High temp. fan for self cleaning oven - has indentations on circumference of disc to prevent temp. stresses

摘要

The self cleaning oven for a domestic cooker has a centrifugal fan for circulating air which has to operate at very high temperatures. The fan has a circular disc (1) with a strengthened or reinforced central hub (2). Sections of angle (3, 4) are attached to the disc running radially along it to form projecting radial blades (4). The circumference (5) of the disc is stamped out to form a series of indentations (6) having a smooth rounded contour. These can expand at the very high temperatures to which the disc is subjected to prevent temperature sresses in the disc which would distort it and cause permanent damage.