Bearing-to-Seal Shield Geometry to Prevent Rotor Seal Coning
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Solution Overview
Problem
Turbine engine seal assemblies face issues with non-uniform temperature gradients due to differing heat transfer coefficients of air and lubrication oil, leading to coning of the seal landing and increased leakage between the face seal and the seal landing.
Innovation Solution
A turbine engine assembly that includes a shield with a sleeve and flange configuration, which blocks the axial line of sight between the gap of the bearing races and the rotor seal element, preventing lubrication fluid from reaching the rotor seal element and maintaining a uniform temperature gradient.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If lubrication oil is allowed to cool the seal landing, then heat transfer from the hot air is reduced, but non-uniform temperature gradient is created causing coning
Solution Approach 1:
The patent introduces a shield as an intermediary component positioned between the bearing and the rotor seal element. This shield blocks the direct path of lubrication oil to the seal landing, preventing the oil from cooling the seal surface. By controlling where the cooling fluid acts, the shield maintains uniform temperature distribution across the seal landing while preventing coning and leakage.
2Temperature
If shield blocks lubrication fluid from rotor seal element, then temperature gradient uniformity is improved, but seal cooling efficiency is reduced
Solution Approach 1:
The shield creates localized cooling zones by blocking lubrication oil from reaching specific areas (the seal landing) while allowing cooling to occur in other regions. This selective cooling approach ensures that the seal surface maintains uniform temperature without excessive cooling that would cause coning, while the system still benefits from overall heat dissipation through other pathways.
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 shield configuration reduces coning of the rotor seal element by minimizing heat transfer from lubrication fluid, thereby reducing leakage and maintaining a uniform temperature gradient, enhancing the sealing efficiency of the turbine engine.
Implementation Method 1
The shield substantially blocks an axial line of sight between the gap and the rotor seal element
Implementation Method 2
A portion of this air may be directed into passages within the face seal to provide a film of air between the face seal and the seal landing. Heat energy may be transferred from the air into the seal landing
Implementation Method 3
the aft side of the seal landing may become significantly cooler than the forward side. The seal landing therefore may be subject to a relatively non-uniform temperature gradient
Data Source
AI summary
An assembly is provided that includes a shaft, a bearing, a stator seal element, a rotor seal element and a shield. The shaft extends along an axis. The bearing supports the shaft and receives lubrication fluid. The stator seal element circumscribes the shaft. The rotor seal element is mounted on the shaft axially between the bearing and the stator seal element. The rotor seal element forms a seal with the stator seal element. The shield substantially prevents the lubrication fluid from traveling axially away from the bearing onto the rotor seal element.