Title of Invention

"SHAFT/HUB CONNECTION WITH SECURING SYSTEM"

Abstract

The invention relates to an arrangement having a shaft with an external splining of a limited length that is embodied at a shaft end; having a hub with an internal splining that extends essentially the length of the hub - the external splining and the internal splining engaging each other to permit a transmission of torque between the shaft and hub; having a first axial securing means that functions between the shaft and hub, prevents the hub from sliding further onto the shaft, and is comprised of a stop surface on the hub and a counterpart surface on the shaft or a part connected to it at the end of the hub oriented toward the main body of the shaft; and having a second axial securing means that functions between the shaft and hub, prevents the hub from being pulled off from the shaft, and includes a securing ring that is situated at the end of the shaft and the end of the hub oriented toward the shaft end and that engages in radial recesses in the shaft and hub, which recesses constitute the contact surfaces for this securing ring on the shaft and hub. The invention also relates to a method for manufacturing a shaft for such a connection.

Full Text

[Translation from German] Shaft/Hub Connection With Securing System The invention relates to an arrangement having a shaft with an external splining of a limited length that is embodied at a shaft end; having a hub with an internal splining that extends essentially the length of the hub - the external spiining and the internal splining engaging each other to permit a transmission of torque between the shaft and hub; having a first axial securing means that functions between the shaft and hub, prevents the hub from sliding further onto the shaft, and is comprised of a stop surface on the hub and a counterpart surface on the shaft or a part connected to it at the end of the hub oriented toward the main body of the shaft; and having a second axial securing means that functions between the shaft and hub, prevents the hub from being pulled off from the shaft, and includes a securing ring that is situated at the end of the shaft and the end of the hub oriented toward the shaft end and that engages in radial recesses in the shaft and hub, which recesses constitute the contact surfaces for this securing ring on the shaft and hub. The invention also relates to a method for manufacturing a shaft for such a connection. Known securing systems between a shaft and a hub with a ball track of a constant velocity joint are embodied such that a securing ring guided in a groove is provided between the shaft and hub and prevents the hub from coming off from the shaft in the axial direction. In this connection, there have up to now been two different structural embodiments of the groove in the hub. The first embodiment is provided for a detachable shaft/hub connection and the second embodiment is provided for a non-detachable shaft/hub connection. In this context, there is only one structural embodiment for a shaft with external splining, with one structural embodiment of an annular groove; the annular groove has two steep flanks of less than 0°. In the detachable embodiment of the shaft/hub connection, the securing ring prevents the hub on the shaft from coming off in the axial direction during operation of the constant velocity joint, whereas for repair or maintenance purposes, the structural embodiment is selected so that the hub can essentially be detached from the shaft. In the detachable variant, the securing groove in the hub has a flank closer to the shaft end with an angle of greater than or equal to (>) 15°. The securing groove of the hub exerts the compressive forces on the securing ring so that the securing ring is compressed and the hub can be detached. In the non-detachable embodiment of the shaft/hub connection, the securing ring prevents the hub on the shaft from coming off in the axial direction during operation of the constant velocity joint; the structural design is selected so that the hub essentially cannot be detached from the shaft. In the non-detachable variant, the securing groove in the hub has a flank closer to the shaft end with an angle of less than or equal to ( groove in the hub does not exert any compressive forces on the securing ring so that the securing ring is not compressed and the hub cannot be detached. Consequently, according to the prior art, two different structural embodiments of the hub must be produced in order to achieve a detachable variant and a non-detachable variant. This sharply increases production costs because it requires two different variants to be manufactured and stored. The primary disadvantage lies in the fact that in production and assembly, it is very difficult to differentiate between the two hub variants if they have not been labeled beforehand as to whether they are "detachable" or "non-detachable". It is almost impossible to visually differentiate between the detachable variant and the non-detachable variant because of the extremely small difference in the flank angle of the securing groove. Additionally providing an "identification groove" or another marking that is visible even after assembly incurs additional costs. An arrangement with axial securing means is known from DE 4,229,726 A1. In this case, the first axial securing means is comprised of the external splining end oriented toward the main body of the shaft, the end surface of the hub or the internal splining, and a plastic insert ring whose shape is altered by these splinings. The second axial securing means is comprised of