Turbine Wastegate Plug Toroidal Profile Sealing
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Solution Overview
Problem
Turbine wastegates in internal combustion engines face challenges in maintaining effective sealing and controllability due to high mechanical stresses and misalignment issues, leading to exhaust leakage and reliability concerns, especially under varying pressure differentials and high operational temperatures.
Innovation Solution
The design incorporates a wastegate plug with a toroidal and modified sphere profile that maintains contact with the wastegate seat, providing clearances that control exhaust flow and enhance controllability, even under angular and displacement misalignments, thereby reducing mechanical stresses and improving sealing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a flat disk shaped plug is used to seal against a flat wastegate seat, then the structure is simple and easy to manufacture, but sealing effectiveness deteriorates under high mechanical stresses and misalignment conditions
Solution Approach 1:
The patent applies spheroidality by replacing the flat disk-shaped plug with a plug featuring a spherical seating surface that contacts a conical wastegate seat. This curved geometry allows the plug to self-align and maintain effective sealing under high mechanical stresses and misalignment conditions, resolving the contradiction between manufacturing simplicity and sealing reliability.
2Reliability
If oversized component design is used to meet reliability levels under high mechanical stresses, then reliability improves, but device complexity and size increase
Solution Approach 1:
The spherical seating surface on the plug and conical wastegate seat create a geometric configuration that naturally distributes mechanical stresses more evenly across the contact area. This allows the components to be smaller while maintaining reliability under high stresses, eliminating the need for oversized design.
3Reliability
If a protruding portion extends into the exhaust bypass opening, then sealing force is improved, but exhaust leakage increases due to disrupted flow
Solution Approach 1:
The spherical seating surface concentrates sealing force at the optimal contact point with the conical seat, achieving effective sealing without requiring a protruding portion that would disrupt exhaust flow. The curved geometry provides sufficient sealing force while maintaining smooth flow paths.
Data Source
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AI summary
An assembly can include a turbine housing that includes a bore, a wastegate seat and a wastegate passage that extends to the wastegate seat; a bushing configured for receipt by the bore; a rotatable wastegate shaft configured for receipt by the bushing; a wastegate arm extending from the wastegate shaft; and a wastegate plug extending from the wastegate arm where the wastegate plug includes a profile, defined in part by a portion of a torus, for contacting the wastegate seat to cover the wastegate passage and, for example, defined in part by a portion of a modified sphere or a portion of a cone. Various other examples of devices, assemblies, systems, methods, etc., are also disclosed.