DE102015219773A1 - Turbomachine and internal combustion engine - Google Patents

Abstract

The invention relates to a turbomachine (100) having a compressor (110) and a turbine (120), wherein - a turbine wheel (20) of the turbine (120) and a compressor wheel of the compressor (110) are mounted on a common turbocharger shaft (140) in which - the turbocharger shaft (140) is rotatably supported by a bearing (130), in particular wherein the bearing (130) has a bearing assembly rotatably supporting the turbocharger shaft in a bearing housing, and - the turbine wheel (142, 20) is housed in a turbine chamber (10 ) of a turbine housing (30) of the turbine (120) is rotatably arranged, wherein a bearing-side back (21.A, 21.B) of the turbine wheel (20) an inner side (31.A, 31.B) of a turbine housing wall (31) via a Radrückenraum (13) in the turbine chamber (10) faces, in the Radrückenraum a gas, in particular exhaust gas, circumferentially around an axial direction (z) can flow, and / or - the compressor wheel (141) in a compression chamber of a compressor housing d it compressor (110) is rotatably arranged, wherein a bearing-side back of the compressor wheel faces an inside of a compressor housing wall over a Radrückenraum in the compressor chamber, wherein in the Radrückenraum a gas, in particular a charge air, circumferentially around an axial direction (z) can flow. According to the invention, it is provided that an inside width (W) of an annular gap (RS) of the wheel back space (13) in the axial direction (z), which prevails in a section (13r) of the wheel back space (13) extending in the radial direction (r), by means of at least one in the section (13r) arranged flow resistance element (1A, 1B) for increasing a flow resistance of the gas flow of the circulating gas along the radial direction (r) is changed.

Description

• – ein Turbinenrad der Turbine und ein Verdichterrad des Verdichters an einer Turboladerwelle angebracht sind, wobei
• – die Turboladerwelle mittels einem Lager drehbar gelagert ist, insbesondere wobei das Lager eine die Turboladerwelle drehbar lagernde Lageranordnung in einem Lagergehäuse aufweist, und
• – das Turbinenrad in einer Turbinenkammer eines Turbinengehäuses der Turbine drehbar angeordnet ist, wobei ein lagerseitiger Rücken des Turbinenrades einer Innenseite einer Turbinengehäusewand über einen Radrückenraum in der Turbinenkammer zugewandt ist, wobei in dem Radrückenraum ein Gas, insbesondere Abgas, umlaufend um eine axiale Richtung strömen kann, und/oder
• – das Verdichterrad in einer Verdichterkammer eines Verdichtergehäuses des Verdichters drehbar angeordnet ist, wobei ein lagerseitiger Rücken des Verdichterrades einer Innenseite einer Verdichtergehäusewand über einen Radrückenraum in der Verdichterkammer zugewandt ist, wobei in dem Radrückenraum ein Gas, insbesondere eine Ladeluft, umlaufend um eine axiale Richtung strömen kann. Die Erfindung betrifft weiter eine Brennkraftmaschine, insbesondere für ein Wasserfahrzeug oder ein Landfahrzeug, vorzugsweise ein Nutzfahrzeug wie einen Kipper oder dergleichen.

The invention relates to a turbomachine with a compressor and a turbine, wherein

• A turbine wheel of the turbine and a compressor wheel of the compressor are mounted on a turbocharger shaft, wherein
• - The turbocharger shaft is rotatably supported by a bearing, in particular wherein the bearing has a turbocharger shaft rotatably supporting bearing assembly in a bearing housing, and
• - The turbine is rotatably disposed in a turbine chamber of a turbine housing of the turbine, wherein a bearing-side back of the turbine wheel faces an inner side of a turbine housing wall over a Radrückenraum in the turbine chamber, wherein in the Radrückenraum a gas, in particular exhaust gas, can flow circumferentially about an axial direction , and or
• - The compressor is rotatably disposed in a compressor chamber of a compressor housing of the compressor, wherein a bearing-side back of the compressor wheel faces an inside of a compressor housing wall over a Radrückenraum in the compressor chamber, wherein in the Radrückenraum a gas, in particular a charge air flow circumferentially about an axial direction can. The invention further relates to an internal combustion engine, in particular for a watercraft or a land vehicle, preferably a commercial vehicle such as a dump truck or the like.

