NEW CONTINUOUSLY VARIABLE TRANSMISSION
Inventor develops most versatile transmission Technology is durable, affordable, simple; Floating Sprocket Bars would improve some existing transmissions, including Variable Diameter Pulley CVTs For the first time, a continuously variable transmission (CVT) has been developed that is practical, durable and cost-effective. The Anderson A+CVT promises to dramatically reduce fuel consumption by enabling vehicles to function at their optimum gear ratio, regardless of load, incline and other driving conditions. Unlike other CVTs now on the market, the Anderson A+CVT can be scaled to any size vehicle, including bicycles, automobiles, trucks and heavy construction and military equipment. Equally significant is the fact that, unlike other CVTs, the Anderson A+CVT is POSITIVE-DRIVE, rather than friction-dependent. This means that it will last longer, and can operate more efficiently. For decades, the automotive industry has tried unsuccessfully to develop such a transmission. Patents have been issued for several designs, some of which have been manufactured and marketed. However, all have had problems that rendered them impractical for dependable, everyday use except in small vehicles. The Anderson A+CVT has no such limitations. The Anderson A+CVT utilizes a well-known principal of two parallel cones positioned with the large end of each cone opposite the small end of the other. What makes the Anderson A+CVT unique is an innovative feature called Floating Sprocket Bars (FSBs). FSBs are positioned in longitudinal grooves around the perimeter of each cone. The distance between the sprocket bars increases as they diverge from the smaller end of the cone to the larger end, and conversely the distance decreases as they converge from the larger end to the smaller end. The bars are designed to pivot slightly with a limited freedom for circumferential movement away from and back to their home position. This floating action permits the uniformly spaced chain links to mesh with the sprocket bars at any point along the longitudinal surface of the cones, regardless of the difference in distance between the bars at any point. It should be noted that with straight-tapered cones, the total required chain length varies as the chain is moved from the center position to the end positions. Since the chain cannot be stretched, this would result in a need for slack in the chain. The Anderson A+CVT solves this problem by using multitapered cones which have a constant required total chain length along the entire distance of the chain travel. The chain is moved from one position to another by an actuator, which simply pushes the chain in the desired direction. The gear ratio change is a smooth stepless transition from lower to higher, and from higher to lower speeds. The result is a long-lasting transmission that can adjust its gear ratio by as much, or as little as necessary, to enable a vehicle to operate at its optimum level of efficiency, under any driving conditions. "Most automobile engines offer a limited number of speeds, or gear ratios," explains Anderson. "Engines are seldom operating at peak efficiency in any of the 'fixed' gear ratios. Small differences in gear ratios can significantly affect fuel consumption. The Anderson A+CVT can find an infinite number of speed ratios within its design range to find the optimum position for maximizing fuel economy. The speed range - lowest to highest gear - can be designed as wide as desired for any vehicle." HOW FSBs CAN GREATLY IMPROVE VARIABLE DIAMETER PULLEY CVTs Some automobile manufacturers, including Audi, Nissan, Toyota and Saturn have begun using a new kind of transmission known as a Variable Diameter Pulley CVT in selected vehicles. However, because of inherent design limitations, these transmissions are prone to wear because they are friction-dependent. The Floating Sprocket Bar (FSB) technology of the Anderson A+CVT could significantly improve existing Variable Diameter Pulleys (VDPs) because Floating Sprocket Bars are not friction-dependent! With VDPs that are now on the market, a drive belt winds around two pulleys. On each pulley, the flanges move laterally away from and, alternately, closer to each other. As the flanges separate from each other, parallel to the axis, the V-shaped space between them widens, enabling the belt to slide closer to the axis. As the flanges move closer together, closing the V-shaped gap, the chain or belt is forced toward the outer perimeter of the pulley. The change in position of the chain or belt results in varying gear ratios. The problem is that, in order to drive the pulley, the drive belt must constantly rub against the inside of each flange. In order to prevent slippage, these units require sophisticated high pressure control systems, which are expensive to produce. Furthermore, the resulting friction will eventually cause the unit to wear out. Friction also limits the load capacity of such a design. The chain or belt used in existing friction-dependent VDPs cannot be lubricated, since the purpose of lubrication is to reduce friction. All of these problems can easily be overcome by adapting the Floating Sprocket Bar (FSB) technology of the Anderson A+CVT. Here is how: The FSBs would be mounted radially on the inside of the flanges of each pulley. A specially designed beaded chain or a flat belt with projections along the sides would wind around the pulleys, engaging the FSBs at a point, with minimal surface contact. This concept makes the VDP a positive-drive transmission, as opposed to a friction-dependent system. Since the VDP would no longer depend on friction to drive the pulleys, the system would be lubricated, which will reduce the wear on the unit and prolong its service life. Unlike existing CVTs, this design could easily be scaled to larger and heavier vehicles. A further advantage of applying A+CVT technology to existing VDP designs is simplicity. Mechanically, A+CVT technology is much simpler, and would cost no more to produce than existing transmissions. In fact, it is likely that A+CVT technology would make VDPs less costly to produce. For example, the Floating Sprocket Bars (FSBs) would make extremely high pressure against the pulleys unnecessary. This would eliminate the need for the complicated hydraulic components currently used to control the lateral movement of the pulley flanges. Advantages of using A+CVT technology in either a "dual cone" design or a Variable Diameter Pulley transmission are: § Simple and less expensive § Positive-drive, not friction-dependent § Can be lubricated § Longer-lasting § Can be scaled to any vehicle It took Lawrence Anderson five years to develop the Anderson A+CVT. It is currently under industry review. U.S. and foreign patents are pending. <A HREF="http://www.andersoncvt.com/">www.andersoncvt.com</A>