Variable Pitch Rectifier Inner Ring Connection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing variable pitch rectifiers for turbine engine compressors face challenges with radial spatial requirements and stiffness due to increased bolt spacing, particularly in 360° compressor architectures, leading to reduced performance and mechanical resistance.
Innovation Solution
The use of elastically deformable arc-shaped sectored stirrups as a connection device to grip the inner peripheral edges of upstream and downstream rings, reducing radial spatial requirements and improving stiffness without the need for bolts, while preserving the inner pivots of the vanes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bolts are used as connection device between upstream and downstream rings, then the rings can be assembled together, but the radial spatial requirement increases forcing rotor disc walls to be separated from gas flow circulation duct
Solution Approach 1:
The connection device is segmented into multiple identical modular units distributed around the circumference. Each unit comprises a stirrup element with specific geometric features that engage with corresponding features on the rings. This segmentation allows the connection function to be distributed while maintaining compact radial dimensions, as each modular unit only requires minimal radial space to function.
Solution Approach 2:
Instead of using bolts that extend radially outward from the ring assembly (conventional approach), the invention inverts the connection mechanism by having the stirrup elements engage from the inner peripheral edges of the rings. The connection features are positioned such that the stirrups clip the rings together without requiring additional radial space outward from the ring assembly, thereby reducing the overall radial spatial requirement.
2Ease of manufacture
If inner ends of rings are radially extended inwards to allow bolt assembly, then bolts can be installed, but the radial spatial requirement increases and abradable material supports are affected
Solution Approach 1:
The connection function and the sealing function are merged into a single integrated stirrup element. The stirrup not only connects the upstream and downstream rings but also provides mounting surfaces for abradable material supports. This merging eliminates the need for separate radial extensions of the rings, as the stirrup itself provides the necessary structural features for both connection and sealing purposes.
Solution Approach 2:
The invention changes the geometric parameters of the connection device by using elastically deformable stirrups with specific cross-sectional shapes (U-shaped, L-shaped, or channel-shaped). These parameter changes allow the stirrups to flex during assembly and then maintain a secure connection without requiring the rings to be radially extended. The elastic deformation capability enables easy installation while maintaining compact dimensions.
3Ease of manufacture
If arc-shaped elements assembled by elastically deformable stirrups are used, then connection is achieved, but the required stiffness is not provided
Solution Approach 1:
The stirrup elements are made from composite materials or composite structures that combine high elastic deformability with high structural stiffness. The stirrups may be constructed from spring steel or other elastic alloys that exhibit high yield strength and elastic modulus, allowing them to deform during assembly and then maintain rigid connections under operational loads. This composite material approach enables both easy assembly through elastic deformation and high structural stiffness during operation.
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 solution reduces the radial spatial requirement and enhances the stiffness of the compressor, allowing the rotor disc walls to be closer to the gas flow, and can be applied to both 360° and 180° compressor architectures, maintaining mechanical and aerodynamic performance.
Implementation Method 1
a device for connecting the rings comprising only one set of angular sectors of elastically deformable stirrups arranged so as to grip the inner peripheral edges of said upstream and downstream rings by clipping them together
Data Source
AI summary
A variable pitch rectifier for a compressor includes a plurality of radial vanes having respectively, at outer and inner ends of same, outer and inner pivots, the inner pivots being received between two upstream and downstream inner rings, which are assembled by a link device. The link device includes only a set of angular sectors of elastically deformable stirrups, arranged to grip together the inner peripheral edges of the upstream and downstream rings by clamping one against the other.