DE102012001237A1 - Turbine for supercharger, has flow channel that is limited partly by one of the housing portions and partly by the insert element - Google Patents

Abstract

The turbine (10) has a turbine housing (12) provided with a flow channel (22) which is flowed through by exhaust gas. The exhaust gas is passed to a turbine wheel of the turbine through flow channel. The turbine housing is formed by two axially adjoining of housing portions (14,16). An insert element (24) is located between the housing portions. The flow channel is limited partly by one of the housing portions and partly by the insert element.

Description

The invention relates to a turbine for an exhaust gas turbocharger according to the preamble of patent claim 1.

The DE 10 2009 050 951 A1 discloses a turbine for an exhaust gas turbocharger with a turbine housing. The turbine housing has a receiving space in which a turbine wheel of the turbine is rotatably received about an axis of rotation relative to the turbine housing. The turbine housing further has at least one flow channel through which exhaust gas can flow and via which the exhaust gas can be fed to the turbine wheel.

In the turbine housing, a guide grid is arranged with guide vanes, which divert the exhaust gas flowing to the turbine wheel. Thus, the exhaust gas can flow to the turbine wheel aerodynamically.

The turbine also includes a so-called axial slide, which has a female-like receptacle. In the receptacle, the guide vanes are at least partially receivable, so that the guide vanes are covered on both sides in the radial direction of the turbine.

In order to ensure a high degree of functional reliability of the axial slide, so-called function gaps are to be provided between the axial slide and the guide vanes so that jamming of the axial slide with the guide vanes and / or other malfunctions does not occur.

Further, from the general state of the art, turbines with turbine housings are known in which a respective guide is arranged. The guide comprises rotatable vanes about a respective axis of rotation relative to the turbine housing. The vanes are arranged in a flow channel and can divert the exhaust gas flowing to the turbine wheel. In order to avoid jamming and / or other malfunction of the guide vanes, function gaps between the guide vanes and the flow passage bounding walls should also be provided.

The function gaps are therefore particularly necessary since the guide vanes and the turbine housing or the walls delimiting the flow channel thermally deform, in particular expand, as a result of being exposed to relatively high temperatures of the hot exhaust gas. This can lead to different, thermal deformations.

It has been shown that, due to the functional gaps, so-called secondary radiation losses can occur. The exhaust gas may flow past the functional gaps past the vanes, so that the exhaust gas is not diverted from the vanes. The exhaust then flows at least substantially non-directionally on the turbine wheel, affecting the efficient operation of the turbine. Furthermore, the known turbines on a relatively high complexity.

It is therefore an object of the present invention to provide a turbine for an exhaust gas turbocharger, which has a very low complexity and a particularly efficient operation.

This object is achieved by a turbine for an exhaust gas turbocharger having the features of patent claim 1. Advantageous embodiments with expedient and non-trivial developments of the invention are specified in the remaining claims.

Such a turbine for an exhaust gas turbocharger comprises a turbine housing. The turbine housing has at least one flow channel through which exhaust gas can flow. The exhaust gas can be supplied to a turbine wheel of the turbine via the flow channel.

According to the invention, the turbine housing comprises at least two axially adjoining and interconnected housing parts, between which an insert element is arranged at least in regions. The flow channel is partially bounded by at least one of the housing parts and partially by the insert element. The at least two-part turbine housing and the insert element have a particularly advantageous deformation behavior during operation of the turbine, in which the flow channel is traversed by hot exhaust gas, for example, of an internal combustion engine assigned to the turbine. Due to the at least two-part design and the insert element, there are only very small, thermally induced deformations of the turbine. This is a particularly efficient operation of the turbine benefit because, for example, function gaps between relatively movable elements of the turbine can be kept particularly low. Furthermore, the turbine according to the invention can be designed with only a very small complexity, which leads to a very high functional reliability and at low cost of the turbine. In particular, it is possible to keep down a cost for producing the housing parts and the insert element, in particular with regard to tolerances. This results in particularly low production costs for the turbine housing and the insert element.

The high functional reliability of the turbine enables the efficient operation of the turbine over a long service life and at high exhaust gas temperatures. In particular, the risk of cracking of the turbine housing is particularly low even at very high temperatures.

Preferably, the insert element formed separately from the housing parts is at least partially spaced in the radial direction of at least one of the housing parts. As a result, during use of the turbine, the insert element can expand and contract at least virtually unhindered, in particular in the radial direction, and thus move relative to the housing parts, without resulting in tension and resulting damage and / or malfunction of the turbine.

