Wastegate Plug Spheroidality for Turbocharger Sealing
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Solution Overview
Problem
Turbocharger wastegate systems face challenges in maintaining effective sealing and controllability due to high operational temperatures, leading to wear, leakage, and noise issues over the lifetime of the exhaust turbine assembly.
Innovation Solution
The implementation of a wastegate arm and plug design with a hemispherical shell portion and a biasing mechanism, such as a biasing cam, to enhance self-centering and reduce clearance between components, thereby improving controllability and longevity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional flat wastegate plug and seat design is used, then the structure is simple and easy to manufacture, but sealing effectiveness deteriorates under high temperature and vibration conditions
Solution Approach 1:
The patent applies spheroidality by replacing the traditional flat wastegate plug and seat surfaces with hemispherical surfaces. The plug includes a hemispherical sealing surface and the seat includes a corresponding hemispherical surface, creating a spherical joint arrangement. This curvature provides self-centering capability under thermal expansion and vibration, maintaining sealing effectiveness without requiring complex adjustment mechanisms.
2Object-affected harmful factors
If rigid control linkage joints are used, then the structure is simple, but noise and vibration increase due to clearance and impact
Solution Approach 1:
The patent changes the physical parameters of the control linkage joints by replacing rigid pinned connections with spherical joints that have controlled clearance. The spherical joints allow for thermal expansion and vibration absorption while maintaining proper alignment, reducing noise and vibration without adding complex damping mechanisms.
3Reliability
If conventional pinned control linkage joints are used, then manufacturing is easy, but wear and clearance increase under high temperature operation
Solution Approach 1:
The patent replaces conventional pinned joints with spherical joints in the control linkage. Each joint consists of a spherical protrusion on one component fitting into a spherical recess in another component. This spherical geometry provides self-aligning capability that compensates for thermal expansion and manufacturing tolerances, maintaining controllability while simplifying the manufacturing process compared to precision pinned connections.
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 reduces noise, vibration, and leakage by maintaining effective sealing and controllability of the wastegate system, even under high-temperature conditions, leading to improved performance and longevity of the turbocharger.
Implementation Method 1
a biasing element coupled to the pin and to the control link. The biasing element can apply force between a surface of the pin and a surface of an opening of the control rod
Data Source
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 disposed at least in part in the bore; a rotatable wastegate shaft received at least in part by the bushing; a wastegate plug that extends from the wastegate shaft; a control arm operatively coupled to the wastegate shaft; a control link operatively coupled to the control arm; a pin that forms a joint between the control arm and the control link; and a biasing element coupled to the pin and to the control link.