Space exploration with Pfaff-silberblau worm gear screw jacks from Columbus McKinnon Engineered Products

In the South African Karoo semi-desert, astronomers working on the MeerKAT project are using 64 radio telescopes from the German manufacturer Vertex Antennentechnik to explore space. The elevation movement of the antennas is effected using the innovative technology from Columbus McKinnon Engineered Products, Kissing. To meet the customer's exacting requirements, the engineers had to quickly devise a special drive system. In a record time of just three months from the initial request everything was accomplished from the concept design, development, prototype for testing of test scenarios through to the release for series production. The TQS 200 is a new Pfaff-silberblau torque screw jack, which now allows the inclination of the radio telescopes measuring 13.50 m in diameter to be adjusted free from backlash and to the precise millimetre. Altogether, the individual Vertex antennas combine to form what is known as a square kilometre array (SKA) – which is today regarded as the largest radio telescope in the southern hemisphere. On the basis of the radio waves received from space, the first structures of the universe are to be explored in a bid to further the search for extraterrestrial life. Back-lash free over the entire stroke The inclination of each telescope is adjusted to the precise millimetre by the TQS 200 torque screw jack from Pfaff-silberblau. It consists of a prestressed special ball screw, which is actuated free from backlash by a torque motor with a nominal torque of over 100 Nm. The challenges posed by this special development resulted from having to ensure the necessary high rigidity, minimal friction losses and back-lash free adjustment with the best possible efficiency. For instance, it was necessary for the customer to fully ensure prescribed parameters for all the screw jacks, e.g. a low idling torque of less than 60 Nm at maximum speed and to document these accordingly. For a stroke of 750 mm and a lifting speed in an adjustment range of 0.01 to 42 mm/s, the drive moves a load up to 25 kN free from backlash and more precisely than 5 micrometres. For this purpose, a special binary encoder is integrated free from backlash directly on the motor shaft. An emergency brake is connected with positive engagement with all the torque transferring parts. Its braking torque of 310 Nm ensures that the non-self-locking drive is held reliably and safely in all the requested positions.[/b] Resistant in harsh environment[/b] The highly sensitive telescopes are directly exposed to the harsh local weather conditions of this semi-desert region. For this reason, Columbus McKinnon Engineered Products has protected the TQS 200 screw jack with a multi-layer paintwork (C5-M), capable of withstanding the coastal and offshore atmosphere with its high salt content. This means the screw jack is optimally designed for the demanding environmental conditions, being resistant to both condensation and air contamination over a period of decades without impairments. All the transitions, interfaces, cable inlets and outlets as well as the terminal box have been protected by means of a special sealing concept and guarantee the electromagnetic compatibility (EMC). The application and deployment site in the desert call for maintenance-free operation, which can be assured by using a sophisticated roller bearing mounting and the special lubricating grease developed specifically for this application. The requirement for a 30 year service life was exceptionally demanding in this new development. Consequently, all the components and assemblies in the power transmission were designed to ensure long-life fatigue strength. The high durability of the TQS 200 has now also been proven in an endurance test in a Vertex test set-up. Elaborate testing procedure for proving the rigidity To prove that all the specifications had been met, a complete test procedure was developed from scratch and documented in a process sequence specially devised for this. To this end, Columbus McKinnon Engineered Products provided the state materials testing institute for mechanical engineering of the Technical University of Munich with prototypes, which were used to prove the rigidity, i.e. the linear deformation under tensile and compressive loading. This involved exposing worm gear screw jack systems with overall lengths of 1000 mm and 1270 mm to a 10 kN load. Multiple load cycles were examined in the range from 0 to 100 kN for a load change of 1000 N per second. The measurements also comprised a brake test. This entailed supplying current to the drive motor with the brake on until a 310 Nm torque was reached. Further information on worm gear screw jacks of the Pfaff-silberblau brand from Columbus McKinnon Engineered Products is available online at http://www.pfaff-silberblau.com/de-Komponenten-Produkteen-Components-Products/de-Hubelementeen-Screw-Jacks-.html. Further information on the MeerKAT project is available online at http://www.ska.ac.za/.

About Columbus McKinnon Engineered Products Columbus McKinnon Engineered Products GmbH, Kissing/Germany, ranks with its brand Pfaff-silberblau amongst the technology leaders in components and system solutions for mechanical motion and lifting technology. The product portfolio ranges from high quality worm gear screw jacks to powerful lifting tables and rope winches. Based on these components, Columbus McKinnon Engineered Products also offers customer specific solutions for all kinds of applications. Columbus McKinnon Engineered Products GmbH, Kissing/Germany, is a company of the listed Columbus McKinnon Corporation (CMCO), Getzville/USA, a leading designer, manufacturer and marketer of material handling products, systems and services. Worldwide, the corporation has around 3,300 employees at 20 manufacturing facilities in seven countries and in 47 sales and service offices in 21 countries. For more information about Columbus McKinnon Engineered Products and the brand Pfaff-silberblau please visit www.pfaff-silberblau.com.