Design Features of DC Motor Driven Drawworks:
▋Bearings are roller ones and shafts are made of alloy steel.
▋On the drum there is a spiral groove. The low-speed & high-speed ends of drum shaft are equipped with a ventilating air tube clutch.
▋The main brake is of hydraulic disc type. The disc brake is water or air cooled.
▋The eddy current brake and air & water cooled brake is considered as an auxiliary brake.
▋Air shift gear structure.
▋Chain drive structure.
Basic Specifications of DC Motor Driven Drawworks:
| Model | JC40D | JC50D | JC70D | JC90D | ||
| Nominal drill depth | m | Ф114mmdrill pipe | 2500-4000 | 3500-5000 | 4500-7000 | 6000-9000 |
| Ф127mm drill pipe | 2000-3200 | 2800-4500 | 4000-6000 | 5000-8000 | ||
| Rated power | kW (hp) | 735(1000) | 1100(1500) | 1470(2000) | 2210(3000) | |
| Number × Rated Power(kW) of motors | kW | 2 ×580 | 2 ×800 | 2 ×800 | 3 ×800 | |
| Rated speed of motor | r/min | 880/970 | 970 | 970 | 970 | |
| Dia. of wire line | mm (in) | 32 (1-1/4) | 35(1-3/8) | 38(1-1/2) | 45(1-3/4) | |
| Max. pull of fast line | kN | 275 | 340 | 485 | 630 | |
| Drum (Dia× Length) | mm (in) | Band brake | 640×1235 (25-1/4 ×48-1/2 ) | 685×1245 (27×49 ) | 770×1439 (30×56-5/8) | 914×1556 (36×61-1/4) |
| Brake rim (Dia× width) | mm (in) | 1168×265 (46×10 1/2) | 1270×267 (50×10 1/2) | 1370×267 (54 ×10 1/2 ) | 1575×264 (62 ×10 3/8 ) | |
| Drum (Dia× Length) | mm (in) | Disc brake | 640×1139 (25 1/4 ×44 7/8 ) | 685×1245 （49） | 770×1361 (30 ×53 5/8) | 914×1556 (36 ×61 1/4) |
| Brake rim (Dia× width) | mm (in) | 1500×40 (59 ×1 1/2 ) | 1600×76 (63 ×3 ) | 1600×76 (63 ×3) | 1600×76 (63 ×3 ) | |
| Sandline drum (Dia× Length) | mm (in) | 356×1245 (14 ×49 ) | 356×1245 (14×49 ) | 356×1245 (14 ×49 ) | 356×1448 (14 ×57 ) | |
| Capacity of sandline drum (9/16″wire line) | m | 4000 | 5000 | 6400 | 7500 | |
| ft | (13120 ) | (16400 ) | (21000 ) | (24600 ) | ||
| Auxiliary brake | DS40 | DS50 | DS70 | DS90 | ||
| Overall dimension (L×W×H) | mm | 6600×3716 ×2990 | 6800×4537×2998 | 7670×4585 ×3197 | 7874×5486 ×2997 | |
| Weight | kg | 40000 | 48000 | 61000 | 70000 |