[Abstract] papers DQZJ - 20Y hydrodynamic drive rigs used hydraulic mechanical gearbox, transmission soft, adapt to the changes in the load capacity can be achieved continuously variable torque and braking inversion. Field test showed that the rig power utilization, and high hoisting speed; Conversely braking characteristics reduce the belt brake load; Moments change the characteristics of strengthening the ability to handle incidents. Through the torque converter drive drilling pump can simultaneously protecting the original motivation and work; Maintain the rated speed of the diesel engine conditions, pump pressure can be controlled throughout the entire process. Thermal response, reverse gear clutch and filters, etc. exposed to the issues raised improvements.