Annular Spring Element Clamping Variable Turbine Geometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing turbocharger devices with variable turbine geometry face challenges in maintaining optimal functionality due to high thermal loads, which can lead to reduced clamping forces from spring elements, causing increased deformation and inefficiency, especially under high exhaust gas temperatures.
Innovation Solution
An annular spring element with a radial outer flange and protruding tabs is used to center and clamp the guide device, separating the heat shield and spring functions, and is designed to maintain even force distribution and reduce thermal expansion effects, ensuring efficient blade gap management across the operating range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a spring element is used to clamp the guide device against the turbine housing, then axial positioning is achieved, but under high exhaust gas temperatures the spring element cannot exert sufficient clamping force
Solution Approach 1:
The spring element is segmented into multiple tabs extending radially inwardly from the outer flange. Each tab independently contacts the guide device, distributing the clamping force across multiple contact points. This segmentation allows the spring element to maintain effective clamping force under thermal expansion conditions, as the distributed contact points accommodate differential expansion better than a single contact point would.
Solution Approach 2:
The spring element transitions from a conventional linear spring configuration to an annular structure with radial tabs, utilizing the radial dimension to apply clamping force. The tabs extend radially inwardly from the outer flange to contact the guide device, creating a distributed radial clamping force that effectively positions the guide device axially while accommodating thermal effects.
2Force
If the spring element rests radially inwardly on the bearing housing and radially outwardly on the guide device, then clamping is achieved, but thermal expansion causes force loss
Solution Approach 1:
The spring element features localized contact surfaces through the tabs that extend radially inwardly to contact specific regions of the guide device. This local quality allows differential thermal expansion between the bearing housing, spring element, and guide device to be accommodated at each contact point independently, preventing force loss that would occur with rigid, extended contact surfaces.
Solution Approach 2:
The spring element is designed to utilize and accommodate thermal expansion of its components. The annular structure with radially extending tabs allows the material to expand thermally while maintaining contact force through the elastic properties of the spring. The tabs can deflect independently to accommodate expansion, ensuring continuous clamping force without loss.
3Device complexity
If a one-piece cup spring is used, then simple structure is achieved, but optimal force distribution under thermal load is not possible
Solution Approach 1:
The spring element is segmented into multiple tabs extending from the annular outer flange, with each tab providing an independent contact point on the guide device. This segmentation enables optimized force distribution across multiple locations, improving clamping effectiveness under thermal load while maintaining a relatively simple overall structure that integrates with the bearing housing and turbine housing.
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 minimizes load on the spring element, maintains consistent clamping force, reduces deformation, and enhances efficiency by ensuring a more even blade gap, leading to improved performance and reduced force loss due to thermal expansion.
Implementation Method 1
The spring properties of the component can compensate for deformations in the entire system (due to external forces or thermal expansion)
Implementation Method 2
because of the demand for higher exhaust gas temperatures, the individual components are subjected to increasing thermal load
Data Source
AI summary
A turbocharger device includes an annular spring element for axially clamping a guide device of a variable turbine geometry against a turbine housing. The annular spring element rests radially outwardly on the bearing housing and radially inwardly on a component of the guide device. The spring element has an annular radial outer flange in contact with the bearing housing, and a plurality of tabs which extend from the outer flange radially inwardly in the direction of the guide device and come into contact with a component thereof. An annular spring element for such a turbocharger is also provided.