Thrust Foil Bearing Assembly Without Weld-Induced Foil Distortion

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Solution Overview

Problem

Conventional thrust foil bearings face issues with top foil deformation due to welding, leading to distorted fluid lubricating films and reduced load capacity, as the top foil may fall off the base plate and deform under heat during the welding process.

Innovation Solution

The thrust foil bearing employs a method of attaching the top foil through sandwiching, using a bearing spacer and fastening bolts to secure the top and back foils to the base plate without welding, preventing deformation and maintaining load capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If welding is used to attach the top foil to the base plate, then the top foil is securely fixed and will not fall off, but the top foil may be deformed due to heat causing distortion

Engineering Contradiction:
Improveattachment strengthVSAvoidtop foil flatness
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The harmful welding process is extracted and removed from the attachment method. Instead of welding, the patent uses a mechanical sandwiching structure with pressing members that apply pressure to secure the top foil without thermal input, thereby preventing heat-induced deformation while maintaining secure attachment

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A sandwiching structure with pressing members is introduced as an intermediary mechanism between the top foil and base plate. This intermediary applies mechanical pressure to secure the top foil in place without direct thermal contact, resolving the contradiction between secure attachment and prevention of heat deformation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the top foil is securely attached to prevent falling off, then reliability is improved, but the attachment method may cause deformation affecting fluid lubricating film formation

Engineering Contradiction:
Improvetop foil retentionVSAvoidmanufacturing quality
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The thermal-mechanical welding process is replaced with a purely mechanical sandwiching attachment system. Pressing members apply controlled mechanical pressure to secure the top foil without thermal input, ensuring both reliable retention and manufacturing quality by eliminating heat-induced distortion

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This method effectively limits top foil distortion and maintains the load capacity of the thrust foil bearing by securing the foils through sandwiching, preventing heat-induced deformation and ensuring stable fluid lubrication.

Implementation Method 1

The rotation of the thrust collar causes lubricating fluid to flow into a gap between the top foil piece and the thrust collar. The lubricating fluid forms a wedge-shaped fluid lubrication film between the top foil piece and the thrust collar, and the load capacity of the thrust foil bearing is obtained.

Methodology Applied
Scientific EffectHydrodynamic lubrication: Lubrication

Data Source

PatentEP3913242B1Thrust foil bearing
Publication Date: 2024.03.06 IHI CORP
  • EP3913242B1 patent drawingFigure 1~2
  • EP3913242B1 patent drawingFigure 3
  • EP3913242B1 patent drawingFigure 4

AI summary

A thrust foil bearing (3) includes: a base plate (30) including an insertion hole (30a) through which a shaft (1) is inserted; and a top foil (10) disposed around the insertion hole, wherein the top foil includes: a slit (17) dividing the top foil into an inner area and an outer area in a radial direction of the insertion hole; a sandwiched part (14) disposed in the outer area; an extending part (13) extending from the sandwiched part to the inner area; and an inclined part (12) being in the inner area, having an end on one side in a circumferential direction of the insertion hole connected to the extending part, extending from the extending part toward another side in the circumferential direction, and inclined with respect to a flat surface of the base plate extending a direction orthogonal to an axial direction of the insertion hole.