DE102013203376A1 - Liquid-cooled radial-flow turbine for exhaust gas turbocharger of motor car, has bearing housing comprising coolant cladding integrated in bearing housing and arranged adjacent and spaced apart to assembly flange surface in flange - Google Patents

Abstract

The turbine has a coolant channel (2b) integrated in a turbine housing (2a). The coolant channel extends at a rotatably mounted shaft (4a) in the turbine housing and is arranged on a side of a turbine running wheel (4) turned away from a bearing housing (3a). The bearing housing for refrigeration comprises a coolant cladding (3b) integrated in the bearing housing. The coolant cladding is arranged adjacent and spaced apart to an assembly flange surface (6a) in a flange (6). The flange holds the assembly flange surface. The bearing housing is connected with the turbine housing. The turbine housing is designed as a spiral housing.

Description

• – die Radialturbine ein Turbinengehäuse, in dem ein auf einer drehbaren Welle gelagertes Laufrad angeordnet ist, umfasst, wobei sich im Gehäuse ausgehend von einer Abgaseintrittsöffnung ein 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 integrierten Kühlmittelkanal aufweist, wobei dieser mindestens eine Kühlmittelkanal sich im Gehäuse zumindest abschnittsweise ringförmig um die Welle erstreckt und auf der dem Lagergehäuse abgewandten Seite des Laufrades angeordnet ist.

The invention relates to a liquid-cooled radial turbine, which is connected to a bearing housing, in which

• The radial turbine comprises a turbine housing, in which an impeller mounted on a rotatable shaft is arranged, wherein in the housing, starting from an exhaust gas inlet opening, an exhaust-carrying flow channel spirally extends 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 integrated in the turbine housing coolant channel, said at least one coolant channel extends at least partially annularly around the shaft in the housing and is arranged on the side facing away from the bearing housing of the impeller.

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 often fed to a radial turbine, for example, the turbine of an exhaust gas turbocharger, and optionally passed through one or more exhaust aftertreatment systems.

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. In particular, when it is considered that a close-coupled arrangement of the turbine leads to a relatively large-sized, voluminous housing. Because the connection of turbine and cylinder head by means of flange and screws requires a large turbine inlet area due to the limited space available; also due to 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 materials.

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.

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 integral part 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. That through the casing extended housing then encloses 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 the water usually used, 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 withdrawn from the coolant 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 to contribute 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. 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 require extensive cooling of the recirculating exhaust gas, ie. H. a compression of the exhaust gas by cooling, make 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.

In view of the above, it is the object of the present invention to provide a liquid-cooled radial turbine according to the preamble of claim 1, which is optimized in terms of material and cooling.

• – die Radialturbine ein Turbinengehäuse, in dem ein auf einer drehbaren Welle gelagertes Laufrad angeordnet ist, umfasst, wobei sich im Gehäuse ausgehend von einer Abgaseintrittsöffnung ein 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 integrierten Kühlmittelkanal aufweist, wobei dieser mindestens eine Kühlmittelkanal sich im Gehäuse zumindest abschnittsweise ringförmig um die Welle erstreckt und auf der dem Lagergehäuse abgewandten Seite des Laufrades angeordnet ist, und die dadurch gekennzeichnet ist, dass
• – das Lagergehäuse zur Ausbildung einer Kühlung mindestens einen im Lagergehäuse integrierten Kühlmittelmantel aufweist, wobei dieser mindestens eine Kühlmittelmantel benachbart und beabstandet zur Montage-Flanschfläche in einem die Montage-Flanschfläche aufnehmenden und ausbildenden Flansch angeordnet ist.

