EP1398463B1 - Variable geometry guide vanes and turbocharger with these vanes - Google Patents

Description

Field of the invention

The present invention relates to a variable geometry baffle, in particular for a turbine housing with a central outlet, with a ring of vanes arranged around a central axis, each of which is pivotable about a pivot axis, a vane ring for supporting the vanes around the central one Axle and an adjusting ring which is pivotable relative to the blade bearing ring about the central axis and is connected to the blades for adjusting their angular position in each case about their pivot axes. Connections of this latter type have come to be known in a variety of ways, and may be formed by beams around the central axis of levers attached to vanes for the vanes, intermeshing tooth segments, or slot cams guiding lugs on the vanes. The present invention is not limited to any of these compounds.

Furthermore, the present invention also relates to a turbocharger with a guide grid according to the invention as well as with at least one turbine housing and a releasably attachable to this bearing housing.

Background of the invention

Guiding gratings of this type have become known from numerous publications, such as US-A-4,179,247 or US-A-5,146,752. Especially the latter shows how cumbersome to assemble the individual parts of the guide grid on the housing, as different parts must be plugged into each other, fitted and connected together, especially when installed in a turbocharger - or at least in a turbine unit. US-A-4,679,984 shows a baffle according to the preamble of claim 1.

Summary of the invention

The invention is based on the object to reduce the installation costs by a simple and compact design and to be able to mount a guide grid of the type mentioned easily and quickly.

This object is achieved with a guide grid according to claim 1. The object is achieved according to the invention in two stages in that the blade bearing ring opposite a central opening having disc with such an axial distance, based on the central axis, is arranged, that between it and the blade bearing ring, the ring of vanes, and that at the central opening at least one driver engages, which is attached to a retractable into the central outlet of the turbine housing sleeve, so that the sleeve for axial fixing of the guide grid in a turbine housing together with the guide grid in the central outlet can be inserted and fastened.

First, therefore, according to the invention, the assembly of the actual, known guide grid does not have to take place directly on a wall of the turbine housing, as was the case in the prior art mentioned above, but via a disk having a central opening. This makes it possible, for example, vorzumontieren the guide grid as a module (or "cassette"), which of course can be done easier and faster because of the smaller dimensions (in comparison with an installation directly into the turbine housing).

The assembly can be done by frictional retention of the sleeve in the central opening. But once you have provided the disc, then the module thus created (the "cassette") in a preferred manner in the turbine housing can be secured by providing the sleeve with at least one driver. This at least one driver is preferably formed by a radially extending and the disc engaging behind the flange.

However, the invention also relates to a turbocharger having such a guide grid, which has at least one turbine housing and a releasably attachable to this bearing housing. This turbocharger is inventively characterized in that on a bearing housing facing the opening of the outlet nozzle surrounding wall of the turbine housing at least one connector for radially fixing the guide grid is provided, whereas the axial fixing is carried out by a sleeve in the outlet holding fixture. In this way, an exact attachment in the shortest possible time and with minimal effort can be achieved.

Brief description of the drawing

Fig. 1

einen Axialschnitt aus dem Bereich des Überganges zwischen Turbinengehäuse und Lagergehäuse eines Turboladers, wo das erfindungsgemäße Leitgitter untergebracht ist; und

Fig. 2

eine teilweise perspektivische Ansicht des Leitgitters, welche etwa das Detail II der Fig. 1 in größerem Maßstab veranschaulicht.

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

Fig. 1

an axial section from the region of the transition between the turbine housing and the bearing housing of a turbocharger, where the guide grid according to the invention is housed; and

Fig. 2

a partial perspective view of the Leitgitters, which illustrates about the detail II of FIG. 1 on a larger scale.

Detailed description of the drawing

In the drawing, a part of a turbine housing 2 of a turbocharger 1 is shown, which typically has a spiral about a central axis R winding supply channel 9 for a fluid - in the case of a turbocharger of the exhaust gas of an internal combustion engine - has. This fluid is then supplied in the radial direction through a, known per se, arranged around the central axis R ring of vanes 7 a located on the axis R, not shown turbine rotor, which sits at the end of a (also not shown) shaft, the in a bearing housing 40, in bearings 41 and 41 'formed therein. In the case of a turbocharger, this shaft extends through this bearing housing 40 through to a compressor housing attached to the other end, the compressor rotor of the shaft - and thus of the turbine housing 2 supplied exhaust gases is driven in a known manner.

