full edrives design process - romax technology · large design loops should be avoided by using a...
TRANSCRIPT
Electro-mechanical
Interactions
In the Design of Integrated EV
drivetrains
Dr. Melanie Michon
October 2016
Slide 2CONFIDENTIAL
© Copyright 2016
Agenda
• Requirements for an electro-mechanical design process
o Electro-mechanical interactions add complexity to the process
• Setting out a defined design process and establishing design parallels
o For gears and electrical machine
• Electro-mechanical system interactions
o What interactions can and should be captured at each stage in the design
process
o What methods do we use to capture these
• A suggested toolchain
Slide 3CONFIDENTIAL
© Copyright 2016
Questions..
How do you make sure the product is
FIT FOR PURPOSE
How do you make sure the product meets its
PEFORMANCE AND DESIGN TARGETS?
How do you make sure the product
AVOIDS FAILURE
How do you make sure you meet your
PRODUCT DESIGN CYCLE TARGET
Requirements for your
DESIGN & SIMULATION PROCESS
Project Set-up
PRODUCT DESIGN SPECIFICATION
System optimisation for
ELECTRO-MECHANICAL DESIGN
Slide 4CONFIDENTIAL
© Copyright 2016
Design process is driven by performance targets
Efficiency, energy economy
Driveline NVH, driveability
Durability, duty cycle
Packaging, lay-out, gear stages, physical interfaces
Thermal performance
Mass, cost
Target driven design trade-off: holistic assessment of all targets for
electrical, mechanical AND system interactions
Limited design data is available
Simulation speed is important to assess many concept designs
Simulation accuracy should be sufficient to make concept down-selection
Large design loops should be avoided by using a defined hierarchy in the design process
The analysis (CAE) process determines how these targets can all best be met and
what simulation speed and accuracy to use at different stages of the design process
Slide 5CONFIDENTIAL
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Current simulation toolchain
Simulation of Gearbox
• e.g. Concept + RomaxDesigner
• Implements ‘multi-fidelity’ modelling
• Assessment of all performance targets
• “mechanical engineering”
Simulation of Electrical Machine
• e.g. RMxprt + Maxwell
• Implies ‘multi-fidelity’ modelling
• Assessment of all performance targets
• “electrical engineering”
However, what about gearbox-motor interactions ??
Slide 6CONFIDENTIAL
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Requirements for the EV Design Process
• Simulate and eliminate (identify and avoid) “failure modes” as early as
possible
• Use multi-fidelity analyses for maximum insight with optimum
simulation speed at each stage of the process and to manage data flow
between different departments
• Consider all performance targets and trade-off performance using a
holistic design approach
• Consider electro-mechanical interactions within the drivetrain from
the start
Slide 7CONFIDENTIAL
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DESIGN PROCESS
For Gears and Electrical Machine
Slide 8CONFIDENTIAL
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x1000 Concept Design Options
x10 Concept Design Options
x Design Options
Final Design
Design flow within an EV Design ProcessDown-selection, from many to one. Then optimise
Simulation toolchain
Capture any electro-mechanical
interactions
Sound engineering decision
making tools
Requires the use of multi-fidelity
models
Part Level Definition
• Gear microgeometry, Bearing confirmed
• Stator, Rotor geometry, winding layout
• Detailed housing
System Level Definition
• System Architecture
• Number of gear stages
• Power/Energy ratings
Component Level Definition
• Topology selection
• Ratio split, macrogeometry
• Sizing of electrical machine parts
Slide 9CONFIDENTIAL
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x1000 Concept Design Options
x10 Concept Design Options
x Design Options
Final Design
Main Design Stages in a Concept Design Process
Detailed Design
Vehicle Concept
Layout Design
Concept Design
Tolerances & Sign off
Slide 10CONFIDENTIAL
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Design process for Gearbox
Vehicle
Concept
Topology Sizing - 1 Sizing - 2
Concept DesignLay-out
Bearings
“Ratios”
Concept
HousingDetailed
Housing
Detailed Design Tolerances &
Sign-off
“CAD”
Slide 11CONFIDENTIAL
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Target Vehicle
Concept
Gearbox Layout Gearbox
Concept Design
Detailed Design Tolerances
& Sign-offConcept
Housing
Detailed
HousingTopology Sizing 1 Sizing 2 Concept Bearings
Efficiency
Packaging
Durability
Driveability
Thermal
Noise
Weight
Cost
Design Process for GearboxesAnalysis methods are well-defined
Increasing model fidelity
Increasing input data requirement
Decreasing simulation speed
Slide 12CONFIDENTIAL
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Design process for Electrical Machine
Vehicle
Concept
Topology Sizing - 1 Sizing - 2Materials
Concept DesignLay-out
Winding
“Rating”
2D/3D EM FEA &
Thermal
Detailed Design Tolerances &
Sign-off
Final specification
Slide 13CONFIDENTIAL
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Target Vehicle
Concept
Electrical Machine Layout Electrical Machine
Concept Design
Detailed
Design
Tolerances &
Sign-off
Topology Sizing 1 Sizing 2 Concept Material
Efficiency
Packaging
Durability
Driveability
Thermal
Noise
Weight
Cost
Design Process for Electrical MachinesAnalysis methods are well-defined
Increasing model fidelity
Increasing input data requirement
Decreasing simulation speed
Slide 14CONFIDENTIAL
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The design methods are well established for gearboxes
and motors separately. But what are the electro-
mechanical influences that need to be considered?
