Face gears typically have a straight or skewed tooth line and varying tooth profile in normal cross section
at different radii from major to minor diameter. These face gears are engaged with spur or helical involute
pinions at intersecting or crossed axes.
This paper presents spiral face gears with an involute tooth line and an identical tooth profile in the
normal section at any radius. There are two main applications for such face gears. One of them is an
alternative solution with certain advantages in performance and fabrication technology to the straight
tooth, Hirth, or Curvic flange couplings. Another application is when a face gear is engaged with an
involute helical pinion or worm at intersecting or crossed axes.
Potential advantages of spiral face couplings and gears include high power transmission density and
highly productive machining of face spiral gears.
The paper describes gear geometry analysis, and design technique of spiral face involute gears with
symmetric and asymmetric tooth profiles. It also explains a hobbing method of these gears and tool
design specifics, and then illustrates gear and tool design with numerical examples.