Flap assembly for turbine of exhaust gas turbocharger

Abstract

The present invention relates to a flap assembly for a turbine of an exhaust gas turbocharger, in particular a flap assembly for a wastegate valve of the turbine, the flap assembly comprising: a main shaft for rotatably supporting the flap assembly in a turbine housing; a lever arm, wherein the lever arm is connected to the main shaft and a flap disk, wherein the flap disk is connected to the lever arm. The flap disk has a flexible portion in a radially outer region of the flap disk, so that when the flap disk is in contact with a flap seat in the turbine housing, elastic and / or plastic deformation of the flexible portion of the flap disk can be caused by applying a closing force to the flap assembly, thereby compensating for thermal deformation, exhaust gas deposits and / or wear of the turbine housing 3.

Description

Technical Field

[0001] The invention relates to a flap assembly for a turbine of an exhaust gas turbocharger and a turbine and an exhaust gas turbocharger having a corresponding flap assembly. Background Art

[0002] Known exhaust gas turbochargers have a turbine with a turbine wheel, which is driven by the exhaust gas flow of the combustion engine. The compressor wheel, which is arranged on a common shaft with the turbine wheel, compresses the fresh air drawn in for the engine, thereby increasing the pressure of the fresh air. As a result, the amount of air or oxygen available to the engine for combustion increases, which in turn increases the power of the combustion engine. Since the turbine wheel is coupled to the compressor wheel, the pressure to be built up always depends on the exhaust gas volume delivered. In certain operating states, it is necessary to reduce or adjust the drive energy acting on the compressor.

[0003] For this purpose, wastegate valves are used in particular, which can release or close a bypass channel or a wastegate channel. The exhaust gas can be guided through the wastegate valve and the bypass pipe and thus guided around the turbine, so that the entire exhaust gas volume no longer acts on the turbine impeller. These wastegate valves are designed in most cases as flap valves actuated by an actuator. For known flap assemblies, the flap disc is fixedly connected to a lever arm, wherein the lever arm is connected to a main shaft, and the main shaft is rotatably supported in the turbine housing. The hot exhaust gas flow causes the turbine to heat up sharply, so that the turbine housing reaches a high temperature. The high temperature causes thermal expansion in the turbine housing. However, since the same temperature is not present everywhere and the wall thickness in the corresponding area of ​​the turbine housing may be different, the degree of thermal expansion is not the same everywhere. This may cause the flap seat of the flap assembly in the turbine housing to deform. In addition, the shape of the flap seat may change due to wear and exhaust gas deposition. Deformation is problematic because deformation can cause leakage, especially for rigid flap assemblies, because the rigid flap disc is no longer placed flat on the flap seat. Increased leakage leads to a loss of performance. Even with excessively high adjustment forces by the actuator, the deformation can only be partially compensated. Summary of the invention

[0004] It is therefore an object of the present invention to provide a flap assembly for a turbine of an exhaust gas turbocharger which is able to compensate for deformations.

[0005] The invention relates to a flap assembly for a turbine according to claim 1 , a turbine according to claim 14 , and an exhaust gas turbocharger according to claim 15 .

[0006] According to the present invention, a valve flap assembly for a turbine of an exhaust gas turbocharger, in particular a valve flap assembly for a wastegate valve of a turbine, comprises: a main shaft, which is used to rotatably support the valve flap assembly in a turbine housing; a lever arm, wherein the lever arm is connected to the main shaft; and a valve flap disk, wherein the valve flap disk is connected to the lever arm. According to the present invention, the valve flap disk has a flexible portion in a radially outer region of the valve flap disk, so that when the valve flap disk is in contact with a valve flap seat in the turbine housing, elastic and / or plastic deformation of the flexible portion of the valve flap disk can be caused by applying a closing force to the valve flap assembly, thereby compensating for thermal deformation, exhaust gas deposition and / or wear of the turbine housing. By the flexible design of an area of ​​the valve flap disk, the valve flap disk can be adapted to the changed shape / position of the valve flap seat under corresponding force loading, wherein the force loading (in order to overcome the clearance caused by thermal deformation, exhaust gas deposition and / or wear of the turbine housing) can be kept small relative to known rigid valve flap assemblies. In addition, the valve flap assembly according to the present invention also enables the valve flap disc to be better located on the valve flap seat and thus achieves better sealing of the wastegate passage. In addition, the valve flap disc that may be caused by the valve flap seat deformation is better avoided from getting stuck in the valve flap seat (so-called "sticking").

[0007] In a design solution, the valve flap disk may also have a rigid portion, wherein the flexible portion surrounds the rigid portion.

[0008] In an embodiment which can be combined with all the embodiments described above, the flap disk can be circular or oval and the flexible portion can be an annular region.

[0009] In a configuration which can be combined with all the configurations described above, the flap disk can have a bottom surface, wherein the bottom surface has a bottom area U A , where the bottom area U A The first sub-area T assigned to the flexible portion F , and a second subarea T assigned to the rigid part S The first sub-area T F In particular, it can be greater than or equal to the bottom area U A 0.2 times, especially greater than or equal to the bottom area U A 0.4 times, particularly preferably greater than or equal to the bottom area U A 0.5 times of.

[0010] In a design which can be combined with all the designs described so far, the valve flap disk has a contact point A on its edge which, in the installed state, first contacts the valve flap seat during the closing process of the valve flap assembly, wherein the lever length L H It can be defined as the contact point A and the second sub-area TS The distance between the geometric centroids and the maximum length (L 最大 ) can be defined as the maximum distance between two points on the edge of the valve disc that are opposite to each other. H With L 最大 The relationship applies to: 0.20≤L H / L 最大 ≤0.95, especially 0.40≤L H / L 最大 ≤0.90. In addition, the flexible length L F It can be defined as the contact point A and the second sub-area T S The distance between the outer edges of F / L H The relationship that applies is: 0.20≤LF / LH≤0.95, especially 0.40≤LF / LH≤0.95.

