Jackbolt Compression Generator for Pipe Joint Stability
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Solution Overview
Problem
Existing technologies face challenges in creating a reliable and secure friction locking mechanism for pipe connections in sub-sea environments, which are prone to vibrations, axial tensions, and sideways loads, leading to inadequate locking and potential leakage of pressurized fluids in machinery.
Innovation Solution
A compression generator using multiple jackbolts to generate a higher clamping force by transmitting torque to a main element, which is releasably joined to a fixed part, creating friction between mechanical elements and distributing the load across multiple jackbolts to form a more resistant joint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional single bolted joint is used to press two elements apart, then the structure is simple, but the joint is detrimentally sensitive to vibrations causing unintentional loosening
Solution Approach 1:
The single bolted joint is segmented into multiple jackbolts (typically 3-6) distributed around the compression element. Each jackbolt independently contributes to the total clamping force, and the distribution of multiple fasteners prevents localized stress concentration and reduces sensitivity to vibration-induced loosening.
Solution Approach 2:
Multiple jackbolts are combined to work together as a unified fastening system. The collective clamping force from all jackbolts creates a distributed friction lock across the compression element, combining individual weak links into a strong, vibration-resistant joint.
2Strength
If friction locking is used in sub-sea environments, then the locking mechanism is simple, but it is difficult to withstand strain from waves, axial tensions, vibrations, and sideways loads
Solution Approach 1:
The compression element is designed with specific local qualities including a friction surface with optimized coefficient of friction, distributed contact areas, and geometric features that maximize frictional engagement. The jackbolts are positioned to create optimal local stress distribution across the compression element.
Solution Approach 2:
The jackbolts are pre-tensioned to apply clamping force before the joint is subjected to environmental strains. This preliminary compression creates a friction lock that prevents relative movement between joined elements, preparing the joint to resist subsequent waves, axial tensions, vibrations, and sideways loads.
3Reliability
If multiple jackbolts are used to generate higher clamping force, then the friction locking is more reliable, but the device complexity increases
Solution Approach 1:
The main element serves multiple functions: it provides the structural framework for mounting jackbolts, acts as the compression element that generates friction, and serves as the interface for the compression generator. The jackbolts simultaneously provide clamping force and positioning functionality.
Solution Approach 2:
The friction locking mechanism is self-service in that the clamping force from jackbolts automatically generates the necessary friction to prevent joint separation. The system self-regulates through friction feedback, where the compression force and friction coefficient naturally balance the applied loads without additional control mechanisms.
4Ease of operation
If torque is applied to create friction in pipe couplings, then the locking operation is simple, but the friction locking is not always reliable under severe localized strains
Solution Approach 1:
The joint transitions from a static friction lock during installation to a dynamic friction lock during operation. The compression element is designed to maintain frictional engagement under dynamic loading conditions including vibration, axial motion, and lateral forces, adapting the friction force to match the applied strains.
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 provides a significantly more resistant joint to vibrations and axial, radial, and sideways forces, preventing unwanted leakage and ensuring a secure connection in sub-sea environments and pressurized systems.
Implementation Method 1
generate friction by transmitting a pushing force against a surface of a moveable part
Data Source
AI summary
A compression generator uses a plurality of jackbolts threadedly engaged at a spaced apart relation about a bolt circle in a main core element. The main core element is releasable interlocked by threads, bayonet connection or other form of fasting system with the mounting element forming a fixed part of the mechanical connection. The jackbolts torqued to generate a pushing force in an axial direction for compressing a moveable part of the mechanical connection against a compression seat for forming a mechanical connection between juxtaposition fixed and moveable parts.