A turbomachine of the type mentioned above, with a compressor and a turbine, is regularly incorporated as a turbocharger in a periphery of an internal combustion engine to suck via the compressor of the turbomachine an air to be supplied to the engine, and to supply them as a compressed charge air to the engine. The compressor is regularly driven by the turbine, which is driven by the exhaust gas emitted by the engine. An internal combustion engine may include an air filter on the charge air side and exhaust gas aftertreatment or exhaust gas recirculation on the exhaust side. Furthermore, the periphery of the internal combustion engine may comprise suitable heat exchangers for cooling the compressed charge air and / or the exhaust gas. A turbomachine of the type mentioned can also be designed in several stages with a first stage and a second stage of a turbocharger; that is to say with a first compressor of a low-pressure stage and a second compressor of a high-pressure stage and with a first turbine of a high-pressure stage and with a second turbine of a low-pressure stage.

A turbomachine is used regularly to increase the power of the engine. The turbocharger shaft is, as explained above, rotatably supported by a bearing. The bearing may have a radial and / or a thrust bearing, and a suitable lubrication system, which is filled with a lubricating fluid such as oil or the like, to support the turbocharger shaft rotatably and frictionless as possible in the bearing assembly of the bearing.

The lubricating fluid regularly comes in contact with the turbocharger shaft and is in contact, in particular in a bearing cavity of the bearing housing. Penetration of the lubricating fluid into a turbine chamber and / or compressor chamber should be prevented. Penetration of the lubricating fluid into the turbine chamber and / or compressor chamber may not only cause deterioration of the exhaust gas values but, moreover, lead to coking in the turbine or compressor due to the elevated temperature in the turbine chamber and / or the compression chamber. Basically, this danger exists in the turbine and, albeit to a lesser extent, also in the compressor.

An initially mentioned turbomachine is, for example, in DE 11 2008 002 729 T5 disclosed. To avoid an oil leak, there is proposed in addition to a seal to increase pressure within a so-called Hitzeschildholraumes between turbine housing wall and bearing housing wall. For this purpose, a suitable cavity between turbine housing and bearing housing is pressurized, namely a cavity channel between said heat shield and the bearing housing. A similar solution is mentioned in the there US 7,086,842 B2 proposed. However, such a concept, which is suitable in itself, requires additional measures in the case parts mentioned and, moreover, can still be improved.

In fact, an additional problem arises from the fact that the oil leakage at the turbocharger shaft is impaired insofar as that in the turbine and / or compressor housing, d. H. in a Radrückenraum the turbine chamber and / or in a Radrückenraum the compression chamber an absolute pressure is generated so that oil can be sucked across the seal away. Moreover, as recognized herein, axial thrusts in the turbine and the compressor may be different so that a resulting axial thrust in one or the other direction of the bearing may initially affect the seal on the turbocharger shaft. In particular, it has been found that an axial thrust of the turbine in comparison to the compressor is comparatively large, so that bearing damage can occur primarily on a counter thrust surface.

An electrically driven turbocharger group with a streamlined back a turbine and compressor wheel or a streamlined inside of a housing wall is in US 2010/0175377 A1 disclosed. In principle, it is known that aerodynamic geometries are selected in order to ensure a low-flow rotation of a turbine wheel and / or compressor wheel in a turbine housing or compressor housing.

However, the aforementioned problem is not considered in known turbomachinery. It is desirable to take account of the oil-tightness and / or the axial thrust problem in a bearing for the turbocharger shaft with an improved device, in particular an improved turbomachine and internal combustion engine.

At this point, the invention begins, whose task is to provide an improved turbomachine and an improved internal combustion engine, which addresses the aforementioned problem. In particular, the turbomachine and the internal combustion engine should be designed to ensure oil leakage and / or reduced susceptibility to axial thrust, preferably both, i. to ensure both the oil-tightness and the reduced Axialschubanfälligkeit. In particular, a pressure in the turbine housing or compressor housing should be increased and / or an axial thrust in the bearing should be reduced.

The task relating to a turbomachine is achieved by the invention with a turbomachine of claim 1.

• – ein Turbinenrad der Turbine und ein Verdichterrad des Verdichters an einer Turboladerwelle angebracht sind, wobei
• – die Turboladerwelle mittels einem Lager drehbar gelagert ist, insbesondere wobei das Lager eine die Turboladerwelle drehbar lagernde Lageranordnung in einem Lagergehäuse aufweist, und
• – das Turbinenrad in einer Turbinenkammer eines Turbinengehäuses der Turbine drehbar angeordnet ist, wobei ein lagerseitiger Rücken des Turbinenrades einer Innenseite einer Turbinengehäusewand über einen Radrückenraum in der Turbinenkammer zugewandt ist, wobei in dem Radrückenraum ein Gas, insbesondere Abgas, umlaufend um eine axiale Richtung strömen kann, und/oder
• – das Verdichterrad in einer Verdichterkammer eines Verdichtergehäuses des Verdichters drehbar angeordnet ist, wobei ein lagerseitiger Rücken des Verdichterrades einer Innenseite einer Verdichtergehäusewand über einen Radrückenraum in der Verdichterkammer zugewandt ist, wobei in dem Radrückenraum ein Gas, insbesondere eine Ladeluft, umlaufend um eine axiale Richtung strömen kann.