This object is achieved by a liquid-cooled radial turbine, which is connected to a bearing housing, in which

• The radial turbine comprises a turbine housing, in which an impeller mounted on a rotatable shaft is arranged, wherein in the housing, starting from an exhaust gas inlet opening, an exhaust-carrying flow channel spirally extends 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 integrated in the turbine housing coolant channel, said at least one coolant channel in the housing at least partially annularly extends around the shaft and is arranged on the side facing away from the bearing housing of the impeller, and which is characterized in that
• - The bearing housing to form a cooling at least one integrated coolant jacket in the bearing housing, said at least one coolant jacket adjacent and spaced from the mounting flange in a mounting flange receiving and forming flange is arranged.

According to the invention, no coolant jacket is provided in the turbine housing, which completely envelopes the rotor, d. H. encased, but only a coolant channel, which extends in the housing - at least in sections - annularly around the shaft.

This minimalist cooling of the turbine housing is supplemented by a liquid cooling system provided in a bearing housing. The bearing housing, which serves to receive the shaft of the turbine runner, is connected to the turbine housing at a mounting flange surface, so that the coolant jacket integrated in the bearing housing and spaced from the mounting flange surface also extracts heat from the turbine housing via the mounting flange surface.

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

A possible large-scale sheathing of the impeller with coolant and thus the largest possible heat dissipation are not sought according to the invention. Rather, the cooling capacity is deliberately kept within limits by only a coolant channel is provided to form a cooling in the turbine housing itself.

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 according to the invention, namely gray cast iron or steel casting or the like. Embodiments in which the turbine is made of gray cast iron are advantageous.

On the one hand, the concept according to the invention makes it possible to dispense with materials which are highly thermally resistant, in particular containing nickel, for producing the turbine housing, since according to the invention the turbine is also provided with cooling which ensures a reduction in temperature and reduces the thermal load on the material, which is why high-temperature-resistant materials are dispensable.

On the other hand, the cooling capacity is not dimensioned so extensive that thermally only slightly resilient materials, such as aluminum, could be used.

The procedure according to the invention makes the use of expensive materials dispensable without having to dissipate excessively large amounts of heat in connection with the cooling of the turbine.

Thus, the object underlying the invention is achieved, namely to provide a liquid-cooled radial turbine according to the preamble of claim 1, which is optimized in terms of the material and the cooling.

The turbine is designed according to the invention as 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.

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 also be advantageous in which the turbine is a double-flow turbine having an inlet region with two exhaust gas inlet openings and two exhaust gas flow channels, wherein the exhaust lines of the internal combustion engine are connected in groups with the twin-flow turbine in such a way that the merging of the exhaust gas streams if any - done 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 radial turbine used 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, 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. The vanes are stationary, but not completely immobile, but rotatable about its axis, so that the flow of the blades can be influenced.

Further advantageous embodiments of the liquid-cooled radial turbine according to the subclaims are discussed below.

Embodiments of the liquid-cooled radial turbine in which the at least one coolant channel extends at a distance from the flow channel leading to the side of the exhaust gas and at least over a predefinable angular range are advantageous. Advantageously, the at least one integrated coolant channel follows - at least partially - the contour of the exhaust gas leading flow channel to extend as close to the heat source.

However, embodiments of the liquid-cooled radial turbine may also be advantageous in which the at least one coolant channel extends circumferentially around and at a distance from the flow channel leading to the exhaust gas. Namely, at the outer circumference of the flow channel, the diversion of the exhaust gas takes place in the circumferential direction, which is why in this region of the exhaust side boundary wall, the thermal load due to heat convection is greatest.

Also advantageous embodiments of the liquid-cooled radial turbine, in which the largest outer radial distance of the at least one coolant channel of the shaft is greater than the largest outer radial distance of the exhaust gas flow channel leading from the shaft.

Embodiments of the liquid-cooled radial turbine in which the at least one coolant jacket integrated in the bearing housing extends along the impeller and is aligned, are advantageous. H. corresponds with the contour of the impeller.

This is advantageous because a large-area coolant jacket in the immediate vicinity of the impeller and the associated cooling of the exhaust gas during expansion prevents direct heat input into wide housing parts and removes heat via the mounting flange surface.

