Abstract:
The invention relates to a planetary gearbox comprising at least one sun gear ( 17, 18 ) and at least one planet carrier ( 5 ) arranged coaxially with and rotatably in relation to said gear, a combination of a bearing sleeve ( 40 ) and a slide ring ( 41 ) that is separate therefrom being located between the sun gear ( 17, 18 ) and the planet carrier ( 5 ). The invention also relates to a gearbox combination of a differential of the spur-gear differential type, in the form of which the planetary gearbox is configured, and an additional planetary stage, the spur-gear differential and the planetary stage preferably having a common planet carrier ( 5 ) composed of multiple planet sub-carriers ( 6, 7, 8 ) that are non-rotatably combined.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is the U.S. national stage application pursuant to 35 U.S.C. §371 of International Application No. PCT/EP2013/056653, filed Mar. 28, 2013, which application claims priority from German Patent Application Nos. DE 10 2012 208 799.0, filed May 25, 2012, and DE 10 2012 208 805.9, filed May 25, 2012, 25, 2012, which applications are incorporated herein by reference in their entireties. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates generally to a planetary drive with at least one sun gear and at least one coaxially arranged planetary carrier arranged rotationally thereat. 
       BACKGROUND 
       [0003]    An example of a known planetary drive is shown in German Patent Application No. DE 10 2009 032 286 A1. The disclosed planetary drive has two sun gears with each sun gear engaging a set of planetary gears, which are supported by a planetary carrier. The sun gears are radially centered by the force of gears during operation when the planetary gears are engaged. Unfortunately, the centering of the sun gears during the unloaded state is not sufficiently ensured, if ensured at all. Without sufficient centering, the sun gears can become displaced far away from the central radial position. Additionally, imbalances can develop at the sun gears during operation, despite the applied gear forces. Furthermore, misalignments are possible between the sun gear and the planetary carrier. This leads to increased wear and tear and increased noise development. These problems apply even more when strong forces are transferred between the planetary gears and the sun gears, such as is transferred in a differential. 
         [0004]    Examples of typical transmission combinations are shown in German Patent Application No. DE 10 2008 027 992 A1. A drive device for transverse installation into motor vehicles with all-wheel drive is disclosed. The drive device is provided for transverse installation, in which the axial differential and an interim axial differential are structurally combined in one transmission housing. The differentials are spur gears, showing a first bar as an input element of the interim axial differential, which drives the sun wheel as one output element, and, via an exterior wheel the axial differential as the other output element, with the exterior wheel via the bar of the axial differential and its planetary gears driving the output elements towards the axial shafts. This publication teaches that the two differentials are embodied with regard to transmission technology such that they show a common bar. A spur differential and a planetary gear as the transmission stage are thus combined. Unfortunately, torque is deducted via the superimposed stage from a front axle to a rear axle differential of the motor vehicle in this publication. 
         [0005]    A typical planetary gear is disclosed in U.S. Pat. No. 4,574,658, in which a planetary gear is combined with a superposed spur gear stage. A sun gear of the planetary gear is driven via an additional spur gear section by a sprocket separated from the planetary gear. 
         [0006]    German Patent No. DE 2031654 A1 and United Kingdom Patent No. GB 1212630 A disclose transmission combinations in which different transmission stages are connected to each other. In particular, among other things, a non-rotatable connection is disclosed. The non-rotatable connection shows a transmission stage with two cooperating transmission elements, each respectively showing an annular element, which comprises an axially extending cylindrical projection and which forms a non-rotatable coupling together with the annular element of the other transmission element. The annular elements are made from sheet metal and show tooth-like indentations extending axially, which engage each other like partial gearing. 
         [0007]    Certain parts of planetary carriers can be welded to each other, as is described in German Patent Application Nos. DE 103 33 880 A1 and DE 103 33 879 A1. 
         [0008]    A typical transfer gearbox for a motor vehicle is disclosed in German Patent Application No. DE 10 2007 017 185 B4. The described transfer gearbox comprises a driven differential, which drives two shafts via compensation elements, with the possibility that the driven moment at the driven shafts can be changed by a drive engine, formed by a planetary gear, drivingly connected to the driven shafts directly or indirectly via superimposed transmissions. The conversion of the superimposed transmission is designed such that, during synchronized operation of the driven shafts, the driving engine is stationary. This publication suggests positioning one planetary gear upstream relative to the superimposed transmission for it to cooperate with the differential and reduce the moment. Positioning a planetary gear as such is described as improving the redistribution with respect to precision, and providing a more rapid reaction with respect to the driven moments. 
         [0009]    Unfortunately, typical planetary gears and transmission combinations comprise a large number of components and require an abundance of structural space. The production of typical planetary gears and transmission combinations thus leads to relatively high costs and the assembly is relatively expensive. 
