the transmission’s role in hybrid vehicles · of wet double clutch amt has 4% of fuel economy ......
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Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reservedinspire • innovate • drive
THE TRANSMISSION’S ROLE IN HYBRID VEHICLESMarco Fracchia | 25 February 2016
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
Vocis Ltd.An Introduction
“Pioneers in the development of innovative automotive transmissions
and their control systems”
Foremost specialists in transmissions, drivelines and
their control systems, with a Worldwide portfolio
Founded in 2006, with a team of circa 30 distinctly
skilled, highly experienced staff
51% owned by Oerlikon Graziano, a tier 1 supplier of
gearing and shifting solutions, and transaxles for high
performance cars
An independent dynamic business with larger company
backing, ISO9001 accredited, and a business turnover
the envy of many larger companies
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
The Transmission’s Roles and Responsibilities – Do we need one?
‘Something’ is needed to provide connection
between traction device and wheels
Is one gear enough?
� YES ?
� if the traction device is adequately capable
of delivering torque at high efficiency over
the required operating speed range of the
vehicle
� NO ?
� if the traction device cannot provide suitable torque at
wheels over the vehicle speed range
� If the system efficiency can be substantially improved
with multiple gears
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
The Transmission’s Roles and Responsibilities – Do we need one?
‘Something’ is needed to provide connection
between traction device and wheels
Is a launch device required?
� YES ?
� If the traction device cannot provide
smooth pullaway from zero speed
� NO ?
� If the traction device can provide smooth
pullaway from zero speed
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
Complexity: The Required Attributes
� For the North America and
European markets efficiencyand performance are the
strongest drivers
� The overall picture though
shows that the drivers are
balanced to include comfort
and weight
� Cost sensitivity is shown as
most significant in South
America and Asia
� Historically the transmission
has been significantly less
expensive than other
powertrain components
Cost
� Piece Price
� Complexity
� Modularity
Comfort
� Shift Quality
� Drivability
� NVH
Efficiency
� Ratio Spread
� Mechanical Simplicity
� Low loss actuation
Performance
� Launch
� Acceleration
� Sporty
Character
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
Complexity: The Balance of Attributes
� The transmission, then, is utilised to provide the best overall compromise for the key
attributes:
� Simplicity helps:
� Cost (<10% of total powertrain)
� Efficiency (typically >95%)
� Weight reduction
� Complexity helps:
� Comfort (shift comfort, NVH)
� Performance (launch, acceleration)
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
Complexity: Increased Integration
First manual
transmissions
(MT)
Torque /Speed
interface between
TCU/ ECU
1930s1900s 1986 1996
First Automatic
Transmissions (AT)
3- & 4- speed
CAN communication
protocol officially
released
Holistic approach for hybrid
powertrains
Powertrain Controllers
“Distributed Computing”
2020 ����
First Active Yaw Control
(Active differential)
Interfacing to vehicle
dynamic systems
Instrument Cluster
Communication
1990s
• ‘Bolted’ to engine
• No vehicle communications
• ATs are hydromechanical
units
• Powertrain considered as
a whole
• Functions fully integrated
INCREASING INTEGRATION
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
Complexity: Trend of Increased Electrification
� Legislation limits and
acceptance of hybrid
technologies are driving
higher electrification of
vehicles, in ever
increasing volumes
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
Modular Dedicated
Modular vs. Dedicated Hybrid Transmission Systems
Advantages:
� Simplified mechanical
arrangement
� Optimised for complete
system
� Simpler packaging
� Lower production cost
e.g. VW DQ400e
Source: GreenCarCongress
e.g. GM Voltec
Source: GreenCarReports
Advantages:
� Lower development cost
� Modularity with non-
hybrid derivatives
� Appropriate for low
volumes
Disadvantages:
� Complex
� Not optimised for efficiency
� Heavy
� More difficult to package
� Expensive production cost 2020 ����
Disadvantages:
� No modularity with non-
hybrid derivatives
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
AVL 8-mode Renault-Nissan ZE Eolab GKN Multimode
Dedicated Hybrid Transmission Systems:Sample of Wide Variety of Architectures
8-mode Dedicated Hybrid Transmission
