Rotary Atomizer Motor Parameter Analysis for Coating Error Detection

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Solution Overview

Problem

Existing rotary atomizers face issues with coating errors due to inertia in pneumatic drive systems, unreliable signal transmission through optical waveguides, and undetected process errors, particularly in electrostatic coating processes requiring high voltages, which are not adequately addressed by replacing air turbines with electric drives without additional measures.

Innovation Solution

Employing an electric drive motor for the bell cup of a rotary atomizer, allowing for rapid and reliable detection of defects through motor characteristic evaluation, enabling dynamic control of coating process parameters without external sensors, and using a transformer arrangement for high-voltage isolation and signal transmission in electrostatic systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an electric drive motor is used for the bell cup instead of a pneumatic turbine, then the detection speed and reliability of coating errors is improved, but the device complexity increases due to high-voltage isolation requirements

Engineering Contradiction:
Improvedetection reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A transformer arrangement with high-voltage isolation serves as an intermediary device, enabling signal transmission between the high-voltage motor area and the control system while maintaining electrical isolation. This resolves the contradiction by allowing reliable error detection through the motor while managing the complexity through a dedicated isolation mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system continuously monitors motor characteristics (current, torque, speed) and feeds this information back to the control system for real-time analysis. This feedback mechanism enables rapid detection of coating errors by comparing actual motor behavior against expected parameters, improving reliability while using the existing motor as the sensing element.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If optical waveguides are used for signal transmission in painting robots, then the measurement capability is improved, but the service life is reduced due to constant bending movements

Engineering Contradiction:
Improvemeasurement capabilityVSAvoidservice life
Core Design Contradiction:
Measurement precisionVSDuration of action of stationary object

Solution Approach 1:

The invention extracts the signal transmission function from the mechanical robot arm by using the motor's electrical signals directly for error detection. Instead of relying on optical waveguides that must be physically installed in the moving robot arm, the system uses the motor's own operational characteristics as the measurement source, eliminating the fragile optical components while maintaining measurement capability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Manufacturing precision

If the speed of the bell cup is kept constant by controlling drive air, then the manufacturing precision is improved, but the response time to coating errors is increased due to system inertia

Engineering Contradiction:
Improvecoating precisionVSAvoidresponse time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The system uses continuous feedback from motor current and torque measurements to detect coating errors in real-time. When an error is detected (such as a bell cup collision or incorrect bell cup installation), the control system can immediately respond by adjusting the drive air or stopping the motor, significantly reducing the response time compared to traditional pneumatic control alone.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention replaces the purely mechanical pneumatic control system with an electromechanical system that uses electric motor characteristics for error detection. This substitution enables faster response times because electrical signal processing and motor control are inherently faster than pneumatic system response, while still maintaining coating precision through controlled bell cup rotation.

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

4Manufacturing precision

If high voltage is applied to the rotary atomizer for electrostatic charging, then the coating quality is improved, but the safety risks and device complexity increase

Engineering Contradiction:
Improvecoating qualityVSAvoidsafety risks
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The transformer arrangement acts as a high-voltage intermediary that provides galvanic isolation between the high-voltage electrostatic charging system and the control electronics. This isolation protects the control system and operators from high-voltage risks while maintaining the necessary electrostatic charging for high-quality coating application.

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

Enables quick and precise detection and correction of coating errors, improved process control, and enhanced quality in coating applications by analyzing motor parameters such as torque, power, and speed, reducing the risk of defects and wear, particularly in high-speed and electrostatic rotary atomizers.

Implementation Method 1

Instead of a pneumatic drive turbine, an electric drive motor, in particular a synchronous motor, is used for driving the bell cup

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

a transformer arrangement for high-voltage isolation and signal transmission in electrostatic systems

Methodology Applied
Scientific EffectElectromagnetic transformation: Electromagnetic Induction

Implementation Method 3

In atomizers that operate with direct charging of the coating material, the electrically conductive part of the atomizer is usually subjected to high voltage so that the coating material can be charged

Methodology Applied
Scientific EffectElectrostatic charging: Electrostatic Induction

Data Source

PatentEP2178648B2Method for process diagnosis and rotary atomizer arrangement
Publication Date: 2019.10.16 DUERR SYST AG
  • EP2178648B2 patent drawingFigure 1~2
  • EP2178648B2 patent drawingFigure 3

AI summary

During the coating of work pieces by a rotary atomizer of which the bell plate is driven by an electric motor (M) and for the detection of errors in the spraying process and/or the drive system of the bell plate, corresponding parameters are analyzed by evaluation of typical values of the drive motor (M) such as current, output, torque, etc.