       SUMMARY 
       [0010]    According to aspects illustrated herein, there is provided a planetary drive, comprising a sun gear; a planetary carrier operatively arranged coaxially and rotatably with respect to the sun gear; and, a support component located radially between the sun gear and the planetary carrier, the support component comprising a bearing sheath and a gliding ring. 
         [0011]    According to aspects illustrated herein, there is provided a transmission combination comprising a differential gear embodied as a spur differential, and an additional planetary stage, with the spur differential and the planetary stage having a common planetary carrier assembled in non-rotatably with respect to several partial planetary carriers. 
         [0012]    According to aspects illustrated herein, there is provided a planetary drive having a combination of a bearing sheath and a gliding ring, separated therefrom, located between the sun gear and the planetary carrier. This allows the wear and tear to be considerably reduced. Tolerances can be particularly well compensated, here, when the gliding ring shows an elastic section, allowing a deformation in its diameter. 
         [0013]    An objective of the present disclosure is to avoid the disadvantages of the prior art and to allow a better spatial utilization with lower costs and a simpler assembly. Further, the resistance to wear and tear shall be improved. 
         [0014]    It is also advantageous for the elastic section to be embodied by an elastic bar, formed at the gliding ring by one or more recesses. The gliding ring can then be arranged with little radial pre-stressing between the sun gear and the planetary carrier. This way, the sun gear can be precisely centered and the axial distances between it and the planetary gears can be precisely predetermined. 
         [0015]    A gliding ring, variably adjustable with regards to its elastic effect, can be used in a particularly cost-effective fashion when the bar shows the form “Z”, i.e., is Z-shaped, with right angles in the circumferential direction. Here, the recesses develop, which are advantageous for the distribution of lubricant and the flow through at the gliding ring. In particular when the gliding ring is stationary these recesses serve as a reservoir for lubricant, in which said lubricant can collect in order to be redistributed during operation, particularly at the gliding area. This leads to a homogenous distribution of the lubricant. 
         [0016]    The assembly can be facilitated when the gliding ring is inserted in the bearing sheath like a latching spring. 
         [0017]    The costs can also be kept low during production, when the bearing sheath is produced from sheet metal and preferably surrounds, e.g., circumscribes, the gliding ring. 
         [0018]    When the gliding ring is located between two bulges of the bearing sheath extending radially inwardly, here an axial fixation of the gliding ring can be realized in reference to the bearing sheath, which is beneficial for the functionality. 
         [0019]    The present disclosure also relates to a transmission combination comprising a differential gear like a spur differential, as explained above, and an additional planetary stage, with the spur differential and the planetary stage preferably showing a common planetary carrier assembled in a non-rotatable fashion from several partial planetary carriers. 
         [0020]    It is further advantageous for the surface area in the proximity of the hole for a planetary bolt to be post-processed in a cutting fashion, preferably milled. 
         [0021]    It has also shown to be particularly space-saving when the differential gear is embodied as a spur gear differential, which shows several planetary gears engaging each other, with respectively a first planetary gear engaging a first sun gear and the other, second planetary gear engaging the second sun gear, with both planetary gears and two partial planetary carriers of the planetary carrier being supported in a rotational fashion and/or the first planetary gear showing a greater axial length than the second planetary gear. Particularly in an embodiment of the planetary gears with different lengths, here a very compact design can be realized. 
         [0022]    When the planetary gear is supported on bolts, which rest in at least two partial planetary carriers, preferably via hardened sheaths, here an expensive hardening of the bolts can be waived and more cost-effective bolts can be used. The sheaths formed from sheet metal may be hardened in a cost-effective fashion before they are installed. 
         [0023]    When a bolt embodied as a connecting bolt is located in the two exterior partial planetary carriers, which preferably supports on one side a planetary gear of the spur differential and on the other side a planetary gear of the planetary stage, here the number of bolts can be reduced, which in turn is beneficial for the assembly. 
         [0024]    It is further beneficial for the connecting bolts to be guided through the hole, which is surrounded by the surface area post-processed by way of milling, which forms a contact area for a disk, preferably embodied in a hardened fashioned, with which the disk can be made to contact a planetary gear of the planetary stage. The construction space can then be used particularly efficiently and any wear and tear can be reduced which occurs when a planetary gear of the superimposed stage comes into contact with the central partial planetary carrier. 
         [0025]    It is also beneficial when the bolt embodied as a carrying bolt is arranged in the central partial planetary carrier and the exterior partial planetary carrier, distanced from the added planetary stage, in a recess embodied preferably as a penetrating hole. While the narrower of the two planetary gears on the spur differential and one planetary wheel of the additional planetary stage are arranged on the connecting bolt, the wider of the two planetary gears of a set of planetary gears of the spur differential can be supported exclusively on the supporting bold and thus an advantageous distribution of forces can be yielded. 
