Top drive

A top drive is a machine for driving the drill string of a drilling rig. He replaced with modern rigs since the mid- 1980s, the formerly common turntable drive. The power head is when drilling the drill string, hence the English name Top Drive.

Requirements of the machine

To be able to drill at all, the power head must be supported so the mast of the rig. Method it is in most cases, with a pulley which is driven by the drill rig elevator.

In addition, the top drive has all of the mass of the drill string, which may be more than 1000 t can mechanically wear.

Furthermore important for the drilling by the rotary drilling method is the transmission of high-pressure drilling fluid to the connected drill pipe. In addition, the top drive is used in many cases of handling of the rod.