(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)(19) World Intellectual Property Organization
International Bureau

11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111(10) International Publication Number(43) International Publication Date

22 September 2011 (22.09.2011)

PCT(51) International Patent Classification:
F02B 25100 (2006.01)
F02B 41106 (2006.01)
F02B 33122 (2006.01)(21) International Application Number:
PCT/US20ll/028281(22) International Filing Date:
14 March 2011 (14.03.2011)

WO 2011/115870 A1BADAIN, Nicholas; 37 Rosslyn Road, Shoreham-BySea, West Sussex BN43 6WL (GB). GILBERT, Ian; 67
Beach Green, Shoreham-By-Sea, West Sussex BN43 5YE(GB).
(74) Agents: FILDES, Christoher, J. et al.; Fildes & Outland, P.C., 20916 Mack Avenue, Suite 2, Grosse Pointe
Woods, MI 48236 (US).

(71) Applicant (for all designated States except US): SCUDERI GROUP, LLC [US/US]; 1111 Elm Street, Suite 33,
West Springfield, MA 01089 (US).

(8 l) Designated States (unless otherwise indicated, for every
kind of national protection available): AE, AG, AL, AM,
AO, AT, AU, AZ, BA, BB, BG, BH, BR, BW, BY, BZ,
CA, CH, CL, CN, CO, CR, CU, CZ, DE, DK, DM, DO,
DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT,
HN, HR, HU, ID, IL, IN, IS, JP, KE, KG, KM, KN, KP,
KR, KZ, LA, LC, LK, LR, LS, LT, LU, LY, MA, MD,
ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI,
NO, NZ, OM, PE, PG, PH, PL, PT, RO, RS, RU, SC, SD,
SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, TR,
TT, TZ, VA, UG, US, UZ, VC, VN, ZA, ZM, ZW.

(72) Inventors: MELDOLESI, Riccardo; 55 New Road,
Shoreham-By-Sea, West Sussex BN43 6RB (GB).

(84) Designated States (unless otherwise indicated, for every
kind of regional protection available): ARIPO (BW, GH,(25) Filing Language:

English(26) Publication Language:

English(30) Priority Data:
61/313,831
61/363,825
61/365,343

15 March 2010 (15.03.2010)13 July2010 (13.07.2010)18 July2010 (18.07.2010)

us
us
us

---- ------------------------------------------------------------------------------------------- FIG. 1[Continued on next page](54) Title: SPLIT-CYCLE AIR-HYBRID ENGINE WITH COMPRESSOR DEACTIVATION------------(57) Abstract: A split-cycle air-hybrid engine includes a rotatable crankshaft.
A compression piston is slidably received within a compression cylinder andoperatively connected to the crankshaft. An intake valve selectively controls
air flow into the compression cylinder. An expansion piston is slidably received within an expansion cylinder and operatively connected to the
crankshaft. A crossover passage interconnects the compression and expansion
cylinders. The crossover passage includes a crossover compression (XovrC)
valve and a crossover expansion (XovrE) valve therein. An air reservoir is operatively connected to the crossover passage. In an Air Expander (AE) mode
and an Air Expander and Firing (AEF) mode of the engine, the XovrC valve is
kept closed during an entire rotation of the crankshaft, and the intake valve is
kept open for at least 240 CA degrees of the same rotation of the crankshaft.

W 0 2011/11587 0 A1 11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
GM, KE, LR, LS, MW, MZ, NA, SD, SL, SZ, TZ, UG,
ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, MD, RU, TJ,
TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK,
EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU,
LV, MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK,

SM, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ,
GW, ML, MR, NE, SN, TD, TG).
Published:-with international search report (Art. 21(3))

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PCT/US2011/028281

SPLIT-CYCLE AIR-HYBRID ENGINE WITH COMPRESSOR DEACTIVATIONTECHNICAL FIELD

This invention relates to split-cycle engines and,more particularly,S

to such an engine incorporating an air-hybrid system.

BACKGROUND OF THE INVENTION

For
10engine"aspurposes

used

in

of

the

clarity,present

theterm "conventional

applicationreferstoaninternal combustion engine wherein all four strokes of thewell-known

Otto

compression,

expansion

cycle(i.e.,

the(or power)

intake(orinlet),and exhaust strokes)

arecontained in each piston/cylinder combination of the engine.
15

Each stroke requires one half revolution of the crankshaft(180 degrees crank angle(CA)), and two full revolutions of

the crankshaft (720 degrees CA) are required to complete theentire Otto cycle in each cylinder of a conventional engine.
Also,
20

for

purposesofclarity,thefollowing

definition is offered for the term "split-cycle engine" as
may be applied to engines disclosed in the prior art and as
referred to in the present application.
A

split-cycle

engineasreferredtohereincomprises:25

a crankshaft rotatable about a crankshaft axis;acompression
crankshaft

compression
cylinder
such

that

pistonslidablyandoperatively

thecompression

received withinconnected

pistontoathe

reciprocatesthrough an intake stroke and a compression stroke during a30

single rotation of the crankshaft;

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2
(

an

expansion(power)pistonslidablyreceived

within an expansion cylinder and operatively connected tothe crankshaft such that the expansion piston reciprocatesthrough an. expansion stroke and an exhaust stroke during a5single rotation of the crankshaft; andacrossoverpassage(port)

compression and expansion cylinders,
including

at

least

a

crossoverinterconnecting

thethe crossover passage

expansion(XovrE)

valve

disposed therein, but more preferably including a crossover
10compression(XovrC)valve and a crossover expansion(XovrE)valve-defining a pressure chamber therebetween.
United States Patent No.
8,2003 to Scuderi and United States Patent No.

granted October 11,
15

6, 543,225 granted April

2005 to Branyon et al.,are incorporated herein by reference,
discussion
addition,ofsplit-cycle

and6, 952,923

both of whichcontain an extensive

similar-type

engines.

In

these patents disclose details of prior versionsof an engine of which the present disclosure details.further
developments.
20

Split-cycle
cycle

enginewithanair-hybrid
airengines

reservoir

combineand variousasplit-

controls.

This combination enables a split-cycle air-hybrid engine to
store

energyreservoir.
25

in

the

form

of

compressed

air

in

the

air

The compressed air in the air reservoir is later

used in the expansion cylinder to power the crankshaft.
A

split-cycle

air~hybrid

engineasreferredtoherein comprises:
a crankshaft rotatable about a crankshaft axis;
a30

compression
crankshaft

compression
cylinder
such

that

pistonslidablyandoperatively

thecompression

received withinconnected

pistontoathe

reciprocatesthrough an intake stroke and a compression stroke during asingle rotation of the crankshaft;

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3

anexpansion(power)pistonslidablyreceived

within an expansion cylinder and operatively connected tothe crankshaft such that the expansion piston reciprocatesthrough an expansion stroke and an exhaust stroke during a5single rotation of the crankshaft;acrossoverpassage(port)

compression and expansion cylinders,
including

at

least

a

crossoverinterconnecting

thethe crossover passage

expansion(XovrE)

valve

disposed therein, but more preferably including a crossover
10compression (XovrC)

valve and a crossover expansion(XovrE)valve defining a pressure chamber therebetween; andancrossoverairreservoir

passageandoperatively

selectively

connected

operable

to

to

the
store

compressed air from the compression cylinder and to deliver
15

compressed air to the expansion cylinder.
United States Patent No.
8,202008 to Scuderi et al.,7, 353,78 6 granted April

which is incorporated herein byreference,contains an extensive discussion of split-cycle

air-hybrid

andsimilar-type

engines.

