Anti-rotation Device for Pipe String Connectors
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Solution Overview
Problem
Existing anti-rotation solutions for pipe string connectors in the oil industry are either tool-dependent, costly due to precise manufacturing requirements, or cause permanent deformation, failing to effectively prevent unintentional disconnection during offshore operations.
Innovation Solution
A tubular pipe string element with cantilever spring arms and locking members that engage with saw-tooth profiled teeth, allowing for secure anti-rotation without additional tooling and enabling easy reusability, using a manual release mechanism to prevent unintentional disconnection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If deforming (crimping) is used to prevent rotation, then anti-rotation is achieved, but additional tools are required during connection and valuable space of the rig is occupied
Solution Approach 1:
The pipe string element incorporates spring arms with locking members that automatically engage with teeth on the connector to prevent rotation. The spring arms are integral to the pipe string element itself, eliminating the need for external anti-rotation tools during connection operations.
2Reliability
If locking screws/pins are used to prevent rotation, then anti-rotation is achieved, but very precise manufacturing is required to ensure proper alignment of radial apertures, thereby increasing cost
Solution Approach 1:
The locking members on the spring arms have asymmetric tooth profiles that engage with corresponding teeth on the connector. This asymmetric design provides self-aligning features that guide the locking members into proper engagement positions, eliminating the need for precisely aligned radial apertures.
3Reliability
If deforming (crimping) is used to prevent rotation, then anti-rotation is achieved, but permanent damage or deformation to pipe string components occurs, making components harder to reuse
Solution Approach 1:
The spring arms are designed as resilient, movable elements that can flex and retract. The locking members engage with teeth through elastic deformation of the spring arms, not permanent crimping of the pipe string components. This allows the connectors to be disconnected and reused without permanent damage.
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 effectively prevents unintentional disconnection of male and female connectors without causing permanent damage, reducing operational time and costs, and allowing for easy retraction of locking members for connection release.
Implementation Method 1
a locking member thereon which is urged by the spring force of the spring arm into the rotational path of the saw-tooth profiled tooth but which is retractable out of said path against the spring force upon engagement with the leading flank of the at least one tooth
Implementation Method 2
the or each detent member comprises a cantilever spring arm
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A tubular pipe string element has a first end with a pin connector (10) formed thereon, a second end having a box connector (1) formed thereon which is complementary to the pin connector (10). The pin and box connectors are of the rotational connector type such that, in use, the pin connector is engageable in the box connector of another pipe string element and rotatable relative thereto in a first direction in order to secure the connection and in a second direction in order to release the connection. Complementary anti-rotation means are associated with the pin (10) and box (1) connectors which cooperate to prevent unintentional relative rotation between the connectors in the second direction. The anti-rotation means comprises saw-tooth profiled, radially extending teeth (14), each having a shallow leading tooth flank angle (14a) facing in the first direction and a steep trailing tooth flank angle (14b) facing in the second direction associated with the pin connector (1), and at least one detent member (5) formed on the pipe string element in association with the box connector (10). The saw-tooth profiled teeth (14) and the detent member (5) are both rotationally and axially fast with the pipe string element Upon relative rotation in the first direction between engaged pin and box connectors (1, 10), the leading flank (14a) of each saw-tooth profiled tooth engages with one of the detent members (5), urging it to retract against biasing means and allowing the connectors to rotate into a fully connected position. The steep trailing tooth flank is trapped by the detent member when in the fully connected position so as to prevent unintentional release of the connection.