FLEXIBILITY WITHOUT COMPROMISE ELECTRIC CAM PHASING

2018 Schaeffler SymposiumAndrew Mlinaric – Flexibility Without Compromise: Electric Cam Phasing

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FLEXIBILITY WITHOUT COMPROMISE –ELECTRIC CAM PHASING

ANDREW MLINARIC


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Hydraulic Variable Cam Phasing Systems

Challenges:

Large volume of oil required

High‐oil‐pressure requirements

Parasitic losses

Low‐temperature operation

Trend to Lower Oil Pressures in the ICE

Zero oil pressure at stand stillZero oil pressure at stand still

Engine Oil Pressure (bar)

Engine Speed (rpm)

No oil pressure atstand still and cranking

Oil pressure reduction to optimize fuel economy

Hydraulic cam phasing relies on oil pressure for function


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Operational area with hydraulic cam phasing

Enhanced operational area with electric cam phasing

Operating Conditions

Engine Speed (rpm)

Temperature (°C)


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E‐Motor

Coupling

Gearbox

132 tooth

driven by E‐Motor

connected to sprocket

132 tooth

connected to camshaft

134 tooth

Compact design

Clearance free

Light weight

Brushless E‐Motor

High ratio 1:70

Electric Cam Phasing



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Challenges

Transient Operation

Engine Speed

Engine Start

Time

Engine Shutdown

Engine Start

Engine Speed

Actual Angle

Target Angle

Engine Speed

Time

First combustion


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Engine Start – Comfort

Time in s

Engine Speed in

rpm

Exhaust lift

BDC

Shift to late IVC comfort start

Intake lift

BDCTDC

Exhaust lift

BDC

Shift to early IVC quick start

Intake lift

BDCTDC

Time in s

Engine Speed in

rpm

1stcomb.

2ndcomb.

3rdcomb.

Late IV

CEarly IV

C

Engine Start – Comfort

Time in s

Engine Speed in

rpm

Exhaust lift

BDC

Shift to late IVC comfort start

Intake lift

BDCTDC

Exhaust lift

BDC

Shift to early IVC quick start

Intake lift

BDCTDC

Time in s

Engine Speed in

rpm

1stcomb.

2ndcomb.

3rdcomb.

Late IV

CEarly IV

C


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Engine Start – Cold Start Emissions Early IVC

Late IV

C

Early EVC Late EVC

Test results realized in Nissan JSAE Paper on

benefits of Schaeffler ECP for HC reduction

% Reduction of HC after 15s Current VQ vs. New VR Engine

Source: JSAE 20165353

Hydraulic Cam Phasing


-16.7%Fixed cam position at engine start

Optimized cam position at engine start

% Change in Hydrocarbon Emissions

Engine Start – Cold Start Emissions

Early IVC

Late IV

C

Early EVC Late EVC











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Engine Start – Cold Start Emissions Early IVC

Late IV

C

Early EVC Late EVC










Challenges

Transient OperationEngine Start

Time

Engine Shutdown

Engine Speed


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0

20

40

60

80

100

120

140

Re

lativ

e C

am

Po

sitio

n (

°Cra

nk)

0 100 200 300 400 500 600Time (ms)

0

20

40

60

80

100

120

140

Re

lativ

e C

am

Po

sitio

n (

°Cra

nk)

0 100 200 300 400 500 600Time (ms)

0

20

40

60

80

100

120

140

Re

lativ

e C

am

Po

sitio

n (

°Cra

nk)

0 100 200 300 400 500 600Time (ms)

Transient Shifting – Shifting Event Comparison

Target AngleElectric Cam PhasingHydraulic Cam Phasing

0

20

40

60

80

100

120

140

Re

lativ

e C

am

Po

sitio

n (

°Cra

nk)

0 100 200 300 400 500 600Time (ms)



Infinite range of authority

Smooth shifting eliminates NVH associated with hydraulic systems

0

5

10

15

100 120 140 160 180

Fast reaction

Fast and controlled shifting (>500°Crank/s)


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0

20

40

60

80

100

120

140

Re

lativ

e C

am

Po

sitio

n (

°Cra

nk)

0 100 200 300 400 500 600Time (ms)





0

5

10

15

100 120 140 160 180

Fast reaction


0

20

40

60

80

100

120

140

Re

lativ

e C

am

Po

sitio

n (

°Cra

nk)

0 100 200 300 400 500 600Time (ms)





0

5

10

15

100 120 140 160 180

Fast reaction



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0

20

40

60

80

100

120

140

Re

lativ

e C

am

Po

sitio

n (

°Cra

nk)

0 100 200 300 400 500 600Time (ms)





0

5

10

15

100 120 140 160 180

Fast reaction


Challenges


Time

Engine Shutdown

Engine Speed


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-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

7

Vib

ratio

n A

mp

litud

e (

g)

84 86 88 90 92Time (s)

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

7

Vib

ratio

n A

mp

litud

e (

g)

84 86 88 90 92Time (s)

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

7

Vib

ratio

n A

mp

litud

e (

g)

84 86 88 90 92Time (s)

Engine Shutdown Comfort

Exhaust lift

BDC

Intake lift

BDCTDC

Hydraulic Cam PhasingElectric Cam Phasing

Engine Vibration During Shutdown

Engine vibration during engine shutdown

Engine vibration during shutdown

eliminated

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

7

Vib

ratio

n A

mp

litud

e (

g)

84 86 88 90 92Time (s)

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

7

Vib

ratio

n A

mp

litud

e (

g)

84 86 88 90 92Time (s)

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

7

Vib

ratio

n A

mp

litud

e (

g)

84 86 88 90 92Time (s)

Engine Shutdown Comfort

Exhaust lift

BDC

Intake lift

BDCTDC

Hydraulic Cam PhasingElectric Cam Phasing

Engine Vibration During Shutdown

Engine vibration during engine shutdown

Engine vibration during shutdown

eliminated


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Challenges


Time

Engine Shutdown

Engine Speed

SYSTEMTOPOLOGY


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System Topology

ECP Controller

CAN bus

Camshaft/crankshaft position

Phase current

Hall signalGearbox

E‐Motor

Crankshaft sensor

Camshaft sensorCamshaft

Crankshaft

Engine CPU

Shifting angledemand mapping

System Topology

ECP Controller

Phase current

Hall signalGearbox

E‐Motor

Camshaft

Crankshaft

Temperature sensor signal

Hall sensor signal 3



GND

VCC

CAN bus


Phase connector

Signal connector


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Schaeffler Smart E‐Motor

ECP Controller


Phase current

Hall signalGearbox

E‐Motor

Crankshaft sensor


Crankshaft

Engine CPU

CAN bus


Gearbox

SmartE‐Motor

Camshaft

Crankshaft

Camshaft sensor

Crankshaft sensor

Engine CPU


ECP Controller


Phase current

Hall signalGearbox

E‐Motor

Crankshaft sensor


Crankshaft

Engine CPU

CAN bus


Gearbox

SmartE‐Motor

Camshaft

Crankshaft

Camshaft sensor

Crankshaft sensor

Engine CPU


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Combination of electric motor and controller

Contains Schaeffler ECP control software and high current motor drivers

Reduces cost and complexity of system

Allows further integration of ECP controls on engine ECM

CAN bus


Gearbox

SmartE‐Motor

Camshaft

Crankshaft

Camshaft sensor

Crankshaft sensor

Engine CPU

► Oil pressure independent operation

► Flexible start position

► Comfort engine shutdown

► Direct replacement for hydraulic VCT systems

Summary


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Documents

FLEXIBILITY WITHOUT COMPROMISE ELECTRIC CAM PHASING