Electromechanical Actuator Low-Temperature Heating Control

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Solution Overview

Problem

Electromechanical actuators in aircraft face performance degradation due to high lubricant viscosity at extremely low temperatures, leading to increased friction losses, which existing solutions attempt to mitigate by periodic movement during non-use.

Innovation Solution

An electromechanical actuator control system that receives temperature signals and generates a current signal to the electric motor to produce heat without significant torque, using methods such as high-frequency currents or power signals in phase with permanent magnets to maintain a minimum actuator temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the electromechanical actuator is left stationary during long cruise segments, then energy consumption is reduced, but the lubricant viscosity increases due to low temperatures causing performance degradation

Engineering Contradiction:
Improveenergy consumptionVSAvoidactuator performance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent replaces the conventional mechanical periodic movement method with an electromagnetic heating method. Instead of mechanically moving the actuator to generate heat through friction, the system uses electrical current applied to the motor windings to generate heat directly, thereby maintaining lubricant temperature and performance without the energy cost of mechanical movement.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system changes the temperature parameter of the actuator by applying controlled electrical heating. The control system monitors temperature and adjusts the heating current to maintain the lubricant within an optimal temperature range, preventing viscosity increase while minimizing energy consumption.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If periodic movement is applied to the actuator during non-use, then lubricant viscosity is reduced through friction heating, but energy is wasted and wear increases

Engineering Contradiction:
Improvelubricant performanceVSAvoidenergy waste
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent substitutes electromagnetic heating for mechanical movement. The heating element converts electrical energy directly into thermal energy, bypassing the need for mechanical motion that would otherwise be required to generate friction heat. This eliminates the associated energy waste and mechanical wear.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system converts electrical energy, which would otherwise be wasted during idle periods, into beneficial thermal energy. The control system utilizes available electrical power to heat the actuator, transforming what would be a wasted resource into a means of maintaining lubricant performance.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Temperature

If high current is applied to heat the motor, then actuator temperature is maintained, but significant torque is also generated causing unwanted movement

Engineering Contradiction:
Improveactuator temperatureVSAvoidtorque
Core Design Contradiction:
TemperatureVSForce

Solution Approach 1:

The control system dynamically adjusts the heating current based on real-time temperature feedback. By continuously monitoring the actuator temperature and modulating the current accordingly, the system maintains temperature without applying excessive current that would generate unwanted torque and movement.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system employs a feedback control mechanism where temperature sensors monitor the actuator temperature and feed this information back to the control system. The controller adjusts the heating current based on the temperature deviation from the setpoint, ensuring precise temperature maintenance while preventing overheating and unwanted torque generation.

Inventive Principle:
Principle #23Feedback

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

Effectively prevents lubricant viscosity from becoming too high at low temperatures, ensuring smooth operation and maintaining performance by continuously heating the actuator when temperatures drop below a threshold.

Implementation Method 1

The control is operable to produce a current signal sent to the electric motor which will generate heat without significant torque

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2343619B1Minimum temperature control for electromechanical actuator
Publication Date: 2017.09.06 HAMILTON SUNDSTRAND CORP
  • EP2343619B1 patent drawingFigure 1~2
  • EP2343619B1 patent drawingFigure 3

AI summary

A component (22) intended for use in very low temperature situations has an electromechanical actuator (24) with a control (28) for an electric motor (23). The control receives a temperature signal (30) indicative of a temperature being experienced by the electromechanical actuator. The control is operable to produce a current signal sent to the electric motor which will generate heat without significant torque. A method of operating the electromechanical actuator is also disclosed.