Turbomachine with heat shield

Abstract

The invention relates to a turbomachine (10). The turbomachine (10) comprises a shaft (12) which is mounted in a bearing housing (11) and on which a rotor (13) is located. The turbomachine (10) further comprises a heat shield (14), which is located between the bearing housing (11) and a gas outlet housing (15) of the turbomachine. The heat shield (14) has a radially outer fastening element receptacle (141) for fastening the heat shield (14) to the bearing housing (11) using a fastening element (16). The fastening element receptacle (141) is located between the bearing housing (11) and the gas outlet housing (15). The fastening element receptacle (141) is an axial fastening element receptacle. The fastening element (16) extends through the axial fastening element receptacle.

Description

TURBOMACH WITH HEATSHIELD TECHNICAL AREA

[0001] The invention relates to the field of turbomachinery, in particular exhaust gas turbines. Specifically, the invention relates to a turbomachine with a heat shield. TECHNICAL BACKGROUND

[0002] Exhaust gas turbochargers are now standard equipment for increasing the power output of internal combustion engines. These turbochargers consist of a turbine located in the engine's exhaust system and a compressor positioned upstream of the engine. The exhaust gases from the engine are expanded in the turbine. The work generated during this expansion is transferred via a shaft to the compressor, which compresses the air supplied to the engine. By using the energy from the exhaust gases to compress the air supplied to the combustion process in the engine, the combustion process and the engine's efficiency can be optimized.

[0003] In turbomachinery, particularly in exhaust gas turbochargers, so-called heat shields are frequently used. The primary function of heat shields is to reduce the heat input from the turbine side into the bearing housing. There are essentially two different designs for heat shields. On the one hand, heat shields are designed as solid, machined, and partially cast components; on the other hand, there are also versions made from sheet metal forming parts. for application. Both variants are usually clamped on the outer circumference.

[0004] It has been found that heat shields known from the prior art can still be improved, especially with regard to their fastening and thermal insulation efficiency, particularly in the area of ​​fastening the heat shield.

[0005] The object of the present invention is to provide a turbomachine with a heat shield which can partially or completely overcome one or more disadvantages known from the prior art. BRIEF DESCRIPTION OF THE INVENTION

[0006] To solve the aforementioned problems, a turbomachine with a heat shield according to the independent claim is provided. Further aspects, advantages, and features of the present invention can be found in the dependent claims, the description, and the accompanying figures.

[0007] According to one aspect of the invention, a turbomachine, in particular an exhaust gas turbine, is provided. The turbomachine comprises a shaft supported in a bearing housing on which a rotor is arranged. Furthermore, the turbomachine comprises a heat shield arranged between the bearing housing and a gas outlet housing of the turbomachine. The heat shield has a radially outer mounting receptacle for attaching the heat shield to the bearing housing by means of a fastener. The mounting receptacle is arranged between the bearing housing and the gas outlet housing, and the mounting receptacle is an axial mounting receptacle. The fastener extends through the axial mounting receptacle.

[0008] Thus, a turbomachine with a heat shield is advantageously provided which, compared to turbomachines with heat shields known from the prior art, is improved with regard to the reduction of heat input from the turbine side into the bearing housing. In particular, the embodiments described herein can advantageously reduce the heat transfer between the gas outlet housing and the mounting of the heat shield. BRIEF DESCRIPTION OF THE FIGURES

[0009] The invention will now be explained with reference to exemplary embodiments illustrated in the figures, from which further advantages and modifications will become apparent. These figures show: Figure 1 shows a schematic sectional view of a turbomachine according to the embodiments described herein; Figure 2 shows a schematic sectional view of a section of a turbomachine with a heat shield attachment according to the embodiments described herein; and Figure 3 shows a schematic sectional view of a section of a turbomachine with a heat shield attachment according to further embodiments described herein with a cooling structure. DETAILED DESCRIPTION OF THE FIGURES

[0010] The following describes various embodiments, one or more examples of which are shown in each figure. Each example serves for illustration and is not to be understood as a limitation. For example, features that are part of The modifications and variations shown or described in one embodiment may be used on or in combination with any other embodiment to obtain a further embodiment. It is intended that this disclosure includes such modifications and variations.

[0011] In the following description of the drawings, the same reference numbers refer to the same or similar components. Generally, only the differences between the individual embodiments are described. Unless otherwise stated, the description of a part or aspect in one embodiment may also refer to a corresponding part or aspect in another embodiment.

