Inner-Guided Vibration Actuator for Impact-Stable Coil Retention

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Solution Overview

Problem

Conventional vibration actuators suffer from reduced vibration performance and durability, and potential operation failures and noise due to external impacts, which can cause deformation and damage to electromagnetic components, especially in mobile devices and game controllers.

Innovation Solution

A vibration actuator design featuring a cylindrical casing with a leaf spring support system and inner guides that restrict movement, where the casing and inner guides are welded together, and coils are positioned with extending portions to sandwich and secure the coils, preventing them from coming off during impacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the movable element is supported only by a rubber supporting component, then the structure is simple, but the movable element contacts the coil during radial movement causing operation failure and noise

Engineering Contradiction:
Improvestructure simplicityVSAvoidoperation reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

An inner guide component is introduced as an intermediary between the movable element and the coil. The inner guide includes a guide hole through which the movable element passes, restricting its movement to the axial direction and preventing radial contact with the coil. This mediator resolves the contradiction by adding a simple structural element that ensures reliable operation without significantly increasing complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the inner circumference of the coil is covered by a bobbin, then the movable element and coil are not in direct contact, but heat dissipation of the coil is reduced and insulation may deteriorate faster

Engineering Contradiction:
Improveinsulation durabilityVSAvoidheat dissipation efficiency
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The bobbin covering the entire coil is removed, extracting the harmful insulation barrier. Instead, an inner guide structure is used to prevent contact between the movable element and coil, while leaving the coil exposed for efficient heat dissipation. This resolves the contradiction by eliminating the insulation problem through a different structural approach that maintains thermal performance.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of manufacture

If adhesion by adhesives is used to join the coil casing and coil, then the assembly is simple, but the joining may break during impact causing operation failure

Engineering Contradiction:
Improveassembly simplicityVSAvoidjoining strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The inner guide structure is merged with the coil assembly, where the inner guide extends to sandwich and secure the coil between itself and the coil casing. This combination of mechanical support and positioning structures creates a unified assembly that maintains simple manufacturing while providing impact-resistant joining through distributed mechanical constraints rather than relying solely on adhesive bonds.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances the vibration actuator's durability and prevents operation failures and noise by restricting excessive movement and ensuring the coils remain securely attached, maintaining performance and heat dissipation while reducing the risk of insulation deterioration.

Implementation Method 1

a vibration actuator (1) mainly includes a cylindrical casing (2) having both opened ends, a movable element (4) arranged inside the casing (2) and capable of reciprocating along an axis (O) inside the casing (2), and a casing-side electromagnetic driving portion (3) provided inside the casing (2) and driving the movable element (4) to vibrate

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

a vibration actuator having a structure in which a shaft (axis) along the vibration direction penetrates the movable element, and since the movable element vibrates along the shaft, movement is the radial direction is restricted

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3932568B1Vibration actuator
Publication Date: 2024.02.28 FOSTER ELECTRIC CO LTD
  • EP3932568B1 patent drawingFigure 1
  • EP3932568B1 patent drawingFigure 2
  • EP3932568B1 patent drawingFigure 3

AI summary

[Problem] To provide a vibration actuator that can protect against deterioration in vibration performance and durability of the vibration actuator and that can prevent malfunctions and abnormal noises even if an external impact occurs. [Solution] A vibration actuator 1 comprises: a cylindrical case 2 that has a first coil 21a and a second coil 21b; a movable part 4 that is disposed inside the case 2 and that has a magnet 30; and a first inner guide 6a and a second inner guide 6b that have extensions 65a, 65b located between the movable part 4 and the first coil 21a and second coil 21b and sandwiching the first coil 21a and the second coil 21b with the case 2.