The shank adapter is the transmission connection part between the rock drill and the drill rod, and its main function is to directly bear the impact and the torque of the rock drill. Common shank adapters are mainly divided into three categories: flange-type shank adapters, lug-type shank adapters, and spline adapters. The cross-section of the flange-type shank adapter is hexagonal, 22mm or 25mm for the inscribed circle diameter and 108mm or 159mm for length. It is manufactured by the forging process and is used for light rock drills. The lug-type shank adapter is used for inner-rotating medium-sized guide-type rock drills, and the diameter of the drill rod is 25mm or 32mm. The spline adapter is often used for heavy-duty guide-type external rotating rock drills with large torque, and the diameter of the drill rod is more than 38mm. It is often manufactured by a mechanical process.
Since the shank adapter is an important part of the drilling tool, it is also one of the large quantities of scrapped consumables in the rock drilling site. Even so, the concept of scrap and failure is different. We can adjust to prevent the failure of the rock drilling tools, so as to improve the service life of rock drilling tools. Previously, we shared 15 common solutions for button bit and 11 common solutions for drill rod failure. Today we are going to share with you 13 common solutions to the failure of shank adapter.
1. The solution to the impact marks, chipped corners, and mushroomed end caused by misalignment due to worn bushings: Replace worn components.
2. The solution to the failure of approx. 25mm from strike face caused by worn chuck driver: Replace worn components.
3. The solution to the failure at the top of the spline due to lack of lubrication: Grease rock drill regularly.
4. The solution to the failure at the top of the spline due to excessive feed force: Monitor coupling temperatures and adjust feed pressure according to recommendations.
5. The solution to the failure at the top of the spline due to worn chuck driver or front bushing: Replace worn components.
6. The solution to the failure across splines due to heavy rotational torque: Adjust drilling pressures.
7. The solution to the wear on the bottom of the spline’s shoulder caused by excessive rotation when the drilling tool is retracting string: Adjust drilling pressures.
8. The solution to the failure at the front head caused by misalignment from worn front bushing: Replace worn components.
9. The solution to the failure of above threads caused by hole deviation: Employ straight hold drilling devices or systems.
10. The solution to the failure in the main body of threads caused by improperly joined in coupling sleeves too much times: Replace worn components. Do not put a worn coupling sleeve on a new drill rod. Change out-coupling sleeves with a new shank adapter.
11. The solution to the chipped thread end due to the shank adapter not being properly coupled to the drill rod: Replace the damaged or worn coupling sleeves.
12. The solution to the chipped thread end due to the drill rod end not being square: Forward for analysis.
13. The solution to pitting and galling on splines caused by excessive rotation in the soft or broken ground: Adjust the drilling pressure.
From the above content, we can see that the failure of the shank adapter is the same as the failure of other parts of the rock drilling tools, and there are many forms. But most of the failures of the shank adapter are caused by the wear or damage of other components. Therefore, in order to improve the use efficiency of the shank adapter, it is also very important to regularly check and lubricate other components. At the same time, I would like to remind everyone that since the shank adapter has a great influence on the rock drilling speed and the rock drill, and its quality directly affects the service life of the drill rod, you must choose a reliable supplier when purchasing the shank adapter, which is also a way to improve the efficiency of the use of the rock drilling tools.