In a particularly advantageous embodiment of the invention, the insert element is clamped between the housing parts. As a result, a fixed and at the same time simple and therefore inexpensive attachment of the separately formed from the housing parts insert element is realized.

In a further advantageous embodiment of the turbine, an adjusting device is provided with at least one adjusting element movable relative to the housing parts, by means of which a flow cross-section, via which the exhaust gas can be fed to the turbine wheel, is adjustable. In other words, the flow cross-section can be widened or narrowed by moving the adjusting element relative to the housing parts. As a result, the Aufstauverhalten the turbine of the invention can be variably adjusted. The turbine is thus variable and adjustable to different mass flows of the exhaust gas and can be operated efficiently both at relatively high exhaust gas mass flows and in contrast to low exhaust gas mass flows.

Preferably, the adjusting element is displaceable in the axial direction of the turbine relative to the housing parts and the insert element. As a result, the adjusting device has a particularly high robustness against high temperatures and thus a high degree of functional reliability. This ensures efficient operation of the turbine over a long service life.

In a further advantageous embodiment, at least one guide device with guide elements, in particular guide vane, is provided, by means of which the exhaust gas to be supplied to the turbine wheel can be diverted. As a result of the diversion or deflection of the exhaust gas by means of the guide elements, the exhaust gas can flow to the turbine wheel in at least one aerodynamic angle and thereby drive efficiently.

The guide elements are arranged distributed in the circumferential direction of the turbine wheel over its circumference. Preferably, the guide elements are immovable relative to the turbine housing and the insert element. This keeps the complexity of the turbine particularly low.

To realize a particularly low complexity, a particularly high robustness and thus a very high functional reliability of the turbine is provided in one embodiment of the invention that the adjustment in an adjustment relative to the guide elements movable and at least predominantly, in particular entire adjustment range without coverage to the Is guiding elements. With other maintenance, the guide elements are covered in the radial direction of the turbine by means of the adjusting element neither on only one side nor on two opposite sides and not received in the adjusting element. Thus, functional gaps between the adjusting element and the guide elements can be avoided. Furthermore, the risk of jamming and / or other malfunction of the adjustment is particularly low. In the turbine according to the invention also only a very low wear, in particular the adjustment is realized. Another advantage is that the adjusting device and in particular the adjusting element can be produced in a timely and cost-effective manner.

In a further embodiment of the invention, the adjusting element in its maximum cross-section of the flow cross-section is at least indirectly on a the adjusting element facing end side of the guide, in particular the guide elements on. Since the guide elements are not covered in the radial direction of the turbine by means of the adjusting element and are not accommodated in the adjusting element, the at least substantially entire exhaust gas flows via the guide elements and is diverted or deflected by the latter. At least essentially no exhaust gas can flow between the adjusting element and the guide elements. This leads to a particularly efficient operation of the turbine.

In a further advantageous embodiment, a cover element adjoins the guide elements in the axial direction, which projects beyond the guide elements in the radial direction toward the turbine wheel and / or away from the turbine wheel. As a result, very favorable flow conditions for the exhaust gas are created, resulting in an efficient operation of the turbine.

Preferably, the guide is formed separately from the turbine housing and separately from the insert element. Mutual influences of respective, thermally induced deformations of the guide and the turbine housing can thereby be kept low or avoided, which is particularly beneficial to the robustness and performance assurance of the turbine.

In order to keep mutual interference of the thermally induced deformations of the guide and the turbine housing particularly low, the guide can be fixed by means of at least one rigid fastener on the turbine housing. Preferably, the guide is at least predominantly spaced from the turbine housing.

The rigid fastening element can be a bolt, a screw or the like, by means of which the guide device is fixed in the axial direction and in the radial direction relative to the turbine housing. The rigid fastening element is partially accommodated in the turbine housing and partially in the guide on the one hand. Alternatively, the rigid fastening element can be partially accommodated in the guide device and partially in another housing element, in particular a bearing housing, of the exhaust gas turbocharger. In this case, the otherwise housing element is connected to the turbine housing, so that thereby the guide is fixed via the otherwise housing part relative to the turbine housing.

Preferably, a plurality of rigid fastening elements is provided to illustrate an advantageous attachment, which are advantageously arranged distributed in the circumferential direction of the guide at least substantially evenly.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or in the figures alone can be used not only in the respectively indicated combination but also in other combinations or in isolation, without the scope of To leave invention.

The drawing shows in the single figure fragmentary a schematic longitudinal sectional view of a turbine of an exhaust gas turbocharger, with a turbine housing which is formed in two parts and comprises two separately formed and interconnected housing parts.

