Linear Vibration Actuator Magnetic Return Without Spring Fatigue

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Solution Overview

Problem

Conventional vibration generating devices face insufficient vibration power at frequencies other than resonance frequencies and have a limited lifespan due to metal fatigue of spring members, while linear vibration actuators with magnetic springs increase part count and size.

Innovation Solution

A vibration generating device that uses a magnetic member to attract a movable magnet back to its initial position without a spring member or additional magnets, utilizing a magnetic flux-generating member and a coil to generate a magnetic force for return motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a spring member is used to return the movable magnet to the initial position, then the device structure is simple, but the vibration power is insufficient at frequencies other than resonance frequencies and the device has limited lifespan due to metal fatigue

Engineering Contradiction:

Improvestructure simplicityVSAvoidvibration power and lifespan

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent replaces the mechanical spring member with a magnetic field-based return mechanism. The magnetic flux-generating member and coil work together to generate magnetic force that returns the movable magnet to its initial position, eliminating the need for mechanical springs and their associated metal fatigue issues while providing controllable vibration power across different frequencies

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state from mechanical elastic deformation to magnetic field interaction. By controlling the coil current, the magnetic force can be dynamically adjusted to provide appropriate return force at various frequencies, overcoming the frequency limitation of mechanical springs

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a magnetic spring with another magnet attached to the housing is used, then the movable magnet can be returned to the initial position without a spring member, but the number of parts increases and the device size increases

Engineering Contradiction:

Improvespring memberless designVSAvoidnumber of parts and size

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the functions of the coil and magnetic flux-generating member into a single integrated return mechanism. The coil generates magnetic flux that interacts with the movable magnet, combining the electromagnetic actuation and return functions into one system rather than requiring separate magnetic spring components

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The coil serves dual functions: it generates electromagnetic force for actuation and generates magnetic flux for the return mechanism. This multi-functionality eliminates the need for additional magnets or separate return mechanisms, reducing part count while achieving spring memberless operation

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 provides effective vibration return without additional parts, reducing size and maintaining vibration power across frequencies, thus enhancing device performance and longevity.

Implementation Method 1

the movable magnet moves from an initial position by the action of an electromagnetic force

Methodology Applied

Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

The magnetic member is disposed so as to generate an attractive force to attract the movable body located at a position off a center of a movable range of the movable body, to the center of the movable range of the movable body

Methodology Applied

Scientific EffectMagnetic attraction: Magnetism

Data Source

PatentUS12537429B2Vibration generating device with movable body, guide member, magnetic member around coil

Publication Date: 2026.01.27 ALPS ALPINE CO LTD

AI summary

A vibration generating device includes: a stationary body; a movable body housed in the stationary body; a guide member configured to guide the movable body so that the movable body is reciprocally movable in the stationary body along a left-and-right direction; a magnetic flux-generating member fixed to the movable body and configured to generate a magnetic flux along an up-and-down direction; a coil fixed to the stationary body to cross the magnetic flux and includes electrically conductive wires extending along a front-and-back direction and being juxtaposed along the left-and-right direction; and a magnetic member fixed to the stationary body and disposed at an outer side of the coil. The magnetic member is disposed to generate an attractive force to attract the movable body located at a position off a center of a movable range of the movable body, to the center of the movable range of the movable body.