The invention is based on a turbomachine with a compressor and a turbine, wherein

• A turbine wheel of the turbine and a compressor wheel of the compressor are mounted on a turbocharger shaft, wherein
• - The turbocharger shaft is rotatably supported by a bearing, in particular wherein the bearing has a turbocharger shaft rotatably supporting bearing assembly in a bearing housing, and
• - The turbine is rotatably disposed in a turbine chamber of a turbine housing of the turbine, wherein a bearing-side back of the turbine wheel faces an inner side of a turbine housing wall over a Radrückenraum in the turbine chamber, wherein in the Radrückenraum a gas, in particular exhaust gas, can flow circumferentially about an axial direction , and or
• - The compressor is rotatably disposed in a compressor chamber of a compressor housing of the compressor, wherein a bearing-side back of the compressor wheel faces an inside of a compressor housing wall over a Radrückenraum in the compressor chamber, wherein in the Radrückenraum a gas, in particular a charge air flow circumferentially about an axial direction can.

According to the invention, it is provided in the turbomachine that a clear width of an annular gap of Radrückenraumes in the axial direction, which prevails in a radially extending portion of Radrückenraumes by at least one arranged in the flow resistance element section to increase a flow resistance of the gas flow of the circulating gas the radial direction is changed.

In the context of the task, the invention also relates to an internal combustion engine of claim 14. The internal combustion engine has an engine and a turbomachine according to the invention, wherein a charge air duct of the engine is connected to the compressor and an exhaust gas duct of the engine to the turbine. The internal combustion engine is advantageously suitable in particular for a watercraft or a land vehicle, preferably a commercial vehicle such as a tipper or the like.

The invention has recognized that a flow resistance in the Radrückenraum can change with a change in the prevailing in the axial direction clear width of an annular gap of the Radrückenraumes. Such a flow resistance in a section extending in the radial direction can be generated in particular via a narrowing and / or widening of the axial width of the annular gap prevailing in the axial direction. For this purpose, at least one flow resistance element can be arranged in the radial section. This measure basically applies to a turbine wheel back space as well as, additionally or alternatively, to a compressor wheel back space.

The concept of the invention is suitable for increasing an absolute pressure in the Radrückenraum at an inner radius of a shaft near region of the turbocharger shaft in Radrückenraum and thus promotes the oil seal of a seal on a turbocharger shaft. Usually, an absolute pressure in a Radrückenraum at an inner radius of a shaft near region of the turbocharger shaft without flow resistance element is lower.

In addition, the flow resistance element in the Radrückenraum - by increasing the prevailing in the Radrückraum absolute pressure - depending on load points on the turbocharger, existing axial thrusts or compensates for them. In particular, axial thrusts are reduced in the compressor wheel back space and / or Turbinenradrückenraum or aligned. As a result, axial bearing damage to a counter thrust surface is avoided.

Advantageous developments of the invention can be found in the dependent claims and specify in particular advantageous ways to realize the above-described concept within the scope of the problem and with regard to further advantages.

• – jeweils mittels dem wenigstens einen Strömungswiderstandselement entlang der radialen Richtung verengt oder aufgeweitet oder abwechselnd verengt und aufgeweitet ist in dem sich in radialer Richtung erstreckenden Abschnitt. Auf diese Weise ist besonders vorteilhaft die lichte Weite mittels dem Strömungswiderstandselement zur Erhöhung eines Strömungswiderstands der Gasströmung verändert.

In particular, it is provided that the clear width of the annular gap of the turbine Radrückenraumes in the turbine chamber and / or the inside diameter of the annular gap of the compressor Radrückenraumes in the compression chamber,

• - Narrows in each case by means of the at least one flow resistance element along the radial direction or widened or alternately narrowed and widened in the radially extending portion. In this way, the clear width is particularly advantageously changed by means of the flow resistance element to increase a flow resistance of the gas flow.

The flow resistance of the gas flow of the circulating gas along the radial direction is preferably formed by means of the flow resistance element, which extends into the wheel back space in the axial direction for changing in sections, in particular constriction and / or widening, of the annular gap. The flow resistance element thus acts comparatively effective.

In the context of a particularly preferred development, the flow resistance of the gas flow of the circulating gas along the radial direction can be formed by means of a flow resistance element in the form of a contour. A contour can be adapted particularly well to the flow conditions and attach comparatively easily.

