Gear drive for rotary furnace - uses idler pinion to reduce hertz stresses in ring gear

摘要

The gear drive to a rotary furance consists of a driving pinion (1) meshing with an idler pinion (3) which, in turn, meshes with the toothed ring (2) of the furnace. The diameter of the idler pinion (3) is three times that of the driving pinion. The toothed ring (2), because of its large size, cannot be heat treated to increase its surface hardness and so it cannot withstand high Hertzian streses. Since he Hertzian stresses vary inversely as the diameter of the idler pinion (3) the stress is reduced by using a pinion of relatively large diameter. The width of the toothed ring (2) can thus be reduced with a consequent reduction in manufacturing cost.