Turbocharger Outer Ring Grooves for Oil Film Damper Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In rotating machines, such as turbochargers, there is a risk of oil leakage from the outer ring, which compromises the function of the oil film damper, leading to instability and inefficiency.

Innovation Solution

The implementation of a rotating machine design featuring grooves on the outer ring and housing that guide oil towards supply holes, preventing leakage by directing oil flow towards the first oil supply hole, thereby maintaining a stable oil film damper function.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If oil is supplied between the inner peripheral surface of the housing and the outer peripheral surface of the outer ring, then the oil film damper function is achieved, but the oil may leak from the end of the outer ring to the outside

Engineering Contradiction:
Improveoil film damper functionVSAvoidoil leakage
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

A groove portion is introduced as an intermediary structure on the outer ring to intercept and redirect oil flow. The groove acts as a mediator between the oil supply and the outer ring end, preventing direct leakage while maintaining the oil film damper function in the clearance space.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful oil leakage path is extracted and redirected by the groove portion. The groove separates the oil flow from the leakage path at the outer ring end, extracting the oil from the harmful trajectory and redirecting it back toward the oil supply hole.

Inventive Principle:
Principle #2Taking out (Extraction)

2Loss of substance

If the groove portion is formed on the outer ring or housing to guide oil, then oil leakage is suppressed, but the device complexity increases

Engineering Contradiction:
Improveoil leakage suppressionVSAvoidstructure complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The outer ring or housing surface is segmented by adding a groove portion, dividing the surface into functional zones: the groove area for oil guidance and the remaining area for structural integrity. This segmentation enables oil control without requiring complete redesign of the entire component.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The groove portion is locally formed only where needed on the outer ring or housing to guide oil flow. This local modification approach maintains the overall simplicity of the device while providing targeted oil control functionality at the critical leakage area.

Inventive Principle:
Principle #3Local quality

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 design effectively suppresses oil leakage from the outer ring, ensuring a stable oil film damper function and maintaining the turbocharger's operational stability.

Implementation Method 1

a groove portion, which guides the oil in a direction toward the first oil supply hole as the groove portion is directed to a rotation direction front side of the rotating shaft

Methodology Applied
Scientific EffectFluid flow guidance:

Implementation Method 2

a portion where the oil is disposed between the outer peripheral surface of the outer ring and the inner peripheral surface of the housing functions as oil film damper

Methodology Applied
Scientific EffectOil film formation: Lubrication

Data Source

PatentEP3760850B1Rotating machine and turbocharger
Publication Date: 2024.02.14 MITSUBISHI HEAVY IND ENGINE & TURBOCHARGER LTD
  • EP3760850B1 patent drawingFigure 1
  • EP3760850B1 patent drawingFigure 2
  • EP3760850B1 patent drawingFigure 3

AI summary

On an inner circumferential surface (25a) of a housing (25) opposed to an outer circumferential surface (37a, 37b) of an outer ring, toward a front side in a rotation direction (B) of a rotation shaft (21), a first groove (41H, 41I) is formed as a groove portion for guiding an oil (39) in a direction toward a first oil supply hole (41D, 41E).