Bearing Arrangement Axial Thrust Load Management
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Solution Overview
Problem
Gas turbine engines face axial thrust loads due to pressure imbalances, which can cause high and uncertain thrust loads, particularly during maximum power output, leading to potential skidding of roller elements in thrust bearings, resulting in wear and reduced operational efficiency.
Innovation Solution
A bearing arrangement comprising two non-load sharing bearings with a member providing indirect forces to prevent skidding, using a fluid, magnetic, or mechanical mechanism to apply forces to the outer races, allowing for axial movement and varying forces to manage loads in different directions, and a controller to adjust forces based on skidding detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single thrust bearing is used to support the shaft against axial thrust loads, then the bearing structure is simple, but the roller elements may skid under high and uncertain thrust loads, resulting in wear and reduced reliability
Solution Approach 1:
The single thrust bearing is divided into two separate thrust bearings (first and second bearings) with different orientations. Each bearing handles thrust loads in a specific direction, preventing roller element skidding by ensuring loads are always within the designed bearing orientation. This segmentation resolves the contradiction by improving reliability through specialized load handling while keeping each individual bearing structure relatively simple.
2Reliability
If two non-load sharing bearings are used to prevent roller element skidding, then the reliability improves, but the device complexity increases
Solution Approach 1:
A movable component is introduced as an intermediary between the two thrust bearings and the shaft. This component allows the bearings to be positioned at different locations and oriented differently, with each bearing handling thrust in its optimal direction. The intermediary enables the system to achieve high reliability through proper load distribution while managing complexity by allowing flexible, non-load-sharing configuration where each bearing operates independently in its designed orientation.
3Force
If thrust bearings are designed to handle maximum power output loads, then the bearing capacity is sufficient, but the bearing size and mass increase, leading to higher energy consumption
Solution Approach 1:
The total thrust load capacity requirement is segmented between two smaller bearings instead of one large bearing. Each bearing is sized to handle a portion of the maximum thrust load in its specific orientation, reducing the size and mass of individual bearings. This segmentation allows the system to achieve the required total force capacity while reducing the energy consumption associated with larger, more massive bearing components.
4Adaptability or versatility
If the bearing arrangement allows axial movement of outer races, then the ability to manage loads in different directions improves, but the manufacturing precision requirements increase
Solution Approach 1:
The outer races are designed with axial movability rather than being fixed in position. This dynamic capability allows each bearing's outer race to move axially to accommodate thrust loads in different directions, providing adaptability to varying load conditions. The movability compensates for manufacturing tolerances and allows the bearing assembly to self-adjust, reducing the stringency of manufacturing precision requirements while maintaining excellent load direction management capability.
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 skidding and wear in the bearings, increases maintenance intervals, and allows for unequal bearing masses and sizes, reducing costs and energy consumption while maintaining efficient load management.
Implementation Method 1
The fluid may be a liquid and the indirect first force may be provided hydraulically
Implementation Method 2
The fluid may be a gas and the indirect first force may be provided pneumatically
Implementation Method 3
The member may comprise an electromagnet configured to generate a magnetic field to magnetically repel the first outer race and provide the indirect first force
Data Source
AI summary
A bearing arrangement comprising: a first bearing including a first inner race coupled to a rotatable component, a first outer race; and a plurality of first roller elements between the first inner race and the first outer race; a second bearing including a second inner race coupled to the rotatable component, a second outer race, and a plurality of second roller elements between the second inner race and the second outer race; a component, the first outer race being axially moveable relative to the component; and a member between the first bearing and the second bearing and arranged to provide an indirect first force on the first outer race to prevent the first roller elements from skidding when the first bearing and the second bearing receive a second force in a first direction, the second bearing being configured to transfer the second force to the component.