Conductive Plastic Vapor Pump for Fuel Ignition Prevention

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Solution Overview

Problem

Existing automotive vapor pumps face issues with electrostatic charging of the pumping wheel, leading to the danger of sparking and fuel vapor ignition, as well as corrosion damage due to water content in the fuel vapor.

Innovation Solution

A vapor pump design featuring a pumping wheel made from electrically conductive plastic material, a conductive rotor shaft, and an electrically conductive bearing arrangement grounded via a conductor, along with a sealed motor stator and electronic components within a solid plastic motor housing, prevents electrostatic charging and corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the pumping wheel is made from non-conductive material, then manufacturing cost is reduced, but electrostatic charging occurs leading to sparking and fuel vapor ignition danger

Engineering Contradiction:

Improvemanufacturing costVSAvoidelectrostatic charging and ignition danger

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The pumping wheel material is changed from non-conductive to conductive plastic material, fundamentally altering the electrical property parameter to prevent electrostatic charging while maintaining the benefits of plastic material for corrosion resistance and cost-effectiveness

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The pumping wheel is made from composite plastic material that incorporates conductive properties, combining the advantages of plastic (corrosion resistance, low cost) with electrical conductivity to eliminate sparking hazards

Inventive Principle:

Principle #40Composite materials

2Reliability

If the pumping wheel is made from metal material to ensure conductivity, then electrostatic discharge is prevented, but corrosion damage occurs due to water content in fuel vapor

Engineering Contradiction:

Improveelectrostatic discharge preventionVSAvoidcorrosion damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The pumping wheel uses conductive plastic material that combines the corrosion resistance of plastics with the electrical conductivity needed to prevent electrostatic charging, eliminating the need for metal materials that would corrode in the presence of water-containing fuel vapor

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The material is selected to have both conductive properties and corrosion resistance, changing the material parameter from traditional metal or non-conductive plastic to a specialized conductive plastic that resists corrosion from fuel vapor moisture

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If the motor components are exposed to fuel vapor, then the structure is simplified, but corrosion damage and electrostatic charging occur

Engineering Contradiction:

Improvestructural complexityVSAvoidcorrosion damage and electrostatic charging

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The pump is divided into separate zones: the motor housing and electronics are isolated from the pump chamber containing fuel vapor. This segmentation protects sensitive components while allowing the conductive pumping wheel to handle vapor processing

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The conductive pumping wheel acts as an intermediary that interfaces between the fuel vapor environment and the protected motor components, preventing direct contact between corrosive vapor and sensitive electronics while maintaining necessary functionality

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

The solution effectively prevents fuel vapor ignition and corrosion damage, ensuring safe and reliable operation of the vapor pump by grounding the pumping wheel and sealing the motor components from fuel vapor.

Implementation Method 1

an electrically conductive bearing arrangement which is directly or indirectly electrically connected with the contact plug via a conductor

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

a pumping wheel arranged in the pump chamber and mounted on the rotor shaft so as to rotate therewith; The pumping wheel is configured to pump the fuel vapor from the inlet opening to the outlet opening

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentUS11319966B2Motor vehicle auxiliary power unit vacuum pump

Publication Date: 2022.05.03 PIERBURG PUMP TECH

AI summary

A vapor pump for an automotive application includes a housing group with a pump housing having a pump chamber, an inlet opening and an outlet opening, and a motor housing having a motor chamber; a rotor shaft made from an electrically conductive material; a pumping wheel made of an electrically conductive plastic material arranged in the pump chamber and mounted on the rotor shaft to rotate therewith to pump the fuel vapor from the inlet opening to the outlet opening; a drive motor arranged in the motor chamber which includes a motor stator, a motor rotor and a motor control unit; a contact plug which electrically connects the motor control unit; and an electrically conductive bearing arrangement which is connected with the contact plug via a conductor. The motor rotor is connected with the rotor shaft to rotate therewith. The electrically conductive bearing arrangement rotatably supports the rotor shaft.