Title of Invention	"METHOD FOR SHAPING AN ASSEMBLING ELEMENT AND ASSEMBLING ELEMENT"
Abstract	The invention relates to a method for shaping a contact surface (6, 6a, 6b) and a countercontact surface (7, 7a, 7b) of an assembling element which consists of at least two components for transferring a pressure load from a first component (1) into at least one second component (2, 2a, 2b). To reduce local stress peaks which occur under pressure load, it is proposed that an overlap region (5) of a geometric supporting surface (3) of a first component (1) and of a geometric supporting surface (4) of a second component (2, 2a, 2b) be defined as a contact surface (6, 6a, 6b) of the first component and as a countercontact surface (7, 7a, 7b) of the second component in terms of their geometric extent, the contact surface and the countercontact surface overlapping one another completely, and that clearances be formed, starting from the limits of the defined contact surface and countercontact surface, those regions of the supporting surfaces of the first and of the second component which project beyond the contact surface and the countercontact surface being spatially offset from the contact surface and the countercontact surface. The invention relates, further, to an assembling element produced according to the method.

Title of Invention

"METHOD FOR SHAPING AN ASSEMBLING ELEMENT AND ASSEMBLING ELEMENT"

Abstract

The invention relates to a method for shaping a contact surface (6, 6a, 6b) and a countercontact surface (7, 7a, 7b) of an assembling element which consists of at least two components for transferring a pressure load from a first component (1) into at least one second component (2, 2a, 2b). To reduce local stress peaks which occur under pressure load, it is proposed that an overlap region (5) of a geometric supporting surface (3) of a first component (1) and of a geometric supporting surface (4) of a second component (2, 2a, 2b) be defined as a contact surface (6, 6a, 6b) of the first component and as a countercontact surface (7, 7a, 7b) of the second component in terms of their geometric extent, the contact surface and the countercontact surface overlapping one another completely, and that clearances be formed, starting from the limits of the defined contact surface and countercontact surface, those regions of the supporting surfaces of the first and of the second component which project beyond the contact surface and the countercontact surface being spatially offset from the contact surface and the countercontact surface. The invention relates, further, to an assembling element produced according to the method.

