Abstract:
A transmitter for producing a rotationally fixed connection between a transmission shaft and a transmission gear rotatably mounted on the transmission shaft comprises a transmitter disk and a clutch toothing associated with the transmitter disk. The transmitter disk is provided with a transmitter toothing on its outside.

Description:
[0001]    This invention relates to a transmitter for a manual transmission, in particular a transmitter for a manual transmission of a motor vehicle, an assembly with transmitter, transmission shaft and transmission gear as well as a transmission. 
       BACKGROUND OF THE INVENTION 
       [0002]    In manual transmissions, as they are used in particular in motor vehicles, the synchronising assembly serves to produce a rotationally fixed connection between a transmission shaft and a transmission gear or gear wheel arranged on the transmission shaft as idler gear. In a first step of the shifting operation, the synchronizing assembly ensures that the speed of the transmission gear to be shifted is adapted to the speed of the transmission shaft. In a second step, a rotationally fixed connection between the transmission shaft and the transmission gear then is produced. The corresponding gear then is engaged. 
         [0003]    What is generally known are synchronizing assemblies which as essential components include a synchronizer hub, thrust pieces accommodated therein, synchronizer rings as well as a selector sleeve. Upon actuation of the selector sleeve, one of the synchronizer rings is pressed against a friction surface, which is associated with the transmission gear to be shitted, via the thrust pieces and/or via the blocking bevels. When the speed of the transmission gear is synchronized with the speed of the transmission shaft, the selector sleeve can be shifted through completely, so that it engages into a toothing associated with the transmission gear. In this way, a rotationally fixed connection is produced from the synchronizer hub to the transmission gear. 
         [0004]    What is also known are synchronizing assemblies which instead of a synchronizer hub also employ a so-called transmitter, which generally speaking combines the function of the synchroniser hub, the thrust pieces and the selector sleeve. The basic construction of a transmission with such synchronizing assembly will be explained below with reference to  FIGS. 1 to 8 . 
         [0005]    The transmission contains a transmission shaft  10  on which two transmission gears  12 ,  14  are arranged. The two transmission gears  12 ,  14  are designed as idler gears, i.e. can rotate relative to the transmission shall. To each transmission gear  12 , 14  a transmission gear toothing  16  is non-rotably associated. The same is provided as internal toothing on a separate component  17  which is firmly connected with the corresponding transmission gear  12 , 14 . 
         [0006]    Between the two transmission gears  12 ,  14  a transmitter  18  is arranged, which here is formed by a transmitter disk  20  and two clutch disks  22 . The two clutch disks  22  are arranged on the one and on the other side of the transmitter disk  20  and include a clutch disk external toothing  24  as well as a clutch disk internal toothing  26 . The external toothing  24  is designed complementary to the transmission gear toothing  16 , and the internal toothing  26  is in engagement with a transmission shaft toothing  28 . Thus, the clutch disks  22  are non-rotatably coupled with the transmission shaft  10  in circumferential direction, but can be shifted on the transmission shaft in an axial direction. 
         [0007]    On the one and on the other side of the transmitter disk  20  a synchronizer ring  30  is arranged, which can cooperate with a friction surface  32  associated with the corresponding transmission gear  12 ,  14 . The two synchronizer rings include several carriers  34 , which extend in recesses  36  in the transmitter disk  20 , and two diametrically opposed connecting tabs  38  which extend through connecting openings  40  in the transmitter disk  20  (see in particular  FIG. 3 ). The connecting tabs  38  serve to couple the two synchronizer rings with each other in an axial direction. In the coupled condition (see  FIG. 4 ), the free ends of the carriers  34  of the two synchronizer rings  30  closely face each other. 
         [0008]    In each of the recesses  36  a thrust piece  42  (see in particular  FIGS. 5 and 6 ) is arranged, which is each urged to the outside in radial direction by a spring  44 . At the radially outer end of each thrust piece a pre-synchronizing surface  46  is formed, which rests against pre-synchronizing bevels  48  formed at the free ends of the earners  34  on the radially inner side (see  FIG. 7 ). The pre-synchronizing bevels  48  of the opposed carriers  34  are aligned such that a V with large opening angle is formed, whose tip points radially to the outside. 
         [0009]    At the carriers  34  blocking surfaces  50  are formed, which as seen in circumferential direction oppose the edges of the recess  36  in an oblique alignment. Here as well, the blocking surfaces  50  form a V at the opposed carriers  34 , wherein the tip of the two Vs of the opposed carriers is directed towards the center of the recess  36 . 