         [0026]    An advantageous exemplary embodiment is also characterized in that the penetrating hole is surrounded by a bead extending axially in the direction of the additional planetary stage. The forces developing during the operation of the transmission combination can then be compensated in a particularly effective fashion. 
         [0027]    In order to prevent that any interaction of the planetary gear of the additional planetary stage can occur upon the bead it is advantageous for the bead, completely surrounding the penetrating hole, to be distanced from the post-processed surface area of the neighboring hole, preferably distanced by more than one tenth or one fifth of the diameter of the penetrating hole. 
         [0028]    It is also beneficial for a radially projecting gearing to be embodied at the exterior of the planetary carrier. 
         [0029]    Further, it is advantageous for the gearing to be embodied as an exterior gearing on one of the partial planetary carriers and/or the exterior gearing to be embodied as a helical gearing or as spur gearing, preferably as parking-lock gearing. Particularly when the exterior gearing is embodied as parking-lock gearing, a linking locking element, such as a parking brake, can engage the exterior gearing and completely block the transmission so that any moving of the motor vehicle, in which the transmission combination and/or the planetary gear is used, is no longer possible. In many countries particularly such a parking-lock gearing is necessary to fulfill statutory stipulations. Such a parking-lock gearing shall be embodied such that the counterpart of the parking-lock gearing, for example a parking-lock provided with links, can engage the parking-lock gearing in a preferably locking fashion at  6  km/h and cannot engage at higher speeds, in a particular exemplary embodiment. When a helical gearing is provided, a driving moment can also be applied upon the planetary carrier. In general, however, the spur gearing is preferred, particularly in an embodiment as a parking-lock gearing. 
         [0030]    It is also advantageous when a planetary carrier embodied from several parts comprises three or more partial planetary carriers. This way the assembly can be simplified. 
         [0031]    It is also beneficial for a central partial planetary carrier, arranged between two exterior partial planetary carriers, to show an exterior gearing. Any symmetric distribution of forces and torque can then easily be realized. 
         [0032]    The lifespan is extended if the partial planetary carrier showing an exterior gearing is embodied massive, as a cast part, or as a forged part. In such a case the parking-lock gearing can be easily integrated, for example by a cutting process. An alternative to such a partial planetary carrier produced from sheet metal is also possible. 
         [0033]    It is also possible for the second planetary gear to be supported via a bolt, which extends from one exterior partial planetary carrier through the partial planetary carrier comprising the exterior gearing to the other exterior partial planetary carrier. The non-rotatable connection is here improved and the assembly is simplified. 
         [0034]    It is also advantageous when two of the partial planetary carriers, with preferably one of the partial planetary carriers being provided with exterior gearing, form a housing for at least the differential gear or the entire transmission combination. 
         [0035]    The capacity of the transmission combination can also be increased when a central partial planetary carrier located between the two exterior partial planetary carriers shows a curved shaped bar, inserted in a hole of one of the two exterior partial planetary carriers, embodied in a matching fashion. 
         [0036]    It is also beneficial for the section of the bar inserted in the hole to be processed sectionally in a cutting fashion, preferably at the interior and the exterior. 
         [0037]    The stability is here increased particularly when the exterior partial planetary carrier showing the hole is welded to the partially planetary carrier showing the bar, in the area of said bar. 
         [0038]    The production can be implemented in a particularly cost-effective fashion when the partial planetary carrier comprising the hole is embodied as a sheet metal part, preferably as an annular partial planetary carrier plate. 
         [0039]    Particularly when the partial planetary carrier plate shows holes, embodied as slots and distanced from each other with identical angles, the respective introduction of force can be embodied symmetrically, preventing any imbalances and extending the life span. 
         [0040]    Here, it is advantageous for the partial planetary carrier plate to be a part of the additional planetary stage. 
         [0041]    It is also advantageous for the central partial planetary carrier to be riveted to an exterior partial planetary carrier, preferably representing a part of the differential gear, with further preferred always two rivets each being located in one of several recesses, with the recesses being provided at the side of the central partial planetary carrier, facing the partial planetary carrier showing the hole. The stability of the transmission combination increases, and utilization with less maintenance can be realized. 
         [0042]    Further it is advantageous when three bag-like recesses are provided at the central partial planetary carrier and at the exterior partial planetary carrier connected thereto, in which two rivets each are located axially without projecting. 
         [0043]    Further it is advantageous when a bearing sheath is inserted between at least one sun gear and one planetary carrier such that it axially and/or radially impacts the sun gear, supporting it in reference to the planetary carrier. 
         [0044]    Particularly when the bearing sheath is inserted in an exterior partial planetary carrier, which represents a part of the differential gear, for the axial and/or radial positioning of a spur gear, such as a sun gear, the wear and tear is reduced. 
         [0045]    When the bearing sheath shows at least one radial and/or axial bulging here the sun gear can be precisely positioned in reference to one of the exterior partial planetary carriers. 
