Variable Diffuser for Cabin Air Compressor

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Solution Overview

Problem

Traditional aircraft environmental control systems face inefficiencies in controlling cabin air pressure, particularly in more electric aircraft, where variable speed compressors struggle to optimize airflow between maximum and minimum flow positions effectively.

Innovation Solution

A variable diffuser system for a rotating machine, featuring a drive ring and diffuser vanes that pivot between maximum and minimum flow positions, utilizing a compact diffuser actuator with a linkage mechanism to achieve mechanical advantage and efficient airflow control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a variable speed compressor is used to control cabin air pressure, then the system can adapt to different operating conditions, but the ability to optimize airflow between maximum and minimum flow positions deteriorates

Engineering Contradiction:
Improveadaptability to different operating conditionsVSAvoidairflow optimization capability
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The diffuser vanes are made dynamically adjustable through a drive ring mechanism that can pivot the vanes between maximum and minimum flow positions. This dynamic adjustment allows the system to optimize airflow characteristics while adapting to different operating conditions, resolving the contradiction between adaptability and productivity.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If a variable diffuser with pivoting diffuser vanes is implemented, then airflow control is improved, but the device complexity increases

Engineering Contradiction:
Improveairflow control capabilityVSAvoiddiffuser mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

Multiple diffuser vanes are merged into a unified structure where they are collectively pivoted by a single drive ring. This combining approach allows airflow control to be achieved while reducing the number of independent actuators needed, thereby managing device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The drive ring serves multiple functions: it pivots all diffuser vanes simultaneously, provides mechanical advantage through its rotational motion, and enables both maximum and minimum flow positions. This multi-functionality reduces the need for separate mechanisms for each function, managing overall system complexity.

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

3Weight of moving object

If a compact diffuser actuator with linkage mechanism is used, then the system weight is reduced, but the mechanical advantage for actuation decreases

Engineering Contradiction:
Improvediffuser actuator weightVSAvoidmechanical advantage for actuation
Core Design Contradiction:
Weight of moving objectVSForce

Solution Approach 1:

The drive ring utilizes rotational motion along a curved path to generate mechanical advantage. The circular geometry of the drive ring allows it to convert rotational movement into effective pivoting force on the diffuser vanes, providing sufficient mechanical advantage while maintaining a compact, lightweight actuator design.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 solution enables efficient control of airflow in cabin air compressors, allowing for a lightweight and compact system that optimizes airflow between extreme positions, reducing the power requirements for diffuser actuation and enhancing overall system performance.

Implementation Method 1

utilizing a compact diffuser actuator with a linkage mechanism to achieve mechanical advantage and efficient airflow control

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP2412984B1Variable diffuser for a cabin air compressor
Publication Date: 2020.04.15 HAMILTON SUNDSTRAND CORP
  • EP2412984B1 patent drawingFigure 1~2
  • EP2412984B1 patent drawingFigure 3~4
  • EP2412984B1 patent drawingFigure 5

AI summary

A variable diffuser (26) for a rotating machine (20) includes a multiple of diffuser vanes (34) mounted to a drive ring (36). The multiple of diffuser vanes (34) are movable in unison between a maximum flow position and a minimum flow position in response to rotation of a crank (44) to rotate the drive ring (36) about a centerline through a link arm (46).