Exhaust gas turbocharger

Abstract

Exhaust gas turbocharger (1) - with a compressor (2) which has a compressor housing (3); - with a turbine (4) which has a turbine casing (5), and - with a bearing housing (6) which is arranged between the compressor housing (3) and the turbine housing (5) and is connected to the compressor housing (3) via a compressor-side connection device and to the turbine housing (5) via a turbine-side connection device (7), - wherein the turbine-side and / or compressor-side connection device (7) is designed as a wedge connection, which has screws (8, 9, 10) which are arranged at least substantially perpendicular to an exhaust gas turbocharger longitudinal axis (L), characterized in that the wedge connection (7) has a number of wedge blocks (12, 13, 14) distributed around an inner circumference (U) of a turbine housing flange (11) and / or compressor housing flange corresponding to the number of screws (8, 9, 10), each of which is provided with an internal thread (15, 16, 17).

Description

[0001] The invention relates to an exhaust gas turbocharger according to the preamble of claim 1.

[0002] For connecting a turbine housing and a bearing housing of an exhaust gas turbocharger, screws or stud bolts extending in the direction of the longitudinal axis of the exhaust gas turbocharger, screw connections on the spiral circumference of the compressor housing with long screws, clamping band connections or segment screw connections are known.

[0003] The problem with such connecting devices is often inadequate accessibility and thus a complication of assembly.

[0004] DE 10 2009 052 961 A1 discloses an exhaust gas turbocharger with a bearing housing for supporting a rotor shaft and with a compressor housing for receiving a compressor wheel. A clamping device has a first arm portion and an engagement portion, wherein the first arm portion rests at least partially on a surface of the bearing housing. A counter-clamping device has a head portion and a counter-engagement portion, wherein the head portion rests at least partially on a first surface of the compressor housing, and wherein the counter-engagement portion can be brought into positive contact with the engagement portion such that the bearing housing and the compressor housing can be non-positively connected to one another.

[0005] DE 27 06 105 A1 shows a device for clamping the connecting flanges of two machine housings together, which comprises clamp-like clamping claws distributed over the circumference of the connecting flanges, which clamp both connecting flanges together by means of clamping surfaces arranged on the clamping claws, by means of counter surfaces formed accordingly on the connecting flanges and by means of clamping screws arranged radially to the connecting flanges and leading through the clamping claws.

[0006] EP 0 775 863 A1 shows a one-piece sleeve comprising two collars with integral tubular or cylindrical extensions. Wedge-shaped clamping elements are inserted between the inner conical contact surfaces of the sleeve and the flat surfaces of the collars in the direction of the screw axis using tension screws. The collars are clamped to the sleeve via the wedge-shaped clamping elements.

[0007] It is therefore an object of the present invention to provide an exhaust gas turbocharger of the type specified in the preamble of claim 1, which is provided with a connecting device between the bearing housing and the turbine housing and / or between the bearing housing and the compressor housing, which is easily accessible and easy to install.

[0008] This problem is solved by the features of claim 1.

[0009] A wedge screw connection is provided with a number of wedge blocks distributed around an inner circumference of a turbine housing flange and / or compressor housing flange, each of which is provided with an internal thread, corresponding to the number of screws.

[0010] This ensures that the connecting device in the form of the wedge screw connection has radially accessible screws that can be inserted through a flange of the turbine housing and / or the compressor housing and fixed.

[0011] Alternatively, it is provided that a connecting device has a number of clamping elements corresponding to the number of screws, which are arranged distributed on an inner circumference of a turbine housing flange and / or compressor housing flange and each have an internal thread for the screws and each have a nose provided with an inclined surface, which engage in a groove of the turbine housing flange and / or compressor housing flange and are provided with a turbine housing inclined surface and / or compressor housing inclined surface facing away from the turbine housing or the compressor housing and complementary to the inclined surface of the nose.

[0012] The subclaims contain advantageous developments of the invention.

