EMA Damping Arrangement Using Lubricant Flow Restriction
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Solution Overview
Problem
Electromechanical actuators (EMAs) face issues with rapid and uncontrolled movement during power loss, leading to potential damage due to collisions with end stops and other components.
Innovation Solution
A damping arrangement using lubricant fluid and pistons with constrained passages to provide a damping force, reducing the velocity of the actuator member upon power loss, thereby protecting the EMA components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the actuator member moves rapidly during power loss, then the actuator member can return to the retracted position quickly, but the actuator member will collide with the end stop and cause damage
Solution Approach 1:
The patent incorporates a damping arrangement with constrained passages and lubricant fluid that activates beforehand to cushion the actuator member's movement. When the actuator member moves toward the retracted position, the lubricant fluid is forced through the constrained passages, creating viscous resistance that dissipates kinetic energy and prevents collision damage to the end stop.
Solution Approach 2:
The damping arrangement acts as an intermediary between the actuator member and the end stop. The lubricant fluid flowing through the constrained passages provides a mediating damping force that controls the actuator member's velocity, transforming the harmful direct collision into a controlled deceleration process.
2Object-affected harmful factors
If a damping arrangement is added to prevent collision damage, then the protection against damage is improved, but the device complexity increases
Solution Approach 1:
The damping arrangement is designed to perform multiple functions: it provides damping force during normal operation to control actuator member velocity, and it activates during failure events to prevent collision damage. The same lubricant fluid that reduces friction during normal operation is also used to provide damping forces during failure events, eliminating the need for separate damping systems.
Solution Approach 2:
The damping arrangement utilizes the existing lubricant fluid already present in the electromechanical actuator. The lubricant fluid automatically provides damping forces when the actuator member moves rapidly during power loss, without requiring external control systems or additional power sources. The constrained passages and piston structure passively convert the lubricant fluid's viscous properties into protective damping forces.
3Reliability
If the piston is biased towards the neutral position, then the piston can be repeatedly used to provide damping force, but the biasing member adds device complexity
Solution Approach 1:
The biasing member applies a counteracting force to the piston, biasing it toward the neutral position. This counterforce ensures that after the actuator member collides and compresses the lubricant fluid through the constrained passages, the piston automatically returns to its neutral position, ready to provide damping force again. This mechanism enables the damping system to be reused repeatedly without manual intervention.
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 damping arrangement effectively reduces the momentum of the actuator member upon collision, preventing damage and allowing safe, controlled retraction, with the ability to be reused multiple times.
Implementation Method 1
The damping arrangement uses a lubricant fluid and a piston with a constrained passage to provide a damping force, reducing the velocity of the actuator member upon power loss
Data Source
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AI summary
A damping arrangement for an electro-mechanical actuator comprising an actuator member (9) and a lubricant fluid (11) for lubricating the actuator member (9) during movement of the actuator member (9). The damping arrangement comprises a constrained passage (15), the constrained passage (15) configured to restrict a flow of the lubricant fluid (11) in order to provide a damping force to resist a movement of the actuator member (9) during a failure event