Hydraulic Thread Tensioning with Sensor-Guided Nut Rotation
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Solution Overview
Problem
Existing hydraulic tensioning systems for threaded members, such as those used in wind turbines, lack reliability and repeatability in applying consistent tension, making it difficult for users to accurately measure elongation and ensure proper attachment.
Innovation Solution
A hydraulic tensioning apparatus equipped with sensors to monitor displacement, pressure, and torque, along with a control unit that provides binary indicators for target rotation and pressure, enabling precise tensioning by determining the required nut rotation and pressure thresholds, and storing data for traceability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydraulic tensioning is performed using conventional methods, then the tensioning process can be completed, but the reliability and repeatability of tension application is poor
Solution Approach 1:
The patent implements feedback through sensors that monitor displacement, pressure, and torque during the tensioning process. The control unit receives signals from these sensors and compares actual values against target values, providing real-time feedback to guide the operator and ensure consistent, reliable tension application regardless of operator skill level.
Solution Approach 2:
The patent replaces manual mechanical judgment with automated electronic sensing and control. Instead of relying on operator skill to judge when target tension is reached, the system uses displacement sensors, pressure sensors, and torque sensors to objectively measure and control the tensioning parameters, eliminating variability introduced by human operators.
2Measurement precision
If elongation is calculated using hydraulic pressure and material properties, then elongation can be estimated, but the measurement precision is insufficient
Solution Approach 1:
The patent replaces indirect calculation of elongation (based on pressure and material properties) with direct measurement using a displacement sensor. The sensor physically measures the extension of the threaded member, providing accurate and reliable elongation data without relying on theoretical calculations that may have uncertainties.
Solution Approach 2:
The displacement sensor acts as an intermediary between the mechanical elongation of the threaded member and the measurement system. It directly converts the physical extension into a measurable signal, providing a reliable link between the mechanical process and quantitative measurement.
3Measurement precision
If multiple sensors and control systems are added to improve tensioning precision, then measurement precision and reliability improve, but device complexity increases
Solution Approach 1:
The control unit serves multiple functions: it receives signals from all sensors (displacement, pressure, torque), processes the data, determines when target values are reached, activates indicators, and records measurements. This multi-functional approach consolidates control logic into a single unit, reducing overall system complexity despite the presence of multiple sensors.
Solution Approach 2:
The patent combines the control unit, indicator system, and data storage functionality into an integrated system. The control unit merges signal processing, decision-making, and actuation functions, while the indicators and storage work together as a unified feedback and recording subsystem, reducing the number of separate components needed.
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 system ensures repeatable and reliable tensioning by providing real-time feedback and automatic data recording, improving the accuracy and consistency of threaded member elongation measurement and tension application.
Implementation Method 1
the provision of a linear displacement sensor which measured the extension of the workpiece
Implementation Method 2
The apparatus may be provided with a pressure sensor arranged to determine the fluid pressure within the pressure space
Implementation Method 3
A space between the inner and outer bodies defines a pressure space, into which fluid, typically hydraulic fluid, can be introduced to drive the bodies apart along their common axis
Data Source
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AI summary
A hydraulic tensioning apparatus for tensioning a threaded member (2) having a thread, comprising: a hydraulic tensioner (1), having a body (4) and a pressure space (13) for hydraulic fluid and having a thread engaging member (7) arranged to engage the thread of the threaded member (2) and to be urged away from the body (4) on introduction of hydraulic fluid into the pressure space (13) so as to tension the threaded member (2); a displacement sensor (11, 12) arranged to measure a linear displacement of the thread engaging member (7) relative to the base (4) and to provide an output indicative of the linear displacement; a rotation sensor (65, 66) arranged to determine a rotation of a nut (3) rotating on the threaded member (2) and arranged to produce an output indicative of a rotation angle of the nut (3); and a control unit (80) arranged to take as inputs the outputs of the displacement sensor (11, 12) and the rotation sensor (65, 66), and to determine from the output of the displacement sensor (11, 12) a required angle of rotation of the nut (3) which accommodates for extension of the threaded member (2) due to being tensioned by the hydraulic tensioner (1).