Transcript PowerPoint-presentatie

Performance analysis
of the Impulse Shift CVT
Roëll van Druten
Bas Vroemen
Alex Serrarens
Michiel Pesgens
Drivetrain Innovations BV
The Netherlands
www.dtinnovations.nl
Outline
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Zero Inertia (ZI)
ZI & Impulse Shift
Drivetrain model
Performance results
Agility criteria & results
Conclusions
Zero Inertia project
goal: eliminate jet start behaviour
engine
planetary set
inertia
CVT
wheel
1997
Impulse Shift
development
2002
2004
Zero Inertia principle
Vengine
4000 rpm
@80kph
Vvehicle
low
overdrive
overdrive
Vflywheel
Zero Inertia principle
Vengine
zero speed
Vvehicle
low
low
overdrive
Vflywheel
Modular Construction
Zero Inertia test results
• Improved pedal-in
and pedal-out response
(no jet start behaviour)
• Very comfortable cruising
• 22% fuel saving @120kph
Further development targets
• Reduce inertia size and weight
• Integration into transmission
• Additional functionality
ZI & Impulse Shift
power through CVT becomes zero
decouple variator
ZI down shift
Impulse Shift (IS)
Drivetrain layout
50% reduced inertia size
3.3L V6
engine
torque converter
DNR clutch
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)
Drivetrain model
Impulse Shift simulation results
3
2.5
vehicle acceleration [m/s
2
]
IS
2
1.5
ZI
CVT
1
0.5
0
-0.5
0.8
1
1.2
1.4
1.6
1.8
time [s]
2
2.2
2.4
2.6
Flywheel power assist
60
IS
50
flywheel power [kW]
40
30
20
ZI
10
0
-10
-20
-30
0
2
4
6
time [s]
8
10
Vehicle leads matched for IS and ‘comfort-mode’ CVT
6
vehicle lead w.r.t. CVT [m]
5
4
3
IS
2
ZI
CVT from
2200 rpm
1
0
baseline: CVT from 1350 rpm
-1
0
1
2
3
time [s]
4
5
6
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 ISCVT @80 kph
• IS-CVT and comfort mode CVT have similar
performance
Agility criteria (Frei et al. 2004)
Agility criteria (Frei et al. 2004)
‘pI’
mean(dTq/dt)
Agility results
12
10
invert
8
CVT
ZI
6
IS
CVT comf.
4
2
0
perf. 1
comfort 1
comfort 2
80-120
CVT
ZI
IS
CVT-C
km/h:
: 5.9 s
: 5.7 s
: 5.4 s
: 5.4 s
Conclusions
• Impulse Shift (IS) adds substantial kickdown
performance to Zero Inertia (ZI) without extra
components or actuators
• Agility of ZI-CVT comparable to ‘comfortmode’ CVT while saving 13% fuel @80 kph
• Agility of IS-CVT superior to ‘comfort-mode’
CVT while saving 13% of fuel
• Future work...
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