Full Text	Description Method for shaping an assembling element and assembling element The invention relates to a method for shaping a contact surface and a countercontact surface of an assembling element which consists of at least two components for transferring a pressure load from a first component into at least one second component. The invention relates further to an assembling element employing the method according to the invention which consists of two components for transferring a pressure load from a first component into a second component the first component having a contact surface which bears against a countercontact surface of the second component. Assembling elements of the type according to the invention are particularly suitable for transferring a force for example a supporting force or a moment in particular a torque from a first component to a second component. According to one possible embodiment this is a shaft/hub assembly the hub being fastened on the shaft with a press fit or with a shrink fit. According to a further embodiment one component is a pressure-exerting component for example a pressure ram a pressure screw or the piston rod of a pressure medium cylinder and the further component is a supporting element for example a frame or a similar component which counteracts the applied force. In a roll stand the first component may be formed for example by a roll stand column and the second component may be formed for example by a threaded nut with threaded spindle supported on the roll stand column. Particularly where shaft/hub assemblies are concerned it is known from practical damage situations and from experimental tests that the tension and pressure distribution in the press assembly has marked stress peaks and the pressures are substantially higher particularly in the vicinity of the end faces of a press assembly than in the middle region of the parting plane. These pressures lead to damage in these edge regions which subsequently leads to plastic deformations and to crack formations and in extreme cases to permanent breaks on the components. These damaging stress peaks are caused by minor manufacturing errors and elastic deformations under operating load. The manual by Franz G. Kollmann; "Welle-Nabe-Verbindung Gestaltung Auslegung Auswahl" ["Shaft/hub assembly configuration design and selection"]/ Springer Verlag 1984 p. 50-59 and 72-80 refers to these locally narrowly limited deviations in joint pressure and the additional stress peaks at the edges and indicates the influence of shaping on the joint pressure for a multiplicity of embodiments of a shaft/hub assembly. The shaping guidelines resulting from this are extremely multilayered. In addition to proposals as regards peak-to-valley height and the form and position tolerances according to DIN standardization one proposal relates to the design of a shaft shoulder with a predetermined transition radius. However this shaping proposal too is not generally valid. The object of the present invention therefore is to avoid the above-described disadvantages of known assembling elements and to propose a method for shaping a contact surface and a countercontact surface of an assembling element in which the pressure load can be kept largely constant and in particular stress peaks in the edge regions of the contact surfaces are largely avoided. A further object is to increase substantially the fatigue strength of the assembling element and reliably to avoid permanent breaks. Proceeding from a method of the type initially mentioned this object is achieved in that an overlap region of a geometric supporting surface of a first component and of a geometric supporting surface of a second component is defined as a contact surface of the first component and as a countercontact surface of the second component in terms of their geometric extent the contact surface and the countercontact surface overlapping one another completely and in that clearances are formed starting from the limits of the defined contact surface and countercontact surface those regions of the supporting surfaces of the first and of the second component which project beyond the contact surface and the countercontact surface being spatially offset from the contact surface and the countercontact surface. A supporting surface of the first and of the second component is to be understood as meaning the edgelessly continuous planar or spatially curved surfaces of the two components to be pressed against one another said surfaces comprising the contact surface of the first component and the countercontact surface of the second component before they are formed or delimited by the method according to the invention. Each of the supporting surfaces may already correspond in its geometric extent in part regions to the contact surfaces while one of the two supporting surfaces may also correspond entirely to the defined contact surface. The delimitation of two planar or spatially curved contact surfaces within the overlap region of the opposite supporting surfaces determines the surfaces which later have to ensure force or moment transmission. Each of these contact surfaces is delimited with respect to the projecting parts of the supporting surface by means of clearances which are formed in a preferred way. Clearances are made that is to say clearance surfaces formed at all the margins (edges) of the contact surface and of the countercontact surface thus ensuring that stress peaks are substantially reduced or even avoided. The clearances adjoining the contact surface and the countercontact surface are formed by clearance surfaces which at the tangent line with the contact surface and the countercontact surface run in each case approximately perpendicularly with respect to this and with respect to the remaining supporting surface form a notch. This notch is in this context to be understood as meaning a rounding-out. The clearance surfaces delimit the contact surface and the countercontact surface entirely with respect to further surfaces of the two components and thus form a closed annular region around the contact surface or countercontact surface. Since the clearance surfaces run essentially perpendicularly with respect to the relevant contact surface at the tangent line with the latter the two clearance surfaces adjoining the contact surface and the countercontact surface form a unitarily spatially curved clearance surface. With the clearance surface running away from the contact margin perpendicularly with respect to the contact surface the prevailing singular stress concentration problem at the contact margins is solved and is reduced to a notch stress problem of the clearance surface which can be optimized by means of normal computational software. The clearance or clearance surface is expediently designed with a contour which in cross section forms approximately a segment of an ellipse or a three-center curve. In contrast to a clearance surface based on a fixed rounding-out radius the proposed curve profiles achieve a radius profile in the clearance surface which at least in steps decreases and subsequently increases again. A contribution to minimizing stress peaks in the components is thereby likewise achieved. Taking into account economic possibilities in manufacturing terms the general notch form found by up-to-date optimization software of the clearance surface is expediently approximated by a sequence of notch arcs and straight lines. In an assembling element which consists of three components and in which force or moment transmission takes place between a first component and the two further components and the three components are assembled such that they touch one another along a straight or curved contact line high pressure and tensile stress peaks arise in the components particularly in the region surrounding this contact line. In these instances a substantial equalization of the stress conditions can be achieved if clearance surfaces are formed along the common contact line which in the case of a curved contact line form a closed toroidal annular space or in the case of a straight contact line form a clearance channel of closed cross section which in its longitudinal extent surrounds the contact line. A further equalization of the loads on the cooperating components at the contact surface and countercontact surface is achieved in that at least one of the contact surface or countercontact surface is provided with a camber. Depending on the load situation and the need the camber extends over the entire contact surface or countercontact surface or else only over a part region of one of these two contact surfaces. Further designs advantageous for stress equalization of the cambers on the contact surface or the countercontact surface are achieved if the contour of the camber of the contact surface or of the countercontact surface is shaped in at least one cross section with an at least partially convex and continuously differentiatable curve. A further possibility for favorably influencing the stress distribution is for the contour of the camber of the contact surface or countercontact surface to be formed in at least one cross section from at least two continuously differentiatable curve segments of which at least one curve segment is equipped with a convex curve profile the continuous differentiatability being afforded at the transition point of adjacent curve segments. In a development of this embodiment the contour of the camber of the contact surface or countercontact surface is formed by three curve segments the middle curve segment being formed by a straight line and the adjacent curve segments being formed by convexly curved curves. Likewise to achieve a uniform stress distribution it is expedient if the contour of the camber of the contact surface or countercontact surface is shaped in at least one cross section with a curve having a double-convex preferably symmetrical profile. For the transmission of torques the first component forms with the contact surface and the second component with the countercontact surface a shrink assembly. Preferred applications for this are shaft/hub assemblies the first component being formed by a driveable shaft and the second component being formed by a torque-transmitting element such as a gearwheel friction wheel driving wheel or the like. In a special application from rolling mill technology the first component is formed by a roll stand column with a blind hole bore arranged centrally in the crosshead and the second component is formed by a threaded nut with threaded spindle supported axially in the blind hole bore. Employing the method according to the invention the present invention comprises an assembling element consisting of at least two components for transferring a pressure load from a first component into at least one second component the first component having a contact surface which bears against a countercontact surface of the second component. This assembling element is characterized in that the contact surface and the countercontact surface overlap one another completely and clearances or clearance surfaces start at all the margins of the contact surface and of the countercontact surface. Preferably at least one of the contact surface or countercontact surface has a camber which extends over the entire region of one of the contact surfaces or over at least a part region of a contact surface. Cambers on both contact surfaces of the two components said contact surfaces lying opposite one another and being pressed against one another in the operating state are likewise possible. The clearances on the contact surface and the countercontact surfaces are formed by clearance surfaces which at the tangent line with the contact surface and the countercontact surface are in each case approximately perpendicular with respect to this and in the case of spatially curved clearance surfaces form notches. The notches are provided in a special way with a contour in order to ensure stress peak minimization. Accordingly the clearances or clearance surfaces have a contour which is formed in one cross section approximately by a segment of an ellipse or by a three-center curve. components and in which the components touch one another along a common contact line clearance surfaces are arranged which form a closed toroidal annular space or a clearance channel of closed cross section which in its longitudinal extent surrounds the contact line. The cross-sectional contour of the toroidal annular space or of the clearance channel of closed cross section is formed by curved lines. The contour of the camber of the contact surface or countercontact surface is formed in at least one cross section by an at least partially convex and continuously differentiatable curve. Alternatively the contour of the camber of the contact surface or countercontact surface may be formed in at least one cross section from at least two continuously differentiatable curve segments of which at least one curve segment has a convex curve profile the continuous differentiatability being afforded at the transition point of adjacent curve segments. Further the contour of the camber of the contact surface or countercontact surface may also be formed by three curve segments the middle curve segment being formed by a straight line and the adjacent curve segments being formed by convexly curved curves. A further possible embodiment is for the contour of the camber of the contact surface or countercontact surface to be formed in at least one cross section by a curve having a double-convex preferably symmetrical profile. The proposed assembling element offers a multiplicity of possibilities for use in various fields of technology. According to a preferred group of possibilities for use which relate to the basic element of a shaft/hub assembly the first component is formed by a driveable shaft which is coupled for example to a motor and the second component is formed by a torque-transmitting element such as a gearwheel a friction wheel a driving wheel or the like. In this case the first component forms with the contact surface and the second component with the countercontact surface a shrink assembly. A further preferred group of applications relates to the design of the contact surfaces of a pressure