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Smart Phasing –
Needs based concepts for camshaft phasing systems
Kevin Poole
Schaeffler Symposium 2014 Kevin Poole 1
Functional requirements for VCT Systems
En
gin
e lo
ad
Flexibility for engine start
Time
Ca
ms
ha
ft a
ng
le
Engine
speed
Camshaft timing accuracy
Time
Da
Shifting velocity
Time
Da
Dt
Engine speed
Schaeffler Symposium 2014 Kevin Poole 2
…and the changing oil pressure landscape
En
gin
e lo
ad
Flexibility for engine start
Time
Ca
ms
ha
ft a
ng
le
Engine
speed
Camshaft timing accuracy
Time
Da
Shifting velocity
Time
Da
Dt
Engine speed
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0 1000 2000 3000 4000 5000 6000 7000
Oil
pre
ss
ure
in
ba
r
Engine speed in rpm
2004
Engine type: I4
Schaeffler Symposium 2014 Kevin Poole 3
…and the changing oil pressure landscape
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0 1000 2000 3000 4000 5000 6000 7000
Oil
pre
ss
ure
in
ba
r
Engine speed in rpm
2004
2008
Engine type: I4
Schaeffler Symposium 2014 Kevin Poole 4
…and the changing oil pressure landscape
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0 1000 2000 3000 4000 5000 6000 7000
Oil
pre
ss
ure
in
ba
r
Engine speed in rpm
2004
2008
2012
Engine type: I4
Schaeffler Symposium 2014 Kevin Poole 5
Comparison of system capabilities S
hif
tin
g v
elo
cit
y
Oil
co
ns
um
pti
on
High Low High Low
HCP with cartridge OCV
HCP with central OCV
Pressure accumulator
ECP
OPPORTUNITY!
-10
-5
0
5
10
-100 -50 0 50 100
Dyn
am
ic C
am
sh
aft
to
rqu
e in
Nm
Camshaft angle in °Cam
Schaeffler Symposium 2014 Kevin Poole 6
Fundamentals of cam phasing dynamic cam torque
Stator Rotor
-10
-5
0
5
10
-100 -50 0 50 100
Dyn
am
ic C
am
sh
aft
to
rqu
e in
Nm
Camshaft angle in °Cam
Schaeffler Symposium 2014 Kevin Poole 7
Fundamentals of cam phasing dynamic cam torque
Stator Rotor
Schaeffler Symposium 2014 Kevin Poole 8
Fundamentals of cam phasing dynamic cam torque C
am
sh
aft
ph
aser
an
gle
in
°C
am
Retard
Advance
Schaeffler Symposium 2014 Kevin Poole 9
Fundamentals of cam phasing oil flow
FPull = const.
Bowl
pEnviroment
Vacuum
"B"
A
B
Stator Rotor
"B"
Schaeffler Symposium 2014 Kevin Poole 10
Solving the vacuum issue oil reservoir
Camshaft phaser
P T
A B
A B
Oil control valve
A
B
Oil volume
Schaeffler Symposium 2014 Kevin Poole 11
Solving the vacuum issue oil reservoir
Time
a (Standard)
Q (Standard)
Ave
rag
e o
il f
low
Q o
il p
um
p
Cam
sh
aft
an
gle
a
Q (Smart phaser)
DQ
a (Smart phaser)
Da
Schaeffler Symposium 2014 Kevin Poole 12
Design - camshaft phaser
Standard
Oil res
volume
Reed check valve
Smart Phaser
Stator
Rotor
Sprocket
Schaeffler Symposium 2014 Kevin Poole 13
Design - oil control valve
B A
T
P
Standard
B A
P
Oil reservoir supply port
V
Smart Phaser
Schaeffler Symposium 2014 Kevin Poole 14
Oil flow – phasing to base position
A - A
A
Central solenoid Camshaft phaser
Central valve
Camshaft
T
P
B A
B
Schaeffler Symposium 2014 Kevin Poole 16
Simulation – Standard phaser shift velocity vs oil flow
