the transmission’s role in hybrid vehicles · of wet double clutch amt has 4% of fuel economy ......

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


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


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


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


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)


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


Complexity: Trend of Increased Electrification

� Legislation limits and

acceptance of hybrid

technologies are driving

higher electrification of

vehicles, in ever

increasing volumes


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


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


� EV mode

� Serial mode

� Parallel mode

Multimode Transmission

T.Gassmann, GKN



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


2-speed EV

6-speed ICE

OGeco Powerflows

1

54

23

6

Diff

Clutch

ICE

e1 e2

eMotor


OGeco Powerflows

1

54

23

6

Diff

Clutch

ICE

e1 e2

eMotor

� Ready to select gears

� P3 Configuration


OGeco Powerflows

1

54

23

6

Diff

Clutch

ICE

e1 e2

eMotor

� Driving with ICE

in 2nd Gear



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



OGeco Powerflows

1

54

23

6

Diff

Clutch

e1 e2

eMotor

ICE

� ICE used to charge

battery or crank

engine



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


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


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


Thank you for listening

For more information:[email protected] | www.vocis.co.uk | +44 (0)1926 650 308

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the transmission’s role in hybrid vehicles · of wet double clutch amt has 4% of fuel economy ......

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