Just re-discovered something from some of my old magazines that my mom brought by earlier today all of us here in the 4x4 community might be interested in. Couldn't find the pictures printed in the original article on the 'net, so I took pictures of the cover and original magazine instead. Rotary Face And Pinion Gear Set, Magazine Cover Rotary Face And Pinion Gear Set, Integrated Into A Solid Truck Axle Here's the text from the original magazine article: Designed by: Fred L. Vreeman Orlando, FL The low-friction gear set operates with high efficiency over the entire range of power transmission capability. The gear tooth is a rotating stud that rolls along the thread path of a cylindrical pinion, eliminating the metal contact "sliding friction" typical with conventional gears. Dynamometer tests on this type of device show dramatic efficiency gains over conventional gears, especially in the acceleration and deceleration (high torque) parts of the power curves. Applied to electric vehicles, the gears have resulted in up to 40% more range. Previous attempts to design and produce rotary gears resuited in complex double enveloping designs that were difficult and expensive to manufacture. Several designs include hourglass-shaped worms with enveloping gears carrying radial and angled rotary gear teeth. These require extremely tight tolerances held on all axes for the gear set to operate. By applying published formulas and methods for designing face gears and face worms, it is possible to build the device presented here. A property designed involute profile on the rotary gear tooth and the rotary pinion path eliminates the need for a double enveloping gear, and thus, eliminates much of the gear's complexity. A "face gear" is a simpler design than the double enveloping worm. It allows use of larger bearings on the rotating gear teeth and the positioning of the cylindrical pinion (worm) is exponentially less critical. Inexpensively produced roller bearings can now be used. The pinion fabrication is much less expensive. Most of the other components can be produced with conventional manufacturing devices. The simpler design, with less stringent tolerances, will allow manufacture of this device in low and high quantities at costs that are competitive with the gear sets it will replace. The gear pictured is an 18:1 reduction designed around a conventional differential for an electric utility vehicle. It incorporates an additional novel "anti-backlash" feature that improves performance and allows less stringent tolerances in fabrication of the pinion. The components can be fabricated on a 4-axis CNC mill and a CNC lathe. Gear mesh surfaces are heat-treated and finish ground, and optionally, chromed. The housing would be sand cast initially and later re-designed to die cast for volume production. Different ratios could be produced in the same size. Many different materials could be used for the components. The OEM market buys approximately 4 million small reduction differentials per year in golf, utility, and small electric vehicles. Most are twin helical sets. Rotary gears can have higher reduction ratios with a single gear set (similar to a worm gear), allowing higher-speed, smaller, lighter, and more efficient motors to be used in applications. Unlike worm gears, rotary gears can be back-driven and used as speed increasers for high-speed, lightweight generators or turbine pumps. This has obvious marine propulsion, water pump, and generator applications. Wind generators will function in 4-MPH winds with these gears instead of 7-MPH with conventional gears. 18:1 axle gears possible with this!!! Problems I see with this is that this would only be really useful on a trail-only vehicle, and we'd probably have to start putting smaller engines maybe in our rigs then. But, on the upside, we could either eliminate some of the gearing we're putting in our transmissions and transfer cases, or be able to get INSANELY low gearing, but maybe at the cost of really breaking parts faster than we can say "WTF?" What do you guys think of this?