Self-Inflating Tire Valve with Peristaltic Pump

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Solution Overview

Problem

Tires naturally lose air pressure over time, requiring frequent driver intervention to maintain recommended pressure, which affects fuel economy, tire life, and vehicle handling performance.

Innovation Solution

A self-inflating tire assembly with a valve device that includes a pressure membrane and spring mechanism, allowing air to flow into the tire cavity when pressure drops, using a peristaltic pump assembly with check valves to prevent backflow and ensure efficient air distribution.

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 additional components such as pressure membranes, springs, and valve bodies

Engineering Contradiction:
Improveautomatic tire inflationVSAvoidvalve device structure
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The tire inflation system uses the tire's own rotation and road contact to drive the peristaltic pump, eliminating the need for external power sources or complex control systems. The pressure membrane automatically responds to pressure differential to open/close the channel, and check valves autonomously prevent backflow without requiring active control.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system employs pneumatic principles where the pressure membrane responds to pressure differential between the tire cavity and ambient air to automatically open or close the air channel. The peristaltic pump uses mechanical compression of the air passage by the tire footprint to move air, and check valves use pressure differential to prevent backflow.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Productivity

If the air passageway is allowed to substantially close near the tire footprint, then air can be effectively pumped into the tire cavity, but the passageway must be precisely positioned and dimensioned to ensure proper closing function

Engineering Contradiction:
Improveair pumping efficiencyVSAvoidair passageway positioning
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The air passageway is designed with non-uniform cross-sectional dimensions, being thicker at the inlet end and thinner at the outlet end. This local variation in geometry ensures that the passageway closes effectively at the desired location near the tire footprint while maintaining proper air flow characteristics throughout its length.

Inventive Principle:
Principle #3Local quality

3Productivity

If check valves are used to prevent backflow of air, then air distribution efficiency is improved, but the valve device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveair distribution efficiencyVSAvoidvalve device assembly
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

Both the inlet and outlet valve devices use identical check valve mechanisms with the same structural design. This standardization simplifies manufacturing and assembly, as the same component can be produced in volume and installed in both locations without requiring different precision levels or assembly procedures.

Inventive Principle:
Principle #33Homogeneity

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 without driver intervention, enhancing fuel efficiency, tire longevity, and vehicle performance by continuously inflating the tire as needed.

Implementation Method 1

a pressure membrane positioned to open or close the channel in response to a pressure differential between the tire cavity and the interior chamber of the valve body

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

a spring positioned to exert force upon the pressure membrane

Methodology Applied
Scientific EffectElastic force: Spring

Implementation Method 3

an air passageway having an inlet end and an outlet end and being operative to allow a portion of the air passageway near a tire footprint to substantially close the passageway

Methodology Applied
Scientific EffectPeristalsis: Peristalsis

Implementation Method 4

outlet check valves positioned in the air passageway outlet to prevent backflow of air from the tire cavity to the air passageway

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP2746072B1Compact valve system for self-inflating tire
Publication Date: 2019.03.27 THE GOODYEAR TIRE & RUBBER CO
  • EP2746072B1 patent drawingFigure 1
  • EP2746072B1 patent drawingFigure 2A
  • EP2746072B1 patent drawingFigure 2B

AI summary

A self-inflating tire assembly comprising a tire having a tire cavity, a first and second sidewall extending respectively from first and second tire bead regions to a tire tread region is disclosed. The tire has an air passageway, the air passageway having an inlet end and an outlet end and being operative to allow a portion of the air passageway near a tire footprint to substantially close the passageway. The outlet end of the air passageway is in fluid communication with the tire cavity. A valve device is connected to an end of the air passageway, the valve device including an insert mounted in the tire. A valve body is mounted within the valve insert. The valve body has an interior chamber, said interior chamber having a first hole in fluid communication with the end of the air passageway, and a channel in fluid communication with the ambient air. Also, alternative self-inflating tire assemblies are disclosed as well as valve devices for use with such tires.