In

addition,

thispatent discloses details of prior hybrid systems of which
the present disclosure details further developments.
A split-cycle air-hybrid engine can benormal operating or firing
the25

Enginemodes.

Firing(EF)

In the EF mode,

(NF)

mode)

mode
and

run in a(also commonly called
four

basic

air-hybrid

the engine functions as a non-air

hybrid split-cycle engine, operating without the use of its
air reservoir.

In the EF mode,connecting

crossovertheapassagetank valve operatively
to

the

air

reservoir

remains closed to isolate the air reservoir from the basic
30

split-cycle engine.
The

split-cycle

air-hybrid

engineoperates

the use of its air reservoir in four hybrid modes.
hybrid modes are:

SUBSTITUTE SHEET (RULE26)

with

The fourwo 2011/115870

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4

1)

Air

Expandercompressed

(AE)

air

mode,

energy

which

from

includes

the

air

using

reservoir

without combustion;
2)
5

Air Compressor(AC)compressedenergyairmode,which includes storing

into

the

air

reservoir

without combustion;
3)

Air Expander and Firing (AEF) mode, which includes
using compressed air energy from the air reservoir
with combustion; and10

Firing4)

andstoring

Charging

compressed

(FC)
air

mode,

which

includesenergy

into

the

air

AE,

AC,

reservoir with combustion.
However,further

AEF and FC,
15

optimization of these modes,. EF,

is desirable to enhance efficiency and reduce

emissions.

SUMMARY OF THE INVENTION

The present invention provides a split-cycle air20

hybrid engine in which the use of the Air Expander (AE) modeand the Air Expander and Firing (AEF) mode are optimized forpotentiallyanyvehicle

in

any

drive

cycle

particularly,

anexemplaryfor

improved

efficiency.
More25

embodimentofasplit-cycle air-hybrid engine in accordance with the present
invention includes a crankshaft rotatable about a crankshaft
axis.

A compression piston is slidably received within acompression
crankshaft
30

cylinder
such

that

and

operatively

thecompression

connected
pistontothereciprocatesthrough an intake stroke and a compression stroke during asinglerotationofthecrankshaft.

Anintakevalve

selectively controls air flow into tne compression cylinder.
An expansion piston is slidably received within an expansion

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5cylinder and operatively connected to the crankshaft

suchthat the expansion piston reciprocates through an expansion
stroke and an exhaust stroke during a single rotation of the
crankshaft.
5Acrossoverpassageinterconnects

thecompression and expansion cylinders.

The crossover passage

includes(XovrC)acrossovercompression

crossover

expansion(XovrE)

chamber

therebetween.

An

valve
air

valve

and

a

pressuredefining

reservoirisaoperatively

connected to the crossover passage and selectively operable
10

to store compressed air from the compression cylinder and todeliver compressed air to the expansion cylinder.

An airreservoir valve selectively controls air flow into and out

15of the air reservoir.

The engine

Expanderan Air

mode.

(AE)

mode

and

an entire

operable

ExpanderIn the AE and AEF modes,

closed for

is

and

in an Air

Firingthe XovrC valve

rotation of the

(AEF)

is

crankshaft,

kept

and theintake valve is kept open for at least 240 CA degrees of thesame rotation of the crankshaft.
A method
20ofoperatingengine.is also disclosed.

asplit-cycle

air-hybrid

The split-cycle air-hybrid engine

includes a crankshaft rotatable about a crankshaft axis.

A

compression piston is slidably received within a compression
cylinder and operatively connected to the crankshaft

suchthat the compression piston reciprocates through an intake
25

stroke and a compression stroke during a single rotation of
the crankshaft.

An intake valve selectively controls air

flow into the compression cylinder.
slidablyreceived

operatively
30

withinconnected

toanexpansionthecrankshaft

expansion piston

reciprocatesandstrokeanexhaustcrankshaft.

A

An expansion piston isduringcrossoverthroughacylinder
such

that

and
the

an

expansion

strokesinglerotationoftheinterconnects

thepassagecompression and expansion cylinders.

The crossover passage

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6
includesacrossovercompression

crossover

expansion(XovrE)

chamber

therebetween.

An(XovrC)

valve
air

valve

and

a

pressure

detining

reservoirisaoperatively

connected to the· crossover passage and selectively operable
5

to store compressed air from the compression cylinder and todeliver compressed air to the expansion cylinder.

An airreservoir valve selectively controls air flow into and outof theair

Expander10

mode.

reservoir.

(AE)

mode

The engine

and

an

Air

is

operable

Expanderandin an Air

Firing(AEF)

The ·method in accordance with the present invention

includesthefollowing

steps:

keeping

the

XovrC

valve

closed for an entire rotation of the crankshaft; and keeping

15

the intake valve

open for at least

same

the

rotationofcrankshaft,

2 4 0 CA degrees of thewherebythecompression

cylinder is deactivated to reduce pumping work performed by
the compression piston on intake air.
These

and

other

featuresandadvantages

of

the

invention will be more fully understood from the following
detailed description of the invention taken ·together with the20

accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGSIn the drawings:
25

FIG. 1 is a lateral sectional view of an exemplary
split-cycle air-hybrid engine in accordance with the present
invention; andFIG. 2 is a graphical illustration of pumping load(in terms of negative IMEP) versus engine speed in accordance30

with the present invention.

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7
DETAILED DESCRIPTION OF THE INVENTION

The following glossary of acronyms and definitionsof terms used herein is provided for reference.
5

In General
Unless otherwise specified,all valve opening andclosing timings are measured in crank angle degrees after
top dead center of the expansion piston (ATDCe).
Unless10otherwise

specified,

all

valve

durations

are in crank angle degrees (CA).
Air tank (or air storage tank): Storage tank for compressed
air.
ATDCc: After top dead center of the compression piston.
ATDCe: After top dead center of the expansion piston.

15

20

Bar: Unit of pressure, 1 bar = 10 5 N/m 2
BMEP:

Brake

referstotheoutputas

outputshaft),

after

frictionfor.

Brake Mean Effective Pressure

effective

pressure.

deliveredThe

tolossesthe"Brake"crankshaft( FMEP)(BMEP)

term

are

(or

accounted

is the engine's

brake torque output expressed in terms of a mean effective
pressure(MEP)

value.

BMEP is equal

divided by engine

displacement.

parameter

after

taken

Accordingly,
25

mean

the

to the brake torqueThislosses

BMEP=IMEP-friction.

usually also expressed in terms

is

the

performance

due

to

friction.

