A Draw works is the primary hoisting machinery that is a component of a rotary drilling rig. Its main function is to provide a means of raising and lowering the traveling blocks. The wire-rope drilling line winds on the draw works drum and extends to the crown block and traveling blocks, allowing the drill string to be moved up and down as the drum turns. The segment of drilling line from the draw-works to the crown block is called the “fast line”. The drilling line then enters the sheaves of the crown block and it makes several passes between the crown block and traveling block pulleys for mechanical advantage. The line then exits the last sheave on the crown block and is fastened to a derrick leg on the other side of the rig floor. This section of drilling line is called the “dead line”.
Consist: Drum and shaft assembly, brake system, cathead assembly, transmission assembly, Control system, lubrication system etc.
All sheaves and shafts are made of alloy steel.
Chains are pressure lubricated.
Drum is grooved. The low-speed & high-speed ends of the drum shaft are equipped with ventilating pneumatic tube clutch.
The brake rim (or disc) is water cooled and the surface is medium-frequency induction hardened that provides excellent wear-resistance capacity and long service life.
High pressure drilling fluid sealing system.
The main brake is hydraulic disc brake, and the auxiliary brake is electromagnetic eddy current brake.
|Max. Fast line Pull
|1 1/4(32)||1 3/8(35)||1 1/2(38)|
|Drum Size (dia.×width)
|Gears for Hoisting Speed||4+2R||Step-less speed changing||6+2R||Step-less speed changing||6+2R||Step-less speed changing|
|Main Brake||hydraulic disc brake||hydraulic disc brake, energy- consumption brake||hydraulic disc brake||hydraulic disc brake, energy- consumption brake||hydraulic disc brake||hydraulic disc brake, energy- consumption brake|