Contactless Bicycle Dynamo Using Eddy Current Gearing
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Solution Overview
Problem
Existing bicycle dynamo systems face inefficiencies, significant braking effects, and weather dependence due to high contact pressure, and require additional magnets or metallic elements on the wheel, which are not suitable for sports wheels.
Innovation Solution
A contactless dynamo system using a conductive wheel rim as a counter element and a rotor element with permanent or electromagnets, where the rotor element induces eddy currents in the rim to generate a magnetic field, allowing for continuous relative movement and power generation without additional magnets or metallic components on the wheel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If additional magnets or magnetic rings are anchored in the spokes to achieve adequate power in contactless dynamos, then power generation capability is improved, but device complexity and suitability for sports wheels deteriorates
Solution Approach 1:
The invention extracts the magnetic components from the wheel structure by using a rotor element with magnets that rotates independently on a separate axis. The counter element utilizes the conductive wheel rim itself without adding magnets, thereby removing the complexity of anchoring additional magnets in spokes while maintaining power generation capability
Solution Approach 2:
The wheel rim serves multiple functions: it acts as both the structural component of the wheel and the conductive counter element for electromagnetic induction. This multi-functionality eliminates the need for separate magnetic components on the wheel, reducing device complexity while maintaining power generation
2Power
If friction wheel runs along the side panel or bearing surface of the tire to generate current, then power generation is achieved, but braking effect and efficiency worsen due to high contact pressure
Solution Approach 1:
The invention replaces the mechanical friction-based power generation system with an electromagnetic induction system. The rotor element with magnets induces eddy currents in the conductive counter element through electromagnetic interaction without mechanical contact, eliminating the braking effect while maintaining power generation capability
Solution Approach 2:
The invention introduces an electromagnetic field as an intermediary between the rotor element and counter element. This magnetic field mediates the energy transfer without requiring direct mechanical contact, thereby eliminating friction and associated braking effects while enabling power generation
3Power
If hub dynamos are integrated into the wheel hub with gear, then power and reliability are improved, but weight increases which is unacceptable for sports wheels
Solution Approach 1:
The invention extracts the heavy gear mechanism from the hub dynamo design by using a direct electromagnetic interaction between the rotor element and the wheel rim. The eddy current gearing formed between the conductive counter element and rotor element eliminates the need for mechanical gears, significantly reducing weight while maintaining adequate power output
Solution Approach 2:
The invention changes the operational parameters by using eddy current interaction instead of mechanical gear engagement. This parameter change allows for contactless power transmission with reduced weight, as the electromagnetic field can transmit torque without the mass of mechanical gears
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 system provides efficient, noiseless, and weather-independent power generation with reduced braking effect and weight, using existing wheel rims as transmission components, achieving higher torque and current yield with a simpler structure.
Implementation Method 1
the rotor element is designed to generate at least one magnetic field on the basis of an eddy current in the conductive counter element
Implementation Method 2
at least one coil, in the at least one winding of which a current can be induced by the magnet
Implementation Method 3
the rotor element is movable by magnetic interaction with the counter element
Implementation Method 4
with an eddy current gearing being formed
Data Source
AI summary
A device for contactless current generation, in particular bicycle dynamo, on a rotatable counter element, in particular wheel rim, with at least one movably mounted rotor element (2) having at least one magnet (3), and at least one coil (7), in the at least one winding of which a current can be induced by the magnet (3), which moves together with the rotor element (2), said current being usable to operate a consumer, wherein the rotor element (2) is movable by magnetic interaction with the counter element (1), characterized in that the rotor element (2) and the counter element (1) have different axial profiles, and, in an operative position, the rotor element (2) is designed to generate at least one magnetic field (6a, 6b) on the basis of an eddy current in the conductive counter element (1), which forms an uninterrupted circular path, in such a manner that, by means of continuous relative movement between the counter element (2) and rotor element (1), eddy current fields which are continuously opposed to one another and have oppositely polled magnetic fields (6a, 6b) to one another are induced in the counter element and the rotor element (2) is thus moved together with the counter element (1) with an eddy current gearing being formed. Furthermore, the invention relates to a vehicle lighting system and to a bicycle, each with a corresponding device for current generation.