a simple rectangular-section ring that rests against the end of the hub oriented toward the shaft end and lies in a simple rectangular-section groove in the shaft at the protruding shaft end. This second axial securing means can only be used if its spatial placement is freely accessible for assembly and disassembly purposes. This is not the case, for example, if it is necessary to join a shaft to a ball hub of a preassembled swivel joint that is closed on one side. This requires a self-locking securing ring that is preinstalled into the annular groove in the shaft. JP 5-22089 B2 has disclosed an arrangement including a hub body and a shaft in which the hub body is embodied in the form of a bevel gear of a differential. In this case, the first axial securing means between the hub body and the shaft is completely eliminated since the hub body is supported axially against a housing in which the shaft is supported. The external splining provided here extends all the way to the end of the shaft. Spaced a bit apart from the shaft end, an annular groove with an inclined flank is cut into the splined region. This makes it possible for the shaft, which has a securing ring inserted into the annular groove, to be inserted into the hub body. This elastically forces the securing ring with a round cross section into the annular groove and after the hub is slid on, the securing ring rests against an inclined flank of the hub in an elastically expanding manner so that the annular groove does not have to be accessible after the hub is slid into place. Since the annular groove is cut into the region of the hardened external splining, though, when the internal splining of the hub is slid into place, particularly in the case of a press-fitting, shavings can be pulled against the spline edges, which give rise to unpredictable assembly forces. GB 1,511,290 has disclosed a connection between an internally splined sleeve and an annular disk element, the latter serving to axially clamp spring-elastic ring elements whose external splining engages with the internal splining of the sleeve. The disk body here also has external splining that engages in the internal splining of the sleeve and is axially secured by a securing ring that is held in recesses in the sleeve and disk element. The disk element has a journal projection that has a smaller outer diameter than the tip diameter of the internal splining of the sleeve and the root circle diameter of the short external splining of the disk element. A transmission of torque between the sleeve and the disk element does not occur. GB 855,282 has disclosed an arrangement of a hub and a shaft in which a securing ring with a round cross section engages in recesses in the hub and shaft, which are embodied close to the end of the hub oriented toward the main body of the shaft. In this case, an annular groove is cut into the full-depth external splining on the shaft while an annular groove is cut into the internal splining inside the hub, but the tooth height of this internal splining decreases significantly from the annular groove to the end of the hub oriented toward the main body of the shaft. The means thus described perform the axial securing in both axial directions. DE 78 09 284 U1 has disclosed an arrangement comprising a hub and a shaft with an external splining and a hub with an internal splining in which at the end of the shaft, a transition cone is provided from the tip diameter of the external splining to a journal with a smaller diameter, the journal being embodied in the form of a screw journal. Inside the hub, spaced a bit apart from its end oriented toward the shaft end, the internal splining ends and an annular groove is cut into the hub; from the annular groove to the end of the hub oriented toward the shaft end, the inner diameter corresponds approximately to the root circle diameter of the internal splining. A nut is screwed onto the screw journal and rests against the nub. A securing ring with a circular cross section is situated between the transition cone on the shaft and a counterpart cone in the nut and lies in the annular groove in the hub. DE 4,040,337 A1 has disclosed an axial securing between a hub and a shaft, but does not provide any torque transmitting means, i.e. in particular does not provide any splining. A securing ring lies in recesses in the hub and in an annular groove close to the end of the shaft; the diameter of the shaft decreases between the annular groove in the shaft and the end of the shaft. The object of the present invention is to create an arrangement of the type described at the beginning in which the recesses in the hub and shaft are embodied in such a way that the recess in the shaft can accommodate an axial securing means that is easy and inexpensive to manufacture and assures a non-detachable connection between the shaft and hub while providing easy identification and not unnecessarily reducing the strength of the shaft. The solution for this lies in the fact that: the radial recess in the shaft constitutes a first stop surface for the securing ring, where the radial recess is embodied in the form of an annular groove with an annular groove diameter d1 and is adjoined in the direction toward the shaft end by an annular groove step with an annular groove step diameter d2 and where d2 is greater than d1; the end of the hub oriented toward the shaft end contains an expanding turned groove, which constitutes a second stop surface for the securing ring; and the securing ring is embodied in the form of a round snap ring. The placement of recesses in the shaft and hub in the immediate vicinity