Zero transmission error gearing

Abstract

The usual expedient employed by gear designers seeking to reduce gear noise at all loads has been to specify finer teeth, which in effect trades away torgue capacity for quietness. The present disclosure describes a tooth form that substantially eliminates gear noise while at the same time significantly increasing torque capacity. This tooth form involves (a) the synchronization of the loading and unloading phases of tooth engagement with the inverse phases (i.e., unloading and loading phases, respectively) of another tooth pair, combined with (b) the introduction of particular patterns of topographic tooth surface crowning that transform the elastic tooth pair stiffness curve into a curve that not only maintains this synchronization at loads greater or smaller than the design load but also eliminates transmission error to any extent desired. As neither feature (a) nor (b) requires fine teeth, the tooth form may be employed with any number of teeth, and this allows specification of the "critical tooth number" that maximizes torque capacity.

Dependencies are inferred from the claim text.