Reference Vibrator for Unbalance Measurement Repeatability

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Solution Overview

Problem

Conventional unbalance measurement devices face challenges in accurately checking repeatability due to variations in vibration force caused by environmental changes and degradation of reference rotors, making it difficult to distinguish between rotor and device repeatability issues.

Innovation Solution

A reference vibrator with a unidirectional vibration generator, such as an inertial vibrator, is used to apply stable vibrations to the unbalance measurement device, with a force sensor to measure and correct vibration force variations, and two crossed vibration generators forming a Lissajous circle to simulate rotary product vibrations accurately.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a reference rotor is used to check repeatability, then the unbalance measurement device can be calibrated, but the vibration force varies due to environmental changes and rotor degradation

Engineering Contradiction:
Improverepeatability of unbalance measurementVSAvoidstability of vibration force
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent creates a reference vibrator that copies the essential vibration characteristics of a reference rotor without using an actual rotating rotor. By using a vibration generator that produces vibrations equivalent to those of a reference rotor, the system eliminates the degradation and environmental sensitivity issues while maintaining the calibration function.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical rotation system (reference rotor) with a vibration generation system (vibration generator). This substitution eliminates the need for mechanical rotation while producing the same vibrational effects, thereby avoiding issues related to rotor degradation, balancing accuracy, and environmental sensitivity.

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

2Measurement precision

If a reference rotor with excellent vibration properties is used, then calibration can be performed, but it is difficult to distinguish between rotor and device repeatability issues

Engineering Contradiction:
Improvecalibration accuracyVSAvoiddifficulty in diagnosing repeatability issues
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The reference vibrator creates a simplified copy of the reference rotor's function, producing vibrations without the complex mechanical rotation system. This eliminates the ambiguity of whether repeatability issues stem from the rotor or the measurement device, as the vibration source is now a controlled generator rather than a mechanical rotor.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent extracts the essential vibration-generating function from the reference rotor, separating it from the mechanical rotation components. By using only the vibration generation capability without the rotating mass and mechanical structure, the system simplifies the calibration process and eliminates diagnostic complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If a rotary product is rotated for measurement, then unbalance amount can be detected, but vibration force varies with rotation speed and mounting conditions

Engineering Contradiction:
Improveunbalance detection accuracyVSAvoidvibration force consistency
Core Design Contradiction:
Measurement precisionVSForce

Solution Approach 1:

The patent replaces the mechanical rotation system with a vibration generation system. Instead of rotating the product at various speeds to generate vibration, a vibration generator directly produces the required vibrations, eliminating variations due to rotation speed and mounting conditions while maintaining measurement accuracy.

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

This approach ensures high repeatability of vibration force application, allowing for precise checking and calibration of the unbalance measurement device by eliminating variations and simulating rotary product vibrations effectively.

Implementation Method 1

the unidirectional vibrator is an inertial vibrator that generates a vibration force by a reaction force of vibrations of an inertial mass

Methodology Applied
Scientific EffectInertia: Inertia

Implementation Method 2

vibration is caused by the vibration generator fixed to the vibrator body

Methodology Applied
Scientific EffectVibration: Vibration

Data Source

PatentEP2280264B1Standard exciter
Publication Date: 2020.04.29 IHI CORP
  • EP2280264B1 patent drawingFigure 1
  • EP2280264B1 patent drawingFigure 2
  • EP2280264B1 patent drawingFigure 3

AI summary

Repeatability of an unbalance measurement device is properly checked. A reference vibrator 10 of the present invention includes: a vibrator body 11 configured to be mounted to a mount 4 in an unbalance measurement device 1 to which a rotary product is mounted at the time of unbalance measurement, in a same mounting state as the rotary product; a vibration generator 12 that is fixed to the vibrator body 11 and applies vibrations to the vibrator body 11; and a control unit 13 that controls the vibration generator 12. Since vibration is caused by the vibration generator 12 fixed to the vibrator body 11, repeatability of a vibration force is high. This makes it possible to apply vibrations for repeatability check to the unbalance measurement device 1 with an accurate vibration force. Thus, variations in vibration force can be eliminated, and the repeatability of the unbalance measurement device 1 can be properly checked.