It has already been pointed to the guide vanes 7 per se known training, which are adjustable and thereby either a more radially inclined to the central axis R or extend approximately tangentially thereto. Fig. 2 illustrates these relationships,
wherein a rolling bearing with rolling elements 3 in the form of rollers between an adjusting ring 5 and a blade bearing ring 6, in which the pivot axes of the vanes 7 forming adjusting shafts 8 are mounted. The rotation or adjustment of the adjusting shafts 8 and the adjusting ring 5 which actuates them can be effected in a manner known per se and, for example, in the aforementioned US Pat. No. 4,659,295. In any case, causes the known control that the adjusting 5 rotates relative to the stationary blade bearing ring, resulting in a corresponding pivoting of the shafts 8.

Because in grooves or recesses 17 of the adjusting ring 5, the free ends of the levers or heads 18 are mounted by adjusting levers 19 which are fixed to the adjusting shafts 8. Instead of radially extending through recesses 17 but grooves can be provided on the radially inner side of the adjusting ring 5 in a conventional manner, in which the heads 18 are mounted so that then these heads 18 a certain Secure pre-centering. It is clear that this is just one possible embodiment, and it has already been noted at the outset that the adjustment could also be made via slot cams or intermeshing gears and could be transmitted.

As a result, the exhaust gas of an internal combustion engine supplied via the supply channel 9 is more or less supplied to the turbine rotor (not shown) located in the interior of the guide vane ring, before it exits again at the axial connection piece 10 extending along the central axis of rotation R. This outlet 10 is here decoupled by a decoupling space 42 of a follow it 43, but if desired, it can also be connected directly to an exhaust system.

The adjusting ring 5 has a radially inwardly directed running surface 20, on which the rollers 3 can run off. However, this is preferably provided only for tolerance compensation, because in practice it is preferred if the rollers 3 in substantially all operating conditions both with respect to this tread 20 and an opposite outer, forming a shoulder tread 21 on the blade bearing ring 6 have a certain play.

As FIG. 2 illustrates, only a relatively small number of rollers 3 are required if a cage or retaining ring 22 is assigned to them. Although the rollers 3 could also run in recesses of this retaining ring 22, the rollers 3 advantageously have axial extensions 24 of smaller diameter, which engage in holes 25 of the retaining ring 22 so that this one hand ensures their distance in the circumferential direction and on the other hand, the rollers and axially fixed on their track opposite the treads 20 and 21 holds.

A sealing ring 27 is inserted into a sealing groove 28 of the blade bearing ring 6. As a comparison with FIG. 1 shows, the blade bearing ring 6 lies in the region of a housing wall section 2a. Now various sealing arrangements are conceivable: Either the sealing ring 27 is formed as a flexible sealing lip, which lays against the wall 2a. This is not a problem in itself, because these two parts do not move relative to each other during operation. But it can also (possibly additionally) the (or a) sealing ring 27 protrude into a groove of the wall 2a and form a kind of labyrinth seal, and combinations of both possibilities are also possible, as can be found in the field of seals known solutions application. In any case, contaminants from the area of the feed channel 9 are kept away from the rolling bearing 3, 20, 21 with this seal.

In a spaced by the central axis R on the blade bearing ring 6 spacer sleeves 31 defined distance a blade 7 protective mounting ring or a disc 29 is provided which is mounted on the rotor housing 2 approximately in the region of the apparent from Fig. 1 housing flange 2b. The fastening ring 29 is indicated by dashed lines, e.g. fastened by the sleeves 31 bolt 30 'attached to the blade bearing ring 6, wherein in a known manner, the spacers 31 provide for a slightly greater distance than the width of the blades 7 corresponds, so as not to hinder them in their movement in all temperature ranges. In this way, therefore, the visible from Fig. 2 Leitgitter can be completely pre-assembled to be inserted into the turbine housing 2.

