(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

4 November 2010 (04.11.2010)

WO 2010/126849 A1

PCT(51) International Patent Classification:
F02B 75120 (2006.01)(21) International Application Number:
PCT/US2010/032472(74) Agents: FILDES, Christopher, J. et al.; Fildes & Outland, P.C., 20916 Mack Avenue, Suite 2, Grosse Point
Woods, MI 48236 (US).

(81) Designated States (unless otherwise indicated, for every
kind of national protection available): AE, AG, AL, AM,(22) International Filing Date:
AO, AT, AU, AZ, BA, BB, BG, BH, BR, BW, BY, BZ,
27 April2010 (27.04.2010)
CA,CH,CL,CN,CO,CR,CU,CZ,DE,DK,DM,DO,
DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT,(25) Filing Language:
EnglishHN, HR, HU, ID, IL, IN, IS, JP, KE, KG, KM, KN, KP,(26) Publication Language:
EnglishKR, KZ, LA, LC, LK, LR, LS, LT, LU, LY, MA, MD,
ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI,(30) Priority Data:
NO, NZ, OM, PE, PG, PH, PL, PT, RO, RS, RU, SC, SD,
61/215,146
I May 2009 (01.05.2009)us
SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, TR,(71) Applicant (for all designated States except US): SCUDTT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW.
ERI GROUP, LLC [US/US]; llll Elm Street, Suite 33,(84) Designated States (unless otherwise indicated, for every
West Springfield, MA 01089 (US).
kind of regional protection available): ARIPO (BW, GH,(72) Inventor: PHILLIPS, Ford; 9303 Strong Box Way, San
GM, KE, LR, LS, MW, MZ, NA, SD, SL, SZ, TZ, UG,
Antonio, TX 78254 (US).
ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, MD, RU, TJ,
TM), European (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, SE, SI, SK, SM,[Continued on next page](54) Title: SPLIT -CYCLE ENGINE WITH DUAL SPRAY TARGETING FUEL INJECTION
84-;;;;;;;;;;;;;;;

68;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

Figure 4(57) Abstract: An engine includes a rotatable crankshaft
and an expansion piston slidably received within an expansion cylinder and operatively connected to the
crankshaft. A crossover passage including walls connects
a source of high pressure gas to the expansion cylinder. A
crossover expansion (XovrE) valve is operable to control
fluid communication between the crossover passage andthe expansion cylinder. The XovrE valve includes a valve
head and a valve stem extending from the valve head. A
fuel injector operable to inject fuel into the crossover passage includes a plurality of spray holes disposed in a nozzle end and aimed at an at least one target at which fuelemitting from the spray holes is directed to form at least
one spray pattern. The at least one target is located above
a seated position of the XovrE valve head and between
the walls of the crossover passage and the XovrE valvestem.

W0 2010/12 684 9 A 1 11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
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))

wo 2010/126849

PCT/US2010/032472

1
SPLIT-CYCLE ENGINE WITH DUAL SPRAY TARGETING FUEL INJECTIONTECHNICAL FIELD

The
combustion
5

present

inventionengines.

invention

relates

More
to

a

relates

specifically,

split-cycle

enginetointernal

thepresent

havingfuelinjectors which produce dual spray patterns.

BACKGROUND OF THE INVENTION

10

For
engine"aspurposes

used

in

of

the

clarity,present

theterm "conventional

applicationreferstoaninternal combustion engine wherein all four strokes of thewell-known

Otto

cycle

and exhaust strokes)
15

(the

intake,compression,

expansion

are contained in each piston/ cylinder

combination of the engine.

Each stroke requires

one half

revolution of the crankshaft (180 degrees crank angle
and two full revolutions of the crankshaft
arerequiredtocompletetheentireOtto(CA)),(720 degrees CA)
cycle

in

each

cylinder of a conventional engine.
20

Also,

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 engine comprises: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;wo 2010/126849

PCT/US2010/032472

2anwithinexpansionan expansion(power)cylinderpistonslidablyreceived

and operatively connected tothe crankshaft such that the expansion piston reciprocatesthrough an expansion stroke and an exhaust stroke during a5single rotation of the crankshaft; anda10crossoverpassageinterconnecting

thecompression and expansion cylinders,the crossover passage

includinga(XovrC)

crossover

expansion

crossovercompression(XovrE)

valve

valve

and

a

pressuredefiningachamber therebetween.
UnitedStates

2003 to Carmelo J.

patentScuderi

6,543,225

granted April(the Scuderi patent)

8,

and UnitedStates patent 6,952,923 granted October 11, 2005 to David P.
Branyon
15

et

al.

(the

extensive

discussion

engines.

In

Branyonof

addition,

patent)each

split-cycle
theScuderiandandcontains
similarBranyonantype

patents

disclose details of prior versions of engines of which thepresent invention comprises a further development.
Scuderi20

patentandtheBranyonpatentBoth theareincorporated

art

split-cycle

herein by reference in their entirety.
Referring

to

FIG.

1,

a

prior

engine of the type similar to those described in the Branyon
and Scuderi patents is shown generally by numeral
split-cycle engine
25

conventional

8 replaces

engine with a

two

8.

The

adjacent cylindersof acombination ofcylinder 12 and one expansion cylinder 14.

one

compression

A cylinder head

33 is typically disposed over an open end of the expansion
andcompression

cylinders

12,

14

to

cover

of

the

Otto

and

seal

the

cylinders.
30

The

four

strokes

cycle

are

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

performtheintakeandcompression

strokes,andthewo 2010/126849

PCT/US2010/032472

3

5expansion

cylinder14,

expansion

pistonstrokes.

The Otto cycle is therefore completed in these twocylinders

12,

30,

14

together

perform

once

per

with

the

its

expansion

crankshaft

16

associatedandexhaustrevolution(360

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

disposedinthecylinder12cylinderhead(opening inward into
10

thethrough33.

cylinder)anintakeport

Aninwardly

opening

poppetintake valve

19

18

controls fluid communication between the intake port 19 andthe compression cylinder 12.
During15

piston20

chargeintothecompression

pressurizes
the

the

air

stroke,chargecrossover passage

the

and

compression

drives(or port)

typically disposed in the cylinder head 33.

22,

the

air

which

is

This means thatthe compression cylinder 12 and compression piston 20 are asourceof high pressure

gas

to

the

crossover passage

22,

which acts as the intake passage for the expansion cylinder
14.
20

In some embodiments,

two or more crossover passages 22

interconnect the compression cylinder 12 and the expansion
cylinder 14.
The
compression

volumetriccylinder

12ofcompression

ratio

split-cycle

engine

8

of

the

(and

for

split-cycle engines in general) is herein referred to as the25"compression

ratio"

ofthesplit-cycle

engine.

The

volumetric compression ratio of the expansion cylinder 14 ofsplit-cycle
general)engine8(andasplit-cycle

enginesinis herein referred to as the "expansion ratio" ofthe split-cycle engine.
30

forcylinderiswellenclosed(or trapped)

recesses)whenbottom deadacenter

The volumetric compression ratio of

known

in

the

art

as

the

volume in the cylinder

piston
(BDC)

ratio

the

(including allreciprocating

thereinposition

the

to

of

is

at

its

enclosed volume

wo 2010/126849

PCT/US2010/032472

4(i.e.,

clearance volume)in the cylinder when the piston is

at

top

(TDC)

its

dead center

position.

Specifically for

split-cycle engines as defined herein, the compression ratioof a compression cylinder is determined when the XovrC valve
5

isclosed.

