connecting lug  36  and a narrower section adapted to the dimensions of the neck of the connecting tug  36 . 
         [0050]    The connecting lugs  36 ,  37  extend, when engaged with each other, through two openings  42 , allocated thereto, in the transmitter disk. The width of the openings  42  in the circumferential direction is greater than the width of the connecting lugs  36 ,  37  in the circumferential direction. 
         [0051]    The stop lugs  38  have a constant width and extend into apertures  44  which are likewise provided in the transmitter disk  12 . The width of the apertures  44  in the circumferential direction is slightly greater than the width of the stop lugs  38  in the circumferential direction. 
         [0052]    The locking lugs  40  each extend into a recess  46  in the transmitter disk  12 . The mutually facing ends of the locking lugs  40  in the initial position are located opposite each other and centrally within the recess  46  (see in particular  FIG. 4 ). 
         [0053]    Each locking lug  40  comprises, in proximity to its free end, two locking surfaces  48  which face away from each other and extend in an inclined manner relative to the extension direction of the locking lugs  40 . In this case, the locking surfaces  48  form, with an extension of the outer edges of the locking lugs  40 , an angle in the order of magnitude of 60°. 
         [0054]    The locking surfaces  48  co-operate with the edges  50  of the corresponding recess  46 , which edges are opposite each other and extend in parallel with each other, and, more specifically, the locking surfaces each co-operate with a bevel  52  which is provided on the corresponding edge. The orientation of the bevels  52  corresponds to the orientation of the locking surfaces  48  so that these can lie flat against each other. 
         [0055]    The locking lugs  40  comprise, on the radially inner side of each of their free ends, a centring bevel  54  (see in particular  FIG. 4 ), on which an outwardly directed pressure surface  56  of a pressure piece  58  engages. 
         [0056]    Each pressure piece  58  comprises a guide part  60  which is held between the edges  50  of the corresponding recess  46  in the axial direction, a base part  62  which is arranged on the radially inner end of the recess  46 , and a compression spring  64  which exerts a force upon the guide part  60  and the base part  62 , said force intending to move the guide part  60  away from the base part  62 . 
         [0057]    As can be seen in particular in  FIG. 2 , the transmitter comprises four locking lugs  40  per synchronising ring  32 , which lugs are evenly spaced apart from each other in the circumferential direction, and two connecting lugs  36 ,  37  which lie diametrically opposite one another, and two stop lugs  38  which lie diametrically opposite one another. The diameter defined by the two connecting lugs  36 ,  37  is perpendicular to the diameter defined by the two stop lugs  38 . In other words: the connecting lugs and the stop lugs are arranged so as to be staggered with respect to one another by an angle of 90°. 
         [0058]    The process of shifting a gear and synchronising the rotational speeds of the transmission shaft and of the transmission toothed wheel to be shifted is basically performed in the same manner as described in DE 10 2010 036 278 A1: if a gear is to be shifted, the transmitter disk  12  is displaced in the axial direction by means of an actuating device (not shown herein). The two synchronising rings  32  connected together are entrained in the axial direction because the pressure surfaces  56  of the pressure pieces  58  mounted on the transmitter disk  12  lie between the two V-shaped centring bevels  54  and the spring force provided by the compression springs  64  produces sufficient friction. 
         [0059]    As soon as the synchronising ring  32  comes into engagement with the friction surface  30 , allocated to the transmission toothed wheel to be shifted, the synchronising ring (assuming a difference in rotational speed between the transmission toothed wheel and the transmission shaft) is entrained in the circumferential direction until one of the outer edges of each of the two stop lugs  38  comes to lie against the edge of the corresponding aperture  44  in each case. The position of the synchronising rings is hereby defined in the circumferential direction. 
         [0060]    If, in this state, the transmitter disk  12  is further displaced in the axial direction, it is displaced axially relative to the synchronising rings  32  because the active synchronising ring  32  is supported in the axial direction on the friction surface  30  of the transmission toothed wheel to be shifted. By way of this axial displacement of the transmitter disk  12  relative to the synchronising ring  32 , one of the bevels  52  at the edge of each recess  46  comes to lie against one of the locking surfaces  48  on each of the locking lugs  40 , and in particular the ones which have been moved towards each other owing to the relative movement between the synchronising rings  32  and the transmitter disk  12 . 
