ECS / Disclosure or duplication without consent is prohibited
Synchronization methods of automated gearboxes for electric driven
light commercial vehicles (LCV) Dipl.-Ing. Reinhard Buchberger
Development Engineer Drivetrain Engineering Magna Powertrain,
Engineering Center Steyr, Austria www.ecs.steyr.com ECS /
Disclosure or duplication without consent is prohibited2013 LMS
European Vehicle Conference Basis Vehicle & Gearbox Shifting
Sequence & Synchronization Methods Simulation Models Simulation
& Test Results Conclusion Content Author: Buchberger R.2Date:
2013-10-30 ECS / Disclosure or duplication without consent is
prohibited2013 LMS European Vehicle Conference Basis Vehicle
Author: Buchberger R.3Date: 2013-10-30 Light Commercial Vehicle
(LCV) Gross Vehicle Weight 3000 kg Vehicle Performance Maximum
velocity: 120 km/h (0.5% grade) Maximum gradeability: >40% 5%
gradeability at 80 km/h / >20% gradeability at 15 km/h Design by
MAGNA STEYR 0%10%20%30%40%50%0 20 40 60 80 100 120Gradeability [%]
Velocity [km/h] Gear 1 - Peak PowerGear 2 - Peak PowerGear 1 -
Continuous PowerGear 2 - Continuous PowerPeak gradeability Cont.
gradeability ECS / Disclosure or duplication without consent is
prohibited2013 LMS European Vehicle Conference ECS eDrive Module
eAMT300-2e Description Front axle module for electric driven
commercial vehicle Features/Specifications Power and torque @360V
105kW peak / 45kW continuous 280 Nm peak / 150 Nm continuous
2-speed automated gearbox Gear ratio: i1= 14.0 /i2=8.6optimized for
drivability, comfort & efficiency Electro-mechanic actuation 12
V DC Actuator Threaded spindle for longitudinal fork movement 100%
recuperation on Steyr Delivery Cycle (SDC09) PTO for A/C compressor
Parking pawl EV-CU for extended energy Management Author:
Buchberger R.4Date: 2013-10-30 ECS / Disclosure or duplication
without consent is prohibited2013 LMS European Vehicle Conference
Advantages of a 2-speed eDrive Module Author: Buchberger R.5Date:
2013-10-30 Up to 7% less energy demand Lower life cycle costs
caused by smaller battery Extended continuous gradeability Lower
noise emissions Higher acceleration 0-50 km/h PTO for load point
shifting, also useable on vehicle standstill Lower motor costs
based on torque reduction Economy drive + More complex design
Higher module costs - ECS / Disclosure or duplication without
consent is prohibited2013 LMS European Vehicle Conference Basis
Vehicle & Gearbox Shifting Sequence & Synchronization
Methods Simulation Models Simulation & Test Results Conclusion
Content Author: Buchberger R.6Date: 2013-10-30 ECS / Disclosure or
duplication without consent is prohibited2013 LMS European Vehicle
Conference Shifting Sequence Author: Buchberger R.7Date: 2013-10-30
Not a strict step-by-step sequence Partial overlappings in
dependency of shifting method overall shifting time reduction Start
of shifting sequence Torque release Disengagement Synchronization
Engagement Torque build up End of shifting sequence Acceleration or
deceleration of traction motor (high inertia to synchronize)
Different methods possible Mechanically only Mechanically with
active support of traction motor Traction motor only ECS /
Disclosure or duplication without consent is prohibited2013 LMS
European Vehicle Conference Synchronization Methods Author:
Buchberger R.8Date: 2013-10-30 Mechanical Synchronizer alone
Mechanical Synchronizer Triple cone system Traction motor acts as a
passive part Actuating force 1000 N due to active use of system
tensioning (rotary inertia in combination with low shifting fork
stiffness and self-retention) Low synchronization torque 72 Nm
acting at the gearbox intermediate shaft(33 / 20 Nm at the motor
shaft depending on gear) Mechanical synchronizer ECS / Disclosure
or duplication without consent is prohibited2013 LMS European
Vehicle Conference Synchronization Methods Author: Buchberger
R.9Date: 2013-10-30 Mechanical Synchronizer + Tractionmotor Same
mechanical synchronizer as before Tractionmotor supports mechanical
synchronizer as an active part End of the synchronization sequence
is mechanically only Difference in rotating speed has to be exactly
