U.S. patent application number 11/277781 was filed with the patent office on 2006-11-30 for machine housing.
Invention is credited to Joachim Krautzig, Mladen Matan.
Application Number | 20060269393 11/277781 |
Document ID | / |
Family ID | 36121305 |
Filed Date | 2006-11-30 |
United States Patent
Application |
20060269393 |
Kind Code |
A1 |
Krautzig; Joachim ; et
al. |
November 30, 2006 |
Machine housing
Abstract
A housing (1) for a machine, in particular a turbomachine,
includes a first housing shell (2) which bears against a second
housing shell (3) along a parting plane (4). In order to avoid an
asymmetric deformation of the housing (1) when the machine is in
operation, in the region of the parting plane (4) at least one
bridge (6) is formed, by which the two housing shells (2, 3) are
fastened to one another. In this case, the at least one bridge (6)
extends perpendicularly with respect to the parting plane (4). The
bridge (6) is firmly connected on one side of the parting plane
(4), in a first bridge portion (7), to the first housing shell (2)
and on the other side of the parting plane (4), in a second bridge
portion (8), to the second housing shell (3).
Inventors: |
Krautzig; Joachim; (Widen,
CH) ; Matan; Mladen; (Karlovac, HR) |
Correspondence
Address: |
CERMAK & KENEALY LLP
515 E. BRADDOCK RD
SUITE B
ALEXANDRIA
VA
22314
US
|
Family ID: |
36121305 |
Appl. No.: |
11/277781 |
Filed: |
March 29, 2006 |
Current U.S.
Class: |
415/55.1 |
Current CPC
Class: |
F01D 25/243
20130101 |
Class at
Publication: |
415/055.1 |
International
Class: |
F04D 5/00 20060101
F04D005/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 31, 2005 |
DE |
10 2005 015 150.7 |
Claims
1. A housing for a machine, the housing comprising: a first housing
shell and a second housing shell, the first housing shell bearing
against the second housing shell along a parting plane at least one
bridge in the region of the parting plane, the at least one bridge
extending transversely with respect to the parting plane and
including a first bridge portion and a second bridge portion, the
first bridge portion firmly connected on one side of the parting
plane to the first housing shell, and the second bridge portion
firmly connected on the other side of the parting plane to the
second housing shell.
2. The housing as claimed in claim 1, further comprising: at least
one screw attaching at least one of the first and second bridge
portions to an associated housing shell; or the firm connection
between the first bridge portion, the second bridge portion, or
both, to an associated housing shell being configured and arranged
for transmission of moments of flexion in the circumferential
direction; or one of the first and second bridge portions being
integral with an associated housing shell; or a positive connection
connecting at least one of the first and second bridge portions to
an associated housing shell; or the housing comprising a
cylindrical outer contour, and at least one of the first and second
bridge portions extending within said cylindrical outer contour; or
a clearance formed on one of the housing shells, at least one of
the first and second bridge portions extending within said
clearance; or combinations thereof.
3. The housing as claimed in claim 1, further comprising: at least
one contact face formed on at least one of the first and second
bridge portions, and at least one contact counterface formed on one
of said first and second housing shells, said at least one bridge
portion contact face bearing against said at least one contact
counterface.
4. The housing as claimed in claim 3, wherein: the at least one
bridge is connected to the first and second housing shells so that
said at least one contact face is pressed against said at least one
contact counterface; or the at least one contact face, the at least
one contact counterface, or both, comprises a surface with an
increased coefficient of friction; or the at least one contact face
and the at least one contact counterface comprise form-fitting
contours transmitting shear forces and complementary to one
another; or the at least one contact face and the at least one
contact counterface extend in a plane which stands, on the parting
plane; or the at least one contact face and the at least one
contact counterface extend along a curve which is concave toward
the inside of the housing; or combinations thereof.
5. The housing as claimed in claim 1, wherein the two housing
shells are fastened to one another in the region of the parting
plane solely via the at least one bridge.
6. The housing as claimed in claim 1, further comprising: at least
one screw additionally and directly attaching the first and second
housing shells to one another in the region of the parting
plane.
7. The housing as claimed in claim 6, wherein said at least one
screw passes through the parting plane.
8. The housing as claimed in claim 1, wherein the housing is
axially symmetrical, cylindrically symmetrical, rotationally
symmetrical, or combinations thereof; or wherein the housing is
configured and arranged to be loaded internally or externally with
excess pressure, thermally, or both, when in operation; or
both.