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

The radial turbine according to the invention is particularly suitable for an exhaust gas turbocharger of an internal combustion engine, in which the at least one turbine is thermally particularly heavily loaded due to the high exhaust gas temperatures and therefore cooling of the turbine is particularly advantageous.

Also advantageous are embodiments in which the radial turbine is part 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. With the same vehicle boundary conditions can be so Shift load collective to higher loads where specific fuel consumption is lower.

Compared to a mechanical supercharger, the advantage of an exhaust gas turbocharger is that there is no mechanical connection to the power transmission between the supercharger and the internal combustion engine or is required. 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.

Embodiments in which the exhaust lines of the cylinders merge to form at least one integrated exhaust manifold within the cylinder head to form at least one overall exhaust gas line are advantageous.

It should be noted that, in principle, the aim is to arrange the turbine, in particular the turbine of an exhaust gas turbocharger, as close as possible to the outlet of the cylinders in order to make optimum use of the exhaust gas enthalpy of the hot exhaust gases, which is largely determined by the exhaust gas pressure and the exhaust gas temperature and to ensure a fast response of the turbine or the turbocharger. Furthermore, the path of the hot exhaust gases to the various exhaust aftertreatment systems should be as short as possible, so that the exhaust gases are given little time to cool and the exhaust aftertreatment systems reach their operating temperature or light-off as soon as possible, especially after a cold start of the engine.

To achieve this goal, it makes sense to bring the exhaust pipes together to form at least one integrated exhaust manifold within the cylinder head. First, the line volume, i. H. the exhaust volume of the exhaust pipes upstream of the turbine, reduced, so that the response of the turbine is improved. On the other hand, the shortened exhaust pipes also lead to a lower thermal inertia of the exhaust system upstream of the turbine, so that the temperature of the exhaust gases at the turbine inlet increases, which is why the enthalpy of the exhaust gases at the entrance of the turbine is higher.

The merging of the exhaust pipes within the cylinder head also allows a dense packaging of the drive unit.

However, such a trained cylinder head is thermally more heavily loaded than a conventional cylinder head, which is equipped with an external manifold, and therefore makes increased demands on the cooling.

The heat released during combustion by the exothermic, chemical conversion of the fuel is partially dissipated via the walls delimiting the combustion chamber to the cylinder head and the cylinder block and partly via the exhaust gas flow to the adjacent components and the environment. In order to keep the thermal load of the cylinder head within limits, a part of the introduced into the cylinder head heat flow must be withdrawn from the cylinder head again.

Due to the much higher heat capacity of liquids compared to air can be dissipated with liquid cooling much larger amounts of heat than with air cooling, which is why cylinder heads of the type in question are advantageously equipped with a liquid cooling.

The liquid cooling requires the equipment of the cylinder head with at least one coolant jacket, d. H. the arrangement of the coolant through the cylinder head leading coolant channels, which causes a complex structure of the cylinder head construction. In this case, the mechanically and thermally highly stressed cylinder head is weakened by the introduction of the coolant channels on the one hand in its strength. On the other hand, the heat does not have to be directed to the cylinder head surface, as in the case of air cooling, in order to be dissipated. The heat is already released inside the cylinder head to the coolant. The coolant is conveyed by means of a pump arranged in the cooling circuit, so that it circulates in the coolant jacket. The heat given off to the coolant is removed in this way from the interior of the cylinder head and removed from the coolant in a heat exchanger again.

Preferably, the cooling capacity should be so high that on a Anfettung (λ <1) for lowering the exhaust gas temperatures, as for example in the EP 1 722 090 A2 is described, can be dispensed with.

A liquid cooling proves to be particularly advantageous in turbocharged engines, since the thermal load of turbocharged engines compared to conventional internal combustion engines is significantly higher.

It follows from the above that embodiments are advantageous in which the cylinder head is equipped to form a liquid cooling with at least one coolant jacket integrated in the cylinder head.