ram and of the counteracting supporting surface of a supporting element. A preferred concrete embodiment relates to the basic structure of a roll stand. In concrete terms the first component is formed by a roll stand column with a blind hole bore arranged centrally in the crosshead and the second component is formed by a pressure nut with threaded spindle supported axially in the blind hole bore. Further advantages and features of the present invention arise from the following description of unrestrictive exemplary embodiments reference being made to the accompanying figures in which: fig. la shows a generalized illustration of an assembling element with a defined contact surface and countercontact surface fig. Ib shows the shaping according to the invention of the contact surface and of the countercontact surface according to fig. la fig. Ic shows a further shaping according to the invention of the contact surface and of the countercontact surfaces according to fig. 1 fig. 2a shows a first embodiment of a shaft/hub assembly in a basic design fig. 2b shows the first embodiment of a shaft/hub assembly according to fig. 2a with the shaping according to the invention of the contact surface and of the countercontact surface fig. 3a shows a second embodiment of a shaft/hub assembly in a basic design fig. 3b shows the second embodiment of a shaft/hub assembly according to fig. 3a with the shaping according to the invention of the contact surface and of the countercontact surface fig. 4a shows a third embodiment of a shaft/hub assembly in a basic design fig. 4b shows the third embodiment of a shaft/hub assembly according to fig. 4a with the shaping according to the invention of the contact surface and of the countercontact surface fig. 5a shows a fourth embodiment of an arrangement of a pressure nut in a blind hole bore in a basic design fig. 5b shows the fourth embodiment of an arrangement of a pressure nut in a blind hole bore according to fig. 5a with the shaping according to the invention of the contact surface and of the countercontact surface fig. 5c shows an enlargement of a detail of the edge formation according to the invention of the contact surface and of the countercontact surface fig. 6a shows a fifth embodiment with a shaft/hub assembly having two helically toothed gearwheels in an arrangement on a shaft in which they touch one another on the end faces in a basic design fig. 6b shows the fifth embodiment with a shaft/hub assembly having two helically toothed gearwheels in an arrangement on a shaft in which they touch one another on the end faces with the shaping according to the invention of the contact surface and of the countercontact surface fig. 7a shows a sixth embodiment with three force-transmitting components touching one another fig. 7b shows the sixth embodiment with the shaping according to the invention of the components in a sectional illustration along the line A-A in fig. 7a fig. 7c shows the sixth embodiment with the shaping according to the invention of the components in a sectional illustration along the line B-B in fig. 7a fig. 8a shows a seventh embodiment with an axially releasable assembly of a rolling mill drive fig. 8b shows the seventh embodiment with the shaping according to the invention of the releasable assembly in a rolling mill drive in a partial section fig. 8c shows an inner batten according to the seventh embodiment in the case of an alternating load direction. In fig. la a first component 1 and a second component 2 of an assembling element not defined in any more detail are indicated as abstract parallelepipedal forms and the two components are illustrated at a vertical distance from one another. The supporting surface 3 of the first component 1 and the supporting surface 4 of the second component 2 said supporting surfaces overlapping one another in an overlap region 5 when viewed vertically are directed toward one another. This overlap region is defined as a contact surface 6 illustrated by thick lines on the first component 1 and a corresponding countercontact surface 7 on the second component 2 this contact surface and countercontact surface being pressed against one another under the action of a vertical force F in the subsequent operating state and therefore being designed such that the stress distribution on the contact surfaces and in the region surrounding these contact surfaces takes place as uniformly as possible in the two cooperating components and in particular stress peaks in the marginal regions of the contact surfaces are avoided said stress peaks necessarily occurring in practice when components as illustrated in fig. la are pressed one onto the other without further structure measures. As illustrated in fig. Ib a stress-optimized shaping of the contact surface 6 on the component 1 and of the countercontact surface 7 on the component 2 is achieved in a first step by the formation of clearances or clearance surfaces 8 by means of which the contact surface 6 and the countercontact surface 7 are delimited with respect to the adjoining regions of the supporting surface 3 and of the supporting surface 4. The clearance surfaces 8 start at the contact surfaces 6 7 approximately perpendicularly with respect to these and are transferred in groove form into the supporting surface 3 4. If the contact surfaces 3 4 end at one of the side walls 9 of one of the components there is no need for a special clearance surface to be formed. However as illustrated in fig. Ic the contact surface 6 and the countercontact surface 7 may be dimensioned smaller and in each case a peripheral clearance surface 8 may be incorporated on the contact surface and on the countercontact surface. In a general consideration of a cooperating contact surface and countercontact surface which overlap one another a general marginal contact line is obtained and starting from this general marginal contact line the clearance surface commences with each surface which can be illustrated by straight lines and is formed by that perpendicular which arises from the Cartesian coordinate system when an axis lies along the marginal contact line and an axis lies in the contact surface. The clearance surfaces of the cooperating components are determined by means of up-to-date optimization software and are expediently approximated in manufacturing terms by means of a sequence of three-centered curves and straight lines. The design of the clearance surfaces in this case takes place individually for each component and takes into account the local stress conditions. The countercontact surface 7 illustrated in fig. Ib is designed with a camber 24 in the X-direction and in the Y-direction starting from a planar middle region so as in each case to have a camber descending towards the margins of the countercontact surface and is indicated by thin lines. This measure too contributes substantially to reducing stress peaks in the marginal zones. Figures 2a to 4b and 6a 6b illustrate advantageous embodiments of the shaping according to the invention of a shaft/hub assembly the shaft constituting the first component 1 and the hub the second component 2 of the assembling element. The shaft and hub are assembled by means of a shrink assembly and are suitable especially for the transmission of torques. The shaping according to the invention of the contact and countercontact surfaces is to be illustrated in more detail by means of this in no way restrictive choice of possible assemblies. In the design illustration according to fig. 2a a component 2 formed by a hub is shrunk on a component 1 constituting a shaft the hub being connected only over a part length of its longitudinal extent to the shaft. The cylindrical inner wall of the hub forms the supporting surface 3 of the component 2 and the cylindrical surface area of the shaft forms the supporting surface 4 of the component 1. In the overlap region of the two supporting surfaces 3 4 the cooperating contact surfaces 6 of the component 1 and countercontact surface 7 of the component 2 are defined and these defined surfaces must overlap one another entirely. Fig. 2b illustrates the shaping of clearance surfaces starting from the margins of the contact surface 6 and countercontact surface 7. According to the invention the clearance surfaces starting from the margins of the two contact surfaces are oriented perpendicularly with respect to these and are led back in the form of an arc to the respective supporting surface 2 3. Accordingly a clearance surface 8a starting from the edge 10 is produced as a recess into the shaft (component 1) and a clearance surface 8b starting from the edge 11 is produced as a recess into the hub (component 2) . The vertical end faces adjoining the contact surface and countercontact surface of the first and the second component require no particular clearance at the contact surface and countercontact surface. The design illustration according to fig. 3a shows a shaft/hub assembly in which a cylindrical component 2 (hub) is shrunk onto a cylindrical component 1 (shaft) and the component 2 is fastened at a shaft shoulder in alignment with the end wall on the shaft portion having the larger diameter. It is necessary here to arrange a clearance surface 8a in the manner of a recess into the component 1 adjacently to the defined contact surface 6 of the component 1. End faces 12 13 oriented perpendicularly with respect to the contact surface 6 and margin of these contact surfaces so that a special clearance is not necessary here. However a rounding-out is provided on the shaft shoulder as corresponds to conventional design practice. The design illustration according to fig. 4a again shows a shaft/hub assembly with a stepped shaft which forms the component 1 and with a hub which forms the component 2 the hub being shrunk on the shaft journal having the smaller diameter and bearing against the end face 14 of the shaft. This embodiment requires a special fixing of the contact surface and countercontact surface in the region of the shaft shoulder since by the hub bearing against the end face 14 of the shaft -lithe stress conditions in this region are disturbed to a particular extent. This is illustrated in fig. 4b. In order to provide space for arranging the clearance surfaces in the shoulder region of the shaft the contact surface 6 and the countercontact surface 7 commence only at a distance a from the end face 14. Starting from the margins of the contact surface 6 of the shaft toroidal clearance surfaces 8a 8b are formed by a turned groove or by a recess into the shaft the clearance surface 8a merging arcuately into the end face 14. The clearance surface 8c which starts from the countercontact surface 7 is of arcuate design and ends on the end face 15 of the hub. Overall a toroidal free space in the critical edge region is provided. A further exemplary embodiment from rolling mill technology illustrated in a design illustration in fig. 5a relates to a roll stand in particular to the contact zone of the crosshead of a roll stand column 16 and of a pressure nut 17 which is supported in a blind hole bore 18 of the roll stand column. In the contact zone of the blind hole bore and pressure nut the rolling force is introduced into the roll stand column via a threaded spindle and the pressure nut. During load transmission normally high pressure and tensile stress zones occur locally next to one another. Owing to an optimal shaping of the contact region both zones can achieve a largely uniform comparative stress at a low level and consequently ensure the highest possible reliability against permanent breakage. In a conventional structure configuration as illustrated in fig. 5a considerable comparative stress peaks causing permanent load damage arise in the regions surrounding the edges 19 and 20 both in the pressure nut 17 and in the crosshead of the roll stand column 16 (in the bottom region of the blind hole bore). As illustrated enlarged in fig. 5b and 5c a contact surface 6 and a countercontact surface 7 which offer sufficient space for the formation of clearance surfaces 8a 8b 8c are defined on the pressure nut 17 and the cross head of the roll stand column 16 on the opposite supporting surfaces 3 4. The essentially rotationally symmetrical pressure nut 17 is equipped in the contact region of a blind hole bore with a peripheral toroidal clearance surface 8a which starting from the end countercontact surface 7 runs commencing perpendicularly with respect to the latter arcuately to the side wall 21. The contour of this clearance surface 8a corresponds to a rounding-out radius r. A clearance surface 8c is likewise formed on the pressure nut in the region of the through bore of the roll stand column. Since the contact surface 6 and the countercontact surface 7 overlap one another entirely the clearance surface 8b in the crosshead starts on the contact surface 6 so as to directly adjoin the clearance surface 8a (edge 22). The clearance surface 8b extends at least along the edge with the contact surface 6 perpendicularly with respect to the latter and runs arcuately as far as the edge 23 where it coincides again with the clearance surface 8a. The clearance surface 8b is formed by a segment of a three-centered curve which has a radius of curvature ri in a first region and a radius of curvature r2 in a second region. By virtue of this special shaping the peak values of the comparative stresses particularly the tensile stress peaks are greatly reduced and equalized in the optimization range in relation to an embodiment according to fig. 5a.The design illustration according to fig. 6a shows a shaft forming the component 1 with a supporting surface 3 and with two radially shrunk-on gearwheels with supporting surfaces 4a 4b which form the components 2a 2b the two gearwheels being arranged so as to lie closely against one another and the end faces. In this embodiment there is 3-body contact in which the three components 1 2a 2b meet with their supporting surfaces 3 4a 4b along a contact line L and the stress conditions in this region are particularly disturbed due to the mutual support of the individual components. Singular stress concentrations at the hub margin of the joint surfaces arise. It is therefore particularly important starting from the contact line L which forms a