Foamed Undercord Drive Belts for Energy Efficiency and Durability

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Solution Overview

Problem

Existing automobile power transmission belts require significant energy to turn, leading to increased fuel consumption and emissions, and existing attempts to reduce bending stiffness often compromise durability and performance.

Innovation Solution

Incorporating a foamed undercord layer with a plurality of void spaces and optionally chopped fibers into the belt, which reduces bending stiffness without sacrificing durability or power transmission capability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the bending stiffness of the belt is decreased to reduce energy consumption, then energy efficiency is improved, but durability and power transmission capability are compromised

Engineering Contradiction:

Improveenergy consumptionVSAvoiddurability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The undercord layer is foamed to create a porous structure with void spaces distributed throughout its thickness. This porous structure reduces the bending stiffness of the belt while maintaining sufficient strength and durability through the strategic placement of void spaces that do not compromise the load-bearing capacity of the cord elements.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The belt employs a composite structure combining a foamed undercord layer with solid cord elements and cover layers. This composite approach allows the undercord to provide flexibility and reduced bending stiffness, while the cord elements and covers maintain structural integrity, durability, and power transmission capability.

Inventive Principle:

Principle #40Composite materials

2Use of energy by moving object

If the bending stiffness of the belt is decreased to improve fuel economy, then energy efficiency is improved, but power transmission capability is compromised

Engineering Contradiction:

Improvefuel consumptionVSAvoidpower transmission capability

Core Design Contradiction:

Use of energy by moving objectVSPower

Solution Approach 1:

The foamed undercord layer with controlled porosity reduces bending stiffness to lower the torque required to bend the belt during operation, thereby improving fuel economy. The porous structure is designed to maintain sufficient rigidity in the radial direction to ensure effective power transmission from the crankshaft to the camshaft.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The composite construction with solid cord elements embedded in the foamed undercord layer provides the necessary tensile strength and power transmission capability, while the foamed structure reduces bending resistance. This combination ensures both improved fuel economy and maintained power transmission effectiveness.

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

The foamed undercord layer significantly reduces the bending stiffness of the belt, thereby improving energy efficiency, reducing fuel consumption, and minimizing emissions while maintaining the belt's durability and performance.

Implementation Method 1

the undercord layer is foamed throughout the entire thickness of the undercord layer. Because the undercord layer is foamed, it includes a plurality of void spaces located throughout the thickness of the undercord layer

Methodology Applied

Scientific EffectFoaming: Foam

Implementation Method 2

applying heat and pressure to the sheet of uncrosslinked undercord to thereby cure and foam the sheet of undercord material

Methodology Applied

Scientific EffectCuring: Heat Treatment

Data Source

PatentUS12313145B2Drive belts including foamed undercord layers and methods of manufacturing the same

Publication Date: 2025.05.27 THE GATES CORP

AI summary

A drive belt includes a foamed undercord layer having void spaces located throughout the foamed undercord layer. The void spaces extend from a backing layer of the undercord layer to an exterior surface of the backing layer, and may include some void spaces at the exterior surface that are open to the external environment. The foamed undercord layer may exhibit a 20% reduction in specific gravity as compared to an unfoamed version of the undercord layer. The manufacturing process for making the foamed undercord layer can include incorporating foaming agent in the undercord layer such that the undercord layer both foams and cures when heat and pressure are applied to the undercord layer. The foamed drive belt incorporating the foamed undercord layer may exhibit reduced bending stiffness and improved energy efficiency.