Patent Publication Number: US-2022235826-A1

Title: Gear-tooth system and shaft/hub connection component

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage of, and claims priority to, Patent Cooperation Treaty Application No. PCT/EP2019/065631, filed on Jun. 14, 2019, which application is hereby incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     An arrangement having a profiled gear-tooth system between a shaft journal and a hub is known from DE 91 16 324. At least one of the profiled gear-tooth systems has a narrowed tooth width with an unchanged tooth height at its end that is at the front when the gear-tooth systems are joined together. 
     A shaft/hub connection arrangement having gear-tooth systems on shaft and hub, which engage into one another, is known from DE 10 2005 035 706 B4. The gear-tooth systems have a minimal tooth gap width in a first region and a maximal tooth gap width in a second region. During joining of the gear-tooth systems, the regions having the maximal tooth gap width come into engagement with one another at first, so that here, low pressure and/or a transition fit or a play fit between the gear-tooth systems is present. Toward the end of joining of the gear-tooth systems, a region having a minimal tooth gap width then comes into engagement with a region having a maximal tooth gap width, in each instance, so that here, stronger pressure and/or a press fit is present between the gear-tooth systems. 
     Such pairings of gear-tooth systems allow easier axial joining of the components by way of the gear-tooth system, since the flanks of the teeth of the gear-tooth systems, which flanks lie opposite one another, only come to bear after a certain press-in length, and with one another form the fit (for example a press fit) for the later purpose of use. 
     In this way, joining of gear-tooth systems can be simplified, since the risk of tilting can be reduced. It would be possible to place the components with a greater position tolerance relative to one another, wherein a more precise (self) orientation of the components relative to one another takes place only during the course of joining. 
     However, production of such gear-tooth systems is problematical, in particular if the gear-tooth systems are supposed to be produced in large numbers and during a short cycle time. Furthermore, it should be possible to produce the gear-tooth systems without burrs, if at all possible, i.e. so as not to require any rework (for example to remove burrs), if at all possible. Burrs on the gear-tooth systems are problematical, since they are displaced into the region of the subsequent bearing connection between the tooth flanks during joining, and in this regard hinder joining, for one thing, and for another thing can influence the bearing behavior of the gear-tooth systems that are in engagement with one another. In particular, burrs lead to scraping off of material during joining of non-hardened hubs, which material can then greatly increase the axial joining force. In this regard, the maximally permissible joining force is often exceeded. The scraped-off material can furthermore be pressed into a groove provided in the gear-tooth system, and there hinder the function of a locking ring to be disposed in the groove. 
     A method for producing a stepped gear-tooth system is known from DE 11 2005 003 630 B4. In this regard, a component of a shaft/hub connection is permanently held in a chuck, and is given an at least two-stage gear-tooth system by means of a tool. 
     SUMMARY 
     The present disclosure includes a method for producing a gear-tooth system, for example on a hub (inner gear-tooth system) or on a shaft (outer gear-tooth system). The disclosure furthermore includes a component of a shaft/hub connection, which component has a gear-tooth system. 
     A method includes producing a gear-tooth system (in particular a wedge gear-tooth system) on a component of a shaft/hub connection. The component is a shaft and/or a hub, therefore the gear-tooth system is an outer gear-tooth system disposed on an outer circumference surface or an inner gear-tooth system disposed on an inner circumference surface. The components of the shaft/hub connection are connected with one another by way of the gear-tooth system, so that a shape-fit connection between the components is implemented by way of the gear-tooth system, at least relative to a circumferential direction. 
     The component has a first axis of rotation and a gear-tooth system. The gear-tooth system of the component comprises a plurality of teeth (having the same configuration), which are disposed next to one another along a circumferential direction (at equal intervals), wherein a tooth interstice is disposed between two teeth, in each instance, and each tooth has a head region and a flank region, in each instance, disposed between the head region and a foot region disposed in the tooth interstice. The tooth interstice has a tooth gap width in the flank region. The gear-tooth system has at least a first region and subsequently a second region along an axial direction parallel to the first axis of rotation. The first region has a first tooth gap width and the second region has a second tooth gap width, which is less in comparison. The method (for producing this gear-tooth system) comprises at least the following steps:
     a) making the component available in a first initial state, wherein the component has the gear-tooth system, wherein the gear-tooth system has the second tooth gap width in the first region and in the second region;   b) machining at least the first region and enlarging the second tooth gap width to form the first tooth gap width.   

