Electric Toothbrush Drive Structure for Lower Hand Vibration

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Solution Overview

Problem

Existing electric toothbrushes transmit significant vibration to the hand during use, which can be uncomfortable and may cause fatigue.

Innovation Solution

The electric toothbrush is designed with a D-cut structure in the body to minimize vibration transmission, incorporating a D-cut drive shaft and a power transmission mechanism that attaches to the brush handle, using hooks and vibration receivers to stabilize the connection and reduce vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a rotary motor and eccentric weight are incorporated in the body to generate vibration for cleaning, then brushing function is achieved, but vibration is transmitted to the hand causing discomfort and fatigue

Engineering Contradiction:
Improvebrushing functionVSAvoidvibration transmission to hand
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The body is divided into multiple sections with different rigidities along the longitudinal direction. The front portion has higher rigidity to effectively transmit vibration to the brush handle for cleaning, while the rear portion has lower rigidity to absorb and reduce vibration transmission to the user's hand, thus resolving the contradiction between maintaining brushing function and reducing harmful vibration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The body employs asymmetric rigidity distribution along its longitudinal axis rather than uniform rigidity. This asymmetric design allows the front section to be rigid for effective vibration transmission to the brush, while the rear section is made more flexible to protect the user's hand from excessive vibration, thereby solving the technical contradiction.

Inventive Principle:
Principle #4Asymmetry

2Object-affected harmful factors

If the body structure is made more complex with vibration suppression mechanisms, then vibration transmission is reduced, but device complexity increases

Engineering Contradiction:
Improvevibration transmissionVSAvoidbody structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent changes the physical parameter of rigidity along the longitudinal direction of the body by varying the thickness of the wall portions. The front portion has greater wall thickness for higher rigidity, while the rear portion has reduced wall thickness for lower rigidity. This parameter change approach achieves vibration suppression through structural design rather than adding separate vibration isolation components, thus reducing device complexity while still effectively reducing vibration transmission.

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 design effectively suppresses vibration transmission to the hand, providing a more comfortable brushing experience and reducing user fatigue.

Implementation Method 1

By driving the rotary motor to rotate the eccentric weight, vibration is generated in the body, and the vibration generated by the eccentric weight is transmitted from the body to the bristles of the brush handle

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

a rotary motor and an eccentric weight attached to a motor shaft of the rotary motor are incorporated in the body. By driving the rotary motor to rotate the eccentric weight, vibration is generated in the body

Methodology Applied
Scientific EffectEccentric rotation: Eccentric

Data Source

PatentEP4321052B1Electric toothbrush
Publication Date: 2025.12.10 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP4321052B1 patent drawingFigure 1
  • EP4321052B1 patent drawingFigure 2
  • EP4321052B1 patent drawingFigure 3~4

AI summary

The present disclosure provides an electric toothbrush capable of more reliably suppressing transmission of vibration generated during use to the hand. Electric toothbrush (1) according to the present disclosure includes body (10) having drive shaft (16) driven by rotary motor (15). In addition, electric toothbrush (1) further includes head (20) detachably attached to body (10), head (20) including power transmission mechanism (24) capable of transmitting power of rotary motor (15), and acting member (25) operated by the power transmitted from power transmission mechanism (24). Further, electric toothbrush (1) includes brush handle (30) having bristle (3131) and detachably attached to head (20). Then, power transmission mechanism (24) includes power transmission unit (241) attachable to drive shaft (16) in a state where idling is suppressed.