DE102014218782A1 - Charged internal combustion engine with liquid-cooled turbine and bearing housing - Google Patents

Abstract

The invention relates to a supercharged internal combustion engine with at least one liquid-cooled turbine (1) of an exhaust gas turbocharger, which is connected to a bearing housing (3a), in which - the turbine (1) has a turbine housing (2) in which at least one on a rotatable shaft ( 4a) mounted impeller (4) is arranged, wherein in the housing (2) at least one emanating from an exhaust gas inlet opening, exhaust leading flow channel (5) spirally around the impeller (4), - the bearing housing (3a), which Receiving the rotatably mounted shaft (4a) is connected to a transverse to the shaft (4a) mounting flange surface (6a) with the turbine housing (2) is connected, and - the turbine housing (2) for forming a cooling at least one in the turbine housing ( 2) arranged coolant channel (2b, 2c), said at least one coolant channel (2b, 2c) in the housing (2) at least partially annularly around the shaft (4a) extends, wherein - at least a first coolant channel (2b) on the bearing housing (3a) facing side of the at least one impeller (4) in the turbine housing (2) is arranged, said at least one first coolant channel (2b) in a mounting flange (6a) receiving and forming flange (6) is arranged, the mounting flange surface (6a) is open towards and from the bearing housing (3a) is closed in the assembled state lid.

Description

• – die Turbine ein Turbinengehäuse, in dem mindestens ein auf einer drehbaren Welle gelagertes Laufrad angeordnet ist, umfasst, wobei sich im Gehäuse mindestens ein von einer Abgaseintrittsöffnung ausgehender, Abgas führender Strömungskanal spiralförmig um das Laufrad erstreckt,
• – das Lagergehäuse, welches zur Aufnahme der drehbar gelagerten Welle dient, an einer quer zur Welle verlaufenden Montage-Flanschfläche mit dem Turbinengehäuse verbunden ist, und
• – das Turbinengehäuse zur Ausbildung einer Kühlung mindestens einen im Turbinengehäuse angeordneten Kühlmittelkanal aufweist, wobei dieser mindestens eine Kühlmittelkanal sich im Gehäuse zumindest abschnittsweise ringförmig um die Welle erstreckt.

The invention relates to a supercharged internal combustion engine with at least one liquid-cooled turbine of an exhaust gas turbocharger, which is connected to a bearing housing, in which

• The turbine comprises a turbine housing in which at least one impeller mounted on a rotatable shaft is arranged, wherein in the housing at least one exhaust duct leading from an exhaust gas inlet opening extends spirally around the impeller,
• - The bearing housing, which serves to receive the rotatably mounted shaft is connected to a transverse to the shaft mounting flange surface with the turbine housing, and
• - The turbine housing for forming a cooling at least one arranged in the turbine housing coolant channel, said at least one coolant channel extends in the housing at least partially annularly around the shaft.

An internal combustion engine of the type mentioned is used as a motor vehicle drive. In the context of the present invention, the term internal combustion engine includes diesel engines and gasoline engines, but also hybrid internal combustion engines, which use a hybrid combustion process, and hybrid drives, which in addition to the internal combustion engine comprise an electric motor which can be electrically connected to the internal combustion engine, which receives power from the internal combustion engine or as switchable auxiliary drive additionally delivers power.

Internal combustion engines have a cylinder block and a cylinder head, which are interconnected to form the cylinder. As part of the charge exchange, the exhaust of the combustion gases via the outlet openings and the filling of the cylinder via the inlet openings takes place. In order to control the charge exchange, an internal combustion engine requires control devices, for example globe valves, and actuators for actuating the control members. The required for the movement of the valves valve actuating mechanism including the valves themselves is referred to as a valve train.

The exhaust pipes, which connect to the outlet openings of the cylinder, are at least partially integrated in the cylinder head according to the prior art and are combined into a single overall exhaust gas line or a plurality of total exhaust gas lines. The combination of exhaust pipes to an overall exhaust line is referred to as exhaust manifold.

Downstream of the at least one manifold, the exhaust gases are then frequently fed to a turbine, for example, the turbine of an exhaust gas turbocharger, and optionally passed through one or more exhaust aftertreatment systems.

The at least one turbine of the internal combustion engine according to the invention is the turbine of an exhaust gas turbocharger. The charge is used primarily to increase the performance of the internal combustion engine. The air required for the combustion process is compressed, which allows each cylinder per working cycle, a larger air mass can be supplied. As a result, the fuel mass and thus the medium pressure can be increased.