The figure shows a turbine 10 an exhaust gas turbocharger of an example designed as a reciprocating internal combustion engine internal combustion engine of a motor vehicle. The turbine 10 includes a turbine housing 12 with a first housing part 14 and a second housing part 16 , The second housing part 16 closes in the axial direction of the first housing part 14 on and is with the first housing part 14 connected. For connecting the housing parts 14 . 16 For example, screws are provided, one screw of which 18 is indicated in the figure.

The exhaust gas turbocharger also includes a bearing housing 20 , which in the axial direction to the second housing part 16 of the turbine housing 12 connects and with the second housing part 16 connected is.

The bearing housing 20 serves to support a rotor of the exhaust gas turbocharger. The rotor comprises a shaft and a turbine wheel of the turbine 10 , which is rotatably connected to the shaft. The rotor also includes a compressor of a compressor of the exhaust gas turbocharger, which is rotatably connected to the shaft.

The turbine housing 12 has a receiving space, not shown in the figure, in which the turbine wheel at least partially about an axis of rotation relative to the turbine housing 12 is received rotatably.

The turbine housing 12 also has a flow channel 22 which is fluidically connected to at least one combustion chamber, in particular a cylinder, of the internal combustion engine. This allows exhaust gas from the combustion chamber in the flow channel 22 one and the flow channel 22 flow through.

The flow channel 22 is also referred to as a volute and is designed for example as a spiral channel. The flow channel 22 extends in the circumferential direction of the turbine wheel over the circumference at least substantially helically. About the flow channel 22 is this the flow channel 22 exhaust gas flowing through the receiving space and thus the turbine wheel, so that the exhaust gas can flow to the turbine wheel and thereby drive.

The turbine 10 further includes a separate from the turbine housing 12 and from the bearing housing 20 trained insert element 24 , which is at least substantially annular.

As the figure can be seen, is the flow channel 22 partly from the second housing part 16 and partly of the insert element 24 limited. The insert element 24 limits the flow channel 22 in the axial direction of the bearing housing 20 path.

For fastening the insert element 24 this is partially between the housing parts 14 . 16 arranged and clamped between them. This is a clamping element 26 provided, under whose mediation the insert element 24 on the first housing part 14 is supported in the axial direction. The clamping element 26 is for example a spring element, by means of which the insert element 24 Federkraftbeaufschlagt and thereby fixed.

The insert element 24 may be during operation of the turbine 10 in which hot exhaust gas the flow channel 22 flows through, at least substantially unhindered relative to the turbine housing 12 move thermally, without causing tension.

The turbine 10 also includes an adjustment 28 , which in a timely and cost-effective manner in the axial direction of the turbine 10 at least partially into the turbine housing from the side of a turbine outlet 12 can be inserted and mounted. The adjusting device 28 thus represents a cassette, which is particularly easy to assemble by the described insertion.

The adjusting device 28 is separate from the turbine housing 12 , from the insert element 24 and from the bearing housing 20 formed and includes a contour element 30 , by means of which a further flow channel in the turbine outlet, via which the exhaust gas is discharged from the turbine wheel, is at least partially limited in the radial direction.

The adjusting device 28 further comprises an adjusting element 32 , which is also referred to as axial slide. The adjusting element 32 is in the axial direction of the turbine 10 relative to the turbine housing 12 displaceable. By moving the axial slide relative to the turbine housing 12 can be a so-called effective flow area 34 the turbine 10 , via which the exhaust gas is supplied to the turbine wheel, can be set variably. In this case, the axial slide is displaceable in an adjustment range which is limited by a first end position and a second end position which belong to the adjustment range. In the first end position is the effective flow cross section 34 maximum released, leaving the turbine 10 can be flowed through by a particularly high exhaust gas mass flow. In the second end position, which is referred to as the closed position of the axial slide, is the effective flow cross-section 34 maximum narrowed. Between the end positions of the axial slide can be adjusted in several open positions, in which the effective flow cross-section 34 is fluidically narrowed relative to the first end position, but compared to the second end position (closed position) is fluidly released or enlarged.

The turbine 10 further includes a separate from the turbine housing 12 , from the insert element 24 , from the bearing housing 20 and of the adjusting device 28 separately designed guide grille 36 with a plurality of vanes 38 which is relative to the turbine housing 12 are immovable and which are arranged distributed in the circumferential direction of the turbine wheel over its circumference at least substantially uniformly.

The vanes 38 serve to divert or deflect the exhaust gas, so that the exhaust flow to the turbine wheel in flow-favorable angle of attack and thereby can drive efficiently. As the figure shows, the vanes protrude 38 only partially into the flow channel 22 into it.