         [0061]    The transmitter disk  12  can only then be further adjusted in the axial direction if the synchronising rings  32  can, via the mutually co-operating locking surfaces  48  of the synchronising rings and bevels  52  of the transmitter disk, be rotated back in the circumferential direction to the extent that the locking surfaces  48  no longer lie against the bevels  52  but rather the outer edges of the locking lugs  40  extending in the axial direction slide along the edges  50  of the recesses  46 . However, it is only possible to re-adjust the synchronising ring  32  in the circumferential direction (expressed simply) when the rotational speeds of the transmission toothed wheel to be shifted and the transmission shaft match one another. Specifically: the synchronising ring  32  can then be unlocked if the unlocking moment (reverse torque), resulting from the shifting force and the locking geometry (bevel angle and coefficient of friction) is greater than the synchronising moment on the friction surface of the synchronising ring. 
         [0062]    If the rotational speeds of the transmission toothed wheel and the transmission shaft match one another, the synchronising rings  32  are rotated slightly in the circumferential direction (owing to the effect of the bevels  52  on the locking surfaces  48 ), and therefore the transmitter disk  12  can be further shifted in the axial direction. The guide parts  60  of the pressure pieces  58  yield radially inwards because they are adjusted inwardly by the centring bevels  54 . 
         [0063]    The transmitter disk  12  is adjusted in the axial direction to the extent that the clutch toothed arrangement  18  of the clutch disk  14  located at the front in the adjusting direction engages into the corresponding gear wheel clutch toothed arrangement  26 . As a result, a rotationally-fixed connection is established from the transmission shaft  3 , via the transmitter sleeve  22 , the transmission shaft toothed arrangement  16 , the clutch disk  14 , the clutch toothed arrangements  18  and the gear wheel clutch toothed arrangement  26 , to the corresponding transmission toothed wheel. 
         [0064]    The design of the pressure pieces  58  and their attachment in the recesses  46  of the transmitter disk  12  will be explained hereinafter with reference to  FIGS. 6 to 17 . 
         [0065]    The guide part  60  of each pressure piece  58  consists of synthetic material and is formed in particular as an injection moulded part. It comprises a cross-bar  70  (see in particular  FIGS. 9, 10 and 12 ), wherein two latching arms  72  extend in parallel with each other in the same direction from the ends of the cross-bar which face away from each other. The cross-bar  70  is provided with the pressure surface  56  on the side opposite the latching arms  72 . This pressure surface is slightly curved, wherein the radius of curvature which determines the curvature in the circumferential direction is on a central plane M on the side towards which the two latching arms  72  also extend (see the indicated radius r in  FIG. 12 ). The radius r approximately corresponds to the radius on which the locking lugs  40  lie. 
         [0066]    The outer edges of the latching arms  72  facing away from each other are each provided with a guide contour  74  which is formed by guide surfaces  76  arranged in a V-shape (see  FIG. 7 a   ). The apexes of the two V-shaped guide contours  74  are rounded and the two apexes face each other. In other words: the guide contours  74  are formed as grooves along the outer edges of the latching arms  72 . 
         [0067]    Designs other than the V-shape can also be used in the region of the contact between the latching arms  72  and the transmitter disk. Examples are shown in  FIGS. 7 b    to  7   e.    
         [0068]    In  FIG. 7 b   , the edge of the transmitter disk  12  is concave on the side thereof facing the corresponding latching arm  72 , and specifically has a rectangular groove (as seen in cross-section). A complementarily convex outer edge of the corresponding latching arm  72  engages into said groove. 
         [0069]    In  FIG. 7 c   , the edge of the transmitter disk  12  is likewise concave on the side thereof facing the corresponding latching arm  72 , and specifically is formed as a depression with a curved bottom (as seen in cross-section). A complementarily convex outer edge of the corresponding latching arm  72  engages into said depression. 
         [0070]    In  FIG. 7 d   , the edge of the transmitter disk  12  is convex on the side thereof facing the corresponding latching arm  72 , and specifically has a rectangular protrusion (as seen in cross-section). Said protrusion is accommodated in a complementary groove having a rectangular cross-section in the outer edge of the corresponding latching arm  72 . 
