Conical Foil Bearing With Variable Stiffness for Combined Load Support
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conical foil bearings in turbomachinery face limitations in supporting dynamic operational loads due to uniform spring stiffness in existing cylindrical designs, which restrict their capability to handle both radial and axial loads effectively.
Innovation Solution
A conical bearing design featuring a bearing sleeve with a non-circular profile, a bump foil with varying stiffness, and a top foil, where the bump foil and top foil are segmented and axially split to enhance load distribution and stiffness control, integrated with additive manufacturing features like support slots, dovetails, and cooling channels for improved load capacity and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If uniform spring stiffness is used in cylindrical foil bearing designs, then the structure is simple and easy to manufacture, but the capability to support dynamic operational loads is limited
Solution Approach 1:
The bump foil is designed with non-uniform spring stiffness distribution, where the stiffness varies along the circumferential direction. This allows different regions of the bearing to have optimized stiffness characteristics for supporting dynamic radial and axial loads, rather than using uniform stiffness throughout the entire bearing structure.
Solution Approach 2:
The bearing is divided into multiple functional components including the bearing sleeve, bump foil with varying stiffness, and top foil. The bump foil itself is segmented into regions with different stiffness properties, allowing independent optimization of each segment for specific load conditions.
2Adaptability or versatility
If conical bearing design is used to support both radial and axial loads, then the need for separate thrust bearings is eliminated, but the bearing complexity increases
Solution Approach 1:
The conical foil bearing is designed to perform multiple functions simultaneously - supporting both radial loads and axial loads within a single bearing unit. The conical geometry and non-uniform stiffness distribution enable the bearing to adapt to different load directions and magnitudes, eliminating the need for separate journal and thrust bearings.
Solution Approach 2:
The design merges the functions of radial load support and axial load support into a single integrated conical bearing structure. The bearing sleeve, bump foil, and top foil work together as a unified system that can handle combined radial and axial loading conditions.
3Force
If cylindrical bore is used on either end of the sleeve, then the manufacturing is simplified, but the capability to support dynamic operational loads is reduced
Solution Approach 1:
The bearing sleeve features a non-circular interior surface profile with varying geometry along its length, optimized for different load conditions. The conical shape with tapered walls provides enhanced load distribution and stiffness characteristics compared to uniform cylindrical bores, while the specific geometric variations are tailored to support dynamic operational loads.
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 design effectively supports both radial and axial loads by varying stiffness along the circumference, reducing deformation and eliminating the need for thrust bearings, thus enhancing the bearing's load capacity and reliability while allowing for scalable applications in aerospace and non-aerospace sectors.
Implementation Method 1
Each bump foil pad segment comprises a plurality of foil bumps and the plurality of foil bumps varies in stiffness along a circumference of the bump foil
Implementation Method 2
A conical bearing includes a bearing sleeve, a bump foil, and a top foil. The bearing sleeve extends along an axis from a first open end to a second open end. The bearing sleeve has an axially tapered shape
Data Source
AI summary
A conical bearing includes a bearing sleeve, a bump foil, and a top foil. The bearing sleeve extends along an axis from a first open end to a second open end. The bearing sleeve has an axially tapered shape such that a first diameter of the bearing sleeve is greater than a second diameter of the bearing sleeve. An interior surface of the bearing sleeve has a non-circular profile. The bump foil is concentrically disposed within the bearing sleeve and includes bump foil pad segments extending circumferentially about the interior surface of the bearing sleeve. Each bump foil pad segment comprises a plurality of foil bumps and the plurality of foil bumps varies in stiffness along a circumference of the bump foil. The top foil is concentrically disposed within the bump foil and includes top foil pad segments extending circumferentially about an interior surface of the bump foil.