TY - GEN
T1 - Switch-mode continuously variable transmission with flywheel energy storage
AU - Forbes, Tyler D.
AU - Van De Ven, James D.
PY - 2009
Y1 - 2009
N2 - A hybrid drive train significantly improves energy efficiency of ground vehicles. While numerous auxiliary hybrid power sources have been researched, few are capable of the energy and power density of a flywheel coupled with a continuously variable mechanical transmission. The primary challenge of a flywheel hybrid system is a transmission capable of coupling a high speed flywheel to the drive train of the vehicle. A novel solution to this challenge is a switch-mode continuously variable transmission that utilizes a rapidly switching clutch to transmit power. This system, the mechanical analog of a DC-DC boost converter circuit, utilizes a flywheel, a high frequency clutch, an anti-reversing ratchet, and a spring to vary the output torque. The switch-mode continuously variable transmission is demonstrated through an idealized finite difference model, created from the dynamic system of equations. The model is used to demonstrate the system behavior in a passenger car subjected to road loads in various conditions. The output of the model demonstrates pulses in the output torque as a result of the rapidly switching clutch. This output ripple in is smoothed to an acceptable level by the torsion spring. From this preliminary analysis the on-off continuously variable transmission offers an efficient, energy dense, and power dense hybrid vehicle drive train alternative.
AB - A hybrid drive train significantly improves energy efficiency of ground vehicles. While numerous auxiliary hybrid power sources have been researched, few are capable of the energy and power density of a flywheel coupled with a continuously variable mechanical transmission. The primary challenge of a flywheel hybrid system is a transmission capable of coupling a high speed flywheel to the drive train of the vehicle. A novel solution to this challenge is a switch-mode continuously variable transmission that utilizes a rapidly switching clutch to transmit power. This system, the mechanical analog of a DC-DC boost converter circuit, utilizes a flywheel, a high frequency clutch, an anti-reversing ratchet, and a spring to vary the output torque. The switch-mode continuously variable transmission is demonstrated through an idealized finite difference model, created from the dynamic system of equations. The model is used to demonstrate the system behavior in a passenger car subjected to road loads in various conditions. The output of the model demonstrates pulses in the output torque as a result of the rapidly switching clutch. This output ripple in is smoothed to an acceptable level by the torsion spring. From this preliminary analysis the on-off continuously variable transmission offers an efficient, energy dense, and power dense hybrid vehicle drive train alternative.
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U2 - 10.1115/IMECE2008-67685
DO - 10.1115/IMECE2008-67685
M3 - Conference contribution
AN - SCOPUS:70249149345
SN - 9780791848784
T3 - ASME International Mechanical Engineering Congress and Exposition, Proceedings
SP - 329
EP - 336
BT - 2008 Proceedings of ASME International Mechanical Engineering Congress and Exposition, IMECE 2008
T2 - 2008 ASME International Mechanical Engineering Congress and Exposition, IMECE 2008
Y2 - 31 October 2008 through 6 November 2008
ER -