V-Ribbed Belt Composite Layer for Lower Grinding Waste

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Solution Overview

Problem

Existing V-ribbed belts face issues with high grinding amounts, reduced durability, and appearance problems due to the use of nonwoven fabrics or thermoplastic resin layers on the rib tip surfaces, which affect bending properties and crack resistance.

Innovation Solution

A V-ribbed belt design featuring a compression rubber layer with a ground side surface and a non-ground bottom surface, incorporating a composite layer with a heat-resistant fiber assembly that is not melted during vulcanization, reducing the need for grinding and improving vulcanization efficiency, durability, and appearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the entirety of rib parts is ground to form V-grooves, then the rib shape is precisely formed, but the grinding amount (waste rubber) increases

Engineering Contradiction:
Improverib shape precisionVSAvoidgrinding waste
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The rib part is divided into two distinct zones: a ground side part for forming V-grooves and a non-ground bottom part for cost reduction. This segmentation allows selective grinding only where necessary for functionality while preserving material elsewhere.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different surface treatments are applied to different regions of the rib part: the side parts receive grinding treatment to create precise V-grooves for pulley engagement, while the bottom part remains unground to reduce waste. This local differentiation optimizes both precision and material efficiency.

Inventive Principle:
Principle #3Local quality

2Reliability

If nonwoven fabric is used on the rib tip surface to suppress abnormal sounds and wear, then noise and wear are reduced, but the belt becomes rigid and bending properties worsen

Engineering Contradiction:
Improvenoise suppression and wear resistanceVSAvoidbending properties
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The nonwoven fabric is completely removed from the rib tip surface. Instead of using fabric to suppress noise and wear, the invention achieves these functions through the ground side part structure and rubber composition formulation, extracting the problematic material while maintaining the desired performance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the durable but rigid nonwoven fabric with a ground rubber surface that provides adequate noise suppression and wear resistance without the rigidity problem. The ground surface serves as a sacrificial layer that maintains flexibility while providing the necessary friction control.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Ease of manufacture

If nonwoven fabric is used to secure releasability and breathability during vulcanization, then air bleeding is improved, but the appearance and durability are worsened

Engineering Contradiction:
Improvevulcanization breathabilityVSAvoiddurability and appearance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The nonwoven fabric is completely removed from the rib tip surface. The invention achieves adequate breathability during vulcanization through the ground rubber structure itself, eliminating the need for fabric while avoiding appearance and durability problems.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The ground rubber surface itself serves the dual function of providing breathability during vulcanization and maintaining appearance and durability in service. The porous ground structure naturally allows air bleeding while the rubber material provides the necessary surface properties.

Inventive Principle:
Principle #25Self-service

4Reliability

If thermoplastic resin layer is applied on the rib tip surface, then abnormal sounds and wear are suppressed, but bending properties worsen due to cramping

Engineering Contradiction:
Improvenoise and wear suppressionVSAvoidbending properties
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The thermoplastic resin layer is completely removed from the rib tip surface. The invention achieves noise and wear suppression through the ground rubber surface and optimized rubber composition, eliminating the cramping problem associated with thermoplastic layers.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the surface treatment parameter from applying a thermoplastic resin layer to using a ground rubber surface. This parameter change maintains noise and wear suppression while preserving bending flexibility, as the ground rubber does not cramp during bending.

Inventive Principle:
Principle #35Parameter changes

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 reduces grinding waste, enhances durability and heat resistance, and improves bending properties while maintaining excellent appearance by integrating the fiber assembly with the rubber composition, eliminating the need for adhesive treatments and reducing the risk of delamination.

Implementation Method 1

a fiber assembly containing a heat-resistant fiber which is not melted at a vulcanization temperature of a rubber composition

Methodology Applied
Scientific EffectHeat resistance:

Implementation Method 2

a vulcanizate of the rubber composition impregnated among fibers of the fiber assembly

Methodology Applied
Scientific EffectImpregnation: Absorption (physical)

Implementation Method 3

a side part of the compression rubber layer being a ground surface coming into contact with pulleys

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3358216B1V-ribbed belt and method for producing same
Publication Date: 2021.09.01 MITSUBOSHI BELTING LTD
  • EP3358216B1 patent drawingFigure 1~2
  • EP3358216B1 patent drawingFigure 3~4
  • EP3358216B1 patent drawingFigure 5

AI summary

The present invention pertains to a V-ribbed belt provided with a a core, a stretched layer, and a compressed rubber layer including a vulcanizate of a rubber composition, a side portion of the compressed rubber layer being a grinded surface that comes into contact with a pulley, and a bottom portion of the compressed rubber layer being a non-grinded surface that does not come into contact with the pulley wherein the surface of the bottom portion: includes heat-resistant fibers that do not melt at the vulcanization temperature of the rubber composition; and has a composite layer including a fiber assembly of which the weight is 25 g/m2 or less, and a vulcanizate of the rubber composition impregnated between the fibers of the fiber assembly.