         [0071]    In  FIG. 7 e   , the edge of the transmitter disk  12  is likewise convex on the side thereof facing the corresponding latching arm  72 , and specifically is formed as a protrusion with a curved end face (as seen in cross-section). Said protrusion is accommodated in a complementary convex depression in the outer edge of the corresponding latching arm  72 . 
         [0072]    Formed on each of the mutually facing inner edges of the latching arms  72  are two V-shaped sliding guide surfaces  78  (see in particular  FIG. 11 ). The apex of the V-shaped contour is also rounded in this case and the apexes fie opposite one another. The two V-shaped contours on the inner side and outer side of the latching arms  72  are thus oriented in the same direction. However, the angles are different. Whilst the guide surfaces  76  together form an angle of less than 90°, the sliding guide surfaces  78  together form an angle of greater than 90° (likewise as measured on the “inner side” of the V-shaped contour). The crown angle for the guide contour  74  is in the order of magnitude of 60° whilst the crown angle for the sliding guide contour formed by the sliding guide surfaces  78  is in the order of magnitude of 120°. 
         [0073]    The two latching arms  72  are each provided with a latching configuration  80  on their inner side on the free end, said configuration being in the form of a bead or protrusion (see in particular  FIG. 12 ). 
         [0074]    The base part  62  (see in particular  FIGS. 9 and 14 to 17 ) comprises a planar bottom part  82 , from which two post-like protrusions  84  extend, which protrusions together form a spring bearing for the compression spring  64 . A circular depression  86  is provided in this case between the two protrusions  84  and is used to receive an and of the compression spring  64 . However, the depression is not absolutely necessary. 
         [0075]    The two protrusions  84  are curved on their mutually facing inner sides, wherein the radius of curvature is adapted to the outer diameter of the compression spring  64 . The outer surfaces, facing away from each other, of the protrusions  84  are provided with sliding guide surfaces  88  which are inclined in the same manner as the sliding guide surfaces  78  on the guide part  60 . The sliding guide surfaces  78  of the guide part  60  form, together with the sliding guide surfaces  88  of the base part  62 , a sliding guide, along which the guide part  60  is guided and received thereon so as to be displaceable relative to the base part  62 . 
         [0076]    Each of the sliding guide surfaces  88  of the protrusions  84  of the base part  62  is provided with a latching configuration  90  which likewise is in the form of a bead or protrusion. The latching configuration  90  is arranged, as seen starting from the bottom part  82 , in the order of magnitude of a third of the height of the protrusions  84 . 
         [0077]    The smaller end faces, facing away from each other, of the bottom part  82  of the base part  62  are each formed as clip-in ends  92 . For this purpose, small, bead-like protrusions are provided on the end faces. 
         [0078]    Each pressure piece  58  forms a pre-assembled unit (see  FIG. 9 ). This unit consists of the base part  62 , the guide part  60  and the compression spring  64 . 
         [0079]    In order to assemble a pressure piece, the compression spring  64  is inserted between the two protrusions  84 . Then, the guide part  60  is placed on the base part  62  such that the latching configurations  80  of the latching arms  72  latch behind the latching configurations  90  of the protrusions  84  (see the state in  FIG. 9 ). In this state, the compression spring  64  is slightly biassed. However, it is not able to separate the guide part  60  from the base part  62  because its spring force is lower than the holding force of the form-fitting coupling of the latching configurations  80  and  90 . 
         [0080]    The pressure pieces  58  are inserted into the recesses  46  of the transmitter disk  12  such that the guide surfaces  76  co-operate with the bevels  52  on the edges  50  of the recesses  46  (see in particular  FIG. 7 ). The guide parts  60  are hereby accommodated in the recesses  46  so as to be displaceable in the radial direction, but are reliably held therein in the axial direction. 
         [0081]    Insertion of the pressure pieces  58  into the recesses  46  is facilitated by insertion contours  53  which are attached to the edges  50  on the radially inner side (see in particular  FIG. 6 ). 
