Search Results

The objective of this paper is to indicate the design principals of a Continuously Variable Transmission that is physically about the size of a conventional manual transmission for the same power and torque with an equal or better efficiency and durability. The CVT will be designed for use in either a hybrid electric drive or a conventional vehicle with the addition of a torque converter and reverse gear. The design objectives are as follows: 1. About the same size as a 5 or 6 speed manual transmission for North-South engine orientation and rear wheel drive. 2. About the same weight as the 5 or 6 speed manual transmission 3. Cost about the same or less 4. Much smaller than a comparable performance rated automatic transmission 5. Fewer parts than manual transmissions and less than 1/30th of the part count of an automatic. 6. Ratio span greater than equivalent manual or automatic transmissions. 7.

In an effort to improve the Continuously Variable Transmission and evaluate its performance with different modifications, a conventional CVT was redesigned to incorporate an energy efficient Servo Hydraulic Control (SHC) system and to substitute a different torque transmitting element, a Gear Chain Industry (GCI) chain for the Van Doorne Transmissie (VDT/Bosch) belt. Various loaded and unloaded tests were performed on the CVT while using the GCI Chain and VDT Belt in the Stock and Servo Hydraulic configuration. An analysis of the various configurations was made and key features of each element have been outlined.

The objective of the advanced transmission system concepts such as the Continuously Variable Transmission (CVT) and Hybrid Electric Drives is to improve fuel efficiency, lower emissions and reduce powertrain part count while not impacting cost. The control of the system, however, can greatly affect the final fuel consumption, performance and emissions for any of the possible configurations. This paper describes an engine control philosophy for a hybrid electric CVT powertrain concept with the fewest number of mechanical parts but with many modes of operation such as: 1. All electric operation 2. Regenerative braking to maintain the battery charge at a desired level. 3. Engine charge for maintaining the battery state of charge 4. Highway cruise efficiency. 5. Power enhancement by use of the electrical energy for passing and highway maneuvers. 6.