Linear Bicycle Drive Assembly Without Chain or Chainring
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Solution Overview
Problem
Conventional bicycle pedal drive systems are inefficient due to circular leg motion that reduces power output and awkward leg movements, and they often require heavy, bulky motorized units for supplementation.
Innovation Solution
A drive system that converts linear pedal motion into rear wheel rotation without chains or chainrings, allowing riders to choose pedal stroke length and incorporating a fluid drive system for energy storage and release, which reduces weight and eliminates the need for batteries and motors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional circular pedal motion is used, then the bicycle can be operated with simple structure, but power transfer efficiency deteriorates due to leg position constraints
Solution Approach 1:
The patent inverts the conventional rotary pedal motion into linear reciprocating motion. The pedal moves in a straight line back and forth, allowing the rider's leg to maintain a more advantageous extended position throughout the stroke, thereby improving power transfer efficiency while eliminating the need for complex chain and sprocket mechanisms.
Solution Approach 2:
The invention transitions from two-dimensional circular motion to one-dimensional linear motion. By constraining the pedal to move along a straight line rather than following a circular path, the system simplifies the mechanical configuration and allows for more effective muscle utilization during the pedaling stroke.
2Weight of moving object
If conventional chain drive system is used, then the drive mechanism is simple, but weight increases due to chain and chainring components
Solution Approach 1:
The patent extracts and eliminates the chain and chainring components from the bicycle drive system. By using a direct linear reciprocating pedal mechanism that connects the rider's input directly to the wheel propulsion, the system removes unnecessary intermediate components, thereby reducing overall bicycle weight while maintaining functional simplicity.
Solution Approach 2:
The invention merges the functions of the pedal, crank mechanism, and chain drive into a single integrated linear reciprocating system. This consolidation eliminates multiple separate components and their associated weights, while the simplified mechanism remains easy to operate and maintain.
3Power
If motorized drive units are added to supplement pedal drive, then power output increases, but weight and complexity increase significantly
Solution Approach 1:
The patent enables the bicycle to be self-sufficient through optimized human-powered linear reciprocating motion. By improving the mechanical efficiency of the pedal-to-wheel power transfer and allowing the rider to maintain more advantageous leg positions throughout the stroke, the system maximizes human power output without requiring external motorized assistance, thereby avoiding the weight and complexity penalties of motorized systems.
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
This system enhances power transfer efficiency, reduces weight, and provides adjustable pedaling for terrain demands, while eliminating the need for complex motorized components, resulting in a more efficient and lightweight bicycle design.
Implementation Method 1
a fluid drive system arranged to compress and store fluid (e.g., air) inside the frame
Implementation Method 2
The interaction between the drive assembly and the at least one drive shaft is such that the linear or downward movement of the drive assembly causes the at least one drive shaft to rotate
Data Source
AI summary
A bicycle includes a frame having a seat tube, a rear wheel including a drive plate, and a drive system configured to drive rotation of the rear wheel. The drive system includes at least one shaft operably extending in a direction between the seat tube and the rear wheel and arranged to interact with the drive plate. A pair of drive assemblies are located near or at least in part inside the seat tube and are arranged to operably interact with the drive shaft. The at least one drive shaft converts linear motion of the drive assemblies into rotation of the rear wheel without a chain or chainring.