     The gear-tooth system is a straight gear-tooth system, in which the teeth extend exclusively along the axial direction. The gear-tooth system can also be a slanted gear-tooth system, in which the teeth additionally extend along the circumference direction. The form of the gear-tooth system is not limited. 
     The gear-tooth system is an involute gear-tooth system. 
     The component forms a gear wheel having an outer gear-tooth system and/or an inner gear-tooth system. The gear-tooth system has a uniform division (in other words an arrangement of equal teeth along the circumference direction, with equal intervals). The gear wheel therefore has a modulus (diameter division; generally used dimension for describing gear-tooth systems). 
     The tooth gap width changes along a radial direction between head region and foot region of the teeth. Here, the (first and second) tooth gap width is determined, in each instance, at an equal distance from the first axis of rotation. The tooth gap width is determined in the flank region of the teeth. A partial circle (or rolling circle) extends through the flank region. In particular, the tooth gap width is determined on the partial circle. 
     Here, the flank region refers to the region of a gear-tooth system of a shaft/hub connection intended for contacting the teeth of shaft and hub. 
     Here it is possible to structure the gear-tooth system uniformly at first (at least with regard to the tooth gap width), and to make it available with the same tooth gap width (with the lower second tooth gap width) according to Step a). 
     In particular, here the gear-tooth system can already be structured with steps, for example (in other words foot regions or head regions of the gear-tooth system that are structured differently). 
     In particular, the gear-tooth system can have a slanted position of the teeth (in other words a progression at an angle relative to an axial direction); in other words it can form a helix gear-tooth system, for example. 
     According to Step b), the first region is machined and the tooth gap width is enlarged. 
     Machining takes place by means of displacement and/or by means of removal of material of the component. 
     A different tool is used for producing the first tooth gap width than for producing the gear-tooth system or for producing the second tooth gap width. 
     Step b) can take place in a separate production step, for example on a different machine and/or in a different clamping process and/or with a time offset relative to production of the gear-tooth system having the second tooth gap width. 
     Step b) can take place after introduction of one or more grooves, in terms of time. 
     Step b) can be carried out using a rolling tool. Using a rolling tool, it is possible to achieve (local) displacement and/or compaction of the material of the component by means of a roll-off movement between tool and component. 
     Alternatively, Step b) can be carried out using a drawing tool, in other words formation of the gear-tooth system can be carried out within the scope of impact extrusion (during which the component is pressed into or through a die that forms the gear-tooth system—or vice versa). 
     A drawing tool is fundamentally known, wherein a drawing die is explained in greater detail in DE 11 2005 003 630 B4, for example. 
     In particular, the rolling tool is
         a rolling rod that is moved at least transverse to the first axis of rotation relative to the component, so as to produce the gear-tooth system; or   a roller burnishing tool having at least one rolling wheel, wherein the rolling wheel has a second axis of rotation that runs parallel to the first axis of rotation.       

     The rolling rod and the rolling wheel are fundamentally known and are explained in greater detail in DE 11 2005 003 630 B4, for example. 
     Targeted displacement of material out of the flank region can take place by means of rolling. In particular, the material displacement can take place at least in the radial direction, in other words toward a foot region and/or toward a head region of the teeth. In these regions, in general no contacting with the other component of the shaft/hub connection is provided for during planned use of the component. In this way, additional material can be placed here, without disadvantages having to be feared during subsequent use of the component. 
     The rolling tool can be a roller burnishing tool, wherein the at least one rolling wheel for producing the engagement into the gear-tooth system is moved at least (preferably exclusively) transverse to the axial direction, at an infeed speed. Immediately before contact between rolling wheel and component, at least the component rotates about the first axis of rotation or the one rolling wheel rotates about the second axis of rotation. 
     In particular, a rolling wheel can machine all gear-tooth systems that have the same modulus, independent of the number of teeth of the component to be machined. 
     Only one of (at least one) rolling wheel and component is driven, so that a rotational movement of the one part (rolling wheel or component) is transferred to the other part (component or rolling wheel). 