In the axial direction of the turbine 10 joins the vanes 38 a front cover a cover 40 on which the vanes 38 projected in the radial direction to the turbine wheel and away from the turbine.

In the closed position is the axial slide (adjusting 32 ) at a the adjusting element 32 facing end face 42 the cover 40 at. The adjusting element 32 is designed as a solid slide and thus without a matrices, which the vanes 38 neither covered in the entire adjustment in the radial direction and does not receive in a recording. This leads to a high degree of robustness and thus functional reliability of the adjusting device 28 even at very high temperatures. In the closed position of the adjusting element 32 the at least substantially entire flows, the flow channel 22 flowing exhaust gas over the vanes 38 to the turbine wheel and is derived accordingly, so that the exhaust flow to the turbine wheel streamlined and can drive efficiently.

The turbine 10 has a adjustment room 44 on, from which the adjusting element 32 via a passage opening 46 out and into the flow channel 22 can enter. The contour element 30 has an optional anti-twist device 48 on, by means of which the adjusting element 32 against a relative rotation to the contour element 30 as well as to the turbine housing 12 is secured.

For fixing the guide grid 36 relative to the turbine housing 12 are three rigid Fasteners in the form of bolts 50 provided, with only one of the bolts 50 can be seen in the figure. Bolts 50 are in the circumferential direction of the guide grid 36 arranged at least substantially evenly distributed and partly on the one hand in each, the first receiving openings 52 of the bearing housing 20 and on the other hand partially in respective, second receiving openings 54 the Leitgitters 36 arranged in the radial direction of the turbine. In other words, the bolts extend 50 at least substantially in the radial direction of the turbine 10 , In the present case are the first receiving openings 52 formed as respective passage openings, so that the bolts 50 through the first receiving openings 52 through into the second receiving openings 54 can be inserted in the radial direction.

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 102009050951 A1 [0002]

Claims (10)

Turbine ( 10 ) for an exhaust gas turbocharger, with a turbine housing ( 12 ), which has at least one flow channel ( 22 ), which can be traversed by exhaust gas and via which the exhaust gas is a turbine wheel of the turbine ( 10 ), characterized in that the turbine housing ( 12 ) at least two in the axial direction adjoining and interconnected housing parts ( 14 . 16 ), between which at least in some areas an insert element ( 24 ), wherein the flow channel ( 22 ) partially of at least one of the housing parts ( 14 . 16 ) and partly of the insert element ( 24 ) is limited. Turbine ( 10 ) according to claim 1, characterized in that the insert element ( 24 ) between the housing parts ( 14 . 16 ) is clamped. Turbine ( 10 ) according to one of claims 1 or 2, characterized in that an adjusting device ( 28 ) with at least one relative to the housing parts ( 14 . 16 ) movable adjusting element ( 32 ) is provided, by means of which a flow cross-section ( 34 ), via which the exhaust gas can be supplied to the turbine wheel, is adjustable. Turbine ( 10 ) according to claim 3, characterized in that the adjusting element ( 32 ) in the axial direction relative to the housing parts ( 14 . 16 ) and the insert element ( 24 ) is displaceable. Turbine ( 10 ) according to one of the preceding claims, characterized in that at least one guiding device ( 36 ) with guide elements ( 38 ) is provided, by means of which the turbine to be supplied to the exhaust gas can be derived. Turbine ( 10 ) according to claim 5 and one of claims 3 or 4, characterized in that the adjusting element ( 32 ) in an adjustment range relative to the guide elements ( 38 ) and in the at least predominantly, in particular the entire, adjustment range without covering the guide elements ( 38 ). Turbine ( 10 ) according to claim 6 or according to claim 5 and one of claims 3 or 4, characterized in that the adjusting element ( 32 ) in its flow cross-section ( 34 ) maximum narrowing position at least indirectly on a the adjustment ( 32 ) facing end face ( 42 ) of the guide ( 36 ) is present. Turbine ( 10 ) according to one of claims 5 to 7, characterized in that in the axial direction of the guide elements ( 38 ) a cover element ( 40 ) of the guide ( 36 ) connecting the guiding elements ( 38 ) in the radial direction to the turbine wheel and / or projected away from the turbine Turbine ( 10 ) according to one of claims 5 to 8, characterized in that the guiding device ( 36 ) separately from the turbine housing ( 12 ) is trained. Turbine ( 10 ) according to claim 9, characterized in that the guiding device ( 36 ) by means of at least one rigid fastening element ( 50 ) on the turbine housing ( 12 ) is attached.

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