Variable Eccentric Cam Rheometer Amplitude Adjustment

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Solution Overview

Problem

Existing moving die rheometer systems require recalibration every time a different amplitude of oscillation is needed, leading to increased downtime due to phase shifts between the motor output and the oscillating die.

Innovation Solution

A variable eccentric cam system with an elongated channel and lock piece mechanism allows for precise positioning of the post using shims of different dimensions, enabling easy adjustment of the amplitude of oscillation without recalibration, by threading a shaft into the housing and using angled blocks to secure the shims in place.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the position of the post on the eccentric is changed to adjust amplitude, then the amplitude of oscillation can be changed, but the phase shifts between motor output and the die requiring recalibration increases downtime

Engineering Contradiction:
Improveamplitude adjustment capabilityVSAvoidrecalibration downtime
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent replaces manual mechanical adjustment and recalibration procedures with an automated feedback control system using sensors, processors, and actuators that automatically adjust the eccentric position and recalibrate the phase relationship, eliminating manual intervention and reducing downtime

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

Solution Approach 2:

The patent implements a feedback control system where sensors detect the actual position and phase of the oscillating die, the processor compares this with the target values, and actuators automatically adjust the eccentric position to maintain proper phase alignment, eliminating the need for manual recalibration after amplitude changes

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If multiple eccentrics are installed to change amplitude, then different amplitudes can be achieved, but the complexity of changing eccentrics and recalibration increases downtime

Engineering Contradiction:
Improveamplitude variation capabilityVSAvoideccentric replacement complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the single eccentric component multi-functional by enabling it to be precisely positioned at multiple locations along its travel path through automated control, allowing the same component to provide multiple amplitude settings without requiring multiple physical eccentrics

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

Solution Approach 2:

The patent replaces the mechanical system of multiple eccentrics with a single eccentric controlled by an automated positioning system using sensors and actuators, simplifying the hardware while expanding functionality through intelligent control

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

3Ease of operation

If the post position is altered on the eccentric, then amplitude can be adjusted, but maintaining constant phase requires time-consuming recalibration

Engineering Contradiction:
Improveamplitude adjustment easeVSAvoidphase alignment precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent uses feedback control where sensors continuously monitor the phase relationship between motor output and die oscillation, and the system automatically adjusts the eccentric position to maintain precise phase alignment, ensuring manufacturing-level precision without manual recalibration

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent enables the system to self-adjust and self-calibrate automatically after amplitude changes, with the control system detecting phase shifts and making corrective positioning adjustments without human intervention, maintaining precision while improving ease of operation

Inventive Principle:
Principle #25Self-service

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 precise changes in oscillation amplitude without recalibration, reducing downtime and maintaining consistent phase alignment, allowing for efficient polymer testing across various ASTM methods.

Implementation Method 1

a torque may be applied to the shaft to thread the shaft into the face to urge the lock piece against the first or second shim

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the lock piece includes two blocks, a first block to which the post is attached and a second block, and wherein a head of the shaft bears against the second block, and the second block bears against the first block to urge the first block against the shim

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP3207354B1Variable eccentric cam rheometer system
Publication Date: 2020.08.19 ALPHA TECHNOLOGIES SERVICES LLC
  • EP3207354B1 patent drawingFigure 1
  • EP3207354B1 patent drawingFigure 2
  • EP3207354B1 patent drawingFigure 3

AI summary

The present application relates generally to moving die rheometers, and more particularly to moving die rheometers that employ a variable eccentric cam. In one aspect, the eccentricity produced by the cam may be adjusted using shims of different thickness to alter the position of the post on the cam.