         [0046]    Here it is advantageous when the bearing sheath configured as a sheet metal part is inserted radially in the exterior partial planetary carrier in a force-fitting fashion, preferably impressed. The bearing sheath is then mounted in a consistent position in the exterior partial planetary carrier, which has reducing effects upon the play. 
         [0047]    In order to increase the life span it is advantageous for the bulging to be embodied hardened at least sectionally, with the bearing sheath preferably further showing elastic spring features at least in partial sections. 
         [0048]    It is also beneficial for the bulging of the bearing sheath to be provided with a first hardened section, extending axially in the direction of the two sun gears, and/or with a second hardened section, which extends radially inwardly, and/or a third hardened section is provided at the bearing sheath, which is axially distanced from the second hardened section and is located at the side of the second hardened section distanced from the sun gear. When a third hardened section is provided, the safety from the sun gear tipping is increased, with the first and the second hardened section on the one side performing an axial securing function and on the other side a radially securing function. 
         [0049]    This tipping safety of the bearing sheath in turn is improved when the bearing sheath shows a support section extending from the bulging radially towards the outside, which contacts the exterior partial planetary carrier. 
         [0050]    When one planetary gear each of a pair of planetary gears is shorter than the other planetary gear of said pair and preferably a friction disk is arranged between the sun gears, a particularly compact embodiment of the device develops and the desired blocking effect can be adjusted. 
         [0051]    Planetary carriers made from thick sheet metal lead to relatively large deformation radii. The leading portion of the sun gears is thereby reduced. For compensation, here only one torque angle gauge with a bulging bead is provided, which allows greater support width. Additionally, the disk is hardened, and therefore shows better wear and tear features. 
         [0052]    The present disclosure also relates to a drive train of a motor vehicle, such as a passenger vehicle, a truck, or a tractor, comprising a transmission combination according to the present disclosure as explained above. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0053]    Various embodiments are disclosed, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, in which: 
           [0054]      FIG. 1  is a perspective view of a transmission combination according to the invention from the side of a differential gear; 
           [0055]      FIG. 2  is a perspective view of the transmission combination of  FIG. 1  from the side of an additional planetary stage; 
           [0056]      FIG. 3  is a central partial planetary carrier as installed in the transmission combination of  FIGS. 1 and 2 , in a perspective view from the side of the differential gear; 
           [0057]      FIG. 4  is the central partial planetary carrier of  FIG. 3  in a perspective view from the side of the additional planetary stage; 
           [0058]      FIG. 5  is a longitudinal cross-section through the transmission combination of the exemplary embodiments of  FIGS. 1 and 2 ; 
           [0059]      FIG. 6  is an enlarged illustration of the connection area between two partial planetary carriers in the area of the differential gear of the transmission combination of  FIG. 5 ; 
           [0060]      FIG. 7  is a longitudinal cross-section through a transmission combination as illustrated in  FIGS. 1 ,  2 , and  5 , in a level, in which a narrow planetary gear of the differential gear and a planetary gear of the additional planetary stage are located; 
           [0061]      FIG. 8  is a perspective, partially cross-sectioned illustration of the transmission combination of  FIG. 7 ; 
           [0062]      FIG. 9  is a longitudinal cross-section of the transmission combination shown in  FIGS. 1 ,  2 ,  5 , and  7 , however in a level in which only one wide planetary gear of the differential gear is located; 
           [0063]      FIG. 10  is a partially cross-sectioned, perspective illustration of the transmission combination of  FIG. 9 ; 
           [0064]      FIG. 11  is a view from the differential gear side to the transmission combination as shown in  FIGS. 1 ,  2 ,  5 , and  7  to  10 ; 
           [0065]      FIG. 12  is a transmission combination of  FIG. 11  in a view from the side; 
           [0066]      FIG. 13  is a view of the transmission combination of  FIG. 11  from the side of the additional planetary stage; 
           [0067]      FIG. 14  is an exploded illustration of the transmission combination of  FIGS. 1 ,  2 ,  5 , and  7  to  13 ; 
           [0068]      FIG. 15  is a longitudinal cross-section of a part of the transmission combination with a bearing sheath located between a sun gear and an exterior partial planetary carrier; 
           [0069]      FIG. 16  is an enlarged illustration of an area in which the bearing sheath of the exemplary embodiment is located according to  FIG. 15 ; 
           [0070]      FIG. 17  is another enlarged illustration of the section of the transmission combination, in which the bearing sheath is located; 
           [0071]      FIG. 18  is a perspective illustration of a variant of a bearing sheath for the transmission combination of  FIG. 1 ; 
           [0072]      FIG. 19  is a perspective illustration of a variant of a bearing sheath for the transmission combination of  FIG. 1 ; 
           [0073]      FIG. 20  is a cross-section through a part of the transmission combination with an installed alternative bearing sheath; 
           [0074]      FIG. 21  is an enlarged illustration of a cross-sectioned alternative bearing sheath of the exemplary embodiments as inserted in  FIGS. 18 to 20 ; 
           [0075]      FIG. 22  is a perspective illustration of a variant of a transmission combination according to the invention with an installed bearing sheath; 
           [0076]      FIG. 23  is a cross-sectional illustration through a variant of a transmission combination in the area of a bearing sheath between one of the sun gears and the exterior partial planetary carrier, with additionally a gliding ring being located between the bearing sheath and an axial flange area of the sun gear; 
           [0077]      FIG. 24  is a perspective illustration of the gliding ring only, as used in the exemplary embodiment according to  FIG. 23 ; 
           [0078]      FIG. 25  is a cross-sectional illustration of the gliding ring of  FIG. 24  installed in a bearing sheath; 
           [0079]      FIG. 26  is a perspective illustration of the bearing sheath and the gliding ring only; and, 
           [0080]      FIG. 27  is a longitudinal cross-section of the gliding ring of  FIG. 24 . 
