Aircraft Turbomachine Rotor Damping Device Radial Force
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Solution Overview
Problem
Existing damping solutions for aircraft turbomachine rotor blades cause wear by moving axially and contacting downstream rotor disks, leading to increased wear on blade mounting feet and rotor disks, and fail to effectively reduce relative movements between blades and housings.
Innovation Solution
A damping device comprising a support ring and integral damping members that extend under blade platforms to exert a radial force, reducing relative movements and wear by being connected to a support ring that limits axial movement, with damping members being pre-stressed to provide optimal plating and distributed uniformly around the circumference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a shim made of viscoelastic material is wrapped around the blade mounting foot to absorb relative movements, then wear is reduced, but axial movement occurs causing contact with downstream rotor disc increasing wear
Solution Approach 1:
The damping element is configured to act primarily in the radial direction rather than axially. By extending radially from the rotor disc to contact the blade platform, the damping element absorbs relative movements through radial compression while its axial positioning (held between rotor discs) prevents the axial movement that plagued previous shim solutions.
Solution Approach 2:
The damping element serves as an intermediary component positioned between the rotor disc and blade platform. It mediates the relative movements by deforming radially while being constrained axially, thus protecting both the mounting foot and downstream rotor disc from direct contact and wear.
2Reliability
If a damper with spring connecting base and weight is used to limit relative movement, then wear is reduced, but axial movement occurs causing contact with downstream rotor disc
Solution Approach 1:
The invention extracts the essential damping function from complex assemblies (shims, weight-spring dampers) and implements it through a simpler radial spring element. The damping action is achieved by the radial compression of the spring element between the rotor disc and blade platform, eliminating the axial movement problem while maintaining wear protection.
Solution Approach 2:
The damping mechanism changes from axial compression (in shims and weight-spring dampers) to radial compression. The spring element is pre-compressed in the radial direction and absorbs relative movements through radial deformation, fundamentally changing the direction of the damping action to prevent axial contact.
3Manufacturing precision
If locking shims are mounted in housings beneath blade roots to prevent relative movement, then blade positioning is improved, but wear is not effectively reduced
Solution Approach 1:
The locking shims provide rigid, fixed positioning but allow no movement absorption. The damping element introduces dynamic compliance by using a spring mechanism that can deform radially, allowing the blade platform to move slightly relative to the rotor disc while maintaining secure positioning and reducing wear through controlled deformation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces relative movements between rotor blades and their housings, minimizing wear and improving the tightness of the rotor, while maintaining a low mass and cost, and preventing downstream movement of the damping device, thus extending the lifespan of the rotor components.
Implementation Method 1
each damping element being configured to extend under at least one platform of a blade so as to exert a radial force to dampen the radial displacement of the blade
Implementation Method 2
damping members being pre-stressed to provide optimal plating
Data Source
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AI summary
An aircraft turbomachine rotor (2) comprising a rotor disc (20) extending transversely with respect to a longitudinal axis X, a plurality of blades (21) and a damping device (1) comprising: a support ring (7) configured to extend transversely with respect to the longitudinal axis X and configured to be mounted on the outer periphery of the rotor disc (20), and a plurality of damping members (8) that are secured to the support ring (7) and extend projecting upstream from the support ring (7), each damping member (8) being configured to extend at least under a platform (211) of a blade (21) so as to exert a radially outward force so as to damp the radial movement of said blade (21) when the turbomachine is in operation.