Vented Electromechanical Actuator Pressure Equalization
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Solution Overview
Problem
Traditional electric motor actuators in aircraft and large vehicle brake systems face moisture ingress due to pressure changes, leading to operational life and performance degradation.
Innovation Solution
A vented electric motor actuator (EMA) with a gas permeable-liquid impermeable membrane and an air flow path, which allows gas exchange while preventing liquid ingress, and a desiccant material to manage water vapor, coupled with a ball screw assembly that adjusts its volume to control air flow through orifice channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the actuator housing is sealed to prevent moisture ingress, then reliability is improved, but pressure changes during operation cause moisture to be drawn into the actuator through seal imperfections
Solution Approach 1:
The patent employs a porous desiccant material (such as molecular sieve or activated alumina) that allows water vapor to pass through while blocking liquid water. The desiccant is positioned in the vent pathway, creating a selective barrier that permits pressure equalization through vapor diffusion while preventing harmful liquid moisture ingress into the actuator housing.
Solution Approach 2:
The vent assembly acts as an intermediary element between the internal actuator environment and external atmosphere. It mediates pressure equalization while filtering out harmful moisture through the combination of vent pathway and desiccant material, allowing gas exchange without direct liquid contact.
2Object-affected harmful factors
If the ball screw assembly is extended to increase free air volume, then pressure equalization is enhanced, but the actuator operational cycle time increases
Solution Approach 1:
The desiccant material provides passive, continuous moisture absorption capability without requiring active control or additional energy input. The vent assembly automatically equalizes pressure through the desiccant pathway whenever pressure differential exists, eliminating the need for active pressure management systems that would increase cycle time.
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 vented EMA effectively manages pressure changes and prevents moisture ingress, enhancing operational reliability and performance by equalizing internal and external pressures while maintaining the actuator's integrity.
Implementation Method 1
a vent having a gas exchange apparatus including a gas permeable-liquid impermeable membrane whereby gas may be drawn into the vented EMA and whereby liquid may be prevented from being drawn into the vented EMA
Implementation Method 2
absorbing, by a desiccant material, the first quantity of water vapor
Implementation Method 3
evaporating, from the desiccant material, a second quantity of water vapor
Data Source
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AI summary
A vented EMA (2) may have a vent (14) that allows gas to pass from into and out of the vented EMA (2), while preventing liquid from passing into and out of the vented EMA (2). The vented EMA (2) may have a desiccant material (26) inside the vented EMA (2) that absorbs condensation from within the vented EMA (2). A vented EMA (2) may also have an air flow path (18) that conducts gas into and out of the vent (14) during operation. As a result, the pressure inside the vented EMA (2) may equalize with the pressure outside the vented EMA (2), but the deleterious ingress of liquids may be ameliorated.