       
    
    
       [0081]    The figures are only of a schematic nature and merely serve for understanding the invention. 
       DETAILED DESCRIPTION 
       [0082]    At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the disclosure. It is to be understood that the disclosure as claimed is not limited to the disclosed aspects. 
         [0083]    Furthermore, it is understood that this invention is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present disclosure. 
         [0084]    Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. It should be understood that any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure. 
         [0085]    By “non-rotatably connected” first and second components we mean that the first component is connected to the second component so that any time the first component rotates, the second component rotates with the first component, and any time the second component rotates, the first component rotates with the second component. Axial displacement between the first and second components is possible. 
         [0086]    Referring now to the Figures,  FIG. 1  shows transmission combination  1 . Transmission combination  1  shows a section, which is differential gear  2  in an embodiment. An additional section of transmission combination  1  is embodied as planetary stage  3  complementing differential gear  2 . Differential gear  2  is embodied as a planetary gear, particularly as spur differential  4 . 
         [0087]    Transmission combination  1  comprises planetary carrier  5 , with exterior partial planetary carrier  6  being discernible, located in  FIG. 1  on the side of the differential gear. Another exterior partial planetary carrier  7 , which is a part of additional planetary stage  3 , though, is particularly clearly discernible in  FIG. 2 , in which the side of the planetary stage  3  is located in the foreground. 
         [0088]    Central partial planetary carrier  8  is provided between exterior partial planetary carrier  6  and exterior partial planetary carrier  7 . Planetary carrier  8  ultimately represents both differential gear  2  as well as planetary stage  3 . 
         [0089]    Exterior partial planetary carriers  6  and  7 , and central partial planetary carrier  8  are connected to each other to form planetary carrier  5 . Each of carriers  6 ,  7 , and  8  are secured to each other such that they are non-rotatable with respect to each other. 
         [0090]    At the exterior of planetary carrier  5 , namely embodied at central partial planetary carrier  8 , radially projecting gearing  10  is embodied on exterior  9  of planetary carrier  5  in the area of the largest diameter. In an embodiment, gearing  10  is spur-geared like a parking-lock gearing. In an embodiment, central partial planetary carrier  8  is a cast part or a forged part and is a massive part, which unlike exterior partial planetary carrier  7  of planetary stage  3 , is not embodied as a sheet metal part, but as a part formed by post-processing using cutting processes. 
         [0091]    A parking-lock engages gears  10  in the blocking state of transmission combination  1 . This parking-lock is not shown. Exterior partial planetary carrier  6  of differential gear  2  is connected with rivets  11  to central partial planetary carrier  8 . Here, recesses  12  are provided in the two partial planetary carriers  6  and  8 , in which two rivets  11  each are arranged, thereby securing partial planetary carrier  6  non-rotatably with respect to partial planetary carrier  8 . 
         [0092]    In an embodiment, differential transmission  2  is a spur differential, which shows several planetary gear pairs  13  at planetary gears  14  and  15 . First planetary gear  14 , contrary to second planetary gear  15 , shows a greater axial length. The axial length is measured along the rotary axis of transmission combination  1 . The different axial length of the two planetary gears  14  and  15  is clearly discernible in  FIG. 14 , among other things. 
         [0093]    In  FIG. 5 , from planetary gears  14  (shown in  FIG. 9) and 15  of differential gear part  2 , only second planetary gear  15  as well as two additional planetary gears  16  of the additional planetary stage  3  are discernible between central partial planetary carrier  8  and exterior partial planetary carrier  7  of planetary stage  3 .  FIG. 5  also shows the presence of two sun gears  17  and  18 , with sun gear  17  engaging first planetary gear  14 , and sun gear  18  engaging second planetary gear  15 . Planetary gears  14  and  15 , which make up planetary gear pair  13  (shown in  FIG. 14 ) of differential transmission part  2 , may also engage simultaneously. 
