Tube-type vortex reducer with retaining ring

A tube-type vortex reducer conducts cooling air in a compressor (1) of a gas turbine. Radial secondary air tubes (2) are arranged in a disk interspace (5) and attached to a compressor disk (3) with their radial outward end sections. The end sections of the secondary air tubes (2) are attached to a separate carrier ring (6), which is connected to a compressor disk (3).

This application claims priority to German Patent Application DE10310815.7 filed Mar. 12, 2003, the entirety of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

This invention relates to a tube-type vortex reducer. More particularly, the present invention relates to a vortex reducer for the conduction of cooling air in a compressor of a gas turbine, with radial secondary air tubes being arranged in a disk interspace and attached to a compressor disk with their radial outward end section.

In the state of the art, designs are known in which the secondary air tubes are fitted to corresponding locations on the disks by a pressing, riveting, screwing, snapping or forging process. These designs are disadvantageous in that adequate working space must be provided to enable the secondary air tubes to be installed with suitable tools. Therefore, the secondary air chamber, through which the secondary air enters the secondary air tubes, must be given a relatively large cross-section. This involves high manufacturing costs. Furthermore, the compressor disk may be damaged during the installation of the secondary air tubes. Since this disk is very expensive, risk of damage is a cost-relevant aspect of considerable importance.

BRIEF SUMMARY OF THE INVENTION

In a broad aspect, the present invention provides a tube-type vortex reducer of the type described at the beginning which, while being simply designed, is easily usable, dependable in operation, and can be produced cost-effectively.

It is a particular object of the present invention to provide solution to the above problems by the combination of the features described herein. Further advantageous embodiments of the present invention should be apparent from the description below.

The present invention accordingly provides for a secondary air tube, the end section of which is attached to a separate, segmented carrier ring which is separately connected to one of the compressor disks. The vortex reducer according to the present invention has a variety of merits.

As a first advantage, the inventive design enables the secondary air tubes to be attached by way of the carrier ring. Their installation immediately on the compressor disks is, therefore, not required. This precludes the compressor disks from being damaged.

A further, major advantage lies in the fact that the cross-section of the secondary air chamber can be kept small since no tools or similar equipment for the installation of the secondary air tubes need to be introduced into the secondary air chamber. Generally, this results in an increased stiffness of the compressor disks, which also provides for vibration reduction. The selected assembly method according to the present invention fully precludes disk damage, such as scratches, nicks or the like caused by the peening process, thus avoiding premature failure or rework.

It is particularly favorable if the secondary air tubes are attached to the carrier ring by way of a form fit. In a preferred form, this can be accomplished by means of a mounting shoe provided at the end section of the secondary air tubes which can be inserted into a slot of the carrier ring and secured by means of a locking element. This arrangement provides for a high degree of axial stability. It also facilitates assembly to a considerable extent.

In a preferred form, the carrier ring according to the present invention is given the shape of an angle section. This increases the inherent stability of the carrier ring and also enables the carrier ring to be provided with bolt holes for attaching the carrier ring to one of the compressor disks by means of axial bolts. The different positions of the slots and the bolt holes provide for an assembly-friendly, space-saving design, with each of the bolt holes being located centrally between adjacent slots. To facilitate assembly, the carrier ring, in accordance with the present invention, can be split into several, for example three, segments. The carrier can be inserted into the disk interspace without straining the segments.

For safe retention of the radial inward end section of the secondary air tube, it is particularly favorable to locate it on the compressor disk by means of a form fit. To accomplish this, no separate tooling is required which, again, would require appropriate working space or could lead to damage.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 17shows a partial sectional view of an inventive gas turbine. Reference numeral1shows a compressor comprising rotor blades11and stator vanes12. The rotor blades11are fixed to the compressor disks3or4, respectively. These form a disk interspace5in which several, radial secondary air tubes2are arranged. Reference numeral13indicates a combustion chamber, while reference numeral14designates a turbine in schematic representation. The arrows schematically indicate the route of the secondary air flow.

