Self-Inflating Tire Inlet Control Valve

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Solution Overview

Problem

Tire pressure naturally decreases over time due to air diffusion, leading to reduced fuel economy, tire life, and vehicle handling performance, and existing Tire Pressure Monitoring Systems require driver intervention for re-inflation.

Innovation Solution

A self-inflating tire assembly with a peristaltic pump mechanism and pressure regulator, featuring a flexible air passageway and a regulator device with a pressure membrane that opens and closes to control air flow, allowing outside air to enter and maintain optimal tire pressure without driver intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a self-inflating mechanism is incorporated into the tire, then driver intervention is eliminated and tire pressure is automatically maintained, but device complexity increases due to the addition of pump mechanism and control valves

Engineering Contradiction:
Improveautomatic tire inflationVSAvoidpump mechanism and valve system
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The tire system performs self-inflation by utilizing the rotation of the tire itself to drive a peristaltic pump mechanism. The flexible air passageway is compressed and expanded by the rotating tire structure, automatically drawing air in and pumping it into the tire cavity without requiring external power sources or complex electronic controls

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system employs pneumatic principles through the use of flexible air passageways that utilize pressure differentials created during tire rotation. The peristaltic action of the flexible passages creates automatic air intake and delivery to the tire cavity, using the tire's own motion to generate the necessary pneumatic forces

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Reliability

If a regulator device with pressure membrane is added to control air flow, then tire pressure is precisely maintained, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvetire pressure maintenanceVSAvoidregulator device assembly
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The regulator device replaces complex electronic pressure control systems with a simple mechanical membrane-based mechanism. The flexible membrane responds directly to pressure differential between the tire cavity and atmosphere, opening or closing the air passageway automatically based on tire pressure conditions without requiring sensors or electronic actuators

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

Solution Approach 2:

The regulator device utilizes a flexible pressure membrane that deforms in response to tire pressure changes. This thin film element serves as both the sensing element and the control element, opening or closing the air passageway through its elastic deformation, thereby simplifying the regulator structure while maintaining reliable pressure control

Inventive Principle:
Principle #30Flexible shells and thin films

3Extent of automation

If flexible air passageway material is used to enable opening and closing during rotation, then automatic inflation is achieved, but manufacturing precision requirements increase

Engineering Contradiction:
Improverotation-driven air intakeVSAvoidflexible passageway geometry
Core Design Contradiction:
Extent of automationVSManufacturing precision

Solution Approach 1:

The air passageway is designed as a flexible, dynamic structure rather than a rigid component. The passageway's geometry changes during tire rotation, utilizing the dynamic compression and expansion of the flexible material to control air flow timing and direction, thereby reducing the need for high-precision static geometric tolerances

Inventive Principle:
Principle #15Dynamics

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 system automatically maintains optimal tire pressure, enhancing fuel efficiency, tire longevity, and vehicle handling by continuously inflating the tire as needed, reducing the need for frequent driver adjustments.

Implementation Method 1

a pump mechanism and pressure regulator for such tires

Methodology Applied
Scientific EffectPeristalsis: Peristalsis

Implementation Method 2

the flexible material is operative to open and close when the tire rotates

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP2886372B1Self-inflating tire with inlet control valve
Publication Date: 2016.09.14 THE GOODYEAR TIRE & RUBBER CO
  • EP2886372B1 patent drawingFigure 1
  • EP2886372B1 patent drawingFigure 2
  • EP2886372B1 patent drawingFigure 3

AI summary

A self-inflating tire (12) comprising a tire cavity (40), first and second sidewalls (15) extending respectively from first and second tire bead regions to a tire tread region, and an air passageway (43) having an inlet end (42) and an outlet end (44) is disclosed. The air passageway (43) is composed of or established by a flexible material and is operative to open and close when the tire (12) rotates in contact with a contact area under its standard load and normal pressure. The tire (12) further comprises a regulator device or inlet control valve assembly (300). The regulator device or inlet control valve assembly (300) includes a housing (310) or regulator body. The housing (310) or regulator body has an interior chamber (320). A pressure membrane (550) is mounted in the interior chamber (320) and positioned to open and close an outlet port (330) provided in the interior chamber (320). The pressure membrane (550) is in fluid communication with the tire cavity pressure. The outlet port (330) of the regulator device or inlet control valve assembly (300) is in fluid communication with the inlet end (42) of the air passageway (43). The interior chamber (320) is in fluid communication with an outside air supply. The outlet end (44) of the air passageway (43) is in fluid communication with the tire cavity (40).