Thrust Reverser Electric Motor Control for Overheating

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Electric motors actuating movable hoods in thrust reversers for turbojets are prone to overheating due to blockages, which can lead to damage and require frequent maintenance, especially during high-stress landing scenarios where precise timing is critical for safe operation.

Innovation Solution

A method that monitors the electric motor's state, disconnects power if it fails to operate, and alternates between operation and rest periods to prevent overheating, with predefined or temperature-based rest periods, and adjusts power delivery based on turbojet pressure and stress levels to manage blockages effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of stationary object

If an electric motor is used to actuate the movable hood, then the weight and bulk are reduced compared to hydraulic or pneumatic systems, but the motor is prone to overheating and damage when blocked

Engineering Contradiction:

Improveweight of actuator systemVSAvoidmotor reliability under blockage

Core Design Contradiction:

Weight of stationary objectVSReliability

Solution Approach 1:

The control method implements periodic action by alternating between operation phases and rest phases. When the motor is blocked, it is disconnected from power for a predetermined rest period to cool down, then reconnected to attempt operation again. This periodic on-off cycling prevents continuous overheating while maintaining the ability to overcome temporary blockages, resolving the contradiction between using a lightweight electric motor and ensuring its reliability under blockage conditions.

Inventive Principle:

Principle #19Periodic action

2Productivity

If the electric motor operates continuously to overcome blockages, then the movable hood can be actuated, but the motor temperature increases and damages power electronics

Engineering Contradiction:

Improveactuation speedVSAvoidmotor temperature

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The control method applies periodic action by implementing rest phases between operation phases. When blockage is detected, the motor is disconnected for a predetermined rest period allowing temperature reduction, then reconnected to continue actuation. This periodic cycling maintains productivity by eventually overcoming blockages while preventing continuous temperature rise that would damage power electronics.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The control method uses feedback by continuously monitoring motor operation status and blockage conditions. Based on this feedback, the system dynamically adjusts the operation-rest cycle timing and power delivery to balance actuation requirements with thermal protection, preventing temperature-related damage while maintaining actuation capability.

Inventive Principle:

Principle #23Feedback

3Reliability

If the motor is disconnected for rest periods to cool down, then overheating is prevented, but the time to actuate the movable hood increases

Engineering Contradiction:

Improvemotor thermal protectionVSAvoidactuation time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The control method applies partial action by implementing rest phases of predetermined duration that are optimized to provide sufficient cooling without excessive delay. The rest period is long enough to prevent thermal damage but short enough to minimize actuation time loss. The system accepts that some time loss is necessary to protect the motor, rather than attempting to eliminate all delays through continuous operation.

Inventive Principle:

Principle #16Partial or excessive action

4Reliability

If hydraulic or pneumatic cylinders are used to actuate the movable hood, then the system is robust, but the space required and maintenance requirements increase

Engineering Contradiction:

Improvesystem robustnessVSAvoidcircuit complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The control method replaces complex hydraulic or pneumatic actuation systems with a simplified electric motor-driven system. The electric motor directly actuates the movable hood without requiring separate hydraulic or pneumatic circuits, reducing device complexity while maintaining robustness through the motor's inherent reliability and the simplicity of electrical connections compared to fluid-based systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS9062627B2Method for controlling electric motors of a thrust reverser

Publication Date: 2015.06.23 SAFRAN NACELLES

AI summary

The invention relates to a method for controlling an electric motor actuating a mobile hood provided in a thrust reverser for a turboreactor, said method being characterized in that it comprises steps of: determining the operating state of the electric motor; interrupting the supply of the electric motor if said motor is not in operation during a defined period of time; reactivating the electric motor after an idle period and repeating the previous steps or definitively stopping the motor if the steps have already been repeated a pre-defined number of times. The invention also relates to a method for managing the electrical supply of a motor provided in a device arranged in the vicinity of a turboreactor.