Variable-Pitch Blade Guiding Ring Radial Extension Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In turbomachines with variable-pitch blades, the existing inner ring designs face challenges in accommodating the radial extension of ferrules for sealing and supporting the blades, which limits space and complicates precise adjustment and assembly due to the intertwined rotor line and rectifier structures.
Innovation Solution
A guiding ring with radial orifices and sectors, featuring a radially inner crown and outer ferrule sectors connected via a circumferential sliding mechanism, reduces the radial extension by immobilizing sleeves, allowing for compact assembly and effective sealing, and includes abradable coatings for axial leak prevention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the radial extension of the inner ring is increased to accommodate ferrules for sealing, then sealing performance is improved, but the space available for blade pivot support is reduced
Solution Approach 1:
The inner ring is divided into two distinct functional zones: a radially inner crown sector for blade pivot support and a radially outer ferrule sector for sealing. This segmentation allows each zone to be optimized independently, with the crown sector providing blade support and the ferrule sector providing sealing, thereby resolving the space conflict between the two functions.
Solution Approach 2:
The patent utilizes the axial dimension to resolve the radial space conflict. The crown sector and ferrule sector are positioned at different radial locations, with the crown sector radially inside the ferrule sector. This spatial arrangement in the radial dimension allows both blade support and sealing functions to coexist without interfering with each other.
2Area of stationary object
If the inner ring structure is made more compact to reduce radial extension, then space is freed for sealing, but the complexity of assembly increases
Solution Approach 1:
The inner ring is segmented into a crown sector and a ferrule sector that can be manufactured and assembled separately. The crown sector with its blade pivot support features is assembled first, then the ferrule sector with sealing features is added to the radially outer position. This modular segmentation simplifies the overall assembly process while achieving a compact radial configuration.
3Manufacturing precision
If the inner ring is assembled after final mounting to ensure precise adjustment, then assembly precision is improved, but the mounting process becomes more complex and time-consuming
Solution Approach 1:
The inner ring is completely assembled with all its functional features (crown sector with blade pivots and ferrule sector with sealing) before the final mounting operation. This preliminary assembly allows for quality control and precision adjustment to be performed in a controlled manufacturing environment, and the completed assembly can then be installed as a single unit, thereby improving productivity without sacrificing precision.
Data Source
AI summary
A ring for guiding variable-pitch blades and supporting an abradable coating for an aircraft turbomachine ring extends about an axis (X) and includes substantially radial orifices for mounting guiding sleeves intended each to receive a pivot of one of the blades. The ring may include a radially inner crown divided into sectors and supports the abradable coating. A radially outer annular ferrule may be divided into sectors and include the orifices for mounting the sleeves. In some embodiments, each ferrule sector is mounted about a crown sector by a circumferential sliding connection. The crown sector may include an immobilizer for rotationally immobilizing the sleeves of this ferrule sector about the axis.