         [0082]    Upon assembly of the pressure pieces  58  in the recesses  46  of the transmitter disk  12 , the clip-in ends  92  of the base parts  62  engage into a suitably formed holding section  47  on the radially inner end of each recess  46  (see in particular  FIG. 6 ). As a result, the pressure pieces  58  are pre-assembled in the transmitter disk  12  (see also  FIG. 8 ). 
         [0083]    If the synchronising rings  32  are mounted on the transmitter disk  12 , the pressure surfaces  56  of the pressure pieces  58  adjoin the two mutually facing centring bevels  54  of the locking lugs  40  (see  FIGS. 4 and 6 ). Since the pressure surfaces  56  are curved in the circumferential direction, a line contact is produced. 
         [0084]    When the transmitter disk  12  is mounted on the transmitter sleeve  22 , the base part  62  lies on the outer toothed arrangement  20  of the transmitter sleeve  22  (see  FIG. 6 ) and therefore the base part  62  is supported in the radial direction. Therefore, if the guide part  60  is adjusted inwardly in the radial direction (in an interconnected position of the transmitter disk  12 ) and thus the compression spring  64  is biassed to a greater extent than in the initial state, the base part  62  also cannot be pushed inwards out of the holding section  47 . 
         [0085]    The manner in which the clutch disks  14  are fastened to the side surfaces of the transmitter disk  12  will be described hereinafter with reference to  FIGS. 18 to 22 . 
         [0086]    The two clutch disks  14  are welded to the transmitter disk  12 , and in particular by projection welding (i.e. resistance welding at predetermined points). 
         [0087]    Each clutch disk  14  is fastened to the transmitter disk  12  at four welding points  100  evenly spaced apart from each other in the circumferential direction. These are defined by material protrusions  102  which are produced alternately in opposite directions by plastic deformation of the material of the transmitter disk  12 , and in particular in a direction perpendicular to the plane which is defined by the transmitter disk (perpendicular to the plane of the drawing of  FIG. 18  and in the direction of the arrow P in  FIG. 19 ). A depression  104  is thereby formed on the side opposite the material protrusion  102 . 
         [0088]    The material protrusions  102  which subsequently form the welding points  100  are formed on spacers  106  which are likewise formed by plastic deformation of the material of the transmitter disk  12 . The spacers  106  are produced in that the transmitter disk  12  is provided with an embossed portion  108  (see in particular  FIG. 19 ) on the opposite side. 
         [0089]    As can be seen in  FIG. 18 , the spacers  106  and the embossed portions  108  are each arranged in pairs in the same sequence between adjacent recesses  46  for the pressure pieces  58 . 
         [0090]    The spacer  106  ensures that a distance a is provided in each case between the transmitter disk  12  and the clutch disks  14  (see for example  FIG. 22 ). The distance a allows a compression spring  64  to be used which has a diameter greater than the thickness of the transmitter disk  12 . A spring having a higher spring constant can hereby be used. 
         [0091]      FIG. 19  illustrates the spacers  106  in a state in which the transmitter disk  12  is produced as a blank. The material protrusions  102  are provided in this state. 
         [0092]    In order to connect the transmitter disk  12  to the two clutch disks  14 , these are arranged and oriented on the two side surfaces of the transmitter disk  12 . Then, they are fastened to one another by projection welding or resistance welding, wherein the material protrusions  102  melt on the spacers  106  so that the clutch disks  14  lie flat on the spacers  106 . This can be seen on the one hand in  FIG. 22  and on the other hand in  FIG. 20  in which the spacers  106  are shown without the material protrusions  102 . Welding points  100  remain in place of the material protrusions  102 , wherein the clutch disks  14  are materially bonded to the transmitter disk  12  at said welding points. 
         [0093]    After the clutch disks  14  have been welded to the transmitter disk  12 , the thus formed assembly is hardened. This can occur in that the assembly is heated and then quickly cooled. 
         [0094]    Depending upon the distortion due to hardening which is to be expected and can be tolerated, the assembly can either be freely hardened or even hardened on a mandrel, the outer contour of which corresponds precisely to the transmission shaft toothed arrangement  16  of the clutch disks  14 ; it is hereby ensured that the transmission shaft toothed arrangements  16  have a desired contour even after hardening. 
         [0095]    After hardening, the pressure pieces  58  can be mounted in the recesses  46  where the base parts  62  latch into the holding sections  47 .