Stacked Orbital Shaker Imbalance Detection and Speed Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In multi-stack orbital shaker assemblies, identifying and addressing an out-of-balance condition in one device without manual intervention is challenging due to interconnected structures, leading to undesirable vibrations and instability.

Innovation Solution

Each orbital shaker device in the stack is equipped with a separate accelerometer and speed control unit, enabling automatic speed control through independent acceleration and vibration level determination, with speed adjustments made if thresholds are exceeded, allowing for parallel and asynchronous operation to identify the source of imbalance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If manual intervention is used to identify out-of-balance conditions in stacked orbital shakers, then the complexity of automatic detection is reduced, but the productivity and ease of operation deteriorate due to required user intervention

Engineering Contradiction:
Improveautomatic detection of out-of-balance conditionVSAvoidcomplexity of detection system
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The orbital shaker device automatically detects and identifies out-of-balance conditions through integrated vibration sensors and control units that monitor vibration levels and autonomously determine imbalance without requiring manual user intervention or complex external detection systems

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The device incorporates vibration sensors that continuously monitor vibration levels and feed this information back to the control unit, which automatically processes the data to detect out-of-balance conditions and triggers appropriate responses without user involvement

Inventive Principle:
Principle #23Feedback

2Stability of the object's composition

If the mass of non-rotating supporting structure is increased to resist forces from rotating mass, then stability improves, but the weight of the device increases

Engineering Contradiction:
Improvestability of orbital shakerVSAvoidweight of shaker device
Core Design Contradiction:
Stability of the object's compositionVSWeight of moving object

Solution Approach 1:

The patent employs counterweights that are rotationally accelerated in opposition to the orbitally-rotating mass to compensate for forces generated during operation, thereby maintaining stability without requiring increased mass of the non-rotating supporting structure

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The system dynamically adjusts the acceleration parameters of counterweights to match and oppose the forces generated by the rotating mass, providing active stabilization that avoids the need for excessive structural mass

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If counterweights are used to compensate forces from orbitally-rotating mass, then stability improves, but the device complexity increases

Engineering Contradiction:
Improvestability of orbital shakerVSAvoidcomplexity of stabilization mechanism
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The control unit integrates the monitoring of vibration levels and the control of counterweight acceleration into a single unified system, merging multiple functions into one compact control architecture that reduces overall device complexity while maintaining stabilization capability

Inventive Principle:
Principle #5Merging (Combining)

4Measurement precision

If vibration thresholds are set low for sensitive detection, then measurement precision improves, but false alarms increase due to mechanical connections in multi-stack assemblies

Engineering Contradiction:
Improvevibration level detection accuracyVSAvoidreliability of imbalance detection
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system divides the multi-stack assembly into individually monitored units, with each orbital shaker device equipped with its own vibration sensor and control unit that independently evaluates vibration data, allowing precise threshold detection without false alarms from mechanically connected devices

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control unit acts as an intermediary that processes vibration data and distinguishes between vibrations caused by actual imbalance in the monitored device versus vibrations transmitted from other mechanically connected devices in the stack

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

This method allows for the automatic detection and mitigation of out-of-balance conditions within the multi-stack assembly without user intervention, ensuring smooth operation and stability by independently adjusting the speed of each device based on its vibration levels, thereby preventing excessive vibrations and maintaining optimal performance.

Implementation Method 1

Each orbital shaker device comprises a separate accelerometer and a separate speed control unit

Methodology Applied
Scientific EffectAccelerometer: Accelerometer

Data Source

PatentEP3528936B1Method for automatic speed control of a stacked orbital shaker device to determine which one of the stacked orbital shakers is out of balance
Publication Date: 2022.06.15 EPPENDORF AG
  • EP3528936B1 patent drawingFigure 1
  • EP3528936B1 patent drawingFigure 2
  • EP3528936B1 patent drawingFigure 3

AI summary

A method for automatic speed control of an orbital shaker device (10, 11, 12) to determine one of at least two stacked orbital shaker devices (10, 11, 12) operating in an out of balance condition includes the steps of a) Starting the first orbital shaker device (10), b) Accelerating the first orbital shaker device (10), and c) Determining a vibration level of the first orbital shaker device (10), and d) Automatically decreasing a speed of the first orbital shaker device (10) if the vibration level determined in step c) exceeds a predefined first threshold, wherein the steps a) to d) are additionally executed for a second orbital shaker device (11) independently from the first orbital shaker device (10).