Embodiments in which the at least one coolant jacket integrated in the cylinder head is advantageous with the at least one embodiment are advantageous Coolant channel of the turbine housing and / or the at least one coolant jacket of the bearing housing is connected. 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 as well as 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.

In internal combustion engines, which are equipped to form a liquid cooling with a coolant circuit, in principle embodiments are advantageous in which the at least one integrated in the bearing housing coolant jacket is connected to the coolant circuit of the internal combustion engine. The coolant jacket of the bearing housing can then be supplied with coolant via the cylinder head, so that no further coolant supply and discharge openings must be provided and additional coolant lines can be dispensed with, in particular if the coolant jacket integrated in the bearing housing is supplied with coolant via coolant channel integrated in the turbine housing . vice versa.

Therefore, embodiments of the liquid-cooled radial turbine in which the at least one coolant channel integrated in the turbine housing is connected to the at least one coolant jacket integrated in the bearing housing are also advantageous.

Embodiments of the liquid-cooled radial turbine in which the at least one coolant channel integrated in the turbine housing is connected to the at least one coolant jacket integrated in the bearing housing via at least one connecting channel, wherein the connecting channel preferably runs parallel to the shaft, are advantageous.

Preferably, the connecting channel is integrated in the turbine housing or the bearing 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.

A rectilinear, in particular parallel to the shaft running, connecting channel can also be introduced by post-processing, such as 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 or bearing housing are placed, which are particularly highly thermally stressed, so that the channel not only connects the coolant channel of the turbine housing with the coolant jacket of the bearing housing, but also cools the channel limiting housing material and adjacent to the channel areas.

This cooling can additionally and advantageously be improved in that a pressure gradient is generated between the coolant channel and the coolant jacket, 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.

In this context, embodiments of the liquid-cooled radial turbine in which the at least one connecting channel passes through a housing tongue which forms the turbine housing at the end of the exhaust gas flow channel are advantageous. This tongue is thermally stressed on both sides of the hot exhaust gas flow, namely at the end of the flow channel and upstream of the flow channel in the inlet region of the turbine, wherein the free end of the tongue facing the impeller and therefore is also acted upon with hot exhaust gas.

Embodiments of the liquid-cooled radial turbine in which the flange has a diameter D _Fl with D _Fl ≥ 70 mm are advantageous.

Embodiments of the liquid-cooled radial turbine in which the flange has a diameter D _Fl with D _Fl ≥ 85 mm are advantageous.

The flange of the two above embodiments has a significantly larger diameter than a flange according to the prior art, which has a diameter D _Fl ≈ 40 ... 60mm.

This supports the function of the bearing housing as additional cooling for the turbine housing. The extraction of heat from the turbine housing via mounting flange surface is namely increased by increasing the heat transfer surface.

Embodiments of the liquid-cooled radial turbine in which at least one recess is embedded in the mounting flange surface of the turbine housing are advantageous.

In the present case, at least one recess is provided in the turbine housing, which acts as a thermal barrier and impedes direct heat flow between the bearing housing and the turbine housing and thereby reduces or specifically directs the heat flow, namely around the at least one recess. On the structural design of the at least one recess, in particular the shape and the arrangement, influence can be made on the heat flows and thus on the temperature distribution in the housing. Thus, a plurality of recesses can be arranged on a ring around the shaft of the impeller around. The fact that the recess is open to the mounting flange surface simplifies the formation, i. H. the production of the recess, which can be formed with the housing in the casting process or later by reworking.

The at least one recess leads to a reduced flow of heat from housing areas, which lie between the flow channel and the recess. At the same time, the heat flow increases over passages leading past the recess, for example from housing areas which extend on an outer circumference circumferentially around and at a distance from the exhaust gas-carrying flow channel. It is precisely these housing areas, which are particularly thermally stressed due to the permanent deflection of the exhaust stream at the outer periphery of the flow channel.

