Monoblock Wastegate Assembly for Turbocharger Sealing Alignment

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Solution Overview

Problem

The existing designs of turbine wastegates face challenges in maintaining effective sealing and control due to misalignment and wear caused by high temperatures and mechanical stresses, leading to leakage and reliability issues over the lifetime of the exhaust turbine assembly.

Innovation Solution

The implementation of a monoblock wastegate design with a toroidal plug and conical wastegate seat, along with in situ welding and the use of a resilient ring to fix the bushing and control arm, ensures precise alignment and self-centering, reducing axial play and leakage, and enhancing durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional separate components (plug, arm, shaft) are used in wastegate design, then ease of manufacture is improved, but reliability deteriorates due to misalignment and wear from high temperatures and mechanical stresses

Engineering Contradiction:
Improveease of manufactureVSAvoidreliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent combines the plug, arm, and shaft into a single monoblock wastegate component. This integration eliminates the interfaces between separate parts, preventing misalignment and wear that occur at connection points. The unified structure maintains reliability under high temperatures and mechanical stresses while remaining manufacturable through casting or forging processes.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If flat disk shaped plug with flat seat is used, then ease of manufacture is improved, but sealing efficiency deteriorates due to leakage under high pressure differential

Engineering Contradiction:
Improveease of manufactureVSAvoidsealing efficiency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent employs a toroidal (doughnut-shaped) plug with a conical seat instead of flat surfaces. The curved toroidal geometry allows the plug to self-center and maintain consistent contact with the conical seat under pressure, creating an effective seal that prevents exhaust leakage. This curved design is particularly effective under high pressure differentials while remaining compatible with standard manufacturing processes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Reliability

If oversized component design is used to meet reliability levels, then reliability is improved, but device complexity increases

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

By integrating the plug, arm, and shaft into one monoblock component, the patent achieves high reliability without oversizing individual elements. The unified structure eliminates weak points at interfaces between separate components, allowing the wastegate to meet reliability requirements with a compact, appropriately-sized design rather than requiring oversized parts for safety margins.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3736420B1Turbine housing assembly with wastegate
Publication Date: 2022.04.20 GARRETT TRANSPORTATION I INC
  • EP3736420B1 patent drawingFigure 1
  • EP3736420B1 patent drawingFigure 2
  • EP3736420B1 patent drawingFigure 3

AI summary

A method can include positioning a bushing in a bore of a turbine housing; positioning a shaft of a wastegate in a bore of the bushing where the shaft includes a shaft shoulder and a shaft end; applying force to a plug of the wastegate to substantially center the plug with respect to a wastegate seat of the turbine housing; positioning a ring at least in part in the bore of the bushing and between the shaft shoulder and the shaft end; and fixing the ring to the bushing.