Friction,in this case isof an MEP value

known asFrictional Mean Effective Pressure (or FMEP).
Compressor:

The

compression

cylinderandits

associatedits

associatedcompression piston of a split-cycle engine.
Expander:30

The

expansion

cylinderandexpansion piston of a split-cycle engine.
FMEP: Frictional Mean Effective Pressure.

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8
Indicated

IMEP:

Mean

Effective

Pressure.

The

term

"Indicatedu refers to the output as delivered to the top of
the piston, before friction losses (FMEP) are accounted for.
Inlet
5(or intake) :Inlet valve.

Also commonly referred toas the intake valve.
Inlet air(or intake air) : Air drawn into the compression

cylinder on an intake (or inlet) stroke.
Inlet valve(or intake valve) : Valve controlling intake ofgas into the compressor cylinder.
10

Pumping work (or pumping loss): For purposes herein, pumping
work (often expressed as negative IMEP) relates to that partof engine power which is expended on the induction of the
fuel

and air charge

into the engine

and the expulsion of

combustion gases.
15

ResidualCompression

deactivation:the

The ratio

compression

intake

Ratio

valve

(a/b)

cylinderclosestoduringcompressionofthe trapped volume in(a)cylinderattheposition

just

when

the

(b)

the

trappedvolumeinthecompression cylinder just as the compression piston reaches20

its top dead center position (i.e., the clearance volume).
RPM: Revolutions Per Minute.
Tankvalve:

Valve

connecting

the

Xovr

passagewith

thecompressed air storage tank.
VVA:
25

Variable

operable

to

valve

alter

actuation.

A

shape

timingtheormechanism
of

a

or

methodvalve's

lift

profile.
Xovr(orXaver)

valve,

passage

or

port:

The

crossovervalves, passages, and/or ports which connect the compression
and30

expansion

cylindersthrough

which

gas

flows

from

compression to expansion cylinder.
XovrC(or XoverC)

valves:Valves at

the compressor end of

the Xovr passage.

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9
XovrC

valve

fully· closed

andIntake

XovrC

valve

fully

closedandIntake

XovrC

valve

fully

closedandIntakeXovrC-clsd-Int-clsd:
valve fully closed.
XovrC-clsd-Int-oEen:
valve fully open.
5

XovrC-clsd-Int-std:

valve having standard timing.
XovrC-open-Int-clsd: XovrC valve fully open and Intake valve
fully closed.
XovrC-std-Int-std:
10

XovrC

valve

havingstandard

timingandIntake valve having standard timing.
Referring to FIG. 1, an exemplary split-cycle airhybrid engine is shown generally by numeral 10.

The split-

cycle air-hybrid engine 10 replaces two adjacent cylinders
of
15

a

conventional

enginewithacombinationofcompression cylinder 12 and one expansion ·cylinder 14.

oneAcylinder head 33 is typically disposed over an open· end of
the expansion and compression cylinders 12, 14 to cover andseal the cylinders.
The
20

four

strokes

of

the

Otto

cycle

are

"split"over the two cylinders 12 and 14 such that the compression
cylinder 12, together with its associated compression piston
20,

25

performtheintakeandcompression

strokes,andtheexpansion

cylinderexpansion

pistonstrokes.

The Otto cycle is therefore completed in these twocylinders

12,

14

14,

30,

once

together

perform

per

the

with

its

expansion

crankshaft

16

associatedandexhaustrevolution(360

degrees CA) about crankshaft axis 17.
During the intake stroke, intake air is drawn into
the30

compression

disposedinthecylinder12cylinderheadthrough33.

anintakeport

Aninwardly

opening

19(opening inwardly into the cylinder and toward the piston)poppet intake valve 18 controls fluid communication between
the intake port 19 and the compression cylinder 12.

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10

Duringthecompression

stroke,piston20

chargeinto the crossover passage

pressurizes

the

air

chargetheand drives(or port)

typically disposed in the cylinder head 33.
5compression
22,

the

air

which isThis means that.

the compression cylinder 12 and compression piston 20 are asourceofhigh-pressure

gas

to

the

crossover passage

22,

which acts as the intake passage for the expansion cylinder
14.

In some embodiments, two or more crossover passages 22

interconnect the compression cylinder 12 and the expansion
10cylinder 14.
The geometric (or volumetric) compression ratio of
the compression cylinder 12 of split-cycle engine 10
forsplit-cycle

enginesingeneral)isreferred to as the "compression ratio"
15

engine.

herein(andcommonlyof the split-cycle

The geometric (or volumetric) compression ratio of

the expansion cylinder 14 of split-cycle engine 10 (and for
split-cycle engines in general)is herein commonly referred

to as the "expansion ratio" of the split-cycle engine.

The

geometric compression ratio of a cylinder is well known in20

the art as the ratio of the enclosed (or trapped) volume inthecylinder(including

reciprocating therein

all

is at

its

position to the enclosed volume25

thecylinder when

(TDC)

position.

definedherein,recesses)when

pistonbottom dead center(BDC)(i.e., clearance volume)

said piston isatSpecificallysplit-cycle

the

a

for

compression

its

ratio

top deadofaincenterengines

ascompression

cylinder is determined when the XovrC valve is closed.

Also

specifically for split-cycle engines as defined herein,

theexpansion ratio of an expansion cylinder is determined when30

the XovrE valve is closed.
Due to very high compression ratios
1,

30

to

1,

cylinder 12,

40

to

1,

or greater)

an outwardly opening

within the(e.g.,

20 tocompression(opening outwardly away

SUBSTITUTE SHEET (RULE 26)

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11

from

the

cylinder)

valve

24

at

controlpoppetthe ·crossover

flow

from

the

crossover passage 22 ..
5(e.g.,

crossover

20 to 1,

passagecompression
Due

30 to 1,compression
inlet

25

is

used

to

cylinder

12

into

the

to very high

40 to 1,

(XovrC)

expansionor greater)

ratioswithin the

expansion cylinder 14, an outwardly opening poppet crossover
expansion (XovrE) valve 26 at the outlet 27 of the crossover
passage 22 controls flow from the crossover passage 22 into
the expansion cylinder 14.
10

The actuation rates and phasingof the XovrC and XovrE valves 24,

26 are timed to maintainpressure

in

a

high

minimumpressure(typically 20 bar or higher at full

load)

duringthecrossoverpassage22

at

all four strokes of the Otto cycle.
At
15

least one fuelinjector 2 8 injects

fuel

into

the pressurized air at the exit end of the crossover passage
22 in correspondence with the XovrE valve 26 opening, which
occurs shortly before expansion piston 30 reaches
deadcenterposition.

The

air/fuel

chargeits

topenterstheexpansion cylinder 14 when expansion piston 30 is close to
20

its

top

descent

deadcenterfrom its

position.

