Airless Tire Structure for Static Discharge and High-Speed Durability

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Solution Overview

Problem

Existing airless tires face challenges in maintaining high-speed durability while effectively eliminating static electricity from vehicles.

Innovation Solution

The airless tire design incorporates an annular tread portion with a conductive ground-contact surface, a resin or elastomer-based spoke and inner circumferential portions containing an antistatic agent, which connects the tread to a conductive wheel, allowing for static electricity discharge to the road surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional airless tires are designed to eliminate static electricity, then static electricity elimination function is improved, but high-speed durability deteriorates

Engineering Contradiction:
Improvestatic electricity eliminationVSAvoidhigh-speed durability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies local quality by differentiating the material composition of different tire portions. The tread portion uses a conductive composition with specific antistatic agents for static electricity elimination, while the inner circumferential portion uses a different composition optimized for durability and wheel contact. This localized material differentiation allows each portion to perform its specific function optimally without compromising overall performance.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs composite materials by combining base polymers with conductive fillers (carbon black, metal particles) and antistatic agents in specific ratios. The first composition includes polymer A (50-90 parts), polymer B (10-50 parts), conductive filler (1-20 parts), and antistatic agent (0.1-5 parts). This composite structure provides both the static electricity elimination function and the mechanical durability required for high-speed operation.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If antistatic agent is added to resin or elastomer, then static electricity elimination function is improved, but physical properties of the base material deteriorate

Engineering Contradiction:
Improvestatic electricity eliminationVSAvoidphysical properties of resin or elastomer
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent applies parameter changes by optimizing the amount of antistatic agent within a specific range (0.1-5 parts per 100 parts of polymer). This controlled parameter adjustment ensures sufficient static electricity elimination while preventing excessive antistatic agent content that would degrade the physical properties of the base polymer. The patent also adjusts the ratio of different polymers and conductive fillers to maintain structural integrity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials to balance antistatic function and mechanical strength. By combining base polymers with controlled amounts of conductive fillers and antistatic agents, the composition achieves both electrical conductivity for static elimination and adequate mechanical properties. The synergistic interaction between components ensures that the antistatic function is achieved without significant compromise to the base material's strength and durability.

Inventive Principle:
Principle #40Composite materials

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

This configuration enables the tire to maintain high-speed durability while effectively eliminating static electricity from vehicles, with the antistatic agent blended in optimal amounts to prevent physical property degradation and ensure long-term antistatic functionality.

Implementation Method 1

the second portion, the spoke portion, and the inner circumferential portion are formed from a resin or elastomer, the resin or elastomer contains an antistatic agent

Methodology Applied
Scientific EffectElectrical Conduction: Conduction (electrical)

Data Source

PatentEP4344901B1Airless tire
Publication Date: 2025.06.11 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4344901B1 patent drawingFigure 1
  • EP4344901B1 patent drawingFigure 2
  • EP4344901B1 patent drawingFigure 3

AI summary

It is possible to maintain high-speed durability while having a function of eliminating static electricity of a vehicle. An airless tire 1 includes a tread portion 2, an inner circumferential portion 3 which comes into contact with a wheel 5 having conductivity, and a spoke portion 4 which connects the tread portion 2 and the inner circumferential portion 3. The tread portion 2 includes a first portion 2A having conductivity, and a second portion 2B in contact with the first portion 2A. The second portion 2B, the spoke portion 4, and the inner circumferential portion 3 are formed from a resin or elastomer. The resin or elastomer contains an antistatic agent. The antistatic agent is a polymer-based antistatic agent or surfactant-based antistatic agent. The antistatic agent is blended in an amount of 0.5 to 20% by mass per 100% by mass of a base component of the resin or elastomer.