singularity to define the contact surfaces 6a 6b on the component 1 and the countercontact surfaces 7a 7b on the components 2a 2b and also the necessary clearance surfaces on the three components. These clearances are illustrated in more detail in fig. 6b. Starting from the edges 10 and 11 of the contact surfaces 6a and 7a and 6b and 7b which overlap one another in pairs clearance surfaces 8a 8b 8c 8d are formed which are oriented at the edges 10 11 perpendicularly with respect to the contact surfaces and form a closed toroidal annular space 16 and which include the singularity L. The clearances 8e 8f on the contact line of the two outer end faces of the gearwheel-forming components 2a 2b with the shaft are designed similarly to the exemplary embodiment according to figures 2b 3b or 4b. The design illustration according to fig. 7a shows the cooperation of three components 1 2a 2b by means of a sixth embodiment two further components 2a 2b being supported with their supporting surfaces 4a 4b on a supporting surface 3 of a component 1. The components 2a 2b touch one another in each case with a further side surface.The force action F takes place perpendicularly with respect to the supporting surfaces of the components. In this embodiment there is likewise 3-body contact in which the three components meet with their supporting surfaces along a contact line L and the stress conditions in this region are particularly disturbed due to the mutual support of the individual components. It is therefore particularly important starting from the contact line L which forms a singularity to define the contact surfaces 6a 6b on the component 1 and the countercontact surfaces la 7b on the components 2a 2b and also the necessary clearance surfaces on the three components. These clearances are partially illustrated in more detail in figures 7b and 7c fig. 7b showing a sectional illustration along the sectional line A-A in fig. 7a and fig. 7c showing a sectional illustration along the sectional line B-B in fig. 7a. Starting from the edges 10 11 (fig. 7b) of the contact surfaces 6a and 7a and 6b and 7b overlapping one another in pairs clearance surfaces 8a 8b 8c 8d are formed which are oriented at the edges 10 11 perpendicularly with respect to the contact surfaces and which form a clearance channel 31 of closed cross-section and include the singularity L. In addition starting from the edges 25 26 27 28 29 30 clearance surfaces are arranged which form a closed groove-shaped clearance in the component 1 the clearance surfaces 8e 8f 8g 8h being illustrated. All clearance surfaces not illustrated are designed similarly.The design drawing according to fig. 8a shows by the example of a rolling mill drive for a working roll in cross section a drive shaft with a flat journal 41 which projects into a central recess of a cylindrical coupler 42 which is itself equipped with two inner battens 43 44. A play s for the easy axial assembling and separation of the components of the drive system is provided between the cheeks 45 46 of the flat journal 41 and the supporting surfaces 47 48 of the inner battens. When the drive moment is applied and under load a tilting of the flat journal occurs between the inner battens so that linear or point contact of the longitudinal edges 50 51 of the flat journal on the supporting surfaces 47 48 of the inner battens arises and consequently high surface pressure and stress peaks occur in this contact region of the components. The play s prevents the cheeks 45 46 of the flat journal from bearing over a large area against the supporting surfaces 47 48 of the two inner battens. In order to achieve an optimization of the stress conditions with the effect of equalizing the surface pressure in the assembling element it is necessary as illustrated in fig. 8b to coordinate the contact surface 52 on the cylindrical coupler 42 and the opposite countercontact surface 53 on the inner batten 43 with one another so thata mutual overlap of these surfaces is achieved and to define clearance surfaces 8a 8b with an optimized contour starting from the edge 10. This takes place as already described in the preceding exemplary embodiments. The supporting surface 47 of the inner batten 43 is to be arranged with an inclination at an angle e to the vertical which compensates the predetermined play s between the inner batten 43 and the cheek 45 in the nonloaded state of the assembling element and ensures that the cheek bears over a large area against the supporting surface of the inner batten. Further as in the preceding exemplary embodiments the supporting surface 47 of the inner batten 43 is to be coordinated with the surface of the cheek 45 with the effect of a mutual overlap and a corresponding clearance surface 8c with an optimized contour starting from the edge 11 is to be formed. In the case of a changing direction of rotation and therefore a changing load direction the inner battens are to be designed according to fig. 8c.In the configuration of an asembly according to the invention of components it is not important in the cooperation of two components or of three components whether the contact surfaces and the countercontact surfaces are formed by planar surfaces or by spatially curved surfaces (preferably cylindrical surfaces) nor is the geometric form of these surfaces (rectangular square round annular or the like) important but solely the complete overlap and the configuration of the clearance surfaces starting from the edges of the contact surface and countercontact surface.In all the embodiments described by way of example an additional equalization of the surface pressure and therefore of the comparative stress conditions can be achieved via thecontact surface and countercontact surface by a cambered design of at least one of the contact surface or countercontact surface. Patent Claims: 1. A method for shaping a contact surface (6, 6a, 6b) and a countercontact surface (7, la, 7b) of an assembling element which consists of at least two components for transferring a pressure load from a first component (1) into at least one second component (2, 2a, 2b) , characterized in that an overlap region (5) of a geometric supporting surface (3) of a first component (1) and of a geometric supporting surface (4, 4a, 4b) of a second component (2) is defined as a contact surface (6, 6a, 6b) of the first component and as a countercontact surface (7, 7a, 7b) of the second component in terms of their geometric extent, the contact surface and the countercontact surface overlapping one another completely, and in that clearances are formed, starting from the limits of the defined contact surface and countercontact surface, those regions of the supporting surfaces of the first and of the second component which project beyond the contact surface and the countercontact surface being spatially offset from the contact surface and the countercontact surface. 2. The method as claimed in claim 1, characterized in that the clearances on the contact surface and the countercontact surface are formed by clearance surfaces (8, 8a, 8b, 8c, 8d, 8e, 8f, 8g, 8h) which at the tangent line with the contact surface and the countercontact surface run in each case approximately perpendicularly with respect to this and with respect to the remaining supporting surface form a notch. 3. The method as claimed in claim 1 or 2, characterized in that the clearances are designed with a contour which in cross section form approximately a segment of an ellipse. 4. The method as claimed in claim 1 or 2, characterized in that the clearances are designed with a contour which in cross section form approximately a three-center curve. 5. The method as claimed in one of the preceding claims, characterized in that, in the case of an assembling element consisting of three components (1, 2a, 2b) , clearance surfaces (8a, 8b, 8c, 8d) are formed along a common contact line (L) , which form a closed toroidal annular space (16) or a clearance channel (31) of closed cross section which in its longitudinal extent surrounds the contact line (L) . 6. The method as claimed in one of the preceding claims, characterized in that at least one of the contact surface or countercontact surface is provided with a camber (24). 7. The method as claimed in claim 6, characterized in that the contour of the camber (24) of the contact surface or of the countercontact surface is shaped in at least one cross section with an at least partially convex and continuously differentiatable curve. 8. The method as claimed in claim 6 or 7, characterized in that the contour of the camber (24) of the contact surface or countercontact surface is formed in at least one cross section from at least two continuously differentiatable curve segments, of which at least one curve segment has a convex curve profile, the continuous differentiatability being afforded at the transition point of adjacent curve segments. 9. The method as claimed in claim 6 or 7, characterized in that the contour of the camber (24) of the contact surface or countercontact surface is formed by three curve segments, the middle curve segment being formed by a straight line and the adjacent curve segments being formed by convexly curved curves. 10. The method as claimed in claim 6 or 7, characterized in that the contour of the camber (24) of the contact surface or countercontact surface is shaped in at least one cross section with a curve having a double-convex, preferably symmetrical profile. 11. The method as claimed in one of the preceding claims, characterized in that the first component forms with the contact surface and the second component with the countercontact surface a shrink assembly. 12. The method as claimed in claim 11, characterized in that the first component is formed by a driveable shaft and the second component is formed by a torque-transmitting element, such as a hub, gearwheel, friction wheel or driving wheel. 13. The method as claimed in one of the preceding claims 1 to 10, characterized in that the first component is formed by a roll stand column (16) with a blind hole bore arranged centrally in the crosshead, and the second component is formed by a pressure nut (17) with threaded spindle supported axially in the blind hole bore. 14. An assembling element, consisting of at least two components for transferring a pressure load from a first component (1) into at least one second component (2), the first component having a contact surface (6, 6a, 6b) which bears against a countercontact surface (7, 7a, 7b) of the second component, produced by a method as claimed in one of claims 1 to 12, characterized in that the contact surface and countercontact surface overlap one another completely, and in that clearances (8, 8a, 8b, 8c, 8d, 8e, 8f, 8g, 8h) start at all the margins of the contact surface and of the countercontact surface. 15. The assembling element as claimed in claim 14, characterized in that the clearances on the contact surface and the countercontact surfaces are formed by clearance surfaces (8, 8a, 8b, 8c, 8d, 8e, 8f) which at the tangent line with the contact surface and the countercontact surface are in each case approximately perpendicular with respect to this and in the case of spatially curved clearance surfaces form notches. 16. The assembling element as claimed in claim 14 or 15, characterized in that the clearance surface has a contour which is formed in one cross section approximately by a segment of an ellipse. 17. The assembling element as claimed in claim 14 or 15, characterized in that the clearance surface has a contour which is formed in one cross section approximately by a three-center curve. 18. The assembling element as claimed in one of claims 14 to 17, characterized in that, in the case of an assembling element consisting of three components (1, 2a, 2b), clearance surfaces (8a, 8b, 8c, 8d) are arranged along a common contact line (L) , which form a closed toroidal annular space (16) or a clearance channel (31) of closed cross section which in its longitudinal extent surrounds the contact line (L). 19. The assembling element as claimed in one of claims 14 to 18, characterized in that at least one of the contact surface and countercontact surface has a camber (24). 20. The assembling element as claimed in claim 19, characterized in that the contour of the camber of the contact surface or countercontact surface is formed in at least one cross section by an at least partially convex and continuously differentiatable curve. 21. The assembling element as claimed in claim 19 or 20, characterized in that the contour of the camber of the contact surface or countercontact surface is formed in at least one cross section from at least two continuously differentiatable curve segments, of which at least one curve segment has a convex curve profile, the continuous differentiatability being afforded at the transition point of adjacent curve segments. 22. The assembling element as claimed in claim 19 or 20, characterized in that the contour of the camber of the contact surface or countercontact surface is formed by three curve segments, the middle curve segment being formed by a straight line and the adjacent curve segments being formed by convexly curved curves. 23. The assembling element as claimed in claim 19 or 20, characterized in that the contour of the camber of the contact surface or countercontact surface is formed in at least one cross section by a curve having a double-convex, preferably symmetrical profile. 24. The assembling element as claimed in one of the preceding claims 14 to 23, characterized in that the first component forms with the contact surface and the second component with the countercontact surface a shrink assembly. 25. The assembling element as claimed in claim 24, characterized in that the first component is formed by a driveable shaft and the second component is formed by a torque-transmitting element, such as a hub, gearwheel, friction wheel, driving wheel, etc. 26. The assembling element as claimed in one of the preceding claims 14 to 23, characterized in that the first component is formed by a roll stand column (16) with a blind hole bore (18) arranged centrally in the crosshead, and the second component is formed by a pressure nut (17) with threaded spindle supported axially in the blind hole bore.