In the context of a particularly preferred first variant, the contour can be mounted on the back of the turbine wheel and / or compressor wheel, in particular applied or introduced. In the context of a particularly preferred second variant, the contour may be additionally or alternatively applied to the inside of a turbine housing wall and / or compressor housing wall, in particular applied or introduced. Both the measures of the first variant and the second variant have proved advantageous, alone or in combination, to narrow and / or widen the clear width of an annular gap of the wheel back space by means of at least one flow resistance element in a section extending in the radial direction.

Preferably, a flow velocity of the gas flow of the circulating gas along the radial direction of Radrückenraumes, in particular the charge air and / or the exhaust gas, given in the radial direction of the Radrückenraumes and the flow resistance element is preferably designed such that the flow velocity in the radial direction and / or circumferential direction of Radrückenraumes increased sublinear. A particularly preferred exemplary explanation is to detail in the 4 (A) shown.

Specifically, in the wheel back space, an amount of a pressure gradient is given from an inner radius of a shaft-proximal portion of the turbocharger shaft to an outer radius of a shaft-distal portion of the turbocharger shaft. Preferably, the flow resistance element is designed such that the amount of the pressure gradient is less than with a linear increase in the flow velocity. A particularly preferred exemplary explanation is to detail in the 4 (B) shown. A relationship between flow velocity and pressure gradient arises in principle according to the current thread theory as they are, for example, in Zierep "Fundamentals of Fluid Mechanics", 5th edition, Springer textbook on pages 45 to 56 is described. Further details are in the context of the drawing on the basis of 4 to 6 explained. Preferably, the flow resistance element is designed such that an absolute pressure in the Radrückenraum at an inner radius of a shaft near region of the turbocharger shaft has a higher amount to an absolute pressure in a Radrückenraum at an inner radius of a shaft near region of the turbocharger shaft without flow resistance element.

Advantageously, the turbine chamber and a bearing cavity of the bearing housing and / or the compressor chamber and a bearing cavity of the bearing housing are each separated by a radially extending to the turbocharger shaft partition comprising a turbine housing wall and a bearing housing wall and / or a compressor housing wall and a bearing housing wall, wherein the partition against the Turbocharger shaft is sealed, in particular by a sealing hub, shaft seal or the like. With such a partition wall, the concept of the invention can be implemented particularly advantageously.

In particular, the partition wall may be hollow, wherein the partition wall in each case comprises an annular housing running between the turbine housing wall and the bearing housing wall and / or between the compressor housing wall and the bearing housing wall. A cavity of the dividing wall can also be advantageously used for the concept of the invention, in particular by pressurizing it.

In particular, the partition and / or a radially extending to the turbocharger shaft radial part of the turbine housing wall and / or the compressor housing wall may be wholly or partially formed as a heat shield. This can advantageously reduce or avoid heat transfer into the bearing. Preferably, an inside of the heat shield carries the flow resistance element, in particular, the flow resistance element is formed in the shape of a contour.

Advantageously, the partition wall is formed as one of the bearing housing and / or as one of the turbine housing and / or as a separate from the compressor housing and connected to these ring part.

In particular, the heat shield is designed as a jet disk and the inside of the jet disk carries a flow resistance element in the form of a contour. The concept of the invention can thus be implemented advantageously in the context of the heat shield and the jet disk.

Embodiments of the invention will now be described below with reference to the drawing. This is not necessarily to scale the embodiments, but the drawing, where appropriate for explanation, executed in a schematized and / or slightly distorted form. With regard to additions to the teachings directly recognizable from the drawing reference is made to the relevant prior art. It should be noted that various modifications and changes may be made in the form and detail of an embodiment without departing from the general idea of the invention. The disclosed in the description, in the drawing and in the claims features of the invention may be essential both individually and in any combination for the development of the invention. In addition, all combinations of at least two of the features disclosed in the description, the drawings and / or the claims fall within the scope of the invention. The general idea of the invention is not limited to the exact form or detail of the preferred embodiment shown and described below or limited to an article which would be limited in comparison to the subject matter claimed in the claims. For the given design ranges, values within the stated limits should also be disclosed as limit values and be arbitrarily usable and claimable. For simplicity, the same reference numerals are used below for identical or similar parts or parts with identical or similar function.

