Rotational Power Transmission Mechanism With Self-Locking Wedging Elements

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Solution Overview

Problem

Existing mechanical power transmission mechanisms, such as CVT systems, face inefficiencies due to high pinching forces required to prevent slipping and energy consumption in compressing springs, as well as parasitic frictions from unnecessary chain tension, limiting torque transmission and energy efficiency.

Innovation Solution

A rotational power transmission mechanism utilizing a closed-loop link with self-locking means, including rigid wedging elements that securely engage with rotating elements via tangential gripping surfaces, allowing for continuous variation of the transmission ratio and high torque transmission while minimizing energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If high pinching force is applied to prevent chain slipping, then torque transmission is improved, but energy efficiency deteriorates due to spring compression and friction losses

Engineering Contradiction:
Improvetorque transmissionVSAvoidenergy efficiency
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

The wedging element automatically secures the link to the rotating element through self-locking action when torque is transmitted, and automatically releases when the link leaves the active portion. The system uses the transmitted torque itself to create the securing force, eliminating the need for external spring compression or continuous tensioning forces.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention replaces the elastic spring-based pinching mechanism with a rigid wedging element that uses direct mechanical contact and friction on tangential surfaces. This substitution eliminates the energy-consuming compression and relaxation cycles of elastic materials while maintaining secure torque transmission.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Force

If basic tension is applied to the chain to maintain adhesion, then torque transmission is improved, but energy efficiency deteriorates due to parasitic frictions

Engineering Contradiction:
Improveadhesion forceVSAvoidparasitic friction
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

The wedging element generates the necessary securing force automatically through the transmitted torque, eliminating the need for continuous basic tension in the link. The friction force is activated only when needed for torque transmission, not continuously as in conventional systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the orientation of the bearing surface to be tangential (parallel) to the link portion, allowing the wedging element to engage through friction without requiring the link to be under continuous tension. This parameter change enables adhesion force to be generated on-demand rather than through continuous tensioning.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If elastic supports are used to adapt pitch between meshing members, then adaptability is improved, but energy efficiency deteriorates due to compression and relaxation cycles

Engineering Contradiction:
Improvepitch adaptationVSAvoidenergy consumption
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The invention replaces elastic deformable supports with rigid bodies that maintain their shape. The adaptability function is achieved through the movement and repositioning of rigid wedging elements rather than through elastic deformation, eliminating energy loss from compression and relaxation cycles.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If multiple self-locking means are distributed along the drive circle, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvesecuring reliabilityVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system divides the continuous drive circle into discrete active portions where self-locking means are distributed. Each self-locking means is a simple rigid wedging element that engages independently, providing reliable torque transmission through multiple contact points without requiring complex interconnected mechanisms.

Inventive Principle:
Principle #1Segmentation

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 mechanism achieves improved energy efficiency and high torque transmission by using self-locking means that secure the link to rotating elements with proportional bearing forces, eliminating the need for slack tension and reducing frictional losses.

Implementation Method 1

at least one of the first or second bearing surface is a tangential gripping surface which is parallel to the longitudinal direction of the link portion against which the wedging element bears

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the bearing force on the first and second bearing surfaces is proportional to the torque transmitted so as to maintain the immobilization

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP2734748B1Mechanism and method for transmitting power of rotation
Publication Date: 2016.09.28 CLOPET CYRIL
  • EP2734748B1 patent drawingFigure 1
  • EP2734748B1 patent drawingFigure 2
  • EP2734748B1 patent drawingFigure 3a~3d

AI summary

Mechanism for transmitting power of rotation comprising a link (5) extending in a closed loop (5a) and consisting of a succession of portions each having a longitudinal direction tangential to the closed loop. Means of temporary attachment comprise a plurality of self-locking means (12, 13) distributed at least along an active portion (6a) of a first drive circle (6), the self-locking means comprising at least one rigid wedging element (19) pressing simultaneously both on a first bearing surface belonging to the first rotary element (1) and on a second bearing surface belonging to a link portion (5) facing the wedging element. The first and second bearing surfaces are arranged in such a way that at least one wedging element (19) of the active portion (6a) of the first drive circle is braced between the first and second bearing surfaces and is able to unlock itself when the corresponding self-locking means leaves the active portion (6a). One of the first or second bearing surfaces is a tangential grip surface parallel to the longitudinal direction of the portion of link against which the wedging element is bearing.