EP1860284A1 - Casings assembling - Google Patents

Abstract

The housing has a bearing housing (1), and a gas inflow housing (2) lying on the bearing housing and concentrically surrounding the bearing housing. Radial grooves (13) are inserted into the bearing housing, and a spring clip (5) is guided into the grooves, where the clip is connected with the gas inflow housing in a positive, force-fit or material-conclusive manner. The clip deforms the bearing housing and the gas inflow housing against each other in an axial direction.

Description

Technical area

The invention relates to the field of exhaust gas turbochargers. It relates to a turbine housing, an exhaust gas turbine with such a turbine housing and a turbocharger with such an exhaust gas turbine.

State of the art

Exhaust gas turbochargers are used to increase the performance of internal combustion engines. They include an exhaust gas turbine driven by the exhaust gases of the internal combustion engine and a compressor for compressing the fresh air supplied to the internal combustion engine. Turbine wheel and compressor wheel are usually arranged on a common shaft. In the lower power range of up to a few megawatts, turbochargers with radially impinged turbine wheel and internal bearing of the shaft are predominantly used.

In uncooled turbochargers, in which the gas-carrying ducts are not cooled, the exhaust gas temperature is higher at the turbine inlet, whereby the thermal efficiency of the engine and the output of the air compressor per exhaust gas output increases.

The uncooled outer turbine housing, the gas inlet housing, which has a temperature of, for example, 650 ° C during operation, is usually mounted directly on the bearing housing, for example, considerably cooler, for example at 150 ° C. In certain applications, the bearing housing, in contrast to the gas-carrying channels, cooled to said temperature.

For attachment of the turbine housing on the bearing housing tabs or so-called profile clamp or V-band connections are used in conventional exhaust gas turbines. To achieve the highest possible efficiency, is the Air gap between the turbine blades to keep the turbine housing as small as possible. However, this requires that this housing wall and the turbine wheel at any time, especially during operation under full load and with appropriate thermal load of all parts, are centered against each other. Since due to the high temperature difference between the bearing housing and the turbine housing, the centering seat of the turbine housing to the bearing housing sometimes radially expands, the turbine housing against the bearing housing and in particular the turbine shaft mounted therein desaxieren, ie the turbine housing is opposite to the shaft and the turbine wheel arranged thereon in radial direction is no longer centered. Such a desaxation, which can be additionally supported by external forces, leads to contact of the turbine blade tips with the housing wall of the turbine housing, to corresponding wear or defects and, associated therewith, to considerable losses in the efficiency of the exhaust gas turbine.

EP 0 118 051 shows how by means of a star-shaped, in the radial direction movable groove / comb connections a desaxation of the hotter component can be avoided.

This conventional, relatively cost-intensive approach, in which the manufacturing process includes milling operations as well as pure turning operations, allows only a limited number of different housing positions due to the discrete number of groove / comb connections. With 3, 6, or 12 evenly distributed cams or grooves position changes of the outer turbine housing relative to the bearing housing of 120 °, 60 ° or 30 ° can be achieved. Desirable, however, is an approach in which the position of the outer turbine housing relative to the bearing housing can be adjusted substantially continuously.

EP 1 460 237 shows a connection between the bearing housing and the gas inlet housing a turbine of an exhaust gas turbocharger, in which a centering ring is provided for centering the gas inlet housing with respect to the shaft mounted in the bearing housing, wherein the centering ring and either the bearing housing or the gas inlet housing grooves and either radially or axially rectified centering cams Include engagement in the grooves. Due to the radially or axially rectified Zentrierungsnocken with corresponding grooves at least one of the connections between the bearing housing and the Centering ring and the centering ring and the gas inlet housing not form-fitting, whereby any positioning of the gas inlet housing relative to the bearing housing is made possible. The preparation of the centering ring is relatively expensive and expensive. In operation, this compound due to the elastic and relatively small cross section of the centering a limited transverse stiffness on.

Brief description of the invention

The invention has for its object to improve the housing of an exhaust gas turbine such that the exhaust gas turbine by means of improved centering of the turbine housing with respect to the shaft mounted in the bearing housing has a higher efficiency, while the greatest possible flexibility with respect to the positioning of the outer turbine housing parts to the bearing housing.

According to the invention, this object is achieved with a turbine housing having the features of patent claim 1.

