Down-The-Hole hammer drilling system driven by a tubular reciprocating translational motion permanent magnet synchronous motor

This paper presents a Down-The-Hole (DTH) hammer drilling system driven by a tubular reciprocating translational motion permanent magnet synchronous motor for offshore oil & gas industry. The mathematical models of electric part, mechanical part and load are presented based on force analysis of motor and dynamic analysis of impact. The simulation results validate the mathematic model and show that the motor can be utilized in percussive drilling applications and achieve a very large impact force. The design issues of DTH hammer system due to space limitation and harsh operating conditions are also presented from control point of view for percussive drilling applications.