EP1536103B1 - Turbo machine having inlet guide vanes and attachment arrangement therefor - Google Patents

Description

Field of the invention

The present invention relates to a turbomachine according to the preamble of claim 1.

Such turbomachines are conventionally designed in a variety of ways, for example as secondary air pumps or turbines, but especially as a turbocharger, which often have separate and attached housing parts for the turbine and their storage. Therefore, the term "housing assembly" in the context of the present invention should be understood to include either the turbine or the bearing housing or both.

Background of the invention

Guideways are subjected to the most diverse, including pulsating, stresses in turbomachines, be it by the forces of the flow medium itself, be it by temperature influences or by externally coming and impressed vibrations (for example, an internal combustion engine). In order not to let these influences come into effect, guide gratings have hitherto been clamped either on a wall of the housing itself or via a carrier ring, but in any case fixedly in the housing, usually in a turbine housing. Examples of this can be found in the EP-B1-0 226 444 , of the US-A-5,146,752 where the carrier or blade bearing ring is clamped by bolts.

One also knows the problem of the distortions within such a Leitgitters. In the case of a variable geometry baffle, this can lead to the blocking of the moving vanes, such as the one mentioned EP-B1-0 226 444 performs. Such distortions, which usually occur periodically, also lead to fatigue of the material. This is especially bad when dealing with turbines that are exposed to the changing influence of high temperatures, such as in turbochargers.

These problems are solved by the features of claim 1.

US-A-2,447,942 shows a distributor for a turbine in which the vane ring g is supported with axial and radial play.

DE-A-197 03 033 shows an exhaust gas turbine of a turbocharger in which a ring seal is provided between a blade bearing ring also mounted axially and radially with play and a housing part.

The conventional rigid attachment, although inherently providing a desired fixed spatial relationship of the parts to each other, is detrimental to the faulting problem. Because, for example, temperature-induced strains of the material, when tightened, inevitably lead to the aforementioned distortions. But these should be avoided.

For this purpose, as in the aforementioned patents, the carrier ring is fixed by means of a fastening device axially and / or radially movable on the housing assembly.

This is intriguing, and one would almost think that could not work. In an arrangement as defined in the characterizing part of claim 1, but is not so, but now the fastening device takes on the forces acting on the guide grid forces and allows a, albeit small, compensation, so that the previously dreaded malfunction (see the said EP-A-0 226 444 ) be avoided.

This has a particularly favorable effect if the guide grid has a variable geometry, wherein the carrier ring is designed as a blade bearing ring for supporting the shafts or axles of moving guide vanes. Because the previously so difficult to control phenomenon of clamping the vanes, according to the invention certainly avoided as well as distortions of the blade bearing ring, which may also be cause for malfunction.

In itself, for example, axial mobility can take place with adaptation to temperature conditions in the manner known from the mounting of laser mirrors of a laser resonator on rods which stretch under the influence of temperature and thus the mirror (here at least one of the rings, such as the blade bearing ring). Keep in the correct distance, so as to avoid jamming of the vanes. However, it is preferred if the fastening device has a radially extending, in particular radially outer, recess, preferably a groove, in particular an annular groove, in the carrier ring and a recess, preferably a groove, in particular an annular groove, in a radially opposite wall of the housing arrangement, wherein an insert part, for example a snap ring, piston ring or Segerring) is provided between this recess or depression while allowing the axial and / or radial mobility. The reason for this preferred embodiment is that yes temperature changes are not the only influences which act on a guide grid, but - as already mentioned - also flow forces, and that with such a configuration, a certain, but limited mobility is made possible under all these influences.

Brief description of the drawings

Fig. 1

einen teilweisen Axialschnitt durch das Lager- und das Turbinengehäuse eines Turboladers, von dem die

Fig. 2

das Detail X der Fig. 1 in größerem Maßstab veranschaulicht und die

Fig. 3

ein Schnitt nach der Linie III-III der Fig. 1 ist, wogegen die

Fig. 4

in einer der Fig. 1 ähnlichen Darstellung eine abgewandelte Ausführungsform darstellt.