         [0010]    The described synchronizing assembly operates in the following way: When a gear is to be engaged, for example the one which contains the transmission gear  14 , the transmitter  18  is shifted on the transmission shaft  10  in an axial direction by a means of a shift fork (not shown) in direction of the arrow P of  FIG. 1 . In a first step, which is called pre-synchronization, the two synchronizer rings  30  are carried to the left by the thrust pieces  42 , more exactly by the pre-synchronizing surface  46  of the thrust piece  42  engaging the left pre-synchronizing bevel  48  of the left synchronizer ring  30 , so that the synchronizer ring  30  gets into frictional engagement with the friction surface  32 . 
         [0011]    The speed of the transmission shaft  10  usually does not correspond to the speed of the transmission gears so that there is a speed difference between the synchronizer ring  30  and the friction surface  32 . This results in the synchronizer ring being carried along in circumferential direction (see the arrow U in  FIG. 8 ), whereby the blocking surface  50  gets in contact with the upper edge of the recess  36  as shown in  FIG. 8 . Due to the oblique alignment of the blocking surface  50 , there is produced a force component which prevents shifting of the transmitter disk  20  relative to the earner  34 ; as long as a speed difference exists, the resulting friction moment leads to the fact that the blocking surface  50  remains pressed against the edge of the recess  36 . The synchronizer ring supports on the friction surface  32  and cannot be shifted further in an axial direction. 
         [0012]    The blocking force exerted by the blocking surface  50  only decreases when the speed difference is decreased, so that the edge of the recess  36  of the transmitter disk  20  can shift the blocking surface  50 , due to its oblique alignment, in circumferential direction opposite to the direction of the arrow U, which provides for shifting through the transmitter. At the same time, the thrust pieces  42  are compressed downwards by the obliquely attached pre-synchronizing bevels  48  against the action of the spring  44 . The transmitter thereby can axially be shifted to such an extent that the external toothing  24  of the clutch disk  22  engages into the transmission gear toothing  16  associated with the transmission gear  14 , in this way, a rotationally fixed connection between the transmission shaft  10  and the transmission gear  14  to be engaged is produced. 
         [0013]    In contrast to the illustrated embodiment it also is sufficient when a blocking chamfer defined exactly in terms of length and angle is present only at one components for example. A complementary chamfer at the opposed component, e.g. transmitter, is advantageous for a full contact with the blocking chamfers. In principle, one of the two chamfers for example might also be omitted or be designed crowned. 
         [0014]    For releasing the shifted gear, the transmitter  18  is shifted back into its neutral position in opposite direction, whereby the two synchronizer rings  30  also are again set back into a neutral position. In this position, the fractional engagement with the friction surfaces  32  is eliminated. 
         [0015]    It is the object underlying the invention to develop the known synchronizing assemblies to the effect that a more compact construction is obtained. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0016]    In order to achieve this object, the invention provides a transmitter for producing a rotationally fixed connection between a transmission shaft and a transmission gear rotatably mounted on the same with a transmitter disk and a clutch disk associated with the transmitter disk. The transmitter includes a clutch disk external toothing, and the transmitter disk is provided with a transmitter toothing on its outside. The invention is based on the principle of forming one of the toothings, which previously were provided on the clutch disk, directly on the transmitter disk. Thus, the transmitter toothing is located outside the synchronizer rings, which provides for a shorter installation space in an axial direction. 
         [0017]    According to one aspect of the invention it is provided that the transmitter toothing is arranged on the outer circumference of the transmitter disk. This results in the shortest possible construction in an axial direction since the transmitter toothing coincides with the transmitter disk as seen in an axial direction. 
         [0018]    It can furthermore be provided that two synchronizer rings are mounted on the transmitter disk. The attachment of the synchronizer rings and the necessary design of the transmitter disk remain unchanged, which results in a small constructional effort as compared to the previously known construction of the transmitter. 
         [0019]    Preferably, it is provided that an actuating element is coupled to the transmitter disk in an axial direction. The actuating element provides for shifting the transmitter disk in an axial direction without having to engage the outer circumference of the transmitter disk, as has been necessary so far. 
         [0020]    According to one aspect if is provided that the clutch toothing is provided on a clutch disk which is associated with the transmitter disk. This provides for forming the transmitter disk as flat component, in particular as stamped sheet-metal component, since the clutch toothing is provided on a separate component. 
