SHANK ADAPTERS is a key component of a hydraulic rock drill that transmits rotational and impact energy. During operation, it bears complex loads transmitted by the impact piston and rotary motor of the rock drill. The typical failure of SHANK ADAPTERS is usually abnormal fracture, with a working time of less than 10 shifts. The needle tail breaks at the root or thread of the thread.

Fault analysis of abnormal fracture of SHANK ADAPTERS

Usage and maintenance issues

(1) The impact generated during the operation of the rock drill causes the connecting bolts between the rock drill and the installation plate to loosen, causing the rock drill to swing during operation.

(2) SHANK ADAPTERS guide sleeve was not replaced in a timely manner after exceeding the wear limit in the inner hole, resulting in a large gap between the rock drill and the guide sleeve, causing the front end of SHANK ADAPTERS to shake during the operation of the rock drill.

(3)Insufficient lubrication of the rock drill results in ineffective lubrication and cooling of the needle tail during rock drilling, resulting in high temperature and reduced strength of SHANK ADAPTERS.

(4)The mismatch between the pushing pressure and the impact pressure of the rock drill causes the rock drill to experience empty hitting, and SHANK ADAPTERS bears a significant impact load that should not have occurred

(5) The rock drill was not installed correctly on the propulsion beam, causing the center line of SHANK ADAPTERS to be different from the axis of the front and middle support drill holes, resulting in additional radial force on SHANK ADAPTERS.

Preventive measures for abnormal fracture of SHANK ADAPTERS

(1) Before starting each shift, check the spray of air lubricating oil on the machine head, observe whether the oil film on SHANK ADAPTERS is even, and wait until it meets the lubrication requirements before starting drilling.

(2) Check the connection between the installation bolts of the rock drill and the installation seat of the rock drill every 40 impact hours of work. It should be ensured that the bolt torque is normal, the center of SHANK ADAPTERS is coaxial with the center of the front and middle support drill holes, and the air propulsion pressure of the rock drill is less than 3 MPa.

(3) Adjust the pushing pressure in a timely manner according to the rock condition during the drilling process. When the rock hardness is high, the pushing pressure decreases, and when the hardness is low, the pushing pressure increases. To avoid empty hitting of rock drills

(4) Regularly check the inner diameter of the drill tail guide sleeve and replace it according to the cycle of 800 hours of operation. Avoid swinging phenomenon of the drill tail due to excessive wear on the inner diameter of the guide sleeve.