Design features:

• All shaft supports are roller bearings. Materials for the shafts are alloy steel.

• Forced lubrication is used for all chains.

• Grooved drum: there are ventilating air tube clutches at the high/ low speed end of the drum. Circulated water forced cooling mode is adopted for brake hub (the brake disc of disc brake uses circulated water forced cooling or air cooling), which has been surface quenched, with good wear resistance, long service life.

• Sprocket tooth profile surface has been quenched at the intermediate frequency. All shifting clutches are involute spline gear clutch.

• The main brake is band brake or hydraulic disc brake. Auxiliary brake has been equipped with eddy electromagnetic brake or EATON brake.

The design features of mono-shaft drawworks:

• The mono-shaft drawworks consis ts of AC VF motor, gear reducer, hydraulic disc brake, DW frame, drum shaft assembly, auto-bit feeding device and control system etc.

• The drawworks is driven by AC VF motors, which is powerful and with a wide VF speed regulation scope.

• Gear drive has high efficiency, with less vibration and low noise, and has long service life.

• There is no shifting device with the drawworks, and stepless regulation has been done by controlling AC VF regulator.

• The drawworks structure is mono-shaft grooved drum; compare with the same type drawworks, it has less par ts , smaller volume and less weight.

• The main brake of the drawworks is hydraulic disc brake, and the auxiliary brake is dynamic brake.

• The drawworks is equipped with separate AC VF drive device and computer auto control system, has auto bit feeding function, and the functions of real time control, monitoring and analysis of tripping in condition and drilling condition, to realize optimizing drilling operation.