Shrouded Rotor Hybrid Manufacturing for Machined Flow Surfaces

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Solution Overview

Problem

Existing methods for manufacturing shrouded rotors, such as those in air cycle machines, result in inefficiencies due to the need for clearance between rotor tips and a non-rotating shroud, limiting access for machining smooth flow surfaces and requiring separate fastening of the shroud, which complicates the manufacturing process.

Innovation Solution

A hybrid additive manufacturing process that constructs the shrouded rotor in stages, allowing for machining tools to access and smooth flow surfaces by forming each stage sequentially, with the shroud integral to the vanes and hub, eliminating the need for separate fastening and simplifying the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the shroud is fastened to the rotors through brazing, welding, bolts and nuts, rivets, or other fasteners, then the shroud can be securely attached to rotate with the rotors, but the manufacturing process becomes complex and time-consuming

Engineering Contradiction:
Improveshroud attachment strengthVSAvoidmanufacturing process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The shroud and rotors are merged into a single integral component through additive manufacturing, eliminating the need for separate fastening operations. The shroud is built directly onto the rotor assembly in a continuous manufacturing process, combining what were previously separate parts into one unified structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The additive manufacturing process serves multiple functions simultaneously: it builds the shroud structure, attaches it to the rotors, and creates the final integrated assembly in one process, replacing multiple separate manufacturing and assembly operations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Strength

If the shroud is fastened to the rotors through brazing, welding, bolts and nuts, rivets, or other fasteners, then the shroud can be securely attached to rotate with the rotors, but the manufacturing time and productivity are reduced

Engineering Contradiction:
Improveshroud attachment strengthVSAvoidmanufacturing efficiency
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The shroud and rotors are merged into a single integral component through additive manufacturing, eliminating the need for separate fastening operations. The shroud is built directly onto the rotor assembly in a continuous manufacturing process, combining what were previously separate parts into one unified structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The additive manufacturing process serves multiple functions simultaneously: it builds the shroud structure, attaches it to the rotors, and creates the final integrated assembly in one process, replacing multiple separate manufacturing and assembly operations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Volume of moving object

If the space within the shrouded rotor is limited, then the structure is compact, but tools cannot access to machine the flow surfaces adjacent the flow path

Engineering Contradiction:
Improveinternal spaceVSAvoidflow surface smoothness
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The additive manufacturing process builds the shroud and internal structures in a sequence that maintains tool access during construction. Support structures and build strategies are planned in advance to ensure machining tools can reach all flow surfaces before the final compact structure is complete.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Temporary support structures or fixtures are used during the additive manufacturing and machining process to provide tool access to internal flow surfaces. These intermediaries are removed after machining, leaving the final compact structure with smoothly finished surfaces.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The process enhances efficiency by ensuring smooth flow surfaces and reduces the rotor's mass and complexity, as vanes are supported at both ends, allowing for thinner designs and simplified assembly without additional fastening.

Implementation Method 1

A hybrid additive manufacturing process includes forming a first stage of a hub, depositing material to form a first stage of vanes and a first stage of a shroud

Methodology Applied
Scientific EffectAdditive manufacturing: 3D Printing

Implementation Method 2

machining an outer surface of the first stage of the hub to smooth the outer surface, depositing material on the first stage of the hub in a radial direction through a first stage of the vanes and the shroud, and machining all surfaces of the first stage of the vanes and an inner surface of the first stage of the shroud to smooth the surfaces

Methodology Applied
Scientific EffectMachining: Abrasion

Data Source

PatentEP3508304B1Hybrid additive manufacturing process for a shrouded rotor
Publication Date: 2025.10.01 HAMILTON SUNDSTRAND CORP
  • EP3508304B1 patent drawingFigure 1A
  • EP3508304B1 patent drawingFigure 1B
  • EP3508304B1 patent drawingFigure 1C

AI summary

A hybrid additive manufacturing process is utilized for creating a shrouded rotor with the shrouded rotor (10) having a hub (12) at a radial center, a shroud (16) at a radial outer side, and vanes (14) extending therebetween. The hybrid additive manufacturing process includes forming the shrouded rotor in stages (52, 54, 56), with a first stage being formed by depositing material in an axial direction through a first stage of the hub, machining an outer surface of the first stage of the hub to smooth the outer surface, depositing material on the first stage of the hub in a radial direction through a first stage of the vanes and the shroud, and machining all surfaces of the first stage of the vanes and an inner surface of the first stage of the shroud to smooth the surfaces. Subsequent stages of the shrouded rotor are formed similarly to the first stage.