Piezoelectric Pump Protrusion Suppresses Backflow

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Solution Overview

Problem

Pumps with piezoelectric bodies that rely on vibrating plates for valve function experience fluid backflow due to pressure changes, leading to reduced flow rates and pressures.

Innovation Solution

A pump design featuring a vibrating plate with a piezoelectric body, a cover with a top plate and side wall, support portions, and protrusions to minimize backflow, where the protrusions are strategically placed between the top plate and side wall openings, enhancing flow rate and pressure by reducing fluid recirculation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the valve body function is realized by vibration of a vibrating plate, then the device complexity is reduced, but fluid backflow occurs and pump performance deteriorates

Engineering Contradiction:
ImprovestructureVSAvoidbackflow
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The pump chamber is segmented into multiple regions by dividing the opening into first and second openings, with the vibrating plate positioned between them. This segmentation allows separate control of fluid flow paths, enabling the system to maintain simplicity while preventing backflow through strategic placement of the vibrating plate and openings.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the pump chamber are given different functions: the first opening region allows fluid entry, the vibrating plate region creates pressure changes, and the second opening region handles discharge. This local differentiation of functions enables the simple vibrating plate structure to achieve reliable backflow prevention through spatial functional distribution.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If the vibrating plate is used for valve function, then manufacturing is simplified, but pump flow rate and pressure are reduced due to backflow

Engineering Contradiction:
Improvevalve bodyVSAvoidpump flow rate
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The vibrating plate performs multiple dynamic functions: it acts as a valve to open/close flow paths, generates pressure changes through vibration, and controls fluid direction. This dynamic multi-functionality allows the simple vibrating plate structure to achieve reliable backflow prevention and maintain pump performance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The piezoelectric element generates periodic vibrations of the vibrating plate, creating rhythmic pressure changes that drive fluid flow through the pump chamber. This periodic action enables the simple structure to achieve effective fluid transport and backflow prevention through controlled oscillation cycles.

Inventive Principle:
Principle #19Periodic action

3Power

If pressure changes occur in the pump chamber, then fluid pumping is achieved, but backflow occurs from intake and discharge ports into the pump chamber

Engineering Contradiction:
Improvepump pressureVSAvoidbackflow
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The vibrating plate serves as an intermediary element between the first and second openings, controlling fluid flow through its vibration-induced position changes. This intermediary structure enables pressure-driven fluid pumping while preventing direct backflow paths, as the vibrating plate dynamically blocks reverse flow during pressure changes.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 fluid backflow, increasing pump flow rate and pressure by optimizing the vibrational displacement and air resistance within the pump chamber.

Implementation Method 1

a vibrating plate having a piezoelectric body connected to a first main surface

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3828414B1pump
Publication Date: 2024.08.14 MURATA MFG CO LTD
  • EP3828414B1 patent drawingFigure 1
  • EP3828414B1 patent drawingFigure 2A
  • EP3828414B1 patent drawingFigure 2B

AI summary

The present invention includes: a vibrating plate having a piezoelectric body connected to a first main surface thereof; a cover including a top plate that faces a second main surface of the vibrating plate, which is on the opposite side from the first main surface, and that has an opening part, and a side wall that is connected to an outer peripheral portion of the top plate so as to surround a space between the top plate and the vibrating plate; a support portion that is connected to the side wall and supports an outer periphery of the vibrating plate; an opening that is formed between the side wall and the vibrating plate; and a protrusion that is provided on any one out of the top plate, the side wall, and the vibrating plate so as to protrude into the space. The protrusion is provided between the opening part of the top plate and the side wall in a cross section viewed in a direction perpendicular to a direction in which a main surface of the top plate and the second main surface of the vibrating plate face each other.