Threaded Connection Assembly with Direct Drive Dog Clutch
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Solution Overview
Problem
Existing threaded connections for hydrocarbon well drilling and operation face challenges with high makeup torque requirements to prevent unscrewing, particularly under stress conditions, and existing solutions complicate the makeup process by restricting angular misalignment of male components.
Innovation Solution
A threaded connection assembly featuring tubular components with male and female threaded zones, including a direct drive dog clutch and free rotation mechanisms, allowing for easy assembly and reduced risk of unscrewing, with a shorter coupling component to distribute torsional stresses and facilitate secure locking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high makeup torque is applied to prevent unscrewing under stress, then connection reliability improves, but risk of plastification increases
Solution Approach 1:
The connection system is segmented into multiple functional zones: a make-up zone with standard threading for assembly, a transition zone with varying pitch to gradually engage threads, and a running zone with optimized threading. This segmentation allows torque to be distributed across different zones, preventing concentration of stress that causes plastification while maintaining connection reliability.
Solution Approach 2:
The threading parameters are changed along the length of the connection, with the pitch varying from the make-up zone to the running zone. This parameter change enables the connection to progress from easy make-up to secure locking without requiring excessive torque, thereby preventing plastification while ensuring reliability under stress.
2Reliability
If male components are fitted one into the other to prevent rotation and breakout, then connection stability improves, but makeup process complexity increases
Solution Approach 1:
Instead of preventing rotation through complex interlocking mechanisms, the invention inverts the approach by using a varying pitch threading that naturally guides the components into proper alignment during make-up. The non-uniform thread engagement creates self-aligning forces that simplify the makeup process while maintaining breakout prevention.
Solution Approach 2:
The connection transitions from a dynamic make-up phase with free rotation allowed to a static locked phase. During make-up, the varying pitch allows rotational movement to engage threads progressively. Once engaged, the thread geometry itself prevents breakout, eliminating the need for complex static locking mechanisms.
3Reliability
If shorter coupling component is used to distribute torsional stresses, then connection reliability improves, but manufacturing precision requirements increase
Solution Approach 1:
The coupling component has different threading qualities at different locations. The make-up zone has standard precision threading for easy assembly, while the running zone has varying pitch threading optimized for stress distribution. This local differentiation allows the short coupling to achieve both reliability and acceptable manufacturing precision by placing high-precision requirements only where absolutely necessary.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention concerns an assembly for producing a threaded connection, comprising a first and a second tubular component with an axis of revolution (4), each being provided at one of its ends (1; 3) with a male threaded zone (10; 30) produced on the external circumferential surface, said ends (1; 3) each finishing in a terminal surface (15; 35) comprising means (14; 34) together forming a direct drive dog clutch device in order to fix the first and second tubular components in rotation, and comprising a third tubular component which also has an axis of revolution (4) and is provided at each of its ends (2, 2') on its internal circumferential surface with two female threaded zones (20, 20'), one of the two male threaded zones (10; 30) being capable of co-operating on makeup with one of the two female threaded zones (20, 20') while the other male threaded zone can co-operate on makeup with the other female threaded zone, characterized in that the male end (1) of the first tubular component as well as the corresponding female end (2) of the third tubular component comprises means for free rotation (11, 21) such that at the end of makeup of said male threaded zone (10) into said female threaded zone (20), the tubular components carrying said male and female threaded zones are freely rotational with res ect to each other.