Also,

specifically for

split-cycle engines

asdefined herein, the expansion ratio of an expansion cylinder
is determined when the XovrE valve is closed.
Due to very high compression ratios
1,
10

30

to

1,

40

to

1,

(opening outward away
compression(XovrC)orgreater) ,

from

the

an

(e.g.,

outwardly

cylinder)poppet20 toopening

crossovervalve 24 at the crossover passage inlet

25 is used to control flow from the compression cylinder 12
into the crossover passage 22.
ratios15(e.g.,

20

to 1,

30 to 1,

40

to 1,

or greater),outwardly opening poppet crossover expansion
26

at

flow

the

outlet 27

from

the

cylinder 14.

of

the

(XovrE)crossover passage

passage

22

into

22

an

valve

controls

theexpansion

The actuation rates and phasing of the XovrC

crossover(typicallythecrossoverand XovrE valves 24,
20

Due to very high expansion

20

26 are timed to maintain pressure inpassagebar

22

absolute

at

a

high

or

higherminimumduringpressure
full

load

operation) during all four strokes of the Otto cycle.
Atleast onefuelinjector 2 8 injects

fuel

into

the pressurized air at the exit end of the crossover passage
25

22 in correspondence with the XovrE valve 26 opening, which
occursshortly before expansion piston 30
The air I fueldead center position.

reaches

its

topcharge usually entersthe expansion cylinder 14 shortly after expansion piston 30

30

reaches its top dead center position(TDC),

although it may

begin

under

some

entering

conditions.

slightly

beforeTDC

operatingAs piston 30 begins its descent from its top

dead center position,

and while the XovrE valve 26 is still

open, spark plug 32, which includes a spark plug tip 39 that

wo 2010/126849

PCT/US2010/032472

5
protrudes into cylinder 14,

is fired to initiate combustionin the region around the spark plug tip 39.

Combustion canbe initiated while the expansion piston is between 1 and 30
degrees CA past its top dead center
5

preferably,(TDC)

position.

More

combustion can be initiated while the expansion

pistonisbetweencenter(TDC)

5

and 25

position.

degrees

CA past

Most preferably,

its

top

dead

combustion can beinitiated while the expansion piston is between 10 and 20
degrees
10

CA

past

Additionally,

its

top

combustion

ignition devices

deadcenterbeinitiatedmay

and/ or methods,

microwave ignition devices(TDC)

position.

throughothersuch as with glow plugs,

or through compression ignition

methods.
The XovrE valve 26 is closed after combustion is15

initiatedbut

beforetheresultingenter the crossover passage 22.

combustion

event

can

The combustion event drives

the expansion piston 30 downward in a power stroke.
Duringtheexhauststroke,exhaust

gases

are

pumped out of the expansion cylinder 14 through exhaust port
20

35 disposed in cylinder head 33.
exhaust valve 34,
port 35,

An inwardly opening poppet

disposed in the inlet 31 of the exhaust

controls fluid communication between the expansion

cylinder 14 and the exhaust port 35.
With the split-cycle engine concept, the geometric
25

engineparameters

length,volumetriccompression

30(i.e.,

12

and

bore,

stroke,connecting

rodcompression

ratio,

etc.)

the

expansion

14cylindersareofgenerally

independent from one another.

For example, the crank throws

36,

cylinder37forcylinder 14,

thecompression

12

and

expansionrespectively, may have different radii and may

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.

This independence enables the split-

wo 2010/126849

PCT/US2010/032472

6

cycle

engine8topotentiallyachievehigherefficiency

levels and greater torques than typical four stroke engines.
The geometric independence of engine parameters inthe split-cycle engine 8 is also one of the main reasons why
5pressure can be maintained in the crossover passage 22

asdiscussed earlier.

30

reaches

its

Specifically,

top

dead

centertheexpansion piston

position

prior

to

the

compression piston 20 reaching its top dead center position
by a discreet phase angle (typically between 10 and 30 crank
10

angle

degrees).

This

phase

angle,

togetherwithpropertiming of the XovrC valve 24 and the XovrE valve 26, enables
thesplit-cycle

engine8tomaintainpressurecrossover passage 22 at a high minimum pressure

in

the

(typically

20 bar absolute or higher during full load operation) during
15

all four strokes of its pressure/volume cycle.

That is, thesplit-cycle engine 8 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
20

rotation)

during which

thecompression piston

2 0 simultaneously ascends

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

are

both

transferred

open,
( 1)

a

from thetotheperiod,from

expansion

equal

mass

of

gas

is

into

the

from the crossover passage 22
14.

Accordingly,

duringthisthe pressure in the crossover passage is prevented

dropping(typicallyoperation) .
intakecylinderits

During the period ofcompression cylinder 12
(2)

from

that the crossover valves 24,

substantiallycrossover passage 22 and30

30

descends from its TDC position towards its BDC position andthe25

expansion piston

and

20,

below

a

predetermined

minimum

30,

40

bar

duringorMoreover,exhaustabsolutepressure
full

load

during a substantial portion of thestrokes(typicallyintake and exhaust strokes or greater),

90%

of

the

entirethe XovrC valve 24

wo 2010/126849

PCT/US2010/032472

7

and XovrE valve 26 are both closed to maintain the mass oftrapped gas in the crossover passage 22 at a substantiallyconstant level.

As a result,the pressure in the crossover

passage 22 is maintained at a predetermined minimum pressure
5

duringallfourstrokesoftheengine'spressure/volume

cycle.
XovrE valve 26 opens shortly before the expansion

10

piston30

reaches

its

time,

the

pressure

top dead center position.

ratio

of

the

pressure

At

ln

this

crossoverpassage 22 to the pressure in expansion cylinder 14 is high,due to the fact that the minimum pressure in the crossover
passageistypically

engine

load

and

the

20

bar

absolutepressure

in

or

the

higherexpansion

at

full

cylinderduring the exhaust stroke is typically about one to two bar
15absolute.
pressure

In other words,
incrossoverwhen XovrE valve 26 opens,

passage22

issubstantiallythehigherthan the pressure in expansion cylinder 14 (typically in theorder of 20 to 1 or greater at full engine load)pressure ratio causes
20

initialThis highflow of the air and/or fuelcharge to flow into expansion cylinder 14 at high speeds.
These high flow speeds can reach the speed of sound,isreferred

to

as

sonic

flow.

This

sonic

which

flow

is

particularly advantageous to split-cycle engine 8 because it
causes25

arapid combustion event,cycle engine

which enables

thesplit-

8 to maintain high combustion pressures eventhough ignition is initiated while the expansion piston 30
is descending from its top dead center position.
The

fuel

injectors

28

have

a plurality of sprayholes disposed in the nozzle end of the fuel30

injectors 28

which are targeted to produce one or more generally conicalspray patterns.

However,

injectors

28

and

spray

assuring

thepropervariousholedeliveryparameters

of

the

fuel
for

targetingarecritical

of

to

the

fuel

expansion

wo 2010/126849

PCT/US2010/032472

8cylinder, wherein variations in these parameters can result
in

less

than

optimalparameters include,size
5(i.e.,

locationoffueldelivery.

Somebut are not limited to,diameter)

of

the

hole

spray

spray

holes,

targets

theproduced by

thespray holes,

and

the

numberspray

injector operating pressures and temperatures,
size

these

the number and
the

of

of

and

holes,

fuel droplet

timingoftheapparatusforinjectors.

SUMMARY OF THE INVENTION

10

The

present

inventionand method of injecting fuel15

providesaninto an engine wherein sprayholes of the engine's

fuelinjectors are aimed at certain

targetsfuel

spraystoproducethatenhanceengineperformance.
More particularly,

an exemplary embodiment of anengine in accordance with the present invention includes acrankshaft rotatable about a crankshaft axis.
20

piston is slidably received within an expansion cylinder andoperatively

connected

totheexpansion

pistonisoperable

expansion

stroke

and

an

walls

connectsaexpansion cylinder.
operabletocrossoverpassagecrankshaft
toexhaustrotation of the crankshaft.
25

An expansion

sourcereciprocate
strokeandthethroughanasingleA crossover passage including
of

fluid
the

that

duringhighpressure

A crossover expansion

controlsuch(XovrE)

communication

expansiongascylinder.

tothevalve isbetween

the

The

XovrE

valve includes a valve head and a valve stem extending from30

the valve head.

