Drill String Impact Device With Stress-Relieving Coil Grooves
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Solution Overview
Problem
Existing impact devices in drill strings face issues with stress concentration and curvature in the transition region of electrical lines due to axial longitudinal changes, leading to potential damage during repeated actuation and oscillations.
Innovation Solution
The implementation of coil-like grooves on pipe sections to accommodate the central section of the electrical line, ensuring it remains stress-free and connected securely to the pipe elements, with optional additional fastening means like clamps or sleeves to maintain stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the electrical line is wound coil-like around the pipe element to compensate for longitudinal changes, then the line can accommodate axial movements, but the transition region experiences high stress and curvature that can damage the line
Solution Approach 1:
A groove is introduced as an intermediary structure between the coil-like section and the straight connecting sections. This groove acts as a mediator that gradually transitions the line from the curved coil configuration to the straight connecting section, reducing the sharp bend and distributing stress more evenly across the transition region.
Solution Approach 2:
The groove is designed with a curved profile that matches the coil-like winding pattern. This curvature allows the line to transition smoothly from the circular coil path to the straight connecting section, avoiding abrupt angular changes and reducing stress concentration at the transition point.
2Device complexity
If the line is connected directly between moving pipe elements, then the connection is simple, but the line is subjected to high stress during repeated actuation and oscillations
Solution Approach 1:
The groove is designed in advance to provide a stress-distributing structure before the line is subjected to repeated actuation and oscillations. By pre-configuring the groove geometry, the line is protected from high stress concentrations that would otherwise occur at sharp bends, thereby extending the line's service life and reliability.
3Ease of operation
If the line has sharp bends in the transition region, then the line can be routed between pipe elements, but the sharp bends create stress concentration during oscillations
Solution Approach 1:
The groove is designed with a curved profile that replaces sharp angular bends with gradual transitions. This curvature allows the line to be routed effectively between pipe elements while distributing stress more evenly, eliminating the stress concentration that would occur at sharp bends during oscillations and repeated actuation.
Data Source
AI summary
An impact device for a drill string has a pipe with a variable length and a longitudinal extension, which has a first pipe element and a second pipe element that can be moved in the direction of the longitudinal extension relative to the first pipe element, which second pipe element is accommodated in the first pipe element. An electrical line runs from the first pipe element to the second pipe element, which line is connected to the first pipe element and the second pipe element and is wound coil-like in a central section around the second pipe element. A coil-like groove is arranged on the first pipe element and/or on the second pipe element, in which groove lies an area of the central section of the line.