WHEN PINIONS OF SMALL TOOTH NUMBERS ARE REQUIRED FOR SUCH APPLICATIONS AS MOTOR STARTING PINIONS OR LARGER REDUCTION RATIOS IN A SINGLE REDUCTION, UNDERCUT MAY BE MINIMIZED AND AN EFFECTIVE DRIVE ...

In principle, the design of internal gear teeth is the same as that for spur gears. Any of the basic rack forms used for spur gears may be applied to internal gears. The internal gear drive, however, ...