The turbine housing comprises a bearing housing and a gas inlet housing resting on the bearing housing and concentrically surrounding the bearing housing in the bearing area. For centering the gas inlet housing with respect to the bearing housing grooves are radially aligned in the bearing housing. In the radial grooves clamping brackets are guided, which with the gas inlet housing conclusive, i. positive, non-positive or material fit, are connected. The clamping brackets brace the bearing housing and the gas inlet housing in the axial direction against each other. To adjust the tangential positions of the two housing parts, the clamps are released, then rotated a housing part to the desired angle and finally fixed the clamp again. The two housing parts remain concentric with each other, even if the two flanges have high temperature differences and thus radial dislocations. The gas inlet housing is centered on the flanks of the clamping bracket star-shaped in the side walls of the radial grooves of the bearing housing.

Preferably, the clamping bracket in the mounted state, a bias, which ensures the necessary axial clamping force for axially fixing the two housing parts. To strengthen the clamping force can be an additional Clamping screw can be used. With this combination, the clamping bracket can also be used without bias, thus ensuring easier installation.

In one embodiment of the turbine housing according to the invention, the clamping yokes in the gas inlet housing are guided in the circumferential direction in an annular groove. Due to the circumferential annular groove any tangential positions of the two housing parts to each other are possible.

In one embodiment of the turbine housing according to the invention, the clamping yokes in the gas inlet housing in the annular groove are positively clamped in the axial direction.

In one embodiment of the turbine housing according to the invention, the clamping yokes in the gas inlet housing in the annular groove are clamped non-positively in the circumferential direction. By advantageously conically shaped bearing surfaces, the clamping bracket wedged in the installed state in the annular groove and a tangential displacement is hindered or suppressed.

In one embodiment of the turbine housing according to the invention, the clamping yokes engage behind a free end with a radial projection of the bearing housing.

In one embodiment of the turbine housing according to the invention, the free end of the tensioning bow comprises a shoulder which is fixed positively in an annular groove of the bearing housing in the radial direction.

In one embodiment of the turbine housing according to the invention, the free end of the clamping bracket comprises a shoulder which is rotatably mounted in an annular groove of the bearing housing about a tangentially oriented axis of rotation.

In one embodiment of the turbine housing according to the invention, the clamping brackets for axially clamping the bearing housing and the gas inlet housing comprise two free ends, and between the two free ends at least one spring area.

Brief description of the drawings

Fig. 1

einen entlang der Achse geführten Schnitt durch eine Abgasturbine mit einem erfindungsgemässen Turbinengehäuse,

Fig. 2

einen vergrössert dargestellten Ausschnitt einer ersten Ausführungsform des erfindungsgemässen Turbinengehäuses nach Fig. 1, während dem Einsetzen eines Spannbügels,

Fig. 3

einen vergrössert dargestellten Ausschnitt einer zweiten Ausführungsform des erfindungsgemässen Turbinengehäuses nach Fig. 1, mit eingesetztem Spannbügel, und

Fig. 4

eine isometrische Detaildarstellung der Abgasturbine nach Fig.1.

Exemplary embodiments of the turbine housing according to the invention are shown schematically and explained in greater detail below with reference to the figures. In all figures, the same elements are provided with the same reference numerals. Show it:

Fig. 1

a guided along the axis section through an exhaust gas turbine with a turbine housing according to the invention,

Fig. 2

1 shows an enlarged section of a first embodiment of the turbine housing according to the invention according to FIG. 1, during the insertion of a tensioning bow,

Fig. 3

an enlarged section of a second embodiment of the inventive turbine housing according to FIG. 1, with inserted clamping bracket, and

Fig. 4

an isometric detail of the exhaust gas turbine according to Fig.1.

Way to carry out the invention

The exhaust gas turbocharger mainly consists of an exhaust gas turbine shown schematically as a radial turbine in Fig. 1 and a compressor, not shown. The exhaust gas turbine mainly comprises a housing and a turbine wheel 3 arranged rotatably therein. The housing comprises a bearing housing 1 and a spiral gas inlet housing 2 arranged radially outside the bearing housing, with a housing wall 22 on the gas outlet side and a housing area designated below as housing flange 21, with which the gas inlet housing rests on the bearing housing. The turbine wheel 3 with the hub 31 and the blades 32 is arranged on a rotatably mounted shaft 7. Compressor side is arranged on the shaft also not shown compressor wheel.

The gas inlet housing goes downstream in an inflow channel for the exhaust gases connected to the exhaust gas turbocharger, also not shown on the internal combustion engine. In the inflow passage, a guide device 4 for flow diversion is arranged between the gas inlet housing 2 and the turbine wheel 3. This comprises guide vanes 42 fastened to wall elements 41, which vanes can be designed to be adjustable in special embodiments of the exhaust gas turbine.