Further advantages, features and details of the invention will become apparent from the following description of the preferred embodiments and from the drawing; this shows in:

1 a schematic representation of an internal combustion engine with an engine and a turbomachine according to a preferred embodiment;

2 a detail of a turbomachine according to the prior art, in which a Radrückenraum in a turbine chamber has a substantially constant in the axial direction prevailing clear width of an annular gap - and thus with a correspondingly high radial pressure gradient (p2'-p1 ') -;

3A a first particularly preferred embodiment of a turbomachine, in which - for example in the turbine - the prevailing axial width of an annular gap of the Radrückenraumes is repeatedly widened along the radial direction (r), wherein a corresponding flow resistance element is arranged on the inside of a turbine housing wall;

3B a particularly preferred second embodiment, in contrast to 3A a corresponding flow resistance element is arranged on the back of the turbine wheel instead of on the inside of a turbine housing wall;

4A . 4B a schematic representation of a velocity profile (A) and pressure curve (B) along the radius of a rigid body vortex in a Radrückenraum in an embodiment of the invention compared to the prior art;

5 a schematic representation of the problem of leakage in the prior art due to in 4A . 4B dashed lines shown speed and pressure curves;

6A . 6B a schematic schematic diagram according to the specific embodiment of 3A . 3B which the in 4A and 4B associated with continuous speed and pressure curves are assigned;

7A . 7B Details of 3A and 3B with respect to a partition wall of the turbomachine.

1 shows an internal combustion engine 1000 with a motor 200 , in its charge air and exhaust peripherals 300 a turbomachine 100 is involved. The turbo machine 100 has a compressor 110 and a turbine 120 on, with a turbocharger shaft 140 by means of a warehouse 130 is rotatably mounted and a compressor wheel 141 of the compressor 110 and a turbine wheel 142 the turbine 120 at the turbocharger shaft 140 is appropriate. The compressor 110 is to a charge air duct 111 connected to charge air LL, wherein the compressor air L is supplied from the environment via an air filter 112 from the compressor 110 is sucked. The output from the engine exhaust AG in an exhaust system 121 becomes the turbine 120 fed to the exhaust system 121 connected. The exhaust gas AG is then connected to an exhaust gas aftertreatment and / or an exhaust gas recirculation 122 passed. The driven via the exhaust AG turbine wheel 142 the turbine 120 in turn drives over the turbocharger shaft 140 the compressor wheel 141 of the compressor 110 to compress the air L to charge air LL.

2 In the prior art shows a detail of a turbine T120 with a schematically illustrated turbocharger shaft T140 and, on this, a rotatably mounted turbine wheel TR in a turbine chamber TK for compression of exhaust gas AG. Between the back TRR of the turbine wheel TR and an inside TGI of a turbine housing wall TG is formed a Radrückenraum RR, with a pressure gradient p2'-p1 'in the radial direction. At an inner radius r1 of a shaft-near portion of the turbocharger shaft T140, there is an absolute pressure p1 'and a flow velocity c1' of a gaseous flow of a rigid body vortex, the absolute pressure p1 'being significantly less than an absolute pressure p2' in an outer radius r2 of a shaft-distal portion of the turbocharger shaft T140; ie the prevailing pressure p2 'of the rigid body vortex there, as well as its speed c2', is significantly above the pressure p1 'or speed c1'.

Due to these pressure conditions, in particular in the region of the inner radius r1, there are two main problems which have been recognized by the invention. On the one hand, lubricating fluid "oil" is drawn into the wheel back space RR in the axial direction z and can there lead to a risk of coking due to the prevailing temperature conditions in the wheel back space RR. The annular gap RS of the Radrückraumes RR is relatively narrow and designed with low flow resistance.

On the other hand, possibly different pressure and velocity ratios p1 ', c1' of the gas flow in the turbine T120-unlike the compressor V110 mounted on the same turbocharger shaft T140-introduce different axial thrusts into a bearing La, in the present case only symbolically between the turbine T120 and the compressor V110 is shown. This can lead to axial bearing damage occurring in bearings La of the prior art at a corresponding counter thrust surface.

3A and 3B show two different variants of a particularly preferred embodiment of a turbomachine. The concept of the invention is based on 3A and 3B exemplary for a turbine 120 for the sake of simplicity, identical reference numerals are used here for identical or similar features or features of identical or similar function. The system of the turbine 120 explained invention can be equally - additionally or alternatively - on a compressor 110 apply even if this in the aftermath too 1 not shown below.

In detail shows 3A and 3B a turbine 120 in two different variants of a turbomachine 1000 as they are in 1 is shown in detail. Both turbines 120 have a turbine wheel 20 that in a turbine chamber 10 a turbine housing 30 is rotatably arranged. The turbine wheel 20 In this case, it is driven by exhaust gas AG, which extends radially along a radius r into a diffuser 11 the turbine chamber enters and via an outlet 12 axially exits, ie in the axial direction z, which is designated here along the axis A. In 3A as well as in 3B is recognizable that a back 21.A respectively. 21.B of the turbine wheel 20 an inside 31.A respectively. 31.B the turbine housing wall 31 is facing. Between the inside 31.A and the back 21.A the turbine 120 of the 3B or between the inside 31.B and the back 21.B the turbine 120 of the 3B is a bike back room 13 in the turbine chamber 10 formed with an annular gap RS.