In order to use the module thus created quickly and accurately in the turbine housing 2, it is connected to a insertable into the central Axialstutzen 10 sleeve 45 with a central opening 53, which needs to be used in principle only in the outlet 10. For this purpose, the sleeve 45 has at least one driver 46, which carries the disc 29 - and thus the whole Leitgitter module - when inserted into the outlet port 10 and thus determines the axial position of the module. If "at least one" driver 46 is mentioned here, it should be understood that it would be possible to provide a plurality of radially protruding projections or projections, in particular at uniform angular intervals, over the circumference of the sleeve 45. It is preferred, however, if - as shown in Fig. 2 - the driver as radially extending from the sleeve 45 extending, the disc 29 engages behind the flange 46 is formed.

It can be seen particularly from Fig. 1 that it is advantageous if the disc 29 at the central opening at least one recess 47, in which the at least one driver 46 engages, so that it is preferably flush with the surface of the disc 29. In the above-described case of a plurality of radial projections distributed over the circumference, a plurality of recesses distributed over the circumference could also be provided. This would be done at the same time a precise definition of the Leitgitter module in the direction of rotation around the central axis R. However, such individual and precise recesses are more difficult to produce, which is why it is preferred if the recess 47 is formed as a groove extending in the circumferential direction of the sleeve 45 (see FIG. Fig. 1 shows clearly that at the same axial depth of the groove 47 and the flange 46 of the latter with the surface of the disc 29 is flush, so that the Flow conditions in the region of the guide vanes 7 are not impaired. Of course, the use of an annular groove 47 would also be possible if the sleeve possessed only individual, arranged at angular intervals projections as a driver, but this then leads to a disturbance of the flowing to the vanes 7 exhaust stream.

For fixing in the circumferential direction, at least one bore 48 (FIG. 2) and / or 48 '(FIG. 1) is preferably provided in the disc 29, which accommodates a pin 49 seated in the turbine housing 2, specifically in the wall 2b. It has already been pointed out above that the fixing in the circumferential direction could also take place through the recesses (at least one). According to another alternative, the arrangement could be reversed, so that the disc 29, for example a molded, carries pin which is inserted into a hole of the wall 2b. Furthermore, the definition in the circumferential direction could also be done with the help of bolts, but this is not preferred because of the additional assembly costs.

In the illustrated embodiment, the turbine housing 2 is machined so that the insertion of the sleeve 45 by screwing by means of a thread 50 takes place. Therefore, an internal thread must be cut into the axial neck 10, into which a corresponding external thread of the sleeve 45 can be screwed. In itself, the axial fixing is secured when the disc 29 abuts the wall 2b. However, vibrations during operation may cause the thread to loosen. Therefore, for securing the sleeve 45 can be welded or plastically deformed.

Moreover, it is expedient to provide a heat shield 32 'between the bearing housing 40 and the space enclosed by the guide grid. This heat shield is in the present embodiment on the one hand on a surface of the guide rail - expedient on the blade bearing ring 6. For this purpose, the blade bearing ring 6 at least one radially inwardly (with respect to the central axis R) directed projection 54 have. Again, it is (as in the recesses 47 discussed above) again possible to provide several, distributed over the inner circumference of the blade bearing ring 6 projections, but you will, even for manufacturing reasons, a radially inwardly projecting flange as a projection 54 arrange. On the other hand, the heat shield is located on a wall of the bearing housing 40. Of course, other arrangements are possible.

Again, this is just one of many possible embodiments. Because it would also be possible to use other known means of securing a thread, such as a lock nut (in sleeve form), for example, from the left in Fig. 1 side. Another possibility would be to use at least one clamping screw in the Axialstutzen 10, which protrudes as a projection against the interior of the nozzle 10 and the sleeve 45 clamps. It would also be possible to provide other projections (as indicated at 52), which engage in at least one recess 51 (continuous, as shown in Fig. 1, or located only on the outside of the sleeve) and thus determine the axial position exactly. In general this will be difficult with a rigid sleeve 45, but it would be possible to use the left end of sleeve 45 in Fig. 1 as, e.g. in axial grooves of the axial neck 10 engaging, form spring tongues, which snap into corresponding locking projections. Of course, this arrangement can be reversed again by the sleeve 45 has at least one radially outwardly projecting projection which engages in a recess of the axial neck 10. In principle, however, the recesses 51 will expediently serve at least for applying a corresponding tool.