As

piston

top dead center position,

30

beginsits

and while

the

XovrE valve 26 is still open, spark plug 32, which includesaspark plug

tip

39

that

protrudes

intocylinder14,isfired to initiate combustion in the region around the spark
25

plug

tip

39.

Combustion

can

be

initiated

while

the

expansion piston is between 1 and 30 degrees CA past its top
dead center (TDC) position.

More preferably, combustion canbe initiated while the expansion piston is between 5 and 25
degrees CA past its top dead center
30

(TDC)

position.

Most

preferably, combustion can be initiated while the expansion
piston is between 10 and 20 degrees CA past its top deadcenter(TDC)

initiated

position.

throughother

Additionally,
ignition

combustion

devices

SUBSTITUTE SHEET (RULE 26)

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12

such

as

with

glow

plugs,

microwave

ignitiondevicesor

exhaust

gases

are

through compression ignition methods.
Duringtheexhauststroke,pumped out of the expansion'cylinder 14 through exhaust port
5

35 disposed in cylinder head 33.
exhaust valve 34,

An inwardly opening poppet

disposed in the inlet 31 of the exhaust

port 35, controls fluid communication between the expansion
cylinder 14 and the exhaust port 35.
and
10

the

exhaustpassage 22.

port

35

are

The exhaust valve 34

separate

from

the

crossoverThat is, exhaust valve 34 and the exhaust port

35 do not make contact with,or are not disposed in,thecrossover passage 22.
With the split-cycle engine concept, the geometricengine15

parameters

length,(i.e.,

volumetriccompression

12

and

bore,

stroke,connecting

rodcompression

ratio,

etc.)

the

expansion

14cylindersofaregenerally

independent from one another.

For example, the crank throws

36,

cylinder

38

for

the

compression

12

and

expansion

cylinder 14, respectively, may have different radii and may
20

be phased apart from one another such that top dead center(TDC) of the expansion piston 30 occurs prior to TDC of thecompression piston 20.
cycle

engine10

toThis independence enables the split-

potentiallyachievehigherefficiency

levels and greater torques than typical four-stroke engines.
25

The geometric independence of engine parameters inthe split-cycle engine 10 is also one of the main reasons
why pressure can be maintained in the crossover passage 22
as discussed earlier.
reaches

30

its

top

Specifically, the expansion piston 30

deadcenterposition

prior

to

the

compression piston reaching its top dead center position bya discreet phase angle(typically between 10 and 30 crank

angle

phase

degrees) .

This

angle,

togetherwithpropertiming of the XovrC valve 24 and the XovrE valve 26, enables

SUBSTITUTE SHEET (RULE 26)

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13

the

split-cycle

engine10

tomaintainpressurecrossover passage 22 at a high minimum pressure

in

the

(typically

20 bar absolute or higher during full load operation) during
all four strokes of its pressure/volume cycle.
5

That is, thesplit-cycle engine 10 is operable to time the XovrC valve 24
and the XovrE valve 26 such that the XovrC and XovrE valves
are both open for a substantial period of time (or period of
crankshaft

rotation)

during which the expansion piston

30

descends from its TDC position towards its BDC position and10

thecompression piston 20

simultaneously ascends

BDC position towards its TDC position.
time
26(or crankshaft rotation)

are

both

transferred
15

( 1)

a

the

period,from

During the period ofthat the crossover valves 24,

substantially

equal

mass

of

air

is

from the compression cylinder 12 into thecrossover passage 22 andtoexpansion(2)cylinderfrom the crossover passage 22
14.

Accordingly,· during

thisthe pressure in the crossover passage is prevented

dropping(typically
20

open,

from its

20,

below

a

predetermined

minimum

30,

40

bar

duringorabsolutepressure
full

load

operation) .

Moreover,engine cycle(typically 80% of the entire engine cycle orgreater),during a substantial portion of thethe XovrC valve 24 and XovrE valve 26 are bothclosed to maintain the mass of trapped gas in the crossover
passage 22 at a substantially constant level.
25

As a result,the pressure in the crossover passage 22 is maintained at apredetermined minimum pressure during all

fourstrokes ofthe engine's pressure/volume cycle.
For

purposesherein,themethodofhavingtheXovrC 24 and XovrE 26 valves open while the expansion piston
30

30 is descending from TDC and the compression piston 20 isascending toward TDC in order to simultaneously transfer a
substantially

equal

mass

of

gas

into

and

out

of

the

crossover passage 22 is referred to herein as the Push-Pull

SUBSTITUTE SHEET (RULE 26)

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14method of gas transfer.

It

is theenablesthecrossoverthepressureinPush-Pull method that
passage

22

of

the

split-cycle engine 10 to be maintained at typically 20 bar
or higher during all four strokes of the engine's cycle when5

the engine is operating at full load.
As

discussed

disposed in theseparatefromearlier,

exhaust portthecrossovertheexhaustofthecylinderpassage

22.

The

35

valve

34

is

head

33

structuralarrangement of the exhaust valve 34 not being disposed in10

the crossover passage 22, and therefore the exhaust port 35
not sharing any common portion with the crossover passage
22,

is preferred in order to maintain the trapped mass ofgas in the crossover passage 22 during the exhaust stroke.
Accordingly,
15

large cyclic drops

in pressure are prevented

which may force the pressure in the crossover passage below
the predetermined minimum pressure.
XovrE valve 26 opens shortly before the expansion

20

piston 30

reaches

time,pressure

the

its top dead center position.
ratio

of

the

pressure

At thisincrossoverpassage 22 to the pressure in expansion cylinder 14 is high,due to the fact that the minimum pressure in the crossover
passageistypically20

barabsoluteorhigherandthepressure in the expansion cylinder during the exhaust stroke
is typically about one to two bar absolute.
25

when XovrE valve 26 opens, the pressure in crossover passage
22

is substantially higher than the pressure in expansion

cylinder 14
This

high

and/or30

In other words,(typically in the order of 20 to 1 or greater) .
pressurefuelhigh speeds.

chargeratio
tocausesflow

initialflow

theinto expansion cylinder

14

air
at

These high flow speeds can reach the speed ofsound, which is referred to as sonic flow.
isofparticularly

advantageous

because it causes atoThis sonic flow

split-cycle

rapid combustion event,

SUBSTITUTE SHEET (RULE 26)

engine10

which enables

wo 2011/115870

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15

the

split-cycle

pressures

even

engine10

tothoughignitionmaintainishighinitiatedcombustion
while

the

expansion piston 30 is descending from its top dead center
position.
5

The split-cycle air-hybrid engine 10 also includes
an air reservoir(tank)

4 0,

which is operatively connectedto the crossover passage 22 by an air reservoir (tank) valve
42.

Embodiments with two or more crossover passages 22 may

include a tank valve 42 for each crossover passage 22, which
10

connect to a common air reservoir 40, or alternatively eachcrossover passage 22 may operatively connect to separate air
reservoirs 40.
The tank valve 42 is typically disposed in an air
reservoir

15(tank)

port

44,

which

passage 22 to the air tank 40.
divided into aandaextends

reservoircrossover

The air tank port

first air reservoir

second air

from(tank)(tank)

port

44

is

port section 46
section48.