The gas inlet housing 2 is clamped in the axial direction with clamping straps 5 with the bearing housing 1. The clamps in each case engage behind radial projections of the two housing parts and clamp them against each other by means of spring force or by means of other clamping means 6.

The material used for the tension bow is preferably a highly heat-resistant material (eg Nim80).

Based on the enlarged view in Fig. 2, the assembly and operation of the clamping bracket will now be explained.

When mounting the exhaust turbine, the turbine wheel with the shaft is first inserted into the bearing housing. Subsequently, the gas inlet housing is pushed in the axial direction on the bearing housing. Depending on the attachment concept for the guide device, a wall part 41 of the guide device can still be clamped between the bearing housing and the gas inlet housing. In this case, the guide device, also called nozzle ring, previously pushed onto the bearing housing or inserted into the gas inlet housing. The gas inlet housing is pushed on the one hand with a radial support 29 on a radial support 19 of the bearing housing, while on the other hand the gas inlet housing is in contact with an axial support 28 against an axial support 18.

The finished on the bearing housing 1 deferred gas inlet housing 2 is then secured according to the invention with clamps 5.

The clamps are S-shaped, i. they include two oppositely directed, free ends. The one, the gas inlet housing facing the free end is formed as a hook 51 which engages in a circumferential radial groove 23 of the housing flange 21. The other free end engages behind a radial projection 12 on the bearing housing. Between the two free ends, the clamping bracket has at least one spring part 53, which exerts a corresponding counterforce on a pulling force acting on the free ends.

During assembly, the clamping bracket 5 is pivoted radially from the outside into the annular groove 23 of the housing flange 21. The tip of the hook 51 engages behind the Ringnutumrandung 24. Subsequently, the clamping bracket is pivoted with the other free end radially inward. In this case, the support region 54 slides at the base of the hook 51 along a bearing surface 25 of the annular groove 23 until the hook wedged in the annular groove 23 between the annular groove border 24 and the support surface 25. The other free end is meanwhile pushed over the radial projection 12. This is done against a certain resistance, since the clamp is spread in the spring area and thereby subjected to a voltage. For axial securing of Gas inlet housing 2 with respect to the bearing housing, it should be sufficient that the free end engages behind the radial projection. The tensioned on axial train clamping bracket would wedged on the one hand on the side of the gas inlet housing in the radial groove 23 without excessively move on the opposite side along the radial projection.

So that it comes to the most optimal form-fitting connection between the clamping bracket and the gas inlet housing, the annular groove edge 24 advantageously has a bearing surface with an inclination of 20-60 degrees to the turbine axis. The tip of the hook 51 may also be provided with a chamfer, so that the hook wedged under axial Zugsbelastung between the axis-parallel support surface 25 and the inclined bearing surface of the Ringnutumrandung. This wedging also provides frictional engagement for securing the tension bow to the gas inlet housing in the circumferential direction.

According to the invention, however, the clamping brackets are concerned not only for the axial attachment of the gas inlet housing 2 on the bearing housing 1, but also for the centering of the gas inlet housing 2 with respect to the bearing housing 1 and the shaft 7 mounted therein with the turbine wheel 3. For this purpose, as shown in FIG. 4, a plurality of star-shaped radial grooves 13 are arranged in the bearing housing 1. The clamps are arranged in the radial grooves 13 of the bearing housing. The radial grooves have mutually parallel groove walls 14, along which the clamps are guided with their lateral edges 56. Advantageously, the clamping straps are only partially guided in the radial grooves, so that the frictional resistance is limited.

Moves the gas inlet housing radially outwardly during operation of the exhaust gas turbine, the two radial bearing surfaces 19 and 29 separate due to the greater heating of the gas inlet housing. The bearing surface 25 on the radially inner edge of the radial groove 23 presses on the support region 54 of the tension bow. The wedged in the radial groove clamping bracket is therefore raised radially outward. In order to prevent the clamping bracket is lifted radially outwardly from the radial grooves 13 and over the radial projection 12, the free end opposite the hook is fixed in a form-locking manner in an annular groove 11 in the radial direction. This annular groove is advantageously equipped with a circular segment-shaped cross-section, so that this leads to a likewise circular segment-shaped shoulder trained end of the clamping bracket in the annular groove can rotate. So now if the clamping ring is raised at the gas inlet housing end, the clamping ring rotates about an axis of rotation tangentially aligned with respect to the turbine shaft. The rotational movement allows the clamp to move in the radial groove 13. The gas inlet housing 2 is thus centered on the flanks 56 of the clamping bracket star-shaped in the side walls 14 of the radial grooves 13 of the bearing housing 1. In the inventive housing connection, the two housings, the bearing housing and the gas inlet housing, concentric with each other, even if the two housing high Temperature differences and thus have radial dislocations.

