Expandable Drill Blade Wedge Locking Mechanism
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Solution Overview
Problem
Existing expandable downhole tools for drilling operations lack sufficient rigidity and stability, leading to poor sensor quality and increased stress on cutting elements due to inadequate engagement with the borehole wall.
Innovation Solution
An expandable tool design featuring a mandrel with a tubular body and slidable sleeve, where the blade is locked in place through a wedging effect created by angled slide grooves and protrusions, increasing pressure against the borehole wall and stabilizing the connection of cutting elements and sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the blade is simply positioned in the slot without locking mechanism, then the device complexity is reduced, but the rigidity and stability of the blade connection deteriorates
Solution Approach 1:
The blade connection structure is segmented into multiple functional components: the slot in the sleeve, the blade body, and the protrusion with wedge-shaped surface. This segmentation allows each component to perform its specific function while collectively achieving stable blade fixation without excessive complexity.
Solution Approach 2:
The connection mechanism transitions from a simple linear fit to a three-dimensional wedge-shaped engagement. The wedge-shaped lateral surface of the protrusion creates a multi-dimensional locking effect that prevents blade movement in multiple directions, enhancing stability without significantly increasing structural complexity.
2Ease of operation
If the blade is loosely connected to the mandrel, then the ease of operation is improved, but the measurement precision of sensors deteriorates
Solution Approach 1:
The blade connection structure implements local quality by creating a rigid, stable connection zone at the blade-mandrel interface through the wedge-shaped protrusion. This localized rigidity ensures stable sensor measurements while maintaining overall operational simplicity of the expandable tool assembly.
3Device complexity
If the blade connection is not rigidly locked, then the device complexity is reduced, but the stress on cutting elements increases
Solution Approach 1:
The wedge-shaped protrusion is pre-configured on the blade before assembly. When the blade is inserted into the sleeve, the protrusion automatically engages with the slot and the wedge shape naturally locks the blade in place, providing preliminary rigid fixation that protects cutting elements from excessive stress without requiring additional locking mechanisms.
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 wedging effect enhances the rigidity of the blade, improving its engagement with the borehole wall, reducing stress and vibration, and increasing the quality of sensor measurements by maintaining a stable connection with the formation.
Implementation Method 1
The interior and exterior slide grooves are oriented at different angles and as the sleeve slides axially along the length of the mandrel, the slide grooves lock the blade in a pre-determined position through a wedging effect.
Data Source
AI summary
In one aspect of the present invention, an expandable tool for an earth boring system comprises a mandrel with a sleeve positioned around the outer surface and a blade disposed in a slot formed in the sleeve. The sleeve is also configured to slide along the tubular body. The blade comprises an interior slide groove located on an interior surface and an exterior slide groove located on an exterior surface. A sleeve protrusion is configured to extend into the interior slide groove, while a mandrel protrusion is configured to extend into the exterior slide groove. The blade is configured to shift laterally out of the slot as the sleeve slides axially, wherein the interior and exterior slide grooves are oriented at different angles and as the sleeve slides axially along the length of the mandrel, the slide grooves lock the blade in a pre-determined position through a wedging effect.