[0011] In one embodiment which can be combined with all the embodiments described so far, the flap disk has a thickness D in the region of the outer edge of the flexible part. t The entire flexible portion of the valve disc may have a thickness D t Corresponding constant thickness. Alternatively, the flexible part of the valve flap disc can have different thicknesses, especially in the radial direction viewed from the outer edge toward the rigid part. In the radial direction toward the rigid part, the thickness of the flexible part can increase. Alternatively, in the radial direction toward the rigid part, the thickness of the flexible part can decrease.

[0012] In an embodiment that can be combined with all the embodiments described so far, the bottom surface and / or the top surface of the flexible part can be provided with at least one recess. The flexibility of the flexible part can be adapted or increased in a targeted manner by means of the recess(es). The at least one recess can be designed in the form of at least one groove arranged in the circumferential direction. The groove can be a closed groove in particular in the circumferential direction or can extend over at least one sub-area.

[0013] In a design that can be combined with all the designs described so far, at least a portion of the lever arm can be designed to be flexible so that when the flap disk is in contact with the flap seat in the turbine housing, a relative movement of the entire flap disk with respect to the spindle can be achieved by applying a closing force to the flap assembly, thereby compensating for thermal deformations, exhaust gas deposits and / or wear of the turbine housing. It has been found that by combining a flap disk with a flexible region and an at least partially flexible lever arm, on the one hand, a very good sealing effect can be achieved and on the other hand, the stresses in the flap assembly, in particular the lever arm, can be reduced. Lower stresses increase the safety of component failures and the service life of the flap assembly.

[0014] In the case of a design with a flexible lever arm, only one subregion or a plurality of subregions of the lever arm may be designed to be flexible. The flexible subregion or subregions may have a smaller cross-sectional area than the rest of the lever arm.

[0015] In a design that can be combined with all the designs described so far with a flexible lever arm, the lever arm can be designed and arranged relative to the spindle and the flap disk in such a way that the flexible sub-region is substantially subjected to pressure due to the closing force when there is no thermal deformation or wear of the turbine housing or when there is no deposit. Such an arrangement and design of the flexible sub-region has the advantage that the desired effect of the flexible sub-region (i.e. compensation for thermal deformation, deposits or wear) is actually only produced when there is thermal deformation or wear and / or when the flap disk no longer lies completely flat on the flap seat due to other reasons such as deposits. If there is no thermal deformation or wear or when there is no deposit, i.e. when the flap disk lies completely flat on the flap seat, the flexible sub-region is only subjected to pressure, so that there is hardly any relative movement between the flap disk and the spindle. If the flap disk no longer lies completely flat on the flap seat due to thermal deformation, wear or other reasons (e.g. deposits) (leakage occurs), a moment is introduced into the flexible sub-region when a closing force is applied to the flap assembly in the closed position of the flap assembly. This moment causes the relative movement of the valve flap disk relative to the main shaft due to the at least partial flexibility of the lever arm, so that the valve flap disk is placed completely flat on the valve flap seat again. Therefore, a particularly good seal is achieved together with the flexible part of the valve flap disk.

[0016] In a design that can be combined with all the designs described so far with a flexible lever arm, the lever arm can have at least a first lever arm section and a second lever arm section, wherein the end of the second lever arm section is connected to the valve flap disk. The flexible sub-region or regions can be arranged in the region of the second lever arm section and / or the flexible sub-region or regions can be arranged in the region of the first lever arm section. In an alternative design, a large part of the lever arm, in particular the entire lever arm, can be designed to be flexible.

[0017] In a configuration which can be combined with all previously described configurations with a flexible lever arm, the flexible subregion or subregions of the lever arm can have a lower bending stiffness than the rest of the lever arm and / or the spindle.

[0018] In an embodiment that can be combined with all the embodiments described so far with a flexible lever arm, the valve flap disk and / or the lever arm can be dimensioned and have material properties such that when a torque in the range of 0.8 to 20 Nm, preferably in the range of 1.5 to 15 Nm, in particular in the range of 2 to 10 Nm, is introduced into the spindle, an angle α of up to 3° can be compensated. The angle α is defined as the angle between the plane of the valve flap seat and the plane of the bottom surface of the valve flap disk.

[0019] In an embodiment that can be combined with all the embodiments described so far with a flexible lever arm, the valve disc and / or the lever arm can be dimensioned and have material properties such that, at a stress level of between 125 MPa and 350 MPa on the lever arm, the valve disc can achieve a deflection of between 0.10 mm and 0.80 mm, in particular between 0.24 mm and 0.4 mm. The valve disc and / or the lever arm can be dimensioned and have material properties such that, at a stress level of between 150 MPa and 200 MPa on the lever arm, the valve disc can achieve a deflection of between 0.32 mm and 0.36 mm; at a stress level of between 200 MPa and 250 MPa on the lever arm, the valve disc can achieve a deflection of between 0.32 mm and 0.34 mm; at a stress level of between 300 MPa and 350 MPa on the lever arm, the valve disc can achieve a deflection of between 0.10 mm and 0.80 mm, in particular between 0.24 mm and 0.4 mm. The valve disc can achieve an offset between 0.32mm and 0.34mm when a stress level between 300MPa and 350MPa is applied to the lever arm, the valve disc can achieve an offset between 0.28mm and 0.32mm; when a stress level between 250MPa and 300MPa is applied to the lever arm, the valve disc can achieve an offset between 0.38mm and 0.40mm; and when a stress level between 125Mpa and 175Mpa is applied to the lever arm, the valve disc can achieve an offset between 0.26mm and 0.28mm.

[0020] In embodiments which can be combined with all the embodiments described above, the spindle and the lever arm or the lever arm and the flap disk can be designed in one piece, or the spindle, the lever arm and the flap disk can be designed in one piece.

[0021] In a design that can be combined with all the designs described so far, the valve flap disk can be fixedly connected to the lever arm. In particular, the lever arm can be welded to the valve flap disk.

[0022] In an embodiment which can be combined with all the embodiments described above, the flap disk can have a spherical recess on its top side, in which the spherical end of the lever arm can be arranged.

[0023] In one embodiment which can be combined with all of the embodiments described above, the flap disk, the lever arm and / or the spindle are produced as an MIM part.

[0024] The invention further comprises a turbine for an exhaust gas turbocharger having a turbine housing and a wastegate valve which is suitable for conducting exhaust gas away from a turbine wheel of the turbine. The wastegate valve comprises a flap assembly according to any of the above-described embodiments.

