Rotor Surface Hardening and Smoothing via Multi-Functional Bodies

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Solution Overview

Problem

Current surface hardening methods for aircraft engine rotors, such as shot peening, increase surface roughness, requiring additional grinding and polishing, which is costly and time-consuming, and do not meet the requirements for high fatigue strength and aerodynamic efficiency.

Innovation Solution

A method involving a container filled with specially designed hardening bodies that perform a vertical and horizontal circular and vibrating movement to simultaneously harden and smooth the rotor surface, using hardening bodies with a circular or elliptical peripheral edge for hardening and flat, curved areas for smoothing, allowing for efficient surface treatment with reduced equipment and time expenditure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If shot peening is used to harden the rotor surface, then fatigue strength is improved, but surface roughness increases significantly

Engineering Contradiction:
Improvefatigue strengthVSAvoidsurface roughness
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent combines two separate processes (surface hardening and surface smoothing) into a single integrated process. The hardening body simultaneously performs both functions: its core structure hardens the surface through impact, while its integrated smoothing elements polish the surface in the same operational step, eliminating the need for separate grinding and polishing operations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hardening body is designed as a multi-functional tool that performs both surface hardening and surface smoothing operations. It incorporates a hardening core for impact hardening and integrated smoothing elements (such as polishing segments or abrasive surfaces) that work simultaneously to reduce surface roughness, making a single component capable of multiple functions.

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

2Strength

If section-by-section shot peening is performed, then surface hardening is achieved, but equipment expenditure and time consumption increase

Engineering Contradiction:
Improvesurface hardnessVSAvoidprocessing efficiency
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent consolidates multiple sequential operations into a single simultaneous process. Instead of performing section-by-section hardening followed by separate smoothing operations, the integrated hardening body treats the entire rotor surface with both hardening and smoothing actions occurring simultaneously, dramatically improving processing efficiency.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hardening body is pre-configured with both hardening and smoothing functionalities integrated into a single tool. This preliminary integration of functions eliminates the need for multiple tool changes, setup adjustments, and sequential operations, allowing immediate simultaneous execution of both processes.

Inventive Principle:
Principle #10Preliminary action

3Strength

If conventional hardening bodies are used, then surface hardening is achieved, but additional grinding and polishing equipment is required

Engineering Contradiction:
Improvesurface strengthVSAvoidequipment requirements
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent integrates the functions of separate hardening and smoothing equipment into a single hardening body. The hardening core provides surface hardening capabilities while integrated smoothing elements (polishing segments, abrasive surfaces, or contour-designed contact areas) provide surface smoothing capabilities, eliminating the need for separate grinding and polishing machines.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hardening body is designed as a universal tool that replaces multiple specialized equipment. It incorporates both hardening functionality (through its core structure and impact mechanism) and smoothing functionality (through integrated polishing elements), making a single component capable of performing tasks that traditionally required separate dedicated machines.

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

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 achieves high fatigue strength and low surface roughness, enabling improved aerodynamic properties and engine efficiency by hardening and smoothing the rotor surface in a single operation with minimal equipment and time, resulting in a surface roughness of less than 0.25 µm [Ra].

Implementation Method 1

To generate the kinetic energy required for hardening and smoothing, the hardening bodies have a mass that is matched to the movement imparted to them

Methodology Applied
Scientific EffectKinetic energy:

Implementation Method 2

the balls strike the surface of the workpiece and cause it to harden

Methodology Applied
Scientific EffectImpact force: Impact Force

Implementation Method 3

circumferential compression hardening area forms a circular section with a small radius

Methodology Applied
Scientific EffectCompression hardening: Compression

Implementation Method 4

the smoothing area forms a spherical section with a radius that is many times larger... for smoothing the surface

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP2251140B1Method for solidifying and polishing the surface of metallic components
Publication Date: 2017.09.20 ROLLS ROYCE DEUT LTD & CO KG
  • EP2251140B1 patent drawingFigure 1

AI summary

The method involves hardening and smoothing the components by a relative movement between a component surfaces and the hardening bodies (10). The work piece surface is hardened and smoothed on the basis of a specific form of the hardening body in a working step. The work piece surface has an edge area or pressure reinforcement area (13) and a smoothing area (14) for smoothing the surface. An independent claim is also included for a hardening body with spherical segments for executing the method.