The

first air tank port section 46 connects the air tank valve
42 to the crossover passage 22, and the second air tank port
20

section 48 connects the air tank valve 42 to the air tank
4 0.

The

includesvolumetheofvolume

the
of

first
all

air

tank

additional

port

ports

sectionand46

recesses

which connect the tank valve 42 to the crossover passage 22
when the tank valve 42 is closed.
25

The tank valve 42 may be any suitable valve device
or system.

For example, the tank valve 42 may be an active

valve which is activated by various valve actuation devices(e.g.,

pneumatic,

Additionally,30

hydraulic,the tank valve

cam,electricor

42 may comprise asystem with two or more valvesthelike).

tank valve

actuated with two or moreactuation devices.
Air tank

40

isutilized

to

store

energyintheform of compressed air and to later use that compressed air

SUBSTITUTE SHEET (RULE 26)

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16

to

power

the

crankshaft

16,

as

described

intheaforementioned United States Patent No. 7,353,786 to Scuderi
et al.

This mechanical means for storing potential energy

provides5

numerous

potential

state of the art.

advantages

For instance,

over

the

the split-cycle engine 10

can potentially provide many advantages in fue1
gains

and

NOx

emissionscurrent

reductionatefficiency

relatively

lowmanufacturing and waste disposal costs in relation to othertechnologies
10

on

the

market,such

asdieselengines

andelectric-hybrid systems.
Byclosingofselectively
the

air

tank

controlling

the

valve

thereby42

andopening

and/orcontrolling

communication of the air tank 40 with the crossover passage
22,
15

the split-cycle air-hybrid engine 10 is operable in an

Engine Firing

(EF)

mode,

an Air Expander

(AE)

mode,

an AirCompressor (AC) mode, an Air Expander and Firing (AEF) mode,
and a Firing and Charging (FC) mode.

The EF mode is a non-hybrid mode in which the engine operates as described above

20

without the use of the air tank 40.

The AC and FC modes areenergymode

storagemodes.

The

AC

is

an

air-hybrid

operating mode in which compressed air is stored in the air
tank

25

40

without

combustion

cylinder14(i.e.,

utilizingthekinetic

engineduring10

nooccurringfuelenergybraking.

intheexpenditure),

expansion

such

as

by
the

of

a

vehicleincluding

The

FC

mode

an

is

air-hybrid

operating mode in which excess compressed air not needed for
combustion is stored in the air tank 4 0,such asthan full engine load

vehicle cruisingat constant speed) .
30

mode

has

an

(e.g.,

engine idle,

at

less

The storage of compressed air in the FCenergycost(penalty);

therefore,itisdesirable to have a net gain when the compressed air is usedat alater time.

usage modes.

The AE and AEF modes are stored energy

The AE mode is an air-hybrid operating mode in

SUBSTITUTE SHEET (RULE 26)

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17which compressed air stored in the air tank 40 is used todrive the expansion piston 30 without combustion occurringin the expansion cylinder 14
The
5

AEF

mode

is

an

(i.e.,

air-hybrid

no

fuel

operatingexpenditure) .

mode

in

which

compressed air stored in the air tank 40 is utilized in the
expansion cylinder 14 for combustion.
In the AE and AEF modes,
12

ispreferably deactivatedtothe compression cylinder

minimizeorsubstantiallyreduce pumping work (in terms of negative IMEP) performed by10

thecompression

piston20

onintake

air.

As

will

be

discussed in further detail herein, the most efficient way todeactivate the compression cylinder 12 is to keep the XovrC
valve 24 closed through the entire rotation of the crankshaft
16, and ideally to keep the intake valve 18 open through the15

entire rotation of the crankshaft.
In

engineoutwardly opening,

embodiments

where

the

intakevalve

isthe intake valve may be kept open throughthe entire rotation of crankshaft.

However,

this exemplary

embodiment illustrates the more typical configuration where20

the intake valve 18 is inwardly opening.

Therefore, in order

to avoid compression piston 20 to intake valve 18 contact at
the top of the compression piston's stroke, the intake valve
18 must be closed prior to when the ascending piston 20 makes
contact with the inwardly opening valve 18.
25

Additionally,
trapped air

isintakeclosing

valve

not

it

is

important

to insure

that

the

compressed too muchfrom the

angle

of

compression

piston

in

to

TDC

of

the

order to avoid excessive temperature and pressure build-up.
Generally, this means that the residual compression ratio at30

the point of intake valve 18 closing should be 20 to 1 orless,and more

preferably 10

to

1 or

less.

In

exemplaryengine 10, the residual compression ratio will be about 20 to
1 at an intake valve 18 closing angle(position) of about 60

SUBSTIT:UTE SHEET (RULE 26)

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18

CA degrees before TDC of the compression piston 20.
intakevalve

closing

is

60

CA

degrees

before

When

TDC,

it

is

highly desirable (as discussed in greater detail herein) that
intake valve opening be 60 CA degrees after TDC.
5

Accordingly, in order to deactivate the compression
cylinder 12 without excessive build-up of air temperature andpressure,

it is preferable that the intake valve 18 be kept

open through at least 240 CA degrees of the rotation of the
crankshaft
10

16.

Moreover,

it

is

more

preferable

that

the

intake valve 18 be kept open through at least 270 CA degrees
oftherotation

preferable

that

of
the

the

crankshaft

16,

and

intake

valve

kept

open

be

it

is

most

throughat

least 300 CA degrees of rotation of the crankshaft 16.

15

responseAs

theintaketo

avoiding

asposition

18

compression

contact, air compression
occur

valve

is

closedsolelyinpiston

20

valve

18

to

(and therefore negative work)

piston20

ascends

toward

its

top

dead

(TDC).

In order to maximize efficiency,

will

centera primaryaim is therefore to reopen the intake valve 18 at a timing
20

when the pressure in the compression cylinder 12 is equal tothe pressure in the intake port 19
differential

betweenthe(i.e., when the pressurecompression

intake port 19 is substantially zero).
the25

openingtimingoftheintakecylinder

12

and

the

In an ideal system,
valve

18

would

be

symmetrical with the closing timing of the intake valve 18
about

top

However,indeadcenterpractice,ofthecompression

after

the

intakevalve

piston18

20.

closesduring the compression stroke of the compression piston 20,
the pressure and temperature in the compression cylinder 12.
30

begins to rise.

Some of the heat generated is lost to thecylinder components
crown,

such as the cylinder walls,

and the cylinder head.

Therefore,

the piston

the pressure in

the compression cylinder 12 and intake port 19 is equalized

SUBSTITUTE SHEET (RULE 26)

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19

at a slightly earlier timing(relative to top dead center)on the intake stroke of the compression piston 20 than on
the compression stroke.

