A novel principle for automatic transmission

This paper unveils a new principle for automatic transmission, which may greatly simplify the current automatic transmissions and improve their efficiency. Unlike traditional automatic transmission based on torque converter/planetary gears, automatic transmission systems based on V-belt variable speed drive, or traditional transmission with electrical control, this new approach does not rely on the gear ratio or radii of the driving and driven wheel to change the speed ratio. The speed change in the new approach is achieved by an elastic belt on two fixed-diameter pulleys. The belt elongates in proportion to the load applied, and the driving pulley of fixed diameter has to rotate more to accommodate the increased length of the belt due to the load increase, consequently reduces the speed of driven pulley. This self-sensing, self-adjusting, and fully automatic drive system is pure mechanical without the need of electrical or hydraulic control. Based on this novel kinematic principle, the simplest automatic transmission in the world may be designed, manufactured, and used.Copyright © 2007 by ASME