A further possibility in the context of the invention would be to not determine the end position of the guide grid module by the surface of the wall 2b facing it, but to make it adjustable by means of an adjusting arrangement. For example, from the left side (with reference to FIG. 1), at least one, preferably several, adjusting screws determine with their ends on the right side the plane in which the disc 29 is to lie.

LIST OF REFERENCE NUMBERS

1

turbocharger

3

Rolling elements (rollers)

5

adjusting

7

vanes

9

supply channel

17

recess

19

adjusting

21

Tread v. 6
23

25

Holes of 22

27

sealing ring

29

Washer (fixing ring)

31

spacer

40

bearing housing

42

decoupling room

44

spacer

46

Driver, flange

48

drilling

50

thread

52

head Start

54

Advantage of 6

2

Turbine or rotor housing

4

bearing housing

6

Nozzle ring

8th

Adjusting shaft, swivel axis

10

Axial nozzle, outlet nozzle

18

Head or lever end v. 19

20

Tread v. 5

22

Cage or retaining ring

24

axial extension
26

28

seal groove
30

32 '

heat shield

41.41 '

Warehouse in 40

43

Continued from 10

45

shell

47

recess

49

pen

51

recess

53

central opening of 45

Claims (10)

1. Guiding grid of variable geometry, particularly for a turbine housing (2) having a central discharge pipe (10), which comprises:

   a ring of guiding vanes (7), arranged around a central axis (R), which are each pivotal about a respective pivoting axis (8);

   a vane supporting ring (6) for supporting said vanes (7) around said central axis (R);

   a unison ring (5) which is pivotal relative to said vane supporting ring (6) about said central axis (R) and is connected to said vanes (7) to adjust their angular position about their respective pivoting axes (8);

   wherein a disk (29) having a central opening (53) is arranged opposite said vane supporting ring (6) and with such an axial distance in relation to the central axis (R), that said ring of guiding vanes (7) is between it and said vane supporting ring (6), characterised in that a sleeve (45) pertaining to said guiding grid may be inserted into said central opening (53) or the central discharge pipe (10) of the turbine housing (2), so that said sleeve (45) together with said guiding grid, for fixing said guiding grid in axial direction in a turbine housing, may be inserted into its central discharge pipe (10).
2. Guiding grid according to claim 1, characterised in that at said central opening (53) at least one dog (46) engages it and is provided on said sleeve (45) which may be inserted into said central opening (53) of the turbine housing (2).
3. Guiding grid according to claim 2, characterised in that said at least one dog (46) is formed by a radially extending flange which grasps behind said disk (29).
4. Guiding grid according to any one of the preceding claims, characterised in that said disk (29) comprises at least one recess (47) at the central opening (53) into which said at least one dog (46) is engaging.
5. Guiding grid according to claim 4, characterised in that said at least one dog (46) is flush with the surface of said disk (29).
6. Guiding grid according to claim 4 or 5, characterised in that said recess (47) extends in an annular shape around said central opening (53), and that said dog (46) is preferably formed as a radially projecting flange.
7. Guiding grid according to any one of the preceding claims, characterised in that at least one fastening means for fastening said sleeve (29) to said discharge pipe (10) of said turbine housing (2) is provided at the external side of said sleeve (29), e.g. a thread.
8. A turbocharger comprising a guiding grid according to any one of the preceding claims, and comprising at least one turbine housing (2) and a bearing housing releasably attached to it, characterised in that at least one plug connection (48', 49) for fixing the guiding grid in peripheral direction is provided on a wall (2b) of the turbine housing (2) which faces the bearing housing and surrounds the opening of the discharge pipe (10), whereas axial fixation is effected by means (50-52), which hold the sleeve (29) in the discharge pipe (10).
9. Turbocharger according to claim 8, characterised in that said disk (29) comprises at least one hole (48') for the penetration of at least one plug, pin (49) or the like for fixing the guiding grid in peripheral direction.
10. Turbocharger according to claim 8 or 9, characterised in that said means (32', 50-52), which hold said sleeve (29) in axial direction comprise at least one protrusion (52) on said discharge pipe (10) which engages said sleeve (29), particularly a recess (51) thereof.

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