In addition,

wave effects in theintake port 19 and the flow characteristics of the intake
5valve 18 (such as the fact that flow is quite restricted at
low valve lifts)

result in the optimum closing and opening

timing of the intake valve 18 deviating slightly from truly
symmetrical about top dead center.
Therefore,
10

it

is

important

to

keep

the

closing

position (timing) and opening position (timing) of valve 18
substantially(i.e.,

within plus

or minus

10 CA degrees)

symmetrical with respect to TDC of piston 20,

in order toreturn as much of the compression work to the crankshaft 16
as possible.
15

For example, if the intake valve 18 is closed

at substantially 25 CA degrees before TDC of the compression
piston 20 · to avoid being hit by thepiston 20,

then

the

valve 18 should open at substantially 25 CA degrees after
TDC of piston 20.

In this way, the compressed air will act

as an air spring and return most of the compression work to20

the crankshaft 16 as the air expands and pushes down on thecompression piston 20 when the piston 20 descends away from
TDC.
Accordingly,

in order to avoid compression piston

20 to valve 18 contact and to reverse as much compression
25

work

as

possible,itopening

positions(timing)ispreferable
of

valve

that

the

closing18

aresymmetrical,

andwithin plus or minus 10 CA degrees, about TDC of compression
piston 20 (e.g.,
before TDC,
30

degrees

if intake valve 18 closes at 25 CA degrees

then it must open at

after

TDC

of

piston20).

25 plus or minus
However,

it

is

10 CA
more

preferable if the closing and opening positions of valve 18
are symmetrical,

within plus or minus 5 CA degrees,

TDC of piston 20,

about

and most preferable if the closing and

SUBSTITUTE SHEET (RULE 26)

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PCT/US2011/028281

20
opening positions of valve 18 are symmetrical,

within plus

or minus 2 CA degrees, about TDC of piston 20.
Also,

in the AE and AEF modes,

the air tank valve

42 is preferably kept open through the entire rotation of the5

crankshaft 16(i.e.,

the air tank valve 42 is kept open atleast during the entire expansion stroke and exhaust· strokeof the expansion piston) .

Compressed air stored in the airtank 40 is released from the air tank 40 into the crossover
passage 22 to provide charge air for the expansion cylinder
10

14.

In the AE mode, compressed air from the air tank 40 isadmitted to the expansion cylinder 14,
anexpansion

stroke.

The

expansion stroke of theairthe exhaust stroke.
the air tank 40
with

fuel

at

expandedon

expansion piston 30,

power to the crankshaft 16.
15

is

at the beginning of
the

same

transmitting

The air is then discharged on

In the AEF mode,

compressed air fromis admitted to the expansion cylinder 14

thebeginningofanexpansion

stroke.

The

air/fuel mixture ,is ignited, burned and expanded on the same
expansion stroke of the expansion piston 30,
20

power tothecrankshaft

16.

transmitting

The combustion products

arethen discharged on the exhaust stroke.
As

shown

XovrC std Int std,
negative IMEP)
25

valve

and

in

FIG.

2

graph

the greatest pumping losses

thisintakevalve

arrangement

Therefore,itdeactivation30(in terms ofoccur in the AE and AEF modes if the XovrC
are

operated

with(e.g., the timing used for the EF mode).
inlabeled:

is

is

also

increaseapparent

that

necessarytostandard

timing

The pumping losses
withenginecompression

minimizeor

speed.
cylindersubstantiallyreduce pumping work performed by the compression piston.
Referring
XovrC_open Int_clsd,
XovrC

valve

is

kept

to

FIG.

2

graph

labeled:the pumping losses are reduced if the
open

and

the

intakeSUBSTITUTE SHEET (RULE 26)

valve

is

kept

wo 2011/115870

PCT/US2011/028281

21

closed.
inIn this arrangement,

compressed

air

from

the

the compression piston draws
crossoverpassageduringtheintake stroke and pushes this air back into the crossover
passage during the compression stroke.
5

intakeair enters the compression cylinder.
Referring10

No ambient

to

FIG.

2

graph

labeled:

XovrC_clsd_Int_clsd,

the pumping losses are further reduced

if

both

the

XovrC

valve

closed.

In

thisarrangement,

compression

cylinderdecompressed

by

the

large air spring.

and

is

the

intake

the

valve

air

kept

in

the

present

cyclicallycompression

arecompressedpiston

in

the

and

form

of

a

However, the geometric compression ratiosof the compression cylinder 12 and piston 20 are very high(e.g.,
15

in excess .ofcompression

work

40

is

to
lost

1).

Accordingly,

toanmuch ofexcessive

the

heat

of

compression.
Referring
XovrC clsd_Int std,

to
the

FIG.
pumping2

graphlossesarelabeled:reducedeven

further if the XovrC valve is kept closed while the intake
20

valve

is

operatedarrangement,

the

with

standard

compression

timing.

cylinder

is

In

this

in

fluid

communication with the intake port during the intake strokeofthecompression

compression
25

cylinderpiston,
is

and

the

compressed

airduringpresent

in

the

the

compression

graphlabeled:piston's compression stroke.
Referring

to

FIG.

XovrC clsd_Int_open,asdiscussed

2

earlier,thepumping

losses are the lowest if the XovrC valve is kept closed andthe30

intake valve

is

kept

open.

In

this

arrangement,

thecompression piston draws in intake air from the intake port
during its intake stroke and pushes the air back into theintake port during its compression stroke.
of compression work is done since theA minimum amountintake valve

SUBSTITUTE SHEET (RULE 26)

18

iswo 2011/115870

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22closed only in response to avoiding contact with compression
piston 20.

Additionally, most of that compression work isreversible when the opening and closing timings
valve 18 are substantially symmetrical5of intakerelative to TDC of

the compression piston 20.
Althoughtheinventionreference to a specific embodiment,

has

been

described

byit should be understoodthat numerous changes may be made within the spirit and scope
of
10

the

inventive

concepts

described.

Accordingly,itisintended that the invention not be limited to the describedembodiment,

but that it have the full scope defined by thelanguage of the following claims.

SUBSTITUTE SHEET (RULE 26)

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23
CLAIMS

What is claimed is:

1.
5

A split-cycle air-hybrid engine comprising:a crankshaft rotatable about a crankshaft axis;acompression piston

compression
crankshaft

cylinder
such

that

slidablyandoperatively

thecompression

received withinconnected

pistontoathe

reciprocatesthrough an intake stroke and a compression stroke during a10

single rotation of the crankshaft;an intake valve selectively controlling air flow
into the compression cylinder;
an

15

expansion

expansion

cylindercrankshaft

suchpistonandthat

slidably

operatively

theexpansion

received withinanconnected

thepistontoreciprocatesthrough an expansion stroke and an exhaust stroke during_asingle rotation of the crankshaft;crossovera. 20

passageinterconnecting

thecompression and expansion cylinders,the crossover passage

including ."-a(XovrC)

crossovercrossover

expansion

compression(XovrE)

valve

valve

and

a

pressuredefiningachamber therebetween;ancrossover25

airreservoir

passageandoperatively

selectively

connected

operable

to

to

the
store

compressed air from the compression cylinder and to delivercompressed air to the expansion cylinder; andan air reservoir valve selectively controlling air
flow into and out of the air reservoir;
the engine being operable in an Air Expander (AE)30

mode and an Air Expander and Firing (AEF) mode, wherein,inthe AE and AEF modes, the XovrC valve is kept closed during
an entire rotation of the crankshaft,and the intake valve

SUBSTITUTE SHEET (RULE 26)

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24
is

kept

open

for

at

least

240

CA

degrees

of

the

same

rotation of the crankshaft.
2.
wherein,5

The split-cycle air-hybrid engine of claim 1,

in the AE and AEF modes,

the intake valve is kept

open for at least 270 CA degrees of the same rotation of the
crankshaft.
3.
wherein,

The split-cycle air-hybrid engine of claim 1,

in the AE and AEF modes,

the intake valve is kept

open for at least 300 CA degrees of the same rotation of the10

crankshaft.
4.

