A Continuously Variable Power Split Transmission for Automotive Applications 970687
Continuously variable transmissions, commonly known as CVT's, have been shown to be feasible alternatives to the conventional multi-step gear transmissions (standard or automatic) typically used in automotive applications. Most CVT applications, however, rely on a shaft-to-shaft transmission arrangement, in which the belt-sheave action limits the load capacity of the transmission, particularly at the high power ranges (low speed, high torque).
In this paper, a system based on a combined planetary gear train and a continuously variable pulley system is presented. The uniqueness of this arrangement is that the variable pulleys provide a power/torque split and recirculation function, which, when combined with the planetary gear train function, produces a continuously variable power split transmission system. The CVT ratio (r) is used as the regulator of the overall transmission ratio (R), in such a way that at low speeds, the power circulating through the belt can be only a fraction (less than 50%) of the total input power. Then, as the continuous shift is made to the high speed range, the power circulation shifts towards the CVT unit, a much desired feature in automotive applications.
Citation: Mucino, V., Smith, J., Cowan, B., and Kmicikiewicz, M., "A Continuously Variable Power Split Transmission for Automotive Applications," SAE Technical Paper 970687, 1997, https://doi.org/10.4271/970687. Download Citation
Author(s):
Victor H. Mucino, James E. Smith, Ben Cowan, Marek Kmicikiewicz
Affiliated:
West Virginia Univ., CK Engineering
Pages: 8
Event:
SAE International Congress and Exposition
ISSN:
0148-7191
e-ISSN:
2688-3627
Also in:
Electronic Transmission Controls-PT-79, 1997 Transmission and Driveline Systems Symposium: Transmission Systems, Components, Gears and Friction and Fluid Materials-SP-1241
Related Topics:
Continuously variable transmissions
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