
l All bearings are roller bearings. Shafts are made of alloy steel; 
l Chains with forced lubrication can transmit with high accuracy and high strength; 
l The drum is grooved. Ventilating air clutches constitute the high and low speed ends; 
l The brake drum(brake disc) is dealt with forced cooling with circulating water; 
l The surface case was hardened with medium frequency, and is durable; 
l The tooth profile of sprocket was hardened with medium frequency. Involute splines tooth clutch worked as shifting clutch; 
l Main brake is band brake or disk brake, the auxiliary brake is eddy current brake (water-cooled 
or air-cooled). 
Features of DC drawworks: 
l All bearings are roller bearings. Shafts are made of alloy steel; 
l The drum is grooved. Ventilating air clutches constitute the high and low speed ends; 
l The brake is hydraulic disc brake. The disc of brake is water-cooled or wind-cooled; 
l The auxiliary brake is eddy current brake, water-cooled or wind-cooled; 
l Being shifted though air clutch; 
l Being transmitted through chains; 
l Chains are lubricated forcedly by thin oil, bearings are lubricated by grease; 
l Split construction.