Full Text

Description
Method for shaping an assembling element and assembling element
The invention relates to a method for shaping a contact surface and a countercontact surface of an assembling element which consists of at least two components for transferring a pressure load from a first component into at least one second component. The invention relates further to an assembling element employing the method according to the invention which consists of two components for transferring a pressure load from a first component into a second component the first component having a contact surface which bears against a countercontact surface of the second component.
Assembling elements of the type according to the invention are particularly suitable for transferring a force for example a supporting force or a moment in particular a torque from a first component to a second component. According to one possible embodiment this is a shaft/hub assembly the hub being fastened on the shaft with a press fit or with a shrink fit. According to a further embodiment one component is a pressure-exerting component for example a pressure ram a pressure screw or the piston rod of a pressure medium cylinder and the further component is a supporting element for example a frame or a similar component which counteracts the applied force. In a roll stand the first component may be formed for example by a roll stand column and the second component may be formed for example by a threaded nut with threaded spindle supported on the roll stand column.
Particularly where shaft/hub assemblies are concerned it is known from practical damage situations and from experimental tests that the tension and pressure distribution in the press assembly has marked stress peaks and the pressures are substantially higher particularly in the vicinity of the end

faces of a press assembly than in the middle region of the parting plane. These pressures lead to damage in these edge regions which subsequently leads to plastic deformations and to crack formations and in extreme cases to permanent breaks on the components. These damaging stress peaks are caused by minor manufacturing errors and elastic deformations under operating load. The manual by Franz G. Kollmann;
"Welle-Nabe-Verbindung Gestaltung Auslegung Auswahl"
["Shaft/hub assembly configuration design and selection"]/
Springer Verlag 1984 p. 50-59 and 72-80 refers to these
locally narrowly limited deviations in joint pressure and the
additional stress peaks at the edges and indicates the
influence of shaping on the joint pressure for a multiplicity
of embodiments of a shaft/hub assembly. The shaping guidelines
resulting from this are extremely multilayered. In addition to
proposals as regards peak-to-valley height and the form and
position tolerances according to DIN standardization one
proposal relates to the design of a shaft shoulder with a
predetermined transition radius. However this shaping
proposal too is not generally valid.
The object of the present invention therefore is to avoid the above-described disadvantages of known assembling elements and to propose a method for shaping a contact surface and a countercontact surface of an assembling element in which the pressure load can be kept largely constant and in particular stress peaks in the edge regions of the contact surfaces are largely avoided. A further object is to increase substantially the fatigue strength of the assembling element and reliably to avoid permanent breaks.
Proceeding from a method of the type initially mentioned this object is achieved in that an overlap region of a geometric supporting surface of a first component and of a geometric supporting surface of a second component is defined as a contact surface of the first component and as a countercontact surface of the second component in terms of their geometric extent the contact surface and the countercontact surface overlapping one another completely and in that clearances are formed starting from the limits of the defined contact surface and countercontact surface those regions of the supporting surfaces of the first and of the second component which project
beyond the contact surface and the countercontact surface being spatially offset from the contact surface and the countercontact surface.
A supporting surface of the first and of the second component is to be understood as meaning the edgelessly continuous planar or spatially curved surfaces of the two components to be pressed against one another said surfaces comprising the contact surface of the first component and the countercontact surface of the second component before they are formed or delimited by the method according to the invention. Each of the supporting surfaces may already correspond in its geometric extent in part regions to the contact surfaces while one of the two supporting surfaces may also
correspond entirely to the defined contact surface. The delimitation of two planar or spatially curved contact surfaces within the overlap region of the opposite supporting surfaces determines the surfaces which later have to ensure force or moment transmission. Each of these contact surfaces is delimited with respect to the projecting parts of the supporting surface by means of clearances which are formed in a preferred way. Clearances are made that is to say clearance surfaces formed at all the margins (edges) of the contact surface and of the countercontact surface thus ensuring that stress peaks are substantially reduced or even avoided.
The clearances adjoining the contact surface and the countercontact surface are formed by clearance surfaces which at the tangent line with the contact surface and the countercontact surface run in each case approximately perpendicularly with respect to this and with respect to the remaining supporting surface form a notch. This notch is in this context to be understood as meaning a rounding-out. The clearance surfaces delimit the contact surface and the countercontact surface entirely with respect to further surfaces of the two components and thus form a closed annular region around the contact surface or countercontact surface. Since the clearance surfaces run essentially perpendicularly with respect to the relevant contact surface at the tangent line with the latter the two clearance surfaces adjoining the contact surface and the countercontact surface form a unitarily spatially curved clearance surface. With the clearance surface running away from the contact margin perpendicularly with respect to the contact surface the prevailing singular stress concentration problem at the contact margins is solved and is reduced to a notch stress problem of the clearance surface which can be optimized by means of normal computational software.
The clearance or clearance surface is expediently designed with a contour which in cross section forms approximately a segment of an ellipse or a three-center curve. In contrast to a clearance surface based on a fixed rounding-out radius the proposed curve profiles achieve a radius profile in the clearance surface which at least in steps decreases and subsequently increases again. A contribution to minimizing stress peaks in the components is thereby likewise achieved.
Taking into account economic possibilities in manufacturing terms the general notch form found by up-to-date optimization software of the clearance surface is expediently approximated by a sequence of notch arcs and straight lines.

In an assembling element which consists of three components and in which force or moment transmission takes place between a first component and the two further components and the three components are assembled such that they touch one another along a straight or curved contact line high pressure and tensile stress peaks arise in the components particularly in the region surrounding this contact line. In these instances a substantial equalization of the stress conditions can be achieved if clearance surfaces are formed along the common contact line which in the case of a curved contact line form a closed toroidal annular space or in the case of a straight contact line form a clearance channel of closed cross section which in its longitudinal extent surrounds the contact line.
A further equalization of the loads on the cooperating components at the contact surface and countercontact surface is achieved in that at least one of the contact surface or countercontact surface is provided with a camber. Depending on the load situation and the need the camber extends over the entire contact surface or countercontact surface or else only over a part region of one of these two contact surfaces.
Further designs advantageous for stress equalization of the cambers on the contact surface or the countercontact surface are achieved if the contour of the camber of the contact surface or of the countercontact surface is shaped in at least one cross section with an at least partially convex and continuously differentiatable curve.
A further possibility for favorably influencing the stress distribution is for the contour of the camber of the contact surface or countercontact surface to be formed in at least one cross section from at least two continuously differentiatable curve segments of which at least one curve segment is equipped with a convex curve profile the continuous differentiatability
being afforded at the transition point of adjacent curve segments. In a development of this embodiment the contour of the camber of the contact surface or countercontact surface is formed by three curve segments the middle curve segment being formed by a straight line and the adjacent curve segments being formed by convexly curved curves.
Likewise to achieve a uniform stress distribution it is expedient if the contour of the camber of the contact surface or countercontact surface is shaped in at least one cross section with a curve having a double-convex preferably symmetrical profile.
For the transmission of torques the first component forms with the contact surface and the second component with the countercontact surface a shrink assembly. Preferred applications for this are shaft/hub assemblies the first component being formed by a driveable shaft and the second component being formed by a torque-transmitting element such as a gearwheel friction wheel driving wheel or the like.
In a special application from rolling mill technology the first component is formed by a roll stand column with a blind hole bore arranged centrally in the crosshead and the second component is formed by a threaded nut with threaded spindle supported axially in the blind hole bore.
Employing the method according to the invention the present
invention comprises an assembling element consisting of at
least two components for transferring a pressure load from a
first component into at least one second component the first
component having a contact surface which bears against a
countercontact surface of the second component. This assembling
element is characterized in that the contact surface and the
countercontact surface overlap one another completely and
clearances or clearance surfaces start at all the margins of
the contact surface and of the countercontact surface.
Preferably at least one of the contact surface or
countercontact surface has a camber which extends over the
entire region of one of the contact surfaces or over at least a
part region of a contact surface. Cambers on both contact
surfaces of the two components said contact surfaces lying