         [0021]    Preferably, it is provided that the clutch disk is arranged on a front side of the transmitter disk and is connected with the same in an axial direction, it is not necessary that the clutch disk is non-rotatably connected with the transmitter disk such that the torque between transmission shaft and engaged transmission gear is transmitted via the clutch disk and the transmitter disk; it is sufficient to connect the clutch disk with the transmitter disk such that the clutch disk follows the axial movements of the transmitter disk. The torque can be transmitted from the clutch toothing directly to the transmission shaft, in that the clutch disk is provided with a toothing on its inside which engages into a complementary toothing of the transmission shaft. 
         [0022]    The above-mentioned object is also achieved according to the invention by means of an assembly with a transmission shaft, at least one transmission gear rotatably mounted on the same and a transmitter as mentioned above, wherein the transmission gear is provided with a transmission gear toothing with which the transmitter toothing can be brought in engagement. With the transmitter according to the invention, two transmission gears furthermore can be coupled with the gear shaft, wherein the torque is transmitted from the transmission shaft to one of the transmission gears via the clutch disk and to the other transmission gear via the transmitter disk. This provides for arranging the transmission gears closer to each other in an axial direction. 
         [0023]    According to one aspect of the invention it is provided that an actuating element engages the transmitter disk, which proceeding from the transmitter disk extends in an axial direction. This actuating element leaves the installation space around the transmitter toothing empty, so that no allowance must be made for an installation space for actuation of the transmitter disk. 
         [0024]    The actuating element can extend around the transmission shaft in the manner of a sleeve. This results in a small constructional effort. 
         [0025]    Alternatively it can be provided that the actuating element is arranged within the transmission shaft. This provides for actuating the transmitter also when it is difficult to access on the outside in an axial direction, for example because it is arranged between several pairs of transmission gears. 
         [0026]    Preferably it is provided that the actuating element is coupled with the transmitter disk through an opening in the transmission shaft. For this purpose a small window is sufficient, by which the transmission shaft is not substantially weakened. 
         [0027]    According to one aspect of the invention it is provided that the transmission gear is provided with a transmission gear toothing with which the transmitter toothing can be brought in engagement. This results in a direct torque transmission from the transmitter disk to the corresponding transmission gear. 
         [0028]    The transmission gear toothing can be designed integrally with the transmission gear. The costs for the assembly of a separate component thereby are avoided. 
         [0029]    Alternatively it can be provided that the transmission gear toothing is provided on the inner circumference of a transmission gear toothed washer, which is non-rotatably connected with the transmission gear. This provides for producing the transmission gear toothing on a sheet-metal component to be manufactured at low cost, for example by stamping, which subsequently (possibly after a hardening operation) is connected with the transmission gear. 
         [0030]    According to one aspect it is provided that the transmission gear is provided with a friction surface which can cooperate with a synchronizer ring. This provides for maintaining the previously known construction as far as possible, so that only little modifications are necessary. 
         [0031]    Preferably, the friction surface is provided directly on the transmission gear. This reduces the number of components necessary altogether. 
         [0032]    The friction surface can be directed radially to the outside. It can also be provided that the friction surface is directed radially to the inside. This can be chosen optimally in dependence on the respective marginal conditions. 
         [0033]    According to one aspect of the invention it is provided that the friction surface is arranged radially within the transmission gear toothing. This results in a compact construction in an axial direction. 
         [0034]    The above-mentioned object is furthermore achieved according to the invention by means of a transmission with an assembly as mentioned above, wherein the transmission includes a housing which is provided with a blocking toothing with which the transmitter toothing can be brought in engagement in this aspect, the transmitter disk is used to produce a rotationally fixed connection between the transmission shaft and the housing of the transmission, so that the transmission is blocked for example in a parking position. For the function of the parking brake, other than in embodiments used for synchronizing, no synchronizer ring is necessary on the side of the transmitter disk on which the engagement with the transmission housing is effected. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0035]    Use invention will be described below with reference to various embodiments which are shown in the attached drawings, in which: 
           [0036]      FIG. 1  in a section schematically shows a synchronising assembly known from the prior art; 
           [0037]      FIG. 2  in an exploded view shows the synchronizing assembly of  FIG. 1 ; 
           [0038]      FIG. 3  in a perspective view shows a transmitter with synchronizer rings mounted thereon; 
           [0039]      FIG. 4  in a perspective view shows the synchronizer rings of  FIG. 3 ; 
           [0040]      FIG. 5  in a perspective view shows the transmitter of  FIG. 3 ; 
           [0041]      FIG. 6  shows a section along the plane VI-VI of  FIG. 1 ; 
           [0042]      FIG. 7  shows a section along the plane VII of  FIG. 6 ; 
           [0043]      FIG. 8  shows a section along the plane VIII of  FIG. 6 ; 
           [0044]      FIG. 9  in a section schematically shows a part of a transmission according to a first embodiment of the invention; and 
           [0045]      FIG. 10  in a view corresponding to the one of  FIG. 8  shows a second embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0046]    With reference to  FIG. 9  a first embodiment of a transmitter according to the invention now will be described. For the components which are known already from  FIGS. 1 to 8  the same reference numerals are being used, and in so tar reference is made to the above explanations. 
