Posted to News on 17th Jul 2007, 20:54
Thin-section bearings operate at -200 degrees C
R.A. Rodriguez has supplied Kaydon thin-section bearings and engineering analysis for use at cryogenic temperatures on VISTA, a world-class telescope currently under construction.
VISTA (Visible and Infrared Survey Telescope for Astronomy), the world's largest telescope dedicated to ground-based survey work, should be completed by early 2008. Capable of supporting a huge variety of projects from solar-system studies to cosmology, it is equipped with the world's largest infrared camera - and an optical camera can be added later. Design and construction has been managed by the UK Astronomy Technology Centre for a Consortium of 18 UK Universities led by Queen Mary, University of London.
Proposed projects for this world-class telescope range from measuring the galaxy's population of brown dwarf stars to constructing a 3D map that covers about 5 per cent of the entire observable universe.
An important part of the telescope's operation is the exchange of different filters in the field of view to alter the waveband to suit the application. Kaydon bearings were selected for this filter wheel mechanism for the infrared camera, primarily to save space. An ability to operate in a cryogenic atmosphere of -200degC without grease or oil lubrication was also a requirement.
The bearings and engineering analysis were provided to the UK Astronomy Technology Centre by R.A. Rodriguez, the UK factory representative for the Kaydon Corporation. The chosen bearings are of a type that is now said to be considered an industry standard for achieving high performance in a small space. The duplexed pair has a relatively large 7-inch bore but an outside diameter of just 7.5 inches x 0.5 inch high.
Lightweight and lube-free
Also beneficial to the filter wheel mechanism design was the bearings' weight-saving potential. And as the application could not tolerate grease or oil lubrication, these stainless steel angular-contact bearings were supplied with lead ion dry film lubrication.
Sited at the Cerro Paranal Observatory in the Atacama Desert in Chile and operating at an altitude of 2635m, this 4m telescope will become part of the European Southern Observatory's suite of telescopes. Its discoveries will also be crucial in optimising European exploitation of southern hemisphere 8m telescope time.
