Gas turbine with axially moveable outer sealing ring with respect to housing against a direction of flow in an assembled state

Abstract

A gas turbine includes a housing and an outer sealing ring. In an assembled state of the housing and the outer sealing ring, a first planar structure of the outer sealing ring is axially moveable with respect to a second planar structure of the housing against a direction of flow through the gas turbine.

Claims

1. A gas turbine, comprising: a housing; an outer sealing ring; and a C-ring, wherein the C-ring is a separate component from the housing, wherein the outer sealing ring is connected to the housing by the C-ring in an assembled state of the housing and the outer sealing ring, and wherein a first planar structure of the outer sealing ring is axially moveable with respect to a second planar structure of the housing against a direction of flow through the gas turbine when the C-ring is released from the outer sealing ring and the housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows one part of a gas turbine with a tool according to one embodiment of the present invention;

(2) FIGS. 2A-2C show steps of a method for disassembly of a rotor of a gas turbine according to one embodiment of the present invention;

(3) FIG. 3 shows one part of a gas turbine according to another embodiment of the present invention;

(4) FIG. 4 shows an enlarged detail of the gas turbine from FIG. 3; and

(5) FIG. 5 shows a section along line V-V in FIG. 4.

DETAILED DESCRIPTION OF THE DRAWINGS

(6) FIG. 1 shows a low-pressure gas turbine having a housing 3 and a channel 5, which diverges in the direction of flow (from left to right in FIG. 1), in that its diameter increases essentially monotonically in the direction of flow.

(7) In the channel, a front rotor 19 in the direction of flow as well as several other rear rotors 21, 23 and 25 are arranged one after the other in the direction of flow.

(8) Guide baffles 11, 13, 15 and 17 are arranged between and/or in front of the rotors and are attached to the housing.

(9) The housing is detachably connected to a connecting flange 9 of a high-pressure turbine upstream from the low-pressure turbine 1 on its front end face (upper left in FIG. 1) and is connected to an outlet housing 7 on its rear end face (at the right in FIG. 1).

(10) An outer sealing ring 27, 29, 31 and/or 33 is arranged between each rotor and the housing.

(11) The rotor 19 to be disassembled has a plurality of rotor blades distributed in the circumferential direction, one of which is shown in part in FIG. 1, and a rotor disk (not shown) to which the rotor blades are attached.

(12) FIGS. 2A-C show steps in a method for disassembly of a rotor of a gas turbine of an aircraft engine according to one embodiment of the present invention on the basis of an enlarged partial diagram, corresponding essentially to FIG. 1, which is explained above, so that corresponding elements are labeled with identical reference numerals, and reference is made otherwise to the remaining description and only the differences are discussed.

(13) The rotor blades have outer casings on the outside radially, together forming an outer ring. The outside diameter of this outer ring increases in the direction of flow. The outer ring has two radial flanges and/or sealing tips 19a spaced a distance apart axially (see FIG. 2A), which extend radially outward, the outside diameter of a front radial flange (at the left in FIG. 2A) being smaller than the outside diameter of a rear radial flange (at the right in FIG. 2A).

(14) The outer sealing ring 27, which is arranged between the rotor 19 and the housing 3, is detachably attached to the channel and/or housing. To do so, a rear axial flange (at the right in FIG. 2A) of the outer sealing ring is suspended between the housing and a following guide baffle 13, and a front axial flange (at the left in FIG. 2A) of the outer sealing ring is attached to the housing by a C ring 45.

(15) The outer sealing ring is attached to the housing against the direction of flow in a friction-locking and detachable manner without any form-fitting connection. It can be seen here, in particular on the basis of the sequence of figures described below, i.e., FIG. 2A FIG. 2B, that the outer sealing ring is displaceable axially against the direction of flow (toward the left in FIG. 2A) after releasing the C ring, without thereby being hindered due to a stop on the friction contact area between the outer sealing ring and the housing.

