Curved-Rib Belt Geometry for Low-Wear Pulley Deflection

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Solution Overview

Problem

Conventional V-belts experience jamming and high friction when wrapped around pulleys, leading to increased wear and noise, and require a large pulley diameter to reduce friction, which compromises compactness and force transmission capacity.

Innovation Solution

A belt design featuring trapezoidal ribs with inwardly curved flanks and support sides, allowing the material to spread and reduce clamping effect, thereby minimizing friction and wear, and enabling deflection with lower noise levels without the need for large pulley diameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the belt is deflected by a conventional pulley with flat contact surfaces, then a frictional connection is created to transmit drive forces, but high alternating forces compress the belt material causing the V-belt to spread transversely resulting in jamming, increased wear, and noise

Engineering Contradiction:
Improvedrive force transmissionVSAvoidwear and noise
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent applies curvature to the contact surfaces by providing inwardly curved flanks and inwardly curved bearing surfaces on the ribs of the belt. This curved geometry allows the belt material to spread inward when compressed by the pulley, preventing transverse spreading and jamming while maintaining effective force transmission through the curved contact interface.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Object-generated harmful factors

If a large gap between the flanks of the belt and the flanges of the pulley is provided to reduce friction, then belt wear and noise are reduced, but the device becomes less compact and requires a larger installation space

Engineering Contradiction:
Improvefriction and wearVSAvoidinstallation space
Core Design Contradiction:
Object-generated harmful factorsVSVolume of moving object

Solution Approach 1:

The curved flanks and bearing surfaces enable the belt to maintain compact dimensions while reducing friction. The inward curvature allows material to spread during operation without requiring excessive gap space, achieving low friction and wear within a compact form factor.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Object-generated harmful factors

If a large gap between the belt and pulley is provided to reduce clamping effect, then friction is reduced, but the contact area becomes smaller reducing the force absorption capacity

Engineering Contradiction:
ImprovefrictionVSAvoidforce absorption capacity
Core Design Contradiction:
Object-generated harmful factorsVSForce

Solution Approach 1:

The inwardly curved bearing surfaces maintain adequate contact area with the pulley even when gaps are minimized. The curvature geometry ensures that the contact region remains sufficiently large to absorb high forces while the curved flanks prevent excessive clamping and friction.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 belt design significantly reduces wear and noise while maintaining high tensile force transmission capabilities, achieving a compact and efficient belt-pulley interaction.

Implementation Method 1

These high forces compress the belt material, causing the V-belt to spread transversely to its longitudinal direction in the area where it wraps around the drive pulley

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

the rib material itself can compress, pressing it towards the bearing surface

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

This would have the advantage of allowing the belt to be deflected with particularly low friction

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 4

creating a frictional connection that is desirable to ensure the transmission of drive forces to the V-belt

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3717796B1Belt and belt drive
Publication Date: 2021.12.01 CONTITECH ANTRIEBSSYSTEME GMBH
  • EP3717796B1 patent drawingFigure 1~2
  • EP3717796B1 patent drawingFigure 3~4
  • EP3717796B1 patent drawingFigure 5~6

AI summary

The present invention relates to a belt (2), having: at least one rib (4) formed in the belt longitudinal direction L, wherein each rib (4) has a trapezoidal cross-section (6) and each rib (4) therefore has a contact side (8) and two flanks (10) extending from the contact side (8), characterised in that each flank (10) is curved inwardly and/or each contact side (8) is curved inwardly. The invention also relates to a belt drive having a belt (2) of this kind and at least one belt pulley.