|PBC Linear, www.pacific-bearing.com|
When a nuclear plant needed its fuel rods changed, technicians had to unbolt all 54 of the 700-lb studs securing the reactor-vessel head. The studs were painstakingly placed in square racks that constantly needed to be repositioned under the crane that removed and transferred the studs, a time-consuming and risky process. To simplify the task, engineers at Quality Engineered Products, Holden, Maine, built a stud rack modeled after a lazy Susan. The 42-in.-diameter rack could be manually turned to accept new studs and did not need to be repositioned as the crane moved. One key to the success of the new rack was Hevi-rail heavyduty linear and axial bearings from PBC Linear, Roscoe, Ill. They let the rack rotate smoothly and could easily support the weight of nine reactor studs. Once in use, the new lazy-Susan rack halved the time needed to remove and replace studs, letting the plant go back on line much sooner.