Air-Driven Alternator for Electrostatic Spray Gun

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Solution Overview

Problem

Conventional electrostatic spray guns require high voltages (20,000 - 100 kV) and complex external power sources to generate an intense electrostatic field for efficient spraying, which can be cumbersome and inefficient.

Innovation Solution

An electrostatic spray gun with an air-driven turbine-powered alternator that generates electrical power internally, using a Neodymium magnet rotor and copper wire windings to produce a compact and efficient electromagnetic alternator, reducing size and weight by 40% and improving responsiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If an external power source is used to generate high voltage for the electrostatic field, then the required voltage level is achieved, but the device complexity and size increase

Engineering Contradiction:
Improvevoltage levelVSAvoidpower source complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent combines the power generation function directly into the spray gun by integrating a turbine and alternator assembly within the gun housing. This merging of functions eliminates the need for separate external power sources and voltage multipliers, reducing overall system complexity while maintaining the required high voltage output for electrostatic field generation

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spray gun becomes self-powered through the integration of a turbine driven by compressed air from the spray system itself. The alternator converts this mechanical energy into electrical energy to generate the high voltage needed for the electrostatic field, allowing the device to serve its own power needs without external intervention

Inventive Principle:
Principle #25Self-service

2Volume of moving object

If a compact alternator design is used, then the size and weight are reduced, but the ability to generate sufficient electrostatic field intensity may be compromised

Engineering Contradiction:
Improvealternator sizeVSAvoidelectrostatic field intensity
Core Design Contradiction:
Volume of moving objectVSPower

Solution Approach 1:

The patent achieves compact size while maintaining field intensity by changing key parameters of the alternator design: using a high-speed turbine (10,000-20,000 RPM), employing a voltage multiplier circuit to boost output voltage, and optimizing the alternator winding configuration. These parameter changes allow a small alternator to generate sufficient high voltage for the electrostatic field

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The high-speed rotating turbine and alternator create periodic electromagnetic induction at high frequency, which when combined with the voltage multiplier, generates the intense electrostatic field needed. The rapid rotational speed compensates for the small size by increasing the rate of magnetic flux change, thereby maintaining field intensity in a compact form

Inventive Principle:
Principle #19Periodic action

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 compact alternator design reduces overspray and improves operational efficiency by generating a strong electrostatic field with lower volume and weight requirements, enhancing the responsiveness and reliability of the spray gun.

Implementation Method 1

an air-driven turbine that drives an electromagnetic alternator

Methodology Applied
Scientific EffectTurbine: Turbine

Implementation Method 2

an air-driven turbine that drives an electromagnetic alternator

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

The charged particles are thereby attracted to the article to be sprayed

Methodology Applied
Scientific EffectElectrostatic force: Electrostatics

Data Source

PatentEP2903746B1Alternator for electrostatic spray gun
Publication Date: 2019.05.01 GRACO MINNESTOA INC
  • EP2903746B1 patent drawingFigure 1
  • EP2903746B1 patent drawingFigure 2
  • EP2903746B1 patent drawingFigure 3

AI summary

An alternator, such as for use in an electrostatic spray gun, comprises an alternator housing, a stator, a rotor, a shaft, a first bearing and a sheath. The stator is inserted into the alternator housing and has an inner diameter and an outer diameter. The rotor is disposed within the inner diameter of the stator. The shaft extends from the rotor and is rotatably supported by a first bearing. The sheath surrounds the outer diameter, supports the stator with respect to the alternator housing, and supports the bearing.