The charge is a suitable means to increase the capacity of an internal combustion engine with unchanged displacement, or to reduce the displacement at the same power. In any case, the charging leads to an increase in space performance and a lower power mass. Under the same vehicle boundary conditions, the load spectrum can thus be shifted to higher loads, where the specific fuel consumption is lower. Charging therefore supports the constant effort in the development of internal combustion engines to minimize fuel consumption, d. H. to improve the efficiency of the internal combustion engine.

Compared to a mechanical supercharger, the advantage of an exhaust gas turbocharger is that no mechanical connection is required for transmitting power between the supercharger and the internal combustion engine. While a mechanical supercharger obtains the energy required for its drive directly from the internal combustion engine, the exhaust gas turbocharger uses the exhaust gas energy of the hot exhaust gases.

The manufacturing costs for the turbine are comparatively high, since the material used for the thermally highly stressed turbine housing - often nickel-containing - material is expensive, especially in comparison to the material preferably used for the cylinder head; for example aluminum. Not only the material costs per se are comparatively high, but also the costs for the processing of these materials used for the turbine housing.

It follows from the foregoing that it would be extremely advantageous in terms of cost if a turbine could be provided that could be made from a less expensive material, such as gray cast iron or aluminum.

The use of aluminum would also be advantageous in terms of the weight of the turbine, especially when it is considered that a close-coupled arrangement of the turbine leads to a relatively large-sized, voluminous housing, since the connection of the turbine and cylinder head by means of flange and screws due to the limited space requires a large turbine inlet area and also because of the required access for the assembly tools , The voluminous housing brings a correspondingly high weight with it. The weight advantage of aluminum over a highly resilient material is particularly evident in a turbine arranged close to the engine due to the comparatively high use of material.

In order to use more cost-effective materials for the production of the turbine, the turbine according to the prior art with a cooling, for example, with a liquid cooling, equipped, which greatly reduces the thermal load of the turbine or the turbine housing by the hot exhaust gases and thus the Use of thermally less resilient materials allows. A liquid-cooled turbine is particularly suitable for an exhaust gas turbocharging of an internal combustion engine, in which the at least one turbine is subject to particularly high thermal loads due to the high exhaust gas temperatures and therefore cooling of the turbine is particularly advantageous.

In general, the turbine housing is provided to form the cooling with a coolant jacket. Both concepts are known from the prior art, in which the housing is a casting and the coolant jacket is formed as part of the casting process as an integrated coolant jacket of a monolithic housing, as well as concepts in which the housing is modular, wherein in the context of Assembly, a cavity is formed, which serves as a coolant jacket.

A designed according to the latter concept turbine describes, for example, the German patent application DE 10 2008 011 257 A1 , A liquid cooling of the turbine is formed by the fact that the actual turbine housing is provided with a casing, so that forms a cavity between the housing and the at least one spaced-apart formwork element, can be introduced into the coolant. The casing extended by the casing then includes the coolant jacket.

The EP 1 384 857 A2 also discloses a turbine whose housing is equipped with a coolant jacket.

The DE 10 2007 017 973 A1 describes a kit for forming a steam-cooled turbine casing.

Due to the high specific heat capacity of a liquid, in particular of the commonly used water-glycol mixture, the housing by means of liquid cooling large amounts of heat can be withdrawn. The heat is released inside the housing to the coolant and removed with the coolant. The heat given off to the coolant is removed from the coolant again in a heat exchanger.

In principle, it is possible to equip the liquid cooling of the turbine with a separate heat exchanger or - in a liquid-cooled internal combustion engine - the heat exchanger of the engine cooling, d. H. to use the heat exchanger of another liquid cooling, for this purpose. The latter requires only appropriate connections of both circuits.

However, it should be considered in this connection that the amount of heat to be absorbed by the coolant in the turbine can be 40 kW or more if materials which are not very durable, such as aluminum, are used to produce the housing. The coolant to extract such a large amount of heat in the heat exchanger and dissipate by means of air flow to the environment turns out to be problematic.

Although modern motor vehicle drives are equipped with powerful fan motors in order to provide the air mass flow required for a sufficiently high heat transfer at the heat exchangers. But another, relevant for the heat transfer parameters, namely the surface provided for the heat transfer, can not be made arbitrarily large or enlarged, since the space in the front-end area of a vehicle, where the various heat exchangers usually arranged be limited.

