TURBOCHARGER

Abstract

A turbocharger, with a turbine and a compressor. A turbine housing of the turbine and a compressor housing of the compressor are connected to a bearing housing arranged between the same. A casing surrounds the turbine housing and/or the compressor housing and/or the bearing housing radially outside and axially outside at least in sections, which are connected to the respective housing to be encased via multiple fastening devices. At least one fastening device forms a fixed bearing-like connection and at least one fastening device a loose bearing-like connection of the casing on the respective housing to be encased.

Claims

1. A turbocharger, comprising: a turbine configured to expand a first medium; a compressor configured to compress a second medium utilising energy extracted in the turbine during expansion of the first medium; a turbine housing of the turbine; a compressor housing of the compressor; a bearing housing arranged between and connected to the turbine housing and the turbine housing; a casing configured to surround one or more of radially outside and axially outside at least in sections the turbine housing, the compressor housing, and the bearing housing, multiple fastening devices configured to connect the casing to the respective housing to be encased; at least one first fastening device of the multiple fastening devices configured as a fixed bearing-like connection; and at least one second fastening device of the multiple fastening devices configured as a loose bearing-like connection of the casing on the respective housing to be encased.

2. The turbocharger according to claim 1, wherein the at least one first fastening device prevents a relative movement between the casing and the respective housing to be encased, and the at least one second fastening device allows a relative movement between the casing and the respective housing to be encased in a translational direction.

3. The turbocharger according to claim 1, wherein the at least one second fastening device allows a translational relative movement between the casing and the respective housing to be encased in a radial direction.

4. The turbocharger according to claim 3, wherein on at least one axial wall of the casing the at least one first fastening device provides a fixed bearing-like connection and the at least one second fastening device a loose bearing-like connection.

5. The turbocharger according to claim 3, wherein on axial walls of the casing located opposite one another, a respective first fastening device provides a fixed bearing-like connection and a respective second fastening device provides a loose bearing-like connection.

6. The turbocharger according to claim 3, wherein a fixed bearing-like connection formed on an axial wall and a respective loose bearing-like connection formed on a same axial wall lie on an axis that extends in a radial direction.

7. The turbocharger according to claim 1, wherein the loose bearing-like connection allows a translational relative movement between the casing and the respective housing to be encased in an axial direction.

8. The turbocharger according to claim 7, wherein on an axial wall of the casing a respective fastening device provides a fixed bearing-like connection and on a radial wall of the casing and a respective fastening device provides a loose bearing-like connection.

9. The turbocharger according to claim 1, wherein a respective first fastening device, which forms a fixed bearing-like connection, extends without play or almost without play through a recess in a respective wall of the casing.

10. The turbocharger according to claim 1, wherein a respective second fastening device, which forms a loose bearing-like connection, extends through an elongated hole in a respective wall of the casing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Preferred further developments of the invention are obtained from the subclaims and the following description. Exemplary embodiments of the invention are explained in more detail by way of the drawing without being restricted to this. There it shows:

[0014] FIG. 1 is a lateral view of a turbocharger according to one aspect of the invention in the region of a housing of the turbocharger and of a casing of the housing in axial viewing direction;

[0015] FIG. 2 is a cross section of a first detail of FIG. 1; and

[0016] FIG. 3 is a cross section of a second detail of FIG. 1.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0017] The fundamental construction of a turbocharger is familiar to the person skilled in the art addressed here. Accordingly, a turbocharger comprises a turbine for expanding a first medium, in particular for expanding exhaust gas, and a compressor for compressing a second medium, in particular for compressing charge air, utilising energy extracted in the turbine during the expansion of the first medium.

[0018] The turbine comprises a turbine rotor and a turbine housing. The compressor comprises a compressor rotor and a compressor housing. The turbine rotor and the compressor rotor are coupled via a shaft mounted in a bearing housing of the turbocharger, wherein the bearing housing is connected both to the turbine housing and also to the compressor housing.

[0019] When during the operation the turbine rotor or the compressor rotor breaks, fragments of the same can strike through the respective housing, i.e. the turbine housing or the compressor housing, and enter the surroundings. This has to be avoided for the purpose of which it is known to equip a turbocharger with a casing which surrounds the turbine housing and/or the compressor housing and/or the bearing housing of the turbocharger.

[0020] Preferentially, a separate casing each is employed in the region of the turbine housing and of the compressor housing which surrounds the respective casing of the turbocharger to be encased radially outside and axially outside at least in sections.

[0021] Such casings provide a burst protection and can also serve for thermally insulating and sound insulating assemblies of the turbocharger.

[0022] FIG. 1 shows a lateral view of a turbocharger in the region of a turbine housing 1 and of a casing 2, which surrounds the turbine housing 1 on the outside at least in sections. The concrete construction of the casing 2 is of no significance regarding the invention present here.

[0023] FIG. 1 shows a lateral view in the axial viewing direction of the encased housing 1 of a turbocharger, which is surrounded by the casing 2 on the outside at least in sections. The encased housing 1 is in particular the turbine housing of the turbine of a turbocharger.

[0024] The casing 2 comprises axial walls 3 and radial walls 4. Accordingly an axial wall 3 of the casing 2 is arranged preferentially on each axial side of the housing 1 to be encased, which axially covers the respective housing 1 to be encased at least in sections. Radially outside, a radial wall 4 of the casing 2 covers the respective housing 1 to be encased at least in sections.

