Electromagnetic Actuator Tapered Surfaces Magnetic Force
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electromagnetic actuators experience a decrease in magnetic attracting force as the plunger moves closer to the stator, leading to a deterioration in plunger-driving force due to the parabolic characteristic of magnetic efficiency.
Innovation Solution
The electromagnetic actuator is designed with a coil, plunger, and stator, where at least one portion is configured with two tapered surfaces that decline in the same direction as the axial direction of the plunger, enhancing magnetic efficiency by maintaining a constant high magnetic attracting force after initial overlap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the plunger is designed with ring-shaped projections and the stator with a ring-shaped projection to generate magnetic attracting force at multiple portions, then magnetic efficiency is enhanced at the start of driving, but the magnetic attracting force significantly decreases after the plunger and stator overlap
Solution Approach 1:
The invention changes the geometric parameters of the magnetic path by introducing tapered surfaces. The plunger has an inner tapered surface and the stator has an outer tapered surface, creating a gradually varying magnetic path width instead of a fixed width. This parameter change allows the magnetic attracting force to be maintained at a high level throughout the stroke by compensating for the increasing magnetic path width as the plunger moves forward.
2Length of moving object
If the plunger stroke is increased to improve driving capability, then the actuator can cover a larger range, but the magnetic attracting force deteriorates due to the parabolic characteristic
Solution Approach 1:
The tapered surfaces create a continuously varying magnetic path width parameter that increases gradually with plunger displacement. This compensates for the parabolic decay of magnetic force, allowing the actuator to maintain high driving force throughout a longer stroke range.
3Device complexity
If conventional parallel surfaces are used between plunger and stator, then the structure is simple, but the magnetic attracting force decreases as the plunger comes closer to the stator
Solution Approach 1:
The invention replaces the conventional parallel (flat) surfaces with tapered surfaces that have a gradual curvature. The plunger has an inner tapered surface and the stator has an outer tapered surface, creating a conical magnetic path geometry instead of a cylindrical one. This curved geometry maintains a more uniform magnetic flux distribution and prevents the significant force decrease that occurs with parallel surfaces.
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 configuration maintains a high and constant magnetic attracting force after the plunger overlaps with the stator, improving driving efficiency and allowing for a smaller actuator size while preventing a decline in driving force with increased stroke.
Implementation Method 1
an electromagnetic actuator (linear solenoid) which drives the spool
Implementation Method 2
a magnetic attracting force is generated at multiple portions thereof
Data Source
AI summary
A stator is provided with a ring-shaped outer stator-projection and a ring-shaped inner stator-projection. A plunger is provided with a ring-shaped outer plunger-projection and a ring-shaped inner plunger-projection. A magnetic force is generated at three portions between the plunger and the stator. The inner stator-projection has a first tapered surface and the outer plunger-projection has a second tapered surface. The first tapered surface and the second tapered surface confront each other when the plunger moves toward the stator.