The annealing furnace at a Pennsylvania metal manufacturer had an interior temperature in the range of 1200°F (650°C). Bearings supporting the pinch rolls were located outside the furnace walls and reached temperatures up to 750°F (400°C) due to heat transmitted through the furnace wall by the shaft.
The heat transmitted by the shaft through the oven wall to the
bearing was causing lubrication failure. In addition, the movement
(linear expansion) of the shaft caused problems well beyond the
capability of any standard ball or roller bearing arrangement.
GRAPHALLOY ® high temperature bearings were installed in a metal
adapter designed to fit the original bearing housings and solved the
problem without a major redesign. With minimal investment, bearings
failures and associated maintenance costs were reduced.