         [0047]    The essential difference between the assembly as it is shown in FIG. S and the assembly known from  FIGS. 1 to 8  is that the torque transmission between the transmitter disk  20  and one of the transmission gears (here the transmission gear  12 ) is not effected via a clutch disk with clutch disk toothing, but by a transmitter toothing  25  formed on the transmitter disk  20 . 
         [0048]    The transmitter toothing  25  here is provided directly on the transmitter disk  20 , namely in the form of teeth on the outer circumference of the transmitter disk. 
         [0049]    The transmitter disk  20  with the transmitter toothing  25  can be formed as flat component for example of sheet metal which is stamped. 
         [0050]    A further difference between the transmitter disk  20  used in the embodiment according to  FIG. 9  and the transmitter disk known from  FIGS. 1 to 8  is that in the embodiment according to  FIG. 8  the transmitter disk is provided with a transmitter disk internal toothing  21 . Similar to the clutch disk internal toothing  26 , the same non-rotatably, but axially shiftably engages into the transmission shaft toothing  28 . 
         [0051]    On the transmission gear  12  a transmission gear toothing  60  is provided, with which the transmitter toothing  25  can be brought in engagement. The transmission gear toothing  80  here is provided on a transmission gear toothed washer  62  which is non-rotatably connected with the transmission gear  12 , for example by welding. 
         [0052]    The transmission gear toothed washer  62  can be a stamped sheet-metal component, which possibly is hardened at least in the region of the transmission gear toothing  60 . 
         [0053]    Alternatively, it is also possible to form the transmission gear toothing  60  Integrally with the transmission gear  12 . 
         [0054]    In the embodiment shown in  FIG. 9 , the transmitter disk  20  also carries two synchroniser rings  30 ,  31 . In contrast to the embodiment shown in  FIGS. 1 to 8 , the two synchronizer rings however have a different geometry. The synchronizer ring  30  slightly Hares conically to the outside proceeding from the transmitter disk  20  so that it can be pushed onto the conical friction surface  32  directed to the outside, which is provided on the component  17 . The synchronizer ring  31  on the other hand tapers in an axial direction away from the transmitter disk  20  so that it can be pushed into a conical friction surface  33  directed radially to the inside, which is formed on the transmission gear  12 . 
         [0055]    The friction surface  33  here is formed as shoulder on the transmission gear  12 , i.e. integrally with the same. In principle, however, it also is possible to form a separate component on the transmission gear  12 , on which the friction surface then is provided. 
         [0056]    The transmitter disk  20  is engaged by an actuating element  70  with which the transmitter disk  20  can be shifted on the transmission shaft  10  in an axial direction. The actuating element  70  performs the function of a shift fork which in the embodiment according to  FIGS. 1 to 8  engages the outside of the transmitter disk  20 , in order to shift the same in an axial direction. 
         [0057]    In the embodiment according to  FIG. 9 , the actuating element  70  is designed in the manner of a sleeve which surrounds the transmission shaft  10 . The actuating element  70  engages the transmitter disk  20  with a flange  72  which is arranged at the point where the second clutch disk  22  is arranged in the embodiment according to  FIGS. 1 to 8 . 
         [0058]    With regard to the mode of operation during synchronizing and shifting gears, the embodiment according to  FIG. 9  does not differ from the embodiment according to  FIGS. 1 to 8 . When the transmitter disk  20  is actuated in one direction proceeding from the neutral position (see the arrow S), the two synchronizer rings  30 ,  31  are carried along in the corresponding direction. The synchronizer ring located “at the front” in shifting direction gets in engagement with the corresponding friction surface  32 ,  33 , and the process of synchronizing starts. When the speeds of the transmission shaft and the corresponding transmission gear  12 ,  14  are adapted to each other, the transmitter disk  20  can be shifted through, so that either when the transmission gear  12  is shifted, the torque is transmitted from the transmission shaft  10  via the transmitter disk internal toothing  21 , the transmitter disk  20 , the transmitter toothing  25  and the transmission gear toothing  60  to the transmission gear  12 , or when the transmission gear  14  is shifted, the torque is transmitted from the clutch disk internal toothing  26  via the clutch disk  22  and the clutch toothing  24  to the component  17  and from the same to the transmission gear  14 . 