A fuel injector is operable to inject fuelinto the crossover passage.

The fuelplurality of spray holes disposed in a

injector includes anozzle end of thefuel injector and aimed at an at least one target at whichwo 2010/126849

PCT/US2010/032472

9

fuel emitting from the spray holes is directed to form atleast one spray pattern.

The at least one target is locatedabove a seated position of the XovrE valve head and between
the walls of the crossover passage and the XovrE valve stem.
5

The XovrE valve may be an outwardly opening valve.
The spray holes may be aimed at a plurality of spray targets
toform aplurality ofspray patterns,

thetargets

being

located such that the spray patterns straddle the valve stemof the XovrE valve.
10

Each spray hole may have a centerline

extending therethrough,the plurality of spray holes beingoriented such that the spray hole centerlines pass through
the

15

at

least

one

target

at

which

fuel

emitting

from

the

spray holes are aimed.

One of the at least one target may

betargetanoutsidediameterlocated at

a

point

on

the

centerline of one spray hole of the plurality of spray holes
at

which

the

centerline

intersectsadiameter of the XovrE valve head whenmaximum

outsidethe XovrE valveisraised a predetermined target lift distance above its seatedposition.
20

The target lift distance may be within a range of

10 to 60 percent of maximum XovrE valve lift, preferably 15
to40

percentofmaximum

XovrE

valve

lift,

and

more

preferably 20 to 30 percent of maximum XovrE valve lift.
The

spray hole

independently oriented.
25

centerlines

may besubstantially

The number of spray patterns may

equal the number of spray targets.
The crossover passage may be a helical crossover
passageincluding a helical end section disposed over the

XovrE valve.

The at least one target may be located within

the helical end section.
30

The helical end section may spiralin one of a clockwise or a counterclockwise direction.
Thesourceofhighpressure

gas

may

be

a

compression cylinder including a compression piston slidably
received therein, the compression cylinder being operatively

wo 2010/126849

PCT/US2010/032472

10connected to the crankshaft such that the compression piston
is5

operable to reciprocate through an intake stroke and acompression

strokeduringcrankshaft.

The

crossoversinglearotationpassageoftheinterconnects

theexpansion and compression cylinders.
In

another

exemplaryembodiment,

anengineinaccordance with the present invention includes a crankshaft
rotatable about a crankshaft axis.
slidably
10

received

operatively

withinconnected

toAn expansion piston isanexpansionthecrankshaft

expansion

pistonisoperable

expansion

stroke

and

an

to

such

reciprocate

exhaustrotation of the crankshaft.

cylinderstrokethatthethroughanduringasingleA crossover passage connects asource of high pressure gas to the expansion cylinder.
15

crossover
fluid

expansionA

fuelinjector

of

valve

spray

injector.

holes

the

is

operableA

tocontrolcrossover passage

and the

The XovrE valve includes a valve stem.
iscrossover passage.
20(XovrE)

communication between

expansion cylinder.

andoperable
The fuel

disposed

intoinject

fuel

into

the

injector includes a pluralityanozzle

end

of

the

fuel

The spray holes are aimed at two or more targets

at which fuel emitting from the spray holes is directed toform at least two fuel sprays.

The at least two fuel sprays

straddle the valve stem of the XovrE valve.
25

Eachtherethrough.

spray hole may haveacenterline extending

The plurality of spray holes may be oriented

such that each spray hole centerline passes through one of
the targets at which fuel is directed.
the30

spray holes

forming oneof the

The centerlines ofspray patterns may beoriented at a target that is distinct from a target at which
the centerlines of thespray holes

spray patterns are oriented.

forming another of thewo 2010/126849

PCT/US2010/032472

11

The XovrE valve may include a valve head disposedat an end of the valve stem.
outwardly

opening

valve.

The XovrE valve also may be an
One

of

the

targets

may

be

an

outside diameter target located at a point on the centerline
5of at least one of the spray holes at which the centerline
intersectsamaximum outside

diameter

of

the

XovrE

valve

head when the XovrE valve is raised a predetermined target

10

lift distance above its

seated position.

distance

a

may

be

within

range

of

10

to

60

percent

of

to

40

percentofmaximum XovrE

valve

lift,

preferably 15

maximum

valve

lift,

and

XovrE

more

The target lift

preferably

20

to

30

percent of maximum XovrE valve lift.
The crossover passage may be a helical crossover
passage15

including a helical end section disposed over the

XovrE valve.

The two or more targets may be located within

the helical end section.

The helical end section may spiralin one of a clockwise or a counterclockwise direction.
Thesourceofhighpressure

gas

may

be

a

compression cylinder including a compression piston slidably
20

received therein, the compression cylinder being operatively
connected to the crankshaft such that the compression piston
is25

operable to reciprocate through an intake stroke and acompression

strokeduringcrankshaft.

The

crossoversingleapassagerotationoftheinterconnects

theexpansion and compression cylinders.
In
injectinganother

fuel

in

an

exemplaryengineembodiment,
isadisclosed.

methodTheofengineincludes a crankshaft rotatable about a crankshaft axis.

Anexpansion piston is slidably received within the expansion30cylinderand operatively connected tothecrankshaft

suchthat the expansion piston is operable to reciprocate throughan expansion stroke and an exhaust stroke during arotation of the crankshaft.

singleA crossover passage including

wo 2010/126849

PCT/US2010/032472

12

walls

connectsasourceexpansion cylinder.

of

high

A crossover expansion

disposed at an outlet end of the5operabletocrossoverpassagepressurecontrol

fluid

and

the

gas

to

(XovrE)thevalve iscrossover passage and iscommunication

expansion

between

the

The

XovrE

cylinder.

valve includes a valve head and a valve stem extending fromthe valve head.
into

the

crossover passage.

plurality of
10

fuel

A fuel injector is operable to inject fuelspray holes

injector.

targets

Each

which

at

directed to

The

fuel

disposed

ln

a

is

aimed

at

from

the

spray

spray

fuel

form twohole

emitting

injector

spray patterns.

includesnozzle

The twoaend of

the

one

of

two

holes

is

targetsarelocated above a seated position of the XovrE valve head andbetween walls of the crossover passage and the XovrE valve
15

stem such that the spray patterns straddle the XovrE valve
stem.

Injection

of

fuel

is

begun

from

the

fuel

injector

towards the outlet end of the crossover passage.

The XovrE

valve

prior

is

opened.

Injection

of

fuel

is

ended

to

closing the opened XovrE valve.
20

The XovrE valve may be opened outwardly relative
tothebeforeexpansion

Fuelinjection

opening the XovrE valve or after

valve.

The

establishing25

cylinder.

expansion

methodaircylinder

may

flow

furtherfromthroughthe two spray patterns

the
the

be

begun

opening the XovrE

includecrossover
open

may

XovrE

the

steps

passagevalve;

toofthesweeping

into the air flow such that one of

the spray patterns is pulled over and across the XovrE valve
stem and is merged with the other spray pattern to generally
form a single combined spray; and pulling the combined spray30

towards an edge of the outlet end of the crossover passage
wherebythe

combinedthrough the XovrE valve.

spray

exits

the

crossoverpassage

The duration of an injection eventfrom the beginning of fuelinjection to the ending of fuelwo 2010/126849

PCT/US2010/032472

13
injection may be approximately 45 degrees of crank angle or
less, preferably 40 degrees of crank angle or less,and more

preferably 35 degrees of crank angle or less.
These
5

invention will

and
be

other

more

features

fully

and

understoodadvantages
from

the

of

the

followingdetailed description of the invention taken together with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS
10
In the drawings:
FIG.

