Chainless E-Bike Speed Control for Natural Pedaling Feel

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Solution Overview

Problem

Conventional electric bicycles with chain drive systems have complex structures, especially in E-CARGO vehicles with three to four wheels, which complicates the drive system and increases the number of chains and gears.

Innovation Solution

A chainless drive system that converts pedal force into electricity and transmits it to the wheels without a chain, using a speed control device with a speed sensor, current sensor, wheel speed control unit, and pedal torque control unit to mimic the driving feel of a conventional bicycle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a chain drive system is used to connect pedals and drive wheels, then the driving force can be transmitted effectively, but the structure becomes complex especially in E-CARGO vehicles with three to four wheels

Engineering Contradiction:
Improvedriving force transmissionVSAvoiddrive system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the chain drive system from the E-CARGO vehicle, extracting the problematic component that caused structural complexity. The generator is directly coupled to the pedal assembly, eliminating the need for chains, gears, and other mechanical transmission components while maintaining effective driving force transmission through direct electrical power generation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical chain drive system with an electrical power generation system. The generator converts mechanical energy from pedal movement directly into electrical energy, which then powers the drive wheels through an electrical motor, substituting mechanical transmission with an electromechanical system that simplifies the overall drive train.

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

2Device complexity

If the chain is eliminated and pedal force is converted to electricity, then the drive system structure is simplified, but the driving feeling may differ from conventional bicycles

Engineering Contradiction:
Improvedrive system structureVSAvoiddriving feeling
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent incorporates a control system that provides feedback to maintain the desired driving feeling. Sensors detect pedal input and vehicle operation conditions, and the controller adjusts generator torque and motor assistance levels to replicate the natural cycling experience while maintaining the simplified chainless structure.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically adjusts operational parameters such as generator torque, motor assistance level, and power distribution to maintain the desired driving feeling. By changing these parameters in real-time based on sensor input, the system replicates the natural progression of pedal effort and vehicle response that cyclists expect.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If multiple chains and gears are used in E-CARGO vehicles, then the drive system can handle the complexity of three to four wheel configurations, but the number of components increases

Engineering Contradiction:
Improveapplicability to E-CARGO configurationsVSAvoidnumber of chains and gears
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent creates a universal chainless drive system that can be applied to E-CARGO vehicles with two, three, or four wheels without requiring different chain and gear configurations. The electrical power generation and transmission system provides a single, adaptable architecture that works across all vehicle configurations, eliminating the need for multiple mechanical transmission components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 chainless drive system simplifies the structure, allowing it to be applied to various small vehicles with three to four wheels while providing a driving experience similar to conventional bicycles, and meets electric bicycle regulations.

Implementation Method 1

a driving force of the pedal is converted into electricity, and the electricity is transmitted to the wheels without the chain

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4155181B1Apparatus for controlling speed of electric bicycle and method therefor
Publication Date: 2025.10.22 HL MANDO CORP
  • EP4155181B1 patent drawingFigure 1
  • EP4155181B1 patent drawingFigure 2
  • EP4155181B1 patent drawingFigure 3

AI summary

The present invention relates to electric bicycle speed control device and method. According to the present invention, a torque of a motor for driving a wheel is controlled so that a speed of a pedal driven by a user follows a speed of the wheel, and a torque of the pedal is also controlled by applying an assist level according to the torque of the motor. Therefore, even in an electric bicycle with a chain, it is possible to feel a feeling of the pedal like a bicycle with a chain, and it is possible to adjust the force applied to the pedal according to the assist level.