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).

Description

This application claims priority under 35 U.S.C. § 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

1. Field of the Invention

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.

2. Brief Description of the Related Art

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.

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.

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.

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.

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.

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.

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.

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.

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.

Finally, U.S. Pat. No. 2,169,092 proposes use of double T-shaped shrunk-in ties instead of bolts.

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.

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.

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

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.

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.

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.

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.

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.

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

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,

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

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

List of Reference Symbols

• 1 housing
• 2 first housing shell
• 3 second housing shell
• 4 parting plane
• 5 flange
• 6 bridge
• 7 first bridge portion
• 8 second bridge portion
• 9 screw connection
• 10 first contact face
• 11 second contact face
• 12 first contact counterface
• 13 second contact counterface
• 14 plane
• 15 screw connection
• 16 outer contour
• 17 positive connection
• 18 end portion of 6
• 19 end portion of 2 or 3
• 20 clearance

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.

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.