     The roller burnishing tool is moved toward the component at an infeed speed, wherein within the scope of this infeed movement, the contact, the engagement into the gear-tooth system (in other words the interaction between the gear-tooth system on the rolling wheel and on the component) and, if applicable, also the transfer of the rotational movement from the one part to the other part takes place. 
     The infeed speed (at least immediately before and during contact and engagement) can is at least 0.2 millimeters/second, preferably at least 1.0 millimeters/second, particularly preferably at least 8.0 millimeters/second. For example, the infeed speed can is between 0.2 millimeters/second and 10 millimeters/second, particularly at most 6 millimeters/second. 
     A rotational speed of the component (and thereby of the at least one rolling wheel) during Step b) can is at least 100 revolutions/minute, preferably at least 200 revolutions/minute, particularly preferably at least 400 revolutions/minute. For example, the rotational speed can is between 100 revolutions/minute and 1,000 revolutions/minute, preferably between 100 and 600 revolutions/minute. 
     With the proposed rolling methods for carrying out Step b), it is possible to implement a very short cycle time for Step b), so that a great number of components can be produced within a short time. In this regard, high quality of the gear-tooth system can be implemented, wherein burrs are removed by means of the rolling method or do not occur in the first place. 
     In particular, a groove that runs in the circumference direction can be introduced into the gear-tooth system between Step a) and b), within the first region. This groove is necessary for the subsequent purpose of use of the component. 
     Introduction of the groove, which in particular reaches into the component more deeply than the foot region of the gear-tooth system, usually takes place by means of a material-removing method, for example lathing. In particular, in this regard burrs are formed at the edges between groove and gear-tooth system. These burrs are reshaped or broken by means of the machining according to Step b), in such a manner that they no longer reach into the tooth gaps and no longer have a negative influence on joining with a hub, for example. An additional machining step for removing the burrs is therefore not required. 
     In particular, during Step b), a material of the component is displaced out of the flank region, at least (for the most part or exclusively within the first region) in a radial direction, at least in the first region, at least toward the head region or toward the foot region. Displacement of material in the axial direction can occur in the edge region of the first region (in other words at the transition to the second region, for example). An accumulation of material, which occurs, for example, when using a drawing tool, and reduces the tooth gap width of the teeth already present, does not occur here. 
     In particular, a transition region can be provided between the first region and the second region, in which the first tooth gap width continuously decreases along the axial direction, toward the second tooth gap width. To implement this transition region, the rolling tool can have a corresponding shape, for example, so that increasingly lesser engagement between rolling tool and gear-tooth system of the component takes place toward the edge of the rolling tool. 
     The first tooth gap width produced according to Step b) (as an average over multiple measurement points) cam be at least 1 micrometers, preferably at least 10 micrometers, particularly preferably at least 100 micrometers greater than the second tooth gap width, measured at the same position (same diameter; if possible same tooth). 
     Furthermore, a component of a shaft/hub connection is disclosed. The component has a first axis of rotation and a gear-tooth system. The gear-tooth system comprises a plurality of teeth, which are disposed next to one another along a circumference direction, wherein a tooth interstice is disposed between two teeth, in each instance, and each tooth has a head region and a flank region, in each instance, disposed between the head region and a foot region disposed in the tooth interstice. The tooth interstice has a tooth gap width in the flank region. The gear-tooth system has at least a first region and subsequently a second region along an axial direction parallel to the first axis of rotation; wherein the first region has a first tooth gap width and the second region has a lesser second tooth gap width in comparison with the first. 
     The component is produced at least by means of the method described. Alternatively or in addition, the first tooth gap width decreases continuously, proceeding from a first region end of the first region and toward the second region, at least in a partial region. 
     In particular, in the entire first region, the first tooth gap width is greater than the second tooth gap width in the second region. 
     The gear-tooth system extends, at least proceeding from a first region end of the first region, along the axial direction, over the first region (and, if applicable, the groove), if applicable over a transition region, and over the second region. 
     The partial region can form the first region end, and at least a remaining region having a constant first tooth gap width can be disposed between the partial region and the second region. The remaining region is part of the first region. The remaining region is disposed (at least) between the partial region and the groove. If applicable, the remaining region extends beyond the groove. 