1 is a cross-sectional view of a conventional

split-cycle engine;
FIG.
15

2 is a perspective view of a helical passage

for linking an inlet manifold to an inlet valve of an engine
cylinder head;FIG.

3 is another perspective view of the helical

FIG.

4 is

passage;20

embodiment

of

a

a

cross-sectional view of an exemplary

split-cycle

engineinaccordance

with

the

present invention taken along the line 4-4 in FIG. 5;
FIG.

5 is a plan view of the split-cycle engine of

FIG.

6 is

FIG. 4;25

a perspective view of a

portion of the

split-cycle engine illustrating an inside of a cylinder headand passages of the engine;
FIG.

7 is a perspective view of a fuel injector of

the split-cycle engine;
FIG.
30

8

is

an

enlarged

front

view

of

the

fuel

of

the

fuel

injector as viewed from the line 8-8 in FIG. 7;
FIG.

9

is

a

cross-sectionalview

injector taken along the line 9-9 in FIG. 8;

wo 2010/126849

PCT/US2010/032472

14

FIG. 10 is a perspective view of the fuel injector
illustrating

fuel

spray

patterns

formedbyejecting

fuelthrough spray holes of the injector;
FIG.
5

11 is a perspective view of a portion of the

split-cycle engine

illustrating

injection

of

fuel

into

the

a perspective view illustrating a

Y-X

engine passages;
FIG.
plane

of

a

12

is

three-dimensional

Cartesiancoordinate

systemsuperimposed over an expansion cylinder of the engine;
10

FIG.

13 is a cross-sectional view taken along theline 13-13 in FIG. 12 illustrating a Y-Z plane of the threedimensional Cartesian coordinate system;
FIG.

14 is a cross-sectional view taken along theline 14-14 in FIG. 12;
15

FIG.
target15

islocation plotanexemplaryembodiment

of

a

spray

illustrating the Cartesian coordinatesof outer diameter (OD) targets and firedeck targets;
FIG.

16 is a plan view of a portion of the split-

cycle engine illustrating an inside of the expansion cylinder
20

and associated passages of the engine;
FIG.

17

is a plan view of the engine of FIG.

16

schematically illustrating the beginning of injection of fuel
spray

into

helicalend

sectionsoftheenginecrossoverpassages;
25

FIG.

18 is a plan view schematically illustrating

the opening of engine valves in the passages

such that air

flow in the passages begins to affect the trajectory of thefuel sprays;
FIG.
30

19 is a plan view schematically illustrating

distortion of the trajectory of the fuel sprays as they areswept into the air flow;

wo 2010/126849

PCT/US2010/032472

15
FIG.

20 is a plan view schematically illustrating

fuel sprays being pulled across a valve stem and beginning tomerge with another fuel spray; andFIG.
5

21 is a plan view schematically illustrating

the merged fuelspraysbeing pulled to

a

far

edge

of thehelical end sections.

DETAILED DESCRIPTION OF THE INVENTION

10Referring
clarity,to2

a helical passage 38

connecting passage
manifoldtoan(port),

inlet

conventional engine.
15

FIGS.

and

3,

for

purposes(as referred to herein)

which

valve

typically linksofacylinder

of

is a

an

inlet

head

in

a

The downstream portion of the helicalpassage 38 includes a generally straight runner section 39
integrally connected to a helical end section 40,

which isdisposed

valve

over

an

inlet

valve

41.

The

inlet

41

includes a stem 42 and a head 43, wherein the head 43 opens
to a cylinder (not shown)
20

end

sectiondescending

25

The flow area within the helical40

isdisposed

funnel44

aroundintheacircumferential

valve

stem

42,

and

which

is

carried ln a bore 46 of the end section 40.

The funnel 44

spirals over at

least one-third of aand preferably

between

and

valve

one-half

stem 42,sothree-quarters

that

incoming

turn,
of

air

a

is

turn,

about

forcedtotherotateabout the valve stem 42 prior to entering the cylinder.

Theroof 47 of the funnel 44 reduces in height as the funnel 44
spirals around the valve stem 42.
The runner section 39 can optionally be oriented
30

tangentiallyororientation

determining

fuel/airchargeoptionally,

eachradiallyasithelicalrelativethebulk

enters
end

to

the

cylinder,flow

directionthecylinder.

section

4 0 mayofspiral

such
the
Also,
in

a

wo 2010/126849

PCT/US2010/032472

16

clockwiseorcounterclockwise

direction,suchrotational

direction determining the direction of rotation or spin thefuel/air charge will have as it enters the cylinder.
Referring to FIGS.
5

indicates

4 and 5,an exemplary embodimentnumeral 50 generally

of asplit-cycle engine

having dual tangential helical crossover passages 78 with afuel injector 90 disposed in the downstream portion of eachcrossoverpassageinvention.
10

78

in

Split-cycle

accordanceengine50

structurally similar to prior art

with
is

the

presentfunctionallyandsplit-cycle engine

8 asillustrated and described in FIG. 1.
Engine 50 includes a crankshaft 52 rotatable abouta crankshaft axis 54 in a clockwise direction as shown in
the figures.
15

displaced

The crankshaft 52 includes adjacent angularly

leadingandfollowing

crank

throws

56,

58

block

64

connected to connecting rods 60, 62, respectively.

20

Engine50

furtherdefiningaofadjacent

engine50

pairincludesexpansion cylindera68

includesacylindercylinders.

compression
closed by aIncylinderparticular,
66

andcylinder head 70

an

at

an

upper end of the cylinders opposite the crankshaft 52.
A compression piston 72 is received in compression
cylinder 66 and is connected to the following connecting rod
62
25

for

centerreciprocation
(TDC)

of

the

pistonand bottom dead center72

between

(BDC)

top

dead

positions.

An

expansion piston 74 is received in expansion cylinder 68 andisconnected to theleading connecting rod 60

forsimilar

TDC/BDC reciprocation.
The30cylinder head70

providesthestructuregas flow into, out of, and between the cylinders 66,
the

order

of

gas

flow,

the

cylinder

head

70

for

68.

In

includesanintake passage 76 through which intake air is drawn into thecompression

cylinder

66,

a

pair

of

tangential

helicalwo 2010/126849

PCT/US2010/032472

17crossover (Xovr) passages 78 through which compressed air istransferred
expansion

from

the

compression

cylinder

68,

and

an

cylinderexhaust

66

to

80

throughpassagethewhich spent gases are discharged from the expansion cylinder
5

68.
Gas

flow

into

the

compression

cylinder66iscontrolled by an inwardly opening poppet type intake valve
82.

Gas flow into and out of each helical crossover passage

78 may be controlled by a pair of outwardly opening poppet
10

valves,i.e.,crossovercompression(XovrC)valves84

atinlet ends of the helical crossover passages and crossover
expansion

15(XovrE)valves86 at outlet ends of the helicalcrossover passages.

Each pair of crossover valvesdefineschamberapressure

respective
exhaust87

crossover passages.

passage

80

is

may

be

actuatedmechanically20

indrivenExhaustcontrolled

poppet type exhaust valve 88.
88

between

by

them
gas

an

any

suitable

cams,

86

their

out

inwardlymanner,variableinflow

These valves 82,

84,

the

opening

84,

86 and

such

as

valve

by

actuationtechnology, or the like.
Each helical crossover passage 78 has at least one
high pressure fuel injector 90 disposed therein.