Further details of the invention will become apparent with reference to the following description of schematically illustrated in the drawings embodiments. Show it:

Fig. 1

a partial axial section through the bearing and the turbine housing of a turbocharger, of which the

Fig. 2

the detail X the Fig. 1 illustrated on a larger scale and the

Fig. 3

a section along the line III-III of Fig. 1 is, while the

Fig. 4

in one of the Fig. 1 similar representation represents a modified embodiment.

Detailed description of the drawings

According to Fig. 1 a turbine housing 2 is connected to a flange 16 of a bearing housing, from which a cylindrical piece 40 projects into the turbine housing 2 and supports the shaft 35 of a turbine rotor 4. The turbine housing 2 comprises a supply channel 9 surrounding the turbine rotor 4 for a fluid driving the turbine rotor 4 (in the case of a turbocharger this is the exhaust gas of an internal combustion engine), a rotor space 23 and an axial connection 10 through which the fluid or the exhaust gas is emitted again becomes.

In order to supply fluid to the turbine rotor 4 in a controlled or controlled amount, a device is provided at the outlet of the feed channel 9 or in front of the rotor chamber 23, which device is known in the art as the "variable turbine nozzle guide grid". This guide grid substantially comprises a ring of movable guide vanes 7 concentrically surrounding the turbine rotor 4, which are mounted on adjusting shafts (or stub shafts) fixedly connected to them in a carrier ring 6 coaxially surrounding the turbine rotor 4, which is known in the art - in the case of turbochargers - Also known as "blade bearing ring".

The rotation or adjustment of the adjusting 8 can in itself, for example from the US-A-4,659,295 Known manner be done by an actuator 11 has a control housing 12 which controls the control movement of a attached to her, only dash-dotted lines plunger member whose movement via an actuating lever 13, an associated with this actuating shaft 14 and for example via an opening in a behind the vane ring 6 located adjusting ring 5 engaging eccentric 15 is converted into a slight rotational movement of this ring 5 around the axis R.

Due to the slight rotational movement of the adjusting ring 5, the guide vanes 7 are adjusted relative to the turbine rotor 4 with respect to their rotational position in a known manner so that they are adjustable from an approximately tangential extending an extreme position in an approximately radially veriaufende other extreme position. As a result, the exhaust gas of an internal combustion engine supplied via the supply channel 9 is supplied to the turbine rotor 4 more or less before it exits again at the axial connection piece 10 extending along the axis of rotation R.

All of these arrangements are known in principle. It was suggested in an earlier proposal of the Applicant to make the adjusting ring 5 via held in a cage ring 22 rolling elements 3 between a running surface 20 of the adjusting ring 5 and a shoulder 21 of the carrier or blade bearing ring 6 and to make it more smooth. To install the baffle with the blades 7 as a modular unit in the turbine housing 2, i. with its attachment to the turbine housing 2 or, for example, on the cylinder piece 40 of the bearing housing, to allow a pre-assembly, preferably a releasably connectable Monatgering 29 is provided which limits the bucket storage space 8 together with the blade bearing ring 6. The mounting ring 29 is expediently already connected in the pre-assembly via bolts 30 with the blade bearing ring 6, wherein the corresponding axial distance for the blade bearing chamber 8 is given by known per se spacers.

As Fig. 1 also shows, the mounting ring 29 is pushed onto an annular shoulder 17 of a wall 2 'of the turbine housing 2 and optionally bolted or even with slight play placed to - as will be explained, to allow an axial displacement. A plate spring or a heat shield 32 may engage an inner flange 6 'of the blade bearing ring 6 to hold the guide grid in the axial direction and to press against the wall 2'. The other radial end of the plate spring 32 is located on the cylinder piece 40 of the bearing housing. Also in the axial direction of the mounting ring 29 relative to the wall 2 'may have an easy game.