     The teeth are structured conically, at least in the partial region, i.e. they widen continuously toward the second region. 
     A transition region can be formed between the first region and the second region as well as the partial region, wherein, however, the first tooth gap width decreases to the second tooth gap width in the transition region. 
     Furthermore, a shaft/hub connection is disclosed, at least comprising a shaft and a hub, which have a gear-tooth system, in each instance, by way of which they are connected with one another (with shape fit relative to the circumference direction). At least one of the parts, shaft and hub, is the component described. For forming the shaft/hub connection, the shaft and the hub can be displaced relative to one another by way of a first component end (of the component shaft and of the component hub; for example an end face), along an axial direction, toward one another. The first region of the respective component (which is structured like the component described, in other words one of shaft and hub or both) is disposed between the first component end of the component and the second region of the component. 
     If shaft and hub are arranged one on top of the other, in other words displaced toward one another, first the first region of the gear-tooth system of the component described will come into engagement with the gear-tooth system of the other component, shaft and hub. The first region has the enlarged tooth gap width, so that assembly of the shaft/hub connection is simplified. 
     The gear-tooth systems (of shaft and hub) at first can form a greater fit during formation of the shaft/hub connection (for example a play fit) with one another (if, for example, only the first region is in engagement with the respective other gear-tooth system). During further displacement of shaft and hub relative to one another and when a predetermined end position is reached, the gear-tooth systems form a tighter fit (for example a press fit) with one another, at least in the second region of the gear-tooth system of the component. 
     The explanations regarding the method can be transferred to the component and the shaft/hub connection, and vice versa, in each instance. 
     As a precaution, it should be noted that the counting words used here (“first,” “second,” . . . ) serve primarily (only) for differentiating between multiple objects, variables or processes of the same type, in other words do not compulsorily indicate any dependence and/or sequence of these objects, variables or processes relative to one another. If any dependence and/or sequence is/are required, this is explicitly stated here or it is obvious to a person skilled in the art when studying the embodiment concretely described. If a component can occur multiple times (“at least one”), the description regarding one of these components can apply equally for all or part of the plurality of these components, but this is not compulsory. 
    
    
     
       BRIEF SUMMARY OF THE DRAWINGS 
       The disclosure will be explained in greater detail below, using the attached figures. It should be pointed out that the invention is not supposed to be restricted by the exemplary embodiments mentioned. In particular, it is also possible, unless explicitly stated otherwise, to extract partial aspects of the facts explained in the figures and to combine them with other integral parts and knowledge from the present description. In particular, it should be pointed out that the figures and the size ratios shown are only schematic. The figures show: 
         FIG. 1 : a shaft and a hub for producing a shaft/hub connection, in a side view, partly in section; 
         FIG. 2 : a detail of the shaft according to  FIG. 1  in a side view, in section; 
         FIG. 3 : an apparatus for producing the gear-tooth system on a shaft, in a side view; 
         FIG. 4 : a shaft having a gear-tooth system, in a view along the axial direction; 
         FIG. 5 : a change in the gear-tooth system by means of Step b) of the method, shown using a cross-section; in a view along the axial direction; 
         FIG. 6 : a detail of a gear-tooth system of a shaft/hub connection, in a perspective view; 
         FIG. 7 : multiple embodiment types of a gear-tooth system geometry, shown using different teeth of a shaft; in a perspective view; 
         FIG. 8 : a roller burnishing tool for machining the gear-tooth system according to Step b), in engagement with a component, in a side view, in section; 
         FIG. 9 : a progression of machining the gear-tooth system according to  FIG. 8 , in a side view, in section; 
         FIG. 10 : a rolling wheel of the roller burnishing tool according to  FIGS. 8 and 9  in a view along a second axis of rotation; and 
         FIG. 11 : the rolling wheel according to  FIG. 10  in a side view, in section. 
     
    
    
     DESCRIPTION 
       FIG. 1  shows a shaft  28  and a hub  29  for producing a shaft/hub connection  3 , in a side view, partly in section. 