[0012] With reference to Figures 1 and 2, a turbomachine 10 according to embodiments of the present disclosure is described. In particular, the turbomachine 10 can be an exhaust gas turbine. For example, the exhaust gas turbine can be an axial exhaust gas turbine. The exhaust gas turbine can be part of an exhaust gas turbocharger. It is further noted that the axial direction x and the radial direction r, to which reference is made below, are shown by way of example in the figures.

[0013] According to one embodiment, which can be combined with other embodiments described herein, the turbomachine 10 comprises a shaft 12 supported in a bearing housing 11, on which a rotor 13 is arranged. A bearing housing can be understood to be a structural component of the turbomachine that serves to house and protect bearings for supporting the shaft coupled to the rotor. The rotor can, for example, be a turbine wheel. In particular, the rotor can be a turbine disk. A turbine disk typically comprises blades or vanes mounted on a disk-shaped structure. Furthermore, the turbomachine 10 comprises a heat shield 14, which is located between the bearing housing 11 and a gas outlet housing 15 of the turbomachine.

[0014] A heat shield can be understood as a structural component designed to dissipate heat energy from a hot source and protect surrounding components from excessive heat. In the context of a turbomachine, the heat shield is typically arranged to provide thermal insulation and protect the bearing housing from high temperatures. Typically, the heat shield is a single component. In other words, the heat shield is typically provided by a single, continuous, undivided part. The heat shield is typically rotationally symmetrical and includes a central opening for the shaft.

[0015] As illustrated by way of example in Figure 1, the heat shield 14 has one or more radially outer fastening receptacles 141 for attaching the heat shield 14 to the bearing housing 11 by means of one or more fastening means 16. The fastening means can be, for example, screws, bolts, pins, rivets, or other suitable fastening means. Preferably, the fastening means are releasable, such as screws. In particular, the fastening means described herein can be screws whose length is selected such that self-locking of the screw can be ensured. The screw length typically has an influence on the self-locking properties, especially with regard to preventing the unintentional loosening of the screw, for example, due to vibrations, loads, or other external influences.A longer screw provides a larger contact area between the screw and the material into which it is driven. This increases the frictional force that holds the screw in place and reduces the likelihood of it loosening due to vibration or stress. A longer screw can also help improve stress distribution at the fastening point. The longer screw... The load is distributed over a larger area, which reduces the load concentration and increases the strength of the connection.

[0016] A radially outer fastening receptacle 141 of the heat shield 14 can be understood as a fastening receptacle that is arranged in the radial direction closer to the outer edge of the heat shield than to the center of the heat shield. A radially outer region of the heat shield in which a fastening receptacle 141 described herein is arranged typically extends over a radial region r of 0.6*R < r < R, in particular 0.7*R < r < R, in particular 0.8*R < r < R, where R is the radius of the heat shield.

[0017] The one or more fastening receptacles 141 are arranged between the bearing housing 11 and the gas outlet housing 15. Specifically, only the one fastening receptacle 141 or the multiple fastening receptacles 141 and only the corresponding fastener(s) 16 are arranged between the bearing housing 11 and the gas outlet housing 15. In other words, typically, apart from the fastening receptacles and the corresponding fasteners, no other components are arranged in the area where the heat shield 14 is attached between the bearing housing 11 and the gas outlet housing 15. It should be noted that typically several fastening receptacles 141 are provided, distributed around the circumference, to attach the heat shield 14 to the bearing housing 11 using multiple fasteners 16.In particular, the heat shield can have two, three, four, five or more mounting points 141.

[0018] According to one embodiment, which can be combined with other embodiments described herein, a first air-filled insulation space 17 is provided between the fastening receptacle 141 and the gas outlet housing 15. In the present disclosure, An air-filled insulation space can be understood as a cavity or chamber filled with air that serves to create an insulating barrier. The first air-filled insulation space 17 typically serves to create an insulating barrier between the gas outlet housing 15 and the fastening receptacle 141. This advantageously reduces the heat transfer between the gas outlet housing and the fastening receptacle.

[0019] In other words, the air-filled insulation space can act as a buffer zone or intermediate space, absorbing, distributing, and reducing heat energy transported by the gas in the gas outlet housing. By using air as the insulating medium, the insulation space can help lower the temperature at the heat shield mounting point, thereby reducing the thermal load on the mounting surface and the surrounding bearing housing.

[0020] According to one embodiment, which can be combined with other embodiments described herein, a second air-filled insulation space 18 is provided between a radially outer region 144 of the heat shield 14 and the bearing housing 11, as shown by way of example in Figure 1.