Modern motor vehicles often have - in addition to the heat exchanger of the engine cooling - on other heat exchangers, in particular cooling devices. On the intake side of a supercharged internal combustion engine often a charge air cooler is arranged, which contributes to a better filling of the cylinder. In order to maintain a maximum permissible oil temperature, the heat release via the oil sump due to heat conduction and natural convection is often no longer sufficient, so that an oil cooler is provided in individual cases.

In addition, modern internal combustion engines are increasingly being equipped with exhaust gas recirculation fitted. The exhaust gas recirculation is a measure to counteract the formation of nitrogen oxides. In order to achieve a significant reduction in nitrogen oxide emissions, high exhaust gas recirculation rates are required, which make extensive cooling of the recirculated exhaust gas, ie a compression of the exhaust gas by cooling, unavoidable. Other coolers can be provided, for example for cooling the transmission oil in automatic transmissions and / or for cooling hydraulic fluids, in particular hydraulic oil, which is used in the context of hydraulically actuated adjusting devices or for steering assistance. The air conditioning condenser of an air conditioning system is also a heat exchanger, which has to give off heat to the environment during operation, so requires a sufficiently high air flow and therefore is to be arranged in the front-end area.

Due to the very limited space in the front-end area and the large number of heat exchangers, the individual heat exchangers can not be dimensioned according to requirements.

The possibility of arranging a sufficiently large heat exchanger for the liquid cooling of the turbine in the front-end area, in order to dissipate the incurred when using thermally less resilient materials high amounts of heat can be de facto not given.

In the constructive design of a cooled turbine, therefore, a compromise between cooling capacity and material is required, where one basically aims to cool the turbine only to the extent that actually requires the material used to in this way the exhaust enthalpy of the hot exhaust gases, the relevant is determined by the exhaust gas temperature to be able to use optimally.

The above considerations have led to the prior art no longer providing a coolant jacket in the conventional sense in the turbine housing of modern turbines, which completely envelopes or sheathed the at least one impeller of the turbine. Rather, a minimalist cooling of the turbine housing is preferred, in which at least one coolant channel in the housing - at least partially - extends annularly around the shaft, wherein the at least one coolant channel in a section along the shaft sweeps or covers a flow channel only in a limited angular range α , For example, with α ≤ 45 °, α ≤ 35 ° or α ≤ 25 °, and no longer coat-like as large as possible. The coolant channel does not have to be arcuate, but may also meander, preferably around its main extension direction, in a labyrinthine manner.

The largest possible sheathing of the impeller and thus the largest possible heat dissipation are not sought. Rather, the cooling capacity is deliberately limited by the at least one coolant channel is dimensioned smaller than usual. The cooling capacity is limited by the limited heat transfer area provided.

By this measure, the maximum amount of heat to be dissipated is reduced or limited in an advantageous manner. This eliminates the problem of having to dissipate very large amounts of heat absorbed by the coolant in the turbine.

Corresponding to the moderate cooling capacity is to choose a corresponding material for the production of the turbine, namely gray cast iron or steel casting or the like.

In practice, however, it has proven to be difficult or not feasible to form a coolant channel with a maximum diameter of less than 10 millimeters or 8 millimeters in the context of a casting process as an integrated coolant channel of a monolithic housing. The sand cores to be used frequently break and the sand used for the cores can often not be completely removed during reworking after casting. The residue-free removal of the cores or of the sand, however, is absolutely necessary in order not to destroy or damage the cooling of the assembled turbine during operation.

In light of the above, it is the object of the present invention to provide a supercharged internal combustion engine according to the preamble of claim 1, which is optimized in terms of the material and the cooling of the turbine, d. H. whose turbine has a minimalist cooling of the turbine housing, in which the at least one coolant channel is smaller in size.

• – die Turbine ein Turbinengehäuse, in dem mindestens ein auf einer drehbaren Welle gelagertes Laufrad angeordnet ist, umfasst, wobei sich im Gehäuse mindestens ein von einer Abgaseintrittsöffnung ausgehender, Abgas führender Strömungskanal spiralförmig um das Laufrad erstreckt,
• – das Lagergehäuse, welches zur Aufnahme der drehbar gelagerten Welle dient, an einer quer zur Welle verlaufenden Montage-Flanschfläche mit dem Turbinengehäuse verbunden ist, und
• – das Turbinengehäuse zur Ausbildung einer Kühlung mindestens einen im Turbinengehäuse angeordneten Kühlmittelkanal aufweist, wobei dieser mindestens eine Kühlmittelkanal sich im Gehäuse zumindest abschnittsweise ringförmig um die Welle erstreckt,