Thus, where appropriate, a plate spring 32 is provided to load the blade bearing ring 6 on the radially inwardly located projection 6 ', this ring 6 is according to the invention secured such that it is a slight mobility, in the radial and / or in the axial direction, possible , This should now be on hand of the detail X of the Fig. 1 reproducing on a larger scale Fig. 2 be discussed. This attachment is made in the illustrated embodiment on the radially outer side of the blade bearing ring 6 at a bifurcated wall 27 of the turbine housing 2 (as is preferred), but the attachment could also be done radially inside the bearing housing, for example on the cylinder piece 40.

Fig. 2 show that, relationships in detail. The blade bearing ring 6 has a blade bearing chamber 8 facing portion of smaller diameter (in Fig. 2 right), who with. a game g is able to pass under an annular projection 33. The radial clearance g serves to enable radial expansions of the blade bearing ring 6. A section of the blade bearing ring 6 facing away from the blade bearing chamber 8 (left in FIG Fig. 2 ) has a larger diameter and has, relative to the inner surface of the wall 27, an equal or different game g 'g', which serves the same purpose. Thus, once a radial mobility due to thermal expansion unhindered possible.

As a supplement to the plate spring 32 ( Fig. 1 ) or even without this a fastening for the blade bearing ring 6 is now provided, which on the one hand does not hinder the radial mobility, but on the other hand, the blade bearing ring against a shoulder formed by the projection 33 shoulder surface 24 down. Theoretically, the arrangement could also be reversed in that the shoulder surface 24 or the projection lies on the side facing away from the blade storage space 8 and the loading takes place in the direction away from the blade storage space 8, but this is less preferred.

For the purpose of such, a limited mobility permitting attachment a radially extending recess 25 is provided in the larger diameter portion of the blade bearing ring 6, which could be formed as a single recess in itself (it would then several such wells distributed over the circumference of the blade bearing ring), but is designed for manufacturing reasons, but also because of easier assembly as a groove and in particular as an annular groove. in the present particularly preferred embodiment, it is an annular groove 25 with a spring ring 26 inserted into it, the suspension may be caused for example by corrugations, but is preferably designed in the manner of a snap ring, piston ring or Segerrings and an open separation point 28 (FIG. Fig. 3 ), so that the ends of the ring 26 which open at this separation point 28 can be elastically compressed to reduce its diameter. In this case, the radial depth of the groove 25 is suitably dimensioned so that it in the compressed state of the ring 26 whose, at least approximately, total radial width (possibly minus the game g ') can accommodate.

The inserted into this groove 25 spring ring 26 projects - again with some play - in a groove 25 opposite groove 31, which causes the fork shape of the radially inwardly projecting wall 27 in cross section. It is understood that - if only, distributed over the circumference of the vane bearing ring 6 recesses each with an insert to be used (with the cross section of the ring 26) and this groove 31 could be formed by distributed individual recesses or recesses, but that a groove or an annular groove is preferable. In order to load the blade bearing ring 6 against the shoulder surface 24, it is advantageous for the groove 31 and / or the ring 26 to be one Fig. 2 apparent bevel 32 '(the groove 31) and a wedge surface 34 (of the ring 26).

Due to the mutual abutment of the wedge or inclined surfaces 32 ', 34 results in the radially outwardly urging spring force of the ring 26 an axial component through which the blade bearing ring 6 is pressed in the apparent manner against the shoulder surface 24. The fact that the ring 26 has within the groove 31 a radial clearance g "and an axial clearance g" ', allows in both directions a certain mobility, which can also serve to compensate for manufacturing tolerances. It is understood, however, that the said axial component would also arise if only one of the two parts 26 or 31 had an inclined surface 32 'or the wedge surface 34. In any case, it is possible that in thermal expansion or other tendencies to a fault of the blade bearing ring 6 has both the possibility of radial expansion and an axial movement, in the former case, this strain is absorbed by the game g ', in the second case by the axial play g "', wherein the wedge surface 34 of the ring 26 shifts along the inclined surface 32'.

