Journal Foil Bearing Insert Structure for Precise Pre-Load Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional foil bearing systems face challenges in precisely controlling pre-load on shafts and are inefficient to manufacture due to complex component dimensions and assembly difficulties.

Innovation Solution

A journal foil bearing system with a journal member having an internal groove and a foil support insert member that includes a spacer to maintain top foil ends separated, allowing for precise control of pre-load and simplified manufacturing by reducing the part count and assembly complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional foil bearing systems are used, then the bearing can support shaft rotation, but it is difficult to precisely control the pre-load applied to the shaft

Engineering Contradiction:
Improvepre-load control precisionVSAvoidbearing component complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The bearing system is divided into modular components: a foil support insert member with groove, separate top foil member, and biasing foil. This segmentation allows independent control and adjustment of each component's dimensions, enabling precise pre-load control while simplifying the overall manufacturing process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention enables precise control of pre-load by varying critical dimensions such as the groove depth, insert member thickness, and top foil thickness. By adjusting these parameters, the pre-load can be precisely tailored to specific application requirements without increasing device complexity.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If conventional foil bearing systems are used, then the bearing can provide support, but manufacturing is inefficient due to large part count and assembly difficulties

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidpart count and assembly complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The foil support insert member integrates multiple functions into a single component: it provides structural support, contains the groove for positioning the top foil ends, and works with the biasing foil to establish pre-load. This merging reduces the total part count and simplifies assembly while maintaining bearing performance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The insert member is pre-formed with the groove structure during manufacturing, which automatically positions and spaces the top foil ends correctly during assembly. This preliminary preparation eliminates complex alignment steps and reduces assembly time, thereby improving manufacturing efficiency.

Inventive Principle:
Principle #10Preliminary action

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 system achieves precise and selective control of pre-load on the shaft, enhancing operational spring stiffness while simplifying manufacturing and assembly processes, resulting in efficient and repeatable production.

Implementation Method 1

the foil(s) exert an inwardly directed radial pre-load against the shaft when at-rest

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a top foil member with at least one arch-bound top foil received radially between the at least one biasing foil and the shaft

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP4074996B1Journal foil bearing system with foil support insert member
Publication Date: 2024.02.14 GARRETT TRANSPORTATION I INC
  • EP4074996B1 patent drawingFigure 1
  • EP4074996B1 patent drawingFigure 2
  • EP4074996B1 patent drawingFigure 3

AI summary

A journal foil bearing system includes a journal member with a bore and an internal groove. The system includes a shaft received within the bore and supported for rotation relative to the journal member about an axis. The groove extends substantially along the axis. The system also includes at least one biasing foil and a top foil member with at least one arch-bound top foil. The top foil member has a top foil first end and a top foil second end. Additionally, the system includes a foil support insert member that is received within the groove. The foil support insert member includes a spacer member that is disposed between the top foil first and second ends. The spacer member maintains the top foil first and second ends separated, at least, at a distance.