The split-cycle air-hybrid engine of claim 1,

wherein,in the AE

ratio atanand AEF modes,

intake valvearesidual

closing position iscompression
20

to

1 or

less.
15

5.

The split-cycle air-hybrid engine of claim 1,

wherein,in the AE and AEF modes,

ratio atanintakearesidualvalve closing position iscompression
10

to

1 or

less.
6.
20

wherein,

The split-cycle air-hybrid engine of claim 1,

in the AE and AEF modes,

the intake valve closing

position and intake valve opening position are symmetrical,
within

plus

or

minus

10

CA

degrees,

about

the

top

dead

center position of the compression piston.
7.
25

wherein,

The split-cycle air-hybrid engine of claim 1,

in the AE and AEF modes,

the intake valve closing

position and intake valve opening position are symmetrical,
within plus or minus 5 CA degrees, about the top dead center
position of the compression piston.
8.
30

wherein,

The split-cycle air-hybrid engine of claim 1,

in the AE and AEF modes,

the intake valve closing

position and intake valve opening position are symmetrical,
within plus or minus 2 CA degrees, about the top dead center
position of the compression piston.

SUBSTITUTE SHEET (RULE 26)

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25
9.
wherein,

The split-cycle air-hybrid engine of claim 1,

in the AE and AEF modes,

the intake valve is kept

open during the entire same rotation of the crankshaft.
10.
5

wherein,

The split-cycle air-hybrid engine of claim 1,

in the AE mode,

the air reservoir valve is open,

and compressed air from the air reservoir is admitted to the
expansion cylinder, at the beginning of an expansion stroke,
the

air

is

expanded

expansion piston,
10

on

the

same

expansion

strokeofthetransmitting power to the crankshaft,andthe air is discharged on the exhaust stroke.
11.
wherein,

The split-cycle air-hybrid engine of claim 1;

in the AEF mode,

the air reservoir valve is open,

and compressed air from the air reservoir is admitted to the
expansion
15cylinderexpansion stroke,
the

same

with

fuel,

which is ignited,

expansion

strokepower

thetransmitting

at

to

of

the

beginningofanburned and expanded ontheexpansion

crankshaft,

and

the

piston,combustion

products are discharged on the exhaust stroke.
12·.
20

A split-cycle air-hybrid engine comprising:a crankshaft rotatable about a crankshaft axis;acompression

compression
crankshaft

cylinder
such

that

pistonslidablyreceivedandoperatively

connected

thecompression

through an intake stroke and a25

pistonwithinato · thereciprocatescompression stroke during asingle rotation of the crankshaft;an intake valve selectively controlling air

flowfrom an intake port into the compression cylinder;
an30

expansion

expansion

cylindercrankshaft

such

that

pistonandtheslidablyreceived

withinanoperatively

connected

totheexpansion

pistonreciprocatesthrough an expansion stroke and an exhaust stroke during asingle rotation of the crankshaft;

SUBSTITUTE SHEET (RULE 26)

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26
a

5

crossoverpassageinterconnecting

thecompression and expansion cylinders,the crossover passage

includinga(XovrC)

crossover

expansion

crossovercompression(XovrE)

valve

valve

and

a

pressuredefiningachamber therebetween;ancrossoverairreservoir

passageandoperatively

selectively

connected

operable

to

to

the
store

compressed air from the compression cylinder and to delivercompressed air to the expansion cylinder; and10

an air reservoir valve selectively controlling air
flow into and out of the air reservoir;
the engine being operable in an Air Expander
mode and an Air Expander and Firing(AE)(AEF) mode, wherein,inthe AE and AEF modes, the XovrC valve is kept closed during
15

an entire rotation of the crankshaft,and the intake valve

is opened at a position at which pressure in the compression
cylinder is approximately equal to pressure in theintake

port.
13.
20

A

methodofoperatingasplit-cycle

air-hybrid engine including:a crankshaft rotatable about a crankshaft axis;acompression

compression
crankshaft
25

cylinder
such

that

pistonslidablyandoperatively

thecompression

received withinconnected

pistontoathe

reciprocatesthrough an intake stroke and a compression stroke during asingle rotation of the crankshaft;an intake valve selectively controlling air flow
into the compression cylinder;
an30

expansion

expansion

cylindercrankshaft

such

that

pistonandtheslidably

operatively
expansion

received withinanconnected

thepistontoreciprocatesthrough an expansion stroke and an exhaust stroke during asingle rotation of the crankshaft;

SUBSTITUTE SHEET (RULE 26)

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27crossovera5interconnecting

passagethecompression and expansion cylinders,the crossover passage

includinga(XovrC)

crossover

expansion

crossovercompression(XovrE)

valve

valve

and

a

pressuredefiningachamber therebetween;ancrossoverairreservoir

passageandoperatively

selectively

connected

operable

to

to

the
store

compressed air from the compression cylinder and to delivercompressed air to the expansion cylinder; and10

an air reservoir valve selectively controlling air
flow into and out of the air reservoir;
the engine being operable in an Air Expander(AE)

mode and an Air Expander and Firing (AEF) mode;the method including the steps of:15

keeping the XovrC valve

closed during

an entire

rotation of the crankshaft; andkeeping the intake valve open during at least 240
CA degrees of the same rotation of the crankshaft;whereby the compression cylinder is deactivated to20

reduce pumping work performed by the compression piston on
intake air.
14.
keepingtheThe method of claim 13, including the step ofintakevalve

closing

positionvalve opening position symmetrical,
25

CA

degrees,

about

the

top

dead

and

the

intakewithin plus or minus 5centerpositionofthecompression piston.

keeping

15.

The method of claim 13, including the step oftheintake

valve

open

duringtheentiresamerotation of the crankshaft.
30

16.
closing theratio at the

The method of claim 13, including the step ofintake valve such thataresidual compression

intake valve closing position

less.

SUBSTITUTE SHEET (RULE 26)

is 20 to1 or

wo 2011/115870

PCT/US2011/028281

28
17.

