Bicycle Hub Rotation Sensing Shielded From Foreign Matter
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Solution Overview
Problem
Existing hubs for human-powered vehicles lack reliable and cost-effective methods for detecting rotation of the sprocket support structure, which is essential for efficient power generation and component control, and are vulnerable to foreign matter interference.
Innovation Solution
The hub incorporates a rotation detection sensor, such as a magnetic or optical sensor, coupled with a coupling body made of non-magnetic or transparent materials to protect the sensor from foreign matter, and an electric power generator to produce power by rotation, with a circuit board and electronic controller for signal processing and component control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a rotation detection sensor is installed in the hub body to detect rotation of the sprocket support structure, then measurement precision is improved, but the sensor becomes vulnerable to foreign matter interference
Solution Approach 1:
A coupling body is introduced as an intermediary component between the rotation detection sensor and the sprocket support structure. This coupling body transmits rotational motion from the sprocket support structure to the sensor while protecting the sensor from foreign matter such as dirt and sand that could interfere with its operation.
Solution Approach 2:
The rotation detection sensor is disposed within the hub body, nested inside the protective structure of the hub. The coupling body extends from the sprocket support structure into the hub body, allowing the sensor to detect rotation internally without being directly exposed to external contaminants.
2Device complexity
If the rotation detection sensor is directly coupled to the sprocket support structure, then device complexity is reduced, but reliability deteriorates due to exposure to harsh environment
Solution Approach 1:
The coupling body serves as a mediator that connects the sprocket support structure to the rotation detection sensor. This intermediary component allows the sensor to be protected within the hub body while still accurately detecting the rotation of the sprocket support structure, thereby maintaining reliability without significantly increasing complexity.
3Object-affected harmful factors
If the hub body is made larger to accommodate protection structures for the sensor, then protection from foreign matter is improved, but weight of the hub increases
Solution Approach 1:
The hub body serves multiple functions: it provides structural support for the wheel, houses the rotation detection sensor, and acts as a protective enclosure against foreign matter. By integrating these functions into a single component rather than adding separate protective structures, the hub weight is minimized while still providing adequate protection.
Solution Approach 2:
The rotation detection sensor is nested within the existing hub body structure, utilizing the internal space of the hub rather than requiring additional external protective structures. This nested arrangement allows the sensor to be protected from foreign matter without significantly increasing the overall hub dimensions or weight.
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 configuration allows for reliable and accurate detection of rotation, protection from environmental interference, and efficient power generation for human-powered vehicles, enabling effective control of components and integration with electric systems.
Implementation Method 1
the rotation detection sensor includes a magnetic sensor, and the detected part includes a magnet
Implementation Method 2
the rotation detection sensor includes an optical sensor, and the detected part includes a reflective member
Implementation Method 3
an electric power generator disposed in the hub body, and configured to generate electric power by rotation of the hub body
Data Source
AI summary
A hub is provided for a human-powered vehicle. The hub comprises a hub axle, a hub body, a sprocket support structure, a detected part and a rotation detection sensor. The hub axle has a center axis. The hub body is rotatably disposed around the center axis. The sprocket support structure is rotatably disposed around the center axis to transmit a driving force to the hub body while rotating in a driving rotational direction around the center axis. The detected part is provided to the sprocket support structure. The rotation detection sensor is configured to detect the detected part to detect rotation of the sprocket support structure around the center axis and being disposed in the hub body.