new features for more efficient manual transmissions with

New Features for more efficient Manual Transmissions with additional Customer Benefit14th International VDI Congress, Friedrichshafen, 2014-06-24Wulf Leitermann, Matthias Brosi, Rafael Prellezo

Agenda

1. Global Manual Transmission Market

2. Future Market Requirements for Manual Transmissions

3. New Features for more efficient Manual Transmissions

− Increased overall Spread and Number of Gears

− Reduction of parasitic Losses

− Automated Clutch

4. Next Generation Inline Manual Transmission Family

5. Summary

2

New Features for more efficient Manual Transmissions with additional Customer Benefit

2014-06-24© GETRAG, 14th International VDI Congress, Drivetrain for Vehicles, Friedrichshafen June 2014, Wulf Leitermann, Matthias Brosi, Rafael Prellezo

Global manual transmission volumes will increase. Inline manual transmission market is shrinking and moving from passenger cars to light commercial vehicles.

2014-06-24© GETRAG, 14th International VDI Congress, Drivetrain for Vehicles, Friedrichshafen June 2014, Wulf Leitermann, Matthias Brosi, Rafael Prellezo4

RWD MT Light Commercial Vehicle Production < 3,5 t; > 250 Nm RWD MT Passenger Car Production < 3,5 t; > 250 Nm

Light Vehicle Production < 3,5 t (Passenger Cars and Light Commercial Vehicles)


Further improvements of manual transmissions is requested. Additional functions under consideration, due to customer acceptance and on-costs.


New design features requested:

� Overall spread > 7,5

� Oil management

� Significantly reduced parasitic losses in all components

� Gears

� Bearings

� Seals

All features have to consider best cost efficiency

Additional design features optional:

� 7-speed gear set

� Automated clutch

Functional aspects considered as standard:

� Shiftability according specific OEM DNA

� Fulfillment of NVH targets


3. New Features formore efficient Manual Transmissions

Increased overall spread reduces fuel consumption, but effects transmission and powertrain attributes.


� Increased overall spread is the major contributor to reduce fuel consumption and emissions� down speeding in higher gears� 3 … 4 %, depending on engine and

vehicle application

� Improvement for WLTC slightly higher than for NEDC

But high overall spread effects drivability and design attributes:


90,0

95,0

100,0

WLTC

Phi = 6,3

Phi = 7,5

Feature Challenge Approach

Increased gear steps Driving maneuvers @ low speed 7-speed gear set

Down-speeding Tractive effort decrease @ high speed Engine characteristic

Increased center distance Transmission weight Adjusted design philosophy

rela

tive fu

el

co

nsu

mp

tio

n [%

]

Reduction of splash loss directly correlates to complexity of chosen technical solution.


Passive Oil Management:

Oil shield separates gear set from oil sump

� Controlled oil flow

� Reduced oil volume

� Significantly reduced splash losses and oil temperature

Active Oil Management:

Dry sump lubrication by scavenge pump and injection lubrication

� Further reduced splash losses

� but, higher

• complexity

• weight

• costs

0

25

50

75

100

1000 1/min 3500 1/min

w/o oil shield

with oil shield

0

25

50

75

100

NEDC WLTC

passive

active

Energy loss reductionpassive vs. active oil management

Splash losses

without vs. with oil shield


rela

tive s

pla

sh

losse

s [%

]

-54

%

-40

%

rela

tive e

ne

rgy

loss r

ed

uctio

n [%

]

Further improvement on component level are possible, but to some extent cost-benefit outcome questionable.



Component Measure

Gear set� Low loss gear design� Coating

Bearings� Smaller bearings, due to

reduced axial and radial forces

Synchronizer� Reduces drag torque� Reduced number of

cones

Oil � Reduction of viscosity

Seals� Optimized sealing lip

design and reduced preload

Manual transmission is a very mature system� all efficiency improvement measures to

be reflected against - Cost- Customer benefit- End customer acceptance

Automated clutch system could improve MT functionality and fuel efficiency


Automated clutch system features and advantages:

� Sailing possible for MTs� CO2 reduction in WLTC ca. 7%

� in real life even higher

� Stop-and-go assist

� Launch control

� Drivetrain protection

� NVH improvement by clutch micro slip

Base for MT hybrids!

Add-on automated clutch system components:

� Clutch actuator + position sensor

� Clutch pedal + position sensor

� Control unit (pot. integrated in ECU)


Automated wet clutch concept based on GETRAG DCT technology will offer further advantages.


Fully integrated automated wet clutch concept based on GETRAG modules:

� Wet clutch using DCT components

� Pump actuator carry-over from DCT

� Oil suction and cooling based on DCT design features

� Clutch control using DCT software modules

Advantages of integrated wet clutch system:

� Better controllability of wet clutch system

� Higher robustness against high energy events

� Significantly reduced inertia and weight

� Usage of mass production components and controls


4. Next Generation Inline MT Family

Volatile market and technical requirements needs to be addressed in the next generation inline MT concept


Volatile inline MT volumes

� Shrinking volumes for premium passenger cars

� Increasing global volumes for light commercial vehicles (LCV)

?


Segmented inline MT market

� Premium passenger cars

� Sport cars

� LCV

Variety of technical requirements

� 250 … 800 Nm

� Different mission profiles(sport car vs. LCV)

� Number of gears(6 vs. 7-speed)

� Overall ratio spread

� Fuel efficiency

Common requirements for all applications

� Best shiftability

� NVH optimized

� Flexibility for different applications and innovations

� Low product costs

� Best reliability

New flexible inline MT architecture supports huge variety of customer requirements.


Major design features:

� One center distance for all variants

� Overall spread > 7,5 feasible

� Reduced axial and radial loads

� Low loss gear design

� Carry over components MT/DCT

� Best shiftabilty and NVH

� Optimized design costs

Protected options:

� 7-speed gear set module

� Active oil management

� Mid and high torque gear sets

� Fuel efficiency measures

New design and manufacturing approach:

� Mid and high torque derivatives by adjusted gear width

� Axial flexibility of bearings position and shift system provided

� Common base of MT and DCT without negative effects on:

• Weight

• Complexity of MT and DCT


5. Summary

New and optimized functionality for manual transmission is feasible and base for GETRAGs new flexible MT architecture


� Major contributors for fuel efficiency improvement are

• Increased overall spread for down-speeding � potentially 7-speed gear set needed

• Automated clutch to enable sailing

� Improvements on component level (oil management, low viscosity oil, low loss gear design …) are feasible

� Due to cost sensitivity of manual transmissions each optimization has to be cross-checked regarding cost-benefit outcome and could be different for specific applications or markets

� Technically meaningful features like 7-speed or automated clutch has to be checked against end customer expectation and acceptance

� GETRAG could offer a new flexible manual transmission architecture, which reflects optimized functionality. New functions are optional.

5. Summary

new features for more efficient manual transmissions with

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