9. The housing as claimed in claim 1, wherein at least one of the
at least one bridge comprises a plate, having a longitudinal
dimension measured in the parting plane and in the longitudinal
direction of the housing greater than a dimension measured
transversely with respect to the parting plane; or wherein at least
one of the at least one bridge comprises a bar, having a
longitudinal dimension measured in the parting plane and in the
longitudinal direction of the housing smaller than a dimension
measured transversely with respect to the parting plane; or
both.
10. The housing as claimed in claim 1, wherein the first and second
housing shells, in the region of the parting plane, and the at
least one bridge are configured and arranged to form an at least
approximately constant mass distribution over the entire housing
circumference.
11. The housing as claimed in claim 1, wherein the machine
comprises a turbomachine.
12. The housing as claimed in claim 4, wherein the at lest one
contact face and the at least one contact counterface extend in a
plane which stands perpendicularly on the parting plane.
13. The housing as claimed in claim 4, wherein the at least one
contact face and the at least one contact counterface extend along
a curve which is concave toward the inside of the housing and which
extends coaxially with respect to a curve of the housing shells in
the region of the parting plane.
Description
[0001] This application claims priority under 35 U.S.C. .sctn. 119
to German application number 10 2005 015 150.7, filed 31 Mar. 2005,
the entirety of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a housing for a machine, in
particular virtually rotationally symmetrical housings, for example
for a turbomachine, with a first housing shell which is connected
to a second housing shell along a parting plane passing mostly
through the machine axis or axes.
[0004] 2. Brief Description of the Related Art
[0005] In a housing of this type, in the region of the parting
plane, at least one flange is formed, by means of which the two
housing shells are fastened to one another. Conventionally, this
flange extends in the parting plane and there forms a housing
widening which extends radially with respect to a longitudinal
direction of the housing and which usually reaches over the entire
axial length or circumference of the housing. The two housing
shells are screwed directly to one another in the region of the
flange, the respective screw connection passing through the parting
plane preferably perpendicularly.
[0006] The housing shells thus conventionally possess contact faces
extending in the parting plane, which lie against one another along
the parting plane and are pressed against one another within the
respective flange by means of the respective screw connection.
[0007] Furthermore, a housing of this type, at least in a
turbomachine, such as, for example, a turbine or a compressor, may
have a rotationally symmetrical or virtually rotationally
symmetrical form. The radially projecting flanges cause a
disturbance in such a housing in two respects: on the one hand, the
rigidity of the flange region in respect of a moment of flexion in
the circumferential direction, for example a thermal moment as a
result of a radial temperature gradient over the wall, is locally
markedly different from the rest of the circumference, and, on the
other hand, the additional masses and the radial extent of the
flanges lead to a changed temperature behavior of the housing in
the region of the flange. Both disturbances have an adverse effect
on the deformation behavior of the housing, in that, even when the
pressure and/or thermal load is constant in the circumferential
direction, locally different curvatures and distortions occur. As a
result, during operation, a rotationally symmetrical housing
acquires a cross section which is no longer circular.
[0008] In order to keep the circumferential rigidity constant, the
flanges must have a width of approximately 2-3 times the wall
thickness. What opposes this is that they should ideally not
project beyond the (rotational) contour of the remaining housing
for reasons of as uniform a thermal behavior as possible and a
reduction in overall size. For these contradictory requirements, on
the one hand, sufficient flexural rigidity in the circumferential
direction and, on the other hand, a low radial extent, a
satisfactory compromise has been difficult to find with the design
principles known hitherto.
[0009] In this regard, the various known solutions of the prior art
for alternative principles for the connection of housing flanges
also do not constitute a solution which is satisfactory in this
respect, because these are mainly aimed at increasing the closing
forces, sometimes at the expense of lower circumferential rigidity
and without regard to the necessary installation space.
[0010] Thus, DE 853 451 describes clamps which generate markedly
higher closing forces from relatively low horizontal tension bolt
forces via wedge or toggle lever mechanisms. So that these closing
forces can be applied without excessively high circumferential
moments as a result of wall tension and the distance of the clamps
from the wall center line, the flanges must be kept particularly
narrow, thus further reducing their circumferential rigidity, even
though the necessary radial installation space is very large.
