Turbocharger Wastegate Plug Mesh for Scroll Leakage Sealing
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Solution Overview
Problem
Turbine wastegates in turbochargers face challenges in maintaining effective sealing and reducing exhaust leakage due to high mechanical stresses, temperature fluctuations, and pulsation-induced misalignment, leading to reliability concerns and reduced engine torque.
Innovation Solution
A mesh is integrated into the wastegate plug recess, which compresses between the plug and the divider wall, reducing exhaust flow across the gap and enhancing sealing by increasing the mesh's porosity in the closed state, thereby minimizing scroll-to-scroll leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a flat plug is used to seal the exhaust bypass opening, then the sealing force is sufficient under normal conditions, but exhaust leakage occurs under high mechanical stress and pulsation-induced misalignment
Solution Approach 1:
A mesh screen is attached to the plug surface, creating a porous sealing structure that blocks exhaust leakage more effectively than a solid flat surface. The mesh configuration with interconnected openings provides multiple sealing paths that adapt to surface irregularities and maintain seal integrity under high stress and pulsation conditions.
Solution Approach 2:
The sealing solution combines two different materials: the solid plug material (providing structural strength and positioning) and the mesh screen material (providing enhanced sealing capability). This composite approach leverages the advantages of both materials to overcome the limitations of using a single material for sealing under high-stress conditions.
2Reliability
If oversized components are designed to meet reliability levels under high mechanical stress, then reliability improves, but device complexity and size increase
Solution Approach 1:
The mesh screen provides enhanced sealing capability without requiring oversized plug dimensions. The porous structure distributes sealing forces across multiple contact points, allowing the use of appropriately sized (not oversized) plug components while maintaining reliability under high mechanical stress and pulsation conditions.
3Ease of manufacture
If a flat plug surface is used for sealing, then manufacturing is simple, but sealing effectiveness deteriorates under temperature fluctuations and pulsation
Solution Approach 1:
The mesh screen can be manufactured using standard mesh fabrication processes and attached to the plug, maintaining relative manufacturing simplicity. The mesh's flexible porous structure adapts to temperature-induced expansion and pulsation-induced misalignment, providing consistent sealing effectiveness across varying operational conditions without requiring complex manufacturing processes.
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 mesh solution effectively reduces scroll-to-scroll leakage, resulting in increased engine torque and improved turbocharger performance by maintaining effective sealing across varying operational conditions, including high temperatures.
Implementation Method 1
A mesh is integrated into the wastegate plug recess, which compresses between the plug and the divider wall, reducing exhaust flow across the gap
Data Source
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AI summary
An assembly (200,400,600,700) can include a turbine housing (210,510,610) that includes a bore (212), a wastegate seat ( 226,426,526,626) , wastegate passages (623) that extend to the wastegate seat and a divider wall ( 519,619) disposed between the wastegate passages where the divider wall includes a divider wall surface ( 417,517,617) ; a rotatable wastegate shaft (252,652,752) configured for receipt by the bore; a wastegate arm (254,654,754) extending from the wastegate shaft; and a wastegate plug (256,456, 656,756) extending from the wastegate arm where the wastegate plug includes a contact portion that contacts the wastegate seat to cover the wastegate passages in a closed state and a mesh ( 790,990) that contacts the divider wall surface in the closed state.