Load-Sensing Washer With Wireless Clamping Force Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for determining the clamping force of bolted joints are time-consuming and imprecise, particularly in applications involving vibration, cyclic loading, or temperature variations, and there is a need for real-time monitoring and historical record-keeping of clamping forces.
Innovation Solution
An instrumented washer with integrated strain gauges and a communication assembly, including an integrated circuit and antenna, that wirelessly transmits load information to a reader device, allowing precise measurement and monitoring of axial clamping forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional torque-based methods are used to determine clamping force, then the measurement process is simple, but the measurement precision and accuracy are insufficient
Solution Approach 1:
The patent combines strain gauges, integrated circuit, and antenna into a single instrumented washer assembly. The strain gauges are mounted on the washer body, the integrated circuit is embedded within the washer, and the antenna is integrated into the assembly, creating a unified measurement device that provides precise clamping force measurement without requiring separate complex equipment
Solution Approach 2:
The patent replaces conventional mechanical torque-based measurement methods with an electrical sensing system using strain gauges that convert mechanical deformation into electrical signals. This substitution enables direct measurement of clamping force through electrical resistance changes in the strain gauges, providing superior accuracy compared to indirect torque-based estimation
2Productivity
If conventional torque-based methods are used, then the equipment is simple, but the time required for measurement is excessive
Solution Approach 1:
The instrumented washer enables continuous or periodic monitoring of clamping force throughout the operational life of the bolted joint. The strain gauges continuously measure the load, and the integrated circuit continuously stores this data, allowing for real-time assessment without interrupting the operational process or requiring repeated manual measurements
Solution Approach 2:
The instrumented washer is self-measuring and self-reporting. The strain gauges automatically detect clamping force changes, the integrated circuit automatically stores and manages the data, and the antenna automatically transmits information when queried. This eliminates the need for manual intervention, time-consuming measurement procedures, and repeated inspections by operators
3Measurement precision
If strain gauges and communication assembly are integrated into the washer, then clamping force measurement accuracy is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent segments the manufacturing process into distinct phases: first manufacturing the washer body with integrated circuit embedding, then separately mounting strain gauges on the washer surface, and finally integrating the antenna assembly. This segmentation allows each component to be manufactured and tested independently before final assembly, simplifying the overall manufacturing complexity while maintaining measurement precision
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
Enables rapid, accurate determination and recording of clamping forces in bolted joints, facilitating efficient installation and maintenance, and providing historical data for analytical purposes.
Implementation Method 1
One or more strain gauges are provided on the circumferential sidewall and are configured to sense a deformation of the washer body do to clamping forces of the bolted joint
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
An instrumented, load-sensing washer that can be used on a bolted joint to facilitate determining an axial clamping load of the bolted joint. The washer includes an annular washer body having first and second oppositely disposed axial ends and an outer circumferential sidewall. At least one strain gauge is provided on the circumferential sidewall and is configured to sense a deformation of the washer body do to clamping forces of the bolted joint. The washer further includes a communication assembly operatively coupled with the at least one strain gauge. The communication assembly may include an integrated circuit adapted to receive electrical signals from the at least one strain gauge related to the axial load borne by the washer.