[0013] The wedge screw connection of the connecting device according to the invention has a number of wedge blocks provided with an internal thread, corresponding to the number of screws, which are distributed along an inner circumference of the turbine / compressor housing flange. After the screws have been inserted through the turbine housing flange or compressor housing flange, the screws can be screwed into the wedge blocks. Tightening the screws causes the wedge blocks to be pulled radially outward, preferably sliding over an inclined surface arranged on the bearing housing along a complementary inclined surface formed on the wedge block. The interaction of these inclined surfaces applies a preload force in the longitudinal or main axis direction of the exhaust gas turbocharger.

[0014] In a variant of the wedge screw connection according to the invention, it is possible to press clamping elements with wedge-shaped lugs into a groove located on the turbine housing / compressor housing. A complementary inclined surface facing away from the turbine housing / compressor housing is formed in the groove, on which the inclined surface of the lug rests. The axial preload force is applied by the complementary inclined surfaces when the screw is tightened.

[0015] In another variant, the force acting on the screws is reversed. Here, the screws rest radially on a bearing housing wall area, forcing the clamping element into the groove of the turbine housing / compressor housing.

[0016] The subclaims contain advantageous developments of the invention.

[0017] Further details, advantages, and features of the present invention will become apparent from the following description of exemplary embodiments with reference to the drawings. It shows: Fig. 1 a schematically highly simplified representation of an exhaust gas turbocharger according to the invention, which can be provided with a connecting device according to the invention for connecting the bearing housing and the turbine housing, Fig. 2 a sectional view of a first embodiment of the exhaust gas turbocharger according to the invention or the connecting device according to the invention, Fig. 3 one of the Fig. 2 corresponding representation of a second embodiment, and Fig. 4 one the Fig. 2 and Fig. 3 corresponding representation of a third embodiment.

[0018] In Fig. 1 shows a schematically highly simplified representation of an exhaust gas turbocharger 1 which has as the usual basic components a compressor 2 with a compressor housing 3 and a turbine 4 with a turbine housing 5.

[0019] Between the compressor housing 3 and the turbine housing 5, a bearing housing 6 is arranged in which a rotor shaft 32 is mounted, which is provided at its two ends with a compressor wheel and a turbine wheel, respectively.

[0020] The bearing housing 6 is fastened to both the compressor housing 3 and the turbine housing 5, wherein a connecting device according to the invention for attaching the bearing housing 6 to the turbine housing 5 is shown below by way of example with reference to the Fig. 2 to 4. However, the connecting device according to the invention can also be used on the compressor side.

[0021] Fig. Figure 2 shows a first embodiment of a connecting device 7, which in the illustrated example has three of four screws 8, 9 and 10, which in the example are each arranged offset by 90° to each other. The screws 8, 9 and 10 are inserted through a turbine housing flange 11 and in the embodiment according to Fig. 2 screwed into the internal threads 15, 16, 17 of associated wedge blocks 12, 13 and 14 respectively.

[0022] As shown by the, according to the Fig. As can be seen from the upper partial connection shown in Figure 2, the wedge blocks each have inclined surfaces 19 which rest on a complementarily formed inclined surface 20 of a bearing housing flange 18. By tightening the screws 8, 9 and 10, the associated wedge blocks 12, 13 and 14, respectively, are pulled radially outwards, whereby the inclined surfaces 19 and 20 slide on one another and thus an axial preload force is applied in the main axis direction L of the exhaust gas turbocharger 1.

[0023] In the embodiment according to Fig. 3, the connecting device 7 again has three of four screws 8, 9 and 10, which are inserted through the turbine housing flange 11 and engage in the internal threads 24, 25 and 26 of associated clamping elements 21, 22 and 23.

[0024] The clamping elements 21, 22 and 23 are each designed identically, so that reference is made to the clamping element 21 as a representative example of their structure. Fig. Figure 3 illustrates that the clamping element 21 has a nose 28 provided with an inclined surface 27. The nose 28 engages in a groove 29 of the turbine housing flange 11 and, in this position, rests on a complementarily formed inclined turbine housing surface 30. By tightening the screws 8, 9, and 10, the clamping elements are again pulled radially outward, with the inclined surfaces 29 and 30 sliding against one another generating the axial preload force.

