Stirring Device Vibration Detection and Motor Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Laboratory stirrers with long shafts often experience vibrations and imbalances, which can lead to damage, especially when immersed in glass jars, due to manufacturing tolerances and material properties, posing a risk of destruction.

Innovation Solution

Incorporating a vibration sensor, such as an acceleration sensor, connected to the drive motor's control circuit, which can alert the user and adjust or stop the motor to prevent damage from imbalances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a long shaft is used for the stirring tool, then the stirring device can reach deeper into glass jars and stir larger volumes, but vibrations and imbalances occur more frequently leading to potential damage

Engineering Contradiction:
Improvestirring volumeVSAvoidoperational reliability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent applies preliminary action by detecting vibrations and imbalances before they cause damage. The sensor system continuously monitors the stirring shaft during operation and triggers warnings or shutdowns proactively, preventing catastrophic failures of the glass jar or stirring tool before they occur.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If manufacturing tolerances are relaxed to reduce costs, then production becomes easier and cheaper, but vibrations and imbalances increase due to higher variability in shaft and stirring tool dimensions

Engineering Contradiction:
Improvemanufacturing easeVSAvoidvibrations
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent implements feedback by using sensors to detect vibrations and imbalances generated by the stirring tool and shaft. This feedback loop allows the system to monitor the actual performance, identify when manufacturing tolerances result in problematic variations, and respond by warning the user or shutting down to prevent damage.

Inventive Principle:
Principle #23Feedback

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 solution effectively detects and mitigates vibrations and imbalances in real-time, preventing potential damage to the stirring device and its surroundings.

Implementation Method 1

the sensor that responds to imbalance is an acceleration sensor

Methodology Applied
Scientific EffectAcceleration sensing: Accelerometer

Implementation Method 2

An expedient embodiment of the sensor in particular can provide for it to be piezo-based

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 3

inductive with a plunger coil

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 4

by means of strain gauges

Methodology Applied
Scientific EffectStrain gauge measurement:

Data Source

PatentEP2714257B2Stirring device comprising a stirring tool and a drive motor
Publication Date: 2018.09.05 IKA WERKE GMBH & CO KG
  • EP2714257B2 patent drawingFigure 1~4

AI summary

The invention relates to a stirring device (1) that comprises a stirring tool which can be introduced into a mass or liquid that is to be stirred, a drive motor (4) that drives said stirring tool, a housing (5) enclosing said drive motor (4) and a fastening point (6) for securing said stirring device in a working position. The stirring device (1) has at least one sensor (11) for detecting imbalances which preferably is linked or connected to the open- and closed-loop control systems of the drive motor (4), and which can switch off said drive motor (4) or change the speed thereof in the event of undesired or dangerous oscillations or vibrations.