Compressor Wheel Hub Asymmetry for Manufacturing Efficiency
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Solution Overview
Problem
Conventional compressor wheels for exhaust turbochargers are time-consuming to produce due to complex variable radiusing in the transition between the hub and blades, which increases manufacturing time and complexity.
Innovation Solution
A compressor wheel design featuring a hub with both rotationally symmetrical and non-rotationally symmetrical portions, where the transition between the hub and blades is achieved with a constant-radius connection, reducing production time and complexity by eliminating the need for variable radiusing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If variable radiusing is used in the transition between the hub and blades, then the durability of the compressor wheel is improved, but the manufacturing time and complexity increase significantly
Solution Approach 1:
The patent applies asymmetry by introducing a non-rotationally symmetrical portion in the hub region, which enables constant-radius blade connections while maintaining variable radiusing benefits. This asymmetric hub design allows the blades to connect with a constant radius on one side while the other side maintains the variable radiusing profile, thereby reducing manufacturing complexity without sacrificing durability
Solution Approach 2:
The patent applies local quality by implementing variable radiusing only in specific regions where it is most beneficial for durability, while using constant-radius connections in other regions to simplify manufacturing. The non-rotationally symmetrical portion allows different blade connection characteristics in different locations, optimizing both durability and manufacturability
2Duration of action of stationary object
If variable radiusing is used in the transition between the hub and blades, then the service life of the compressor wheel is extended, but the manufacturing complexity increases
Solution Approach 1:
The asymmetric hub design with a non-rotationally symmetrical portion allows the manufacturer to apply variable radiusing selectively in specific zones rather than throughout the entire hub-blade transition. This reduces the overall manufacturing complexity while preserving the service life benefits where variable radiusing is most effective
Solution Approach 2:
The hub is segmented into a rotationally symmetrical portion and a non-rotationally symmetrical portion, allowing different manufacturing approaches for different segments. This segmentation enables complex variable radiusing in critical areas while using simpler constant-radius connections in less critical areas, reducing overall manufacturing complexity
3Productivity
If constant-radius connection is used in the transition region, then the machining time is reduced, but the durability may be compromised compared to variable radiusing
Solution Approach 1:
The asymmetric hub design allows constant-radius connections to be used in regions where they provide sufficient durability while maintaining high machining speed, while variable radiusing is applied in critical regions where durability is paramount. This hybrid approach achieves both improved productivity and maintained reliability
Data Source
AI summary
A compressor wheel for a compressor of a turbocharger has a hub (16) and a multiplicity of blades (12) on the hub (16). In intermediate spaces of the multiplicity of blades (12), a channel is in each case formed between a suction side (24) and a pressure side (26). The channel guides fluid that flows in axially in relation to a rotation axis (22) radially or radially-axially outward. The hub (16) in relation to the rotation axis (22) in at least one channel is contoured with a rotationally symmetrical portion (18′) and a non-rotationally symmetrical portion (18). The non-rotationally symmetrical portion (18) is formed by radii that are variable in the flow direction, and a transition region (28) between the hub (16) and the blade (12) adjoins the non-rotationally symmetrical portion (18).