According to the concept of the invention, the turbine is in both embodiments 120 of the 3A and 3B a prevailing in the axial direction z clear width W of a disc-like annular gap RS of Radrückenraums 13 in a section extending in the radial direction r 13r repeatedly widened; You could also say that the actual width of Radrückenraums 13 in the radial section 13r alternately increases and decreases, ie, narrows or widens alternately along the radial direction r. In the present case is a clear width W with a flow resistance element 1A . 1B from Stegen 13S (ie annular ribs) formed here as a contour KA, KB alternately with the intermediate grooves 13N (ie annular grooves) can be seen - see 7A . 7B in detail. In this case, the contour KA is present in the embodiment of 3A on the inside 31.1A the turbine housing wall 31 attached and the contour KB on the back 21.B of the turbine wheel 20 ,

The flow resistance element 1A . 1B is formed such that a flow velocity c in the radial direction and / or circumferential direction of Radrückenraumes increased sublinear, as it is in 4A is shown as a solid line compared to the dashed line of the prior art. The flow resistance element 1A . 1B is further formed such that in the Radrückenraum 13 an amount of a pressure gradient p1-p2 from an inner radius r1 of a shaft-proximal region of the turbocharger shaft to an outer radius r2 of a shaft-remote region of the turbocharger shaft is smaller than a linear increase in a flow velocity c in the radial direction r and / or circumferential direction of the Radrückenraumes 13 like it 4 is shown.

4A and 4B make it clear that, as by comparing the 5 on the one hand with the 6A (corresponding 3A ) and 6B (corresponding 3B on the other hand immediately gives an absolute pressure p1 in the Radrückenraum 13 in the radial section 13r at an inner radius r1 of a shaft-near portion of the turbocharger shaft has a higher magnitude than an absolute pressure p1 'in a wheel back space at an inner radius of a shaft near portion of the turbocharger shaft without flow resistance element. This has the consequence that the tightness of a gasket TD of 5 with respect to a lubricating fluid "oil" (over the prior art) is significantly improved.

In other words, by increasing the absolute pressure p1 according to the embodiments of FIGS 3A . 3B (or 6A . 6B ) relative to a pressure in the prior art p1 'increases the absolute pressure near the shaft near the turbocharger shaft - so are the forces acting on the lubricating fluid suction forces in the Radrückenraum 13 in the radial section 13r , but in particular in the near-well region of the first radius r1, as well as the axial thrust decreases synergistically.

The corresponding basic formulas are given by considering a rigid body vortex in Radrückenraum 13 from the remarks of Zierep "Fundamentals of Fluid Mechanics" (5th edition, Springer textbook) on the current thread theory of hydro- and aerodynamics on pages 45 to 59 of Chapter 4.1.3 ff. , The corresponding differential equation (4.16) and its solution (exemplarily for a density ρ of the gas assumed to be constant, 4.27 there) are listed below as an equation.

7A and 7B show a detail of already in 3A and 3B illustrated turbomachine 100 concerning the design of the Radrückenraumes 13 with a sectional narrowing and / or widening by the contour KA, KB, ie in this case a repeated widening of the width W of the annular gap RS along the radial direction r, as with reference to FIG 3A and 3B described.

Specifically, there is seen that the turbine chamber 10 and an unspecified bearing cavity of the bearing 130 with the bearing housing 50 through a radial to the turbocharger shaft 140 (along the axis A) extending hollow partition 40 are separated. The partition 40 each includes one between the turbine housing wall 31 and the bearing housing wall 51 extending annular channel 41 and as a whole is designed as a heat shield. The heat shield is especially in the turbine chamber 10 facing wall of the partition 40 comprising the inside 31.A . 31.B the turbine housing wall 31 , designed as a jet disk. In the embodiment of the 7A is this jet disc with the aforementioned contour KA to represent a flow resistance element 1A Mistake. In the embodiment of the 7B is the jet disk on its inside to the turbine chamber 10 flat design; instead wears the back 21.B of the turbine wheel 20 the aforementioned contour KB for forming a flow resistance element 1B ,

The contour KA, KB is present as an alternating, arranged in the radial direction sequence of grooves 13N and jetties 13S educated. The grooves 13N have a substantially semi-circular unspecified reason. The bridges 13S are formed on their upper side substantially rectangular. Due to the alternating depth of the surface on the inside 31.A or on the back 21.B in the radial direction r, a flow resistance is generated such that in the radial direction r and / or circumferential direction the flow velocity c of the rigid body vortex at the rear of the turbine wheel 20 in the Radrückenraum 13 is reduced and a pressure gradient p2-p1 in the radial direction r - as explained above - is also reduced. Overall, this leads to being below the dividing wall 40 there is no longer a pull on an oil in the bearing cavity through the seal TD or only in reduced degree. In addition, axial thrusts on the bearing 130 reduced.