[0025] In one embodiment of the turbine, the turbine housing can have a bushing bore, in which a bushing is arranged, wherein a main shaft of the flap arrangement can be rotatably mounted in the bushing.

[0026] The present invention also includes an exhaust gas turbocharger having a turbine according to any one of the above-mentioned embodiments.

[0027] Further details and features of the invention are described below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 An isometric view in partial section showing an embodiment of a turbocharger according to the invention;

[0029] Figure 2 An isometric view showing a first embodiment of a valve flap assembly according to the present invention;

[0030] Figure 3 Show Figure 2 An enlarged side view of the valve disc of the embodiment of FIG.

[0031] Figure 4a An isometric view in partial section showing a valve flap disc of a second embodiment of a valve flap assembly according to the present invention;

[0032] Figure 4b Show Figure 4a A cross-sectional view of the valve disc in FIG.

[0033] Figure 4c A cross-sectional view showing a valve flap disc of a third embodiment of a valve flap assembly according to the present invention;

[0034] Figure 5a A view showing a valve flap disc of a fourth embodiment of a valve flap assembly according to the present invention;

[0035] Figure 5b A view showing a valve flap disk of a fifth embodiment of a valve flap assembly according to the present invention;

[0036] Figure 6 A side view showing a sixth embodiment of a valve flap assembly according to the present invention. DETAILED DESCRIPTION

[0037] An exemplary embodiment of a flap assembly 10 according to the invention as well as a turbine 2 having such a flap assembly 10 and a corresponding exhaust gas turbocharger 1 are described below with reference to the drawings.

[0038] Figure 1 An exhaust gas turbocharger 1 is shown, which can be equipped with the embodiment described below of the valve flap assembly 10 according to the invention. The exhaust gas turbocharger 1 comprises a turbine 2, which has a turbine housing 3 and a wastegate valve, which is suitable for conducting exhaust gas away from a turbine wheel 4 of the turbine 2. In this case, the wastegate valve comprises the valve flap assembly 10 according to the invention. The turbine housing 3 also has a bushing bore, in which a bushing can be arranged, wherein the valve flap assembly 10 is then rotatably mounted in the bushing.

[0039] Reference Figures 2 to 6 The valve flap assembly 10 according to the present invention will be described below. Figure 2 As can be seen in the figure, the valve flap assembly 10 includes a main shaft 100 (which is used to rotatably support the valve flap assembly 10 in the turbine housing 3) and a lever arm 200. The main shaft 100 defines a rotation axis 400. The lever arm 200 is connected to the main shaft 100. In addition, the valve flap assembly also includes a valve flap disc 300, wherein the valve flap disc 300 is connected to the lever arm 200. According to the present invention, the valve flap disc 300 has a flexible portion 330 in the radially outer region of the valve flap disc 300. The flexible portion 330 of the valve flap disc 300 allows the valve flap disc 300 to be rotatably supported when the valve flap disc 300 is in contact with the valve flap seat 500 (see Figure 6 ) when in contact, applying a closing force to the valve flap assembly 10 can cause elastic and / or plastic deformation of the flexible portion 330 of the valve flap disc 300, thereby compensating for thermal deformation, exhaust gas deposition and / or wear of the turbine housing 3.

[0040] During the elastic and / or plastic deformation process, the flexible part 330 of the valve flap disc 300 is deformed to adapt to the deformed or slightly displaced valve flap seat 500. For example, the valve flap seat 500 may be elastically and plastically changed due to thermal load compared to the original shape and position of the valve flap seat. In addition, the shape of the valve flap seat 500 may also change due to wear and exhaust gas deposits. Through the flexible design of a part 330 of the valve flap disc 300, the valve flap disc can be adapted to the changed shape / position of the valve flap seat 500 under corresponding force loading, wherein the force loading (in order to overcome the clearance caused by thermal deformation of the turbine housing, exhaust gas deposits and / or wear) can be advantageously kept small compared to known rigid valve flap assemblies. In addition, the valve flap assembly 10 according to the present invention also enables the valve flap disc 300 to be better located on the valve flap seat 500 and thereby achieves a better sealing of the wastegate channel to be closed by the valve flap assembly 10. In addition, the valve flap disc 300 can be better prevented from getting stuck in the valve flap seat 500 (so-called “sticking”) which may be caused by deformation of the valve flap seat 500 .

[0041] As in Figures 2 to 4c As can be easily seen in the figure, the valve flap disk 300 also has a rigid part 335, wherein the flexible part 330 surrounds the rigid part 335. The rigid part 335 includes or corresponds to the receiving area 340 (see Figure 2 ), in which receiving area the lever arm 200 is connected to the valve flap disk 300 .

[0042] like Figures 2 to 4c As shown, the valve disc 300 can be circular. Alternatively, the valve disc can also be elliptical. Here, the flexible portion 330 is designed as an annular area 330. However, the valve disc 300 is not limited to a specific shape, but can have any reasonable geometric shape adapted to the corresponding application. As shown, the valve disc can be, for example, circular or elliptical. In these cases, the flexible area 330 can also be designed as circular or elliptical. For example, in Figure 5b An alternative shape of a flap disk 300 is shown.

[0043] Reference Figures 4a to 5b The valve disc 300 has a bottom surface 302, wherein the bottom surface 302 is the surface of the valve disc 300 that is shown in the direction toward the valve disc seat 500. The bottom surface 302 defines a bottom area U A . Bottom area U A It can be divided into a first sub-area T assigned to the flexible portion 330 F , and the second sub-area T assigned to the rigid portion 335 S (See, for example, Figure 5a and 5b ). The first sub-area T FCan be greater than or equal to the bottom area U A 0.2 times, especially greater than or equal to the bottom area U A 0.4 times, particularly preferably greater than or equal to the bottom area U A In other words: the second sub-area T S The bottom area U corresponding to the rigid portion 335 of the valve disc 300 is directed toward the valve disc 300. A Then, the first subarea T F Corresponding to the remaining bottom area U A , that is, the bottom area U A Subtract the second subarea T S Here, it can be T F ≥0.2*U A , especially T F ≥0.4*U A , which may be T F ≥0.5*U A . Using a different expression again, for the second sub-area T S With the bottom area U A The relationship can be given as: 0.01≤T S / U A ≤0.8, preferably 0.1≤T S / U A ≤0.6, particularly preferably 0.2≤T S / U A ≤0.5.

