The CVPST (Continuously Variable Power Split Transmission) concept is presented in the context of an automotive application. The system consists of a variable pulley system (variator) coupling two of the three rotating elements of a planetary gear train. The main feature of this system is that the variator carries only a fraction of the total power flowing through the transmission, thus increasing the power envelope of the potential engine application. This feature also reduces the power losses associated with power transmission, especially at the low-speed-high-torque modes, while providing continuously variable transmission ratio capability. Supplying the power from electric motor to the control element (countershaft) of the CVPST further reduces the power flowing through the variator. This power (excess of torque) can be used entirely to overcome the acceleration resistance power of the vehicle, so that even during the transient conditions, the working point of the IC Engine is kept all the time, as vehicle accelerates, on the Optimum Efficiency Curve. An Engine Performance Map (EPM) is used to illustrate the vehicle acceleration using electric power, and it can be seen from the diagram how, by proper simultaneous changes in CVPST ratio (R) and opening of the throttle (OT), the efficient and least polluting acceleration of the vehicle can be achieved using the of hybrid system.
Continuously variable power split transmission concept (CVPST) in hybrid vehicles
Stufenloses Konzept zur Leistungsübertragung bei hybriden Fahrzeugen
2000
5 Seiten, 7 Bilder, 5 Quellen
Aufsatz (Konferenz)
Englisch
An automotive continuously variable power split transmission concept (CVPST)
Tema Archiv | 1999
|Power-Split Continuously Variable Transmission Device
Europäisches Patentamt | 2019
|Power-split continuously variable transmission device
Europäisches Patentamt | 2020
|Power-Split Continuously Variable Transmission Device
Europäisches Patentamt | 2019
|Power-split continuously variable transmission device
Europäisches Patentamt | 2020
|