[0011] An alternative proposal with a similar aim is the subject of
Swiss publication CH 319 355, in which the closing forces are
generated from lower bolt tension forces via a lever mechanism. In
contrast to the previous solution proposal, the circumferential
rigidity is likewise increased on account of the large radial width
of the flange, but at the expense of a high space requirement with
correspondingly problematic thermal behavior.
[0012] U.S. Pat. No. 2,457,073 illustrates a combination of the two
principles discussed above: a clamp with a lever mechanism acts on
a narrow nose in a cylindrical wall of virtually constant
thickness. Consequently, transient thermal processes should cause
highly uniform temperature distributions, but the flexural rigidity
of the parting plane is minimal.
[0013] U.S. Pat. No. 2,276,603 likewise proposes clamps with a
wedge mechanism for generating the closing forces, similar to the
abovementioned DE 853 451. However, because of the small vertical
bearing faces remaining between the clamp and the housing half, the
circumferential stiffening is only minor. The aim is obviously
solely to achieve greater closing forces.
[0014] Finally, U.S. Pat. No. 2,169,092 proposes use of double
T-shaped shrunk-in ties instead of bolts.
[0015] In may be stated, overall, that the solutions presented here
are directed primarily at sealing of the housing shells and at
generating high closing forces, but ignore the problems of
circumferential rigidity and mass distribution and the risk of
asymmetric deformation.
[0016] This has the unavoidable consequence that a high flexural
rigidity in the circumferential direction, with as uniform a mass
distribution as possible in the flange region, to ensure the
highest possible rotational symmetry, along with high mechanical
and thermal load-bearing capacity, is not achieved according to
these solutions.
[0017] Precisely where turbomachines are concerned, however, an
asymmetric deformation of the housing presents problems, since, as
a rule, the housing serves for carrying guide blades and sealing
zones for moving blades. An asymmetric deformation of the housing
disturbs the throughflow of the turbomachine. In particular, radial
gaps may be formed or enlarged between the moving blades and the
housing-side sealing zones and between the guide blades and
rotor-side sealing zones, thus causing the flow to pass around the
blades at their tip. The efficiency of a turbomachine is
significantly reduced, however, when the high-energy flow flows
around the blades at their tip and therefore does not transmit any
work to the respective blade.
SUMMARY OF THE INVENTION
[0018] This is where the invention comes in. One aspect of the
present invention is concerned with the problem of specifying, for
a housing of the type initially mentioned, an improved embodiment
which, in particular, significantly improves the dimensional
stability of the housing, in that the circumferential rigidity,
even in the region of the parting plane, is virtually constantly
equal to that of the rest of the housing circumference, while at
the same time the radial extent in the region of the parting plane
can be largely adapted to the remaining rotational contour of the
housing.
[0019] Another aspect of the present invention includes attaching,
instead of the respective, in particular horizontal flanges, at
least one bridge which extends perpendicularly with respect to the
parting plane and which is connected firmly, and rigidly in terms
of moment of deflection in the circumferential direction, on both
sides of the parting plane, in each case in a corresponding bridge
portion, both to one housing shell and to the other shell. A bridge
of this type forms, transversely with respect to the parting plane,
a tie which connects the two housing halves in the parting plane
firmly to one another such that they bear against one another. In
this case, the local flexural rigidity achievable at the parting
plane with the aid of the bridge can be made virtually ideally
equal to the rest of the circumference. In addition, if necessary,
by appropriate dimensioning and/or additional structural elements,
the tensile strength of the bridge can be many times higher than in
the case of a conventional screw connection which passes through
the flange perpendicularly with respect to the parting plane. A
particularly advantageous feature, however, is the connection in
the circumferential direction which is rigid in terms of moment of
deflection, at the same time with a reduction in the radial extent
in the parting plane.
[0020] The bridge may be screwed or otherwise connected on one of
the bridge portions or on both bridge portions to the housing half
associated in each case. With the aid of a screw connection of this
type, a suitable selection of the screwing points in terms of
positioning and/or number and/or dimensioning, particularly high
flexural rigidity and, if necessary, also strength can be produced
for the respective connection between the respective housing shell
and the respective bridge portion.
[0021] It is likewise basically possible to integrate one of the
two bridge portions into the associated housing shell, that is to
say the bridge then forms an integral part of the respective
housing shell. This results particularly simply in a firm
connection between the housing shell and the bridge formed
integrally on it or in one piece or in one part with it, and only
one side of the bridge is connected releasably to the other housing
shell.
