Linear Vibration Actuator Magnet Layout for Stable Driving Force
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vibration generating devices experience a reduction in driving force due to changes in the intensity of the magnetic field passing through the coil, which affects the efficiency of linear vibration actuators.
Innovation Solution
A vibration generating device is designed with a magnetic flux source comprising a left-hand magnet, at least one middle magnet, and a right-hand magnet, and a coil with specific wire bundles to cross the magnetic fluxes generated by these magnets, ensuring that the magnetic fluxes passing through the coil are uniformly distributed to minimize changes in the magnetic field intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the movable body moves in a back-and-forth direction, then the magnetic field intensity passing through the coil changes, but the driving force (Lorentz force) decreases
Solution Approach 1:
The patent applies local quality by creating different magnetic flux densities in different regions. Specifically, the magnetic flux density in the space between the right-hand wire bundle of the left-hand coil and the middle magnet is made less than the magnetic flux density in the space between the left-hand wire bundle of the left-hand coil and the left-hand magnet. This non-uniform distribution compensates for the induced current effects and maintains consistent driving force throughout the movable body's reciprocating motion.
2Power
If magnets are arranged to generate magnetic flux, then electromagnetic driving force is produced, but induced current reduces the effective driving force
Solution Approach 1:
The patent converts the harmful induced current effect into a beneficial design criterion by deliberately creating asymmetric magnetic flux distribution. The induced current, which normally opposes the driving force, is compensated for by designing the magnetic flux source to produce higher flux density in regions where induced current would otherwise cause greater force reduction. This transforms the energy loss mechanism into a design parameter for optimization.
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 proposed solution effectively suppresses the reduction in driving force, maintaining a consistent electromagnetic force across the coil, thereby enhancing the efficiency and reliability of the vibration generating device.
Implementation Method 1
a magnetic flux source that is fixed to one of the movable body and the stationary body and configured to generate a magnetic flux along an up-and-down direction; and a coil that is fixed to the other of the movable body and the stationary body so as to cross the magnetic flux generated by the magnetic flux source
Implementation Method 2
an induced current occurs in a direction to reduce the change in the intensity of the magnetic field, and a driving force (Lorentz force) to move the movable body may decrease
Data Source
AI summary
A vibration generating device includes a coil and a magnetic flux source. The magnetic flux source includes a left-hand magnet, a first middle magnet, a second middle magnet, and a right-hand magnet. The coil includes a left-hand coil and a right-hand coil. The left-hand coil and the right-hand coil each include a left-hand wire bundle and a right-hand wire bundle. Magnetic fluxes from the middle magnet passing through, in an up-and-down direction, a space between the right-hand wire bundle of the left-hand coil and the first middle magnet are less than magnetic fluxes from the left-hand magnet that pass through, in the up-and-down direction, a space between the left-hand wire bundle of the left-hand coil and the left-hand magnet.