(16) The inside circumferential surface of the housing 3 for the friction-locking connection to the outer circumferential surface of the outer sealing ring 27, which is on the opposite end radially, has a plurality of radial protrusions 3.1 (see FIG. 2B), which extend radially inward and engage in axial grooves in a rear end face (at the right in FIG. 2) of the outer sealing ring in the direction of flow in order to affix this to the housing in the circumferential direction as well as in a form-fitting manner in the direction of flow.

(17) The outer sealing ring has an abradable coating 59, formed as a honeycomb seal on the inside radially, i.e., facing the rotor.

(18) The inside diameter of the outer sealing ring increases monotonically in multiple steps in the direction of flow, where one shoulder of the assembled outer sealing ring is opposite a radial flange (at the left in FIG. 2A) of the outer ring of the rotor to be disassembled, while another shoulder of the assembled outer sealing ring is opposite another radial flange (at the right in FIG. 2A) of the outer ring.

(19) A minimum and most forward inside diameter d.sub.27 of the outer sealing ring 27 is smaller than the maximum outside diameter D.sub.19 of the rotor 19, in particular smaller than the outside diameter of its most rear radial flange 19a.

(20) For disassembly of the most forward rotor 19 out of the housing 3 toward the front and against the direction of flow, the connecting flange 9 (see FIG. 1), which is connected to the housing 3 and whose inside diameter (at the right in FIG. 1) facing the rotor is smaller than the maximum outside diameter D.sub.27 of the outer sealing ring (see FIG. 2A), is released from the housing 3.

(21) Then the connection of the outer sealing ring 27 to the housing 3 in the form of the C ring 45 is released, as indicated by an arrow in FIG. 2B.

(22) In advance, at the same time or subsequently, as also indicated by an arrow in FIG. 2B, the rotor 19 is displaced axially in the direction of flow to make space available for a radial shifting of the outer sealing ring parts toward the inside radially. In one modification that is not shown here, this step may also be omitted.

(23) The maximum outside diameter D.sub.27 of the outer sealing ring is larger than the minimum (inside) diameter d.sub.5 of the section of the channel lying in front in the direction of shifting (from right to left), so the outer sealing ring cannot be shifted completely out of the channel axially against the direction of flow. Therefore, for disassembly of the outer sealing ring 27, first it is displaced axially against the direction of flow and then it is divided into two or more parts, which are then shifted radially inward and/or toward an axis of rotation of the gas turbine, and in this way it also passes by the smaller inside diameter of the channel, as indicated by arrows in FIG. 2C. This radial shift toward the inside is also superimposed on an additional axial shift of the outer sealing ring and/or its parts against the direction of flow, as also indicated by these arrows.

(24) Next, the rotor 19 itself is displaced axially against the direction of flow toward the front out of the housing 3 and thus is disassembled directly without disassembly of the rear rotors 21, 23, and 25. The inspection and/or maintenance, in particular replacement of this rotor, can be simplified in this way.

(25) These additional rotors 21, 23, and 25 of the gas turbine 1 are secured by a detachable tool that is supported in turn on the housing 3 of the gas turbine, as indicated with the dotted line in FIG. 1, before the axial displacement of the rotor 19 that is to be disassembled against the direction of flow.

(26) The tool has a radial flange 101 for attachment to the housing 3 and an axial web 102, as well as fasteners 103, 104-106 for form-fitting and/or friction-locking attachment to the housing 3 and the additional rotors 21, 23, and 25. The fasteners may in particular have one or more recesses and/or protrusions for form-fitting attachment and/or have one or more tension devices, in particular screws, for friction-locking attachment (not shown).

(27) Initial assembly or reassembly of the front rotor 19 in the direction of flow into the housing 3 from the front takes place essentially in the reverse order from the disassembly described above, so that reference is made to this in addition.

(28) Accordingly, first the rotor 19 to be assembled and then the outer sealing ring 27 are displaced axially into the housing 3 in the direction of flow. In doing so, the parts of the outer sealing ring are shifted radially to the housing of the gas turbine and then are joined to the outer sealing ring, in particular being braced and/or connected in a form-fitting manner in the circumferential direction (see FIG. 2C with the opposite direction of the arrow). This radial shift is superimposed on the axial displacement of the entire outer sealing ring or the outer sealing ring parts. In the last step (see FIG. 2B.fwdarw.FIG. 2A) in particular, the complete outer sealing ring is displaced axially in the direction of flow, so that the radial protrusions 3.1 on the housing engage in the axial grooves in the outer sealing ring, thereby securing it and/or attaching it by the C ring in the circumferential direction and in the direction of flow in addition to the friction-locking effect.