[0025] The embodiment according to Fig. 4 corresponds to that of the clamping elements 21, 22 and 23 with their respective noses 28 and the complementary inclined surfaces 29 and 30 Fig. 3. In the design of the Fig. 4, however, the force effect of the screws 8, 9 and 10 is compared to the embodiment of the Fig. 3 is reversed, since the screws 8, 9 and 10 are supported at the end on a bearing housing wall area 31, whereby the clamping elements 21, 22 and 23 are pressed into the groove 29 when the screws 8, 9 and 10 are tightened, whereby the axial preload force is generated.

[0026] In addition to the above written disclosure of the invention, explicit reference is hereby made to the graphic representation in the Fig. 1 to 4 are referred to. List of reference symbols 1 exhaust gas turbocharger 2 compressors 3 Compressor housing 4 turbines 5 Turbine housing 6 bearing housings 7 Connecting device 8, 9, 10 screws 11 Turbine housing flange 12, 13, 14 wedge blocks 15, 16, 17 internal thread 18 Bearing housing flange 19, 20 inclined surfaces 21, 22, 23 clamping elements 24, 25, 26 thread 27 Inclined surface 28 Nose 29 grooves 30 Inclined surface 31 Bearing housing wall area 32 Rotor shaft L Longitudinal axis or main axis direction of the exhaust gas turbocharger U inner circumference

Claims

[1] Exhaust gas turbocharger (1) - with a compressor (2) having a compressor housing (3); - with a turbine (4) having a turbine housing (5), and - with a bearing housing (6) which is arranged between the compressor housing (3) and the turbine housing (5) and is connected to the compressor housing (3) via a compressor-side connecting device and to the turbine housing (5) via a turbine-side connecting device (7), - wherein the turbine-side and / or compressor-side connecting device (7) is designed as a wedge screw connection having screws (8, 9, 10) which are arranged at least substantially perpendicular to a longitudinal axis (L) of the exhaust gas turbocharger, characterized bythat the wedge screw connection (7) has a number of wedge blocks (12, 13, 14) corresponding to the number of screws (8, 9, 10) distributed on an inner circumference (U) of a turbine housing flange (11) and / or compressor housing flange, each of which is provided with an internal thread (15, 16, 17). [2] Exhaust gas turbocharger according to claim 1, characterized by that the wedge blocks (12, 13, 14) and a bearing housing flange (18) arranged adjacent to them have complementary inclined surfaces (19 and 20 respectively) lying on top of one another. [3] Exhaust gas turbocharger - with a compressor (2) having a compressor housing (3); - with a turbine (4) having a turbine housing (5), and - with a bearing housing (6) which is arranged between the compressor housing (3) and the turbine housing (5) and is connected to the compressor housing (3) via a compressor-side connecting device and to the turbine housing (5) via a turbine-side connecting device (7), - wherein the turbine-side and / or compressor-side connecting device (7) is designed as a wedge screw connection having screws (8, 9, 10) which are arranged at least substantially perpendicular to a longitudinal axis (L) of the exhaust gas turbocharger, characterized byin that the connecting device (7) has a number of clamping elements (21, 22, 23) corresponding to the number of screws (8, 9, 10), which are arranged in a distributed manner on an inner circumference (U) of a turbine housing flange (11) and / or compressor housing flange and each have an internal thread (24, 25, 26) for the screws (8, 9, 10) and each have a nose (28) provided with an inclined surface (27), which engage in a groove (29) of the turbine housing flange (11) and / or compressor housing flange and are provided with a turbine housing inclined surface (30) and / or compressor housing inclined surface facing away from the turbine housing (5) or the compressor housing (3) and complementary to the inclined surface (27) of the nose (28). [4] Exhaust gas turbocharger according to claim 3, characterized by that the screws (8, 9, 10) are supported radially on a bearing housing wall area (31). [5] Exhaust gas turbocharger according to claims 1 to 4, characterized bythat the screws (8, 9, 10) are designed as Allen screws.

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