of the shaft end makes it possible to provide a shaft profile of unreduced strength in the entire splined region and in the entire region of the shaft. The embodiment of the annular groove and the annular groove step according to the invention assures that the hub cannot be nondestructively detached from the shaft since when axial tensile forces are exerted between the hub and shaft that would pull the hub off from the shaft, the contact surfaces on the hub do not push the snap ring back into the annular groove, but instead push it against the edge between the annular groove step and the flank toward the end of the shaft. An axial load exerted between the hub and shaft that would pull the hub off from the shaft can crush the securing ring so that it becomes completely wedged, thus possibly causing damage to the internal splining in the hub if a forced removal is attempted. In an advantageous embodiment of the invention, the annular groove step diameter d2 is smaller than the root diameter of the external splining on the shaft. In a likewise advantageous embodiment of the invention, the gap width of the annular groove is greater than or equal to (£) the diameter of the ring cross section of the securing ring and the gap width of the annular groove step is less than or equal to ( In an additional advantageous embodiment of the invention, the gap width of the annular groove is greater than the gap width of the annular groove step. In an additional advantageous embodiment of the invention, the gap width of the annular groove is approximately twice as great as the gap width of the annular groove step. In a likewise advantageous embodiment of the invention, the annular groove has a flank that is perpendicular to the shaft axis and closer to the main body of the shaft and has a perpendicular flank closer to the end of the shaft, and the annular groove step has a perpendicular flank closer to the end of the shaft. In a particularly advantageous embodiment of the invention, the diameter of the ring cross section of the securing ring is greater than the distance between the groove bottom of the annular groove step and the circumference surface of the recess. In addition, the first axial securing means includes a spline end of the external splining and a corresponding spline bevel at the end of the internal splining in the hub oriented toward the main body of the shaft. This represents a structurally favorable embodiment. However, other possible embodiments also include those according to the species-defining prior art. In a detachable connection of the hub and shaft, the hub has an inclined contact surface and only one annular groove is provided, which has two flanks perpendicular to the shaft axis so that when axial tensile forces are exerted between the hub and shaft that would pull the hub from the shaft, the contact surface on the hub pushes the snap ring back into the annular groove and the hub can be slid off over it. Preferred exemplary embodiments of the invention will be explained below in conjunction with four drawings. Fig. 1 shows an arrangement according to the invention of a shaft, securing ring, and hub in a non-detachable embodiment of the arrangement; Fig. 2 is an enlarged depiction of the arrangement according to the invention of a shaft, securing ring, and hub according to Fig. 1 in a non-detachable embodiment of the arrangement; Fig. 3 shows an arrangement according to the invention of a shaft, securing ring, and hub in a detachable embodiment of the arrangement; Fig. 4 is an enlarged depiction of the arrangement according to the invention of a shaft, securing ring, and hub according to Fig. 1 in a detachable embodiment of the arrangement; Fig. 1 is a depiction of a shaft 11, a hub 41, and a securing ring 51 showing the following details. On the shaft 11, from right to left in the broken view of the shaft body 21, an external splining 23, an annular groove 24, and an annular groove step 55 are visible. The shaft 11 with the external splining 23 ends with a bevel 26 at the end surface 27, which can also conceptually be referred to as the shaft end. The external splining 23 ends at a spline end 59 at which the splines come to an end. The annular groove 24 has a steep radial flank 30 on the side closer to the main body of the shaft, a cross-sectionally rounded groove bottom adapted to the securing ring, and a steep radial flank 31 whose height is less than that of the radial flank 30. The hub 41 has a ball track, not shown, which is of no further significance to the connection, and an internal splining 43 that engages the external splining 23 in a form-locked manner in the rotation direction. The drawing also shows that the hub has an end surface 44 oriented toward the main body of the shaft and an end surface 47 oriented toward the end of the shaft, which are conceptually equivalent to the respective ends. Starting from the end surface 44 oriented toward the main body of the shaft, the hub 41 contains an internal cone 45 whose opening angle can correspond to the inclination angle of the spline end 59 of the external splining 23. In addition, an internal cone is provided, which constitutes a bevel 46 that has a large inclination angle on the internal splining 43, cooperates with the spline end 28, and constitutes a first stop means that prevents the hub from sliding further onto the shaft when the structurally determined end position has been reached. Alternatively, this could also occur, for example, in the region of the internal cone 45, which would cooperate with the inclined end 59 to constitute a first stopping means. At the end surface 47 