LIST OF REFERENCE NUMBERS

1A, 1B

 Flow resistance element

TK, 10

 turbine chamber

11

 diffuser

12

 outlet

13

 Radrückenraum

13r

 radial section

13S

 web

13N

 groove

20

 turbine

21.A, 21.B

 Back of the turbine wheel of the turbine

30

 turbine housing

31

Turbine housing wall

31.A, 31.B

 Inside the turbine housing wall

40

 partition wall

50

bearing housing

51

 Bearing housing wall

1000

 Internal combustion engine

100

 turbomachinery

V110, 110

 compressor

111

 Charge air ducting

112

 air filter

T120, 120

 turbine

121

 exhaust system

122

 Exhaust gas recirculation

130

 camp

T140, 140

 turbocharger shaft

141

 compressor

142

 turbine

200

 engine

300

 exhaust peripherals

AG

 exhaust

L

 air

LL

 charge air

La

 camp

TR, 20

 turbine

TRR

 Back of the turbine wheel

TG

 Turbine housing wall

TGI

 Inside the turbine housing wall

TD

 poetry

RR

 Radrückenraum

RS

 annular gap

TGI

Turbine casing inner wall

p1, p2, p1 ', p2'

 print

c1, c2, c1 ', c2'

 flow rate

r1

 inner radius

r2

 outer radius

W

 clear width

z

 axial direction

r

 radial direction

KA, KB

 contour

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 112008002729 T5 [0005]
• US7086842 B2 [0005]
• US 2010/0175377 A1 [0007]

Cited non-patent literature

• Zierep "Fundamentals of Fluid Mechanics", 5th edition, Springer textbook on pages 45 to 56 [0023]
• Zierep "Fundamentals of Fluid Mechanics" (5th edition, Springer textbook) on the current thread theory of hydro- and aerodynamics on pages 45 to 59 of chapter 4.1.3 ff. [0049]

Claims (14)