     Shaft  28  and hub  29  each have a gear-tooth system  1 , by way of which they are connected with one another (relative to the circumference direction  6 , with shape fit). At least one of shaft  28  and hub  29  (here at least the shaft  28 ) is the component  2  described. To form the shaft/hub connection  3 , the shaft  28  and the hub  29  (of the component shaft  28  and of the component hub  29 ; here, an end face, in each instance) can be displaced relative to and toward one another, along an axial direction  13 , by way of a first component end  30 . The first region  14  of the gear-tooth system  1  of the shaft  28  is disposed between the first component end  30  of the component  2  and the second region  15  of the component  2  (the shaft  28 ). 
     If shaft  28  and hub  29  are disposed one on top of the other, in other words displaced toward one another, first the first region  14  of the gear-tooth system  1  of the component  2  (here the shaft  28 ) will come into engagement with the gear-tooth system  1  of the other component (here the hub  29 ). The first region  14  has the enlarged tooth gap width, so that assembly of the shaft/hub connection  3  is simplified. 
     In this regard, the gear-tooth systems  1  (of shaft  28  and hub  29 ) first form a greater fit (for example a play fit) with one another when forming the shaft/hub connection  3  (if only the first region  14  is in engagement with the respectively other gear-tooth system  1 ). During further displacement of shaft  28  and hub  29  relative to one another and when a predetermined end position  31  is reached, the gear-tooth systems  1  form a tighter fit (for example a press fit) with one another, at least in the second region  15  of the gear-tooth system  1  of the component  2 . 
       FIG. 2  shows a detail of the shaft  28  according to  FIG. 1  in a side view, in section.  FIG. 3  shows an apparatus for producing the gear-tooth system  1  on a shaft  28 , in a side view.  FIG. 4  shows a shaft  28  having a gear-tooth system  1 , in a view along the axial direction  13 .  FIG. 5  shows a change in the gear-tooth system  1  by means of Step b) of the method, represented using a cross-section; in a view along the axial direction  13 .  FIG. 6  shows a detail of a gear-tooth system  1  of a shaft/hub connection  3 , in a perspective view.  FIG. 7  shows multiple embodiment types of a gear-tooth system geometry, represented for different teeth  5  of a shaft  28 ; in a perspective view.  FIGS. 2 to 7  will be described together hereinafter. 
     The gear-tooth system  1  is a straight gear-tooth system, in which the teeth  5  extend exclusively along the axial direction  13 . 
     The component  2  forms a gear wheel having an outer gear-tooth system. The gear-tooth system  1  has a uniform division. The gear-tooth system  1  of the component  2  comprises a plurality of (equally configured) teeth  5 , which are disposed next to one another along a circumference direction  6 , wherein a tooth interstice  7  is disposed between two teeth  5 , in each instance, and each tooth  5  has a head region  8  and a flank region  10 , disposed between head region  8  and a foot region  9  disposed in the tooth interstice  7 , in each instance. The tooth interstice  7  has a tooth gap width  11 ,  12  in the flank region  10 . The gear-tooth system  1  has at least a first region  14  and subsequently a second region  15  along an axial direction  13  that lies parallel to the first axis of rotation  4 . 
     The first region  14  has a first tooth gap width  11 , and the second region  15  has a second tooth gap width  12 , which is less, in comparison. The tooth gap width  11 ,  12  changes along a radial direction  24 , between head region  8  and foot region  9  of the teeth  5  (see  FIG. 4 ). Here, the (first and second) tooth gap width  11 ,  12  is determined at the same distance from the first axis of rotation  4 , in each instance. The tooth gap width  11 ,  12  is determined in the flank region  10  of the teeth  5 . A partial circle  32  (or rolling circle) extends through the flank region  10 . 
     The gear-tooth system  1  according to  FIGS. 2 and 7  is structured with steps (in other words differently structured foot regions  9  of the gear-tooth system  1 ). 
     According to the method for producing the gear-tooth system  1 , according to Step a), the component  2  is made available in an initial state, wherein the component  2  has the gear-tooth system  1 , and the gear-tooth system  1  has the (narrower) second tooth gap width  12  in the first region  14  and in the second region  15 . According to Step b), machining of the first region  14  and enlargement of the second tooth gap width  12  to form the first tooth gap width  11  takes place (see  FIGS. 2, 5, and 7 ). 
     Within the first region  14 , a groove  22  that runs along the circumference direction  6  is introduced into the gear-tooth system  1 . The groove  22  reaches deeper into the component  2  than the foot region  9  of the gear-tooth system  1 . 