[0044] Reference Figure 3 , 5a 6 show that the valve disc 300 has a contact point A at the edge of the valve disc 300, which first contacts the valve disc seat 500 during the closing process of the valve disc assembly 10 in the installed state (see Figure 6 ). Reference Figure 5a and 5b , the lever length L of the valve disc 300 can be adjusted via the contact point A H Defined as the contact point A and the second sub-area T S In addition, the maximum length L of the valve disc 300 can also be 最大 It is defined as the maximum distance between two opposite points on the edge of the valve flap disk 300 .

[0045] exist Figure 4a and 5a The following example is shown in FIG. 1 , in which the valve disc 300 is designed to be circular with a diameter of D; and the rigid part 335 is designed to be circular with a diameter of d. The second sub-area T of the circle thus generated S Centrally (and concentrically) arranged on the bottom area UA This corresponds to the lever arm 200 being arranged centrally on the valve flap disk 300. In such a design, the lever length L H Equal to the radius R of the valve disc 300 (see Figure 5a ). At lever length L 最大 For the circular example, the following applies: lever length L M Corresponding to the diameter D of the valve flap disk 300 . Figure 5b An alternative embodiment is shown.

[0046] For all designs, the following applies in particular to L H With L 最大 Relationship:

[0047] 0.20≤L H / L 最大 ≤0.95; especially 0.40≤L H / L 最大 ≤0.90.

[0048] See also Figure 3 , it is also possible to adjust the lever length L of the valve disc 300 F Defined as the contact point A and the second sub-area T S The following applies in particular to L F / L H Relationship:

[0049] 0.20≤LF / LH≤0.95, especially 0.40≤LF / LH≤0.90.

[0050] The flap disk 300 has a thickness D in the region of the outer edge of the flexible portion 330 . t (See Figure 3 The entire flexible portion 330 of the valve flap disc 300 may have a thickness D t For the corresponding constant thickness, see also Figure 3 Alternatively, the flexible portion 330 of the valve flap disc 300 may also have different thicknesses, in particular in the radial direction viewed from the outer edge toward the rigid portion 335. In the radial direction toward the rigid portion 335, the thickness of the flexible portion 330 may increase. Alternatively, in the radial direction toward the rigid portion 335, the thickness of the flexible portion 330 may decrease. For example, the thickness of the flexible portion 330 may increase (at least in sections) up to at least 1.1*D t Alternatively, the thickness of the flexible portion 330 can be reduced (at least in sections) up to 0.9*D at the latest before the thickness increases again in the transition region to the rigid portion 335. tThe boundary between the flexible portion 330 and the rigid portion 335 (more specifically, the transition area from the flexible portion 330 to the rigid portion 335 of the valve flap disc 300) can be defined as the thickness of the valve flap disc 300 being greater than about 1.2*D t In other words, the thickness of the flexible portion 330 is less than 1.2*D t In an exemplary example, the flexible region 330 may have the following characteristics: its thickness is less than or equal to 8 mm. The thickness of the flexible region 330 may be in particular in the range of 1 mm to 8 mm, in particular 1 mm to 5 mm, preferably 1 mm to 4 mm.

[0051] like Figures 4a to 4c As shown, at least one recess 336 can be provided on the bottom surface 302 and / or the top surface 314 of the flexible portion 330 of the valve disc 300. The flexibility of the flexible portion 330 can be adapted or improved in a targeted manner through the recess (these) 336. The at least one recess 336 can be designed in the form of at least one groove arranged in the circumferential direction. The groove can be a closed groove in particular along the circumferential direction, or can extend over at least one sub-region. For example, one or more grooves can also be provided in a segmented distribution, or a plurality of grooves can also be provided in a radially offset manner, and these grooves extend over the entire circumference or only extend over a sub-region / segment of the circumference.

[0052] See especially below Figure 2 and 6 . In addition to (or in lieu of) the valve flap disc 300 having the flexible portion 330, a portion of the lever arm 200 of the valve flap assembly 10 can also be designed flexibly so that when the valve flap disc 300 is in contact with the valve flap seat 500 in the turbine housing 3, a relative movement of the entire valve flap disc 300 relative to the main shaft 100 can be achieved by applying a closing force to the valve flap assembly 10. This in turn makes it possible to compensate for thermal deformations, exhaust gas deposits and / or wear of the turbine housing 3. By designing the valve flap assembly 10 with a flexible lever arm 200, when the valve flap assembly 10 is subjected to a corresponding force load in the closed state, the lever arm 200 is slightly elastically and / or plastically deformed, for example bent. In particular, this can also better compensate for differences in thermal deformations of the valve flap seat 500 that occur during the operation of the turbocharger. This in turn allows the valve flap disc 300 to be better located on the valve flap seat 500 and thereby achieve better sealing of the wastegate channel. The same applies to compensating for (irregular) wear and / or exhaust gas deposits that may cause leakage. Better sealing equates to less leakage, which in turn can lead to a reduction in the closing force applied to the valve flap assembly 10 compared to known rigid valve flap assemblies. In addition, the risk of the valve flap assembly 10 getting stuck ("sticking") is reduced.

[0053] Furthermore, it has been found that the combination of a flap disk 300 having a flexible region 330 with an at least partially flexible lever arm 200 can reduce stresses in the flap assembly 10 , in particular in the lever arm 200 . Lower stresses increase component failure safety and the service life of the flap assembly 10 .