Discussion
Slide 15CONFIDENTIAL
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VEHICLE CONCEPT
Slide 16CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 1: Vehicle Concept
Target Vehicle Concept
Efficiency Vehicle drive cycle simulation
Packaging
Durability
Driveability Acceleration and driveability simulation
Thermal
Noise
Weight
Cost Cost for gearbox versus cost for electrical machine
Interaction Trade-off between overall gear design/ratio and machine
torque/power rating, including driving behaviour, hence
vehicle acceleration, driveability and overall efficiency
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Efficiency-driven architecture selectionConcept down-selection trade-offs to be made
• Complex, multi-speed gearbox - electrical machine operating range is limited and
can easily be designed to operate at efficiency ‘hot spot’
• Simple, single-speed gearbox – electrical machine efficiency requires optimisation
over wide operating range
• High overall gear ratio – small, high speed machine
• Low overall gear ratio – large, low speed machine
Driving behaviour and drive cycle selection affects fuel/energy economy, and
design trade-offs
Slide 18CONFIDENTIAL
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Toyota Prius (HEV) case study
Assess many drive cycles
• Urban
• Extra-urban
• Highway
Close to real world driving
Sensitivity studies to assist concept down selection
Concept down selection case study
Slide 19CONFIDENTIAL
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Final drive + planetary ratio
• The values of the final drive and planetary gear ratios
were varied for different drive cycles
• New European Driving Cycle
o Fuel consumption close to optimum
• Artemis Urban: low speed, starting and stopping
o Higher ratios are better
• Highway Fuel Economy Test: high speeds, low
accelerations
o Lower ratios are better
• Combination of eight drive cycles:
o Existing ratios are a good compromise
Final drive ratioP
lan
eta
ry g
ear
rati
o
2 5
2
3
3 4
4
1
Toyota
Prius
Slide 20CONFIDENTIAL
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LAY-OUT
Topology Sizing Basic Concept
Slide 21CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 2: eDriveline Lay-out (Topology)
Target eDriveline Layout (Topology)
Efficiency Qualitative efficiency match between electrical machine and gear
topology (single speed versus multi-speed)
Packaging Space for gearbox versus space for electrical machine
Durability
Driveability
Thermal Does gearbox space claim affect machine thermal capacity
Noise
Weight Mass for gearbox versus mass for electrical machine (qualitative)
Cost Cost for gearbox versus cost for electrical (qualitative)
Interaction Space claim for gearbox versus space claim for electrical
machine
Slide 22CONFIDENTIAL
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Qualitative assessment of topologies
Topology 1 Topology 2 Topology 3 Topology 4
Gear Efficiency ++ ++ + 0
Electrical machine
Efficiency++ - + 0
Packaging ++ + + 0
Electrical machine
thermal performance++ + + 0
eDriveline Weight ++ ++ + +
eDriveline Cost - + ++ +
Slide 23CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 3: eDriveline Layout (Sizing-1) - PACKAGING
Target eDriveline Layout (Sizing-1)
Efficiency Airgap stress method: quickly assess if electrical machine
efficiency dictates available space for gear
Packaging Initial space claim using basic sizing for gear and electrical
machine
Durability Is gear durability affected by machine size requirements
Driveability
Thermal Qualitative: can thermal performance gearbox affect machine
cooling requirement?