[0022] Additionally or alternatively, at least one of the bridge
portions may be connected to the associated housing shell via a
positive connection. Suitable positive connections are, for
example, a dovetail coupling, a hammerhead coupling or a clamp
coupling. As a result of form fit, particularly high moments and
forces can be transmitted directly between the bridge and the
respective housing shell, while, basically, screws for the
transmission of pairs of forces of circumferential moments and/or
shear forces between the bridge and the respective housing shell
may be dispensed with.
[0023] Further important features and advantages of the housing
according to the invention may be gathered from the drawings and
from the associated figure description with reference to the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Preferred exemplary embodiments of the invention are
illustrated in the drawings and are explained in more detail in the
following description, the same reference symbols referring to
identical or similar or functionally identical components. In the
drawings, in each case diagrammatically,
[0025] FIG. 1 to 9 show in each case a cross section through a
housing according to the invention in the region of the parting
plane of the housing shells in different embodiments.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0026] According to FIG. 1 to 9, a housing 1 according to the
invention includes a first housing shell 2 and a second housing
shell 3. The two housing shells 2, 3 bear against one another along
a parting plane 4. The housing 1 is in this case the housing 1 of a
machine, preferably a turbomachine, such as, for example, a
turbine, a gas turbine, a steam turbine or a compressor. In the
exemplary embodiments shown here, the housing 1 has a rotationally
symmetrical form. However, this is not obligatory. It is likewise
possible for this invention to be applied to other housing forms or
machine types. When the respective machine is in operation, the
housing 1 may be loaded internally or externally with an excess
pressure. The housing 1 may likewise be loaded internally or
externally in a thermal manner. The housing shells 2, 3 are exposed
correspondingly to high deformation forces. In order to fasten the
two housing shells 2, 3 to one another, at least one bridge 6 is
provided in the region of the parting plane 4. This bridge 6 is
likewise exposed to particularly high loads on account of the
abovementioned high loads of the housing 1. The bridge 6 may
basically extend in the axial direction over the entire length of
the housing 1. It is likewise possible for a plurality of such
bridges 6 to be arranged one behind the other in the axial
direction of the housing 1. Furthermore, it is clear that the
housing 1 may likewise have at least one such bridge 6 in the
diametrically opposite parting plane 4.
[0027] So that the bridge 6 does not lead to an asymmetric
deformation of the housing 1 on account of the loads occurring, it
should have essentially the same strength and rigidity values and,
in particular, the same thermal properties (mass, wall thickness,
radial extent) as the remaining region of the housing shells 2,
3.
[0028] This bridge 6 extends perpendicularly with respect to the
parting plane 4 and is arranged such that it passes through the
parting plane 4. The bridge 6 correspondingly has a first bridge
portion 7 which is located on the same side of the parting plane 4
as the first housing shell 2. Furthermore, the bridge 6 has a
second bridge portion 8 which is located on the outer side of the
parting plane 4 in the same way as the second housing shell 3. The
first bridge portion 7 is connected firmly to the first housing
shell 2. The second bridge portion 8 is connected firmly to the
second housing shell 3.
[0029] In the embodiment according to FIG. 1, the two bridge
portions 7 and 8 are screwed to the associated housing shells 2, 3.
Corresponding screw connections 9 are indicated by dashes and dots
in FIG. 1. The number and/or positioning and/or dimensioning of the
screw connections 9 are selected as a function of the forces and
moments to be transmitted.
[0030] So that particularly high moments and even forces can be
transmitted between the bridge 6 and the housing shells 2, 3, the
respective bridge portion 7, 8 has provided on it an associated
contact face, to be precise a first contact face 10 on the first
bridge portion 7 and a second contact face 11 on the second bridge
portion 8. Complementarily to this, the first housing shell 2 has a
first contact counterface 12, while the second housing shell 3
possesses a second contact counterface 13. In the mounted state,
the contact faces 10, 11 bear over their area against the
respective contact counterface 12, 13. The tie-up of the bridge 6
to the housing shells 2, 3 expediently takes place such that the
respective contact face 10, 11 is pressed against the respective
contact counterface 12, 13. In the variant according to FIG. 1,
this is achieved by means of a corresponding bracing between the
bridge 6 and the housing shells 2, 3 perpendicularly with respect
to the contact faces 10, 11 and contact counterfaces 12, 13, said
bracing being generated with the aid of the screw connections 9. As
a result of wide contact faces and, to an increased extent, also
due to an arrangement of the screw connection in a plurality of
rows, a good transmission of circumferential moments, even in the
case of relatively low screw forces, is achieved. The bracing
additionally results in force transmission between the contact
faces 10, 11 and the contact counterfaces 12, 13, that is to say
between the housing shells 2, 3, via the bridge 6 by means of shear
forces. In order to increase the transmittable shear forces, it may
be expedient to provide the surfaces of the contact faces 10, 11
and/or the surfaces of their contact counterfaces 12, 13 with an
increased coefficient of friction. For example, the coefficients of
friction may be increased by means of an increased roughness of the
respective surface.
