Wastegate Washer Bevel Reduces Spring Over-Compression
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Solution Overview
Problem
Wastegate assemblies in turbochargers face degradation due to high temperatures and corrosive exhaust gas, leading to reduced service life, particularly affecting biasing members like springs.
Innovation Solution
The wastegate assembly incorporates a washer with a beveled region that minimizes contact with the biasing member beyond a flat region, preventing over-compression and extending the service life by isolating compression to designed areas, and includes a configuration with a spindle, valve shaft, and biasing member to regulate exhaust gas flow effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the washer has a conventional flat surface design, then the assembly is simple to manufacture, but the biasing member experiences over-compression and reduced service life
Solution Approach 1:
The washer features a beveled region with a specific angle (e.g., 15-45 degrees) relative to the flat surface, creating localized geometric variation. This local quality change directs compression forces along the valve shaft rather than allowing radial over-compression of the biasing member, thereby extending its service life without requiring a complete redesign of the washer
2Productivity
If the biasing member is exposed to high temperatures and corrosive exhaust gas, then the wastegate assembly can perform its function, but the biasing member degrades and service life is reduced
Solution Approach 1:
The patent positions the biasing member within a protected environment by using the spindle head and washer structure to shield it from direct exposure to corrosive exhaust gas and extreme temperatures. The biasing member is extracted from the harsh external environment and placed in a more benign internal environment, allowing it to maintain its mechanical properties longer while the wastegate continues to function
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 over-compression of the biasing member, protects it from corrosive gases and high temperatures, and prolongs its service life by controlling compression points, thereby enhancing the durability and performance of the wastegate assembly.
Implementation Method 1
a biasing member (e.g. a spring)
Implementation Method 2
The beveled region extends oblique relative to the flat region for minimizing contact between the washer and the biasing member beyond the flat region
Data Source
AI summary
A wastegate assembly for controlling flow of exhaust gas includes a valve element having a valve body and a valve shaft. The wastegate assembly further includes a spindle having a head defining an opening and including a flat surface. The wastegate assembly further includes a washer coupled to the valve shaft and spaced from the spindle for securing the spindle to the valve shaft. The washer defines a bottom washer surface facing the flat surface of the spindle head, with the bottom washer surface including a flat region and a beveled region. A biasing member is disposed between the flat surface of the spindle and the flat and beveled regions of the washer. The beveled region extends oblique relative to the flat region for minimizing contact between the washer and the biasing member beyond the flat region.