Linear Actuator with Stationary Magnets and Coils
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Solution Overview
Problem
Mechanical actuators face issues with wear and inefficiency due to moving parts, particularly in small-scale applications like Micro Air Vehicles, where traditional actuators are unwieldy and unreliable.
Innovation Solution
A linear actuator system utilizing stationary vertical magnets and coils with a slug that moves under reluctance force, minimizing moving parts and optimizing power efficiency by controlling magnetic fields and coil excitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional mechanical actuators are used, then actuation function is achieved, but wear and inefficiency occur due to moving parts
Solution Approach 1:
The patent replaces traditional mechanical actuators with a magnetic actuation system using permanent magnets and coils. The magnetic field interacts with a ferromagnetic slug to produce linear motion, eliminating mechanical linkages, pivots, and springs. This substitution of magnetic fields for mechanical forces directly resolves the contradiction by maintaining actuation functionality while removing moving parts that cause wear and reduce reliability.
Solution Approach 2:
The invention extracts and eliminates the moving parts from the actuator system. By using a stationary permanent magnet and stationary coils that interact with a ferromagnetic slug through magnetic fields, the design removes all mechanical moving components such as linkages, pivots, and springs. This extraction of problematic moving parts directly improves reliability while maintaining the actuation function.
2Volume of moving object
If mechanical actuators are miniaturized for MAVs, then size is reduced, but actuators become unwieldy and unreliable
Solution Approach 1:
The patent applies magnetic actuation principles that are inherently suitable for miniaturization. The interaction between permanent magnets, coils, and a ferromagnetic slug creates a compact actuation mechanism without mechanical linkages. This magnetic system can be scaled down to MAV sizes while maintaining reliability because it eliminates the wear-prone mechanical components that become problematic at small scales.
Solution Approach 2:
The invention uses a ferromagnetic slug as the moving element, leveraging the properties of ferromagnetic materials to respond to magnetic fields. This material choice enables compact, reliable actuation at small scales by using materials with high magnetic permeability and saturation, allowing the actuator to be miniaturized for MAV applications while maintaining sufficient force output and reliability.
3Force
If coils are energized to generate magnetic force, then actuation is achieved, but electrical power is dissipated
Solution Approach 1:
The patent employs periodic excitation of the coils to generate the required magnetic force for actuation. By energizing the coils in a periodic manner synchronized with the desired motion profile, the system achieves the necessary force while minimizing continuous power dissipation. This periodic action allows the permanent magnets to maintain the magnetic field while coils provide pulsed excitation only when needed for force generation.
Solution Approach 2:
The invention optimizes the electrical parameters of the coil system to minimize power dissipation. By carefully selecting coil resistance, inductance, and excitation timing, and by controlling the current waveform to match the mechanical requirements, the system achieves the necessary magnetic force while minimizing I²R losses. The permanent magnets provide a static field that requires no power, and the coils provide only the dynamic component needed for actuation.
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 solution provides a reliable and efficient actuation mechanism with reduced wear, achieving tailored acceleration profiles and minimized electrical power dissipation, suitable for small-scale applications like Micro Air Vehicles.
Implementation Method 1
A top coil is positioned within the top magnet. A bottom coil is positioned within the bottom magnet. energizing at least one coil generating a force that causes the slug to slide along an axis of the coils
Implementation Method 2
A slug is slidably positioned within the top coil and bottom coil. energizing at least one coil generating a force that causes the slug to slide along an axis of the coils
Data Source
AI summary
A linear actuating device contains a top magnet and a bottom magnet. The bottom magnet is axially aligned with the top magnet. The top magnet and the bottom magnet have opposing magnetization. A washer is sandwiched between the top magnet and the bottom magnet. A top coil is positioned within the top magnet. A bottom coil is positioned within the bottom magnet. A slug is slidably positioned within the top coil and bottom coil. An actuating member is integral with the slug.