[0025] The casing 2 is connected to the housing 1 to be encased via fastening devices 5, 6. Here, both at least one axial wall 3 of the casing 2 as well as also the radial wall 4 of the casing 2 can be connected to the housing to be encased via fastening devices.

[0026] In FIG. 1, fastening devices 5, 6 are shown via which the axial wall 3 that is visible in FIG. 1 is connected to the housing 1 to be encased.

[0027] FIG. 2 shows a cross section through the arrangement of FIG. 1 in the region of the fastening device 5. FIG. 3 shows a cross section through the arrangement of FIG. 1 in the region of the fastening device 6.

[0028] According to one aspect of the invention, it is provided that at least one fastening device, which serves for fastening the casing 2 to the housing 1 to be encased, forms a fixed bearing-like connection of the casing 2 on the housing 1 to be encased, and that at least one further fastening device forms a loose bearing-like connection of the casing 2 on the respective housing 1 to be encased.

[0029] In FIG. 1, the fastening device 5 forms a fixed bearing-like connection and the fastening device 6 a loose bearing-like connection of the casing 2 on the respective housing 1 to be encased. The fastening devices 5, 6 extend through the casing 2 into the housing 1 to be encased. The fastening device 5, which forms a fixed bearing-like connection of the casing 2 on the housing 1 to be encased and extends through the axial wall 3 of the casing 2 into the housing 1 to be encased and prevents a local relative movement between the casing 2 and the respective housing 1 to be encased. The fastening device 6, by contrast, which forms a loose bearing-like connection of the casing 2 on the housing 1 to be encased and extends through the axial wall 3 of the casing 2 into the housing 1 to be encased, allows a local relative movement between the casing 2 and the housing 1 to be encased in a single translational direction.

[0030] In the exemplary embodiment of FIGS. 1 to 3, the respective loose bearing-like connection in the region of the fastening device 6 allows a translational relative movement between the casing 2 and the respective housing 1 to be encased in the radial direction. Here it is provided in the exemplary embodiment of FIGS. 1 to 3 that on axial walls 3 of the casing 2 located opposite one another a fastening device 5 in each case provides a fixed bearing-like connection and in each case a fastening device 6 a loose bearing-like connection.

[0031] From FIG. 1 it is evident that the fastening devices 5, 6 acting on the axial wall 3 that is visible in FIG. 1 on the one hand form the fixed bearing-like connection in the region of the fastening device 5 and on the other hand the loose bearing-like connection in the region of the fastening device 6, lie on an axis extending in the radial direction. Here, the fastening device 5, which forms the fixed bearing-like connection, extends without play or almost without play through a recess in the axial wall 3 into the housing 1 to be encased. The fastening device 6 by contrast, which forms the loose bearing-like connection of the casing 2 on the housing 1 to be encased, extends through a recess of the respective axial wall 3 formed as elongated hole 8 into the housing 1 to be encased and is guided in the elongated hole 8.

[0032] The fastening devices 5, which provide fixed bearing-like connections and which are formed on axial walls 3 located opposite one another, lie on a first axis extending in the axial direction. Loose bearing-like connections formed on axial walls 3 located opposite one another or the fastening devices 6, which form such loose bearing-like connections, lie on a second axis extending in the axial direction, which preferentially run parallel to the first axis.

[0033] The elongated hole 8, which is formed in the axial wall 3 and together with the fastening device 6 provides the loose bearing-like connection extends in the radial direction of the housing 1 to be encased. In the exemplary embodiment of FIG. 1, the respective loose bearing-like connection accordingly allows a translational relative movement between the casing 2 and the respective housing 1 to be encased in the radial direction.

[0034] Alternatively it is also possible that a respective loose bearing-like connection allows a translational relative movement between the casing 2 and the respective housing 1 to be encased in the axial direction.

[0035] In particular when a loose bearing-like connection allows a translational relative movement between the casing 2 and the respective housing 1 to be encased in the axial direction it is provided, in particular, that on an axial wall 3 of the casing 2 a fastening device, which extends through the wall 3 of the casing 2 into the housing 1 to be encased, provides a fixed bearing-like connection and that on a radial wall of the casing 2 a fastening device, which extends through the radial wall 4 of the casing 2 into the housing 1 to be encased, provides a loose bearing-like connection. To this end, an elongated hole extending in the axial direction can be formed in the region of the radial wall 4 in which the fastening device is guided.

[0036] With the invention, a defined relative movement between the housing 1 to be encased and the casing 2 is possible in particular with a housing 1 of a turbocharger to be encased exposed to cyclical thermal loads. Forces, which brought about by a cyclical thermal loading of the housing 1 can be introduced into the casing 2 via the fastening devices can be reduced. Damages to the housing 1 to be encased, the fastening devices 4, and the casing 2 can thus be avoided. At least one fastening device forms a fixed bearing-like and at least one other fastening device provides a loose bearing-like connection of the casing 2 on the housing 1 in order to make possible a defined relative movement between the casing 2 and the housing 1 to be encased. Furthermore, vibrations of the casing 2 are avoided.

[0037] Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.