         [0094]    Second planetary gear  15  is also supported on bolt  19 . Bolt  19  is also called connecting bolt  20 . Connecting bolt  20  is located in hardened sheaths  21  in exterior partial planetary carriers  6  and  7 . Sheaths  21  also show radially projecting flanges  22 , which can be made to contact the respective planetary gears  15  and  16 . 
         [0095]    Hardened disk  23  is also provided at a radially interior end of central partial planetary gear  8 , which can be made to contact sun gear  17 . 
         [0096]    Sun gears  17  and  18  each have an interior gearing, which enables by which the elements for torque transmission can be brought into engagement with the wheels of a motor vehicle. Friction disk  24  is provided between sun gears  17  and  18 . Friction disk  24  can also be called a friction ring. 
         [0097]    Connecting bolt  20  may also show a longitudinal bore, which is connected to lateral bores, so that lubricant can be brought into an area between connecting bolt  20  and planetary gear  16 . This way e.g., oil can be supplied and the friction can be reduced. 
         [0098]    With regards to planetary stage  3 , embodied as a load stage, the respective hollow gear and sun gear embodiments are not shown. For example, the sun gear is usually embodied as a part connected to a hollow shaft. The hollow wheel in turn may also show a gearing at the exterior or may be rippled up with a geared flange part. 
         [0099]    As clearly discernible from  FIG. 5 , disk  25  is located between planetary gear  16  and central partial planetary carrier  8 , which can also be called a contact disk, preventing the wear and tear of central partial planetary carrier  8 , which otherwise would develop upon planetary gear  16  contacting central partial planetary carrier  8  during rotation. Accordingly, disk  25  acts in a supporting fashion similar to radially projecting flanges  22  of sheath  21 . Disk  25  can be hardened, similar to sheath  21 . 
         [0100]    Planetary gear  5  forms the housing of transmission combination  1  and could in its entirety also be called the bar. 
         [0101]    However, here a bar is understood as an axial extension of central partial planetary carrier  8  and is marked with reference character  26 . 
         [0102]    As particularly clearly discernible in  FIGS. 2 and 5 , here axial end  27 , which is preferably post-processed in a cutting fashion by way of milling on its radial inside  28  and its radial outside  29 , projects without play into hole  30  of exterior partial planetary carrier  7  embodied as a plate. Exterior planetary carrier  7  may also be called a partial planetary carrier plate, just as it here per se forms a planetary carrier plate. 
         [0103]    Bar  26  is welded to this partial planetary carrier plate and/or to exterior partial planetary carrier  7 . Here, an induction welding method is beneficial. 
         [0104]    Although by the welded connection between exterior partial planetary carrier  7  and central partial planetary carrier strong forces can be transferred on the one side, on the other side central partial planetary carriers  8  can also transfer strong forces upon exterior partial planetary carrier  6 , because a compact rivet form of rivet  11  is possible due to recess  12 . Rivet  11  and, accordingly, recess  12  are always allocated to bar  26 . Recess  12  is therefore arranged radially outside bar  26 , which has positive effects upon the ability to transfer forces. 
         [0105]    While in  FIGS. 1 and 2 , assembled transmission combination  1  is in the foreground, in  FIGS. 3 and 4 , only central partial planetary carrier  8  is in the foreground. Here, material recesses  32  are provided at side  31  of central partial planetary carrier  8  facing exterior partial planetary carrier  6 , in order to accept first planetary gears  14 . Material recesses  32 , here, convert to holes  33  and  34 , which are embodied as penetrating openings. Here, holes  33  and  34  are provided in order to accept bolts  19 . 
         [0106]    Here, connecting bolt  20  is inserted into hole  33 , with support bolt  35  being inserted into hole  34 . Support bolt  35  is a special embodiment of bolt  19  and carries only planetary gear  14 . At the other side, as shown in  FIG. 4 , thus the side of additional planetary stage  3 , hole  35  is surrounded by bead  36 . 
         [0107]    Hole  33  is surrounded by surface area  37  arranged concentric in reference thereto. In reference to surface  38  of central partial planetary carrier  8 , surface area  37  is axially offset in the direction of exterior partial planetary carrier  7 . This off-setting is ensured by a cutting processing, particularly by a milling process. Here, in general polishing and lapping methods are possible, too. 
         [0108]    In transmission combination  1 , three recesses  12  are each provided with two rivets  11 , three bars  26 , three holes  33 , and three holes  34 . These parts are evenly distributed in reference to a rotary axis of transmission combination  1 , not shown. However, holes  33  and  34  are not located on the same pitch diameter. It shall also be pointed out that the outside diameter of sun gears  17  and  18  are different. The outside diameter of the small sun gear is here smaller than the foot circular diameter of the large sun gear. This is caused by the small sun gear being 20% smaller than the large sun gear. In the traction mode the smaller planetary gear of pair  13  travels ahead of the large planetary gear. By the solution according to the invention, the noise emission is also reduced. Any problems arising with respect to the support width are also reduced. Even locking values up to 30% can be realized without major problems developing. This way, a so-called torsion differential can be generated. 