und die dadurch gekennzeichnet ist, dass

• – mindestens ein erster Kühlmittelkanal auf der dem Lagergehäuse zugewandten Seite des mindestens einen Laufrades im Turbinengehäuse angeordnet ist, wobei dieser mindestens eine erste Kühlmittelkanal in einem die Montage-Flanschfläche aufnehmenden und ausbildenden Flansch angeordnet ist, zur Montage-Flanschfläche hin offen ist und vom Lagergehäuse im montierten Zustand deckelartig verschlossen ist.

This object is achieved by a supercharged internal combustion engine with at least one liquid-cooled turbine of an exhaust gas turbocharger, which is connected to a bearing housing, in which

• The turbine comprises a turbine housing in which at least one impeller mounted on a rotatable shaft is arranged, wherein in the housing at least one exhaust duct leading from an exhaust gas inlet opening extends spirally around the impeller,
• - The bearing housing, which serves to receive the rotatably mounted shaft is connected to a transverse to the shaft mounting flange surface with the turbine housing, and
• The turbine housing has at least one coolant channel arranged in the turbine housing for forming a cooling, wherein this at least one coolant channel extends annularly around the shaft in the housing at least in sections,

and which is characterized in that

• At least one first coolant channel is arranged on the side of the at least one impeller in the turbine housing facing the bearing housing, wherein said at least one first coolant channel is arranged in a flange receiving and forming the mounting flange, is open towards the mounting flange surface and extends from the bearing housing in assembled state is closed like a lid.

According to the invention, at least one first coolant channel is provided in the turbine housing, which is not formed closed, but is open. Only by connecting the turbine housing to the bearing housing on a mounting flange surface is a closed coolant channel formed, through which coolant can be passed without leakage for purposes of cooling.

The open, formed in the turbine housing coolant passage allows the manufacture of the housing as part of a casting process and the formation of a smaller-sized coolant channel on or with the turbine housing. If a first coolant channel is formed by casting integral with the turbine housing as a monolithic casting, the sand used for the cores can be easily and completely removed in a post-processing. Alternatively, a first coolant channel can also be introduced by reworking a cast turbine housing in the mounting flange.

In the present case, the bearing housing in the assembled state also acts as a lid for closing an open first coolant channel.

Thus, the object underlying the invention is achieved, namely provided a supercharged internal combustion engine according to the preamble of claim 1, which is optimized in terms of the material and the cooling of the turbine, d. H. whose turbine has a minimalist cooling of the turbine housing, in which the at least one coolant channel is smaller in size.

The turbine can be equipped with a variable turbine geometry, which allows a further adaptation to the respective operating point of an internal combustion engine by adjusting the turbine geometry or the effective turbine cross section. In this case, adjustable guide vanes for influencing the flow direction are arranged in the inlet region of the turbine. Unlike the vanes of the rotating impeller, the vanes do not rotate with the shaft of the turbine.

If the turbine has a fixed invariable geometry, the vanes are not only stationary, but also completely immovable in the entry area, i. H. rigidly fixed. With a variable geometry, however, the vanes are indeed arranged stationary, but not completely immobile, but rotatable about its axis, so that the flow of the blades can be influenced. The turbine can in principle be executed without any guide.

Embodiments in which the turbine housing is a casting are advantageous. By casting and using appropriate cores, the complex structure of the housing can be formed in one operation, so that subsequently only a post-processing of the housing and the assembly are required to form the turbine.

Embodiments may be advantageous in which the turbine is a double-flow turbine having an inlet region with two exhaust gas inlet openings and two flow channels carrying exhaust gas. The exhaust pipes of the internal combustion engine can be connected in groups with the twin-flow turbine in such a way that the convergence of the exhaust gas flows - if any - takes place downstream of the turbine. If the exhaust pipes are grouped in such a way that the high pressures, in particular the Vorlassstöße, can be obtained, a double-flow turbine is particularly suitable for a burst charge, which also high turbine pressure ratios can be achieved at low speeds. The turbine can also have more than two floods.

Embodiments of the supercharged internal combustion engine in which the at least one first coolant channel extends at a distance from the flow channel leading to the side of the exhaust gas are advantageous. Advantageously, the at least one first coolant channel follows the contour of the exhaust gas-carrying flow channel in order to run as close as possible to the heat source.

