Posted to News on 13th Aug 2020, 10:00
Schaeffler direct drive motor brings intergalactic advantages
Schaeffler has provided a rotating direct drive motor solution for operating a giant telescope located on La Palma in the Canary Islands. It is one of the world's largest reflecting telescopes, providing astronomers and astrophysicists alike with a high performance platform to closely observe distant galaxies. The location at the Roque de los Muchachos ridge on La Palma, (which rises to a height of almost 2,500 metres) offers professional stargazers ideal research conditions thanks to the Atlantic island's extremely low levels of light pollution.
The Gran Telescopio de Canarias (GTC) has 36 reflectors and a diameter of 10.4m, and the silver-coloured steel structure is one of the world's largest reflecting telescopes. The GTC, which was opened in 2009 at a cost of 80 million euros, weighs around 300 tonnes and has already spotted more than 2,000 planets and discovered galaxies far away. For obvious reasons giant telescopes such as the GTC must operate with extremely high precision. Scientists observing the stars at night or in the early hours of the morning rely on long exposure times, which means the telescope must be able to move with millimetre precision - a challenging task given the mass involved.
Drawing on previous experience in the field (Schaeffler had already supplied a torque motor for a satellite observation station in Changchun, China, which is part of the National Astronomical Observatories belonging to the Chinese Academy of Sciences), Schaeffler Iberia was involved in developing an instrument rotator for one of the GTC's focal stations, known as the Cassegrain Focal Station (CG-Set). IDOM, a Spanish company that provides engineering and architecture services, was commissioned to develop this new CG set. Due to its previous positive experience with Schaeffler Iberia on various projects, IDOM chose Schaeffler as its partner in the development of the instrument rotator drive.
The instrument rotator is a high-precision mechanism and controls the focal tracking and rapid positioning system that rotates the two-tonne telescopic camera: Schaeffler's drive solution not only had to ensure the system's ability to precisely position the camera and regulate its speed, but also had to feature a compact, lightweight instrument rotator as well. To this end, the company devised and developed a segmented, slotless RMF torque motor for the drive of the instrument rotator. Assistance was also provided by Schaeffler during the mounting process in order to determine the motor's control parameters. The direct drive from Schaeffler Industrial Drives is characterised by its dynamic yet even motion and high energy efficiency. The special motor, which is more than two metres in diameter, was developed and built based on a proven drive concept used in machine tools for grinding operations.
This system also offered other advantages; for example, the segmented design of the motor reduced the costs of transportation and mounting. Further, the relatively compact design facilitated the installation process, and optimised the overall system performance and maintenance. A particularly important advantage was that only the affected segment - rather than the entire motor - could be replaced when servicing is required.
Learn more about Schaeffler's products and services at www.schaeffler.co.uk.
