Wear Ring Tab Design for Integrated Drive Generator Speed Control

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Solution Overview

Problem

Integrated drive generators face challenges in maintaining a constant frequency of generated electric power due to varying input shaft speeds, which requires effective speed trimming mechanisms to stabilize the output speed and frequency.

Innovation Solution

A wear ring design is implemented in the speed trimming unit, featuring a cylindrical body with a radially extending tab that prevents rotation, ensuring precise control of speed and direction through interaction with the swash plate and hydraulic units, thereby stabilizing the output speed and frequency of the generator.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a wear ring is designed to prevent rotation in the speed trimming unit, then the control precision of speed and direction is improved, but the device complexity increases due to the additional tab structure and its interaction components

Engineering Contradiction:
Improvespeed control precisionVSAvoidwear ring structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The wear ring is segmented into a cylindrical body and a radially extending tab portion. This segmentation allows the tab to interact with the swash plate for rotational prevention while the cylindrical body maintains the hydraulic connection, thereby achieving precise speed control without overly complicating the overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tab on the wear ring acts as an intermediary element between the hydraulic unit and the swash plate. It transmits the rotational constraint from the swash plate to the cylindrical body, enabling precise speed and direction control while maintaining a relatively simple wear ring design.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the wear ring includes a radially extending tab to prevent rotation, then the stability of output speed and frequency is improved, but the manufacturing complexity increases due to the additional radial tab feature

Engineering Contradiction:
Improveoutput speed stabilityVSAvoidwear ring manufacturing ease
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The wear ring is segmented into a cylindrical body and a radially extending tab portion. This segmentation allows the tab to interact with the swash plate for rotational prevention while the cylindrical body maintains the hydraulic connection, thereby achieving precise speed control without overly complicating the overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The radially extending tab provides localized rotational constraint at the interface with the swash plate, while the rest of the cylindrical body maintains its simple hydraulic connection function. This local quality approach stabilizes output speed without requiring complex features throughout the entire wear ring structure.

Inventive Principle:
Principle #3Local quality

3Productivity

If the wear ring design incorporates interaction with swash plate and hydraulic units for precise control, then the efficiency of speed trimming mechanism is improved, but the device complexity increases

Engineering Contradiction:
Improvespeed trimming efficiencyVSAvoidtrimming unit complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The wear ring serves multiple functions: it maintains hydraulic connection through its cylindrical body and prevents rotation through its radially extending tab. This multi-functionality improves speed trimming efficiency without requiring separate components for each function, thereby limiting the increase in device complexity.

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

Solution Approach 2:

The wear ring combines the hydraulic connection function (cylindrical body) and the rotational prevention function (radially extending tab) into a single integrated component. This merging improves the efficiency of the speed trimming mechanism by ensuring coordinated action between hydraulic control and rotational constraint while avoiding the complexity of multiple separate parts.

Inventive Principle:
Principle #5Merging (Combining)

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 wear ring design effectively stabilizes the output speed and frequency of the generator by preventing rotation and ensuring precise control, enhancing the efficiency of the speed trimming mechanism and maintaining consistent electric power generation.

Implementation Method 1

A wear ring that is incorporated into the trimming unit faces design challenges

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3489532B1Wear ring for integrated drive generator
Publication Date: 2022.12.28 HAMILTON SUNDSTRAND CORP
  • EP3489532B1 patent drawingFigure 1
  • EP3489532B1 patent drawingFigure 2~3
  • EP3489532B1 patent drawingFigure 4A~4B

AI summary

A wear ring for use in an integrated drive generator has a cylindrical body defining an axis and having a tab (150) extending radially outwardly of an outer cylindrical surface of the cylindrical body. The tab has a radially outer point (151). A ratio of a first radius to the outer cylindrical surface from the axis to a second radius extending to the radially outer point from the axis is between .90 and .95. An integrated drive generator and a method are also disclosed.