The provision of at least one recess also contributes to a homogenization of the temperature distribution in the housing and thus to a reduction of the temperature gradient usually occurring in the housing according to the prior art, without a plurality of coolant channels provided or the coolant channel would have to be designed as a large-area coolant jacket , which would be associated with unfavorably large dissipated amounts of heat, which are basically considered problematic.

Embodiments of the liquid-cooled radial turbine in which the at least one recess in the turbine housing faces the at least one coolant jacket integrated in the bearing housing-viewed parallel to the shaft-are advantageous here. Seen parallel to the shaft means in this regard in the direction of a parallell of the shaft.

The at least one recess can be filled during assembly with air or other material.

Embodiments of the liquid-cooled radial turbine in which at least one recess is embedded in the mounting flange surface of the bearing housing are advantageous.

Embodiments of the liquid-cooled radial turbine in which the at least one recess in the bearing housing faces the at least one coolant jacket integrated in the bearing housing, viewed parallel to the shaft, are also advantageous.

The statements made in connection with the at least one recess arranged in the turbine housing apply analogously.

In the following the invention is based on an embodiment according to 1 described in more detail. Hereby shows:

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

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

The turbine 1 is a radial turbine 2 which is a turbine housing 2a and one in this turbine housing 2a 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 2a 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 2a as around the wheel 4 running spiral housing formed, in which an exhaust gas leading flow channel 5 starting from an exhaust gas inlet opening spirally around the impeller 4 extends.

To form a cooling, the turbine housing 2a an integrated coolant channel 2 B on, in the housing 2a ring around the shaft 4a extends. The coolant channel 2 B is on the bearing housing 3a opposite side of the impeller 4 arranged.

The bearing housing 3a has to form a cooling one in the bearing housing 3a integrated coolant jacket 3b adjacent to and spaced from the mounting flange surface 6a in the flange 6 is arranged and also the additional cooling of the turbine housing 2a serves.

The in the turbine housing 2a integrated coolant channel 2 B is via connection channel 7 with the in the bearing housing 3a integrated coolant jacket 3b connected, where in the housings 2a . 3a integrated connection channel 7 at the in 1 illustrated embodiment in a straight line and parallel to the shaft 4a runs.

The connection channel 7 is present by drilling in the housing 2a . 3a been introduced. The open end of the channel 7 was with a stopper 7a closed to prevent the escape of coolant, ie leakage safely.

Into the mounting flange surface 6a of the turbine housing 2a are two recesses 2c in the form of bags 2c let in, which is the coolant jacket 3b of the bearing housing 3a opposite, act as a thermal barrier, to a reduced heat flow from housing areas between the flow channel 5 and the recesses 2c lead and in particular the heat flow from the housing areas on the outer circumference of the flow channel 5 about one at the recesses 2c Promote passing web, ie enlarge.

LIST OF REFERENCE NUMBERS

1

turbine

2

radial turbine

2a

turbine housing

2 B

Coolant channel

2c

Recess, pocket

3

storage

3a

bearing housing

3b

Coolant jacket

4

Wheel

4a

wave

5

Exhaust gas leading flow channel

6

flange

6a

Mounting flange

7

connecting channel

7a

plug

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 [0010]
• EP 1384857 A2 [0011]
• DE 102007017973 A1 [0012]
• EP 1722090 A2 [0059]

Claims (16)