     During Step b), a material  23  of the component  2  is displaced, at least in the first region  14 , out of the flank region  10 , in a radial direction  24 , at least toward the head region  8  or toward the foot region  9 . In  FIG. 5 , it is shown that the gear-tooth system  1  has a second tooth gap width  12  before Step b) (first contour  33  of the gear-tooth system  1 ). After Step b), the gear-tooth system has a first tooth gap width  11  (second contour  34 ). It is evident that material  23  of the component  2  was displaced out of the flank region  10  into the head region  8  and into the foot region  9 . 
     A transition region  35  is provided between the first region  14  and the second region  15 , in which the first tooth gap width  11  is continuously reduced, along the axial direction  13 , toward the second tooth gap width  12 . To implement this transition region  35 , the rolling tool can have a corresponding shape, for example, so that an increasingly lesser engagement between rolling tool and gear-tooth system  1  of the component  2  takes place toward the edge of the rolling tool (see  FIG. 11 , shown there using a rolling wheel  18 ). 
     In  FIG. 3 , it is shown that the shaft  28  is disposed in a clamping arrangement on both sides, and is machined, at both component ends  30 , using a rolling tool to produce the gear-tooth system  1 . 
     Here, only the second tooth gap width  12  is produced by way of the rolling tool (in other words the state of the shaft  28  before Step b) of the method). Machining according to Step b) can take place in a similar clamping arrangement, with different rolling wheels  18 . 
     A rolling wheel  18  having a second axis of rotation  19  (left rolling tool) can be used as a rolling tool (see also  FIGS. 8 to 11 ) or a rolling rod  16  (right rolling tool) can be used, which is moved transverse to the first axis of rotation  4  relative to the component  2 . A function of the rolling rod is explained in DE 11 2005 003 630 B4, for example. 
     In  FIG. 6 , it is shown that if shaft  28  and hub  29  are disposed one on top of the other, in other words displaced toward one another, first the first region  14  of the gear-tooth system  1  of the component  2  comes into engagement with the gear-tooth system  1  of the other component of shaft  28  and hub  29 . The first region  14  has the enlarged first tooth gap width  12 , so assembly of the shaft/hub connection  3  is simplified by means of the greater play  36  in the flank region  10 . 
     In  FIG. 7 , multiple types of a gear-tooth system geometry are shown. The teeth  5  extend along the axial direction  13 , proceeding from the first component end  30 . In the foot region  9  of the gear-tooth system  1 , steps are arranged in the second region. 
     The tooth  5  shown on the left extends along the axial direction  13  with a flank region  10  that runs parallel to the axial direction  13 . In interplay with similar teeth  5 , a constant first tooth gap width  11  is formed in this way, along the axial direction  13 , in the first region  14 . 
     In the case of the center tooth  5 , the flank regions  10  run at an angle relative to the axial direction  13 , so that in interplay with similar teeth  5 , a first tooth gap width  11  that is continuously reduced is implemented. The first tooth gap width  11  is continuously reduced, proceeding from a first region end  25  of the first region  14  (here at the first component end  30 ) and toward the second region  15 , over the entire first region  14 . 
     The center tooth  5  is structured conically, at least in the first region  14 , i.e. it widens continuously toward the second region  15 . 
     In the case of the right tooth  5 , only a partial region  26  of the first region  14  is structured conically, so that the tooth  5  widens continuously toward the second region  15  only in the partial region  26 . 
     The partial region  26  is disposed directly at the first region end  25 , wherein a remaining region  27  having a constant first tooth gap width  11  (in other words with flank regions  10  of the teeth  5  that run parallel to the axial direction  13 ) is disposed between the partial region  26  and the second region  15 . The remaining region  27  is part of the first region  14 . The remaining region  27  is disposed between the partial region  26  and the groove  22 . 
     In the case of all the teeth  5  of the different gear-tooth systems shown, the transition region  35  is disposed directly following the groove  22  and toward the second region  15 . 
     The transition region  35  of each tooth  5  is disposed between the first region  14  and the second region  15  and structured like the partial region  26  of the right two teeth  5 , wherein in the transition region  35 , the first tooth gap width  11  is reduced to the second tooth gap width  12 . 