         [0109]    Bead  36  is distanced from surface area  37 , processed in a cutting fashion, by one-seventh of the diameter of hole  34 . Hole  33  may also be embodied as a blind hole. 
         [0110]    As clearly discernible in  FIG. 4 , bar  26  is curved in the circumferential direction. The section of bar  26  formed by axial end  27  is post-processed in a cutting fashion. 
         [0111]    With reference to  FIG. 13 , the matching curved embodiment of hole  30  is shown in exterior partial planetary carrier  7 . Here, hole  30  extends in the circumferential direction further than bar  26  so that, seen in the circumferential direction, cavities  39  develop at both sides of bar  36 . Holes  30  are embodied as circumferentially displaced slots, each having the same length in the circumferential direction. However, it is also possible that one of the slots is embodied longer than the other one. 
         [0112]    In general, it is also possible that exterior partial planetary carrier part  7 , in the exemplary embodiment shown here embodied as a sheet metal part, is not embodied as an annular partial planetary carrier plate but is also produced as a cast or forged part. 
         [0113]    While in  FIGS. 1-5  particularly also the gears  10  are discernible on the exterior of central partial planetary carrier  8 , in  FIG. 6  only the short embodiment of the rivets  11  is discernible, as inserted in the recesses  12  in order to secure central partial planetary carrier  8  in a non-rotable manner with respect to exterior partial planetary carrier  6 . 
         [0114]    As visualized in  FIGS. 5 and 7 , bearing sheath  40  is provided between sun gear  18  and exterior partial planetary carrier  6 . Bearing sheath  40  is also used in the exemplary embodiment according to  FIG. 9 . However, in the exemplary embodiment according to  FIG. 15 , a modified form of bearing sheath  40  is used. Bearing sheath  40  shown here is also used in the exemplary embodiment according to  FIG. 16 . This second embodiment of bearing sheath  40  is axially longer than bearing sheath  40  of the exemplary embodiments of  FIGS. 7 and 9 . The shorter bearing sheath here is also used in the exemplary embodiment of  FIGS. 17 to 22 , while the longer variant of bearing sheath  40  in turn is used in the exemplary embodiments of  FIGS. 23 ,  25 , and  26 . 
         [0115]    Gliding ring  41  is also used with the longer variant of bearing sheath  40 , as shown in the exemplary embodiment according to  FIGS. 23 to 27 . Together, bearing sheath  40  and gliding ring  41  form a support component. 
         [0116]    Before bearing sheath  40  and gliding ring  41  are discussed in greater detail it shall be pointed out that  FIGS. 7 and 8  show the support of planetary gear  16  and second planetary gear  15  on the very same bolt  19 , namely connecting bolt  20 . However, an illustration is selected in  FIGS. 9 and 10 , which discloses the bearing of support bolt  35 . Here, support pin  35  only carries the first planetary gear  14 . The entire assembly of transmission combination  1  can be particularly clearly seen in the completely assembled version of  FIGS. 11 to 13 . The adaptation of axial ends  27  of bars  26  in the respectively shaped holes  30  is here also clearly discernible. 
         [0117]    In the exemplary embodiment shown in  FIG. 14 , sheaths  21  are already assembled in exterior partial planetary carrier  6 , exterior partial planetary carrier  7 , and central partial planetary carrier  8 . The different axial length of connecting bolts  20  in reference to support bolt  35  is such that support bolt  35  is approximately half the length of connecting bolts  20 . In order to support the individual planetary gears  15  and  16  here the use of hardened disks  23  and rings  42  is also beneficial, with rings  42  also potentially being hardened. 
         [0118]    Bearing sheath  40 , as shown in  FIGS. 15 and 17 , is embodied such that it acts axially and radially supporting sun gear  18  and holds it axially and radially distanced from exterior planetary carrier  6 . For this purpose the bearing sheath  40  shows at least one bulging  43 , which is located between support area  44 , radially projecting outwardly, and an axially aligned contact area  45 . Bearing sheath  40  is located in contact area  45  in a compressed connection with exterior partial planetary carrier  6 . 
         [0119]    Bulging  43  shows first hardened section  46 , which extends in the axial direction, as well as second hardened section  47 , arranged at a right angle in reference thereto, which extends in the radial direction. 
         [0120]    Distanced from first hardened section  46  by the axially aligned contact area  45 , third hardened section  48  is given in the area of securing section  49 , extending in the axial direction and radially off-set inwardly. 
         [0121]    For shaping hardened sections  46 ,  47 ,  48  an induction curing method is recommended. However, carburization is also possible, in general. 