If you look at the arrangement Fig. 2 considered, then the question arises, as in an engaging in two opposing grooves 25 and 31 ring 26 the Assembly can be done. Of course, it would be possible - precisely because of the existing axial clearance g ', to press the ring 26 into the groove 25 and then to push the blade bearing ring under the wall 27. It is cheaper, however, if you want to provide the ring 26 with at least one mounting approach to reduce the separation point 28 by means of a tool can. Such an assembly approach could be, for example, a protruding projection or an opening, but it is preferred if at least one of the mounting lugs, preferably both, as, in particular integrally formed, eyelets 37 (FIG. Fig. 3 ) is trained. These eyelets 37 are according to the illustration of Fig. 3 formed on the upper side of the ring 26 on both sides of the separation point 28, but could possibly also protrude laterally in the axial direction. In this case, they are preferably integrally formed by co-punching, although it would theoretically be possible to weld or solder them on (which may possibly impair the elasticity of the ring 26).

When mounting you press, for example, with a pair of pliers, the two eyelets 37 against each other, so that the distance between the separation point 28 is at least reduced or even closed. This reduces the diameter of the ring 26 and this penetrates into the interior of the groove 25 (FIG. Fig. 2 ) one. To have access to the eyelets 37, the in Fig. 2 left boundary wall of the groove 31 has an axial slot opening 36 for the access of a mounting tool, such as a pair of pliers, to the eyelets 37 on.

In case of Fig. 4 Although an inclined surface 32 'of the groove 31 is still present, but the ring 26' has no wedge surface, but is rounded at the radial outer side. While in the execution after Fig. 1 the vane ring 6 and the mounting ring 29 were connected by bolts together, this is in the execution after Fig. 4 no longer the case, but rather an integrally formed minimum spacer 38 is provided on the blade bearing ring, which is under the axial force component, which imprints him the spring ring 26, either against the Möntagering 30 'or directly against the wall 2' of the turbine housing 2 is supported. Should therefore expansions and deformations occur in the axial direction, which threaten to affect the free movement of the vanes 7, the spacer 38 lifts from the opposite surface (of the ring 30 'or the wall 2'), wherein the resilient ring 26 'through Sliding relative to the inclined surface 32 'allows such evasion.

It is understood that now that the spacer 38 is no longer used to enforce a fastening screw, this spacer very aerodynamic and thin, for example, with an aircraft wing similar flow profile in the direction of Supply channel 9 can be formed to the rotation axis R, so that only small flow losses for the turbine wheel 4 supplied fluid can be expected. It is also possible, the spacer 38 opposite surface of the mounting ring 30 'deepen something, so that any axial movement of the spacer 38 is guided. Conversely, the mounting ring 30 'with (dashed lines indicated) holes 39 are provided to store stub axle 41 of the vanes 7 therein. As a result, the storage of these blades 7 does not deteriorate even when caused by distortions or strains a (limited) axial movement of the blade bearing ring 6 relative to the mounting ring 30 '. Nevertheless, vane ring 6 can be pre-assembled with the blade ring of the blades 7 and the mounted thereon mounting ring 30 'inserted into the turbine housing 2, in which case a special game against the annular shoulder 17 is no longer essential.

An aspect of the embodiment according to the invention with the ring 26 bridging two opposing grooves 25, 31 has not yet been discussed, namely that it simultaneously gives an excellent seal. Because the ring 26 ( Fig. 2 ) with its own wedge surface 34 (as preferred, if necessary, with a more or less rounded edge, as in Fig. 4 ) rests positively on the inclined surface 32, it virtually closes this way for leaking gases hermetically, whereas the deep groove 25 forms with the penetrating part of the ring 26, a labyrinth seal.

