Unidirectional thrust air cycle machine arrangement with asymmetric thrust bearings

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Solution Overview

Problem

Existing air cycle machines (ACMs) face challenges in efficiently supporting axial loads that switch directions, leading to high-friction rubbing and requiring a more compact design that can handle unidirectional and bidirectional thrust loads.

Innovation Solution

The ACM incorporates a single robust thrust bearing for unidirectional loading, combined with journal bearings for radial support, and an axisymmetric thrust bearing for secondary axial load support, ensuring adequate support in all load conditions while maintaining a compact design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional bearing arrangements are used to support axial loads that switch directions, then the ACM can handle bidirectional thrust loads, but high-friction rubbing occurs and the design becomes less compact

Engineering Contradiction:

Improveability to handle bidirectional thrust loadsVSAvoidhigh-friction rubbing

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The bearing system is segmented into multiple specialized bearings: a first thrust bearing for primary axial load support in one direction, a second thrust bearing for axial load support in the opposite direction, and a third bearing for radial support. This segmentation allows each bearing to be optimized for its specific function, eliminating high-friction rubbing by ensuring proper clearance and load distribution across all bearings.

Inventive Principle:

Principle #1Segmentation

2Reliability

If multiple bearings are used to support all load conditions, then adequate support is provided in all load conditions, but the ACM assembly becomes less compact

Engineering Contradiction:

Improveadequate support in all load conditionsVSAvoidACM assembly size

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

Multiple bearing functions are merged into a single integrated bearing support structure. The first, second, and third bearings are all supported by a common bearing support element that is received within the rotor hub pocket, consolidating what would otherwise be separate mounting structures into one compact assembly.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The bearing support element is nested within the rotor hub pocket, and the multiple bearings are nested within the bearing support element. This nested arrangement maximizes space utilization and creates a compact overall assembly while maintaining all necessary bearing functions.

Inventive Principle:

Principle #7Nested doll (Nesting)

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 provides sufficient support for rotating components in all load conditions, resulting in a more compact ACM assembly compared to traditional arrangements.

Implementation Method 1

The rotor defines a pocket having an open end and forms a foil bearing shaft. The ACM further includes an inlet housing partially surrounding the rotor, an outlet housing including a forward face and a bearing support element extending from the forward face and being receivable in the pocket via the open end, one or more first bearings disposed within the bearing support element to support rotation of the foil bearing shaft

Methodology Applied

Scientific EffectHydrodynamic lubrication: Lubrication

Implementation Method 2

a second bearing interposed between the forward face of the outlet housing and the rear face of the rotor and a third bearing interposed between the forward face of the rotor and the inlet housing

Methodology Applied

Scientific EffectContact force: Force

Data Source

PatentUS20250347448A1Unidirectional thrust air cycle machine arrangement with asymmetric thrust bearings

Publication Date: 2025.11.13 HAMILTON SUNDSTRAND CORP

AI summary

An air cycle machine (ACM) is provided and includes a rotor including rear and forward faces and a central portion interposed between the rear and forward faces with outwardly extending blades. The rotor defines a pocket having an open end and forms a foil bearing shaft. The ACM further includes an inlet housing partially surrounding the rotor, an outlet housing including a forward face and a bearing support element extending from the forward face and being receivable in the pocket via the open end, one or more first bearings disposed within the bearing support element to support rotation of the foil bearing shaft, a second bearing interposed between the forward face of the outlet housing and the rear face of the rotor and a third bearing interposed between the forward face of the rotor and the inlet housing.