[0031] In the embodiment shown here, the contact faces 10, 11 and
the contact counterfaces 12, 13 extend in a plane 14 which stands
on the parting plane 4. In the embodiment shown here, this plane 14
stands perpendicularly on the parting plane 4. The invention also
includes embodiments with contact faces standing slightly
obliquely, in particular with contact faces standing obliquely
mirror-symmetrically to the plane of symmetry of the housing,
similarly to a lift-out slope, which, in particular, simplify the
operation of mounting and demounting (FIGS. 2a and 4a).
[0032] In the embodiment according to FIG. 1, moreover, the housing
shells 2, 3 are connected directly to one another in the region of
the parting plane 4 by means of a further screw connection, which
may afford advantages in terms of machining and mounting and during
operation, particularly with regard to the leaktightness of the
housing connection. This screw connection is indicated by dashed
and dotted lines and is designated by 15. In this case, this screw
connection 15 is arranged in a conventional way such that it passes
through the parting plane 4 preferably perpendicularly. In order to
save radial installation space, and particularly when the
additional conventional screw connection serves merely for
machining or mounting, conventional screws and the bridges may
locally alternate one behind the other in the axial direction.
[0033] FIG. 1 thus shows an embodiment in which the bridge 6 can be
mounted at comparatively low outlay onto a flange region of
basically conventional configuration, in order thereby to improve
the rigidity of the flange 5 considerably. An embodiment of this
type is, in particular, retrofittable.
[0034] The bridge 6 may be dimensioned particularly simply such
that the tensile forces consequently transmittable are considerably
higher than tensile forces which can be transmitted by means of
conventional screw connections. In addition, the moment rigidity is
increased. At the same time, a bridge 6 of this type has
comparatively compact build, with the result that the outer contour
of the housing 1 is undisturbed or disturbed only slightly in terms
of it symmetry.
[0035] The bridge 6 may be configured, for example, as a plate. It
is likewise possible to configure the bridge 6 as a bar. In the
case of a plate-shaped bridge 6, a longitudinal dimension of the
bridge 6, which is measured in the parting plane 4 and in the
longitudinal direction of the housing 1, is greater than a
transverse dimension of the bridge 6, which is measured
transversely with respect to the parting plane 4, that is to say
along the plane 14. A plate-shaped bridge 6 can be anchored with
sufficient strength to the housing shells 2, 3 by means of a
corresponding number of screw connections 9. In contrast to this,
in the case of a bar-shaped bridge 6, the longitudinal dimension of
the bridge 6 is in any event smaller than the transverse dimension
of the bridge 6. Preferably, in the case of a bar-shaped bridge 6,
the longitudinal dimension of the bridge 6 lies in the region of a
thickness which is measured in the parting plane 4 and transversely
with respect to the longitudinal direction of the housing 1.
[0036] According to FIG. 2, another advantageous embodiment is
obtained when the position of the plane 14 is selected such that
the bridge 6 is located completely or virtually completely within
the rotationally symmetrical outer contour 16 of the housing 1. In
order to achieve this dimensional integration of the bridge 6, the
two housing shells 2, 3 have formed on them a corresponding
clearance 20, into which the bridge 6 is inserted with its bridge
portions 7, 8. In FIG. 2, the contact faces and contact
counterfaces 10, 11 and 12, 13 all lie in one plane, which may be
advantageous for machining, but, in the case of large housing
radii, entails relatively large bridges 6. Alternatively, in such
instances, the size of the bridge 6 may be reduced to the dimension
required for moment and force transmission, in that, according to
FIG. 2a, the contact faces and contact counterfaces 10, 11 and 12,
13 are no longer left in one plane. Either the contact faces may
remain planar, but be arranged in the form of a blunt wedge, or
they may otherwise describe any mathematically continuous or even
discontinuous curved form, which has for example, an arc of a
circle.