The fuel

injectors 90 are operative to inject fuel into the charge ofcompressed25

airwithinthepressurechambers

87

of

the

helical crossover passages 78.
Engine 50 also includes one or more spark plugs 92
or other ignition devices.

The spark plugs 92 are located

at

in

the

end

of

the

mixed

fuel

and

air

chargeappropriate

cylinder30

68locationswhereinaexpansionmay

beignited and burned during the expansion stroke.
Referring to FIG.

6,

a close-up view is shown of

the inside of the cylinder head 70 and passages,

includingthe exhaust passage 80 and downstream portions of the dual

wo 2010/126849

PCT/US2010/032472

18

tangential helical crossover passages 78.

Fuel injectors 90

are

of

disposedin

each

downstream portion

thecrossoverpassages 78 to inject fuel into the air stream as the XovrE
valves5

86 areactuated.

As will be discussed in greater

detail herein, the fuel spray (not shown) from the injectors
90 is targeted to optimize the flow and distribution of the
fuel/air charge into the expansion cylinder 68.
As
flow

10

from

cylinderstrokepreviously

the
68

and

discussed,

crossover

where
the

it

fuel/air

78

into

the

expansion

duringtheexpansion

combustionareultimately

passagesisproductsa

combustedofthechargemustdischarged through the exhaust passage 80 during the exhauststroke.

Prior to combustion,

the fuel/air charge must be

rapidly mixed and thoroughly distributed in15

theexpansion

cylinder 68.
Both crossover passages 78 are constructed with agenerally straight tangential runner section 100 integrally

20

connected to a clockwise helical end section 102,

which isdisposed over theoutwardly opening poppet

type

crossoverembodimenteachclockwise

expansion valve 86.
In

the

of

FIG.

6,

helical end section 102 includes a funnel 104 spiraling in aclockwise direction about a valve stem 106 carried in a bore
108, through which the valve stem of each outwardly opening
25

crossover expansion valve 86 extends.

The spiral funnel 104

forces incoming air to rotate about the valve stem 106 prior
toentering

theexpansion

cylinder68.

Thecarries an outwardly opening valve head 109,
closed,30

partially by pressure

valve

stem

which is heldin the pressure chamber

87,

100

to

the

is,

each

when the valve is seated.
Eachperimeterofrunnerthesectionexpansioniscylindertangential
68.

That

runner section 100 directs air flow into the funnel 104 in a

wo 2010/126849

PCT/US2010/032472

19

flow path that is approximately parallel
plus or minus 20 degrees,
degrees,(i.e.,

preferably

more preferably plus or minus 10

and most preferably plus or minus 5 degrees)to atangential line extending through a point in the expansion
5cylinder's 68 perimeter which is closest to the valve stem.
The valve stem 106 carries an outwardly opening valve head
109

which

pressureisheldchamberclosed,87,

partially

when

the

by

valve

pressure

is

in

the

seated.

This

combination of dual tangential helical crossover passages 78
10

in which both helical end sections 102 spiral in the same
direction has been found to greatly promote rapid air/fuelmixinginthedepicts

both

clockwise
15

split-cycle

helicaldirection;end

engine50.

This

sections

102

spiralingmaybehowever,itembodimentinthepreferable

inalternative embodiments for both of the helical end sections
102 to spiral in the counterclockwise direction.
Referring to FIGS. 7,

8 and 9,a perspective viewof an injector 90 is shown in FIG. 7, a close-up front viewof the associated injector tip 120 of injector 90 is shown20

in FIG.

8(as viewed from the line 8-8

in FIG.

7),close-up side view of the tip 120 is shown in FIG.

9, which

is a cross-section taken along the line 9-9 in FIG.

8.

In

this

has

a

exemplaryplurality
25

and a

of

embodiment,
six

injector

circumferentially around an
seen

in

FIG.

illustrated

in

the

injector

spray
injector

tip

holes
tip

120

122

centerdisposed
124

(best

8) .

Althoughsix

injector

holes

are

this

embodiment,anyreasonable

numberofholes may be disposed in injector tip 120 (e.g., 1 through 8
or more).
30

Each injector spray hole 122 may vary in diameter

and/or length, and each hole 122 has a spray hole centerline
126 extending therethrough (best seen in FIG. 9)
Itisimportant

to

note

that

the

centerlines

126

of

122

each

may

be

holes

spray

hole

substantiallywo 2010/126849

PCT/US2010/032472

20
independently oriented(aimed)to direct fuel at a separate

individual target or at a plurality of common targets within
the geometry of the engine 50.
be oriented such that,5

in engine 50,
will

pass

geometry

10

when the fuel injector 90 is mounted

thethroughengine50aspecific

towardtargetwhich

thewithinfuel

theemittingfrom that hole 122 will be directed.

There may be as manytargets

nothingthanasingle target toward which all the holes 122 are aimed,

or

any

as

there

number

of

are

holes

targetsreferringagain

injector

90

to

will

122,

or

therebetween

groups of holes are aimed.

15

the holes 122 may

the extended centerline 12 6 of each hole 122

generallyofThat is,Referring

FIGS.
emit

toward

8 and
fuel

9,

to

each

which

which

variousFIG.

10spray holewill

generally conical fuel spray pattern

more

fan

out

(or fuel spray)

and

122

of

into

a

as thefuel traverses away from the spray hole 122,

provided there

are no external forces

acting on thefuelspraysas(e.g.,

theyarehigh air flow)

being

emitted.

The

numberofconical spray patterns may be equal to the number of targets
20

the holes 122 are aimed at.
there are two targets
three holesisIn this exemplary embodiment,(not shown),

aimed ata

firstin which a first group of
of

the

two

targets

and asecond group of three holes is aimed at a second of the twotargets.
25

Asagroupsofconicalshapedholes

pattern 128,
132,

134,

which

the

sprays

to

form

two

distinct

128

and

130.

combinespray

130 hascenter lines 132,30

result,ispatterns
a

from

each

of

the

two

generally
Each

spray

respective spray pattern centerline

aimed

at

each

target.

That

is,

the

134 extend generally from the injector tip

center 124 of each injector tip 120 toward and through thetarget.
centerMoreover,of

except

from

the

124,

the

134 of each conical spray pattern 128,130

spray hole

centerline 132,

122

for
to

the

small

injector

distance

tip

centerwo 2010/126849

PCT/US2010/032472

21

substantially aligns with each centerline 126 of each sprayhole 122 aimed at the same target.
Onetargets5

skilled in the art would recognize

that

the

through which a plurality of spray holes 122(andtheir center lines 12 6)

are aimed may be so close together

that the fuel sprays from each of the plurality of holes 122
will

combinetospray pattern.

form

a

singledistinct

generally

conicalFor purposes herein, when the sprays combine

to form a single spray pattern, the holes 122 are considered10

to be aimed at the same target.
Referring to FIG.
to FIG.
and

6,

11,

a perspective view,similaris shown of the inside of the cylinder head 70

passages,

includingtheexhaustpassage80

anddownstream portions of the dual tangential helical crossover
15

passages

78.

The

fuel

injectors

90

aredisposeddownstream

portionsofcrossoverpassages

injectors

90 are activated so that they are emitting dual

78.

in

The

the
fuel

fuel sprays 128, 130 across the helical end sections 102 of
the crossover passages
20

78.

The dual

fuelsprays 128,130

are aimed to straddle the valve stems 10 6 of XovrE valves
86.

The injectors are typically designed for gasoline highpressure(e.g., 20-200 bar).

operate

in

the

high

As such,pressure

they are designed to

and

high

temperatureenvironment of the Xovr ports 78.
25

Several factors must be considered when targeting
fuel sprays from an injector for optimal fuel/air flow anddistribution

into

expansion

cylinder68.

