Bearing-to-Seal Shield Layout for Uniform Rotor Seal Temperature
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Solution Overview
Problem
Turbine engine seal assemblies face issues with nonuniform 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
Incorporating an annular shield that blocks the line of sight between the rotor seal element and the lubrication fluid, reducing the amount of lubrication fluid that contacts the rotor seal element and maintaining a uniform temperature gradient by directing lubrication fluid away from the rotor seal element, thereby reducing coning and leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If lubrication oil is allowed to contact the rotor seal element for cooling, then the temperature of the rotor seal element is reduced, but the temperature distribution becomes nonuniform causing coning
Solution Approach 1:
A shield is introduced as an intermediary component between the bearing and the rotor seal element. The shield directs lubrication oil away from the rotor seal element while still allowing it to cool the bearing, preventing direct contact that would cause nonuniform temperature distribution and coning of the seal landing.
Solution Approach 2:
The space around the rotor seal element is segmented into different zones using the shield. The shield creates a separated flow path that directs cooling oil to specific areas (away from the rotor seal element) while maintaining necessary cooling of adjacent components, thus achieving uniform temperature distribution.
2Temperature
If lubrication oil contacts the rotor seal element, then cooling is provided, but leakage increases due to coning
Solution Approach 1:
The shield acts as a mediator that separates the lubrication oil flow from the rotor seal element contact area. This prevents the oil-induced temperature gradient that causes coning, thereby maintaining reliable sealing performance while still providing cooling to the bearing structure.
Solution Approach 2:
The shield creates localized control over where lubrication oil is applied. By directing oil away from the rotor seal element contact surface, the local temperature distribution is controlled to prevent coning, while cooling is maintained in other areas through the modified flow pattern.
3Temperature
If air and lubrication oil are used for heat transfer, then cooling is achieved, but nonuniform temperature gradient causes coning
Solution Approach 1:
The shield serves as an intermediary that modifies the heat transfer pathway. It allows air to provide heat transfer to the rotor seal element while preventing lubrication oil from creating excessive localized cooling, thereby achieving more uniform temperature distribution through controlled thermal management.
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 solution effectively reduces coning of the rotor seal element and minimizes leakage by maintaining a uniform temperature gradient, enhancing the sealing performance of the turbine engine assembly.
Implementation Method 1
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 2
A portion of relatively cool lubrication oil may travel axially from the bearing onto the aft side of the seal landing. This lubrication oil may transfer the heat energy out of and thereby cool the seal landing
Data Source
Figure 1
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AI summary
An assembly is provided that includes a shaft (44, 45), a bearing (46), a stator seal element (62), a rotor seal element (64) and a shield (58). The shaft (44, 45) extends along an axis. The bearing (46) supports the shaft (44, 45) and receives lubrication fluid. The stator seal element (62) circumscribes the shaft (44, 45). The rotor seal element (64) is mounted on the shaft (44, 45) axially between the bearing (46) and the stator seal element (62). The rotor seal element (64) forms a seal with the stator seal element (62). The shield (58) substantially prevents the lubrication fluid from traveling axially away from the bearing (46) onto the rotor seal element (64).