opposite one another and being pressed against one another in the operating state are likewise possible.
The clearances on the contact surface and the countercontact surfaces are formed by clearance surfaces which at the tangent line with the contact surface and the countercontact surface are in each case approximately perpendicular with respect to this and in the case of spatially curved clearance surfaces form notches. The notches are provided in a special way with a contour in order to ensure stress peak minimization. Accordingly the clearances or clearance surfaces have a contour which is formed in one cross section approximately by a segment of an ellipse or by a three-center curve.
components and in which the components touch one another along a common contact line clearance surfaces are arranged which form a closed toroidal annular space or a clearance channel of closed cross section which in its longitudinal extent surrounds the contact line. The cross-sectional contour of the toroidal annular space or of the clearance channel of closed cross section is formed by curved lines.
The contour of the camber of the contact surface or
countercontact surface is formed in at least one cross section
by an at least partially convex and continuously
differentiatable curve. Alternatively the contour of the
camber of the contact surface or countercontact surface may be
formed in at least one cross section from at least two
continuously differentiatable curve segments of which at least
one curve segment has a convex curve profile the continuous
differentiatability being afforded at the transition point of
adjacent curve segments. Further the contour of the camber of
the contact surface or countercontact surface may also be
formed by three curve segments the middle curve segment being
formed by a straight line and the adjacent curve segments being
formed by convexly curved curves. A further possible embodiment
is for the contour of the camber of the contact surface or
countercontact surface to be formed in at least one cross
section by a curve having a double-convex preferably
symmetrical profile.
The proposed assembling element offers a multiplicity of possibilities for use in various fields of technology.
According to a preferred group of possibilities for use which relate to the basic element of a shaft/hub assembly the first component is formed by a driveable shaft which is coupled for example to a motor and the second component is formed by a
torque-transmitting element such as a gearwheel a friction wheel a driving wheel or the like. In this case the first component forms with the contact surface and the second component with the countercontact surface a shrink assembly.
A further preferred group of applications relates to the design of the contact surfaces of a pressure ram and of the counteracting supporting surface of a supporting element. A preferred concrete embodiment relates to the basic structure of a roll stand. In concrete terms the first component is formed by a roll stand column
with a blind hole bore arranged centrally in the crosshead and the second component is formed by a pressure nut with threaded spindle supported axially in the blind hole bore.
Further advantages and features of the present invention arise from the following description of unrestrictive exemplary embodiments reference being made to the accompanying figures in which:
fig. la shows a generalized illustration of an assembling
element with a defined contact surface and countercontact
surface fig. Ib shows the shaping according to the invention of the
contact surface and of the countercontact surface
according to fig. la fig. Ic shows a further shaping according to the invention of
the contact surface and of the countercontact surfaces
according to fig. 1 fig. 2a shows a first embodiment of a shaft/hub assembly in a
basic design fig. 2b shows the first embodiment of a shaft/hub assembly
according to fig. 2a with the shaping according to the
invention of the contact surface and of the countercontact
surface fig. 3a shows a second embodiment of a shaft/hub assembly in a
basic design fig. 3b shows the second embodiment of a shaft/hub assembly
according to fig. 3a with the shaping according to the
invention of the contact surface and of the countercontact
surface fig. 4a shows a third embodiment of a shaft/hub assembly in a
basic design
fig. 4b shows the third embodiment of a shaft/hub assembly according to fig. 4a with the shaping according to the
invention of the contact surface and of the countercontact
surface fig. 5a shows a fourth embodiment of an arrangement of a
pressure nut in a blind hole bore in a basic design fig. 5b shows the fourth embodiment of an arrangement of a
pressure nut in a blind hole bore according to fig. 5a
with the shaping according to the invention of the contact
surface and of the countercontact surface fig. 5c shows an enlargement of a detail of the edge formation
according to the invention of the contact surface and of
the countercontact surface fig. 6a shows a fifth embodiment with a shaft/hub assembly
having two helically toothed gearwheels in an arrangement
on a shaft in which they touch one another on the end
faces in a basic design
fig. 6b shows the fifth embodiment with a shaft/hub assembly having two helically toothed gearwheels in an arrangement on a shaft in which they touch one another on the end faces with the shaping according to the invention of the contact surface and of the countercontact surface
fig. 7a shows a sixth embodiment with three force-transmitting components touching one another
fig. 7b shows the sixth embodiment with the shaping according to the invention of the components in a sectional illustration along the line A-A in fig. 7a
fig. 7c shows the sixth embodiment with the shaping according to the invention of the components in a sectional illustration along the line B-B in fig. 7a
fig. 8a shows a seventh embodiment with an axially releasable assembly of a rolling mill drive
fig. 8b shows the seventh embodiment with the shaping according to the invention of the releasable assembly in a rolling mill drive in a partial section
fig. 8c shows an inner batten according to the seventh embodiment in the case of an alternating load direction.
In fig. la a first component 1 and a second component 2 of an assembling element not defined in any more detail are indicated as abstract parallelepipedal forms and the two components are illustrated at a vertical distance from one another. The supporting surface 3 of the first component 1 and the supporting surface 4 of the second component 2 said supporting surfaces overlapping one another in an overlap region 5 when viewed vertically are directed toward one another. This overlap region is defined as a contact surface 6 illustrated by thick lines on the first component 1 and a corresponding countercontact surface 7 on the second component 2 this contact surface and countercontact surface being pressed against one another under the action of a vertical force F in the subsequent operating state and therefore being
designed such that the stress distribution on the contact surfaces and in the region surrounding these contact surfaces takes place as uniformly as possible in the two cooperating components and in particular stress peaks in the marginal regions of the contact surfaces are avoided said stress peaks necessarily occurring in practice when components as illustrated in fig. la are pressed one onto the other without further structure measures.
As illustrated in fig. Ib a stress-optimized shaping of the contact surface 6 on the component 1 and of the countercontact surface 7 on the component 2 is achieved in a first step by the formation of clearances or clearance surfaces 8 by means
of which
the contact surface 6 and the countercontact surface 7 are delimited with respect to the adjoining regions of the supporting surface 3 and of the supporting surface 4. The clearance surfaces 8 start at the contact surfaces 6 7 approximately perpendicularly with respect to these and are transferred in groove form into the supporting surface 3 4. If the contact surfaces 3 4 end at one of the side walls 9 of one of the components there is no need for a special clearance surface to be formed. However as illustrated in fig. Ic the contact surface 6 and the countercontact surface 7 may be dimensioned smaller and in each case a peripheral clearance surface 8 may be incorporated on the contact surface and on the countercontact surface.
In a general consideration of a cooperating contact surface and countercontact surface which overlap one another a general marginal contact line is obtained and starting from this general marginal contact line the clearance surface commences with each surface which can be illustrated by straight lines and is formed by that perpendicular which arises from the Cartesian coordinate system when an axis lies along the marginal contact line and an axis lies in the contact surface.
The clearance surfaces of the cooperating components are determined by means of up-to-date optimization software and are expediently approximated in manufacturing terms by means of a sequence of three-centered curves and straight lines. The design of the clearance surfaces in this case takes place individually for each component and takes into account the local stress conditions.
The countercontact surface 7 illustrated in fig. Ib is designed with a camber 24 in the X-direction and in the Y-direction starting from a planar middle region so as in each case to have a camber descending towards the margins of the
countercontact surface and is indicated by thin lines. This measure too contributes substantially to reducing stress peaks in the marginal zones.
Figures 2a to 4b and 6a 6b illustrate advantageous embodiments of the shaping according to the invention of a shaft/hub assembly the shaft constituting the first component 1 and the hub the second component 2 of the assembling element. The shaft and hub are assembled by means of a shrink assembly and are suitable especially for the transmission of torques. The shaping according to the invention of the contact and countercontact surfaces is to be illustrated in more detail by means of this in no way restrictive choice of possible assemblies.
In the design illustration according to fig. 2a a component 2 formed by a hub is shrunk on a component 1 constituting a shaft the hub being connected only over a part length of its longitudinal extent to the shaft. The cylindrical inner wall of the hub forms the supporting surface 3 of the component 2 and the cylindrical surface area of the shaft forms the supporting surface 4 of the component 1. In the overlap region of the two supporting surfaces 3 4 the cooperating contact surfaces 6 of the component 1 and countercontact surface 7 of the component 2 are defined and these defined surfaces must overlap one another entirely.
Fig. 2b illustrates the shaping of clearance surfaces starting
from the margins of the contact surface 6 and countercontact
surface 7. According to the invention the clearance surfaces
starting from the margins of the two contact surfaces are
oriented perpendicularly with respect to these and are led back
in the form of an arc to the respective supporting surface 2
3. Accordingly a clearance surface 8a starting from the edge
10 is produced as a recess into the shaft (component 1) and a
clearance surface 8b starting from the edge 11 is produced as
a recess into the hub (component 2) . The vertical end faces
adjoining the contact surface and countercontact surface of
the first and the second component require no particular
clearance at the contact surface and countercontact surface.
The design illustration according to fig. 3a shows a shaft/hub assembly in which a cylindrical component 2 (hub) is shrunk onto a cylindrical component 1 (shaft) and the component 2 is fastened at a shaft shoulder in alignment with the end wall on the shaft portion having the larger diameter. It is necessary here to arrange a clearance surface 8a in the manner of a recess into the component 1 adjacently to the defined contact surface 6 of the component 1. End faces 12 13 oriented perpendicularly with respect to the contact surface 6 and
margin of these contact surfaces so that a special clearance is not necessary here. However a rounding-out is provided on the shaft shoulder as corresponds to conventional design practice.
The design illustration according to fig. 4a again shows a shaft/hub assembly with a stepped shaft which forms the component 1 and with a hub which forms the component 2 the hub being shrunk on the shaft journal having the smaller diameter and bearing against the end face 14 of the shaft. This embodiment requires a special fixing of the contact surface and countercontact surface in the region of the shaft shoulder since by the hub bearing against the end face 14 of the shaft
-lithe stress conditions in this region are disturbed to a particular extent. This is illustrated in fig. 4b. In order to provide space for arranging the clearance surfaces in the shoulder region of the shaft the contact surface 6 and the countercontact surface 7 commence only at a distance a from the end face 14. Starting from the margins of the contact surface 6 of the shaft toroidal clearance surfaces 8a 8b are formed by a turned groove or by a recess into the shaft the clearance surface 8a merging arcuately into the end face 14. The clearance surface 8c which starts from the countercontact surface 7 is of arcuate design and ends on the end face 15 of the hub. Overall a toroidal free space in the critical edge region is provided.
A further exemplary embodiment from rolling mill technology
illustrated in a design illustration in fig. 5a relates to a
roll stand in particular to the contact zone of the crosshead
of a roll stand column 16 and of a pressure nut 17 which is
supported in a blind hole bore 18 of the roll stand column. In
the contact zone of the blind hole bore and pressure nut the
rolling force is introduced into the roll stand column via a
threaded spindle and the pressure nut. During load
transmission normally high pressure and tensile stress zones
occur locally next to one another. Owing to an optimal shaping
of the contact region both zones can achieve a largely uniform
comparative stress at a low level and consequently ensure the
highest possible reliability against permanent breakage. In a
conventional structure configuration as illustrated in fig.
5a considerable comparative stress peaks causing permanent
load damage arise in the regions surrounding the edges 19 and
20 both in the pressure nut 17 and in the crosshead of the roll
stand column 16 (in the bottom region of the blind hole bore).
As illustrated enlarged in fig. 5b and 5c a contact surface 6 and a countercontact surface 7 which offer sufficient space
for the formation of clearance surfaces 8a 8b 8c are defined on the pressure nut 17 and the cross head of the roll stand column 16 on the opposite supporting surfaces 3 4. The essentially rotationally symmetrical pressure nut 17 is equipped in the contact region of a blind hole bore with a peripheral toroidal clearance surface 8a which starting from the end countercontact surface 7 runs commencing perpendicularly with respect to the latter arcuately to the side wall 21. The contour of this clearance surface 8a corresponds to a rounding-out radius r. A clearance surface 8c is likewise formed on the pressure nut in the region of the through bore of the roll stand column.
Since the contact surface 6 and the countercontact surface 7 overlap one another entirely the clearance surface 8b in the crosshead starts on the contact surface 6 so as to directly adjoin the clearance surface 8a (edge 22). The clearance surface 8b extends at least along the edge with the contact surface 6 perpendicularly with respect to the latter and runs arcuately as far as the edge 23 where it coincides again with the clearance surface 8a. The clearance surface 8b is formed by a segment of a three-centered curve which has a radius of curvature ri in a first region and a radius of curvature r2 in a second region. By virtue of this special shaping the peak values of the comparative stresses particularly the tensile stress peaks are greatly reduced and equalized in the optimization range in relation to an embodiment according to fig. 5a.The design illustration according to fig. 6a shows a shaft
forming the component 1 with a supporting surface 3 and with
two radially shrunk-on gearwheels with supporting surfaces 4a
4b which form the components 2a 2b the two gearwheels being
arranged so as to lie closely against one another and the end
faces. In this embodiment there is 3-body contact in which
the three components 1 2a 2b meet with their supporting
surfaces 3 4a 4b along a contact line L and the stress
conditions in this region are particularly disturbed due to the
mutual support of the individual components. Singular stress
concentrations at the hub margin of the joint surfaces arise.
It is therefore particularly important starting from the
contact line L which forms a singularity to define the contact
surfaces 6a 6b on the component 1 and the countercontact
surfaces 7a 7b on the components 2a 2b and also the necessary
clearance surfaces on the three components. These clearances
are illustrated in more detail in fig. 6b. Starting from the
edges 10 and 11 of the contact surfaces 6a and 7a and 6b and 7b
which overlap one another in pairs clearance surfaces 8a 8b

