Electric Toothbrush Vibration Transmission via Point Contact

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Solution Overview

Problem

Existing electric toothbrushes face challenges in suppressing vibration energy loss while minimizing the vibration felt by the user's hand during brushing, as conventional methods either absorb vibration energy inefficiently or increase slidable movement resistance and operation noise.

Innovation Solution

An electric toothbrush design featuring a vibration transmitting component that point contacts the outer case at multiple locations, using a stem with an eccentric shaft bearing and an elastic member to absorb vibrations, thereby reducing energy loss and minimizing hand vibration while maintaining efficient vibration transmission to the brush portion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a vibration proof member is arranged to absorb vibration near the end of the inner case, then the vibration of the portion the user grips is reduced, but vibration energy is lost

Engineering Contradiction:

Improvehand vibrationVSAvoidvibration energy loss

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The patent introduces a vibration transmitting component as an intermediary element between the eccentric shaft and the outer case. This component selectively transmits vibration to the brush portion while blocking vibration transmission to the outer case through its specific structural design with multiple contact points, thereby reducing hand vibration without energy loss

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The vibration transmitting component is designed with multiple separate contact points (first contact point, second contact point, third contact point) distributed at different locations. This segmentation allows the component to independently manage vibration transmission paths, enabling selective vibration transmission to the brush while preventing transmission to the handle

Inventive Principle:

Principle #1Segmentation

2Productivity

If an eccentric shaft bearing is arranged near the brush portion to vibrate the brush, then brush vibration is improved, but slidable movement resistance and operation sound increase

Engineering Contradiction:

Improvebrush vibration efficiencyVSAvoidoperation sound and vibration

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The vibration transmitting component serves as a mediator that decouples the eccentric shaft from direct contact with the outer case. By providing multiple controlled contact points, it maintains efficient vibration transmission to the brush while preventing the propagation of harmful vibrations and noise to the handle, thus resolving the contradiction between vibration efficiency and operation sound

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If the vibration transmitting component contacts the outer case at multiple locations, then hand vibration is suppressed, but the movement of the component is limited

Engineering Contradiction:

Improvehand vibrationVSAvoidcomponent movement freedom

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The vibration transmitting component is designed with multiple contact points that dynamically adapt to vibration conditions. During normal operation, these contact points allow controlled movement freedom for vibration transmission, while during high-vibration periods, they engage to suppress transmission to the outer case, providing dynamic response to different operational states

Inventive Principle:

Principle #15Dynamics

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 effectively suppresses hand vibration and energy loss while ensuring efficient vibration transmission to the brush portion, enhancing user comfort and maintaining long-term stability and noise reduction.

Implementation Method 1

a vibration transmitting component which transmits a vibration generated with the rotation of the eccentric shaft to a brush portion; wherein the vibration transmitting component is positioned with respect to the outer case by point contacting an inner wall surface of the outer case at a plurality of locations

Methodology Applied

Scientific EffectVibration absorption: Damping

Implementation Method 2

an eccentric shaft which center of gravity is arranged at a position shifted from a shaft center and which rotates by a drive force of the drive source

Methodology Applied

Scientific EffectEccentric rotation: Eccentric

Data Source

PatentUS9439742B2Electric toothbrush

Publication Date: 2016.09.13 OMRON HEALTHCARE CO LTD

AI summary

An electric toothbrush includes an inner case, made up of an inner case main body and a motor holder, mounted with various components including a motor; an outer case which interiorly accommodates the inner case and which acts as a portion the user grips with hand when brushing teeth; an eccentric shaft, configured by a shaft main body and an eccentric member, which center of gravity is arranged at a position shifted from a shaft center and which rotates by a drive force of the motor; and a vibration transmitting component for transmitting the vibration generated with the rotation of the eccentric shaft to a brush portion; where the vibration transmitting component is positioned with respect to the outer case by point contacting the inner wall surface of the outer case at a plurality of locations.