DHD Drill Bit Spiral Inserts Reduce Rock-Breakage Energy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional down-the-hole drill (DHD) hammers with concentrically arranged cutting inserts require more energy for rock breakage due to the creation of concentric grooves or valleys, which are less efficient for rock penetration as they move the free rock surfaces away from the Hertzian stress field.
Innovation Solution
A drill bit for DHD hammers featuring cutting members arranged in a nonconcentric or spiral configuration, which reduces the formation of concentric grooves and overlaps cutting paths to enhance drilling efficiency by aligning free rock surfaces closer to the stress field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If cutting inserts are arranged in concentric rings, then the drill bit structure is simple and easy to manufacture, but more energy is required for rock breakage due to creation of concentric grooves
Solution Approach 1:
The patent applies asymmetry by transitioning from symmetric concentric ring arrangements to asymmetric nonconcentric and spiral patterns. The cutting members are positioned at varying radial distances from the central axis, creating an asymmetric distribution that prevents formation of concentric grooves and valleys, thereby reducing energy requirements for rock breakage while maintaining structural feasibility
2Ease of manufacture
If cutting inserts are arranged in concentric rings, then manufacturing is easier, but concentric grooves or valleys are created that increase energy consumption
Solution Approach 1:
The patent employs asymmetric nonconcentric and spiral arrangements of cutting members that depart from traditional concentric patterns. This asymmetric configuration eliminates the formation of concentric grooves and valleys, directly addressing the energy consumption issue while remaining manufacturable through standard drilling and mounting processes
3Productivity
If cutting inserts are arranged in concentric rings, then the drill bit structure is conventional and simple, but free rock surfaces are moved away from the Hertzian stress field reducing breakage efficiency
Solution Approach 1:
The patent implements asymmetric nonconcentric and spiral patterns that reposition cutting members to maintain closer proximity between free rock surfaces and the Hertzian stress field during penetration. This asymmetric arrangement improves rock breakage efficiency by optimizing stress distribution while avoiding the formation of energy-consuming concentric grooves
Solution Approach 2:
The patent introduces spiral arrangements that add a rotational dimensional component to the cutting member distribution. Rather than simple radial positioning in concentric rings, the spiral configuration creates a three-dimensional cutting pattern that overlaps paths and maintains efficient stress field interaction throughout the drilling process
Data Source
AI summary
A drill bit for a down-the-hole drill hammer is provided that includes a head and a shank extending from the head. The head includes a plurality of non-concentrically or spirally arranged cutting members about its working face. The non-concentric or spiral arrangement of the cutting members in the drill bit and their overlapping cutting paths during rotation of the drill bit reduces the presence of concentric grooves or valleys being cut into the earthen terrain impacted by the bit thereby resulting in more complete cutting coverage.