     For all the gear-tooth systems  1  shown, it holds true that in the entire first region  14 , the first tooth gap width  11  is greater than the second tooth gap width  12  in the second region  15 . 
     The gear-tooth system  1  extends, proceeding from a first region end  25  (disposed at the first component end  30 ) of the first region  14 , along the axial direction  13 , over the first region  14  (and the groove  22 ), over a transition region  35 , and over the second region  15 . 
       FIG. 8  shows a roller burnishing tool  17  for machining the gear-tooth system  1  according to Step b), in engagement with a component  2 , in a side view, in section.  FIG. 9  shows a progression of machining of the gear-tooth system  1  according to  FIG. 8 , in a side view, in section.  FIGS. 8 and 9  will be described together hereinafter. Reference is made to the explanations regarding  FIGS. 1 to 7 . 
     The rolling tool is a roller burnishing tool  17 , wherein the two rolling wheels  18  for producing the engagement into the gear-tooth system  1  on component  2  are moved at least transverse to the axial direction  13 , at an infeed speed  19 . Immediately before contact of rolling wheels  18  and component  2 , at least the component  2  rotates about the first axis of rotation  4 . 
     Here, only the component  2  is driven, so that a rotational movement of the component  2  is transferred to the rolling wheels  18 . 
     The roller burnishing tool  17  is moved toward the component  2  at an infeed speed  19 , wherein within the scope of this infeed movement, the contact, the engagement into the gear-tooth system  1  (in other words the interaction between gear-tooth system  1  on the rolling wheel  18  and on the component  2 ) and, if applicable, also the transfer of the rotational movement from the one part to the other part takes place. 
     In  FIG. 9 , the broken-line representation of the rolling wheel  18  represents the position of the rolling wheel  18  at the moment of production of the first contact between the gear-tooth system  1  of the rolling wheel  18  and the gear-tooth system  1  of the component  2 . The representation of the rolling wheel with a solid line represents the position of the rolling wheel  18  when machining of the gear-tooth system  1  in the first region  14  according to Step b) of the method has just taken place. During the advancing movement of the rolling wheels  18  along a direction transverse to the axial direction  13  or transverse to the first axis of rotation  4 , the rolling wheels  18  are disposed at a constant distance from one another. 
       FIG. 10  shows a rolling wheel  18  of the roller burnishing tool  17  according to  FIGS. 8 and 9  in a view along a second axis of rotation  19  of the rolling wheel  18 .  FIG. 11  shows the rolling wheel  18  according to  FIG. 10  in a side view, in section.  FIGS. 10 and 11  will be described together hereinafter. Reference is made to the explanations regarding  FIGS. 1 to 9 . 
     The rolling wheel  18  has a gear-tooth system  1  for forming the first tooth gap width  11 . 
     A transition region  35  can be provided between the first region  14  and the second region  15 , in which the first tooth gap width  11  is continuously reduced in size along the axial direction  13 , toward the second tooth gap width  12 . To implement this transition region  35 , the rolling tool (here the rolling wheel  18 ) can have a corresponding shape, so that increasingly lesser engagement between rolling tool and gear-tooth system  1  of the component  2  occurs toward the edge of the rolling tool. Here, the rolling wheel  18  has a transition region  35  described in connection with  FIG. 7 . 
     REFERENCE SYMBOL LIST 
     
         
         
           
               1  gear-tooth system 
               2  component 
               3  shaft/hub connection 
               4  first axis of rotation 
               5  tooth 
               6  circumference direction 
               7  tooth interstice 
               8  head region 
               9  foot region 
               10  flank region 
               11  first tooth gap width 
               12  second tooth gap width 
               13  axial direction 
               14  first region 
               15  second region 
               16  rolling rod 
               17  roller burnishing tool 
               18  rolling wheel 
               19  second axis of rotation 
               20  infeed speed 
               21  rotational speed 
               22  groove 
               23  material 
               24  radial direction 
               25  first region end 
               26  partial region 
               27  remaining region 
               28  shaft 
               29  hub 
               30  first component end 
               31  end position 
               32  partial circle 
               33  first progression 
               34  second progression 
               35  transition region 
               36  play 
               37  step