8c 8d are formed which are oriented at the edges 10 11 perpendicularly with respect to the contact surfaces and form a closed toroidal annular space 16 and which include the singularity L. The clearances 8e 8f on the contact line of the two outer end faces of the gearwheel-forming components 2a 2b with the shaft are designed similarly to the exemplary embodiment according to figures 2b 3b or 4b.
The design illustration according to fig. 7a shows the cooperation of three components 1 2a 2b by means of a sixth embodiment two further components 2a 2b being supported with their supporting surfaces 4a 4b on a supporting surface 3 of a component 1. The components 2a 2b touch one another in each case with a further side surface.The force action F takes place perpendicularly with respect to the supporting surfaces of the components. In this embodiment there is likewise 3-body contact in which the three components meet with their supporting surfaces along a contact line L and the stress conditions in this region are particularly disturbed due to the mutual support of the individual components. It is therefore particularly important starting from the contact line L which forms a singularity to define the contact surfaces 6a 6b on the component 1 and the countercontact surfaces la 7b on the components 2a 2b and also the necessary clearance surfaces on the three components. These clearances are partially illustrated in more detail in figures 7b and 7c fig. 7b showing a sectional illustration along the sectional line A-A in fig. 7a and fig. 7c showing a sectional illustration along the sectional line B-B in fig. 7a. Starting from the edges 10 11 (fig. 7b) of the contact surfaces 6a and 7a and 6b and 7b overlapping one another in pairs clearance surfaces 8a 8b 8c 8d are formed which are oriented at the edges 10 11 perpendicularly with respect to the contact surfaces and which form a clearance channel 31 of closed cross-section and include the singularity L. In addition starting from the edges 25 26 27 28 29 30 clearance surfaces are arranged which form a closed groove-shaped clearance in the component 1 the clearance surfaces 8e 8f 8g 8h being illustrated. All clearance surfaces not illustrated are designed similarly.The design drawing according to fig. 8a shows by the example of a rolling mill drive for a working roll in cross section a drive shaft with a flat journal 41 which projects into a central recess of a cylindrical coupler 42 which is itself equipped with two inner battens 43 44. A play s for the easy axial assembling and separation of the components of the drive system is provided between the cheeks 45 46 of the flat journal 41 and the supporting surfaces 47 48 of the inner
battens. When the drive moment is applied and under load a tilting of the flat journal occurs between the inner battens so that linear or point contact of the longitudinal edges 50 51 of the flat journal on the supporting surfaces 47 48 of the inner battens arises and consequently high surface pressure and stress peaks occur in this contact region of the components. The play s prevents the cheeks 45 46 of the flat journal from bearing over a large area against the supporting surfaces 47 48 of the two inner battens.
In order to achieve an optimization of the stress conditions with the effect of equalizing the surface pressure in the assembling element it is necessary as illustrated in fig. 8b to coordinate the contact surface 52 on the cylindrical coupler 42 and the opposite countercontact surface 53 on the inner batten 43 with one another so thata mutual overlap of these surfaces is achieved and to define clearance surfaces 8a 8b with an optimized contour starting from the edge 10. This takes place as already described in the preceding exemplary embodiments. The supporting surface 47 of the inner batten 43 is to be arranged with an inclination at an angle e to the vertical which compensates the predetermined play s between the inner batten 43 and the cheek 45 in the nonloaded state of the assembling element and ensures that the cheek bears over a large area against the supporting surface of the inner batten. Further as in the preceding exemplary embodiments the supporting surface 47 of the inner batten 43 is to be coordinated with the surface of the cheek 45 with the effect of a mutual overlap and a corresponding clearance surface 8c with an optimized contour starting from the edge 11 is to be formed.
In the case of a changing direction of rotation and therefore a changing load direction the inner battens are to be designed according to fig. 8c.In the configuration of an asembly according to the invention of components it is not important in the cooperation of two components or of three components whether the contact surfaces and the countercontact surfaces are formed by planar surfaces or by spatially curved surfaces (preferably cylindrical surfaces) nor is the geometric form of these surfaces (rectangular square round annular or the like) important but solely the complete overlap and the configuration of the clearance surfaces starting from the edges of the contact surface and countercontact surface.In all the embodiments described by way of example an additional equalization of the surface pressure and therefore of the comparative stress conditions can be achieved via thecontact surface and countercontact surface by a cambered design of at least one of the contact surface or countercontact surface.