[0054] According to the design of the valve flap assembly, one or more sub-areas 220 of the lever arm 200 can be designed to be flexible. For example, the flexible sub-area 220 can have a smaller cross-sectional area than the rest of the lever arm 200. The lever arm 300 can be designed and arranged relative to the main shaft 100 and the valve flap disk 300 in particular so that when there is no thermal deformation or wear of the turbine housing 3 or there is no deposit, the flexible sub-area 220 is essentially under pressure due to the closing force. This arrangement and design of the flexible sub-area 220 has the following advantages: the desired effect of the flexible sub-area 220 (i.e. compensation for thermal deformation) is actually only produced when thermal deformation or wear occurs and / or the valve flap disk 300 is no longer completely flat on the valve flap seat 500 due to other reasons such as deposits. If no thermal deformation or wear or deposits are present (i.e. if the valve flap disk 300 lies completely flat on the valve flap seat 500), the flexible sub-region(s) 220 are only subjected to pressure, so that there is hardly any relative movement between the valve flap disk 300 and the spindle 100. If the valve flap disk 300 no longer lies completely flat on the valve flap seat 500 due to thermal deformation, wear or other reasons (e.g. deposits) (leakage occurs), a moment is introduced into the flexible sub-region(s) 220 when a closing force is applied to the valve flap assembly 10 in the closed position of the valve flap assembly 10. This moment leads to a relative movement of the valve flap disk 300 with respect to the spindle due to the at least partial flexibility of the lever arm 200, so that the valve flap disk 300 lies completely flat on the valve flap seat 500 again. This achieves a particularly good seal.

[0055] exist Figure 2 and 6 It is shown that the lever arm 200 can have at least a first lever arm section 230 and a second lever arm section 240, wherein the end 210 of the second lever arm section 240 is connected to the valve flap disk 300. The first lever arm section 230 and the second lever arm section 240 can enclose an angle 250 of, for example, between 20° and 80°, in particular between 30° and 70°, preferably between 40° and 60°. Figure 2In the embodiment shown in , the second lever arm section 240 extends substantially perpendicularly to the top surface 310 of the valve flap disk 300. The sub-region or sub-regions 220 can be arranged in the region of the second lever arm section 240. Alternatively or additionally, the flexible sub-region 220 can be arranged in the region of the first lever arm section 230. In an alternative design, most of the lever arm 200, in particular the entire lever arm 200, can be designed to be flexible.

[0056] In order to achieve flexibility in the lever arm 200 , the flexible subregion or subregions 220 of the lever arm 200 have a lower bending stiffness than the rest of the lever arm 200 and / or than the spindle 100 .

[0057] refer to Figure 6 An example is shown in which thermal deformation, wear and / or exhaust gas deposits cause the valve disc 300 to be unevenly placed on the valve disc seat 500. The contact point A has contacted the valve disc seat 500, but the valve disc 300 is tilted and therefore a gap is left between the valve disc 300 and the valve disc seat 500. Here, Figure 6 : In the figure, it is shown by way of example how forces and stresses act on the flexible sub-region 220 of the lever arm 200 in such a case, thereby causing a corresponding adaptation of the position of the valve flap disk 300 and thus enabling the entire valve flap disk 300 to be placed on the valve flap seat 500. The closing force F generated by the moment T due to the rotation of the spindle 100 acts on the lever arm 200 with the flexible sub-region 220. This force has a vector component F Z and F Y When the force F acts on the flexible sub-region 220 of the lever arm 200, compressive stress (“Compression”) and tensile stress (“Tension”) are thus generated in the illustrated range of the flexible sub-region 220. Due to these tensile and compressive stresses, the lever arm 200 can be deformed in its flexible sub-region 220 in such a way that the tilted position of the valve flap disk 300 relative to the valve flap seat 500 can be compensated, so that the valve flap disk 300 is placed (almost) completely on the valve flap seat 500 again and the desired sealing effect is achieved.

[0058] exist Figure 6, which is defined as the angle between the plane of the valve flap seat 500 and the plane of the bottom surface 302 of the valve flap disk 300. Since the valve flap disk 300 lies essentially flat on the valve flap seat 500 in the closed state, the angle α is approximately 0° in the installed state in the new state of the valve flap assembly 10. If thermal deformation, exhaust gas deposits or wear occur, the position and / or shape of the valve flap seat 500 changes slightly. Then, in the closed position of the valve flap assembly 10 (no pressing force is applied to the valve flap disk 300), the planes in which the valve flap seat 500 and the valve flap disk 300 are each arranged no longer coincide, so that an angle α of greater than 0° is generated between the two planes and the valve flap disk 300 is therefore no longer placed sealingly on the valve flap seat 500.

[0059] In the embodiment, the flap disk 300 alone or the lever arm 200 alone or the combination of the flap disk 300 and the lever arm 200 can now be dimensioned / shaped and have material properties such that an angle α of up to 3° can be compensated when a torque in the range of 0.8 to 20 Nm, preferably in the range of 1.5 to 15 Nm, in particular in the range of 2 to 10 Nm is applied to the spindle 100. This means that the angle α can be compensated by the flexible design of the flap disk 300 and / or the lever arm 200, so that a better sealing of the wastegate channel is achieved.

[0060] Here, the deformation or displacement of the flexible portion 330 of the valve flap disk 300 and / or the flexible sub-region or sub-regions 220 of the lever arm 200 can be plastic or elastic. Since the displacement or change of the valve flap seat 500 can also be plastic due to thermal effects and / or wear, in particular a plastic change of the valve flap disk 300 and / or the lever arm 200 can also be advantageous, because this can achieve a permanently improved sealing effect.

[0061] The flexibility of the valve flap disk 300, the lever arm 200 and / or the combination of the valve flap disk 300 and the lever arm 200 can also be defined in the following manner. The valve flap disk 300 and / or the lever arm 200 can be dimensioned and have material properties such that, when a stress level of between 125 MPa and 350 MPa is applied to the lever arm 200, the valve flap disk 300 can achieve a deflection of between 0.10 mm and 0.80 mm, in particular between 0.24 mm and 0.4 mm. The valve disc 300 and / or the lever arm 200 can be dimensioned and have material properties such that when a stress level between 150 MPa and 200 MPa is applied to the lever arm 200, the valve disc 300 can achieve a deflection between 0.32 mm and 0.36 mm; when a stress level between 200 MPa and 250 MPa is applied to the lever arm 200, the valve disc 300 can achieve a deflection between 0.32 mm and 0.34 mm; when a stress level between 300 MPa and 350 MPa is applied to the lever arm 200, the valve disc 300 can achieve a deflection between 0.32 mm and 0.34 mm. When a stress level between 300MPa and 350MPa is applied to the lever arm 200, the valve flap disc 300 can achieve an offset between 0.28mm and 0.32mm; when a stress level between 250MPa and 300MPa is applied to the lever arm 200, the valve flap disc 300 can achieve an offset between 0.38mm and 0.40mm; and when a stress level between 125MPa and 175MPa is applied to the lever arm 200, the valve flap disc 300 can achieve an offset between 0.26mm and 0.28mm.

