Dual-Cavity Pump Actuator Isolator High-Frequency Efficiency

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Solution Overview

Problem

Conventional pumps operating at high frequencies for portable electronic devices face challenges in maintaining efficiency due to dampening effects at the interface between the driven end wall and side wall in disc-shaped cavities, and existing valves are not capable of responding to high-frequency oscillations required for efficient fluid flow.

Innovation Solution

A disc pump design with a dual-cavity structure and actuator-mounted valves that include a flexible isolator to minimize dampening and a flap valve mechanism allowing rapid response to pressure changes, enabling efficient fluid flow at high frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a disc-shaped cavity with high aspect ratio is used to achieve high frequency operation, then the pump size is reduced and operating frequency is increased, but dampening effects at the interface between driven end wall and side wall reduce efficiency

Engineering Contradiction:
Improveoperating frequencyVSAvoidefficiency
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

An isolator is introduced as an intermediary component between the driven end wall and the side wall. This isolator minimizes dampening effects by decoupling the interface, allowing the end wall to oscillate with larger amplitude without energy loss to the side wall, thereby maintaining efficiency at high operating frequencies

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The isolator is implemented as a flexible diaphragm or membrane that can accommodate the oscillatory motion of the driven end wall while maintaining the structural integrity of the cavity. This flexible structure reduces mechanical constraints and dampening at the interface, enabling efficient high-frequency operation

Inventive Principle:
Principle #30Flexible shells and thin films

2Speed

If conventional valves are used to control fluid flow, then the structure is simple, but the valves cannot respond rapidly enough to high-frequency pressure oscillations

Engineering Contradiction:
Improvevalve response speedVSAvoidvalve structure
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

Conventional mechanical valves with moving parts are replaced with acoustic valves that utilize acoustic radiation pressure and standing wave patterns to control fluid flow. This substitution eliminates complex mechanical actuation mechanisms, enabling rapid response to high-frequency pressure oscillations without mechanical inertia limitations

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The acoustic valve utilizes periodic pressure oscillations at the resonant frequency of the cavity to create rectified flow. By synchronizing the valve operation with the periodic pressure waves, the system achieves rapid, repeated opening and closing actions that enable high-frequency fluid control without mechanical wear or inertia

Inventive Principle:
Principle #19Periodic action

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 enhances the amplitude of pressure oscillations and maintains efficiency by reducing dampening effects, allowing the pump to operate effectively at high frequencies with improved fluid flow control.

Implementation Method 1

the generation of high amplitude pressure oscillations in closed cavities has received significant attention in the fields of thermo-acoustics and pump type compressors

Methodology Applied
Scientific EffectAcoustic resonance: Resonance

Implementation Method 2

the acoustic pressure wave has limited amplitude. Varying cross-section cavities, such as cone, horn-cone, bulb have been used to achieve high amplitude pressure oscillations

Methodology Applied
Scientific EffectAcoustic radiation pressure: Acoustic Radiation Pressure

Implementation Method 3

A portion of the driven end wall between the actuator and the side wall provides an interface with the side wall of the pump that decreases dampening of the displacement oscillations

Methodology Applied
Scientific EffectDampening reduction: Damping

Implementation Method 4

valves being capable of operating at high frequencies. Conventional valves typically operate at lower frequencies below 500 Hz

Methodology Applied
Scientific EffectPressure oscillation rectification: Pressure Gradient

Data Source

PatentEP2758666B1Dual-cavity pump
Publication Date: 2020.07.22 3M INNOVATIVE PROPERTIES CO
  • EP2758666B1 patent drawingFigure 1A~1B
  • EP2758666B1 patent drawingFigure 1C
  • EP2758666B1 patent drawingFigure 2A~3

AI summary

A dual-cavity pump having a pump body with a substantially elliptical shape including a cylindrical wall (11) closed at each end by end plates (12,13) is disclosed. The pump (10) further comprises a pair of disc-shaped interior plates (14,15) supported within the pump by a ring-shaped isolator (30) affixed to the cylindrical wall of the pump body. The internal surfaces of the cylindrical wall (11), the end plate (12), the interior plate (14), and the ring-shaped isolator (30) form a first cavity (16) within the pump. The internal surfaces of the cylindrical wall (11), the end plate (13), the interior plate (15), and the ring-shaped isolator (30) form a second cavity (17) within the pump. The internal surfaces of the first cavity (16) comprise a side wall (18) which is a first portion of the inside surface of the cylindrical wall (11) that is closed at both ends by end walls (20,22) wherein the end wall (20) is the internal surface of the end plate (12) and the end wall (22) comprises the internal surface of the interior plate 14 and a first side of the isolator (30):. The interior plates (14,15) together form an actuator (40) that is operatively associated with the central portion of the end walls (22,23) via the interior plates (22,23). The illustrative embodiments of the dual-cavity pump have three valves including one located within a common end wall between the cavities of the pump.