Zollern winches to great depths

A new electrically driven rope winch from Zollern has been incorporated into a mobile gas drilling system in Russia for depths up to 5 km.

To exploit natural gas deposits in Russia, drilling can be required to depths of 5,000 metres at temperatures reaching minus 40 °C, said Zollern. To achieve this, the drilling rig with its 30 m swivel tower, rope winch and drilling unit are integrated into a vehicle that can quickly reach the drilling sites. The drill, fed from a store of 150 drill rods according to drilling depth, is moved vertically via the raised derrick and rotated by a drill drive unit.

Zollern supplied an electric rope winch for this application, with the entire drive train, consisting of an asynchronous motor and planetary gears, integrated into the inside of the rope drum. The 340 kW, oil-cooled motor was developed and produced in-house, as was the two-stage planetary gear.

Both components have been adjusted and optimised for this application. They ultimately exert a cable pull on the drum of 160 kN and offer a maximum line speed of 600 m/min, said the manufacturer. An additional hydraulic emergency drive with two spur gear stages will ensure that, if the main drive unit were to fail, the drill system can be drawn out of the drill hole to prevent damage.

Peter Berger, designer of the new rope winch, explained, "Because it is mounted on the vehicle, it was impossible for the winch to be even 10 mm wider, so we had to optimise every single detail. We had to carry out this space-saving optimisation, keeping the demand for protection from explosion accidents in mind."