[0062] In addition to the partially flexible valve flap disc 300 and / or the (partially) flexible lever arm 200, the main shaft 100 can also be designed to have a certain flexibility. For example, the middle part of the main shaft 100 can be more flexible than the two edge areas of the main shaft 100 (seen in the axial direction). For example, this can be achieved by reducing the main shaft diameter in the middle part of the main shaft 100. Such measures can further improve the sealing effect of the valve flap assembly 10.

[0063] A flexible flap assembly 10 is described above, wherein a portion 220 of the lever arm 200 or the entire lever arm 200 can be designed to be flexible, a portion 330 of the flap disc 300 can be designed to be flexible, and / or a portion of the spindle 100 can be designed to be flexible. The desired flexibility of the flap assembly 10 can be achieved by one or more of the measures described above. If elastic and / or plastic deformation (including creep elongation) is achieved at a system stiffness of the flap assembly 10 of a maximum of 2500 N / mm and an average material temperature of approximately 850° C., a flexible flap assembly 10 in the sense of the present invention can be considered (when the spindle 100, the lever arm 200 and the flap disc 300 act together). In this case, the system stiffness refers to the system consisting of the spindle 100, the lever arm 200 and the flap disc 300, which are fixedly / rigidly connected to each other or designed as a single piece. In this case, the stiffness is defined as F / ΔL. F is the force applied to the outer edge of the flap disk 300 in the test structure for determining the rigidity of the system, applied at the contact point A. Here, if the spindle 100 is fixed in a fixed position, perpendicular to the bottom area U A ΔL is the (elastic and / or plastic) deformation of the system caused by the force acting on the valve flap disk 300 .

[0064] The main shaft 100 and the lever arm 200 can be designed in one piece. "In one piece" means that the main shaft 100 and the lever arm 200 are made as a common (integral) component (for example as a casting). As an alternative, the same applies to the lever arm 200 and the valve disc 300, which can also be designed in one piece. As another alternative, the main shaft 100, the lever arm 200 and the valve disc 300 can also be designed in one piece. That is to say, a single component includes the main shaft 100, the lever arm 200 and the valve disc 300 in an integral manner.

[0065] In all designs, the valve disc 300 is fixedly connected to the lever arm 200. In particular, the lever arm 200 can be welded to the valve disc 300. For example, the valve disc 300 can have a spherical recess 312 on its top surface 310, in which the spherical end 210 of the lever arm 200 can be arranged (see Figure 6 This design makes it easy to install the valve flap assembly 10 and to align and connect the lever arm 200 and the valve flap plate 300 by means of a welding connection.

[0066] The valve disc 300, the lever arm 200 and / or the main shaft 100 can be manufactured as a metal injection molding (MIM) part. The main shaft 100, the lever arm 200 and the valve disc 300 can be designed as independent MIM parts respectively, and then they are connected to each other accordingly. Alternatively, the main shaft 100 and the lever arm 200, the lever arm 200 and the valve disc 300, or the main shaft 100, the lever arm 200 and the valve disc 300 can be manufactured as an integral MIM part.

[0067] “Independent of the production of the unit consisting of the spindle 100, the lever arm 200 and the valve flap disk 300” means that the lever arm 200 and the valve flap disk 300 are rigidly connected to each other in their connection area. In other words, in this connection area arranged in the rigid part 335, there is hardly any relative movement between the lever arm 200 and the valve flap disk 300 due to deformation or the like.

[0068] As already described at the outset, the invention also includes a turbine 2 for an exhaust gas turbocharger 1, which has a turbine housing 3 and a wastegate valve, which is suitable for guiding exhaust gas away from a turbine wheel 4 of the turbine 2. The wastegate valve includes a flap assembly 10 according to any of the above-described embodiments. The invention also includes an exhaust gas turbocharger 1 having such a turbine 2.

[0069] Although the present invention is described above and defined in the appended claims, it should be understood that the invention may alternatively be defined corresponding to the following embodiments:

[0070] The valve flap assembly of the turbine of an exhaust gas turbocharger, in particular the valve flap assembly of the wastegate valve of the turbine, comprises:

[0071] a main shaft for rotatably supporting the valve flap assembly in a turbine housing;

[0072] a lever arm, wherein the lever arm is coupled to the spindle; and

[0073] a valve flap disc, wherein the valve flap disc is coupled to the lever arm;

[0074] It is characterized in that the valve flap disc has a flexible portion in the radially outer area of ​​the valve flap disc, so that when the valve flap disc is in contact with the valve flap seat in the turbine housing, elastic and / or plastic deformation of the flexible portion of the valve flap disc can be caused by applying a closing force to the valve flap assembly, thereby compensating for thermal deformation, exhaust gas deposition and / or wear of the turbine housing.

[0075] Preferably, it is provided that the flap disk also has a rigid part, wherein the flexible part surrounds the rigid part.

[0076] Preferably, provision is made for the flap disk to be circular or oval and for the flexible section to be an annular region.

[0077] Preferably, it is provided that the flap disk has a bottom surface, wherein the bottom surface has a bottom area, wherein the bottom area includes a first subarea assigned to the flexible part and a second subarea assigned to the rigid part.

[0078] It is preferably provided that the first subarea is greater than or equal to 0.2 times the bottom area, in particular greater than or equal to the bottom area (U A ), particularly preferably greater than or equal to the bottom area (U A ) is 0.5 times.

[0079] Preferably, the valve flap disk (300) has a contact point (A) on the edge of the valve flap disk (300), which first contacts the valve flap seat (500) during the closing process of the valve flap assembly (10) in the installed state, wherein the lever length (L H ) is defined as the area between the contact point (A) and the second sub-area (T S ), and

[0080] Maximum length (L 最大 ) is defined as the maximum distance between two opposing points on the edge of the valve flap disc (300).

