Arrangement for reducing oscillation

Patent metadata

Field	Value
Publication number	US-11905850-B2
Application number	US-202217743479-A
Country	US
Kind code	B2
Filing date	May 13, 2022
Priority date	May 20, 2021
Publication date	Feb 20, 2024
Grant date	Feb 20, 2024

Abstract

An arrangement reduces oscillation (vibration) of an oscillatory structure. The arrangement has a structure having at least one mode in at least one direction; and an oscillation-reducing device (vibration-reducing device). The oscillation-reducing devices has a housing formed by or provided on the structure, a cavity, and a body configured for making impact contacts with the housing and disposed in the cavity in such a manner that the body is configured to make impact contacts with the housing at least temporarily for as long as the structure is excited in the at least one mode in the at least on direction.

First claim

The invention claimed is:

1. An arrangement for reducing oscillation of an oscillatory structure, the arrangement comprising:
a structure having at least one mode in at least one direction; and
at least one oscillation-reducing device comprising at least one housing formed by or provided on the structure, a cavity, and at least one body configured for making impact contacts with the housing and disposed in the cavity in such a manner that the body is configured to make impact contacts with the housing at least temporarily for as long as the structure is excited in the at least one mode in the at least one direction, wherein:
a) for a clearance for movement B of the at least one body in the at least one direction in the cavity, it holds that:
0.1× A 0j <B< 0.95× A 0j ,

and/or
b) for a mass m i of the at least one body, it holds that:

m
i

<

μ
×

M

j
⁢
j

,

with
⁢

⁢
μ

=

a

(

A
⁢
1
⁢
j

A
⁢
0
⁢
j

)

2

,

 and 0.000001<a<0.0009,
where A 0j is an oscillation amplitude in the at least one mode without an oscillation-reducing device at a position at which the oscillation-reducing device is to be provided, during normal intended use of the structure,
where Mjj is a modal mass of the structure in the at least one mode, and
where A 1j is a maximum oscillation amplitude in the at least one mode during the normal intended use of the structure with the oscillation-reducing device at the position at which the oscillation-reducing device is to be provided.

2. The arrangement as recited in claim 1 wherein, by providing the oscillation-reducing device, the maximum oscillation amplitude in the at least one mode is reduced by at least 5%, 20%, 30%, 40% or 50% compared to the oscillation amplitude in the at least one mode without the oscillation-reducing device at the position at which the oscillation-reducing device is to be provided, during the normal intended use of the structure.

3. The arrangement as recited in claim 1 , wherein the structure is a rotor blade or a stator vane of a turbine or compressor stage of a turbomachine, a part or a portion of the turbomachine, a part or a portion of a motor, of a turbine, of a manufacturing machine, of an engine, of a propulsion system, of a construction, of a vehicle, of an aircraft, of a rocket, of a satellite, a part in contact therewith, or a portion in contact therewith.

4. The arrangement as recited in claim 1 , wherein a total mass of the at least one body is at least 100 times smaller than the structure's modal mass that oscillates in the respective mode and/or the modal mass oscillating in the respective mode is no more than 200000 times greater than the total mass of the at least one body.

5. The arrangement as recited in claim 1 , wherein the at least one oscillation-reducing device is disposed on the structure only in those regions where the oscillation amplitude in the at least one mode without the oscillation-reducing device in the respective region is at least 0.1% and/or no more than 100% of the maximum oscillation amplitude in the at least one mode without the oscillation-reducing device in the respective region.

6. The arrangement as recited in claim 1 , wherein the body comprises or is an ellipsoid, a sphere, a cylinder, or a cuboid.

7. The arrangement as recited in claim 1 , wherein a clearance for movement of the body in at least one direction is no more than 2 times a maximum cross-sectional dimension of the body and/or at least 0.05 times the maximum cross-sectional dimension of the body.

8. The arrangement as recited in claim 1 , wherein the structure is a turbine blade having a blade root, a connecting piece for connection to an airfoil, an upper shroud disposed on the connecting piece, and a lower shroud connecting the blade root and the connecting piece, and wherein the oscillation-reducing device is provided in or on the lower shroud and/or in or on the upper shroud and/or in or on the connecting piece.

9. The arrangement as recited in claim 1 , wherein the at least one body has a metallic or ceramic surface, and the cavity is bounded by metallic or ceramic surfaces, so that the impact contacts occur between metal and metal, between ceramic and ceramic, or between metal and ceramic.

10. The arrangement as recited in claim 1 , wherein the cavity is a closed cavity, and wherein the at least one body is configured to make impact contacts with the housing continuously for as long as the structure is excited in the at least one mode in the at least one direction.

11. The arrangement as recited in claim 1 , wherein the oscillation-reducing device comprises a plurality of bodies comprising the at least one body, wherein a total mass of all bodies of the oscillation-reducing device is at least 100 times, or at least 1000 times, or at least 10000 times smaller than the structure's modal mass that oscillates in the respective mode or the modal mass oscillating in the respective mode is no more than 200000 times, no more than 100000 times, or no more than 50000 times greater than the total mass of the all of the bodies.

12. The arrangement as recited in claim 1 , wherein the oscillation-reducing device comprises a plurality of bodies comprising the at least one body, wherein a clearance for movement of all of the bodies in all directions is no more than 2 times a maximum cross-sectional dimension of the bodies and/or at least 0.05 times the maximum cross-sectional dimension of the bodies.

Assignees

• MTU Aero Engines AG

Inventors

• Hartung Andreas
• Hackenberg Hans-Peter
• Krack Malte
• Theurich Timo

Classifications

• F01D5/225

  by shrouding · CPC title

• F01D5/22

  Blade-to-blade connections, {e.g. for damping vibrations} · CPC title

• F05D2250/241

  spherical · CPC title

• F05D2260/96

  Preventing, counteracting or reducing vibration or noise · CPC title

• F01D5/26 Primary

  Antivibration means not restricted to blade form or construction or to blade-to-blade connections {or to the use of particular materials} · CPC title