[0021] Typically, the first air-filled insulation space 17 extends in the radial direction r between Ri min and Rimax (Rimin < r < R imax In particular, the first air-filled insulation space 17 is a space that extends circumferentially around the central axis of rotation 121 of the shaft 12. For example, the first air-filled insulation space 17 can be a rotationally symmetric space.

[0022] The second air-filled insulation space 18 extends in the radial direction r typically between R 2min and R 2max (R 2min < r < R 2max ). In particular, the second air-filled insulation space 18 is a space that extends circumferentially around the central axis of rotation 121 of the shaft 12. For example, the second air-filled insulation space 18 can be a rotationally symmetric space.

[0023] Typically, the maximum radial extent is R? may the distance of the second air-filled insulation space 18 from the central axis of rotation 121 of the shaft 12 is less than the maximum radial extent Rimax of the first air-filled insulation space 17 (R2max < Rimax)-

[0024] Furthermore, the minimum radial extent R2min of the second air-filled insulation chamber 18 from the central axis of rotation 121 of the shaft 12 is typically less than the minimum radial extent Ri min of the first air-filled isolation chamber 17 Rimin)-

[0025] Furthermore, Ri min smaller than R 7rna be x (Ri min < R2max), as exemplified in Figure 1. Alternatively, Ri can min be greater than R2max (Rimin > R2max) : (not explicitly depicted in the characters).

[0026] As illustrated by way of example in Figure 1, the heat shield 14, according to one embodiment which can be combined with other embodiments described herein, provides a bearing housing-side side wall 21 of a gas outlet channel 20 of the turbomachine.

[0027] According to one embodiment, which can be combined with other embodiments described herein, a third air-filled insulation space 19 is provided between the bearing housing-side side wall 21 of the gas outlet channel 20 and the bearing housing 11. Typically, the third air-filled insulation space 19 extends along the bearing housing-side rear of the bearing housing-side side wall 21 of the gas outlet channel 20. Typically, the third air-filled insulation space 19 is a space that extends circumferentially around the central axis of rotation 121 of the shaft 12. For example, the third air-filled isolation space 19 should be a rotationally symmetric space.

[0028] According to one embodiment, which can be combined with other embodiments described herein, the bearing housing 11 includes an oil chamber 111. The oil chamber is typically thermally shielded by the heat shield described herein to prevent coking of the oil. For example, the oil chamber could then be an emergency oil tank integrated into the bearing housing.

[0029] The fastening receptacle 141 typically contacts the bearing housing 11 in a radially outer region 112 of the bearing housing 11. This contact can occur in a region of the bearing housing where the oil chamber 111 is located. Alternatively, the contact can occur in a region where the oil chamber 111 is only partially located. Another alternative is that the contact can occur in a region where no oil chamber 111 is located. In particular, the contact can occur in a region of the bearing housing that is radially further outward than the oil chamber 111.

[0030] According to one embodiment, which can be combined with other embodiments described herein, the one or more fastening means 16 by means of which the heat shield 14 is / are attached to the bearing housing can extend into one or more cooling structures 117, as shown by way of example in Fig. 3. For example, the one or more cooling structures 117 can be arranged in the oil chamber 111 of the bearing housing 11. Thus, the heat input from the turbine side can advantageously be dissipated in a controlled manner into the bearing housing, and in particular into the cooling structures.

[0031] According to one embodiment, which can be combined with other embodiments described herein, the one or more cooling structures 117 arranged in the oil chamber 111 of the bearing housing 11 are webs. For example, the one or more cooling structures 117 can be axial webs. In other words, the one or more cooling structures typically extend in a substantially axial direction into the oil chamber 111. By a “substantially axial direction” is a direction with an angular tolerance T of T <t20°, insbesondere T<tl0°, von der axialen Richtung zu verstehen. Wie es in Figur 1 beispielhaft dargestellt ist, verläuft die axiale Richtung x typischerweise entlang der Rotationsachse 121 der Welle 12, auf welcher der Rotor 13 angeordnet ist, wie es beispielsweise in Figur 1 eingezeichnet ist.

[0032] According to one embodiment, which can be combined with other embodiments described herein, the one or more cooling structures 117 are connected to a turbine-side bearing housing wall 114, as illustrated by way of example in Figure 3. In particular, the one or more cooling structures 117 can be formed integrally with the turbine-side bearing housing wall 114. Typically, the one or more fastening means 16 extend through the turbine-side bearing housing wall 114 without contact. In other words, in the region of the turbine-side bearing housing wall 114, the one or more fastening means 16 can be surrounded by an air jacket 118, as illustrated by way of example in Figure 3.

