Note: Descriptions are shown in the official language in which they were submitted.
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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
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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;
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"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
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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
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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.
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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.
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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
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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.
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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
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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.
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In an assembling element which consists of three 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
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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
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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.
In accordance with the invention, there is provided 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, wherein 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.
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:
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fig. la shows a generalized illustration of an assembling
element with a defined contact surface and countercontact
surface,
fig. lb shows the shaping according to the invention of the
contact surface and of the countercontact surface
according to fig. la,
fig. lc 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
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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,
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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
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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. lb, 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
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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. lc, 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. lb 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 caniber descending towards the margins of the
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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.
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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
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countercontact surface 7 adjoin the opposite 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,
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the 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
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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.
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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 r1 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,
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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.
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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 7a, 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
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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 that
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a 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 assembly 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 the
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contact surface and countercontact surface by a cambered design
of at least one of the contact surface or countercontact
surface.