Generally,thefuel sprays 128, 130 should be targeted to impinge as little
as possible on cold surfaces and to be directed as much as
30

possible into areas
engine50,

theof maximum air flow.

relatively cold surfaces

walls of the crossover passage 78
sections 102)

In the case oftoavoid arethe(including the helical end

and the valve stems 10 6 of XovrE valves

8 6.

wo 2010/126849

PCT/US2010/032472

22

The

XovrE

valve

heads

109

have

relatively

hotsurfaces.

However, when the XovrE valve heads 109 are seated, they are
generally located away from the main flow path of the air
swirling in helical section 102 and should also be avoided.
5

Accordingly,

the fuel sprays 128, 130 are aimed at a target

located above the seated position of the valve heads 109 andbetween the walls of the helical end sections 102 and thevalve stems 106.
Additionally,
10

importantfactor

Generally,

large

fuel

in

dropletoptimizing

fueldroplets

size

the

anotherfuel/airflow.

greater

momentum but

evaporate more slowly than small fuel droplets.

If the fueldroplets are too large,

have

is

they may carry well into the main

air flow path, but will not evaporate quickly enough and may
15

impingewhere

on thetheycool walls

willof the helical end section

conglomerate

combust properly.

asaliquid

fuel

102

and

not

If the fuel droplets are too small,theywill evaporate quickly, but will not have enough momentum tocarry into the main air flow path and enter the expansion
20

cylinder 68.

Also generally, the larger the number of spraypatterns, for a given charge (mass) of fuel, the smaller the
diameter of the spray holes 122 and the smaller the droplet
size.
In
25

engine

50,

the
dual

exemplaryfuelembodiment

spray pat terns

of

the

split-cycle

12 8,

13 0,

havingtwo

distinct targets, worked best with regards to optimizing thedropletsizes.

That

is,

a

singlespray

patternproduce

droplets

that

were

too big and would

would

impingetoomuch on the cool surfaces of the helical end sections 102.
30

Alternatively,

three

or moredroplets

were

too

that

small

spray pat terns
and

would

not

would produce
haveenoughmomentum to carry across the helical end section 102 and mix

wo 2010/126849

PCT/US2010/032472

23with the main air flow path entering the expansion cylinder
68.
Referring to FIGS.
Cartesian coordinate system5is

12 and 13,

a three-dimensional(having X,

Y and Z coordinates)

superimposed over the engine 50,

over the expansion cylinder 68.
plane(i.e.,

where Z=O)

and more specifically,

FIG. 12 illustrates the Y-X

of the coordinate system.

FIG.

13

is a cross-sectional view taken along the line 13-13 in FIG.
12,
10

and FIG.

13 illustrates the Y-Z planeof the coordinate system.

(i.e.,

where X=O)The Y-Z plane passes through thecenterline 138 of the expansion cylinder 68 as well as thecenterline 139 of the exhaust valve 88.

The origin 136 of

the

where

coordinate

equal
15

0)

is

system(i.e.,

located at

the

the

intersection

138 of expansion cylinder 68
bottomsurfaceflameface)

140

point

of

X,

the

(best seen in FIG.

(generally

known

of the cylinder head 70

as

the

Y and

Z

centerline
13)

and thefiredeckor(also best seen in FIG.

13) .
Referring
20

FIG.

12,

it

can

be

seen

that

the

respective centerlines 132 and 134 of spray patterns 128 and
130,

which

targets

25

to

are

emittedlocated between

wallsof the helical end sections
XovrE

valvessections

86

have

90,

XovrE valve

of

of

end

the

injectors

walls

10 6

helical

from

102.

stems

This

102

are

is

aimed

106 and the
becauseand the valve

relatively

cool

at

the

stems

surfacesandwould hamper the evaporation rates of the fuel emitted frominjectors 90.
132

and

134

Note also,ofthethat if the respective centerlines

spray patterns

128

and

130

are

aimed

between XovrE valve stem 106 and the helical end section 102
30

walls,

then

holes

122

so

too

which

are

combinepattern 128 and 130.

thetocenterlines
form

each

126

of

the

spray

associatedspraywo 2010/126849

PCT/US2010/032472

24

Referring to FIG.

14,

which is a cross-sectionalview taken along the line 14-14 in FIG. 12, for purposes ofsimplicity, only a single spray pattern 130 of the two spraypatterns
5

128 and 130,

which are emitted from the90,

is shown.

As discussed earlier,

spray pattern 130 has

anassociatedcenterline

originates

134

which

center 124 of injector tip 120 and is aimed

10

injectorthrough)towardageometry.

Notetargetalso,

locatedaswithindiscussed

from(i.e.,
theearlier,thepassesengine

50

that

the

centerlines 126 of the spray holes 122 which combine to form
spray patterns 128 and 130 are aimed at the same targets.

targets

15

In

this

embodiment,areutilized.

two

The

alternative

first

type

designated herein asanoutside diameter

and

of

targetthesecond

type

is

of
(OD)

types

of

targetistargetdesignated herein

142,
as

a

firedeck target 144.

Both OD target 142 and firedeck target

144

a

are

locatedatpoint

through

which

the

extended

centerline 134 will pass.
Both targets 142, 144 aim the centerline 134 above
20

the XovrE valve head 109 when the valve head 109 is in its
sea ted position.

That

is,

86

be

raiseddistance

14 6 aboveits

seated position before the maximum

outsidediameter

that

25

the

valve

centerline 134.

of

the

both targets

head

a

142,

14 4 requirepredetermined

109

targetintersects

One of the primary reasons

for

the

lift

aimed

selectingtargets that aim the spray centerline 134 above the seatedposition of the XovrE valve head 109 is to inject the spraypattern 130 into an area of near maximum air flow in orderto promote air/fuel mixing and distribution.
30

In the case of the OD target 142,

the target 142

location is substantially the actual point of intersection
between the maximum outside diameter of XovrE valve head 109
and the aimed centerline 134 when the XovrE valve 86 reaches

wo 2010/126849

PCT/US2010/032472

25
its target lift distance 146.
target 14 4,

In the case of the firedeckthe target 14 4 location is substantially at apoint on the firedeck 140 of cylinder head 70 that the aimed
centerline
5

134

would

pass

throughafterintersecting

ODtarget 142.
The target lift distance 146 is preferably locatedwithin a
lift.

range

of a percentage of maximum XovrE valve

86

It is preferable that the target lift distance 146 bewithin a range of 10 to 60 percent of maximum XovrE valve 86
10

lift.

It is more preferable that the target lift distance146 be within a range of 15 to 40 percent of maximum XovrE
valve 8 6 lift.
distance146

It is most preferable that the target liftbewithin

a

range

of

20

to

30

percentofmaximum XovrE valve 86 lift.
15

By way of example,
valve

86

(i.e.,

if the maximum lift of XovrE

the point at which the XovrE valve

furthest away from its seated position)86

isis between 3. 0 and

3.6 millimeters (mm) and the target lift distance 146 is set
at 0.9 mm,
20

then the lift distance 146 would be set within adesirable range of 25 to 30 percent of the maximum XovrE 86
valve lift.

This would place the spray pattern 130 in good

position to be swept up by the high air flow that occurs inthedownstream

portionofthecrossoverpassage78

whenvalve 86 opens.
25

Referring to FIG. 15, an exemplary embodiment of aspraytargetlocation

Cartesian coordinates

plot

is

(X, Y, Z)presented

of each OD target

150 and 152 and each firedeck target 144,
within30

thecoordinates
injectortip

geometryofforinjector

thecenters

engine124)

showing

are

50.

154,

142,

the
148,

156 and 158

Additionally,

the

spray

origins(i.e.,

thealso

shown.

