This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Efficiency Optimization of the Pushbelt CVT
Technical Paper
2007-01-1457
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
The efforts to further reduce fuel consumption of vehicles equipped with a pushbelt type Continuously Variable Transmission (CVT) focus on different sources of loss. In this paper the magnitude of these losses and their potential for reduction is described.
Inside the CVT, the variator, its control strategy and the hydraulic actuation circuit can be distinguished as the main potentials. A major opportunity is offered by a new control strategy that takes the actual slip between belt and pulley as the control parameter. The resulting decrease of clamping forces on the pushbelt leads to a reduction of variator and actuation losses. Further potential is found in the hydraulic actuation circuit by an improved tuning of the power supply to the actual power requirement. Outside the CVT additional potential is found in start-stop functionality as supported by measures inside the transmission.
The paper describes the theoretical background as well as practical fuel savings of up to 5.5% that were obtained in tests on vehicle level. Slip control adds an inherent robustness to the operation of the pushbelt and opens up the fuel saving potential of the CVT thus reinforcing its position as a state of the art transmission technology.
Recommended Content
Authors
Citation
van der Sluis, F., van Dongen, T., van Spijk, G., van der velde, A. et al., "Efficiency Optimization of the Pushbelt CVT," SAE Technical Paper 2007-01-1457, 2007, https://doi.org/10.4271/2007-01-1457.Also In
References
- Van Schaik Marco “New Phase 7 pushbelt design to cover all FWD applications” CTI congress Paris 2005
- Ishida Shigeo “Recent innovations in transmission development” Keynote presentation 4 th CTI congress Berlin 2005
- Maeder Klaus-Martin “Continuously Variable Transmission: benchmark, status and potentials” Keynote presentation 4 th CTI congress Berlin 2005
- Yamamoto Masahiro et al. “Hydraulic system, shift and lock-up clutch controls developed for a large torque capacity CVT” paper 04CVT-07, CVT congress 2004
- Ohashi et al. “Development of high-efficiency CVT for luxury compact vehicle” SAE paper 2005-01-1019 , SAE 2005
- Sluis van der “A new pump for CVT applications” SAE paper 2003-01-3207 2003
- Sue Armin “Betriebsverhalten stufenloser Umschlingungsgetrieben unter Einfluss von Kippspiel und Verformungen” Dissertation University of Hannover 2003
- Masabumi Nishigaya et al. “Development of Toyota's ‘New Super CVT’” SAE paper 2001-01-0872 , SAE 2001
- Schultheiß et al. “Torque fuse Regelung der Abtriebskupplung eines CVT” VDI Bericht 1917 287 305 2005
- van der Laan et al. “Improving pushbelt efficiency by control strategies based on new variator wear insight” paper 04CVT-039, CVT congress 2004
- Veenhuizen et al. “Variator slip control implemented in a production vehicle with pushbelt CVT” 3rd CTI congress Würzburg 2004
- Takahara et al. “CVT control system for Toyota intelligent idling stop system” SAE paper 2004-01-1635 , SAE 2004
- Tsukuda et al. “Toyota new belt CVT for 1.3 ltr FWD cars” SAE paper 2006-01-1305 , SAE 2006
- van der Sluis et al. “Fuel economy potential of the pushbelt CVT” Fisita 2006 Yokohama