Capacitance Torque Sensor Movable Portion Gap Amplification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitance-type torque sensors face challenges in increasing sensitivity without enlarging the sensor size, as narrowing the gap between electrodes has a lower limit, and increasing electrode area results in a larger sensor size.
Innovation Solution
A displacement detection device with a movable portion that amplifies the gap change relative to the displacement, using elastic members with inclined portions to amplify the capacitance change, allowing for higher sensitivity without increasing the sensor size, and a torque sensor incorporating this device with an inner and outer ring and elastically deformable bodies for enhanced sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the gap between opposing electrodes is narrowed to increase sensitivity, then detection sensitivity is improved, but the gap reaches a lower limit value that prevents further narrowing
Solution Approach 1:
The patent transforms the direct linear relationship between displacement and gap change into an amplified relationship by introducing a movable portion with inclined surfaces. When the second member displaces in the measurement direction, the movable portion converts this displacement into a larger gap change through its inclined geometry, effectively adding a mechanical amplification dimension to the detection system.
Solution Approach 2:
The patent changes the geometric parameters of the movable portion, specifically the angles of the inclined surfaces, to optimize the amplification ratio. By adjusting these parameters, the system can achieve higher sensitivity without physically narrowing the electrode gap beyond its minimum limit, allowing flexible tuning of the detection characteristics.
2Measurement precision
If the area of opposing electrodes is increased to increase sensitivity, then detection sensitivity is improved, but the size of the entire sensor increases
Solution Approach 1:
Instead of increasing sensitivity by enlarging the electrode area in two dimensions, the patent introduces a mechanical amplification dimension through the movable portion. This allows the system to achieve high sensitivity with compact electrode areas, effectively trading spatial expansion for mechanical leverage.
Solution Approach 2:
The movable portion acts as an intermediary mechanical element between the displacement to be measured and the capacitance detection system. It amplifies the input displacement into a larger gap modulation, serving as a mechanical mediator that enhances sensitivity without requiring larger electrodes or sensors.
3Measurement precision
If a movable portion with amplification function is added, then detection sensitivity is increased without increasing sensor size, but the device complexity increases
Solution Approach 1:
The patent divides the sensor into distinct functional segments: a fixed portion attached to the first member, a movable portion with inclined surfaces that provides amplification, and opposing electrodes. This segmentation allows each component to be optimized independently and simplifies the overall design by clearly separating the amplification function from the detection function.
Solution Approach 2:
The movable portion is designed as an elastic member with inclined surfaces that can deform elastically in response to displacement. This flexible design allows the amplification mechanism to be achieved through simple elastic deformation rather than complex mechanical linkages, reducing overall device complexity while maintaining the amplification function.
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 solution increases detection sensitivity without enlarging the sensor components, providing high accuracy and reducing interference from external forces, while maintaining a compact design.
Implementation Method 1
a movable portion connected to the first member and the second member and configured to change a gap in accordance with the displacement of the second member relative to the first member
Implementation Method 2
a detection unit configured to detect the displacement of the second member relative to the first member in the predetermined direction, based on a change in the gap
Implementation Method 3
an elastically deformable body connected to the inner ring and the outer ring, wherein in the elastically deformable body, rigidity in a torque direction is smaller than rigidity in directions other than the torque direction
Data Source
AI summary
A displacement detection device and a torque sensor include a movable part that is connected to a first member and to a second member and that changes a gap along with displacement of the second member with respect to the first member in a prescribed direction; and a detection part (detection circuit) that, on the basis of the change in the gap detects displacement of the second member with respect to the first member in the prescribed direction, wherein the movable part is configured to make the amount of N change in the gap greater than the amount of displacement of the second member with respect to the first member in the prescribed direction.