[0081] The preferred rule is that for L H With L 最大 The relationship that applies is:

[0082] 0.20≤L H / L 最大 ≤0.95, especially 0.40≤L H / L 最大 ≤0.90.

[0083] Preferably, it is provided that the flexible length (L F ) is defined as the contact point (A) and the second sub-area (T S ) between the outer edges, where L F / L H The relationship that applies is:

[0084] 0.20≤L F / L H ≤0.95, especially 0.40≤L F / L H ≤0.90.

[0085] Preferably, it is provided that the flap disk (300) has a thickness (D t ).

[0086] Preferably, the entire flexible portion (330) of the valve flap disc (300) has a thickness (D t ) corresponds to a constant thickness.

[0087] Preferably, provision is made for the flexible portion (330) of the flap disk (300) to have a different thickness, in particular in a radial direction viewed from the outer edge toward the rigid portion (335).

[0088] It is preferably provided that the thickness of the flexible portion (330) increases in the radial direction toward the rigid portion (335); or it is characterized in that the thickness of the flexible portion (330) decreases in the radial direction toward the rigid portion (335).

[0089] Preferably, it is provided that at least one recess (336) is provided on the bottom surface (302) and / or the top surface (314) of the flexible portion (330).

[0090] Preferably, it is provided that the at least one recess (336) is designed in the form of at least one groove arranged in the circumferential direction, wherein the groove is a closed groove in the circumferential direction or extends over at least one partial region.

[0091] It is preferably provided that at least a portion of the lever arm (200) is flexibly designed so that when the valve flap disk (300) is in contact with the valve flap seat (500) in the turbine housing (3), relative movement of the entire valve flap disk (300) relative to the main shaft (100) can be achieved by applying a closing force to the valve flap assembly (10), thereby compensating for thermal deformation, exhaust gas deposits and / or wear of the turbine housing (3).

[0092] It is preferably provided that only one or more subregions (220) of the lever arm (200) are designed to be flexible.

[0093] It is preferably provided that the flexible subregion (220) has a reduced cross-sectional area compared to the rest of the lever arm (200).

[0094] Preferably, the lever arm (200) is designed and arranged relative to the main shaft (100) and the valve flap disk (300) such that the flexible sub-region (220) is substantially subjected to pressure due to the closing force when no thermal deformation or wear of the turbine housing (3) occurs or when no exhaust gas deposits are present.

[0095] Preferably, it is provided that the lever arm (200) has at least a first lever arm section (230) and a second lever arm section (240), wherein an end (210) of the second lever arm section (240) is connected to the flap disk (300).

[0096] It is preferably provided that the flexible subregion(s) (220) are arranged in the region of the second lever arm section (240) and / or that the flexible subregion(s) (220) are arranged in the region of the first lever arm section (230).

[0097] It is preferably provided that a majority of the lever arm (200), in particular the entire lever arm (200), is designed to be flexible.

[0098] It is preferably provided that the flexible subregion(s) (220) of the lever arm (200) has a lower bending stiffness than the rest of the lever arm (200) and / or the spindle (100).

[0099] It is preferably provided that the valve flap disk (300) and / or the lever arm (200) if related to embodiment 15 is dimensioned and has the following material properties so that when a torque in the range of 0.8 to 20 Nm, preferably in the range of 1.5 to 15 Nm, in particular in the range of 2 to 10 Nm, is introduced into the spindle (100), an angle (α) of up to 3° can be compensated, wherein the angle (α) is defined as the angle between the plane of the valve flap seat (500) and the plane of the bottom surface (302) of the valve flap disk (300).

[0100] It is preferably provided that the valve flap disk (300) and / or the lever arm (200) if related to embodiment 15, are dimensioned as follows and have the following material properties so that when a stress level between 125 MPa and 350 MPa is applied to the lever arm (200), the valve flap disk (300) can achieve a displacement between 0.10 mm and 0.80 mm, in particular between 0.24 mm and 0.4 mm.

[0101] It is preferably provided that the valve flap disc (300) and / or the lever arm (200) if related to embodiment 15 is dimensioned in the following manner and has the following material properties, so that when a stress level between 150 MPa and 200 MPa is applied to the lever arm (200), the valve flap disc (300) can achieve a displacement between 0.32 mm and 0.36 mm; when a stress level between 200 MPa and 250 MPa is applied to the lever arm (200), the valve flap disc (300) can achieve a displacement between 0.32 mm and 0.34 mm; when a stress level between 300 MPa and 350 MPa is applied to the lever arm (200), the valve flap disc (300) can achieve a displacement between 0.32 mm and 0.34 mm; The disc (300) can achieve an offset between 0.32 mm and 0.34 mm; when a stress level between 300 MPa and 350 MPa is applied to the lever arm (200), the valve flap disc (300) can achieve an offset between 0.28 mm and 0.32 mm; when a stress level between 250 MPa and 300 MPa is applied to the lever arm (200), the valve flap disc (300) can achieve an offset between 0.38 mm and 0.40 mm; and when a stress level between 125 MPa and 175 MPa is applied to the lever arm (200), the valve flap disc (300) can achieve an offset between 0.26 mm and 0.28 mm.

[0102] Preferably, the main shaft (100) and the lever arm (200) are designed as a single piece, or the lever arm (200) and the valve flap disk (300) are designed as a single piece, or the main shaft (100), the lever arm (200) and the valve flap disk (300) are designed as a single piece.

[0103] Preferably, it is provided that the valve plate (300) is fixedly connected to the lever arm (200), and is particularly characterized in that the lever arm (200) and the valve plate (300) are welded.

[0104] Preferably, it is provided that the flap disk (300) has a spherical recess (312) on its upper side (310), in which the spherical end (210) of the lever arm (200) is arranged.

[0105] Preferably, it is provided that the flap disk (300), the lever arm (200) and / or the spindle (100) are manufactured as MIM parts.

[0106] A turbine (2) for an exhaust gas turbocharger (1) according to the invention comprises:

[0107] a turbine housing (3); and

[0108] a wastegate valve adapted to direct exhaust gas away from a turbine wheel (4) of the turbine;

[0109] Characterized in that the wastegate valve comprises a valve flap assembly (10) according to any one of the aforementioned embodiments.

