Micropump Flow Rate Control via Variable Frequency Drive

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Solution Overview

Problem

Existing pumps, particularly micropumps, are inflexible and costly due to the need for different sizes to accommodate varying flow rate requirements in applications like steam irons and coffee machines, necessitating high production and storage costs for specific components.

Innovation Solution

A micropump with a control device that modifies the frequency of the electric current pulses in the coil to adjust the flow rate, allowing the same pump to be used across different applications by converting alternate electric voltage into continuous voltage and setting a desired frequency independent of the network frequency, using a convertor unit and frequency setting unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If different pumps with different sizes are produced to accommodate varying flow rate requirements, then the pump can meet specific application needs, but production costs and storage costs increase significantly

Engineering Contradiction:
Improveflow rate adaptabilityVSAvoidproduction cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent changes the electrical parameter (frequency of pulsed current) to achieve different flow rates instead of changing mechanical parameters (pump size). The control device varies the frequency of pulsed current supplied to the electromagnetic drive, allowing a single pump design to deliver multiple flow rates, thereby resolving the contradiction between adaptability and manufacturing cost.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent makes a single pump design universal by enabling it to perform multiple functions (deliver different flow rates) through electrical control. The pump can be adjusted to meet various application requirements without requiring physically different pump models, thus eliminating the need for producing and storing multiple pump sizes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If different pumps with different sizes are produced to accommodate varying flow rate requirements, then the pump can meet specific application needs, but storage space requirements increase

Engineering Contradiction:
Improveflow rate adaptabilityVSAvoidstorage space
Core Design Contradiction:
Adaptability or versatilityVSVolume of stationary object

Solution Approach 1:

The patent creates a universal pump that can serve multiple applications with different flow rate requirements through electrical frequency control. Instead of storing multiple physically different pump models, only one pump design needs to be stored and distributed, significantly reducing storage space requirements while maintaining full adaptability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If the frequency of pulsed current is modified to regulate flow rate, then the pump can adapt to different conditions, but the control system complexity increases

Engineering Contradiction:
Improveflow rate regulationVSAvoidcontrol device complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical adjustment mechanisms (such as variable displacement mechanisms or mechanical valves) with an electrical control system that modifies the frequency of pulsed current. This substitution simplifies the overall device architecture while achieving flow rate regulation, as electrical frequency control is more compact and easier to implement than mechanical adjustment systems.

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

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

Enables quick and economical adaptation of the pump's flow rate to various conditions, reducing production and storage costs while optimizing energy consumption and versatility in multiple applications.

Implementation Method 1

the suction and delivery means are moved by the electromagnetic force generated by the electric current circulating in the coil

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

in which the piston is moved in one direction by the electromagnetic force, and in the opposite direction by an elastic force exerted by the elastic means

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP3456965B1Pump, and corresponding control method
Publication Date: 2023.05.10 ROBERTSHAW ITAL SRL
  • EP3456965B1 patent drawingFigure 1~2

AI summary

A pump comprises means to suck in and deliver a fluid, and a coil (14) connectable to an electric power source (18) configured to feed an alternate electric voltage (VAC). The coil (14) is suitable to move the suction and delivery means in order to suck in and deliver the fluid as a function of a pulsed electric current (I) circulating therein. The pump also comprises a control device (20) configured to regulate the flow rate of the pump, comprising a convertor unit (22) configured to convert the alternate electric voltage (VAC) into a substantially continuous electric voltage (VDC), and a frequency setting unit (28), configured to selectively and periodically feed the continuous electric voltage (VDC) to the coil (14).