Centrifugal Compressor Impeller Nonlinear Backwall Stress Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing centrifugal compressor impellers with flat backwalls face challenges in stress and deflection performance, necessitating improved designs for enhanced efficiency and durability.
Innovation Solution
The implementation of a centrifugal compressor impeller with a nonlinear backwall, featuring a convex shape that includes a flat area, a compound curve with varying radii of curvature, and an inflection point, which reduces bore stress and deflection by altering the curvature distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a flat backwall design is used in centrifugal compressor impellers, then the manufacturing process is simple, but the stress and deflection performance deteriorates
Solution Approach 1:
The patent applies curvature to the backwall by introducing a convex portion with a defined radius of curvature. This curved geometry redistributes stress more effectively compared to a flat backwall, reducing bore stress and deflection while maintaining manufacturability through standard forming processes.
Solution Approach 2:
The convex portion is strategically positioned in the hub region of the impeller backwall, creating a localized structural enhancement. This local modification optimizes stress distribution precisely where needed (at the bore interface) without requiring complex changes to the entire backwall structure.
2Strength
If the backwall geometry is modified to improve stress distribution, then stress performance improves, but the device complexity increases
Solution Approach 1:
The backwall incorporates a single convex portion with a defined radius of curvature rather than complex multi-curved surfaces. This moderate curvature achieves improved stress distribution while avoiding excessive geometric complexity that would complicate manufacturing or design.
Solution Approach 2:
The convex portion is localized to the hub region rather than extending across the entire backwall. This localized modification improves stress distribution at critical areas while maintaining simplicity in other regions, thereby limiting overall device complexity.
Data Source
AI summary
A centrifugal compressor impeller includes a plurality of blades on a front side that extend from a first axial side to an outer radial end of the impeller. The centrifugal impeller includes a back side having a nonlinear backwall. The backwall can include a flat area hear a bore of impeller, a flat area near a tip of the impeller, and a convex surface between the flat areas of the bore and the tip. In some forms the impeller further includes a concave surface between the convex surface and the tip to form an s-shape. A transition or inflection point can denote the change from convex to concave. The convex and/or concave surfaces can take any variety of forms such as constant radius sections and/or compound curves.