The efficiency of the liquid cooling can be significantly increased by the arrangement of the at least one first coolant channel in the immediate vicinity of the impeller compared to an embodiment in which the coolant jacket is not provided adjacent to the impeller and thus to the exhaust stream.

Further advantageous embodiments of the supercharged internal combustion engine according to the subclaims are discussed below.

Embodiments of the supercharged internal combustion engine in which the at least one first coolant channel has a maximum diameter d _{max, 1} with d _{max, 1} ≦ 12 mm are advantageous.

Embodiments of the supercharged internal combustion engine in which the at least one first coolant channel has a maximum diameter d _{max, 1} with d _{max, 1} ≦ 10 mm are advantageous.

Embodiments of the supercharged internal combustion engine in which the at least one first coolant channel has a maximum diameter d _{max, 1} with d _{max, 1} ≦ 8 mm or with d _{max, 1} ≦ 6 mm are advantageous.

The smaller the maximum diameter d _{max, 1 of} a first coolant channel, the more difficult or unlikely it is to be able to form or form this coolant channel in the context of a casting process as a channel integrated in the housing, which is completely surrounded by housing material, so that the inventive design of the first coolant channel wins with decreasing diameter or coolant channel in relevance.

Embodiments of the supercharged internal combustion engine are advantageous in which at least one recess is embedded in the mounting flange surface of the bearing housing, which supplements the at least one first coolant channel arranged in the turbine housing and forms a common coolant channel with this first coolant channel.

With regard to the maximum coolant diameter d _{max, it is} preferable for the common coolant channel that _stated for the first coolant channel.

Embodiments of the supercharged internal combustion engine in which the bearing housing is liquid-cooled are advantageous. In this context, embodiments of the liquid-cooled turbine in which the bearing housing has at least one coolant jacket integrated in the bearing housing to form a cooling are advantageous. An integrated channel is in the context of the present invention, a channel which is completely surrounded by the material of the housing and is formed by this material, wherein the term integrally indicates a monolithic formation.

The minimalist cooling of the turbine housing is supplemented in the present case by a liquid cooling system provided in the bearing housing. The bearing housing serves to receive the shaft of the turbine runner so that cooling of this seat can be advantageous. In addition, the bearing housing is connected to a mounting flange with the turbine housing. If the coolant jacket integrated in the bearing housing is arranged adjacent to and spaced from the mounting flange surface, additional heat is extracted from the turbine housing via the mounting flange surface.

Embodiments of the supercharged internal combustion engine in which at least one second coolant channel is arranged on the side of the at least one impeller facing away from the bearing housing in the turbine housing are advantageous.

Since the at least one second coolant channel is arranged on the side facing away from the bearing housing of the impeller, the at least one exhaust gas leading, spiraling around the impeller flow channel of the turbine present from both sides, d. H. from both sides of the impeller, cooled.

Embodiments of the supercharged internal combustion engine in which the turbine housing is modularly constructed in such a manner that the turbine housing comprises a first housing part facing the bearing housing and a second housing part facing away from the bearing housing are advantageous, wherein the second housing part is connected to the first interface with a cross-section to the shaft Housing part is connected. A modular construction of the turbine housing facilitates the assembly of the turbine, in particular the arrangement of the at least one impeller in the housing, and allows the provision of a second coolant channel in the manner of the first coolant channel.

If a second coolant channel is provided, embodiments of the supercharged internal combustion engine may be advantageous in which the at least one second coolant channel is integrated in the turbine housing, i. H. completely surrounded by the material of the housing and is formed by this material, if this second channel is dimensioned sufficiently large, d. H. has a sufficiently large diameter.

Embodiments of the supercharged internal combustion engine in which the at least one second coolant _channel integrated in the turbine housing therefore has a minimum diameter d _{min, 2, int} with d _{min, 2.int} ≥ _{8 mm} or d _{min, 2.int} ≥ are advantageous in this context 10mm, so that training in the context of a casting process is possible or will.

If the turbine housing has a modular design, embodiments of the supercharged internal combustion engine may also be advantageous in which the separating surface extends through the at least one second coolant channel, as well as embodiments in which the separating surface co-limits the at least one second coolant channel.

In the present case, the at least one second coolant channel is not formed in the turbine housing channel, but in the manner of the first coolant channel.

In this connection, therefore, embodiments of the supercharged internal combustion engine in which the at least one second coolant channel has a maximum diameter d _{max, 2} with d _{max, 2} ≦ 12 mm are also advantageous.