(29) After the radial and axial displacing and joining of the outer sealing ring parts, the outer sealing ring 27 is detachably attached to the housing 3 by placing the C ring 45 in position, bracing the outer sealing ring and the housing in a friction-locking manner and displacing the rotor 19 axially against the direction of flow (see FIG. 2B, with the direction of the arrow reversed).

(30) Next the tool 101-106 is released and the connecting flange 9 is detachably connected to the housing 3.

(31) FIG. 3 shows, in a diagram corresponding to FIG. 2, a part of a gas turbine according to another embodiment of the present invention. FIG. 4 shows an enlarged detail of a friction contact surface between the outer sealing ring and the housing, and FIG. 5 shows a section along V-V in FIG. 4. Corresponding elements are labeled with identical reference numerals, so that reference may be made to the description above and only differences will be discussed below.

(32) In the embodiment in FIGS. 3-5, the outer sealing ring 27 is also attached to the housing 3 by the C ring 45 in a friction-locking and releasable manner, but without a form-fitting connection. After releasing the C ring, the outer sealing ring can be displaced axially against the direction of flow (toward the left in FIG. 3) without thereby being hindered by a stop on the friction contact surface between the outer sealing ring and the housing.

(33) In contrast with the embodiment of FIG. 2, in the embodiment in FIGS. 3-5, as shown in particular in the sectional view in FIG. 5, the outer circumferential surface of the outer sealing ring 27 has a plurality of radial protrusions 27.1 for friction-locking connection to the inside circumferential surface of the housing 3, which is opposite the former radially, these radial protrusions extending radially outward and engaging in axial grooves 3.2 in an end face of the housing, which is at the front in the direction of flow (at the left in FIGS. 3-5), in order to secure and/or fasten the outer sealing ring in the circumferential direction and in the direction of flow in a form-fitting manner on the housing.

(34) As also discernible in the sectional view in FIG. 5 in particular, the extent of the radial protrusions 27.1 is larger in the circumferential direction than the distance between two neighboring walls in the circumferential direction of axial grooves 3.2, which are neighboring in the circumferential direction. To this extent, the terms “groove” and “protrusion” do not constitute any restriction on generality, because in the case of a plurality of grooves and protrusions distributed in the circumferential direction, one or the other may be regarded as a groove or as a protrusion.

(35) Although exemplary embodiments have been explained in the preceding description, it should be pointed out that a number of modifications are also possible. Furthermore, it should be pointed out that that the exemplary embodiments are merely examples which should not restrict the scope of protection, the applications and the structure in any way. Instead, a guideline for implementation of at least one exemplary embodiment is provided by the preceding description for those skilled in the art, but various modifications in particular with regard to the function and arrangement of the components described here may be made without going beyond the scope of protection, as defined by the claims, and combinations of features that are equivalent to these.

LIST OF REFERENCE NUMERALS

(36) 1 low-pressure gas turbine 3 housing 3.1 radial protrusion 3.2 axial groove 5 channel 7 outlet housing 9 connecting flange 11, 13, 15, 17 guide baffle 19 front rotor 19a radial flange 21, 23, 25 additional rear rotor 27, 29, 31, 33 outer sealing ring 27.1 radial protrusion 45 C ring (connection) 59 honeycomb seal abradable coating 101 radial flange on the tool 102 axial web on the tool 103-106 fasteners on the tool d.sub.5 minimum inside diameter of channel 5 of the housing 3 D.sub.19 maximum outside diameter of the front rotor 19 d.sub.27 minimum inside diameter of the outer sealing ring 27 D.sub.27 maximum outside diameter of the outer sealing ring 27

(37) As also discussed above, the foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.