of the hub 41 oriented toward the end of the shaft, the hub has a recess 48 that on the one hand, constitutes a cylindrical circumference surface 49 and on the other hand, provides a conical stop surface 50 for the securing ring. The diameter of the recess can be less than the root diameter of the internal splining 43, thus permitting the surfaces 49 and 50 to be interrupted by the spline grooves of the internal splining 43. In Fig. 1, the internal splining 43 of the hub 41 has been slid axially all the way onto the external splining 23 of the shaft 11. The securing ring 51 contained in the annular groove 24 here presses radially outward under its own inherent stress. When the hub is being slid into place, the internal cone 45 and the internal splining 43 adjoining it press the securing ring 51 into the bottom of the groove. The internal cone surface 45 serves as an insertion bevel and the radial surface of the flank 30 serves as an opposing or guiding surface. The hub 41 is slid until the bevel 46 of the internal splining 43 comes into contact with the spline end 28 of the external splining 23. The securing ring 51 springs out from the groove bottom and rests with its outside against the inner cylindrical surface 49. The embodiment of the annular groove 24 and annular groove step 55 according to the invention assures that the hub 41 cannot be nondestructively detached from the shaft 11 since when axial tensile forces are exerted between the hub 41 and the shaft 11 that would pull the hub 41 off from the shaft 11, the contact surface 50 of the hub 41 does not push the snap ring 51 back into the annular groove 24, but instead forces it against the edge 60 between the annular groove step 55 and the flank 31 closer to the end of the shaft. An axial load exerted between the hub 41 and shaft 11 that would pull the hub 41 off can crush the securing ring 51 so that it becomes completely wedged, thus possibly also causing damage to the internal splining 43 of the hub 41 if a forced removal is attempted. Fig. 2 is an enlarged depiction of the arrangement according to the invention of a shaft, securing ring, and hub according to Fig. 1 in a non-detachable embodiment of the arrangement. Fig. 3 shows a shaft 11, a hub 41, and a securing ring 51 in which the following details are visible. On the shaft 11, from right to left of the broken view of the shaft body 21, an external splining 23 and an annular groove 24 are visible. The shaft 11 with the external splining 23 ends with a bevel 26 at the end surface 27, which can also conceptually be referred to as the end of the shaft. The external splining 23 ends at a spline end 59 in which the spline grooves come to an end. The annular groove 24 has a steep radial flank 30 on the side closer to the main body of the shaft, a cross-sectionally rounded groove bottom adapted to the securing ring, and a steep radial flank 31 whose height corresponds to the height of the radial flank 30. The hub 41 has a ball track, not shown, which is of no further significance to the connection, and an internal splining 43 that engages the external splining 23 in a form-locked manner in the rotation direction. The drawing also shows that the hub has an end surface 44 oriented toward the main body of the shaft and an end surface 47 oriented toward the end of the shaft, which are conceptually equivalent to the respective ends. Starting from the end surface 44 oriented toward the main body of the shaft, the hub 41 contains an internal cone 45 whose opening angle can correspond to the inclination angle of the spline end 59 of the external splining 23. In addition, an internal cone is provided, which constitutes a bevel 46 that has a large inclination angle on the internal splining 43, cooperates with the spline end 28, and constitutes a first stop means that prevents the hub from sliding further onto the shaft when the structurally determined end position has been reached. Alternatively, this could also occur, for example, in the region of the internal cone 45, which would cooperate with the inclined end 59 to constitute a first stopping means. At the end surface 47 of the hub 41 oriented toward the end of the shaft, the hub has a recess 48 that on the one hand, provides a cylindrical circumference surface 49 and on the other hand, provides a conical stop surface 50 for the securing ring. The diameter of the recess can be less than the root diameter of the internal splining 43 so that the surfaces 49 and 50 can be interrupted by the spline grooves of the internal splining 43. In Fig. 3, the internal splining 43 of the hub 41 has been slid axially all the way onto the external splining 23 of the shaft 11. The securing ring 51 contained in the annular groove 24 here presses radially outward under its own inherent stress. When the hub is being slid into place, the internal cone 45 and the internal splining 43 adjoining it press the securing ring 51 into the bottom of the groove. The internal cone surface 45 serves as an insertion bevel and the radial surface of the flank 30 serves as an opposing or guiding surface. The hub 41 is slid until the bevel 46 of the internal splining 43 comes into contact with the spline end 28 of the external splining 23. The securing ring 51 springs out from the groove bottom and rests with its outside against the inner cylindrical surface 49. The embodiment of the annular groove 24 according to the invention assures that the hub 41 can be nondestructively detached from the shaft 11 since when axial tensile forces are exerted between the hub 41 and the shaft 11 that would pull the hub 41 off from the shaft 11, the