When mounting this clamping bracket this is pushed over the radial projection 12 until it engages with its shoulder 52 in the annular groove 11.

As already mentioned, the clamping bracket in the assembled state preferably has a bias which ensures the necessary axial clamping force of the two housing parts. Alternatively, or to reinforce the clamping force can, according to the embodiment of FIG. 3, as clamping means 6, a screw are used, which is used for the axial contraction of the clamping bracket. The screw is inserted into holes 55 provided in the clamp. So that the screw is not present on the bearing housing, a recess 15 is also provided in the region of the radial groove 13, as shown in FIG. 4 can be removed. With the clamping means 6, the clamping bracket can also be used without bias, which simplifies the assembly, since the clamping bracket can be pushed without resistance on the radial projection 12 on the bearing housing. For the combination with the clamping screw, the bearing housing 1 may be provided in the region of the radial groove 13 with recesses 15. This ensures a direct flow of force without restricting the spring portion 53 of the bracket.

Is the annular groove 23 circumferentially formed in the gas inlet housing, so that it extends along the entire circumference, any tangential positions of the gas inlet housing with respect to the bearing housing are possible. By the conical bearing surfaces in the interior of the radial groove 23, the clamping bracket 5 wedged in the installed state in the annular groove 23 and a tangential displacement is prevented by friction or frictional connection.

To adjust the tangential position of the gas inlet housing with respect to the bearing housing, consequently, the clamping bracket need to be solved. Subsequently, the gas inlet housing can be rotated by the desired angle and finally the clamps are fixed again.

LIST OF REFERENCE NUMBERS

1

bearing housing

11

ring groove

12

radial projection

13

radial groove

14

Radialnutwände

15

recess

18

axial support

19

radial bearing

2

Gas inlet casing

21

Gehäuseflsansch

22

gas outlet wall

23

ring groove

24

Ringnutumrandung

25

bearing surface

28

axial support

29

radial bearing

3

turbine

31

hub

32

blades

4

guide

41

wall elements

42

vanes

5

tensioning bow

51

hook

52

shoulder

53

spring range

54

support area

55

Drilling hole for clamping device

56

Flanks of the tension bracket

6

clamping means

Claims (10)

Turbine housing, comprising a bearing housing (1) and a gas inlet housing (2) lying on the bearing housing and concentrically surrounding the bearing housing in the bearing area,
characterized in that
for centering the gas inlet housing with respect to the bearing housing in the bearing housing (1) radially aligned grooves (13) are embedded and in the radial grooves (13) clamping bracket (5) are guided, which are connected to the gas inlet housing (2) and the bearing housing (1 ) and the gas inlet housing (2) in the axial direction against each brace. Turbine housing according to claim 1, characterized in that the clamping bracket (5) in an annular groove (23) of the gas inlet housing (2) are guided in the circumferential direction. Turbine housing according to one of claims 1 or 2, characterized in that the clamping bracket (5) in an annular groove (23) of the gas inlet housing (2) are positively clamped in the axial direction. Turbine housing according to claim 3, characterized in that the clamping bracket (5) in the annular groove (23) of the gas inlet housing (2) are clamped non-positively in the circumferential direction. Turbine housing according to one of claims 1 to 4, characterized in that the clamping bracket (5) engage behind with a free end a radial projection (12) of the bearing housing (1). Turbine housing according to claim 5, characterized in that the free end of the clamping bracket comprises a shoulder (52) which is fixed positively in an annular groove (11) of the bearing housing in the radial direction. Turbine housing according to one of claims 5 or 6, characterized in that the free end of the clamping bracket comprises a shoulder (52) which is rotatably mounted in an annular groove (11) of the bearing housing about a tangentially oriented axis of rotation. Turbine housing according to one of claims 1 to 7, characterized in that the clamping bracket for the axial clamping of the bearing housing and the Gas inlet housing two free ends, and between the two free ends at least one spring portion (53). Exhaust gas turbine comprising a turbine housing according to one of the preceding claims with a gas inlet housing (2) and a bearing housing (1), and a shaft (7) rotatably mounted in the bearing housing,
wherein the gas inlet housing is centered with the bearing housing with respect to the shaft and connectable at any angle. Turbocharger comprising an exhaust gas turbine according to claim 9.

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