Hydraulic Multi-Jack Bolt Tensioners for Uniform Fastener Preload
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Solution Overview
Problem
The application of multi-jack bolt tensioners (MJTs) is time-consuming and demands precise torque sequencing to ensure even tension, which can lead to imbalance and potential catastrophic failure, especially in large-scale installations where hundreds or thousands of MJTs need to be fitted.
Innovation Solution
A hydraulic multi-jack tensioner with multiple pressure chambers and a load-bearing member that uses hydraulic pressure to displace body sections relative to the load-bearing member, allowing for efficient and uniform tensioning of fasteners through a polar array of jack bolts, enabling faster and more precise tensioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional multi-jack bolt tensioners are used with manual torque application, then the tensioning process can be completed, but the installation time becomes excessively long and the risk of tension imbalance increases
Solution Approach 1:
The patent applies hydraulic pressure through multiple pressure chambers to simultaneously tension multiple jack bolts. The hydraulic system provides uniform pressure distribution to all bolts, ensuring even tensioning while dramatically reducing installation time compared to manual torque application.
Solution Approach 2:
The tensioning process is segmented into multiple independent pressure chambers, each responsible for specific jack bolts. This segmentation allows simultaneous independent tensioning of multiple bolts while maintaining overall uniformity through centralized hydraulic control.
2Reliability
If multiple jack bolts are tightened sequentially to ensure even tension, then uniform tension distribution can be achieved, but the installation process becomes extremely time-consuming
Solution Approach 1:
Multiple jack bolts that would traditionally be tightened sequentially are merged into a simultaneous tensioning operation through the hydraulic system. All bolts receive hydraulic pressure at the same time, achieving uniform tension distribution while eliminating the time loss associated with sequential tightening.
Solution Approach 2:
The hydraulic system maintains continuous pressure application to all jack bolts simultaneously, eliminating idle time between tightening operations. This continuous action ensures uniform tension while minimizing total installation time.
3Manufacturing precision
If torque is applied to jack bolts in a predetermined sequence, then even tension distribution can be achieved, but the complexity of the operation increases and errors may occur
Solution Approach 1:
The hydraulic system automatically distributes pressure evenly to all jack bolts without requiring the operator to follow a predetermined sequence. The system self-regulates to ensure uniform tension distribution, eliminating the complexity and potential for human error associated with sequential tightening procedures.
Solution Approach 2:
The manual mechanical torque application process is replaced with an automated hydraulic system. This substitution eliminates the need for operators to manually control torque sequence and magnitude, simplifying the operation while maintaining precise tension distribution through hydraulic pressure control.
4Adaptability or versatility
If hundreds or thousands of multi-jack bolt tensioners are installed in large-scale projects, then the project scope is covered, but the total worker hours required become prohibitively high
Solution Approach 1:
The hydraulic tensioning system enables rapid installation of each multi-jack bolt tensioner, reducing the time required per unit. When scaled to hundreds or thousands of installations, this time reduction translates to prohibitively significant savings in total worker hours while maintaining the ability to cover large project scopes.
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
This solution significantly reduces the time required for MJT installation, ensures uniform tension distribution, and prevents potential failures by allowing for precise control of tensioning, even in confined spaces, while maintaining redundancy in hydraulic systems for reliability.
Implementation Method 1
a plurality of pressure chambers between the load bearing member and the body arranged to displace the at least one body section axially relative to the load bearing member in response to hydraulic pressure
Implementation Method 2
When the jack bolts 204 are torqued, a tension preload develops evenly along the stud 208, and the axial forces by the jack bolts 204 and opposite reaction force of the stud 208 create a strong clamping force between the surfaces to be fastened together
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A multi jack tensioner for applying tension to a fastener, the tensioner comprising: a body having at least one section, including a first body section formed to engage an elongate fastening member or integrally formed therewith, a load bearing member for applying force to a workpiece to be fastened and arranged for location about said fastening member adjacent the body, a plurality of pressure chambers between the load bearing member and the body arranged to displace the at least one body section axially relative to the load bearing member in response to hydraulic pressure, and a plurality of jack bolts extending between the body section and the load bearing member for further displacing the first body section from the load bearing member, wherein application of hydraulic pressure to one or more of the plurality of pressure chambers displaces the first body section from the load bearing member thereby tensioning said fastening member and whereby subsequent tensioning of the fastening member is applied by operation of the jack bolts.