         [0059]    The advantage of the embodiment according to  FIG. 9  as compared to the embodiment according to  FIGS. 1 to 8  is in particular that a more compact construction is possible in an axial direction. As can be seen in  FIG. 9 , the teeth of the transmission gear  12  can be arranged very close to the transmitter disk  20  in an axial direction. In the embodiment shown, the running teeth of the transmission gear  12  protrude beyond the transmitter disk  20 . This is possible because the arrangement of the transmission gear toothing and the friction surface on the transmission gear are interchanged as compared to the embodiment according to  FIGS. 1 to 8 . The friction surface  33  on the transmission gear  12  is arranged radially within the transmission gear toothing  60 , and the transmission gear toothing  60  is arranged closer to the transmitter disk than the friction surface  33 . 
         [0060]    It is not absolutely necessary to couple the actuating element  70  laterally within the synchronizer rings  30 ,  31 . It might also be provided that radially outside the synchronizer rings  30 ,  31  on the side of the transmission gear  14  an add-on part is provided al the transmitter disk  20 , with which laterally of the transmitter toothing  25  a groove or a circumferential edge is formed so that a sliding block or a shift fork can engage there. 
         [0061]      FIG. 10  shows a further embodiment. For the components known from the preceding embodiments the same reference numerals are used, and in so far reference is made to the above explanations. 
         [0062]    The difference between the embodiment according to  FIG. 10  and the embodiment according to  FIG. 9  is that in the embodiment according to  FIG. 10  the transmitter merely engages one transmission gear (here the transmission gear  14 ). When the transmitter disk  20  is shitted to the right proceeding from the neutral position shown in  FIG. 10 , it gets in engagement with a blocking toothing  80  provided on a housing  82  of the transmission, in which the transmission shaft  10  is mounted. 
         [0063]    The blocking toothing  80  here is designed integrally with the housing  82 . It also is possible to provide the blocking toothing  80  similar to the transmission gear toothing  60  in the embodiment according to  FIG. 9  on a separate component which then is mounted on the housing  82 . 
         [0064]    A further difference between the embodiment according to  FIG. 10  and the embodiment according to  FIG. 9  is that in the embodiment according to  FIG. 10  the actuating element  70  is arranged within the transmission shaft  10 . It is provided with an actuating tab  74  which extends axially to the outside through an opening  76  in the transmission shaft  10  and is connected with the transmitter disk  20 . 
         [0065]    In the embodiment according to  FIG. 10  a friction surface  32  is provided on the housing  82 , which in the same way as the friction surface  32  on the component  17  is directed radially to the outside. Thus, two synchronizer rings  30  with identical geometry can be arranged on the transmitter disk. 
         [0066]    When the transmitter disk  20  in the embodiment according to  FIG. 10  is shifted to the left starting from the illustrated neutral position, a shifting operation is effected in a known way with the transmission gear  14 . When the transmitter disk  20  however is shitted to the right, a kind of synchronizing operation is effected, which leads to the fact that the speed of the transmission shaft  10  is brought to zero until finally the transmitter disk  20  can be shifted through. The transmission shaft  10  thereby is non-rotatably blocked in the housing  82  via the transmission shaft toothing  28 , the transmitter disk internal toothing  21 , the transmitter toothing  25  and the blocking toothing  80 . 
         [0067]    According to a non-illustrated development, the actuating element  70  arranged within the transmission shaft also can be used in the embodiment according to  FIG. 9 , in which two transmission gears are shifted with the transmitter disk. Conversely, the sleeve-like actuating element  70  known from the embodiment of  FIG. 9  also can be used in the embodiment according to  FIG. 10 , in which the transmitter disk can be brought in engagement with the blocking toothing  80 . 
         [0068]    Furthermore, in the embodiment according to  FIG. 9  there can also be used a friction surface  32  directed radially to the outside, as it is used in the embodiment according to  FIG. 10 . Conversely, in the embodiment according to  FIG. 10  a friction surface  33  directed radially to the inside can be used on the side of the housing  82 , as it is known from the embodiment according to  FIG. 9 .