Lattice Impeller Structure for Lightweight Turbo-Machine Manufacturing
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Solution Overview
Problem
Manufacturing turbo-machine impellers, such as those for centrifugal compressors and centrifugal pumps, is complex and costly due to their intricate geometry, and they face challenges in weight reduction while maintaining mechanical and chemical resistance under high dynamic stresses and harsh environments.
Innovation Solution
The use of additive-manufacturing processes, specifically controlling a high energy source to create a lattice structure within bulk portions of the impeller surrounded by a solid skin, reducing thermal stresses and weight through controlled melting and solidification of powder material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional manufacturing processes (electrical discharge machining, full milling) are used to manufacture impellers with complex geometry and shrouds, then manufacturing precision and structural integrity are maintained, but manufacturing cost and complexity increase significantly
Solution Approach 1:
The patent changes the manufacturing approach from subtractive (machining) to additive (layer-by-layer construction) processes. This fundamental parameter change enables complex geometries including shrouds and internal lattice structures to be manufactured directly without requiring multiple machining operations, tool changes, or assembly steps, thereby reducing manufacturing complexity while maintaining precision
Solution Approach 2:
The patent segments the impeller manufacturing into discrete layers that are constructed sequentially. Each layer is built independently and then fused to the previous layer, allowing complex 3D geometries to be created through simple 2D layer patterns. This segmentation enables the production of intricate internal structures and shrouds that would be difficult or impossible to achieve with traditional machining
2Strength
If solid metal pieces are used to manufacture impellers to ensure mechanical strength under high dynamic stresses, then structural integrity is maintained, but impeller weight increases
Solution Approach 1:
The patent incorporates lattice structures with controlled porosity within the impeller body. These lattice structures provide sufficient mechanical strength to withstand high dynamic stresses while significantly reducing the overall material volume and weight compared to solid metal pieces. The lattice geometry is optimized to maintain structural integrity while minimizing weight
Solution Approach 2:
The patent uses additive manufacturing to create composite structures combining different materials or densities within the same impeller. The lattice regions may use different material properties than the solid outer shell, allowing optimization of both strength and weight. This composite approach enables the impeller to have varying density distributions tailored to mechanical requirements
3Weight of moving object
If additive manufacturing with lattice structures is used to reduce impeller weight, then weight reduction is achieved, but manufacturing precision and surface quality may deteriorate
Solution Approach 1:
The patent applies different structural qualities to different regions of the impeller. The outer shell and surface-critical areas are manufactured with high-density solid material to ensure smooth surfaces and precise dimensions, while internal non-critical regions use lattice structures for weight reduction. This local differentiation maintains manufacturing precision where needed while achieving weight reduction where possible
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 method enables efficient and cost-effective manufacturing of turbo-machine impellers with reduced weight and improved mechanical strength, while maintaining structural integrity and resistance to thermal and mechanical stresses.
Implementation Method 1
The powder material is irradiated and melted with a high energy source and solidifies to form the impeller
Implementation Method 2
In particularly advantageous embodiments, an electron-beam source is used. The electron beam generated by an electron-beam gun locally melts the powder material
Implementation Method 3
Subsequent cooling of the melted material generates the final structure of each layer of the turbo-machine impeller
Data Source
Figure 1~2
Figure 3
Figure 4~5(C)
AI summary
A turbo-machine impeller (120) is described, comprising a plurality of solidified layers formed by solidified powder material. The impeller comprises at least one portion made of a lattice structure (L) surrounded by a solid skin structure (S).