Active Damping Elements for Electrodynamic Machine Vibration Control

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Solution Overview

Problem

Electrodynamic machines, such as induction motors, experience high vibrations due to unbalanced and electromagnetic forces, which can lead to damage when excitation frequencies coincide with natural frequencies, especially when operated with variable frequency drives that alter AC excitation frequencies within a wide range.

Innovation Solution

Incorporating active damping elements, such as electromechanical solenoids, to counteract structural vibrations by applying adaptive counter-vibrations that cancel out natural frequencies, and damping elements to reduce unbalanced forces, thereby minimizing vibration levels across varying AC excitation frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If variable frequency drives are used to vary AC excitation frequencies from 30 Hz to 75 Hz, then motor speed control flexibility is improved, but motor vibration increases proportionally across a wider frequency range

Engineering Contradiction:

Improvemotor speed control flexibilityVSAvoidmotor vibration

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies active vibration control by generating counter-vibrations using exciters that produce mechanical vibrations opposite in phase to the harmful vibrations. Sensors detect the harmful vibrations across the frequency range, and the exciters generate compensating vibrations to cancel them out, allowing the motor to operate across variable frequencies with reduced vibration.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The patent implements a feedback control system where sensors continuously monitor vibration levels across the frequency spectrum, and this information is used to adjust the counter-vibration generation in real-time. The control system processes sensor signals and adjusts exciter activation to maintain optimal vibration cancellation across varying operating conditions and frequencies.

Inventive Principle:

Principle #23Feedback

2Object-affected harmful factors

If structural components are designed with low structural vibration, then natural frequencies are shifted away from operating frequencies, but device complexity increases

Engineering Contradiction:

Improvestructural vibrationVSAvoidstructural design complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent introduces damping elements as intermediary components between the structural components and the harmful vibrations. These damping elements absorb and dissipate vibrational energy, acting as a mediator that reduces vibration transmission without requiring fundamental changes to the structural design or natural frequencies of the motor components.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If damping elements are added to reduce unbalanced forces, then vibration reduction is achieved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improveunbalanced forcesVSAvoidcomponent quantity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent employs active control parameters by dynamically adjusting the activation and characteristics of exciters based on real-time vibration measurements. Rather than adding fixed passive damping components throughout the structure, the system changes operational parameters of selectively activated exciters to address specific vibration issues, reducing the need for extensive additional components.

Inventive Principle:

Principle #35Parameter changes

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 implementation of active damping elements effectively reduces vibration amplitudes and adapts to changing natural frequencies, minimizing structural damage and ensuring stable operation across wide speed ranges and varying AC frequencies.

Implementation Method 1

at least one active damping element providing forced vibrations that counteract structural vibrations of the electrodynamic machine

Methodology Applied

Scientific EffectForced vibrations: Driven Harmonic Oscillation

Implementation Method 2

the rotor assembly rotating within the stator assembly based on electromagnetic fields generated by the stator assembly and the rotor assembly

Methodology Applied

Scientific EffectElectromagnetic fields: Electromagnetic Propulsion

Implementation Method 3

at least one damping element reducing unbalanced forces of the rotor shaft caused by magnetic forces based upon the electromagnetic fields or caused by mechanical forces

Methodology Applied

Scientific EffectDamping: Damping

Data Source

PatentUS9906092B2Electrodynamic machines, and method for reducing vibration of an electrodynamic machine

Publication Date: 2018.02.27 INNOMOTICS LLC

AI summary

An electrodynamic machine includes a rotor assembly, a stator assembly defining an annular core receiving the rotor assembly, the rotor assembly rotating within the stator assembly based on electromagnetic fields generated by the stator assembly and the rotor assembly, a plurality of structural components mechanically supporting the rotor assembly and stator assembly, and an active damping element providing forced vibrations that counteract structural vibrations of the electrodynamic machine caused by magnetic forces based upon the electromagnetic fields or caused by mechanical forces based upon the plurality of structural components.