Turbomachine ( 100 ) with a compressor ( 110 ) and a turbine ( 120 ), wherein - a turbine wheel ( 20 ) of the turbine ( 120 ) and a compressor wheel of the compressor ( 110 ) on a turbocharger shaft ( 140 ), wherein - the turbocharger shaft ( 140 ) by means of a bearing ( 130 ) is rotatably mounted, in particular wherein the bearing ( 130 ) has a bearing assembly rotatably supporting the turbocharger shaft in a bearing housing, and - the turbine wheel ( 142 . 20 ) in a turbine chamber ( 10 ) of a turbine housing ( 30 ) of the turbine ( 120 ) is rotatably arranged, wherein a bearing-side back ( 21.A . 21.B ) of the turbine wheel ( 20 ) an inside ( 31.A . 31.B ) a turbine housing wall ( 31 ) over a Radrückenraum ( 13 ) in the turbine chamber ( 10 ), wherein in the Radrückenraum a gas, in particular exhaust gas, circumferentially around an axial direction (z) can flow, and / or - the compressor wheel ( 141 ) in a compression chamber of a compressor housing of the compressor ( 110 ), wherein a bearing-side back of the compressor wheel faces an inside of a compressor housing wall over a Radrückenraum in the compressor chamber, wherein in the Radrückenraum a gas, in particular a charge air, circumferentially around an axial direction (z) can flow, characterized in that a clear width (W) of an annular gap (RS) of Radrückenraumes ( 13 ) in the axial direction (z), which in a radially extending (r) extending portion ( 13r ) of Radrückenraumes ( 13 ) prevails, by means of at least one in the section ( 13r ) arranged flow resistance element ( 1A . 1B ) is changed to increase a flow resistance of the gas flow of the circulating gas along the radial direction (r). Turbomachine according to claim 1, characterized in that - the clear width (W) of the annular gap of the turbine Radrückenraumes ( 13 ) in the turbine chamber ( 10 ) and / or the clear width of the annular gap of the compressor Radrückenraumes in the compression chamber, - each by means of at least one flow resistance element ( 1A . 1B ) is narrowed or widened or alternatively narrowed and widened along the radial direction (r) in the radially extending section (FIG. 13r ). Turbomachine according to claim 1 or 2, characterized in that the flow resistance of the gas flow of the circulating gas along the radial direction (r) by means of the flow resistance element ( 1A . 1B ) formed in the Radrückenraum ( 13 ) in the axial direction (z) extends into the section-wise change, in particular constriction and / or expansion, of the annular gap (RS). Turbomachine according to one of claims 1 to 3, characterized in that the flow resistance of the gas flow of the circulating gas along the radial direction (r) by means of a flow resistance element ( 1B ) is formed in the shape of a contour (KB) on the back ( 21.B ) of the turbine wheel ( 142 . 20 ) and / or compressor wheel ( 141 ) is mounted, in particular applied or introduced. Turbomachine according to one of claims 1 to 4, characterized in that the flow resistance of the gas flow of the circulating gas along the radial direction (r) by means of a flow resistance element ( 1A ) is formed in the form of a contour (KA,) on the inside ( 31.A ) a turbine housing wall ( 31 ) and / or compressor housing wall is mounted, in particular applied or introduced. Turbomachine according to one of claims 1 to 5, characterized in that a flow velocity (c) of the gas flow of the circulating gas along the radial direction (r) and / or circumferential direction of Radrückenraumes, in particular the charge air and / or the exhaust gas is given, and the flow resistance element ( 1A . 1B ) is formed such that the flow velocity (c) in the radial direction (r) and / or circumferential direction of the Radrückenraumes ( 13 ) increased sublinearly ( 4 (A) ). Turbomachine according to claim 6, characterized in that in the Radrückenraum ( 13 ) an amount of a pressure gradient (p1-p2) is given from an inner radius (r1) of a shaft-near region of the turbocharger shaft to an outer radius (r2) of a shaft-remote region of the turbocharger shaft, and the flow resistance element ( 1A . 1B ) is formed such that the magnitude of the pressure gradient (p1-p2) is lower than in the case of a linear increase in the flow velocity (c) in the radial direction (r) and / or circumferential direction of the Radrückenraumes ( 13 ) ( 4 (B) ). Turbomachine according to one of claims 1 to 7, characterized in that the flow resistance element ( 1A . 1B ) is formed such that an absolute pressure (p1) in the Radrückenraum ( 13 ) at an inner radius (r1) of a shaft-near region of the turbocharger shaft has a higher magnitude than an absolute pressure (p1 ') in a Radrückenraum ( 13 ) at an inner radius (r1) of a shaft near region of the turbocharger shaft without flow resistance element. Turbomachine according to one of claims 1 to 8, characterized in that the turbine chamber ( 10 ) and a bearing cavity of the bearing housing ( 30 ) and / or the compression chamber and a bearing cavity of the bearing housing ( 30 ) by a respective radial to the turbocharger shaft ( 140 ) extending partition ( 40 ), which comprises a turbine housing wall and a bearing housing wall and / or a compressor housing wall and a bearing housing wall, wherein the partition wall ( 40 ) is sealed against the turbocharger shaft, in particular by a sealing hub, shaft seal or the like. Turbomachine according to claim 9, characterized in that the partition ( 40 ) is hollow, wherein the partition ( 40 ) one each between turbine housing wall ( 31 ) and bearing housing wall ( 51 ) and / or a running between compressor housing wall and bearing housing wall annular channel ( 41 ). Turbo machine according to claim 9 or 10, characterized in that - the partition ( 40 ) and / or a radially extending to the turbocharger shaft radial part of the turbine housing wall ( 31 ) and / or the compressor housing wall is wholly or partially formed as a heat shield, wherein - an inside ( 31.A ) of the heat shield, the at least one flow resistance element ( 1A . 1B ), in particular the flow resistance element ( 1A . 1B ) in the form of a contour (KA, KB) is formed. Turbomachine according to one of claims 9 to 11, characterized in that the partition ( 40 ) as one from the bearing housing ( 50 ) and / or as one from the turbine housing ( 30 ) and / or is formed as a separate from the compressor housing and connected to these ring part. Turbomachine according to claim 11 or 12, characterized in that the heat shield is formed as a jet disc and the inside of the jet disc a flow resistance element ( 1A ) in the form of a contour (KA). Internal combustion engine ( 1000 ), in particular for a watercraft or a land vehicle, preferably a commercial vehicle such as a tipper or the like, with an engine ( 200 ) and a turbomachine ( 100 ) according to one of claims 1 to 13, characterized in that a charge air guide ( 111 ) of the engine to the compressor ( 110 ) and an exhaust system ( 121 ) of the engine to the turbine ( 120 ) connected.

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