For

this

exemplary embodiment, the target lift distance 146 is set atwo 2010/126849

PCT/US2010/032472

26
0.9 mm above the seated surface of outwardly opening valves
86.
In addition to theoutside diameters
5(OD)

target locations,the maximumof heads 109 and stems 106 of XovrE

valves 86 are shown relative to their positions with respect
to expansion cylinder 68.
and

134

of

Additionally, the centerlines 132

spray pat terns

12 8

and

13 0,

respectively,

shown extending from the injector tip centers 124
injector spray origins)10

OD targets 142,

148,

are

(i.e., theand passing through their associated150 and 152 and firedeck targets 144,

15 4, 15 6 and 15 8 .
In this coordinate system, the plane of Z=O is thelocation of the
FIG.
15

13).

firedeck

Accordingly,(or flameface)

140

(best

the firedeck targets 144,

seen

in

154,

156

and 158 all have a Z coordinate of zero.
Also for this embodiment, when the XovrE valves 86
are seated,
above

20

the

the maximum ODs of heads 109 are located 2.6 mm
firedeck

140.

As

such,

when

the maximum OD ofhead 109 is raised the target lift distance of 0.9 mm,

themaximum ODs are located 3.5 mm above the firedeck 140.

Thus

the OD targets 142, 148, 150 and 152 all have a Z coordinateof 3.5 mm.
Note that OD target 148 does not fall directly on

25

the perimeter of its associated head 10 9.

This is because

of

end

geometric

obstructions

in

the

enclosing that particular head.

helicalAccordingly,

section102

the centerline

132 had to be pivoted away from the cooler wall surface ofhelical end section 102 and closer to the hotter stem 106.
Technically30

intersects

this

means

that

the

projected

the maximum OD of head 109 atacenterline

132

point

is

that

slightly less than the desired target lift distance of 0.9
mm.

However,the sacrifice in target lift distance 146 iswo 2010/126849

PCT/US2010/032472

27

small and well within the preferred range of between 10 to60 percent of maximum lift of valve 86.
Referring to FIGS.

16-21,

the fuel delivery event

per degrees of crank angle rotation is shown in detail.
5

number in the top right of each figure
locationoftheexpansion piston

74

dead center of the expansion piston 74
The

injectors

90

The

is the crank angle

in degrees

after

top

outsidesof(ATDCe) .

are mounted on thethe helical end sections 102, but are targeted so the spray10

is carried by the air flow across and around the helical end
sections 102 towards the insides of the helical end sections
102.

As such, the air-fuel mixtures mostly exit through the

XovrE valve 86 openings towards the center of the expandercylinder 68 and are carried across the cylinder 68.
15

Referring to FIG. 16,

at -14.5 degrees ATDCe,

injection event has not yet begun.

Additionally,

thethe XovrE

valves 86 are still in their seated position.
Referring to FIG. 17,

at -10.5 degrees ATDCe,theinjection event has begun prior to XovrE valve 86 opening,
20

so that there is time for the fuel sprays 128, 130 to travel
acrossthehelicalend

sections

102

beforethevalvesopen.

Although the injection event typically starts

86(i.e.,

the start of fuel injection into the crossover passages 78)
before
25

the

XovrE

valve

86

opens,

thereareoperatingconditions wherein the injection event may start after the
XovrE valves 86 begin to open.
Referring to FIG.
XovrE

valves86 have18,

at -6.5 degrees ATDCe,

lifted enough

so

that

a

the

substantial

amount of air flow has been established and is beginning to30

affect the trajectory of the sprays 128 and 130.
sprays128

and 130

valve stems 106.

are

still

The twosubstantially straddling thewo 2010/126849

PCT/US2010/032472

28
Referring to FIG.

19,

at -2.5 degrees ATDCe,thetwo sprays 128 and 130 have reached almost fully across thehelical end sections 102 and are still straddling the stems
10 6.
5

However,

there is a fair amount of distortion in the

trajectory of the sprays 128 and 130 as they are being swept
up into the air flow swirling around the helical end section
102.
Referring to FIG. 20, at +1.5 degrees ATDCe, spraypattern 128 on the left injector is being pulled by the air

10

flow to the point where it is just crossing its associatedvalve stem 106.

The spray pattern 128 on the right injector

has been pulled fully across its associated stem 106 and is
beginning to merge with its associated spray pattern 130.
Referring to FIG.
15

21,

at +5. 5 degrees ATDCe,thesprays 128 and 130 from both injectors 90 have been pulledby the swirling air flow to the far edge of the helical end
sections 102,

and have merged together.

The combined fuelsprays 128 and 130 are now exiting through the XovrE valve
86 openings towards the center of the expander cylinder 68
20

and are being carried across the cylinder 68.
The injection events end prior to XovrE valve 86
closing,

so that there is time for the remaining air flow

through the XovrE valves 86 to carry out the majority of theinjected fuel.
25

Typically the duration of the ejection event

is 45 degrees of crank angle or less, preferably 40 degrees
of crank angle or less,and more preferably 35 degrees of

crank

This

angle

or

less.

possibility for fuel

also

helps

to

minimizetheto partially combust in the crossover

passages 78.
30

Althoughreferencetotheinventionhas

specific embodiments,

it

been

described

byshould be understoodthat numerous changes may be made within the spirit and scopeoftheinventive

concepts

described.

Accordingly,itiswo 2010/126849

PCT/US2010/032472

29intended that the invention not be limited to the describedembodiments,

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

wo 2010/126849

PCT/US2010/032472

30

CLAIMS

What is claimed is:
1.
5

An engine comprising:a crankshaft rotatable about a crankshaft axis;
anexpansion

slidablyreceived

withinanconnected

to

the
to

expansion

cylinderandoperatively

crankshaft

such

the

expansion

reciprocate
10pistonthat

throughanexpansion

pistonisoperablestrokeandanexhauststroke during a single rotation of the crankshaft;a crossover passage including walls,
passageconnectingasourceofhighthe crossoverpressure

gas

to

the

expansion cylinder;a15

crossovercontrol

fluid

and

expansion

theexpansioncommunication(XovrE)

betweencylinder,

the

valve

the

XovrE

operablecrossover
valve

to

passageincludingavalve head and a valve stem extending from the valve head;
and
a
20

fuel

injector operable toinjectfuelinto thecrossover passage;
the
holes

fuel

disposedlninjector including a plurality of spraya

nozzle

end

of

the

fuel

injector

andaimed at an at least one target at which fuel emitting from
the
25

spray

holes

is

directed

to

form

at

least

one

spray

pattern;wherein the at least one target is located above aseatedposition

of

the

XovrE

valve

head

and

betweenthewalls of the crossover passage and the XovrE valve stem.
2.
30

holes

The

are aimed atengine

of

claim

1,

wherein

the

spray

a plurality of spray targets

toform aplurality of spray patterns,

the targets

the

the

spray

valve.

patterns

straddle

valve

located such that
stem

of

the

XovrE

wo 2010/126849

PCT/US2010/032472

31
3.

The

engine

of

claim

1,

whereinhole has a centerline extending therethrough,
of

spray

holes

being

centerlines pass5

orientedthrough the

each

spray

the plurality

such

that

the

least

one

target at which

at

spray

hole

the spray holes are aimed.
4.

The engine of claim 3,

wherein one of the atleast one target is an outside diameter target located at apoint on the centerline of one spray hole of the pluralityof spray holes at which said centerline intersects a maximum
10

outsidediameter

of

the

XovrE

valve

head

when

the

XovrE

valve is raised a predetermined target lift distance above
its seated position.
5.

lift
15

distanceThe

engineiswithin

of
a

claim

range

wherein

4,

the

of

10

to

60

percent

of

to

40

percentofmaximum XovrE

valve

lift,

preferably

15

maximum

valve

lift,

and

preferably

XovrE

target

more

20

to

30

percent of maximum XovrE valve lift.
6.