[0110] It is preferably provided that the turbine housing has a bushing bore, in which a bushing is arranged, wherein the main shaft of the flap component is rotatably mounted in the bushing.

[0111] The invention relates to an exhaust gas turbocharger having a turbine according to the above.

Claims

1. A flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1), the flap assembly comprising: A main shaft (100) for rotatably supporting the valve flap assembly (10) in a turbine housing (3), the turbine housing having a bushing hole; a lever arm (200), wherein the lever arm (200) is coupled to the spindle (100); and A valve flap disc (300), wherein the valve flap disc (300) is connected to the lever arm (200); The valve flap disc (300) has a flexible portion (330) in a radially outer region of the valve flap disc (300), so that when the valve flap disc (300) is in contact with the valve flap seat (500) in the turbine housing (3), elastic and / or plastic deformation of the flexible portion (330) of the valve flap disc (300) can be caused by applying a closing force to the valve flap assembly (10), thereby compensating for thermal deformation, exhaust gas deposition and / or wear of the turbine housing (3), and the valve flap disc (300) also has a rigid portion (335), wherein: The flexible portion (330) surrounds the rigid portion (335), and the valve disc (300) has a bottom surface (302), wherein the bottom surface (302) has a bottom area (U A ), and the bottom area (U A ) includes a first sub-area (T F ) and a second sub-area (T S ), The invention is characterized in that the valve disc (300) has a contact point (A) on the edge of the valve disc (300), and in the installed state, during the closing process of the valve disc assembly (10), the contact point first contacts the valve disc seat (500), wherein the lever length (L H ) is defined as the area between the contact point (A) and the second sub-area (T S ) is the distance between the geometric center of gravity (C) and the maximum length (L 最大 ) is defined as the maximum distance between two opposing points on the edge of the valve disc (300), and For L H With L 最大 The relationship that applies is: 0.20 ≤ L H / L 最大 ≤ 0.

95.

2. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 1, characterized in that: The first sub-area (T F ) is greater than or equal to the bottom area (U A ) is 0.2 times.

3. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 2, characterized in that: The first sub-area (T F ) is greater than or equal to the bottom area (U A ) is 0.4 times.

4. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 3, characterized in that: The first sub-area (T F ) is greater than or equal to the bottom area (U A ) is 0.5 times.

5. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 1, characterized in that: For L H With L 最大 The relationship that applies is: 0.40 ≤ L H / L 最大 ≤ 0.

90.

6. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 1, characterized in that: Flexible length (L F ) is defined as the contact point (A) and the second sub-area (T S ) between the outer edges, where L F / L H The relationship that applies is: 0.20 ≤ L F / L H ≤ 0.

95.

7. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 6, characterized in that: For L F / L H The relationship that applies is: 0.40 ≤ L F / L H ≤ 0.

90.

8. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 1, characterized in that: At least one notch (336) is provided on the bottom surface (302) and / or the top surface (314) of the flexible portion (330).

9. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 1, characterized in that: At least a portion of the lever arm (200) is flexibly designed so that when the valve flap disc (300) is in contact with the valve flap seat (500) in the turbine housing (3), a closing force is applied to the valve flap assembly (10) to enable relative movement of the entire valve flap disc (300) relative to the main shaft (100), thereby compensating for thermal deformation, exhaust gas deposition and / or wear of the turbine housing (3).

10. The flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 9, characterized in that: Only one or more subregions of the lever arm (200) are designed as flexible subregions (220).

11. The flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 10, characterized in that: The lever arm (200) is designed and arranged relative to the main shaft (100) and the flap disk (300) in such a way that the flexible sub-region (220) is substantially subjected to pressure due to the closing force when there is no thermal deformation or wear of the turbine housing (3) or when there are no exhaust gas deposits.

12. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 10 or claim 11, characterized in that: The lever arm (200) comprises at least a first lever arm section (230) and a second lever arm section (240), wherein an end (210) of the second lever arm section (240) is connected to the valve flap disk (300).

13. The flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 12, characterized in that: The flexible subregion (220) is arranged in the region of the second lever arm section (240) and / or the flexible subregion (220) is arranged in the region of the first lever arm section (230).

14. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 9, characterized in that: A large portion of the lever arm (200) is designed to be flexible.

15. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 9, characterized in that: The entire lever arm (200) is designed to be flexible.

16. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 1, characterized in that The valve flap disk (300) is dimensioned and has material properties such that when a torque in the range of 0.8 to 20 Nm is introduced into the spindle (100), an angle (α) of up to 3° can be compensated, wherein the angle (α) is defined as the angle between the plane of the valve flap seat (500) and the plane of the bottom surface (302) of the valve flap disk (300).

17. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 9, characterized in that: The lever arm (200) is dimensioned and has material properties such that when a torque in the range of 0.8 to 20 Nm is introduced into the spindle (100), an angle (α) of up to 3° can be compensated, wherein the angle (α) is defined as the angle between the plane of the valve flap seat (500) and the plane of the bottom surface (302) of the valve flap disk (300).

18. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 9, characterized in that: The valve flap disk (300) and the lever arm (200) are dimensioned and have material properties such that when a torque in the range of 0.8 to 20 Nm is introduced into the spindle (100), an angle (α) of up to 3° can be compensated, wherein the angle (α) is defined as the angle between the plane of the valve flap seat (500) and the plane of the bottom surface (302) of the valve flap disk (300).

19. The valve flap assembly (10) for a turbine (2) of an exhaust gas turbocharger (1) according to claim 1, characterized in that: The valve flap assembly is a valve flap assembly for a wastegate valve of the turbine (2).

20. A turbine (2) for an exhaust gas turbocharger (1), the turbine comprising: a turbine housing (3); and a wastegate valve adapted to direct exhaust gas away from a turbine wheel (4) of the turbine; It is characterized in that The wastegate valve comprises a flap assembly (10) according to any one of the preceding claims 1 to 19.

21. An exhaust gas turbocharger (1), characterized in that: The exhaust gas turbocharger has a turbine (2) according to claim 20.

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