contact surface 50 of the hub 41 pushes the snap ring 51 back into the annular groove 24, the flank 31 serving as an opposing or guiding surface. Fig. 4 is an enlarged depiction of the arrangement according to the invention of a shaft, securing ring, and hub according to Fig. 1 in a non-detachable [sic] embodiment of the arrangement. Claims 1. Arrangement having a shaft (11) with an external splining (23) of a limited length that is embodied at a shaft end; having a hub (41) with an internal splining (43) that extends essentially the length of the hub (41) - the external splining (23) and the internal splining (43) engaging each other to permit a transmission of torque between the shaft (11) and hub (41); having a first axial securing means that functions between the shaft (11) and hub (41), prevents the hub (41) from sliding further onto the shaft (11), and is comprised of a stop surface on the hub (41) and a counterpart surface on the shaft (11) or a part connected to it at the end (44) of the hub (41) oriented toward the main body of the shaft; and having a second axial securing means that functions between the shaft (11) and hub (41), prevents the hub (41) from being pulled off from the shaft (11), and includes a securing ring (51) that is situated at the end (27) of the shaft and the end (47) of the hub (41) oriented toward the shaft end and that engages in radial recesses (48, 54) in the shaft (11) and hub (41), which recesses (48, 54) constitute the contact surfaces for this securing ring (51) on the shaft (11) and hub (41), characterized in that the radial recess (54) in the shaft (11) constitutes a first stop surface for the securing ring (51), where the radial recess (54) is embodied in the form of an annular groove (24) with an annular groove diameter d1 and is adjoined in the direction toward the shaft end (27) by an annular groove step (55) with an annular groove step diameter d2 and where d2 is greater than d1; the end (47) of the hub (41) oriented toward the shaft end contains an expanding turned groove (48), which constitutes a second stop surface for the securing ring (51); and the securing ring (51) is embodied in the form of a round snap ring. 2. Arrangement according to claim 1, characterized in that the annular groove step diameter d2 is smaller than the root diameter of the external splining (23) of the shaft (11). 3. Arrangement according to one of claims 1 or 2, characterized in that the gap width of the annular groove (24) is greater than or equal to (>) the diameter of the ring cross section of the securing ring (24) [sic] and the gap width of the annular groove step (55) is less than or equal to (>) the diameter of the ring cross section of the securing ring (24). 4. Arrangement according to one of claims 1 through 3, characterized in that the gap width of the annular groove (24) is greater than the gap width of the annular groove step (55). 5. Arrangement according to one of claims 1 through 4, characterized in that the gap width of the annular groove (24) is approximately twice as great as the gap width of the annular groove step (55). 6. Arrangement according to one of claims 1 through 5, characterized in that the annular groove (24) has a flank (30) that is perpendicular to the shaft axis and closer to the main body of the shaft and has a perpendicular flank (31) closer to the end of the shaft, and the annular groove step (55) has a perpendicular flank (57) closer to the end of the shaft. 7. Arrangement according to one of claims 1 through 6, characterized in that the diameter of the ring cross section of the securing ring (24) is greater than the distance between the groove bottom (58) of the annular groove step (55) and the circumference surface (49) of the recess (48). 8. Arrangement according to one of claims 1 through 7, characterized in that the first axial securing means includes a spline end (28) of the external splining (23) and a corresponding spline bevel (46) at the end of the internal splining (43) in the hub (41) oriented toward the main body of the shaft. 9. Arrangement according to one of claims 1 through 8, characterized in that the internal splining (43) and the external splining (46) [sic] are hardened by means of heat treatment processes and the annular groove (24) and/or the annular groove step (55) are not hardened. 10. Method for manufacturing a shaft for an arrangement according to one of claims 1 through 9, characterized in that starting from a straight, smooth cylindrical shaft, first an annular groove (24) and an annular groove step (55) are cut into the shaft end in arbitrary sequence, spaced slightly apart from the shaft end (27), and then the external splining (23) is produced without this causing any function-influencing changes to the annular groove (24) and the annular groove step (55). 11. Method according to claim 10, characterized in that the external splining (23) is produced by means of a spline die, starting from the annular groove (24) and continuing on to the spline end (28) in the shaft body (21), using an axial pressing process. 12. Method according to claim 10, characterized in that the external splining (23) is rolled into the shaft by means of beading dies. 13. Method according to claim 10, characterized in that the annular groove (24) and/or the annular groove step (55) is/are manufactured in a single clamping setup of the shaft (11), together with all other lathe work processes performed on the shaft (11). 14. Method according to claim 11, characterized in that the process step of manufacturing the external splining (23) is the final machining step performed on the shaft (11).

