Turbo-machine Vane Control Ring with Ball-Joint and Sliding Pivot Connections

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Solution Overview

Problem

Existing control devices for pivotable vanes in turbo-machines face precision and centering issues due to complex and precise movements, leading to potential jamming and high stress, exacerbated by thermal expansion differences, requiring stringent positioning and centering that increases weight and cost.

Innovation Solution

The use of ball-joint connections and sliding pivot connections to support the control ring portion, allowing for precise and reliable synchronized pivoting of vanes while minimizing off-center movements and reducing weight and wear, with a configuration of two ball-joint connections spaced 90° apart to distribute forces uniformly and utilize flexible links to absorb forces and prevent jamming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional pivot connections are used to control the ring portion, then the device structure is simple, but the device becomes statically indeterminate and jams due to precision clearance requirements

Engineering Contradiction:

Improvedevice operation reliabilityVSAvoidcontrol device structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The control device is segmented into multiple independent connection types: ball-joint connections for supporting the ring portion and sliding pivot connections for linking vanes to the ring. This segmentation allows each connection type to perform its specific function independently, avoiding the static indeterminacy that occurs when all connections are rigid pivots.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The sliding pivot connections introduce dynamic movement capability along the pivot axis, allowing the connections to adapt to thermal expansion and positioning variations. This dynamic characteristic prevents the device from becoming statically indeterminate while maintaining operational reliability.

Inventive Principle:

Principle #15Dynamics

2Measurement precision

If precision clearances are strictly maintained for centering the ring portion, then the control precision is improved, but the device becomes prone to jamming and requires additional centering systems

Engineering Contradiction:

Improvevane synchronization precisionVSAvoiddevice centering and positioning ease

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The invention changes the degrees of freedom parameters of the connections. Ball-joint connections provide three rotational degrees of freedom, while sliding pivot connections provide one rotational and one translational degree of freedom. This parameter change allows the system to achieve precise vane synchronization without requiring strict centering clearance control.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The sliding pivot connections act as intermediaries that accommodate positioning variations and thermal expansion between the ring portion and the vanes. These connections mediate the mechanical interactions, allowing precision to be maintained without requiring additional centering systems.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Manufacturing precision

If the ring portion is tightly constrained to prevent off-center movement, then the positioning accuracy is improved, but the mechanical stress and wear increase

Engineering Contradiction:

Improvering portion positioning accuracyVSAvoiddevice component strength

Core Design Contradiction:

Manufacturing precisionVSStrength

Solution Approach 1:

The sliding pivot connections allow the ring portion to dynamically adjust its position within acceptable tolerances, preventing excessive mechanical stress from building up due to tight constraints. This dynamic adjustment capability maintains positioning accuracy while reducing stress and wear on components.

Inventive Principle:

Principle #15Dynamics

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

This configuration enables precise and reliable control of vane pivoting, reduces the need for additional centering systems, results in a lighter and less expensive device with improved performance by minimizing mechanical stresses and wear, and enhances the precision of vane synchronization.

Implementation Method 1

at least two links are connected to the ring portion by respective ball-joint connections, with each of the other links being connected to the ring portion via respective sliding pivot connections

Methodology Applied

Scientific EffectBall-joint connection:

Implementation Method 2

each of the other links being connected to the ring portion via respective sliding pivot connections

Methodology Applied

Scientific EffectSliding pivot connection:

Implementation Method 3

utilize flexible links to absorb forces and prevent jamming

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS9551234B2Device for controlling pivotable vanes of a turbo-machine

Publication Date: 2017.01.24 SAFRAN HELICOPTER ENGINES

AI summary

A control device for controlling pivotable vanes of a turbo-machine, including: a plurality of pivotable vanes distributed in azimuth over at least 90° around the axis of the turbo-machine, the pivotable vanes being oriented substantially radially relative to the axis of the turbo-machine; and a control ring portion for controlling pivoting of the vanes, each vane being connected to the control ring portion by a link, the control ring portion being held around the axis of the turbo-machine by the links; wherein at least two of the links are connected to the ring portion by respective ball-joint connections, with other links being connected to the ring portion via respective sliding pivot connections.