FIGS. 1 and 2show embodiments according to the state of the art. Obviously, the end sections of the secondary air tubes are riveted, as indicated by the reference numeral15. Reference numeral16designates an additional carrier disk which represents an additional volume element and is fitted in the disk interspace5.

FIG. 2shows a similar embodiment, with a riveted joint again being indicated by the reference numeral15. As becomes apparent, a very large secondary air chamber17must be provided to allow the riveting tool to be introduced.

FIG. 3shows a first embodiment according to the present invention. As can be seen, the free end of the secondary air tube is located on an angle-section carrier ring6. The secondary air chamber17can here be very small since no pressing tool needs to be introduced into it. The carrier ring6is attached to the compressor disk3by means of bolts18. The bolt18also holds a mounting flange19of the further compressor disk4. Thanks to the present invention, the carrier ring6can be dimensioned and designed such that a very favorable design of the mounting flange19can be achieved, resulting in an enlarged, improved radius20of said mounting flange19. Further, it is possible to minimize a chamber21at the radially outward end of the compressor disk3.

FIG. 4shows an axial partial view illustrating that the bolts18and the secondary air tubes2are offset relative to each other in alternation on the circumference.

FIG. 5shows an enlarged partial sectional view along line V—V ofFIG. 4, showing again in detail the carrier ring6and the bolts18as well as further locking elements and the nuts required.

FIG. 6shows a sectional view along line VII—VII ofFIG. 4with the secondary air tubes in the installed state. In particular, a mounting shoe7, which is detailed hereinafter, is shown on the end section of each secondary air tube2. Furthermore, a locking element9for the retention of the mounting shoe7is shown, this locking element9also being explained hereinafter.

FIG. 7is an axial view of the carrier ring6according to the present invention. As can be seen, individual mounting pads22with bolt holes10for the bolts18are provided.

As becomes apparent fromFIG. 7, the carrier ring6may include individual segments a, b and c to facilitate installation. Reference numeral23indicates the splits, these being located and arranged essentially radially (upper split inFIG. 7) as well as diagonally to the upper split. The large arrows24indicate the installation direction of the segments a, b and c.

FIG. 8is a perspective representation of the carrier ring6according to the present invention. The figure clearly shows that a slot8is provided between adjacent mounting pads22into which the mounting shoe7of the secondary air tube2can be inserted. Reference numeral25designates a registering skew, or a chamfered, skewed area of the locking element9, which enables the mounting shoe7to be accurately fitted. See also,FIGS. 9,10,12and13. The chamfered area of the locking element9faces radially outwardly and is configured to engage a corresponding radially inwardly chamfered area of the mounting shoe7of the secondary air tube2. This locking engagement secures the secondary air tube2in place and prevents the secondary air tube2from moving radially inwardly. The radially outwardly and inwardly facing portions can have alternative configurations other than chamfered.

FIGS. 10 and 11show assembly steps, illustrating the manner in which the individual mounting shoes7of the secondary air tubes2are inserted into the slots8.FIG. 11shows the finally assembled, inserted state. Subsequently, as shown inFIG. 12, the locking element9interacts with the mounting shoe7to clamp the secondary air tube2in place.

FIGS. 14 to 16again show various assembly states in different perspective.FIG. 14shows a state in which the carrier ring6is fitted between the two compressor disks3and4.FIG. 15shows the pre-assembly of the secondary air tubes2(analogically toFIG. 10).FIG. 16is a representation of the finally assembled state, analogically toFIG. 13.

As becomes apparent, in particular, each of the radially inward end sections of the secondary air tubes2is provided with a flange26(seeFIG. 11) which is insertable into a profiled, essentially circular recess27(seeFIG. 16) of the compressor disk4. This arrangement enables the free end sections of the secondary air tubes2to be retained effectively.

LIST OF REFERENCE NUMERALS