Self-indexing DHD Hammer with Wrap Spring Clutch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional down-the-hole drills (DHDs) are inadequate for directional drilling due to motor deficiencies and reliability issues, particularly in terms of torque and speed, and are prone to fatigue and failure when used in abusive environments.
Innovation Solution
A self-indexing down-the-hole drill hammer design featuring a cylindrical casing, a drill bit, a piston with helical splines, a driver sleeve, a driven sleeve, and a wrap spring, which allows for rotational indexing of the drill bit without the need for additional motors, reducing torque and rpm requirements and enhancing durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional down-the-hole motor is coupled with a conventional DHD for directional drilling, then rotational capability is provided, but the device becomes more susceptible to fatigue stresses and failure due to long lengths
Solution Approach 1:
The patent removes the conventional down-the-hole motor from the system and replaces it with a simpler piston-driven mechanism. The motor is extracted as a separate surface-based power source, leaving only the hammer mechanism down-hole, which eliminates the fatigue issues associated with long motor assemblies while maintaining directional drilling capability through controlled rotation of the drill string at the surface.
Solution Approach 2:
The system is segmented into two separate components: a surface-based motor system that provides rotational power, and a down-hole hammer mechanism that performs the drilling. This segmentation allows the motor to be positioned where it can be maintained and replaced more easily, while the down-hole component remains simpler and more reliable.
2Reliability
If conventional DHDs are used for directional drilling, then they can maintain structural integrity, but they cannot provide the necessary torque and speed for directional drilling requirements
Solution Approach 1:
The patent replaces the conventional motor-driven mechanical system with a pneumatic or hydraulic piston-driven hammer mechanism. This substitution provides higher torque and speed capabilities through the explosive force of pressurized gas or fluid acting on the piston, while maintaining structural integrity by using a simpler, more robust hammer design without complex motor components.
3Adaptability or versatility
If rotation devices are added to DHD assemblies to induce rotation, then rotational capability is achieved, but the devices become unreliable and prone to failure due to complexity and sensitivity to abusive environments
Solution Approach 1:
The patent extracts the rotation function from the down-hole assembly and places it at the surface. Instead of adding complex rotation devices to the DHD, the system uses surface-based drill string rotation, which is far more reliable in abusive environments and easier to control for directional drilling applications.
Solution Approach 2:
The drill string serves multiple functions: it transmits rotational power from the surface motor, supports the down-hole hammer, and enables directional drilling through controlled rotation. This universal use of the drill string eliminates the need for separate rotation devices in the down-hole assembly.
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
Enables directional drilling with improved reliability and reduced internal stresses, allowing for larger drill bit shanks and increased torque forces, thus overcoming the limitations of conventional DHDs.
Implementation Method 1
a wrap spring circumscribing the driver sleeve and the driven sleeve. A plurality of bearings is configured within the plurality of openings of the driver sleeve to operatively engage the helical splines for rotationally indexing the drill bit
Implementation Method 2
The a piston mounted within the casing to reciprocally move within the casing along a longitudinal direction and includes a plurality of helical splines on a piston surface
Implementation Method 3
The a piston mounted within the casing to reciprocally move within the casing along a longitudinal direction
Data Source
AI summary
A down-the-hole drill (DHD) hammer having a casing, a drill bit proximate a distal end of the casing, a piston mounted within the casing and a self-indexing drive transmission is provided. The piston includes a plurality of helical and axial splines. The drive transmission includes a driver sleeve, a driven sleeve and a wrap spring clutch assembly. The driver sleeve and driven sleeve are housed within the casing and circumscribes the piston. The driver sleeve includes a plurality of openings for receiving a plurality of bearings. The driver sleeve bearings are configured to operatively engage the helical splines on the piston. The wrap spring clutch assembly includes a wrap spring circumscribing the driver sleeve and driven sleeve. The driven sleeve operatively engages the drill bit to rotationally index the drill bit.