Wireless Spoke-Type Crankset Torque Sensor for Sensitive Deformation Detection
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Solution Overview
Problem
Resistance strain gauges attached to the front of a bicycle spoke bar fail to accurately sense the deformation of the spoke-type elastomer due to the large area, leading to insensitive sensing.
Innovation Solution
A wireless transmission bicycle crankset spoke-type torque sensor with a five-way-end stationary circuit housing, incorporating a power source transmitting coil, resistance strain gauges on the spoke bars, and a rotating torque circuit board with a magnetic ring and Hall element, allowing for sensitive detection of deformation through wireless transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If resistance strain gauges are attached to the front of the spoke bar, then the sensing area is increased, but the sensitivity to detect deformation decreases
Solution Approach 1:
The patent applies local quality by placing resistance strain gauges on specific localized regions of the spoke bar (front surface near the hub and side surface near the rim) rather than distributing them uniformly across the entire front surface. This concentrated placement on critical stress zones maximizes deformation detection sensitivity while using minimal gauge area, directly resolving the contradiction between sensing area and measurement precision.
2Area of stationary object
If resistance strain gauges are attached to the front of the spoke bar, then the installation area is increased, but the ease of sensing deformation decreases
Solution Approach 1:
The patent identifies and targets specific local regions on the spoke bar where deformation occurs most significantly - the front surface near the hub and the side surface near the rim. By concentrating the strain gauge installation on these critical local areas rather than the entire front surface, the patent makes deformation sensing much easier and more effective while minimizing the total installation area.
3Ease of operation
If wireless transmission is implemented, then the complexity of wiring is reduced, but the need for additional components (coils, circuits) increases device complexity
Solution Approach 1:
The patent replaces the mechanical wiring system with an electromagnetic field-based wireless transmission system. Induction coils and modulation circuits convert mechanical deformation signals into electromagnetic signals that can be transmitted wirelessly to the bicycle controller, eliminating the need for physical wire connections while managing the added electronic components through integrated circuit design.
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 sensor effectively senses the deformation of the spoke-type elastomer, improving sensitivity by detecting changes in resistance values, and transmitting torque signals wirelessly to a controller.
Implementation Method 1
the resistance strain gauges fail to easily sense the deformation of the spoke-type elastomer, leading to insensitive sensing
Implementation Method 2
a power source transmitting coil, a power source induction receiving coil
Implementation Method 3
a Hall element and a magnetic ring
Data Source
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AI summary
Disclosed is a wireless transmission bicycle crankset spoke-type torque sensor, which belongs to the field of bicycles. The torque sensor comprises a five-way-end stationary circuit housing (1). The structural feature of the torque sensor lies in further comprising a power source transmitting coil (3), a power source induction receiving coil (4), a resistance strain gauge (5), a stationary circuit board (7), a sensor torque signal receiving circuit (8), a spoke-type elastomer (12), a sensor torque signal transmitting circuit (13), a power source induction receiving modulation circuit unit (14), a rotating torque circuit board (17), a Hall element (18) and a magnetic ring (19), wherein the stationary circuit board (7) is arranged inside the five-way-end stationary circuit housing (1); the power source transmitting coil (3), the sensor torque signal receiving circuit (8) and the Hall element (18) are arranged on the stationary circuit board (7); the rotating torque circuit board (17) and the resistance strain gauge (5) are both arranged on the spoke-type elastomer (12); and the power source induction receiving coil (4), the sensor torque signal transmitting circuit (13), the power source induction receiving modulation circuit unit (14) and the magnetic ring (19) are arranged on the rotating torque circuit board (17).