Electromagnetic Actuator Structure for Dual Stable End Positions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electromagnetic actuators struggle to maintain stability in both end positions without excitation and achieve high holding forces efficiently, often compromising on manufacturing complexity and cost.
Innovation Solution
The electromagnetic actuator features a housing with ferromagnetic pole shoes, a movable structure with a magnet system, and an annular coil that forms an air gap system with axially variable gaps, allowing secure positioning in both end positions without coil excitation and rapid switching with coil energization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If permanent magnets are arranged to stabilize the armature in one switching position without energization, then holding force is improved in that position, but the armature cannot be stabilized in both end positions without excitation
Solution Approach 1:
The magnet system is segmented into multiple permanent magnets arranged in specific patterns on opposite pole shoes. Each magnet arrangement contributes to stabilizing the armature in a specific end position, enabling dual-position stability without continuous energization.
Solution Approach 2:
The permanent magnets are arranged asymmetrically with respect to the air gap, creating different magnetic field distributions for each end position. This asymmetric arrangement allows the armature to be stably held in both end positions while maintaining the ability to switch between them.
2Volume of moving object
If the permanent magnet arrangement lies between the two excitation windings, then the structure is compact, but its effectiveness is impaired as a result of leakage flux
Solution Approach 1:
Ferromagnetic pole shoes are introduced as intermediary elements between the permanent magnets and the armature. These pole shoes guide and concentrate the magnetic flux, reducing leakage flux while maintaining the compact arrangement of magnets within the air gap region.
Solution Approach 2:
The magnetic flux distribution is optimized locally by positioning permanent magnets at specific locations on the pole shoes and using ferromagnetic materials to concentrate flux where needed. This ensures high magnetic effectiveness in critical regions while maintaining overall compactness.
3Force
If an electromagnetic actuator uses complex magnet arrangements to achieve high holding forces in both positions, then holding force is improved, but manufacturing complexity increases
Solution Approach 1:
Multiple permanent magnets are merged into integrated magnet arrangements on each pole shoe, forming unified magnetic systems that provide holding force in both end positions. This combining approach achieves high holding force while simplifying the number of discrete components and assembly steps.
Solution Approach 2:
The permanent magnet arrangements on the pole shoes serve multiple functions: they generate holding force in both end positions, guide magnetic flux through the air gap, and contribute to the structural integrity of the actuator. This multi-functionality reduces the need for additional specialized components.
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
This design enables secure holding in both end positions without coil excitation, allows for simple and rapid switching, reduces manufacturing costs, and protects the magnetic components from dynamic stress.
Implementation Method 1
the magnet system comprises radially inner and radially outer pole bodies made of a material which conducts the magnetic flux, at least one arrangement of one or more permanent magnets
Implementation Method 2
an annular coil which can be connected to a current source and which, together with the pole shoes, forms an air gap system having axially variable air gaps
Data Source
AI summary
In an electromagnetic actuator having a housing, two ferromagnetic pole shoes are distanced from each other and are rigidly connected to the housing. A mobile structure, which can be moved in the housing along an axis between two end positions, is arranged between the pole shoes, includes at least one magnet system, and is connected to a shaft that is axially displaceable in the housing. The magnet system includes at least one arrangement of at least one permanent magnet polarized radially with respect to the axis, and an annular coil connectable to a current source. The magnet system forms, together with the pole shoes, an air gap system having axially variable air gaps. The mobile structure is securable in each end position without excitation of the coil and is movable from one assumed end position into the opposite end position by excitation of the coil.