In the context of the invention numerous variants are conceivable; For example, the invention can also be applied to guide vanes of constant geometry. Also it would be straight in the case of the Fig. 4 possible to dispense entirely on a sloping or wedge surface in the groove 31 and bring about the loading force by the aforementioned plate spring 32. Conversely, on the plate spring 32 in the presence of at least one of the inclined or wedge surfaces 32, 34th

LIST OF REFERENCE NUMBERS

2 turbine housing 3 rolling elements 4 turbine rotor 5 adjusting 6 Nozzle ring 7 vanes 8th Vane space 9 supply channel 10 Axialstutzen 11 actuator 12 control housing 13 actuating lever 14 actuating shaft 15 eccentric 16 Flange d. bearing housing 17 annular shoulder 20 Tread v. 5 21 Shoulder of 6 22 cage ring 23 rotor chamber 24 Shoulder area v. 33 25 Groove in 6 26 spring washer 27 bifurcated wall v. 2 28 open separation point v. 26 29 mounting ring 30 bolt 31 Groove v. 27 32 Belleville spring 32 ' Bevelled surface v. 31 33 33 annular projection v. 27 34 Wedge surface v. 26 35 wave 36 Slot opening v. 27 37 eyelets 38 Minimum spacing 39 Drilling v. 30'r 40 Cylinder piece d. bearing housing

Claims (7)

1. Turbomachine having a guide grate in a housing arrangement (2, 40) which accommodates a turbine (4) and which has a central outlet port (10), which guide grate has the following:

   a circle of guide blades (7) arranged around a central axis (R);

   a carrier ring (6) on which the circle of guide blades (7) is mounted around the central axis (R), which carrier ring (6) is inserted into the housing arrangement (2, 40);

   wherein

   the carrier ring (6) is fastened in an axially and/or radially movable manner to the housing arrangement (2, 40), and preloaded axially against the housing arrangement (27, 33), by means of a fastening device (26, 27, 31-34), characterized in that the fastening device (26, 27, 31-34) has a radially extending, in particular radially outer recess (25), formed as an annular groove, in the carrier ring (6) and a depression (31), formed as an annular groove, in a radially opposite wall (27) of the housing arrangement (2, 40), and in that an insert part (26) is provided between said recess (25) and depression (31) so as to permit the axial and/or radial mobility, wherein the insert part (26) is in the form of a resilient ring which is inserted into the annular grooves and which has a radially outer wedge surface (34), or a rounded portion, for abutment against a portion of the wall (27) within the groove (31) thereof, and the annular groove (31) has a wedge surface (32) for the abutment of the resilient ring (26).
2. Turbomachine according to Claim 1, characterized in that at least one of the following features is provided:

   a) it is embodied as a turbocharger;

   b) the guide grate has a variable geometry, wherein the carrier ring (6) is in the form of a blade bearing ring for the mounting of the shafts or axles (41) of movable guide blades (7), and preferably the guide blades (7) are arranged between it (6) and an opposite mounting ring (30; 30').
3. Turbomachine according to Claim 1 or 2, characterized in that the housing arrangement (2, 40) has a stop (24) and the carrier ring (6) is loaded in a force-fitting manner against said stop (24) by the fastening device (26, 27, 31-34), and in that, preferably, the loading of the fastening device (26, 27, 31-34) exhibits a force directed toward the guide grate.
4. Turbomachine according to one of Claims 1-3, characterized in that the resilient ring (26) has at least one assembly engagement means, in particular at least one eyelet (37), and in that the respective annular groove (31) has an axial slot opening (36) for the access of an assembly tool to the assembly engagement means (37).
5. Turbomachine according to one of Claims 1-4, characterized in that a spacing (g", g"') for permitting free movement is provided between the carrier ring (6) and the radially opposite wall (27) of the housing arrangement (2, 40) and/or between the insert part (26) and the inner wall of the recess (31) and/or depression (25).
6. Fastening ring for a turbomachine according to one of Claims 1-5, which ring (26) is formed from a resilient ring material which has a parting point (28), characterized in that, on both sides of the parting point (28), there is provided in each case at least one assembly engagement means (37) for the compression of the ring (26).
7. Fastening ring according to Claim 6, characterized in that at least one of the assembly engagement means, preferably both, are formed as in particular integrally formed eyelets (37).

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