This application claims the priority of German Patent Document No. DE 10 2011 010 327.9, filed Feb. 4, 2011, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a ring element and to a turbomachine having such a ring element.
A vibration damping mechanism by means of ring elements may be provided in particular for damping and limiting the blade tilt of turbine blades in the compressor region of a gas turbine, such as for example an aircraft gas turbine. Ring elements of this type, such as for example damper rings or damper wires, are often accommodated in a groove of the component, the groove being formed, for example, in a rotor of a compressor. Ring elements have two adjacently arranged ring ends that are movable relative to one another and relative to the surrounding environment thereof in the ring groove.
Ring element arrangements of this type have the shortcoming that fretting occurs, in particular due to vibrations of the ring ends on both side surfaces of the ring groove that is provided for accommodating the ring elements and on adjacent components, such as for example the blade platform of a compressor blade. Moreover, the ring ends can move so as to extend into the gas flow path, thereby negatively impacting the flow conditions.
In view of the foregoing, it is the aim of the invention to create a ring element and a turbomachine having such a ring element, in which the wear of components in the region of the ring ends of the ring element is at least reduced.
The ring element according to the invention is provided preferably for accommodation in a ring groove, in particular of a turbomachine, such as for example an aircraft gas turbine, and has a ring element main body that has two adjacently arranged ring ends. According to the invention, the ring ends are connected to one another in a form-locking manner with respect to an axial plane. Wear of and damage to the component, such as in particular a compressor drum of an aircraft gas turbine, and adjacent components in the region of the ring ends, for example blade platforms of compressor blades, are at least greatly minimized because of the defined guidance of the ends. The operating safety is significantly improved as a result, and a longer component service life is attained. Because of the guided ring ends, the ring element can be arranged in the ring groove so as to freely rotate. The interconnection of the end sections prevents the ring ends from moving into the gas flow path. Furthermore, twisting of the ring ends, with the associated signs of wear and damage is prevented. Ring elements according to the invention may be provided as damper rings for vibration damping, in particular for damping and limiting the blade tilt of turbine blades in the compressor region of a gas turbine, such as for example an aircraft gas turbine. It is advantageous in this context that the damping behavior remains substantially unchanged also in the region of the ring ends since the damping mass in the connecting region of the ring ends changes only minimally. Additionally or alternatively, the ring elements may fulfill a holding function for blades that are inserted in axial grooves, and serve for axially securing the blades.
According to a particularly preferred embodiment of the invention, a first ring end has two guiding legs for approximately centrical accommodation of a guiding protrusion of a second ring end. As a result, the ring ends are guided according to the principle of a tongue-and-groove-connection in a form-locking manner with respect to the axial plane. Preferably, the side surfaces of an adjacent ring will end extend in common planes.
The guiding protrusion is provided preferably on the groove side with a bevel or rounding in the region of the end section. The bevel or rounding may be designed in such a way that the end section does not have any wear-promoting, sharp-edged contact with the groove bottom. In a preferred embodiment the guiding protrusion has an approximately rectangular cross section. The body edges may be rounded or beveled overall. This reduces or prevents wear of and damage to the contact partner.
The transition regions, such as for example the lateral transitions, between the ring element main body and the guiding protrusion are preferably provided with roundings or bevels. The radially outwardly situated surface of the guiding protrusion is provided in the region of the end section preferably with a rounding. With this solution, wear of and damage to the contact partner are further reduced.
It has proven particularly advantageous if the guiding legs extend substantially parallel to one another. The distance between the guiding legs in this arrangement corresponds substantially to the width of the guiding protrusion plus a slight clearance. In this manner an axially form-locking connection similar to a sliding fit is achieved that meets the high demands placed on the interconnection of the ring ends.
The end sections of the guiding legs are preferably provided with at least one bevel or a rounding, in particular on the inner radius, that is to say, radially inwardly and/or axially outwardly in the region of outer surfaces, such that signs of wear are at least reduced in this region as well.
In the installed state of the ring element, a gap is preferably formed between the ring element main body and each respective adjacently arranged ring end. Furthermore, it is advantageous if an overlap area of the ring ends is provided. Because of the gaps, the ring ends are slidable relative to one another in a tangential direction, such that the circumference of the ring element can be varied in a defined manner, the overlap area enabling a guided connection with minimized wear potential for the ring groove.
In a particularly preferred enhancement of the invention at least one ring end is held back radially. In this solution the ring ends are guided, in addition to the form-locking guidance with respect to the axial plane, also in the radial direction.
The guiding legs are preferably connected to one another by a radially outwardly situated connecting leg. As a result, the first ring end has an approximately U-shaped cross section for guiding the guiding protrusion of the second ring end. The minimized areas of contact permit a further reduction of the wear of adjacent components.
According to an advantageous embodiment of the invention, the guiding protrusion is designed tapered with respect to the ring width, preferably approximately step-like, with transition radii. The guiding protrusion preferably extends symmetrically to the centrical axial plane of the ring end.
A turbomachine according to the invention, in particular an aircraft gas turbine, includes at least one ring element according to the invention.
The ring element according to the invention may preferably be arranged between a blade platform and the rotor, in particular a compressor rotor. Preferably, at least one ring element is arranged axially in front of a row of blades and at least one ring element is arranged axially behind a row of blades of the compressor blade arrangement.
A preferred embodiment of the invention will be described below in conjunction with schematic drawings.
The ring elements 1 are arranged in the embodiment shown between a compressor rotor 6 and blade platforms 8 of compressor blades 10 for damping and limiting the blade tilt in such a way that each compressor stage has one ring element 1a associated therewith axially in front of a row of blades of the compressor blades 10 and one ring element 1b axially behind the row of blades of the compressor blade arrangement 10. The ring elements 1 each are arranged in an approximately U-shaped, radially outwardly open ring element groove 12a, 12b of the compressor rotor 6. This is explained by way of example in conjunction with the compressor stage shown in
As can be seen in particular from
According to
As can be seen particularly from
According to
As can be seen from
In the installed state of the ring element 1, a gap S1, S2 is formed, according to
Disclosed is a ring element 1 for a turbomachine, in particular for an aircraft gas turbine 4, having a ring element main body 14 that has two adjacently arranged ring ends 16, 18, the ring ends 16, 18 being connected to one another in a form-locking manner with respect to an axial plane 26. Also disclosed is a turbomachine having at least one such ring element 1.
1 ring element
2 high-pressure compressor
4 aircraft gas turbine
6 compressor rotor
8 blade platform
10 compressor blade
12 ring element groove
14 ring element main body
16 ring end
18 ring end
20 guiding leg
22 guiding leg
24 guiding protrusion
26 axial plane
28 transition region
30 surface
32 groove side
34 rounding
35 transition section
36 connecting leg
38 rounding
40 rounding
42 overlap area
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.
Number | Date | Country | Kind |
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10 2011 010 327.9 | Feb 2011 | DE | national |