Drives stand the test of time
By Maryanne BronsonMachinery and Equipment Maintenance
Over two decades ago, a big research lab required drives that were compact, could produce extremely slow travel speeds, would withstand ongoing exposure to radiation and would need little maintenance. All this was necessary so the lab could...
Over two decades ago, a big research lab required drives that were compact, could produce extremely slow travel speeds, would withstand ongoing exposure to radiation and would need little maintenance. All this was necessary so the lab could study quarks and gluons – certainly an unusual and highly specialized application for industrial drives.
The drives were supplied to Thomas Jefferson National Accelerator Facility in Newport News, VA, also known simply as the Jefferson Lab. It’s a world-leading nuclear physics research facility funded by the US Department of Energy. It is devoted to studying the building blocks of matter.
International and US-based scientists use the lab’s Continuous Electron Beam Accelerator Facility (CEBAF) to probe the nucleus of the atom and study subatomic particles known as quarks and gluons. Like a giant microscope, CEBAF propels an electron beam at nearly the speed of light into targets located in the lab’s three experimental halls. When the beam strikes a target, the interactions are recorded and studied.
In 1987, when design and construction of this US$600-million facility began, Sumitomo drives were specified for every critical application requiring drives and controllers, including the levelling jacks that were designed to compensate for possible settling of the one-million-pound structure once it was moved into position, the Shield House Carriage Wheel Assembly, and the Spectrometer Support Structure Wheel Assembly.
The structure’s enormous size required extremely slow travel speeds, and compact drives were essential because the wheel drives were mounted directly on each wheel assembly.
Additional requirements included withstanding extended periods of radiation and providing relatively trouble-free service for a minimum of 20 years.
These applications required high reduction ratios in a compact, durable, low-maintenance package. Sumitomo’s Cyclo drives offered all these features, as well as grease lubrication, which would enable them to withstand radiation exposure better than oil-lubricated drives. For these reasons, Jefferson Lab designers and engineers determined that Cyclo was “really the only choice.”
The Spectrometer Support Structure and Shield House are supported by wheel assemblies that ride on curved tracks anchored to the concrete floor. Sumitomo adjustable frequency AC drives enable the entire structure to be precisely positioned.
More than 20 years later, the Jefferson Lab is building a new experimental research building and upgrading equipment in the three existing experimental halls. During the renovation of Experimental Halls A and C, it extended an invitation to a small group of employees from Sumitomo and industrial distributor Applied Industrial Technologies to tour the facility and see first-hand how well the drives had performed.
At the start of the tour, senior engineer Paul Brindza reported that Sumitomo’s drives had exceeded expectations. “They have been extremely reliable and accurate,” he said. During the three-hour tour, Brindza commented several times that the Cyclo drives had withstood exposure to radiation very well, were very low maintenance, and operated virtually trouble-free.
As a result of the drives’ reliability and performance, the Jefferson Lab planned to once again specify the same drives for its new expansion and renovation project.
For more information, visit the website at www.suminet.com.