M.Yolga, AVL
14th CTI Symposium Berlin 08/12/2015
ZE Eolab Hybrid Powertrain
A.Vignon & N.Fremau, Renault-Nissan
14th CTI Symposium Berlin 08/12/2015
� EV mode
� Serial mode
� Parallel mode
Multimode Transmission
T.Gassmann, GKN
14th CTI Symposium Berlin 08/12/2015
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
Dedicated Hybrid Transmission Systems:Introduction to OGeco
� ogeco is a hybrid powertrain concept that has minimised on-cost,
reduced complexity and better package in comparison to a Hybrid DCT
� Mechanical efficiency is improved over Hybrid DCT with a more efficient dry
clutch (vs. wet clutch) and two-shaft main transmission layout
� Split personality gear shifting, gives DCT comfort for city driving and best-in-
class shifting for track driving
� Reduced shift time and maximum shift emotion for sport driving
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
2-speed EV
6-speed ICE
OGeco Powerflows
1
54
23
6
Diff
Clutch
ICE
e1 e2
eMotor
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
OGeco Powerflows
1
54
23
6
Diff
Clutch
ICE
e1 e2
eMotor
� Ready to select gears
� P3 Configuration
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
OGeco Powerflows
1
54
23
6
Diff
Clutch
ICE
e1 e2
eMotor
� Driving with ICE
in 2nd Gear
� P3 Configuration
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
OGeco Powerflows
1
54
23
6
Diff
Clutch
e1 e2
eMotor
ICE
� Driving with ICE
in 2nd Gear
� eMotor ready
for electric
drive, eBoost or
Torque Infill
� P3 Configuration
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
OGeco Powerflows
1
54
23
6
Diff
Clutch
e1 e2
eMotor
ICE
� ICE used to charge
battery or crank
engine
� P2 Configuration
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
OGeco vs Dedicated Hybrid Transmission Systems
AVL 8-modeRenault Nissan ZE
EolabGKN Multimode OGeco
Efficiency � 2-open wet clutches
� Dependency between
ICE and EM gears
� 2-speed EV
� 2-shaft design
� No clutch
� 2-speed EV
� Wet clutch open
during driving
� Multiple shafts
� Dry clutch
� Gear ratios independent
� 2-speed EV mode direct
to output
Simplicity / Cost
� Complexity
comparable to AT
� Electric dog
actuation
� No clutches
� Single speed
� multi-plate clutch
� 2EMs
• Complexity comparable
to AMT
Packaging � Comparable to AT � Comparable to MT � Short axial length • Comparable to DCT
Driveability � Difficult to manage
many modes in
intuitive manner?
� Not all shifts are
powershifts
� Single ratio gives
compromise on
acceleration
� Stepped gear ratios,
widely acceptable
� Sporty Feel
Functions � 5-Parallel Hybrid gears
� 2 EV gears
� eCVT mode
� Idle charging
� 3-Parallel hybrid
gears
� 2 EV gears
� No ICE limp home
� EV mode
� Serial mode
� Parallel mode
• 6-Parallel hybrid gears
• 2-speed EV mode
• P2 and P3 selectable
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
OGeco vs Benchmark Modular (add-on) System
Current DCT Hybrid OGeco
Package Worse than today DCT Comparable to today DCT system
Weight [1] On vehicle system weight in the
range of 180-190 kg
On vehicle system weight in the range
of 140-150 kg
Shifting smoothness
DCT system guarantees power shift
manoeuvre at every vehicle speed
Comparable with DCT system up to
medium performance manoeuvre
Sporty shifting
DCT system can have sporty feeling,
but cannot perform as AMT
State of the art of shifting performance
and sporty feeling
Clutch thermal
The wet clutch has a very high
thermal robustness
The EM can reduce the thermal load on
AMT dry clutch
System efficiency [2]
Main issue is hydraulic circuit cooling
of wet double clutch
AMT has 4% of fuel economy
advantage compared to DCT
[1]: Electric motor included/ Battery and Inverter not included
[2]: Average value on different driving cycles/ vehicle applicationsSame ratio and mechanical efficiency considered for both solution
Copyright 2016 VOCIS Limited. Strictly Private & Confidential. All rights reserved
Summary
� Now, more than ever, there are a multitude of competing hybrid
powertrain architectures with electric machines integrated into the
transmission
� The dedicated hybrid transmission concepts presented here,
including OGeco, follow this approach
� Modular systems are valid solutions, but are compromised
� The transmission’s role in hybrid vehicles will become ever more
integrated, allowing for optimisation of multiple sources of traction
� And also facilitate better packaging, cost, weight ….
� Mechanical complexity of the transmission can be reduced with
electrification without compromising performance and comfort
� Market drivers show that now is the right time to consider next
generation powertrains for 2020 and beyond
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