Pedal Force Sensing Mechanism With Slip-Ring Signal Transmission
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Solution Overview
Problem
Existing electric-assist bicycles struggle to instantaneously sense the pedaling force applied by a rider due to the location of torque sensors, which are typically in the wheel axle or center-mounted motor, limiting their ability to provide timely assistive power based on the rider's movement conditions.
Innovation Solution
A force detection and transmission mechanism integrated into the pedal, comprising a pedal body, force detection module, rotation shaft, insulating sleeve, electrically conductive rings, and contact elements, allows for real-time detection and transmission of pedaling force through a signal wire connected to the control module via transmission wires.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If torque sensors are located in the wheel axle or center-mounted motor, then the sensors can detect pedaling force, but the detection response is delayed and cannot instantaneously sense the force exerted by the rider's feet on the pedals
Solution Approach 1:
The pedal assembly is segmented into distinct functional components: a pedal body for force application, a rotation shaft for mechanical transmission, and a force detection module for signal generation. This segmentation allows the force detection module to be positioned at the pedal where force is applied, enabling instantaneous detection while maintaining structural functionality.
Solution Approach 2:
A signal transmission mechanism comprising contact elements, electrically conductive rings, and transmission wires acts as an intermediary to convey detection signals from the force detection module to the control module. This intermediary system ensures real-time signal transmission without mechanical interference, resolving the delay between force application and detection response.
2Loss of time
If the force detection module is integrated into the pedal, then the detection response time is reduced, but the structural complexity of the pedal assembly increases
Solution Approach 1:
The rotation shaft serves multiple functions: it transmits mechanical rotation from the pedal, provides a mounting structure for contact elements, and acts as a conduit for transmission wires. The insulating sleeve simultaneously provides electrical insulation and structural support. This multi-functionality reduces the need for separate components, managing complexity while enabling integrated force detection.
Solution Approach 2:
The transmission wires are nested within the hollow rotation shaft, and the contact elements are positioned within the pedal body structure. This nested arrangement consolidates multiple components within the existing pedal geometry, minimizing additional structural complexity while achieving integrated force detection and signal transmission.
3Reliability
If multiple electrically conductive rings and contact elements are used for signal transmission, then the signal transmission reliability is improved, but the manufacturing complexity increases
Solution Approach 1:
Multiple identical electrically conductive rings and contact elements are used throughout the signal transmission path. This homogeneity allows for standardized manufacturing processes and assembly procedures, reducing the impact of increased component quantity on manufacturing complexity while improving signal transmission reliability through redundant pathways.
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 solution enables the electric assist bicycle to sense the rider's actual movement condition in real-time, improving the immediacy and accuracy of power assistance by integrating the force detection and transmission mechanism directly into the pedal, allowing for timely and appropriate motor assistance.
Implementation Method 1
a force detection module (30) disposed in the first accommodating space (101)... signals from the force detection module (30) are sequentially transmitted
Implementation Method 2
The plurality of contact elements (50) abut against the plurality of electrically conductive rings (70), respectively... signals from the force detection module (30) are sequentially transmitted outward through the plurality of contact elements (50), the plurality of electrically conductive rings (70), and the plurality of transmission wires (W2)
Implementation Method 3
The insulating sleeve (60) is sleeved on the rotation shaft (20)... the plurality of annular insulating regions (62) correspondingly cover the plurality of annular accommodating regions (212)
Data Source
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AI summary
A force detection and transmission mechanism for a pedal includes a pedal body (10), a force detection module (30), a rotation shaft (20), an insulating sleeve (60), electrically conductive rings (70), and contact elements (50). The pedal body (10) has a first accommodating space (101) and a second accommodating space (102). The force detection module (30) is disposed in the first accommodating space (101). The rotation shaft (20) passes through the pedal body (10). Annular accommodating regions (212) and wire perforations (2120) are recessed from a surface of the rotation shaft (20). Transmission wires (W2) pass through the wire perforations (2120). The insulating sleeve (60) is sleeved on the rotation shaft (20). Annular insulating regions (62) are recessed from a surface of the insulating sleeve (60) and correspondingly cover the annular accommodating regions (212). The electrically conductive rings (70) are respectively sleeved on surfaces of the annular insulating regions (62), and the transmission wires (W2) are correspondingly coupled to the electrically conductive rings (70). The contact elements (50) abut against the electrically conductive rings (70), respectively.