Personal Care Drive System Active Vibration Dampening

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Resonant high-frequency personal care appliances, such as automatic toothbrushes, generate undesirable vibrations that cause user discomfort due to the transfer of high-frequency brushing actions from the brush head to the handle.

Innovation Solution

A resonant high-frequency drive system with active vibration dampening is implemented, utilizing a stator and rotor configuration with electromagnets and biasing members to create a magnetic field that drives the stator and rotor out of phase, allowing the stator to reciprocate linearly and rotationally to dampen vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If resonant high-frequency drive system is used to achieve effective cleaning, then cleaning effectiveness is improved, but vibration transferred to handle increases causing user discomfort

Engineering Contradiction:

Improvecleaning effectivenessVSAvoidvibration transferred to handle

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies active vibration dampening that generates counter-vibrations to cancel out the harmful vibrations transferred to the handle. The system converts the harmful vibration energy into beneficial counteracting motion, reducing net vibration at the handle while preserving the high-frequency brushing action at the brush head for effective cleaning.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces an intermediary vibration dampening system between the drive mechanism and the handle. This intermediary system actively generates opposing vibrations to neutralize the harmful vibrations, acting as a mediator that allows the high-frequency drive to function effectively while protecting the user from discomfort.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If high-frequency brushing action is used to remove debris and plaque, then cleaning performance is improved, but vibration is transferred to the handle causing user discomfort

Engineering Contradiction:

Improvecleaning performanceVSAvoidvibration transferred to handle

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The active vibration dampening system converts the harmful vibration that reaches the handle into beneficial counter-vibrations. By generating opposing vibrational forces, the system neutralizes the discomfort-causing vibrations while allowing the high-frequency brushing action to continue uninterrupted for effective plaque and debris removal.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the vibrational parameters (frequency, amplitude, phase) of the dampening mechanism to optimize the cancellation effect. By carefully controlling these parameters, the system achieves maximum vibration reduction at the handle while preserving the cleaning effectiveness at the brush head, resolving the contradiction between cleaning performance and user comfort.

Inventive Principle:

Principle #35Parameter changes

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 system effectively reduces linear and rotational vibrations, enhancing user comfort by attenuating the vibration transferred to the handle, while maintaining the high-frequency brushing action for effective cleaning.

Implementation Method 1

at least one electromagnet to generate a magnetic field, and/or at least one magnet which interacts with the magnetic field of the at least one electromagnet to reciprocally drive the rotor and the stator casing linearly and rotationally out of phase with each other

Methodology Applied

Scientific EffectElectromagnetic interaction: Electromagnetic Induction

Implementation Method 2

first and second biasing members... the stator casing situated between and linearly biased by the first and second biasing members

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP3157462B1Drive system for personal-care appliance

Publication Date: 2019.12.04 KONINKLIJKE PHILIPS NV

Figure 1~2
Figure 3
Figure 4A~5

AI summary

A power toothbrush apparatus may include a body having a cavity and an opening leading to the cavity. An electric motor may be situated within the cavity and may include first and second biasing members; a stator casing situated between, and linearly biased by, the first and second biasing members, the stator casing may further include at least one opening and at least one electromagnet to generate a magnetic field; and a rotor which may have opposed ends and which may extend through the at least one opening of the stator casing, the rotor may further include an output shaft. The power toothbrush may further include a workpiece having a brush head coupled thereto and which may be coupled to one of the opposed ends of the output shaft.