Kinetic characteristics analysis of a new torsional oscillator based on impulse response

For reducing the sticking or stick–slip phenomenon, this paper proposed a new torsional oscillator which could produce a circumferential torque vibration in the drilling process. Based on the working principle and fundamental structure, the generation mechanism of torsional vibration and the relationships of the mechanical parts are derived. Then, the dynamic model is established according to the drilling operation condition. With this, the further analysis of changing relationship between the inlet flow and torque is studied. The angular displacement and velocity of the valve body are analyzed according to the dynamics theory models. With the combination of the theoretical analysis model, the parameter studies are carried out by numerical example calculation. Finally, experiment test is conducted to identify the accuracy and reliability of the calculation method under the corresponding working conditions. The results show that with the constant pressure the average torque is proportional to the inlet flow. However, while the inlet pressure is invariable, the collision period is inversely proportional to the inlet flow, and the angular displacement and velocity are proportional to the inlet flow. The research results can provide references for the design and application of the torsional vibration tools, which is potential and significant in drilling engineering.