[0033] According to one embodiment, which can be combined with other embodiments described herein, the turbine-side bearing housing wall 114 has one or more threadless fastening receptacles 115 through which the one or more fastening means 16 extend without contact, as illustrated by way of example in Figure 3. The one or more threadless Fastening device receptacles 115 can, for example, be designed to provide the aforementioned air jacket 118.

[0034] Typically, the one or more unthreaded fastening receptacles 115 extend in a substantially axial direction. For example, the one or more unthreaded fastening receptacles 115 can be one or more bores through which the one or more fastening elements 16 extend without contact. Furthermore, the one or more fastening receptacles 115 can have a turbine-side countersink 116, as shown, for example, in Figure 3. For example, the turbine-side countersink 116 of the one or more fastening receptacles 115 can be designed as conical countersinks or flat countersinks. The countersinks reduce the contact of the fastening elements with the bearing housing, which has a positive effect on reducing heat input into the bearing housing.

[0035] According to one embodiment, which can be combined with other embodiments described herein, the fastening element 16, which extends into a cooling structure described herein, is a screw that engages with an internal thread provided in the cooling structure. Typically, the internal thread is provided exclusively in the cooling structure. Furthermore, the external thread of the screw, which extends into one of the cooling structures described herein, can be provided exclusively in a front end region of the screw that engages with the internal threads of the cooling structure.

[0036] It should be noted that the design of the fastening described herein, in particular the contactless extension of the fastening elements through the turbine-side bearing housing wall and the provision of the threads in the area of ​​the cooling structures, allows heat to be dissipated from the turbine side into the bearing housing in a controlled manner. Furthermore Advantageously, the screw length can be selected such that self-locking of the screw is ensured. Furthermore, it should be noted that the features described in connection with the embodiment shown in Figure 3, with regard to the one or more threadless fastening receptacles 115 and / or the countersink 116, and / or the air jacket 118, can be transferred to the embodiments shown in Figures 1 and 2.

[0037] According to one embodiment, which can be combined with other embodiments described herein, a radial gap S is provided between the fastener receptacle 141 and the gas outlet housing 15. Typically, the radial gap S is filled with air and acts as a heat transfer barrier, which has a positive effect on reducing the heat input into the fastener receptacle 141.

[0038] According to one embodiment, which can be combined with other embodiments described herein, the fastener receptacle 141 is an axial fastener receptacle. An axial fastener receptacle can be understood as a receptacle that serves to accommodate fasteners in the axial direction x.

[0039] According to one embodiment, which can be combined with other embodiments described herein, the bearing housing 11 has a seat 113, in particular a radial seat, for a complementary seat 142 of the heat shield 14.

[0040] In the present disclosure, the terms "seat" and "complementary seat" refer to two matching surfaces or structures that cooperate to enable stable and accurate positioning or mounting of the heat shield 14 on the bearing housing 11.

[0041] Typically, the term "seat" refers to a structural A device or recess in the bearing housing 11 that helps to secure or position the heat shield 14. The seat 113 can, for example, be realized by a step in the radial direction r, as shown by way of example in Figure 2. Furthermore, the seat typically comprises a circumferential surface 113U extending in the axial direction. The radial position of the seat can, for example, correspond to the radial position of the minimum radial extent R. 2mm of the second air-filled insulation space, as exemplified in Figure 1.

[0042] The complementary seat 142 refers to the corresponding surface or structure of the heat shield 14 that fits precisely into or onto the seat 113 of the bearing housing 11. The complementary seat is designed to ensure a precise fit between the bearing housing and the heat shield. In other words, the seat 113 and the complementary seat 142 are typically configured geometrically to allow for precise alignment and positioning of the heat shield within the bearing housing.

[0043] According to one embodiment, which can be combined with other embodiments described herein, the complementary seat 142 of the heat shield 14 is connected to the fastening receptacle 141 via a substantially radially extending web 143. Typically, the web 143 provides part of a wall of the first air-filled insulation chamber 17. Furthermore, the web 143 can provide part of a wall of the second air-filled insulation chamber 18. In particular, the web can be arranged between the first air-filled insulation chamber 17 and the second air-filled insulation chamber 18, as illustrated by way of example in Figure 2.

[0044] According to one embodiment, which can be combined with other embodiments described herein, a A seal 151, in particular a labyrinth seal, is provided. The use of a seal, in particular a labyrinth seal, at the interface between the gas outlet housing and the heat shield, as shown by way of example in Figure 2, advantageously contributes to the thermal insulation between the gas outlet housing and the mounting receptacle of the heat shield.