[0037] Preferably, the bridge 6 is designed such that an
essentially constant mass distribution is obtained over the region
of the parting plane 4 in the cross section of the housing 1 in the
circumferential direction of the latter. The housing thus possesses
largely constant flexural rigidity and, furthermore, essentially
the same thermal properties over the entire circumference, with the
result that, under the loads occurring when the machine is in
operation, a symmetrical deformation of the housing 1 is achieved
particularly simply.
[0038] While FIG. 1 reproduces an embodiment of the invention in
which the bridge 6 can be mounted onto a housing having a flange
region 5 of basically conventional configuration, the variants
according to FIG. 2 and FIG. 2a and all the following variants show
types of housing construction according to the invention which
deviate greatly from current designs according to the prior
art.
[0039] FIG. 3 shows an embodiment which is very similar to FIG. 2,
but in which the bridge 6 is not integrated completely into the
outer contour 16 of the housing 1, but, instead, projects slightly
beyond the housing contour 6 in the radial direction. As a result,
somewhat more radial space for an optimum arrangement of the screw
connection and for a further optimization of the flexural rigidity
profile is obtained, at the expense of a somewhat larger
installation space and a slightly impaired thermal behavior.
[0040] In the embodiment according to FIG. 4, the second bridge
portion 8 of the bridge 6 forms an integral part of the second
housing shell 3. That is to say, in this embodiment, the bridge 6
does not form a separate component, but is formed in one part or in
one piece on one of the housing shells 2 or 3, here on the second
housing shell 3.
[0041] Similarly to FIG. 2a, in the case of the bridge 6 integrated
into one of the housing shells 2 or 3, too, the contact face may be
designed obliquely or in the form of a curve according to FIG.
4a.
[0042] In the embodiments of FIG. 5 to 8, positive connections 17
are provided, with the aid of which the respective bridge portions
7, 8 are connected firmly to the associated housing shells 2, 3. In
this case, these positive connections 17 are in each case
configured such that they fix the two housing shells 2, 3 such that
they bear against one another along the parting plane 4. That is to
say, the positive connections 17 prevent a relative movement
between the two housing shells 2, 3 transversely with respect to
the parting plane 4.
[0043] Such additional positive connections 17 are advantageous
when high forces also have to be transmitted in addition to the
circumferential moments. In particular, they make it possible to
dimension the screw connection solely according to the moment
transmission, this usually requiring only relatively small bolts on
account of the relatively large height of the contact faces and
consequently large screw spacings, without surcharges on account of
an additional shear load to the screws having to be taken into
account.
[0044] In particular, the variant shown in FIG. 5 is a positive
connection 17 which constitutes a clamp coupling. This clamp
coupling has the advantage that it can be mounted radially with
respect to the longitudinal direction of the housing 1. In this
case, end portions 18 of the bridge 6 engage over end portions 19
of the housing shells 2, 3.
[0045] In the variant according to FIG. 6, the positive connection
17 is configured in the manner of a dovetail coupling, here the end
portions 18 of the bridge 6 likewise engaging behind complementary
end portions 19 of the housing shells 2, 3. The bridge 6 shown in
FIG. 6 has to be mounted axially with respect to the longitudinal
direction of the housing 1.
[0046] In the embodiment according to FIG. 7, the positive
connection 17 is configured in the manner of a hammerhead coupling.
Here, too, as in the variant according to FIG. 6, the end portions
19 of the housing shells 2, 3 form undercuts which engage behind
the end portions 18 of the bridge 6. Here, too, the bridge 6 can be
mounted axially.
[0047] In this type of positive connection 17, the screw
connections 9 could basically be dispensed with or be further
reduced if either the positive connection is placed approximately
in the middle of the respective contact faces, so that the moment
can be transmitted by means of the large-area support on both
sides, or in that, instead of this, in each case a second row of
such connections is arranged nearer to the parting plane 4, so that
the pairs of forces arising from the circumferential moments can
also be transmitted in the radial direction via the contact faces
by means of suitable positive connections (FIG. 7a).