Documents:

3614-delnp-2007-Abstract-(30-08-2012).pdf

3614-delnp-2007-abstract.pdf

3614-delnp-2007-Claims-(30-08-2012).pdf

3614-delnp-2007-claims.pdf

3614-DELNP-2007-Correspondance Others-(12-02-2015).pdf

3614-delnp-2007-Correspondance Others-(12-12-2014).pdf

3614-delnp-2007-Correspondence Others-(16-01-2015).pdf

3614-delnp-2007-Correspondence Others-(30-08-2012).pdf

3614-DELNP-2007-Correspondence-121214.pdf

3614-delnp-2007-correspondence-others 1.pdf

3614-DELNP-2007-Correspondence-Others-(22-02-2011).pdf

3614-delnp-2007-correspondence-others.pdf

3614-DELNP-2007-Description (Complete)-(12-02-2015).pdf

3614-delnp-2007-description (complete).pdf

3614-delnp-2007-Drawings-(30-08-2012).pdf

3614-delnp-2007-drawings.pdf

3614-delnp-2007-form-1.pdf

3614-delnp-2007-form-18.pdf

3614-delnp-2007-form-2.pdf

3614-DELNP-2007-Form-3-(22-02-2011).pdf

3614-delnp-2007-Form-3-(30-08-2012).pdf

3614-delnp-2007-form-3.pdf

3614-delnp-2007-form-5.pdf

3614-delnp-2007-GPA-(16-01-2015).pdf

3614-delnp-2007-GPA-(30-08-2012).pdf

3614-delnp-2007-Others-(12-02-2015).pdf

3614-delnp-2007-pct-301.pdf

3614-delnp-2007-pct-306.pdf

3614-delnp-2007-pct-308.pdf

3614-delnp-2007-Petition-137-(30-08-2012).pdf

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