1. Performance analysis of the Impulse Shift CVT Roëll van Druten Bas Vroemen Alex Serrarens Michiel Pesgens Drivetrain Innovations BV The Netherlands www.dtinnovations.nl

2. Outline Zero Inertia (ZI) ZI & Impulse Shift Drivetrain model Performance results Agility criteria & results Conclusions

3. Zero Inertia project engine CVT planetary set inertia wheel 1997 2002 2004 goal: eliminate jet start behaviour Impulse Shift development

4. Zero Inertia principle overdrive low V flywheel V vehicle V engine overdrive 4000 rpm @80kph

5. Zero Inertia principle overdrive low V flywheel V vehicle V engine low zero speed

6. Modular Construction

7. Zero Inertia test results Improved pedal-in and pedal-out response (no jet start behaviour) Very comfortable cruising 22% fuel saving @120kph

8. Further development targets Reduce inertia size and weight Integration into transmission Additional functionality

9. ZI & Impulse Shift ZI down shift power through CVT becomes zero Impulse Shift (IS) decouple variator

10. Drivetrain layout 3.3L V6 engine 50% reduced inertia size torque converter DNR clutch

11. Expected benefits of IS principle 1.faster flywheel speed down gives immediate inertia-assist 2.faster engine speed up enables quick engine power availability 3.1&2 enable further downsizing of flywheel inertia 4.no additional controls using drive clutch (DNR)

12. Drivetrain model

13. Impulse Shift simulation results 0.811.21.41.61.822.22.42.6 -0.5 0 0.5 1 1.5 2 2.5 3 time [s] vehicle acceleration [m/s 2 ] IS ZI CVT

14. Flywheel power assist 0246810 -30 -20 -10 0 10 20 30 40 50 60 time [s] flywheel power [kW] ZI IS

15. Vehicle leads matched for IS and ‘comfort-mode’ CVT 0123456 0 1 2 3 4 5 6 time [s] vehicle lead w.r.t. CVT [m] ZI baseline: CVT from 1350 rpm CVT from 2200 rpm IS

16. Comparison IS-CVT and comfort mode CVT engine speed while cruising @80 kph: 1350 rpm for IS-CVT 2200 rpm for comfort-mode CVT comfort mode CVT uses 15% more fuel than IS- CVT @80 kph IS-CVT and comfort mode CVT have similar performance

17. Agility criteria (Frei et al. 2004)

18. ‘pI’ mean(dTq/dt)

19. Agility results invert 80-120 km/h: CVT: 5.9 s ZI: 5.7 s IS: 5.4 s CVT-C: 5.4 s

20. Conclusions Impulse Shift (IS) adds substantial kickdown performance to Zero Inertia (ZI) without extra components or actuators Agility of ZI-CVT comparable to ‘comfort- mode’ CVT while saving 13% fuel @80 kph Agility of IS-CVT superior to ‘comfort-mode’ CVT while saving 13% of fuel Future work...

21. Transmission integration  flywheel wrapped around torque converter  50% reduction in flywheel inertia  planetary gear integrated with DNR  drive clutch = Impulse Shift actuator Zero Inertia evolution