The method of claim 13, further including thesteps of:opening the air reservoir valve; andoperating the engine in the AE mode by admitting
5compressed

air

from

the

air

reservoir

totheexpansion

cylinder, at the beginning of an expansion stroke, expanding
the

air

on

piston,thesametransmitting

expansion
powerstroke

to

the

of

the

expansion

crankshaft,anddischarging the air on the exhaust stroke.
1018.

The method of claim 13, further including thesteps of:opening the air reservoir valve; andoperating the engine in the AEF mode by admitting
compressed
15

air

from

the

air

reservoir

totheexpansion

cylinder with fuel, at the beginning of an expansion stroke,
which is ignited, burned and expanded on the same expansion
stroke of the expansion piston,
cra'nkshaft,transmitting power to theand discharging the combustion products on theexhaust. stroke.

SUBSTITUTE SHEET (RULE 26)

wo 2011/115870

PCT/US2011/028281

1/2

FIG. 1

:.;;
0
N
0

Fig. 2......
......
......
......

-Ut

QCI

-..l
0

Compressor cylinder deactivation
0.0

Compressor deactivation-IMEP
1--

-

-

-

-1 - - - - --- --...

..••...••.....• •.............. ...
·•·•·•·•··•·•· •·•··•··•·••·••· ••..•..•...•...•-0.5------ ------- ------ ------ ------ -------1\..)-1.0
IMEP (bar)r--.. .............

_..........

-1.5

1\..)

................. r- ... _-.............r- ..........

- - - - - ) overC

stc - lnt- std- - - ) overC cis d- lnt- std... ...........

r-- ...

-2.0 ............ ·I ~.overv_c1s p_1m_c1sa~~-·) overC cis d_lnt_ope~- - - - - ) overC_op ~n lnt cis~

-

-2.5
1000

................

............

-..........

.......... ...

'"d('""')

g
00

1500

2000

2500

3000

Engine RPM

3500

4000

N
0

......
......

0N

QCI

N

QCI

......

INTERNATIONAL SEARCH REPORTInternational application No.
PCTIUS 11/28281

A.

CLASSIFICATION OF SUBJECT MATTER

IPC(8}- F02B 25/00,33/22,41/06 (2011.01}
USPC- 123/?0R
According to International Patent Classification {IPC) or to both national classification and IPC
B.

FIELDS SEARCHED

Minimum documentation searched (classification system followed by classification symbols)
IPC(8): F02B 25/00,33122,41/06 (2011.01)
USPC: 123170R
Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched
IPC(8): F02B 25/00,33122,41/06 (2011.01 ); USPC: 123/68, 70R; 60n12,597 - term limited -Electronic data base consulted during the international search (name of data base and, where practicable, search terms used)
Google Scholar; Google Patent; PubWest (US Patents full-text, US PGPubs USOC, full-text, EPO Abstracts, and JPO Abstracts) -Search Terms Used: tension, tensioning, tensions, tensioned, hydraulic, hydraulics, bolt, bolts, stud, studs, fastener, fasteners, piston,pistons, seal, sealed, sealing, seals, angle, angles, etc.

c.

DOCUMENTS CONSIDERED TO BE RELEVANT

Category•

Citation of document, with indication, where appropriate, of the relevant passages

Relevant to claim No.

A

US 2009/0266347 A1 (SCUDERI et al.) 29 October 2009 (29.1 0.2009) entire document
especially Fig. 1, Fig. 3; abstract; para [0009)- [0015), [0034), [0037) - [0038], [0055]- [0056],[0089), [0095], [01 00)

1-18

A

US 4,359,979 A (DOLZA) 23 November 1982 (23.11.1982) entire document generally

1-18

A

US 7,628,126 B2 (SCUDERI) 08 December 2009 (08.12.2009) entire document generally

1-18

A

US 2003/0014971 A1 (SCUDERI) 23 January 2003 (23.01.2003) entire document generally

1-18

A

US 2004/0255882 A1 (BRANYON et al.) 23 December 2004 (23.12.2004) entire document
generally

1-18

A

US 2007/0157894 A1 (SCUDERI et al.) 12 July 2007 (12.07.2007) entire document generally

1-18

A

US 2008/0105225 A1 (SCUDERI et al.) 08 May 2008 (08.05.2008) entire document generally

1-18

A

US 2008/0202454 A1 (PIRAULD 28 August 2008 (28.08.2008) entire document generally

1-18

A

US 2009/0038596 A1 (PI RAULT et al.) 12 February 2009 (12.02.2009) entire document
generally

1-18

A

US 2009/0038598 A1 (PHILLIPS) 12 February 2009 (12.02.2009) entire document generally

1-18~ Further documents are listed in the continuation of Box C.
•

"A"
"E"
"L"

"0"

"P"

D

Special categories of cited documents:"T' later document published after the international filing date o~riority
date and not in conflict with the aphlication but cited to un erstanddocument defining the general state of the art which is not considered
the principle or theory underlying t e invention
to be of particular relevanceearlier application or patent but published on or after the international "X" document of particular relevance; the claimed invention cannot be
filing dateconsidered novel or cannot be considered to involve an inventive
step when the document is taken alone
document which may throw doubts on priority claim(s) or which iscited to establish the publication date of another citation or other "Y" document of particular relevance; the claimed invention cannot be
special reason (as specified)considered to involve an inventive step when the document iscombined with one or more other such documents, such combination
document referring to an oral disclosure, use, exhibition or othermeansbeing obvious to a person skilled in the art
document published prior to the international filing date but later than "&" document member of the same patent family
the priority date claimed

Date of the actual completion of the international search
06 May 2011 (06.05.2011)
Name and mailing address of the ISAIUS
Mail Stop PCT, Attn: ISA/US, Commissioner for Patents
P.O. Box 1450, Alexandria, Virginia 22313-1450
Facsimile No. 571-273-3201
Form PCT/ISA/210 (second sheet) (July 2009)

Date of mailing of the international search report

1 7 MAY 2011
Authorized officer:
Lee W. YoungPCT Helpdesk: 571·272·4300
PCT OSP: 571·272·7774

INTERNATIONAL SEARCH REPORTInternational application No.
PCT/US 11/28281

C (Continuation).
Category•

DOCUMENTS CONSIDERED TO BE RELEVANT

Citation of document, with indication, where appropriate, of the relevant passages

Relevant to claim No.

A

US 2009/0301086 A1 (RALSTON) 10 December 2009 (10.12.2009) entire document generally

1-18

A

US 2006/0124085 A1 (Luttgeharm) 15 June 2006 (15.06.2006), entire document.

1-18

A

US 2004/0139934 A1 (Patton) 22 June 2004 (22.06.2004), entire document.

1-18

A

US 4,630,447 A (Webber) 23 December 1986 (23.12.1986), entire document.

1-18

A

US 2007/0017203 A1 (Zajac) 25 January 2007 (25.01.2007), entire document, esp., para
[0082).

1-18

Form PCTIISN210 (continuation of second sheet) (July 2009)