Integrated Low-Profile Electro-Hydrostatic Actuator Layout

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Solution Overview

Problem

Current electro-hydrostatic actuator systems for aircraft are bulky, heavy, and costly due to their component-based design, requiring assembly and plumbing, which limits their durability and efficiency in hydraulic operations.

Innovation Solution

A low-profile electro-hydrostatic actuator is developed with an integrated design that includes a piston assembly, hydraulic cylinder, reservoir, electric motor, and bi-directional pump system, featuring a thermal management layer and a flow control network to manage hydraulic fluid flow efficiently, eliminating the need for separate components and enhancing durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a component-based EHA system is used, then the actuator can perform hydraulic operations, but the system becomes bulky in size and heavy in weight

Engineering Contradiction:
Improvehydraulic operation capabilityVSAvoidactuator weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent integrates the electric motor, hydraulic pump, reservoir, and control valves into a single compact housing, eliminating the need for separate component mounting and plumbing. This merging of components directly reduces the overall weight and footprint of the actuator system while maintaining full hydraulic operation capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated design allows a single housing to perform multiple functions: the electric motor drives the hydraulic pump, the housing serves as both structural support and fluid containment, and integrated valves provide flow control. This multi-functionality reduces the number of separate components needed, thereby reducing overall system weight.

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

2Reliability

If a component-based EHA system is used, then the actuator can perform hydraulic operations, but the manufacturing cost increases

Engineering Contradiction:
Improvehydraulic operation capabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By combining multiple components into a single integrated housing, the patent reduces the number of manufacturing steps, assembly operations, and quality inspections required. This consolidation simplifies the manufacturing process and reduces overall production costs while maintaining hydraulic operation capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated housing is designed as a single manufacturable unit that can be produced using modern manufacturing techniques such as injection molding or metal forming. This segmentation approach allows for efficient mass production and reduces per-unit manufacturing costs compared to assembling multiple separate components.

Inventive Principle:
Principle #1Segmentation

3Reliability

If a component-based EHA system is used, then the actuator can perform hydraulic operations, but assembly and plumbing complexity increases

Engineering Contradiction:
Improvehydraulic operation capabilityVSAvoidassembly and plumbing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates all hydraulic components including the pump, reservoir, and control valves within a single housing, eliminating the need for external plumbing and complex assembly procedures. This integration dramatically simplifies installation and reduces assembly complexity while maintaining full hydraulic functionality.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If traditional EHA design is used, then the actuator can operate hydraulically, but the profile size is large

Engineering Contradiction:
Improvehydraulic operation capabilityVSAvoidactuator profile
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent employs a nested arrangement where the hydraulic pump, reservoir, and control valves are positioned within or around each other in a compact configuration. This nesting approach minimizes the overall profile and footprint of the actuator while maintaining all necessary hydraulic functions.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The integrated design optimizes component arrangement in three-dimensional space, utilizing vertical stacking and radial positioning to reduce the horizontal footprint. By reorganizing components along different spatial dimensions, the patent achieves a compact profile without compromising hydraulic operation capability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 integrated design reduces weight and cost while improving durability and efficiency by self-containing all necessary components, enabling prolonged hydraulic operation and effective thermal management, thus addressing the limitations of existing systems.

Implementation Method 1

an electric motor located adjacent to and operatively coupled to the hydraulic pump system for driving the hydraulic pump system

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a hydraulic pump system for moving hydraulic fluid in the reservoir and the hydraulic fluid chamber region

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 3

featuring a thermal management layer

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

effective thermal management

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3450773B1Low profile electro-hydrostatic actuator
Publication Date: 2023.03.29 THE BOEING CO
  • EP3450773B1 patent drawingFigure 1
  • EP3450773B1 patent drawingFigure 2
  • EP3450773B1 patent drawingFigure 3

AI summary

In general, certain examples of the present disclosure provide an electro-hydrostatic actuator comprising a piston assembly (20) and a hydraulic cylinder (30,210). The piston assembly, having a piston head (26) and a piston rod (22) extending from the piston head, is located and movable within the hydraulic cylinder. The hydraulic cylinder includes a hydraulic fluid chamber region (28) including a piston side chamber (32) and a rod side chamber (34), a reservoir (36) for storing hydraulic fluid located within the hydraulic cylinder which is in fluid communication with the hydraulic fluid chamber region. The electro-hydrostatic actuator includes a hydraulic pump system (40) for moving hydraulic fluid in the reservoir and the hydraulic fluid chamber region, the hydraulic pump system in fluid communication with a flow control network (38) in a hydraulic cylinder boss (211) for controlling a direction and flow magnitude of hydraulic fluid within the hydraulic fluid chamber region, and an electric motor (50) for driving the hydraulic pump system.