Patent Claims:
1. A method for shaping a contact surface (6, 6a, 6b) and a
countercontact surface (7, la, 7b) of an assembling
element which consists of at least two components for
transferring a pressure load from a first component (1)
into at least one second component (2, 2a, 2b) ,
characterized in that an overlap region (5) of a geometric
supporting surface (3) of a first component (1) and of a
geometric supporting surface (4, 4a, 4b) of a second
component (2) is defined as a contact surface (6, 6a, 6b)
of the first component and as a countercontact surface (7,
7a, 7b) of the second component in terms of their
geometric extent, the contact surface and the
countercontact surface overlapping one another completely,
and in that clearances are formed, starting from the
limits of the defined contact surface and countercontact
surface, those regions of the supporting surfaces of the
first and of the second component which project beyond the
contact surface and the countercontact surface being
spatially offset from the contact surface and the
countercontact surface.
2. The method as claimed in claim 1, characterized in that
the clearances on the contact surface and the
countercontact surface are formed by clearance surfaces
(8, 8a, 8b, 8c, 8d, 8e, 8f, 8g, 8h) which at the tangent
line with the contact surface and the countercontact
surface run in each case approximately perpendicularly
with respect to this and with respect to the remaining
supporting surface form a notch.
3. The method as claimed in claim 1 or 2, characterized in
that the clearances are designed with a contour which in
cross section form approximately a segment of an ellipse.

4. The method as claimed in claim 1 or 2, characterized in
that the clearances are designed with a contour which in
cross section form approximately a three-center curve.
5. The method as claimed in one of the preceding claims,
characterized in that, in the case of an assembling
element consisting of three components (1, 2a, 2b) ,
clearance surfaces (8a, 8b, 8c, 8d)
are formed along a common contact line (L) , which form a closed toroidal annular space (16) or a clearance channel (31) of closed cross section which in its longitudinal extent surrounds the contact line (L) .
6. The method as claimed in one of the preceding claims,
characterized in that at least one of the contact surface
or countercontact surface is provided with a camber (24).
7. The method as claimed in claim 6, characterized in that
the contour of the camber (24) of the contact surface or
of the countercontact surface is shaped in at least one
cross section with an at least partially convex and
continuously differentiatable curve.
8. The method as claimed in claim 6 or 7, characterized in
that the contour of the camber (24) of the contact surface
or countercontact surface is formed in at least one cross
section from at least two continuously differentiatable
curve segments, of which at least one curve segment has a
convex curve profile, the continuous differentiatability
being afforded at the transition point of adjacent curve
segments.
9. The method as claimed in claim 6 or 7, characterized in
that the contour of the camber (24) of the contact surface
or countercontact surface is formed by three curve
segments, the middle curve segment being formed by a
straight line and the adjacent curve segments being formed
by convexly curved curves.
10. The method as claimed in claim 6 or 7, characterized in
that the contour of the camber (24) of the contact surface
or countercontact surface is shaped in at least one cross
section with a curve having a double-convex, preferably symmetrical profile.
11. The method as claimed in one of the preceding claims, characterized in that the first component forms with the contact surface and the second component with the countercontact surface a shrink assembly.
12. The method as claimed in claim 11, characterized in that
the first component is formed by a driveable shaft and the
second component is formed by a torque-transmitting
element, such as a hub, gearwheel, friction wheel or
driving wheel.
13. The method as claimed in one of the preceding claims 1 to
10, characterized in that the first component is formed by
a roll stand column (16) with a blind hole bore arranged
centrally in the crosshead, and the second component is
formed by a pressure nut (17) with threaded spindle
supported axially in the blind hole bore.
14. An assembling element, consisting of at least two
components for transferring a pressure load from a first
component (1) into at least one second component (2), the
first component having a contact surface (6, 6a, 6b) which
bears against a countercontact surface (7, 7a, 7b) of the
second component, produced by a method as claimed in one
of claims 1 to 12, characterized in that the contact
surface and countercontact surface overlap one another
completely, and in that clearances (8, 8a, 8b, 8c, 8d, 8e,
8f, 8g, 8h) start at all the margins of the contact
surface and of the countercontact surface.
15. The assembling element as claimed in claim 14, characterized in that the clearances on the contact surface and the countercontact surfaces are formed by clearance surfaces (8, 8a, 8b, 8c, 8d, 8e, 8f) which at the tangent line with the contact surface and the countercontact surface are in each case approximately perpendicular with respect to this and in the case of spatially curved clearance surfaces form notches.
16. The assembling element as claimed in claim 14 or 15,
characterized in that the clearance surface has a contour
which is formed in one cross section approximately by a
segment of an ellipse.
17. The assembling element as claimed in claim 14 or 15,
characterized in that the clearance surface has a contour
which is formed in one cross section approximately by a
three-center curve.
18. The assembling element as claimed in one of claims 14 to
17, characterized in that, in the case of an assembling
element consisting of three components (1, 2a, 2b),

clearance surfaces (8a, 8b, 8c, 8d) are arranged along a common contact line (L) , which form a closed toroidal annular space (16) or a clearance channel (31) of closed cross section which in its longitudinal extent surrounds the contact line (L).
19. The assembling element as claimed in one of claims 14 to
18, characterized in that at least one of the contact
surface and countercontact surface has a camber (24).
20. The assembling element as claimed in claim 19,
characterized in that the contour of the camber of the
contact surface or countercontact surface is formed in at
least one cross section by an at least partially convex
and continuously differentiatable curve.
21. The assembling element as claimed in claim 19 or 20,
characterized in that the contour of the camber of the
contact surface or countercontact surface is formed in at
least one cross section from at least two continuously
differentiatable curve segments, of which at least one
curve segment has a convex curve profile, the continuous
differentiatability being afforded at the transition point
of adjacent curve segments.
22. The assembling element as claimed in claim 19 or 20,
characterized in that the contour of the camber of the
contact surface or countercontact surface is formed by
three curve segments, the middle curve segment being
formed by a straight line and the adjacent curve segments
being formed by convexly curved curves.
23. The assembling element as claimed in claim 19 or 20,
characterized in that the contour of the camber of the
contact surface or countercontact surface is formed in at

least one cross section by a curve having a double-convex, preferably symmetrical profile.
24. The assembling element as claimed in one of the preceding claims 14 to 23, characterized in that the first component forms with the contact surface and the second component with the countercontact surface a shrink assembly.
25. The assembling element as claimed in claim 24, characterized in that the first component is formed by a driveable shaft and the second component is formed by a torque-transmitting element, such as a hub, gearwheel, friction wheel, driving wheel, etc.
26. The assembling element as claimed in one of the preceding claims 14 to 23, characterized in that the first component is formed by a roll stand column (16) with a blind hole bore (18) arranged centrally in the crosshead, and the second component is formed by a pressure nut (17) with threaded spindle supported axially in the blind hole bore.

Documents:

1966-delnp-2007-Abstract-(31-07-2014).pdf

1966-delnp-2007-abstract.pdf

1966-delnp-2007-Claims-(31-07-2014).pdf

1966-delnp-2007-claims.pdf

1966-delnp-2007-Correspondance Others-(19-12-2014).pdf

1966-delnp-2007-Correspondence Others-(10-08-2011).pdf

1966-delnp-2007-Correspondence Others-(12-05-2014).pdf

1966-delnp-2007-Correspondence Others-(31-07-2014).pdf

1966-delnp-2007-correspondence-others-1.pdf

1966-delnp-2007-correspondence-others.pdf

1966-delnp-2007-Description (Complete)-(31-07-2014).pdf

1966-delnp-2007-description (complete).pdf

1966-delnp-2007-Drawings-(31-07-2014).pdf

1966-delnp-2007-drawings.pdf

1966-delnp-2007-form-1.pdf

1966-delnp-2007-form-18.pdf

1966-delnp-2007-Form-2-(31-07-2014).pdf

1966-delnp-2007-form-2.pdf

1966-delnp-2007-Form-3-(12-05-2014).pdf

1966-delnp-2007-form-3.pdf

1966-delnp-2007-form-5.pdf

1966-delnp-2007-GPA-(10-08-2011).pdf

1966-delnp-2007-GPA-(31-07-2014).pdf

1966-delnp-2007-pct-210.pdf

1966-delnp-2007-pct-304.pdf

1966-delnp-2007-pct-308.pdf

abstract.jpg

Petition_1966-DELNP-2007.pdf

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Patent Number

265080

Indian Patent Application Number

1966/DELNP/2007

PG Journal Number

07/2015

Publication Date

13-Feb-2015

Grant Date

05-Feb-2015

Date of Filing

14-Mar-2007

Name of Patentee

SIEMENS VAI METALS TECHNOLOGIES GmbH

Applicant Address

TURMSTRASSE 44, 4031 LINZ, AUSTRIA

Inventors:

#	Inventor's Name	Inventor's Address
1	RUDOLF GRUBER	TURKSTETTEN 60, A-4021 GRAMASTETTEN, AUSTRIA
2	KARL MAYRHOFER	OBENBERG 36, A-4312 RIED/RIEDMARK, AUSTRIA

PCT International Classification Number

B23P 11/00

PCT International Application Number

PCT/EP2005/009081

PCT International Filing date

2005-08-23

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	A1534/2004	2004-09-13	Austria