This kind of rig is available in four models 1000HP, 1500HP,1500HP, 2000HP. Power: three-(or four)-diesel-engine (2000 or 3000 series) linkages, which are connected with couplers and reducer casings. * The drawworks and the mud pump are mechanically driven. The rotary table is independently driven by an AC/DC variable frequency motor. * Easy installation and better sealing as a result of taking an integral chain box or V-belt compound transmission unit. * The drawworks is equipped with the grooved drum and shifting a gear for it is carried out by air cylinders. The hydraulic disc brake is regarded as main brake and the eddy current brake as auxiliary brake. * The rotary table is driven independently by AC variable frequency motor and can accomplish stepless speed regulation with 0~210r/min. AC is supplied by an auxiliary generator set. * Main mechanical parts are manufactured in conformity with API Spec and applied API monogram on them.