zero Electrical synchronization can start before mechanical
synchronization starts overall shifting time reduction
0501001502002503000 5000 10000Torque [Nm] Speed [rpm] Maximum
electrical synchronization torque ECS / Disclosure or duplication
without consent is prohibited2013 LMS European Vehicle Conference
Synchronization Methods Author: Buchberger R.10Date: 2013-10-30
Tractionmotor alone Mechanical synchronizer without synchronizer
cones shifting teeth with spline shape Low difference in rotating
speed at coupling pointnecessary ( 10 rpm) 60 teeth Robust dog
clutch with less teeth 14 teeth High difference in rotating speed
at coupling pointpossible ( 250 rpm) Rather high circumferential
backlash Complete new design necessary With optimized package same
axial installation space required as mechanical synchronizer Robust
dog clutch with 14 teeth ECS / Disclosure or duplication without
consent is prohibited2013 LMS European Vehicle Conference Basis
Vehicle & Gearbox Shifting Sequence & Synchronization
Methods Simulation Models Simulation & Test Results Conclusion
Content Author: Buchberger R.11Date: 2013-10-30 ECS / Disclosure or
duplication without consent is prohibited2013 LMS European Vehicle
Conference Development Process Author: Buchberger R.12Date:
2013-10-30 Co-Simulation Software code generation Verification of
simulation results ECS development process Gearbox prototype
Drivetrain test bench Simulation model(Control path) Simulink
(Controller) ECU (Hardware + Software from ECS) ECS / Disclosure or
duplication without consent is prohibited2013 LMS European Vehicle
Conference Simulation Model Author: Buchberger R.13Date: 2013-10-30
Traction Motor Simulink Interface Electro-Mechanic Actuator Vehicle
Model 2-speed Gearbox ECS / Disclosure or duplication without
consent is prohibited2013 LMS European Vehicle Conference 3D
Visualization Author: Buchberger R.14Date: 2013-10-30 Better/easier
understanding of complex systems during development process
Plausibility check Exact 3D geometry necessary (CAD import)
Shifting sequence with robust dog clutch Detail view of shifting
sequence ECS / Disclosure or duplication without consent is
prohibited2013 LMS European Vehicle Conference Basis Vehicle &
Gearbox Shifting Sequence & Synchronization Methods Simulation
Models Simulation & Test Results Conclusion Content Author:
Buchberger R.15Date: 2013-10-30 ECS / Disclosure or duplication
without consent is prohibited2013 LMS European Vehicle Conference
Results Mech. synchronization vs. mech. + electr. synchronization
Author: Buchberger R.16Date: 2013-10-30 Variant without active
support oftraction motor is very slow Active support of traction
motor starts before friction cones get in contact (as soon as
gearbox is at neutral) Clutch engagement Varies with relative
angular position of clutch parts at simulation start. e.g. tooth
hits gap (green curve) or tooth hits tooth (red curve) Green =
mechanical synchronizer only Red = mechanical synchronizer with
active support of traction motor Traction motor torque (air gap)
Effective synchronizer torque Start of shifting sequence Torque
[Nm] Position [m] Speed [rpm] ECS / Disclosure or duplication
without consent is prohibited2013 LMS European Vehicle Conference
Results Electrical Synchronization Author: Buchberger R.17Date:
2013-10-30 Variant with 14 teeth is faster than 60 teeth variant
Higher difference in rotating speed at coupling point Earlier
torque build up Red = spline shaped shifting teeth (60 teeth) Green
= dog clutch (14 teeth) 14 teeth clutch Shifting fork acts as a
spring and pushes the collar into its counterpart. The spring gets
pre-loaded when the teeth's front faces get in contact. Rotational
speed difference at coupling point. Start of shifting sequence
Torque [Nm] Position [m] Speed [rpm] ECS / Disclosure or
duplication without consent is prohibited2013 LMS European Vehicle
Conference -1-0,500,511,522,533,50 50 100 150 200 250 300 350 400
450 500Longitudinal acceleration [m/s]Time [ms]14 teeth clutch60
teeth clutch-400%-200%0%200%400%600%800%1000%0 50 100 150 200 250