         [0122]    As shown in  FIG. 16 , in the area of the bulging  43  and the securing section  49  two axially distanced radial bearing sections of the bearing sheath  40  are formed in reference to the sun gear  18 . Additionally, an axial bearing section is formed. The bearing sheath  40  can show at least sectionally elastic features in order to compensate tolerances and damp any perhaps occurring impacts. 
         [0123]    In the installed state no play is given between the axial contact area  45  and the exterior partial planetary carrier  6 , while play is still given between the first hardened section  46  of the bulging  43  and a flange section of the sun gear  18  extending in the axial direction, similarly as between the first hardened section  47  and a section of the sun gear  18  extending in the radial direction. The bulging  43  may follow the exterior contour of the sun gear  18  also in a 90°-angled section and show a distance as low as possible. 
         [0124]    The variant of the bearing sheath  40  of  FIGS. 18 to 22  shows a shorter axial length than the exemplary embodiment according to  FIG. 16 . The shortest diameter of the bearing sheath  40  ranges from 43 to 45 mm, preferably amounts to 44 mm. The exterior diameter in the area of the axially aligned contact area  45  amounts to approximately 10% more, preferably 47.9 mm. The entire exterior diameter at the largest place shows a value of 68 mm. It is also advantageous if the exterior diameter at the largest point is greater by one third than the interior diameter at the smallest point of the bearing sheath  40 . Further it is advantageous when the axial length amounts to more than one fourth of the interior diameter but less than half the interior diameter, preferably showing 16 mm. The bearing sheath of  FIG. 21  is also provided with a homogenously thick wall. 
         [0125]    In  FIG. 22  the bearing sheath  40  of  FIG. 21  is installed in the transmission combination  1 . 
         [0126]    The gliding ring  41  shown singularly in  FIGS. 24 and 27  is installed in the exemplary embodiments of  FIGS. 23 ,  25 , and  26 . 
         [0127]    The arrangement of the gliding ring  41  radially inside the bearing sheath  40 , namely axially between the bulging  43  and the axially aligned contact section  45 , is particularly clearly discernible from  FIGS. 23 ,  25 , and  26 . 
         [0128]    Gliding ring  41  shows recesses  50  such that elastic bars  51  form, which can also be called spring bars. Recesses  50  can be embodied like labyrinths. In an exemplary embodiment, elastic bars  51  are Z-shaped. One recess  50  each is aligned from one axial side to the other axial side, with one recess each beginning at one side and the other recess  50  beginning at the other side so that a “Z” is embodied with a right angle. Gliding ring  41  is produced from plastic. Z-shaped bars  51  are evenly distributed over the circumference. In general, it is also possible that bearing sheath  40  is made from materials other than spring steel, particularly other types of sheet metal. Plastic gliding ring  41  can latch in the extension given between contact area  45  and securing section  49 . This radially inwardly off-set securing section  49  can also be called a bulging. 
         [0129]    The five bars  51  allow a change of the diameter of gliding ring  41 . Thickness  52  of gliding ring  41  is greater than the width of recess  50  measured in the circumferential direction, as also discernible from  FIG. 27 . 
       LIST OF REFERENCE NUMBERS 
       [0000]    
       
           1  Transmission combination 
           2  Differential gear 
           3  Planetary stage 
           4  Spur differential 
           5  Planetary carrier 
           6  Exterior partial planetary carrier of the differential gear 
           7  Exterior partial planetary carrier of the planetary stage 
           8  Central partial planetary carrier 
           9  Exterior side 
           10  Gearing 
           11  Rivet 
           12  Recess 
           13  Planetary Gear pair 
           14  First planetary gear 
           15  Second planetary gear 
           16  Planetary gear of the planetary stage 
           17  Sun gear 
           18  Sun gear 
           19  Bolt 
           20  Connecting bolt 
           21  Sheath 
           22  Radially projecting flange 
           23  Disk between the central partial planetary carrier and the first sun gear 
           24  Friction disk/friction ring 
           25  Disk between the planetary gear of the planetary stage and the central partial planetary carrier 
           26  Bar 
           27  Axial end 
           28  Radial interior 
           29  Radial exterior 
           30  Hole in the exterior partial planetary carrier 
           31  Side 
           32  Material recess 
           33  Hole for connecting bolt 
           34  Hole for support bolt 
           35  Support bolt 
           36  Bead 
           37  Surface area 
           38  Surface 
           39  Cavity 
           40  Bearing sheath 
           41  Gliding ring 
           42  Ring 
           43  Bulging 
           44  Radially projecting support area 
           45  Axially aligned contact area 
           46  First hardened area (axially aligned) 
           47  Second hardened area (radially aligned) 
           48  Third hardened area (axially aligned) 
           49  Radially inwardly off-set securing area 
           50  Recess 
           51  Elastic bar 
           52  Thickness