Noise
Weight Mass for gearbox versus mass for motor
Cost Cost for gearbox versus cost for motor
Interaction Gearbox/machine sizing within space envelope, affecting
thermal and durability requirements
75 mm
L
Ds
Slide 24CONFIDENTIAL
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Space Claim and lay-out of eDriveline
Initial design assessment of
Gear Centre Distance
required to achieve
durability targets (contact)
L
Ds
Combined with electrical
machine sizing based on
initial thermal assessment
(shear stress)
All within target packaging constraints
Slide 25CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 3: eDriveline Layout (Sizing-1) - DYNAMICS
Target eDriveline Layout (Sizing-1)
Efficiency
Packaging
Durability
Driveability 1st driveline torsional mode based on machine and gear
inertia, reference mount stiffness, response to e.g. shock load
Thermal
Noise Lowest powertrain bending mode provides initial mount
characteristics
Weight
Cost
Interaction Initial dynamic interaction between motor and gearbox
75 mm
L
Ds
Slide 26CONFIDENTIAL
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Driveability and 1st Torsional Mode
Actual profile of average torque
Torsional model (e.g. Matlab) Torsional mode shape from 6 dof model
in RomaxDesigner
Simulation set up and
target parameters
(oscillation and duration of oscillation)
Slide 27CONFIDENTIAL
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Low Frequency Powertrain bending modes and mounts
• These modes fundamentally about mount stiffness, not stiffness of housing/shafts
• Romax has verified that the same results come from
3D Romax model and 1st principles, single mass at
C of G on springs
Mode fn
Corresponding rotor speed
Motor excitation Unbalance
1 13.0 Hz 195 rpm
2 20.0 Hz 1200 rpm
3 31.6 Hz 474 rpm
Slide 28CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 3: eDriveline Layout (Sizing-2) – GEAR RATIO SELECTION/EFFICIENCY
Target eDriveline Layout (Sizing-2)
Efficiency Analytical system efficiency calculation: Selection of gear ratios
affects both gear and electrical machine efficiency
Packaging Space envelope dictates limits in gear ratio/machine torque
Durability Is gear durability affected by tooth number selection,
Qualitative assessment: machine manufacturability may restrict
slot number selection
Driveability
Thermal Lumped parameter model gives initial thermal estimate
Noise
Weight
Cost
Interaction Gear ratio selection affects system efficiency and durability.
Space envelope puts further constraint on optimisation
Slide 29CONFIDENTIAL
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Gear ratio optimisation for all design targets
Overall ratio
Seco
nd
sta
ge r
ati
o
PackagingRatio limits
Smaller, lighter electrical machine
Higher gear ratio
Remaining design space
System efficiency
System durability assessment
NVH motor + gearbox
Slide 30CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 3: eDriveline Layout (Sizing-2) – GEAR RATIO SELECTION/NOISE
Target eDriveline Layout (Sizing-2)
Efficiency Analytical system efficiency: quick assessment if gear/machine
efficiency is affected by selection of tooth/slot/pole numbers
Packaging
Durability Is gear durability affected by tooth number selection,
Qualitative assessment: machine manufacturability may restrict
slot number selection
Driveability
Thermal
Noise Order plot of electrical and mechanical excitations
Weight
Cost
Interaction Order analysis of system excitations drives selection of gear
tooth numbers and machine pole/slot combination
Slide 31CONFIDENTIAL
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Order plot analysis
• Order analysis including both gearbox AND motor excitation orders
• Analytical calculation of excitation frequencies with minimum required input data
• Concept design recommendations can be made (change tooth numbers, number of poles/slots, topology)
No
significant
overlap
Significant
overlap
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E-DRIVELINE CONCEPT
Full concept design
Slide 33CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 4: eDriveline Concept – HIGH SPEED BEARING DESIGN
Target eDriveline Concept
Efficiency RxD incl. e-machine mechanical model: High speed shaft bearing
pre-load affects efficiency
Packaging
Durability RxD incl. e-machine mechanical model: High speed shaft bearing
pre-load affects durability
Driveability
Thermal
Noise RxD: Gear forces -> bearing stiffness -> lateral modes of rotor
shaft
Weight
Cost
Interaction Lateral modes of the high speed shaft are affected by gear
forces, coupling and the rotor design. Bearing pre-load can
avoid unwanted resonances
Slide 34CONFIDENTIAL
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Gear loads, bearing pre-loads, shaft modes and efficiency
Critical speeds of rotor shaft are
dependent on bearing stiffness
Pre-load increases bearing
stiffness but also increases drag;
What is the trade-off?