300 350 400 450 500Longitudinal Jerk [m/s]Time [ms]14 teeth
clutch60 teeth clutch100% = max. longitudinal jerk for 60 teeth
clutchResults Electrical Synchronization Author: Buchberger
R.18Date: 2013-10-30 Influence at vehicle dynamics Higher vehicle
acceleration respectively longitudinal jerk for vehicle with 14
teeth dog clutch This might cause passenger comfort impacts! Start
of shifting sequence Longitudinal jerk of vehicle: 10 x higher for
14 teeth dog clutch
ECS / Disclosure or duplication without consent is
prohibited2013 LMS European Vehicle Conference
01002003004005006007008009000 10 20 30 40 50 60 70 80 90 100Time
[ms] Velocity before shifting maneuver [kph] Total shifting time
(Upshift (gear 1 --> gear 2), flat road, max. torque before and
after shifting) MechanicalElectrical + mechanicalElectrical 60
teethElectrical 14 teeth Solid line = overall shifting time Dashed
line = synchronization Results Upshift Author: Buchberger R.19Date:
2013-10-30 Synchronization time dominates advantage for combined
synchronization (highest total synchronization torque)
Disengagement and engagement time dominate advantage for electrical
only synchronization methods Min. and max. shifting time ECS /
Disclosure or duplication without consent is prohibited2013 LMS
European Vehicle Conference Results Downshift Author: Buchberger
R.20Date: 2013-10-30 010020030040050060070080090010000 10 20 30 40
50 60 70Time [ms] Velocity before shifting maneuver [kph] Total
shifting time (Downshift (gear 2 --> gear 1), flat road, max.
torque before and after shifting) MechanicalElectrical +
mechanicalElectrical 60 teethElectrical 14 teeth Solid line =
overall shifting time Dashed line = synchronization time ECS /
Disclosure or duplication without consent is prohibited2013 LMS
European Vehicle Conference Results Dog clutch with or without high
back angle Author: Buchberger R.21Date: 2013-10-30 High back angle
leads to shorter overall shifting times with the disadvantage of a
higher circumferential backlash in engaged position Higher
circumferential backlash might cause NVH problems Reason for
decrease in shifting time Earlier torque build up tooth is pulled
into gap 3 back angle9.5 back angle Reference: Spline shaped
shifting teeth(60 teeth) Circumferential backlash3.85.20.6 Shifting
time decrease0 ms20 40 ms- ECS / Disclosure or duplication without
consent is prohibited2013 LMS European Vehicle Conference Test
bench results 0501001502002503003504004505000 10 20 30 40 50 60 70
80 90 100Time [ms] Velocity [km/h] Test #3:200 Nm* 50 km/h Test
#1:130 Nm* 50 km/h Test #2:130 Nm* 30 km/h Min. and max. shifting
time, depending on start situation Good correlation between
simulation and testing. *) Torque limitation for traction motor
during shifting process Simulation with max. 280 Nm of active
synchronization torque of traction motor.Date: 2013-10-30Author:
Buchberger R.22 ECS / Disclosure or duplication without consent is
prohibited2013 LMS European Vehicle Conference Basis Vehicle &
Gearbox Shifting Sequence & Synchronization Methods Simulation
Models Simulation & Test Results Conclusion Content Author:
Buchberger R.23Date: 2013-10-30 ECS / Disclosure or duplication
without consent is prohibited2013 LMS European Vehicle Conference
Conclusion Author: Buchberger R.24Date: 2013-10-30
No.Synchronization methodProContra 1Mechanical synchronizer
onlyEasy to control Very slow Complex mechanics 2 Mechanical
synchronizer with active support of traction motor FastComplex
mechanics 3 Electrical synchronization with spline shaped shifting
teeth(60 teeth) FastMore difficult to control4 Electrical
synchronization with robust dog clutch (14 teeth) Fastest method
Simple mechanics Easier to control Possibility of NVH and passenger
comfort impacts Higher component loads Method no. 2 was selected
for the MPT ECS eDrive module, since the mechanical synchronizer is
a carryover part, it provides best flexibility and this method
already includes method 1 and 3. One prototype three different
synchronization methods for testing ECS / Disclosure or duplication
without consent is prohibited www.ecs.steyr.com Thank you for your
kind attention
