Thrust Bearing Housing Hinge Point for FBO Moment Loads
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Solution Overview
Problem
Existing thrust bearing housings in gas turbine engines are inadequate in supporting the increased loads during fan blade off (FBO) or foreign object damage (FOD) events, as they suffer from excessive material stress and damage due to lack of a hinge point, leading to buckling under massive moment loads.
Innovation Solution
The design incorporates a thrust bearing housing with a cone member connected to annular end members at circular junctions, creating a hinge point axially forward of the bearing flange and radially closer to the housing flange, providing increased flexibility and lower material stresses by positioning the major hinge point at a higher diameter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the thrust bearing housing uses a conventional design without a hinge point, then the structure is simpler, but the housing cannot sustain massive moment loads during FBO or FOD events, leading to buckling and excessive material stress
Solution Approach 1:
The thrust bearing housing is segmented into a conical portion and a radial portion that meet at a hinge point. This segmentation allows the structure to rotate or flex at the hinge point during FBO or FOD events, enabling the housing to sustain massive moment loads by distributing stresses more effectively rather than relying on a single rigid structure
Solution Approach 2:
The hinge point introduces dynamic flexibility to the thrust bearing housing. During abnormal events like FBO or FOD, the housing can rotate or flex at the hinge point, transforming from a static rigid structure to a dynamic structure that can adapt to extreme loading conditions, thereby sustaining massive moment loads without buckling
2Ease of manufacture
If the hinge point is positioned at the low diameter cone, then the manufacturing is easier, but the housing experiences excessive material stress and plastic strain exceeds material limits during FBO or FOD events
Solution Approach 1:
The hinge point is repositioned from the low diameter cone to a location on the bearing flange, representing a dimensional change in the structural configuration. This repositioning alters the stress distribution pattern during FBO or FOD events, moving the stress concentration away from the vulnerable low diameter cone area to a more robust location that can better withstand the applied loads
3Device complexity
If all hinging occurs on the same side of the flange as the bearing, then the structure is simpler, but the housing cannot effectively distribute moment loads, resulting in focused damage at the cone
Solution Approach 1:
The hinge point is positioned asymmetrically on the bearing flange rather than on the same side as the bearing. This asymmetric configuration allows the housing to distribute moment loads more effectively during FBO or FOD events, preventing focused damage at the cone by creating a more balanced stress distribution pattern across the flange structure
Data Source
AI summary
The thrust bearing housing comprises two opposite annular end members and a cone member extending between the two end members. The cone member is connected to each end member at a circular junction, each circular junction having a medial line which borders a respective end of a virtual conical plane. At least a major portion of the cone member is provided inside the virtual conical plane.