Low bearing stiffness can lead to resonant frequency
being within the operating range irrespective of the shaft stiffness
Complex interaction with the gear load,
depending on the axial constraints of the bearings etc.
How to select bearing constraints, pre-load, helix angle etc.,
given their impact on shaft critical speed and efficiency
Slide 35CONFIDENTIAL
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Effect of Bearing Stiffness on Motor Resonance
0.1% 10% 30% 100%
Resonance of
1st Mode
(RPM, no
pre-load)
12 227 35 531 42 531 50 656
Test Data
Romax Simulation Critical Speed map
Slide 36CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 4: eDriveline Concept - NOISE
Target eDriveline Concept
Efficiency
Packaging
Durability
Driveability
Thermal
Noise Analytical assessment of initial system response to electrical and
mechanical excitations by the sound power through the bearings
Weight
Cost
Interaction Initial system response to electrical and mechanical
excitations
Slide 37CONFIDENTIAL
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Initial measure for NVH performance of concept design
Identify potential NVH issues early – Right First Time design
How to assess system dynamic response at the
concept stage (no housing!)
Bearing 1
Bearing j
Bearing n
Bearing 2
Sound pressure at
a given location
Gearbox (SOURCE) Acoustic power transmitted through bearings
Powertrain definition, no housing definition
Representative model of generic housing is used
Slide 38CONFIDENTIAL
© Copyright 2016
Gearbox-Motor Interactions through the Design ProcessStep 4: eDriveline Concept – TORQUE RIPPLE
Target eDriveline Concept
Efficiency
Packaging
Durability
Driveability Dynamic Fusion/Simulink/Orchestra: Driver can ‘feel’ torque ripple
driving uphill (high T, low speed)
Thermal
Noise RxD: Torque ripple can excite 1st torsional vehicle mode
Weight
Cost
Interaction Electrical machine torque ripple may affect vehicle driveability
Slide 39CONFIDENTIAL
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Investigate driveability through dynamic model of
electro-mechanical system
Intelligent creation of multi-body dynamics model:
Appropriate degrees of freedom for each dynamic problem
Optimal computation time
Integrates with Adams, Modelica or Simulink
This enables driveability investigations and control system design, e.g.
“anti-jerk” control
response to high torque ripple at low speed/high torque
Slide 40CONFIDENTIAL
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E-DRIVELINE DETAILED DESIGN
Housing design and detailed electromagnetic analysis
Slide 41CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 4: eDriveline Detail – Unbalanced Magnetic Pull
Target eDriveline Detail
Efficiency Analytical/FEA & RxD to assess if airgap length is affected by
static UMP and may affect efficiency
Packaging Bearing selection and position may be affected by UMP
Durability Analytical/FEA & RxD to assess if high speed shaft bearing
selection is affected by static UMP in electrical machine
Driveability
Thermal
Noise
Weight
Cost
Interaction Static Unbalanced Magnetic Pull (UMP) in electrical machine
interacts with gear deflections and may affect bearing
selection and/or airgap length
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Static Unbalanced Magnetic Pull interacts with
mechanical system and may affect bearing selection
Gearbox housingMotor stator
Motor rotor
Air
gap
Static system analysis:
Deflection of the shaft/bearing/ housing system due to
mechanical loads (e.g. gear loads)
Rotor eccentricity leads to Unbalanced Magnetic Pull
Bearing selection may be affected by UMP
Airgap length may be affected by UMP
Slide 43CONFIDENTIAL
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System and multi-physics interactions
for the rotor shaft assembly
Durability Efficiency Noise/Dynamics
Gear loads affect bearing life Gear loads also affects bearing
stiffness and motor lateral dynamics
Bearings require pre-load to avoid
no-load dynamics problems
Bearings pre-load affects bearing
drag and mechanical efficiency
Bearings pre-load affects bearing
durability
Gear loads deflects the rotor
UMP causes the deflection to
increase
UMP also affects the bearing loads
and hence durability
UMP also affects the bearing loads
