US Patent 7351177 Series of gearboxes

A series of gear systems is disclosed, each of which comprises least one double-shaft, reversible planetary stage including a combination of an open positive gear system having lantern-gear teeth and an output system. “z1” represents the lantern-gear arrangement, and a number of teeth z2 is assigned to at least one planetary gear. The series of gear systems comprises several variants of size categories. Each of the several variants comprises internal gears in which external rollers are seated in grooves such that the intervals are different in the different variants and are produced by the regular elimination of individual external rollers.