Translator Disclaimer
17 September 2007 Design of asymmetrically loaded end-plates with vacuum seal surfaces for the Navy Prototype Optical Interferometer
Author Affiliations +
Engineering specifications for O-ring seal surfaces are well documented. However, when seal surfaces are located on asymmetrically loaded vacuum end-plates, consideration must be given not only to surface finish and flatness, but also to load-induced deflections. When deflections are significant, O-ring compression can relax and potentially cause vacuum leaks. Large vacuum systems, such as the 9000 cubic foot system at the Navy Prototype Optical Interferometer (NPOI), cannot afford costly vacuum leaks due to improper end-plate design. The NPOI employs vacuum end-plates that serve both as structural members, and as vacuum system entrance and exit ports for stellar light. These ports consist of vacuum components attached directly to the end-plate via static O-ring sealing techniques. Optical geometry dictates off-center port locations, which create asymmetric end-plate loading. This paper details the behavior of a 22 inch diameter, multi-port, end-plate for the NPOI Fast Delay Line subsystem. In depth CAD modeling and finite element analysis techniques were used to determine load-induced stress distributions and deflections in the end-plate. After several design iterations, an end-plate design was substantiated that maintains vacuum seal integrity under loading, exhibits a conservative factor of safety, and is readily manufacturable.
© (2007) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Joshua P. Walton, James H. Clark III, and F. Ernesto Penado "Design of asymmetrically loaded end-plates with vacuum seal surfaces for the Navy Prototype Optical Interferometer", Proc. SPIE 6665, New Developments in Optomechanics, 666513 (17 September 2007);


Superpolished OAPs for WFIRST CGI
Proceedings of SPIE (July 30 2018)
Machine accuracy for rapid prototyping of quality components
Proceedings of SPIE (October 09 1998)
Engineered damping treatments
Proceedings of SPIE (July 02 2001)
Use of 3D printing in astronomical mirror fabrication
Proceedings of SPIE (April 20 2020)
Mirror deformation versus contact area in mounted flat mirrors
Proceedings of SPIE (September 10 2009)

Back to Top