and hence mechanical drag
UMP also affects the bearing loads
and hence stiffness and eigenvalues
Gearbox related
Motor related
UMP also affects gear misalignment
and hence micro-geometry & stress
UMP also affects gear misalignment
and hence micro-geometry &
efficiency
UMP also affects gear misalignment
and hence micro-geometry & TE
UMP acts as a negative stiffness and
changes eigenvectors
All causes of rotor displacement give
rise to need for air gap which affects
electrical efficiency
Slide 44CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 5: eDriveline Detail – NOISE
Target eDriveline Detail
Efficiency
Packaging
Durability
Driveability
Thermal
Noise RxD and electro-magnetic FEA to calculate the system response
to electrical and mechanical excitations
Weight
Cost
Interaction System response (including housing) to mechanical AND
electrical excitations
Slide 45CONFIDENTIAL
© Copyright 2016
Calculation of the excitation from gears (transmission error) and motor (torque ripple, imbalance
and radial force shapes)
Harmonic analysis to determine electrical machine
excitation force shapes
8th harmonic 16th harmonic 24th harmonic
Harmonic
analysis
Complex stator radial force shape
Slide 46CONFIDENTIAL
© Copyright 2016
H=48, 8472 rpmH=48, 936 rpm
1st stage, 8208rpm2nd stage, 6516rpm
System response to gear AND e-machine excitations
Slide 47CONFIDENTIAL
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Torque ripple
Initial NVH analysis is already possible with a concept
housing design to guide the design
• Concept housing design, e.g. space claim functionality
• Unit excitations for TE, analytical calculation of dominant force shapes
• Determine where peaks occur in response
Radial force shapes Transmission Error
Slide 48CONFIDENTIAL
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Identify potential design actions from the simulation:
1st Gear Mesh Transmission Error
• Gearbox casing wall excited by vibration
through left hand bearing
• Potential Design Actions:
o Remove left hand bearing
o Introduce ribs on offending panel
to reduce vibration
Slide 49CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 5: eDriveline Detail – DYNAMIC SYSTEM RESPONSE INCLUDING CONTROL
Target eDriveline Detail
Efficiency
Packaging
Durability
Driveability Advanced dynamic simulation to assess system dynamics, e.g.
shock load response
Thermal
Noise Advanced dynamic simulation to assess effect of control
strategies on noise
Weight
Cost
Interaction Dynamic system response due to electro-mechanical
interactions and control system influences
Slide 50CONFIDENTIAL
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Electro-mechanical system analysis and control design
Dynamic Fusion:
Discretised model with
correct number of DOF
Mechanical system Electrical & Control systemControlled Electro-mechanical system
Combined system description
Including electrical and mechanical
representations
• DQ transformation of machine quantities
• Include control of electrical machine
Slide 51CONFIDENTIAL
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Control of electrical machine affects electro-mechanical
interactions
• D-Q transformation is used for system analysis and
control design
• PI controller is implemented for torque control
PI
controllerid
iq
Te* Torque-
current
conversion
id*
iq*
vd
vq
SPM including field weakening Effect of control parameter design on torsional
response of combined electro-mechanical system
Electro-mechanical interactions introduce additional
LF torsional modes
Control parameter selection affects torsional modes
Slide 52CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 5: eDriveline Detail – ELECTRO-MAGNETIC/MECHANICAL MACHINE DESIGN
Target eDriveline Detail
Efficiency Any effects on airgap can affect efficiency, stresses on
lamination pack can affect iron losses
Packaging
Durability
Driveability Shock load response can affect peak torque and may lead to
demagnetisation
Thermal Any longer transients can affect thermal performance
Noise Dynamic UMP can cause additional excitations in electrical
machine, also axially
Weight
Cost
Interaction Interactions of electro-magnetic and mechanical design in
electrical machine, e.g. dynamic UMP
Slide 53CONFIDENTIAL
© Copyright 2016
Areas of ongoing research
