Abstract: Aiming at poor drill ability and low rate of penetration during the drilling process, a torsional vibration generator is presented. The structure and the operational principle of the torsional vibration generator are analyzed according to the torsional theory. The relationships among the collision frequency,the amount of hydraulic hammer compression, the torque, the inlet pressure, and inlet flow are obtained on the basis of its dynamic model, which is established in light of the actual working condition. Compared with the example calculation, the experimental test verifies the accuracy and reliability of calculation method. The research results show that when the inlet pressure keeps constant, the collision frequency, the amount of hydraulic hammer compression, and the torque are inversely proportional to the inlet flow; while when the inlet flow is constant, the collision frequency, the amount of hydraulic hammer compression, and the torque are proportional to the inlet pressure.

Key words: torsional vibration generator, torque, vibration, pressure, frequency