Concentric Rotor Bicycle Propulsion System
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric bicycle conversion systems require complex installations, necessitate removal of wheels, and lack efficient torque modulation, making them inconvenient for rapid conversion between manual and electric modes.
Innovation Solution
A concentric rotor assembly and chassis assembly system that transiently engages with a bicycle sprocket, allowing for rapid installation and removal without tools, and includes a sensor-activated motor control for dynamic torque adjustment based on chain tension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If existing electric bicycle conversion systems are used, then electric propulsion function is achieved, but installation complexity increases and conversion time extends
Solution Approach 1:
The system is divided into modular components: a concentric rotor assembly that engages with the sprocket, a chassis assembly with motor housing, and a drive mechanism. This segmentation allows independent installation of each module, simplifying the overall installation process and reducing system complexity.
Solution Approach 2:
The concentric rotor assembly is designed to nest around the existing bicycle sprocket, with the rotor containing the drive mechanism and the chassis assembly containing the motor. This nested configuration eliminates the need for separate mounting brackets and reduces installation steps while maintaining compact form factor.
2Ease of operation
If existing electric bicycle conversion systems are used, then electric propulsion function is achieved, but wheel removal is required
Solution Approach 1:
The drive mechanism is extracted from the traditional hub-based configuration and repositioned to engage directly with the sprocket through the concentric rotor assembly. This extraction eliminates the need to remove wheels for installation, as the system attaches to the drivetrain components that remain on the bicycle.
Solution Approach 2:
The concentric rotor assembly serves multiple functions: it acts as the motor output interface, engages with the sprocket teeth for power transmission, and provides structural mounting for the drive mechanism. This multi-functionality eliminates the need for additional wheel removal or specialized mounting procedures.
3Power
If existing electric bicycle conversion systems are used, then propulsion assistance is provided, but torque modulation efficiency decreases
Solution Approach 1:
The system incorporates a sensor that detects chain tension and provides real-time feedback to the motor controller. This feedback loop enables dynamic torque modulation where the motor adjusts its output based on the actual load conditions, improving propulsion efficiency without requiring complex mechanical torque adjustment mechanisms.
Solution Approach 2:
Traditional mechanical torque modulation mechanisms (such as variable gear ratios or clutch systems) are replaced with electronic torque control through the motor controller. This substitution simplifies the control mechanism while maintaining or improving torque modulation efficiency through precise electronic actuation.
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 seamless and efficient conversion between manual and electric bicycle modes with rapid installation and removal, providing effective pedal assistance while minimizing mechanical interference and operational complexity.
Implementation Method 1
a motor configured to rotate the concentric rotor assembly about a center axis of the circular outer drive surface via the drive subassembly, the motor causing rotation of the first bicycle sprocket
Data Source
AI summary
A bicycle propulsion system including a concentric rotor assembly and a chassis assembly. The concentric rotor assembly: defines an outer drive surface; defines an inner retention surface; includes a set of sprocket brackets arranged about the inner retention surface of the concentric rotor assembly and configured to engage with teeth of a bicycle sprocket; and is configured to engage around the bicycle sprocket, wherein a center axis of the outer drive surface is concentric with a rotational axis of the bicycle sprocket. The chassis assembly: is configured to secure to a stay of the bicycle; includes a retention subassembly configured to translationally constrain the concentric rotor assembly relative to the chassis assembly; includes a drive subassembly configured to engage the outer drive surface of the concentric rotor assembly; and includes a motor configured to rotate the concentric rotor assembly via the drive subassembly.