Embodiments of the supercharged internal combustion engine in which the at least one second coolant channel has a maximum diameter d _{max, 2} with d _{max, 2} ≦ 10 mm are also advantageous in this context.

Embodiments of the supercharged internal combustion engine in which the at least one second coolant channel has a maximum diameter d _{max, 2} with d _{max, 2} ≦ 8 mm or with d _{max, 2} ≦ 6 mm are also advantageous in this connection.

If a second coolant channel is provided, embodiments of the supercharged internal combustion engine may be advantageous in which the at least one second coolant channel is connected to the at least one first coolant channel via at least one connecting channel. Then the at least two channels form a coherent coolant circuit.

Preferably, the connecting channel is integrated in the turbine housing. The integration reduces the required space and reduces or eliminates the risk of leakage of coolant by avoiding connections, d. H. by avoiding connections and channel interruptions.

In this context, embodiments of the supercharged internal combustion engine in which the at least one connecting channel is rectilinear, preferably parallel to the shaft, are advantageous.

A rectilinear, in particular parallel to the shaft running, connecting channel can also be introduced by reworking, for example by drilling, in the housing, wherein an open end of the channel can be closed with a plug or can serve as a coolant inlet or outlet.

The connecting channel can be targeted by parts, d. H. Regions of the turbine housing are placed, which are particularly highly thermally stressed, so that the channel not only connects the coolant channels of the turbine housing, but also cools the channel limiting housing material and adjacent to the channel areas.

In this context, embodiments of the supercharged internal combustion engine in which the at least one connecting channel passes through a housing tongue which forms the turbine housing at the end of the at least one exhaust gas flow channel are advantageous. This tongue is thermally stressed.

The cooling can additionally and advantageously be improved in that a pressure gradient is generated between the coolant channels, which in turn increases the velocity in the at least one connecting channel, which leads to an increased heat transfer due to convection. Such a pressure gradient also offers advantages as a driving force for conveying the coolant through the channel.

Advantageous embodiments of the supercharged internal combustion engine, in which the turbine is a radial turbine, d. H. the flow of the blades takes place substantially radially. In this case, essentially radial means that the velocity component in the radial direction is greater than the axial velocity component. The velocity vector of the flow intersects the shaft of the turbine at a right angle if the flow is exactly radial. In this respect, the radial turbine can also be designed in the mixed-flow design, as long as the velocity component in the radial direction is greater than the velocity component in the axial direction.

In order to be able to flow radially to the rotor blades, the inlet region for supplying the exhaust gas is frequently designed as a spiral or worm casing extending all around, so that the inflow of the exhaust gas to the turbine takes place essentially radially.

However, the at least one turbine can also be designed as an axial turbine, in which the velocity component in the axial direction is greater than the velocity component in the radial direction.

A cylinder head of a supercharged internal combustion engine is thermally loaded higher than a conventional cylinder head, which is equipped with an external manifold, and therefore makes increased demands on the cooling, which is why it is advantageous to equip the at least one cylinder head to form a liquid cooling with at least one integrated in the cylinder head coolant jacket.

Embodiments of the supercharged internal combustion engine in which the at least one coolant jacket integrated in the cylinder head is connected to the at least one coolant channel of the turbine housing and / or the at least one coolant jacket of the bearing housing are advantageous. Then, the other required for the formation of a cooling circuit components and aggregates must be provided in principle only in a single copy, since they can be used both for the cooling circuit of the turbine housing and the bearing housing and for the cylinder head, resulting in synergies and significant cost savings, but also brings a weight savings. Thus, preferably only one pump for conveying the coolant and a container for storing the coolant are provided. The heat emitted to the coolant in the cylinder head and in the housings can be withdrawn from the coolant in a common heat exchanger.

Embodiments of the supercharged internal combustion engine in which the at least one first coolant channel and the at least one second coolant channel in a section along the shaft sweeps over or covers a flow channel together only in a limited angular range α, for example with α ≦ 45 °, α ≦ 35, are advantageous °, α ≤ 25 ° or α ≤ 15 °.

In the following the invention is based on two embodiments according to the 1 and 2 described in more detail. Hereby shows:

1 a liquid-cooled and connected to a bearing housing turbine of a first embodiment of the internal combustion engine in a section along the shaft of the turbine runner, and

2 a liquid-cooled and connected to a bearing housing turbine of a second embodiment of the internal combustion engine in a section along the shaft of the turbine runner.

