Symmetrical Load Cell Mounting With Shear-Buffering Cavities
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Solution Overview
Problem
Conventional load cells suffer from unbalance and structural design limitations that lead to low resolution and inaccurate readings due to the transmission of shear forces, impacting the fidelity of sensor measurements.
Innovation Solution
A load cell assembly with a symmetrical mounting arrangement and cavities in the frame to buffer horizontal shear forces, utilizing elastically-deformable flexure members and force sensors arranged symmetrically about a central axis to mitigate distortion and improve measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional load cell structure is used, then the device is simple, but measurement precision deteriorates due to shear force transmission and structural unbalance
Solution Approach 1:
The load cell structure is segmented into distinct functional zones: a mounting arrangement for force application, a cavity region for shear force buffering, and a sensor arrangement for measurement. This segmentation isolates the sensing zone from disturbing shear forces while maintaining overall structural integrity, thereby improving measurement precision without excessive complexity
Solution Approach 2:
The cavity acts as an intermediary element between the mounting arrangement and the sensor arrangement. It buffers and isolates horizontal shear forces generated by applied loads, preventing these forces from reaching the sensors. This intermediary structure improves measurement accuracy by eliminating shear force interference while adding minimal structural complexity
2Measurement precision
If symmetrical mounting arrangement with cavities is implemented, then measurement accuracy improves, but device complexity increases
Solution Approach 1:
While the overall mounting arrangement is symmetrical for balance, the cavity geometry and positioning are specifically designed to address asymmetric shear force distribution patterns. The cavities are strategically placed and dimensioned to buffer horizontal shear forces effectively, improving resolution by eliminating asymmetric force transmission to sensors
3Measurement precision
If shear forces are buffered through cavity design, then measurement fidelity improves, but manufacturing complexity increases
Solution Approach 1:
The cavity dimensions, depth, and positioning are optimized as specific geometric parameters to achieve effective shear force buffering. By carefully selecting these parameters, the design achieves high measurement fidelity while maintaining manufacturability through standard machining or molding processes, avoiding excessive manufacturing complexity
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 load cell assembly achieves highly accurate measurements with a 0.02% error threshold by buffering shear forces, allowing for faithful force measurements without the need for reference tables, and is applicable to various measurement applications with fewer parts and easier configuration changes.
Implementation Method 1
The flexure elements, and thus the force sensor(s), are responsive to one or more forces applied to a solid body frame of the assembly during a weighing and/or measuring operations
Data Source
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AI summary
Disclosed is a load cell having a frame that includes a first and a second mounting surface. Each mounting surface is arranged on a common horizontal plane symmetrically about a central vertical axis. First and second lateral surfaces are arranged perpendicular to the first and second mounting surfaces. One or more mounting fixtures are located on the load cell at the first and second mounting surfaces and configured to attach to a support structure or a loading fixture. One or more force sensors are arranged symmetrically about the central vertical axis. One or more cavities extend the width of the frame and are arranged between a mounting fixture and the force sensors.