0
100
200
300
400
500
600
0 2 4 6 8 10
Sh
ifti
ng
ve
loc
ity i
n
°Cr/
s
Average oil flow of oil pump in L/min
0
100
200
300
400
500
600
0 2 4 6 8 10
Sh
ifti
ng
ve
loc
ity i
n
°Cr/
s
Average oil flow of oil pump in L/min
0
100
200
300
400
500
600
0 2 4 6 8 10
Sh
ifti
ng
ve
loc
ity i
n
°Cr/
s
Average oil flow of oil pump in L/min
1,5 bar
2,5 bar
3,5 bar
4,5 bar
0,5 bar ±5 Nm
±20 Nm
Camshaft torque
Oil pressure
Schaeffler Symposium 2014 Kevin Poole 17
Simulation – Smart phaser shift velocity vs oil flow
0
100
200
300
400
500
600
0 2 4 6 8 10
Ve
rste
llg
es
ch
win
dig
ke
it [
°KW
/s]
Mittlerer Ölvolumenstom in L/min
0
100
200
300
400
500
600
0 2 4 6 8 10
Sh
ifti
ng
ve
loc
ity i
n
°Cr/
s
Average oil flow of oil pump in L/min
±5 Nm
0,5 bar 1,5 bar 2,5 bar
3,5 bar
4,5 bar
±20 Nm
Schaeffler Symposium 2014 Kevin Poole 18
Simulation – Smart phaser shift velocity vs oil flow
0
50
100
150
200
250
300
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
Sh
ifti
ng
ve
loc
ity i
n
°Cr/
s
Average oil flow of oil pump in L/min
±5 Nm
±10 Nm
±15 Nm
±20 Nm Standard
Smart phaser
Schaeffler Symposium 2014 Kevin Poole 19
Test results – shift velocity
-300
-200
-100
0
100
200
300
0 1000 2000 3000 4000 5000 6000 7000 8000
Sh
ifti
ng
ve
loc
ity i
n
°Cr/
s
Engine speed in rpm
Oil temperature: 90°C
to a
dvance
to
reta
rd
1200 rpm Sh
ifti
ng
ve
loc
ity i
n °
Cr/
s
Engine speed in rpm
Standard
Smart phaser
Schaeffler Symposium 2014 Kevin Poole 20
Test results C
am
sh
aft
ph
aser
an
gle
in
°C
am
Retard
Advance
ZOOM
Schaeffler Symposium 2014 Kevin Poole 21
Test results
R
A
Ca
ms
ha
ft p
ha
se
r a
ng
le in
°C
am
Standard
Oil
pre
ss
ure
in
ba
r
Oil pressure in camshaft
Schaeffler Symposium 2014 Kevin Poole 22
Test results
Oil pressure in chamber A
R
A
Oil
pre
ss
ure
in
ba
r C
am
sh
aft
ph
as
er
an
gle
in
°C
am
Standard
Schaeffler Symposium 2014 Kevin Poole 23
Test results
Oil pressure in chamber B
Oil
pre
ss
ure
in
ba
r
R
A
Ca
ms
ha
ft p
ha
se
r a
ng
le in
°C
am
Standard
Schaeffler Symposium 2014 Kevin Poole 24
Test results
Standard
Oil
pre
ss
ure
in
ba
r
R
A
Ca
ms
ha
ft p
ha
se
r a
ng
le in
°C
am
Smart phaser
Schaeffler Symposium 2014 Kevin Poole 25
Test results
+0
.5 °
Ca
m
Vacuum
Oil
pre
ss
ure
in
ba
r
R
A
Ca
ms
ha
ft p
ha
se
r a
ng
le in
°C
am
Standard Smart phaser
Schaeffler Symposium 2014 Kevin Poole 26
Comparison of system capabilities - revisited S
hif
tin
g v
elo
cit
y
Oil
co
ns
um
pti
on
High Low High Low
HCP with cartridge OCV
HCP with central OCV
Pressure accumulator
ECP
Smart phaser
Schaeffler Symposium 2014 Kevin Poole 27
Smart phasing solving the hydraulic camphasing puzzle
significantly reduced
oil consumption
higher shifting velocity
at equal controllability / and significantly reduced
oil consumption
higher shifting velocity
at equal controllability
If something doesn’t yet exist,
I invent it. ” ‟
Enrico Luccherini
1932 -
If something doesn’t yet exist,
invents it! ” ‟
VCT Systems Team
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