Liquid-cooled radial turbine ( 2 ) with a bearing housing ( 3a ), in which - the radial turbine ( 2 ) a turbine housing ( 2a ) in which one on a rotatable shaft ( 4a ) stored impeller ( 4 ) is arranged, wherein in the housing ( 2a ) starting from an exhaust gas inlet opening an 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 ( 2a ), and - the turbine housing ( 2a ) for forming a cooling at least one in the turbine housing ( 2a ) integrated coolant channel ( 2 B ), said at least one coolant channel ( 2 B ) in the housing ( 2a ) at least in sections annularly around the shaft ( 4a ) and on the bearing housing ( 3a ) facing away from the impeller ( 4 ), Is arranged, characterized in that - the bearing housing ( 3a ) for forming a cooling at least one in the bearing housing ( 3a ) integrated coolant jacket ( 3b ), wherein this at least one coolant jacket ( 3b ) adjacent and spaced from the mounting flange surface ( 6a ) in one the mounting flange surface ( 6a ) receiving and forming flange ( 6 ) is arranged. Liquid-cooled radial turbine ( 2 ) according to claim 1, characterized in that the at least one coolant channel ( 2 B ) spaced apart from and laterally from the exhaust gas leading flow channel ( 5 ). Liquid-cooled radial turbine ( 2 ) according to claim 1 or 2, characterized in that the largest outer radial distance of the at least one coolant channel ( 2 B ) from the wave ( 4a ) is greater than the largest outer radial distance of the exhaust gas carrying flow channel ( 5 ) from the wave ( 4a ). Liquid-cooled radial turbine ( 2 ) according to one of the preceding claims, characterized in that the at least one in the bearing housing ( 3a ) integrated coolant jacket ( 3b ) along the impeller ( 4 ) extends and is aligned. Liquid-cooled radial turbine ( 2 ) according to one of the preceding claims, characterized in that the at least one in the bearing housing ( 3a ) integrated coolant jacket ( 3b ) is connected to a coolant circuit of an internal combustion engine. Liquid-cooled radial turbine ( 2 ) According to one of the preceding claims, characterized in that the at least one (in the turbine housing 2a ) integrated coolant channel ( 2 B ) with the at least one in the bearing housing ( 3a ) integrated coolant jacket ( 3b ) connected is. Liquid-cooled radial turbine ( 2 ) according to claim 6, characterized in that the at least one in the turbine housing ( 2a ) integrated coolant channel ( 2 B ) with the at least one in the bearing housing ( 3a ) integrated coolant jacket ( 3b ) via at least one connection channel ( 7 ) connected is. Liquid-cooled radial turbine ( 2 ) according to claim 7, characterized in that the at least one connecting channel ( 7 ) is rectilinear, preferably parallel to the shaft ( 4a ) runs. Liquid-cooled radial turbine ( 2 ) according to claim 7 or 8, characterized in that the at least one connecting channel ( 7 ) passes through a housing tongue which the turbine housing ( 2a ) at the end of the exhaust gas leading flow channel ( 5 ) trains. Liquid-cooled radial turbine ( 2 ) according to one of the preceding claims, characterized in that the flange ( 6 ) has a diameter D _Fl with D _Fl ≥ 70mm. Liquid-cooled radial turbine ( 2 ) according to one of the preceding claims, characterized in that the flange ( 6 ) has a diameter D _Fl with D _Fl ≥ 85mm. Liquid-cooled radial turbine ( 2 ) according to one of the preceding claims, characterized in that in the mounting flange ( 6a ) of the turbine housing ( 2a ) at least one recess ( 2c ) is admitted. Liquid-cooled radial turbine ( 2 ) According to claim 12, characterized in that the (at least one recess 2c ) in the turbine housing ( 2a ) the at least one in the bearing housing ( 3a ) integrated coolant jacket ( 3b ) - parallel to the shaft ( 4a ) - is opposite. Liquid-cooled radial turbine ( 2 ) According to one of the preceding claims, characterized in that (in the mounting flange 6a ) of the bearing housing ( 3a ) is recessed at least one recess. Liquid-cooled radial turbine ( 2 ) according to claim 14, characterized in that the at least one recess in the bearing housing ( 3a ) the at least one in the bearing housing ( 3a ) integrated coolant jacket ( 3b ) - parallel to the shaft ( 4a ) - is opposite. Liquid-cooled radial turbine ( 2 ) According to one of the preceding claims, characterized in that the radial turbine ( 2 ) Is part of an exhaust gas turbocharger.

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