Varco, a subsidiary of NOV National Oilwell in the United States, is a company that develops top drives. It has developed more than 10 specifications of top drives. All products adopt electric drive types, including TDS-8SA, TDS-9SA, and TDS-10SA. And TDS-11SA top drive, adopt AC variable frequency electric drive type, AC motor; DC motor; TDS-9SA and TDS-11SA top drive use two AC motors.
The top drive drilling unit consists of the following main components:
Faucet-drilling motor assembly;
Motor bracket/guide block assembly;
Drill pipe make-up and breakout device assembly;
balance system;
cooling system;
Top drive drilling unit control system;