Spiral-Spring CVT for Automatic Torque-Adaptive Gear Ratio Control

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Solution Overview

Problem

Current continuously variable transmission systems for light transport vehicles, such as bicycles, require manual gear selection and lack an economical, simple, and automatic solution for adapting transmission ratios to varying load and terrain conditions.

Innovation Solution

A transmission system that uses an elastic potential energy storage unit, such as a spiral spring, to accumulate and release energy, controlling the transmission ratio between input and output shafts through a blocking and release device, allowing for automatic and continuous adjustment of the rotation speed and torque based on input and output requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If manual gear selection is used in continuously variable transmission systems, then the system structure can be simplified, but the automation level and adaptability to varying load conditions deteriorate

Engineering Contradiction:
Improveautomatic gear selectionVSAvoidtransmission system structure
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The transmission system automatically adjusts its own transmission ratio based on the torque requirements at the output shaft, without requiring external manual intervention. The elastic energy storage unit and blocking device work together to sense load conditions and autonomously vary the transmission ratio, making the system self-regulating and adaptive to changing terrain and load conditions.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If continuously variable transmission ratio is implemented, then the adaptability to different load conditions is improved, but the device complexity increases

Engineering Contradiction:
Improveadaptation to load and terrain conditionsVSAvoidtransmission system structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The transmission ratio is varied by changing the physical state of the elastic energy storage unit (winding/unwinding of the spring), which alters the torque characteristics of the system. By modifying the elastic potential energy storage parameter through rotational movement, the transmission continuously adapts to different load and terrain conditions without requiring complex mechanical gear changes.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If elastic potential energy storage unit is used for automatic transmission ratio variation, then the smoothness of power delivery is improved, but the device complexity and energy loss increase

Engineering Contradiction:
Improvesmoothness of power deliveryVSAvoidenergy transfer efficiency
Core Design Contradiction:
Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The transmission system dynamically adjusts the transmission ratio by allowing the elastic energy storage unit to wind and unwind in response to varying torque demands. This dynamic adjustment enables smooth transitions between different transmission states, eliminating the jerky power delivery associated with discrete gear changes while maintaining energy efficiency through the reversible elastic energy storage mechanism.

Inventive Principle:
Principle #15Dynamics

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

Enables automatic and continuous variation of transmission ratios without the need for manual gear selection, optimizing energy transfer and improving the smoothness of power delivery to the wheels, enhancing the riding experience by adapting to changing conditions.

Implementation Method 1

a rotational input shaft and a rotational output shaft linked by means of a system for accumulating and converting potential and kinetic energies

Methodology Applied
Scientific EffectElastic potential energy: Elasticity

Implementation Method 2

controlling the transmission ratio between input and output shafts through a blocking and release device, allowing for automatic and continuous adjustment of the rotation speed and torque

Methodology Applied
Scientific EffectTorque control: Torque

Data Source

PatentEP3156692B1Continuously variable automatic transmission
Publication Date: 2021.12.01 CARAMES JIMENEZ JOSE ANTONIO
  • EP3156692B1 patent drawingFigure 1
  • EP3156692B1 patent drawingFigure 2
  • EP3156692B1 patent drawingFigure 3

AI summary

The invention relates to a continuously variable automatic transmission that modifies the transmission ratio thereof by means of the accumulation and conversion of potential and kinetic energy. The transmission, which is functionally formed around an elastic potential energy accumulator device (6) with a controlled (7) output (2), has an input system (5) suitable for distributing the energy that is absorbed, and an output system (9) suitable for delivering the potential energy that has been absorbed and converting it into kinetic energy. The accumulator of elastic potential energy is formed around an elastic spiral spring, the inlet thereof being arranged so as to only allow the inflow of energy and the outlet thereof so as to control the energy delivery.