[0048] In the embodiment according to FIG. 8, the positive
connection 17 is formed by form-fitting contours, transmitting
shear forces, on the contact faces 10, 11 and on the contact
counterfaces 12, 13. A detail A in this case shows a variant in
which these form-fitting contours form a kind of serration, the
respective contact face 10 being provided with axial tooth rows
engaging into complementary tooth rows which are formed on the
contact counterface 12. In contrast to this, the detail B shows
another embodiment in which the form-fitting contours have a wavy
configuration. The respective contact face 11 in this case has a
multiplicity of waves which extend essentially axially and engage
into complementary waves which are formed on the associated contact
counterface 13. In this embodiment, the screw connections 9 are
required in order to brace the contact faces 10, 11 against the
contact counterfaces 12, 13.
[0049] It is clear, in this case, that the embodiments, shown in
FIG. 8, of the form-fitting contours are purely by way of example,
so that, basically, other suitable form-fitting contours may also
be used.
[0050] Whereas, in the embodiments of FIG. 1 to 8, the contact
faces 10, 11 and the contact counterfaces 12, 13 in each case lie
in the plane 14, FIG. 9 shows an embodiment in which the contact
faces 10, 11 and the contact counterfaces 12, 13 have a curved run
and extend correspondingly along a curve. This curve is concave
toward the inside of the housing 1. This curve preferably extends
coaxially with respect to a curve of the housing shells 2, 3, that
is to say coaxially with respect to a curve of the housing 1 in the
region of the parting plane 4. As in the variant according to FIG.
2, in the embodiment according to FIG. 9, too, the housing shells
2, 3 have provided on them a clearance 20 into which the bridge 6
is inserted. In the present case, moreover, the bridge 6 and
clearance 20 are coordinated with one another such that the bridge
6 is arranged, countersunk, in the clearance and, in particular,
runs within the outer contour 16 of the housing 1.
[0051] The embodiments illustrated here are purely by way of
example and therefore without any restriction in generality. Thus,
types of housing construction other than rotationally symmetrical
likewise come under the invention. Also, such types of construction
with a horizontal parting plane and bridges arranged
perpendicularly with respect to this, that is to say vertically,
are also a very frequent embodiment, although any other spatial
orientation is likewise possible, for example a vertical parting
plane and horizontal bridges.
[0052] Furthermore, it goes without saying that individual features
of some embodiments can be combined with features of other
embodiments, without departing from the scope of the invention. In
particular, the additional features explained with reference to
FIG. 1, such as the further screw connection 15, increased
coefficients of friction in the contact faces 10, 11 and contact
counterfaces 12, 13, the shaping of the bridge 6 and the
positioning, dimensioning and number of the screw connections 9,
can be transferred directly to the other embodiments.
[0053] In particular, the various positive connections 17 and the
screw connections 9 can be combined. For example, one bridge
portion 7, 8 may be provided with a first positive connection 17,
while the other bridge portion 8 or 7 is fastened to the respective
housing shell 2, 3 by means of a second positive connection 17 or
solely by means of screw connections 9.
[0054] List of Reference Symbols [0055] 1 housing [0056] 2 first
housing shell [0057] 3 second housing shell [0058] 4 parting plane
[0059] 5 flange [0060] 6 bridge [0061] 7 first bridge portion
[0062] 8 second bridge portion [0063] 9 screw connection [0064] 10
first contact face [0065] 11 second contact face [0066] 12 first
contact counterface [0067] 13 second contact counterface [0068] 14
plane [0069] 15 screw connection [0070] 16 outer contour [0071] 17
positive connection [0072] 18 end portion of 6 [0073] 19 end
portion of 2 or 3 [0074] 20 clearance
[0075] While the invention has been described in detail with
reference to exemplary embodiments thereof, it will be apparent to
one skilled in the art that various changes can be made, and
equivalents employed, without departing from the scope of the
invention. The foregoing description of the preferred embodiments
of the invention has been presented for purposes of illustration
and description. It is not intended to be exhaustive or to limit
the invention to the precise form disclosed, and modifications and
variations are possible in light of the above teachings or may be
acquired from practice of the invention. The embodiments were
chosen and described in order to explain the principles of the
invention and its practical application to enable one skilled in
the art to utilize the invention in various embodiments as are
suited to the particular use contemplated. It is intended that the
scope of the invention be defined by the claims appended hereto,
and their equivalents. The entirety of each of the aforementioned
documents is incorporated by reference herein.
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