Anti-rotation Device for Connector Assembly Using Self-Tapping Screws
Solution Overview
Problem
Existing anti-rotation devices for threaded connector assemblies in offshore oil and gas drilling require complex and time-consuming installation processes, often involving hammering or drilling, and may not engage effectively at the desired make-up torque, leading to insecure connections.
Innovation Solution
The use of self-tapping screws disposed 180 degrees apart, which are activated by rotation to create a shear resistive force between the threaded portions, eliminating the need for rotational clearance gaps and simplifying the installation process by avoiding the need for precise hole alignment and hammering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional anti-rotation keys are used that interface closely with connector assembly recesses, then rotation prevention is effective, but installation becomes difficult and time-consuming requiring hammering with large force
Solution Approach 1:
The anti-rotation key is designed with self-aligning features including a tapered leading end that automatically guides the key into the recess without requiring precise alignment or hammering. The key self-positions itself during installation, eliminating the need for forceful installation while maintaining secure engagement.
Solution Approach 2:
The connector assembly includes pre-formed recesses with specific geometric features (tapered surfaces, alignment features) that prepare the installation path for the anti-rotation key. This preliminary preparation allows the key to slide in easily without requiring alignment adjustments or forceful installation during the connection process.
2Reliability
If existing anti-rotation devices are installed after connection, then rotation can be prevented, but the connection may be secured at a different torque than the desired make-up torque
Solution Approach 1:
The anti-rotation key is designed to be installed simultaneously with the threading operation, before the final make-up torque is applied. The key is positioned in the recess during the threading process, ensuring that when the desired torque is reached, the key is already in place to prevent further rotation, thus maintaining torque accuracy.
Solution Approach 2:
The anti-rotation key incorporates a spring-loaded or cam-actuated mechanism that engages dynamically during the threading process. As the pin and box are rotated to the make-up torque, the key automatically engages in the recess, providing real-time rotation prevention that maintains the precise torque value without requiring post-installation adjustments.
3Manufacturing precision
If complex boring equipment is used to form precise holes for anti-rotation devices, then accurate alignment is achieved, but the process becomes labor-intensive and time-intensive
Solution Approach 1:
The connector assembly includes pre-formed recesses with built-in alignment features that guide the anti-rotation key into the correct position automatically. This self-aligning mechanism eliminates the need for complex boring equipment and manual alignment operations, allowing rapid installation while maintaining precise positioning of the anti-rotation device.
Solution Approach 2:
The anti-rotation system is divided into separate functional components: pre-formed recesses in the connector assembly and corresponding keys with alignment features. This segmentation allows the recesses to be manufactured independently with precise geometry, while the keys can be简单地 installed without requiring complex alignment equipment, thus improving productivity while maintaining 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
This solution enables faster, more accurate, and secure engagement of anti-rotation devices, preventing rotation of threaded portions relative to each other, thus ensuring connections are maintained at the desired torque without the need for complex alignment or high force installation, reducing labor and time requirements.
Implementation Method 1
activated by rotation to create a shear resistive force between the threaded portions
Implementation Method 2
self-tapping screws disposed 180 degrees apart, which are activated by rotation to create a shear resistive force
Data Source
AI summary
An improved anti-rotation device for preventing rotation of two joined tubular members of a connector assembly is provided. The connector assembly includes a first threaded portion connected to a second threaded portion. The anti-rotation device includes at least one self-tapping screw installed in an associated threaded bore formed in and tangential to a flange of the second threaded portion. When installed, the at least one self-tapping screw engages a shoulder of the first threaded portion. A partial thread is formed in the shoulder of the first threaded portion by the at least one self-tapping screw, which forms a shear-resistive force that prevents rotation of the first threaded portion relative to the second threaded portion, and thus prevents rotation of one tubular member relative to the other.