• Unbalanced Magnetic Pull in electrical machines:• M. Michon, R. Holehouse, K. Atallah, G. Johnstone, ‘Effects of rotor eccentricity in large synchronous
machines’, IEEE Transactions on Magnetics 2014
• M. Michon, R. Holehouse, K. Atallah, J. Wang, ‘Unbalanced magnetic pull in permanent magnet machines’,
IET International Conference on Power Electronics, Machines and Drives 2014
• M. Michon, K. Atallah, G. Johnstone, ‘Effects of unbalanced magnetic pull in large permanent magnet
machines’, IEEE Energy Conversion Congress and Exhibition 2014
• ‘Smart’ co-simulation of electro-magnetic and mechanical interactions – derive
multi-fidelity methods to incorporate into concept design process• Knowledge Transfer Partnership with the University of Sheffield
• System dynamics including electro-mechanical and control interactions:• B. Wang, M. Michon, R. Holehouse, K. Atallah, ‘Dynamic behaviour of a multi-MW wind turbine’, IEEE
Energy Conversion Congress and Exhibition 2015
Slide 54CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 5: eDriveline Detail – MECHANICAL DESIGN FOR TORQUE
Target eDriveline Detail
Efficiency
Packaging RxD: Torque -> bolting pattern/mounts -> deflections
Durability RxD/Analytical: additional loads on bolted joints between e-
machine and gearbox need to be accounted for
Driveability
Thermal
Noise
Weight
Cost
Interaction Electro-magnetic torque affects bolted joints between e-
machine and gearbox
Slide 55CONFIDENTIAL
© Copyright 2016
• Need to take care of how the structure responds to the torque
action/reaction with regard to the gearbox and motor
o Integrity of bolted joint
o Gear misalignment
o Air gap (with UMP etc.)
o Spline rating/misalignment
o Bearing loads along motor axis
• 2, 3 or 4 bearings
Torque -> bolting pattern/mounts -> deflections
Reactions from
mounts
Torque from wheels
Split plane,
shear of bolted joint
Slide 56CONFIDENTIAL
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Gearbox-Motor Interactions through the Design ProcessStep 5: eDriveline Detail – SYSTEM THERMAL PERFORMANCE
Target eDriveline Detail
Efficiency Advanced efficiency calculations to assess how temperature
affects gearbox losses
FEA for electrical machine efficiency
Packaging
Durability Assessment of temperature hotspots (e.g. windings)
Driveability
Thermal Lumped parameter model of complete system, gear meshes
and machine losses as source
Noise
Weight
Cost
Interaction Assessment of system thermal performance including
mechanical and electrical parts
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Thermal modelling of eDrivelineHeat flow
• System-level thermal models used to evaluate heat
flow through the drivetrain
• Evaluation of drivetrain thermal performance and
efficiency
o Total energy loss over each drive-cycle
o Fluid and component temperature limits
EM heat
exchanger
GB bulk heat
exchanger Sump
EM thermal
model
EM energy
to/from
coolant
GB bulk
thermal model
GB losses
Conduction between
EM and GB
EM
losses
Cooling Cooling
GB loss heat
exchanger
GB energy
to/from
coolant
Splitter
Environment
Slide 58CONFIDENTIAL
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Thermal/Efficiency/Tribology modelling of eDrivelineUnderstanding inter-relationship between the different physics
Drive Cycle
Oil properties
LTCA
Heat generated
Temperature dependent efficiency models
Slide 59CONFIDENTIAL
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Target Vehicle
Concept
eDriveline Layout eDriveline
Concept Design
eDriveline
Detailed Design
eDriveline
Tolerances &
Sign-offTopology Sizing 1 Sizing 2
Efficiency
Packaging
Durability
Driveability
Thermal
Noise
Weight
Cost
Gearbox-Motor Interactions through the Design ProcessSummary – changes in the methods applied
Increasing model fidelity
Increasing input data requirement
Decreasing simulation speed
Slide 60CONFIDENTIAL
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Summary
• A multi-physics, multi-fidelity approach to simulation is
necessary for robust design of an eDrives system
o Many different functional targets with different physics
o Multi-fidelity to provide different needs within the design process
• Products for simulating gearboxes and motors have been
developed along this approach, but nothing exists for motor-
gearbox interactions