1 shows a liquid-cooled and with a bearing housing 3a connected turbine 1 a first embodiment of the internal combustion engine in a section along the shaft 4a of the turbine runner 4 ,

The turbine 1 is a radial turbine 1a which is a turbine housing 2 and one in this turbine housing 2 arranged and on a rotatable shaft 4a stored impeller 4 includes. The wave 4a itself is in the bearing housing 3a a storage 3 rotatably mounted. The bearing housing 3a is this by means of flange 6 at a cross to the shaft 4a extending mounting flange surface 6a with the turbine housing 2 connected. The associated screw connections are not shown.

So that the exhaust the blades of the impeller 4 can flow radially, is the turbine housing 2 as around the wheel 4 formed spiral housing, in which a outgoing from an exhaust gas inlet opening, exhaust leading flow channel 5 spiral around the wheel 4 extends.

To form a cooling, the turbine housing 2 a first coolant channel 2 B on top of the bearing housing 3a facing side of the impeller 4 in the turbine housing 2 is arranged and in the housing 2 at least in sections annularly around the shaft 4a extends. This first coolant channel 2 B is in which the mounting flange 6a receiving and training flange 6 arranged, to the mounting flange surface 6a open and is from the bearing housing 3a closed in the assembled state lid. The open training of the channel 2 B allows the first channel 2 B smaller than when casting to dimension, ie provided with a small diameter in order to reduce the cooling capacity.

The liquid cooling of the turbine is supplemented 1 through a second coolant channel 2c Standing on the bearing housing 3a opposite side of the impeller 4 in the turbine housing 2 is arranged so that the exhaust leading, spiraling around the impeller 4 extending flow channel 5 the turbine 1 on both sides of the impeller 4 is cooled.

In the present case, the second coolant channel 2c one in the turbine housing 2 integrated channel 2c made entirely of the material of the case 2 is surrounded, ie fully from the housing 2 is trained. For reasons of casting technology, this requires a sufficiently large diameter of the second channel 2c ,

The first coolant channel 2 B is with the turbine housing 2 integrated second coolant channel 2 B via connection channel 7 connected in the turbine housing 2 integrated connection channel 7 at the in 1 illustrated embodiment in a straight line and parallel to the shaft 4a runs.

2 shows a liquid-cooled and with a bearing housing 3a connected turbine 1 a second embodiment of the internal combustion engine in a section along the shaft 4a of the turbine runner 4 , It should only the differences to the in 1 Otherwise, reference will be made to FIG 1 and the corresponding description. The same reference numerals have been used for the same components.

Unlike the in 1 illustrated embodiment, the turbine housing 2 at the in 2 illustrated turbine 1 modular in the way that the turbine housing 2 a first the bearing housing 3a facing housing part 2a' and a second one from the bearing housing 3a remote housing part 2a'' comprising, wherein the second housing part 2a'' at a cross to the shaft 4 extending separation surface 6b with the first housing part 2a' connected is.

The modular design of the turbine housing 2 allows the provision of a second coolant channel 2c in the manner of the first coolant channel 2 B , This allows the second channel 2c smaller dimensioned, ie to be provided with a small diameter in order to reduce the cooling capacity. In the present case, the separation surface runs 6b through this second coolant channel 2c ,

LIST OF REFERENCE NUMBERS

1

 turbine

1a

 radial turbine

2

 turbine housing

2a'

 first housing part

2a''

 second housing part

2 B

 first coolant channel

2c

 second coolant channel

3

 storage

3a

 bearing housing

4

 Wheel

4a

 wave

5

 Exhaust gas leading flow channel

6

 flange

6a

 Mounting flange

6b

 interface

7

 connecting channel

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 102008011257 A1 [0014]
• EP 1384857 A2 [0015]
• DE 102007017973 A1 [0016]

Claims (18)

