Segmented Conical Foil Bearing for Combined Radial and Axial Loads

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Solution Overview

Problem

Conventional foil journal bearings, particularly conical designs, struggle with limited capability to support dynamic operational loads due to uniform spring stiffness and require additional thrust bearings for axial load support.

Innovation Solution

A conical bearing design featuring a bearing sleeve with a non-circular profile, a bump foil with varying stiffness through foil bumps of different heights and pitches, and a top foil with segmented construction, allowing for improved load distribution and support through hydrodynamic pressure generation, combined with features like cooling channels and support slots or dovetails for enhanced assembly and cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If uniform spring stiffness is used in conical bearing design, then manufacturing is simplified, but capability to support dynamic operational loads is limited

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoiddynamic load support capability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by varying the spring stiffness of individual foil pads around the bearing circumference. Each pad can have different stiffness characteristics tailored to specific loading conditions at different angular positions, allowing the bearing to better support dynamic operational loads while maintaining manufacturability through modular pad construction

Inventive Principle:
Principle #3Local quality

2Force

If cylindrical journal bearing is used, then radial load support is achieved, but axial load support requires additional thrust bearings increasing device complexity

Engineering Contradiction:
Improveradial load supportVSAvoidnumber of bearing components
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent merges the functions of radial and axial load support into a single conical bearing component. The conical geometry with tapered bore allows the bearing to simultaneously support both radial loads (through the conical surface) and axial loads (through the end face), eliminating the need for separate thrust bearings and reducing overall device complexity

Inventive Principle:
Principle #5Merging (Combining)

3Force

If conical bearing with tapered bore is used, then both radial and axial loads are supported, but manufacturing precision requirements increase

Engineering Contradiction:
Improvecombined radial and axial load supportVSAvoidtapered bore geometry accuracy
Core Design Contradiction:
ForceVSManufacturing precision

Solution Approach 1:

The patent segments the bearing into multiple independent foil pads that can be manufactured separately and then assembled around the conical bore. This segmentation allows each pad to be manufactured with standard precision tolerances, avoiding the need to manufacture the entire tapered bore with high precision as a single piece, thereby reducing overall manufacturing precision requirements

Inventive Principle:
Principle #1Segmentation

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 efficiently supports both radial and axial loads without thrust bearings, reducing mass and complexity, and enhances load capacity and reliability by dynamically adjusting stiffness and incorporating hybrid cooling mechanisms.

Implementation Method 1

improved load distribution and support through hydrodynamic pressure generation

Methodology Applied
Scientific EffectHydrodynamic pressure generation: Lubrication

Data Source

PatentEP4411157B1Multipad hybrid conical foil bearing
Publication Date: 2025.08.27 HAMILTON SUNDSTRAND CORP
  • EP4411157B1 patent drawingFigure 1A~2
  • EP4411157B1 patent drawingFigure 3A~3C
  • EP4411157B1 patent drawingFigure 4A~4B

AI summary

A conical bearing (100) includes a bearing sleeve (104), a bump foil (106), and a top foil (108). The bearing sleeve (104) extends along an axis from a first open end (134) to a second open end (136). The bearing sleeve (104) has an axially tapered shape such that a first diameter of the bearing sleeve (104) is greater than a second diameter of the bearing sleeve (104). An interior surface (150) of the bearing sleeve (104) has a non-circular profile. The bump foil (106) is concentrically disposed within the bearing sleeve (104) and includes bump foil pad segments (128) extending circumferentially about the interior surface (150) of the bearing sleeve (104). Each bump foil pad segment (128) comprises a plurality of foil bumps (320) and the plurality of foil bumps (320) varies in stiffness along a circumference of the bump foil (106). The top foil (108) is concentrically disposed within the bump foil (106) and includes top foil pad segments (130) extending circumferentially about an interior surface (154) of the bump foil (106).