Telescoping Drill Drive Unit for Dual Pipe HDD
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Solution Overview
Problem
Existing directional boring machines face challenges in efficiently steering and managing dual pipe drill strings during underground drilling operations, particularly in maintaining precise control over the angle and length of drill rods, which affects drilling accuracy and efficiency.
Innovation Solution
A drill drive unit with telescoping outer and inner drive shafts that can rotate independently, allowing for the connection and disconnection of drill rods, along with a break-out mechanism that includes vises for securing and aligning rods, enables precise control over the drill string's angle and length, facilitating efficient rod addition and removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a dual pipe drill string configuration is used, then drilling accuracy and steering capability are improved, but device complexity and operational difficulty increase
Solution Approach 1:
The drill string is divided into separate inner and outer pipes that can be independently manipulated. The inner pipe contains the drill bit and can rotate independently, while the outer pipe provides structural support and can be steered separately. This segmentation allows independent control of drilling and steering functions, improving drilling accuracy while managing complexity through functional separation.
Solution Approach 2:
A coupling mechanism serves as an intermediary between the inner and outer pipes, allowing selective connection and disconnection. This intermediary component enables the system to switch between connected dual-pipe mode (for improved accuracy) and separated mode (for reduced complexity during specific operations), resolving the contradiction between precision and complexity.
2Measurement precision
If independent rotation of inner and outer drive shafts is implemented, then control precision over drill string angle is improved, but ease of operation deteriorates
Solution Approach 1:
The drive system transitions from static fixed rotation to dynamic independent rotation of inner and outer shafts. The inner drive shaft can rotate at different speeds and directions relative to the outer shaft, allowing real-time adjustment of drill string angle and orientation. This dynamic control improves measurement precision while the automated coupling mechanisms maintain ease of operation.
Solution Approach 2:
The system incorporates feedback mechanisms that monitor the rotational positions and angles of both drive shafts. This feedback enables automated control systems to maintain precise angular control by continuously adjusting shaft rotations based on measured deviations, improving control precision while reducing manual operational complexity through automation.
3Productivity
If telescoping drive shafts with independent rotation are used, then productivity in rod addition and removal is improved, but device complexity increases
Solution Approach 1:
The inner drive shaft is nested within the outer drive shaft, with the inner shaft telescoping in and out of the outer shaft. This nesting arrangement allows compact storage when not in use and enables quick deployment during rod addition operations. The telescoping mechanism reduces the time required for rod handling, improving productivity while the integrated nested design minimizes the space and components required, managing device complexity.
Data Source
AI summary
The present disclosure provides a drill drive unit and drill string make up and break up unit with a method for use with a dual pipe drill string configuration. The drill drive unit is mounted to a single carriage and includes an outer drive spindle in a position fixed to the carriage with inner drive spindle configured to rotate independent of the outer drive spindle while being able to move longitudinally at least 12 inches relative to the outer drive spindle. The method involves connecting and disconnecting inner shafts and outer shafts of the dual pipe drill string.