[0045] As can be seen from the embodiments described herein, it is advantageous to provide a turbomachine with an improved attachment of the heat shield, so that the thermal insulation properties of the heat shield, in particular in the area of ​​attachment, are improved compared to the prior art. REFERENCE MARK LIST 10 Turbomachine 11 bearing housings 111 Oil room 112 radial outer area of ​​the bearing housing 113 seats 113U Circumferential area of ​​the seat 114 turbine-side bearing housing wall 115 threadless fastener receptacles 116 turbine-side lowering 117 Cool structure 118 Air jacket 12th wave 121 central axis of rotation 13 Rotor 14 Heat shield 141 Fastener receptacle 142 complementary seat of the heat shield 143 Bridge 144 radial outer area of ​​the heat shield 15 Gas outlet housings 151 Seal 16 Fasteners 17 first air-filled insulation space 18 second air-filled insulation space 19 third air-filled isolation room 20 Gas outlet channel x axial direction r radial direction S radial gap R radius of the heat shield Rimin minimum radial extent of the first air-filled insulation space Ri maxmaximum radial extent of the first air-filled insulation space R 2mm minimal radial expansion of the second air-filled Isolation room R 2max maximum radial expansion of the second air-filled insulation space

Claims

CLAIMS 1. Turbomachine (10), comprising: - a shaft (12) mounted in a bearing housing (11) on which a rotor (13) is arranged, - a heat shield (14) which is arranged between the bearing housing (11) and a gas outlet housing (15) of the turbomachine, wherein the heat shield (14) has a radially outer fastening means receptacle (141) in order to fasten the heat shield (14) to the bearing housing (11) by means of a fastening means (16), wherein the fastening means receptacle (141) is arranged between the bearing housing (11) and the gas outlet housing (15), wherein the fastening means receptacle (141) is an axial fastening means receptacle, and wherein the fastening means (16) extends through the axial fastening means receptacle.

2. Turbomachine (10) according to claim 1, wherein a first air-filled insulation space (17) is provided between the fastening means receptacle (141) and the gas outlet housing (15).

3. Turbomachine (10) according to claim 1 or 2, wherein a second air-filled insulation space (18) is provided between a radially outer region (144) of the heat shield (14) and the bearing housing (11).

4. Turbomachine (10) according to claim 3, wherein a maximum radial extent R 2m ax of the second air-filled insulation space (18) from a central axis of rotation (121) of the shaft (12) is less than a maximum radial extension Ri max of the first air-filled isolation room (17).

5. Turbomachine (10) according to one of claims 1 to 4, wherein the Heat shield (14) provides a bearing housing side wall (21) of a gas outlet channel (20) of the turbomachine.

6. Turbomachine (10) according to claim 5, wherein a third air-filled insulation space (19) is provided between the bearing housing-side side wall (21) of the gas outlet channel (20) and the bearing housing (11).

7. Turbomachine (10) according to one of claims 1 to 6, wherein the bearing housing (11) comprises an oil chamber (111), and wherein contact of the fastening means receptacle (11) with the bearing housing (11) takes place in a radially outer region (112) of the bearing housing (11), in which the oil chamber extends completely.

8. Turbomachine (10) according to one of claims 1 to 6, wherein the bearing housing (11) comprises an oil chamber (111), and wherein contact of the fastening means receptacle (141) with the bearing housing (11) takes place in a radially outer region (112) of the bearing housing (11), in which the oil chamber does not extend or only partially extends.

9. Turbomachine (10) according to one of claims 1 to 8, wherein the fastening means 16 extends into a cooling structure 117 arranged in an oil chamber 111 of the bearing housing 11.

10. Turbomachine (10) according to one of claims 1 to 9, wherein a radial gap (S) is present between the fastening means receptacle (141) and the gas outlet housing (15).

11. Turbomachine (10) according to one of claims 1 to 10, wherein the bearing housing (11) has a seat (113), in particular a radial seat, for a complementary seat (142) of the heat shield (14).

12. Turbomachine (10) according to claim 11, wherein the complementary seat (142) of the heat shield (14) is connected to the fastening means receptacle (141) via a substantially radially extending web (143).

13. Turbomachine (10) according to one of claims 1 to 12, wherein at an interface between the gas outlet housing (15) and the Heat shield (14) a seal (151), in particular a labyrinth seal, is provided.

14. Turbomachine (10) according to one of claims 1 to 13, wherein the turbomachine is an axial exhaust gas turbine and the rotor (13) is a turbine wheel, in particular a turbine disk.

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