Fluidic Sample Shaker Using Offset Counterweight for Higher Mixing Frequencies

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Solution Overview

Problem

Existing shakers in automated analyser systems generate imbalances due to moving masses, limiting the maximum achievable shaking frequencies.

Innovation Solution

A shaker design incorporating a counterweight connected via a second eccentric drive with an offset to compensate for the inertia of the shaking plate, using elastic joints and spring bars to support and balance the masses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a linear shaker with eccentric drive is used to mix liquid samples, then mixing function is achieved, but imbalances and vibrations are generated throughout the system

Engineering Contradiction:
Improvemixing functionVSAvoidimbalances and vibrations
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a counterweight (mass2) that moves in opposition to the shaking plate mass (mass1) to compensate for imbalances. The counterweight is connected to a second eccentric drive with 180° offset, creating opposing inertial forces that cancel out the vibrations generated by the primary shaking mechanism, thereby eliminating harmful vibrations while maintaining mixing function.

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

Solution Approach 2:

The counterbalancing mechanism applies preliminary anti-action by generating opposing forces before the harmful vibrations can propagate through the system. The second eccentric drive and counterweight are positioned and timed to create counter-forces that preemptively neutralize the imbalances generated by the first eccentric drive.

Inventive Principle:
Principle #9Preliminary anti-action

2Productivity

If shaking frequency is increased to improve mixing efficiency, then productivity increases, but imbalances increase limiting maximum frequency

Engineering Contradiction:
Improvemixing efficiencyVSAvoidimbalances
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The counterweight system enables increased shaking frequencies by compensating for the increased imbalances that occur at higher frequencies. As frequency increases, the counterweight generates proportionally stronger opposing forces, maintaining balance and allowing the system to operate at higher productivity levels without being limited by vibration-induced instability.

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

3Speed

If a counterweight with 180° offset is added to compensate for imbalances, then shaking frequency can be increased, but device complexity increases

Engineering Contradiction:
Improveshaking frequencyVSAvoidstructure complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent merges the counterbalancing function with the existing drive mechanism by using a second eccentric drive connected to the same motor axis. This integration approach allows the counterweight system to be added without requiring a separate motor or independent drive system, thereby reducing the increase in device complexity while still achieving the goal of enabling higher shaking frequencies.

Inventive Principle:
Principle #5Merging (Combining)

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

Reduces imbalances during shaking, enabling higher mixing frequencies and extending the reliability and lifespan of components.

Implementation Method 1

a first linking rod (11) of a shaker according to the present disclosure is connected to a first eccentric drive (10) which is connected to a rotating axis (15)

Methodology Applied
Scientific EffectEccentric drive: Eccentric

Implementation Method 2

a counterweight (40) which is connected by a second linking rod (21) to a second eccentric drive (20) which is connected to the axis (15) with an offset to the first eccentric drive (10)

Methodology Applied
Scientific EffectEccentric drive: Eccentric

Implementation Method 3

The first linking rod of a shaker according to the present disclosur is in an embodiment connected to a first elastic joint which is connected to the shaking plate

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 4

The first and second elastic joint have identical masses in an embodiment of a shaker according to the present disclosure

Methodology Applied
Scientific EffectVibration damping: Damping

Implementation Method 5

The shaking plate of a shaker according to the present disclosure rests in an embodiment on at least two spring bars

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 6

a motor which rotates the axis to which first and second eccentric drive are connected

Methodology Applied
Scientific EffectElectric motor: Linear Motor

Data Source

PatentEP4603175A1Imbalance compensated shaker for mixing fluidic samples
Publication Date: 2025.08.20 STRATEC SE
  • EP4603175A1 patent drawingFigure 1~2
  • EP4603175A1 patent drawingFigure 3~4
  • EP4603175A1 patent drawingFigure 5~6

AI summary

The present disclosure relates to a shaker for actuating a fluidic sample in a container, comprising a first mass from the following components: - a shaking plate (5) which is connected by a first linking rod (11) to a first eccentric drive (10) which is connected to an axis (15); - a second mass from the following components which is moved in opposition to the first mass: a counterweight (40) which is connected by a second linking rod (21) to a second eccentric drive (20) which is connected to the axis (15) with an offset to the first eccentric drive (10); and - a motor (30) which rotates the axis (15) to which first and second eccentric drives (10, 20) are connected.