Supercharged internal combustion engine with at least one liquid-cooled turbine ( 1 ) of an exhaust gas turbocharger, which with a bearing housing ( 3a ), in which - the turbine ( 1 ) a turbine housing ( 2 ), in which at least one on a rotatable shaft ( 4a ) stored impeller ( 4 ) is arranged, wherein in the housing ( 2 ) at least one outgoing from an exhaust gas inlet opening, exhaust gas leading flow channel ( 5 ) spirally around the impeller ( 4 ), - the bearing housing ( 3a ), which for receiving the rotatably mounted shaft ( 4a ), at one transverse to the shaft ( 4a ) mounting flange surface ( 6a ) with the turbine housing ( 2 ), and - the turbine housing ( 2 ) for forming a cooling at least one in the turbine housing ( 2 ) arranged coolant channel ( 2 B . 2c ), said at least one coolant channel ( 2 B . 2c ) in the housing ( 2 ) at least in sections annularly around the shaft ( 4a ), characterized in that - at least one first coolant channel ( 2 B ) on the bearing housing ( 3a ) facing side of the at least one impeller ( 4 ) in the turbine housing ( 2 ), wherein said at least one first coolant channel ( 2 B ) in one the mounting flange surface ( 6a ) receiving and forming flange ( 6 ), to the mounting flange surface ( 6a ) is open and from the bearing housing ( 3a ) is closed like a lid in the assembled state. Supercharged internal combustion engine according to claim 1, characterized in that the at least one first coolant channel ( 2 B ) has a maximum diameter d _{max, 1} with d _{max, 1} ≤ 12mm. Supercharged internal combustion engine according to claim 1 or 2, characterized in that the at least one first coolant channel ( 2 B ) has a maximum diameter d _{max, 1} with d _{max, 1} ≤ 10mm. Supercharged internal combustion engine according to one of the preceding claims, characterized in that the at least one first coolant channel ( 2 B ) has a maximum diameter d _{max, 1} with d _{max, 1} ≤ 8mm. Supercharged internal combustion engine according to one of the preceding claims, characterized in that in the mounting flange ( 6a ) of the bearing housing ( 3a ) at least one recess is embedded, which the at least one first in the turbine housing ( 2 ) arranged coolant channel ( 2 B ) and with this first coolant channel ( 2 B ) forms a common coolant channel. Supercharged internal combustion engine according to one of the preceding claims, characterized in that the bearing housing ( 3a ) for forming a cooling at least one in the bearing housing ( 3a ) has integrated coolant jacket. Supercharged internal combustion engine according to one of the preceding claims, characterized in that at least one second coolant channel ( 2c ) on the bearing housing ( 3a ) facing away from the at least one impeller ( 4 ) in the turbine housing ( 2 ) is arranged. Supercharged internal combustion engine according to one of the preceding claims, characterized in that the turbine housing ( 2 ) modular in the way that the turbine housing ( 2 ) a first the bearing housing ( 3a ) facing housing part ( 2a' ) and a second one from the bearing housing ( 3a ) facing away from the housing part ( 2a'' ), wherein the second housing part ( 2a'' ) on a transverse to the shaft ( 4a ) separating surface ( 6b ) with the first housing part ( 2a' ) connected is. Supercharged internal combustion engine according to claim 7 or 8, characterized in that the at least one second coolant channel ( 2c ) in the turbine housing ( 2 ) is integrated. Supercharged internal combustion engine according to claim 9, characterized in that the at least one in the turbine housing ( 2 ) integrated second coolant channel ( 2c ) has a minimum diameter d _{min, 2, int} with d _{min, 2, int} ≥ 8mm. Supercharged internal combustion engine according to claim 8, characterized in that the separating surface ( 6b ) through the at least one second coolant channel ( 2c ) runs. Supercharged internal combustion engine according to claim 8, characterized in that the separating surface ( 6b ) the at least one second coolant channel ( 2c ) mitbegrenzt. Supercharged internal combustion engine according to claim 11 or 12, characterized in that the at least one second coolant channel ( 2c ) has a maximum diameter d _{max, 2} with d _{max, 2} ≤ 12mm. Supercharged internal combustion engine according to one of claims 11 to 13, characterized in that the at least one second coolant channel ( 2c ) has a maximum diameter d _{max, 2} with d _{max, 2} ≤ 10mm. Supercharged internal combustion engine according to one of claims 11 to 14, characterized in that the at least one second coolant channel ( 2c ) has a maximum diameter d _{max, 2} with d _{max, 2} ≤ 8mm. Supercharged internal combustion engine according to one of claims 7 to 15, characterized in that the at least one second coolant channel ( 2c ) with the at least one first coolant channel ( 2 B ) via at least one connection channel ( 7 ) connected is. Supercharged internal combustion engine according to claim 16, characterized in that the at least one connecting channel ( 7 ) is rectilinear, preferably parallel to the shaft ( 4a ) runs. Supercharged internal combustion engine according to one of the preceding claims, characterized in that the turbine ( 1 ) a radial turbine ( 1a ).

Images