Gas Turbine Seal Assembly Relocation for Rotor Thrust Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gas turbine engines with tie shaft connections experience balance issues and large variations in rotor thrust due to the placement of seal assemblies at the radial outward portion of the separable shaft, leading to undesirable rotor thrust balance and high vibration levels.
Innovation Solution
The seal assembly is relocated to a portion of the separable shaft at least 80% of the shaft length away from the radial outward portion towards the radial inward portion, allowing a larger surface area to be subjected to higher pressures, thereby reducing rotor thrust variations and improving balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the seal assembly is placed at the radial outward portion of the separable shaft, then the seal assembly is easily accessible and installed, but large variations in rotor thrust balance and high vibration levels occur
Solution Approach 1:
A thrust balance weight is introduced as an intermediary component between the seal assembly and the separable shaft. This weight compensates for the thrust imbalance caused by the seal assembly's position at the radial outward portion, thereby resolving the contradiction between ease of installation and rotor thrust balance stability
Solution Approach 2:
The thrust balance weight functions as a counterweight to offset the thrust variations generated by the seal assembly's location. By positioning the seal assembly at the radial outward portion where it is easily accessible, the counterweight compensates for the resulting thrust imbalance, maintaining stable rotor operation
2Stability of the object's composition
If the seal assembly is relocated to a portion at least 80% of the shaft length away from the radial outward portion towards the radial inward portion, then rotor thrust balance is improved, but the seal assembly becomes less accessible
Solution Approach 1:
The seal assembly is positioned in the axial dimension at least 80% of the shaft length away from the radial outward portion towards the radial inward portion. This axial relocation improves rotor thrust balance while the thrust balance weight compensates for any accessibility issues, effectively resolving the contradiction through dimensional repositioning
3Stability of the object's composition
If a larger surface area of the separable shaft is subjected to higher pressures, then rotor thrust variations are reduced, but the structural complexity of the shaft increases
Solution Approach 1:
A larger surface area of the separable shaft is specifically designed to be subjected to higher pressures in the region at least 80% of the shaft length away from the radial outward portion. This localized pressure application reduces rotor thrust variations without requiring complex structural modifications throughout the entire shaft, as the pressure distribution is optimized in the specific region where the seal assembly is relocated
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 provides a more determinate and robust rotor thrust balance, reducing vibrations and ensuring a steady load on the ball bearing portion, while being tolerant to engine mission points and long-term seal wear.
Implementation Method 1
a seal assembly operable with a portion of the separable shaft proximate the radial inward portion
Implementation Method 2
the interface between the radial outward portion of the separable shaft and the last rotor stage includes a friction fit
Data Source
AI summary
A gas turbine engine defining a radial direction is provided. The gas turbine engine includes a tie shaft; a compressor section including a last rotor stage, the compressor section assembled to a first portion of the tie shaft; a separable shaft disposed between the compressor section and the tie shaft, the separable shaft having a radial outward portion and a radial inward portion, the radial outward portion of the separable shaft in contact with a portion of the last rotor stage at an interface; and a seal assembly operable with a portion of the separable shaft proximate the radial inward portion.