The engine of claim 3, wherein the spray hole

centerlines are substantially independently oriented.
20

7.

The engine of claim 1, wherein the number ofspray patterns equals the number of spray targets.
8.

The engine of claim 1,

wherein the crossover

passage is a helical crossover passage including a helical25

end section disposed over the XovrE valve,

and wherein the

at

the

least

one

target

9.

The

is

locatedwithinhelicalend

section.

end

sectionenginespirals

of

in

claim
one

wherein

8,

of

a

claim

1,

the

helicalclockwiseoracounterclockwise direction.
30

10.

The

engineofvalve is an outwardly opening valve.

wherein

the

XovrE

wo 2010/126849

PCT/US2010/032472

32

11.

The engine of claim 1, wherein:

the source of high pressure gas is a compression
cylinderincludingtherein,5

theacompression

compression

pistoncylinderslidably
being

received

operatively

connected to the crankshaft such that the compression piston
isoperable to reciprocate through an intake stroke and acompression

strokeduringsinglearotationofthecrankshaft; andthe crossover passage interconnects the expansion
10

and compression cylinders.
12.

An engine comprising:a crankshaft rotatable about a crankshaft axis;
an15

expansion

pistonslidably

expansion

cylinderandoperatively

crankshaft

such

the

expansion

reciprocate

thatthroughanexpansion

received withinanconnected

to

the
to

pistonisoperablestrokeandanexhauststroke during a single rotation of the crankshaft;acrossover passage

connecting asourceof highpressure gas to the expansion cylinder;
20

acrossovercontrol

fluid

and

expansion

theexpansion(XovrE)

communication between
cylinder,

the

the

XovrE

valve

operablecrossover
valve

to

passageincludingavalve stem; anda fuel25

injector operable to inject fuelinto thecrossover passage;
the fuelholes

injector including a plurality of spray

disposed in a

nozzle end of thefuelinjector,thespray holes being aimed at two or more targets at which fuelemitting from the spray holes is directed to form at least30

two fuel sprays;
wherein the at least two fuel sprays straddle thevalve stem of the XovrE valve.

wo 2010/126849

PCT/US2010/032472

33
The

13.

engineofclaim 12,

wherein eachhole has a centerline extending therethrough,
of

spray

holes

being

oriented

such

that

spray

the plurality

each

spray

hole

centerline passes through one said target at which fuel5

isdirected.
The

14.

centerlinesofengine

of

spray

holes

formingonetargetthatthepattern are oriented at

a

claim

wherein

the

said

spray

distinctfrom a13,

istarget at which the centerlines of the spray holes forming
10

another said spray pattern are oriented.
15.

The engine of claim 13, wherein:

the XovrE valve includes a valve head disposed at
an end of the valve stem, andone of the targets is an outside diameter target
15

located at a point on the centerline of at least one said
spray holeoutsideatwhichdiameter

of

said
the

centerline
XovrE

intersects

a

head

the

valve

when

maximum
XovrE

valve is raised a predetermined target lift distance above
its seated position.
16.

The

engineofdistanceiswithin

a

20

lift

claim 15,
range

of

whereinto60

percent

of

to

40

percent

of

to

30

valve

lift,

preferably 15

maximum

valve

lift,

and

more

target10

maximum XovrE
XovrE

the

preferably

20

percent of maximum XovrE valve lift.
25

17.

The engine of claim 12, wherein the crossover

passage is a helical crossover passage including a helicalend section disposed over the XovrE valve,

and wherein the

two

the

or

more

targetsarelocatedwithinhelicalend

section.
30

18.

end

sectionThe engine of claim 17,
spiralsincounterclockwise direction.

one

of

wherein the helicalaclockwiseorawo 2010/126849

PCT/US2010/032472

34

19.

The

engine

of

claim

12,

wherein

the

XovrE

valve is an outwardly opening valve.
20.

The engine of claim 12, wherein:

the source of high pressure gas is a compression
5cylinderincludingtherein,theacompression

compression

pistoncylinderslidably
being

received

operatively

connected to the crankshaft such that the compression piston
isoperable to reciprocate through an intake stroke and acompression
10

strokeduringasinglerotationofthecrankshaft; andthe crossover passage interconnects the expansion
and compression cylinders.
21.

A method of injecting fuel in an engine; theengine including a crankshaft rotatable about a crankshaft
15

axis;

an

expansion

pistonslidably

expansion

cylinderandoperatively

crankshaft

such

the

expansion

reciprocate
stroke20

throughduringaan

expansion

singlerotation

withinconnected

the

to

the
to

pistonisoperablestroke

and

an

of

the

exhaustcrankshaft;acrossover passage including walls and connecting a source ofhigh pressure
expansiongas(XovrE)crossover

to

the

valve

passagecommunication
25

that

received

disposed atandbetweenexpansion cylinder,

expansion

cylinder;aan

end ofoperablethecrossoveroutlettocrossovercontrolpassage

and

the

fluid
the

the XovrE valve including a valve head

and a valve stem extending from the valve head;

and a fuelinjector operable to inject fuel into the crossover passage;
the

fuel

injector

includingaplurality

disposed in a nozzle end of the fuel30

ofinjector;

spray

holes

the method

comprising:aiming each spray hole at one of two targets at
which fuel emitting from the spray holes is directed to form
two spray pat terns,

the two targets being located above awo 2010/126849

PCT/US2010/032472

35
seated position of the XovrE valve head and between walls of
the crossover passage and the XovrE valve stem such that thespray patterns straddle the XovrE valve stem;
beginning
5

toinject

fuel

from

the

fuel

injector

towards the outlet end of the crossover passage;
opening the XovrE valve; andendinginjection

of

fuel

prior

to

closing

theopened XovrE valve.
22.
10

The

method

of

claim

21,

whereinfuelinjection is begun before opening the XovrE valve.
2 3.

The

method

of

claim

21,

whereinfuelinjection is begun after opening the XovrE valve.
24.

The method of claim 21,

including the

steps

of:
15

establishing air

flowfrom thecrossover passage

to the expansion cylinder through the open XovrE valve;
sweeping the two spray patterns into the air flowsuch that one said spray pattern is pulled over and acrossthe XovrE valve stem and is merged with the other said spray
20

pattern to generally form a single combined spray.
25.

The

methodofclaim 24,including

the

step

of:
pulling the combined spray towards an edge of theoutlet
25

end

of

the

crossoverpassagewherebythe

combinedspray exits the crossover passage through the XovrE valve.
2 6.
valve

is

The

openedmethodofoutwardly

claim

21,

relative

whereinthetoexpansion

the

XovrE

cylinder.
27.
30

The method of claim 21, wherein a duration of

an injection event from the beginning of fuelinjection to

the ending of fuel injection is approximately 45 degrees of
crank angle or less, preferably 40 degrees of crank angle or
less, and more preferably 35 degrees of crank angle or less.

wo 2010/126849

1114

FIG. 1
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Figure 19

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88

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88
SUBSTITUTE SHEET (RU LE 26)

INTERNATIONAL SEARCH REPORTInternational application No.
PCT/US 10/32472

A.

CLASSIFICATION OF SUBJECT MATTER

IPC(8}- F02B 75/20 (201 0.01)
USPC- 123/59.1
According to International Patent Classification (I PC) or to both national classification and IPC
B.

FIELDS SEARCHED

Minimum documentation searched (classification system followed by classification symbols)
USPC 123159.1

Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched
USPC - 12311 R,52.1 ,53.1 ,53.2,58.9,59.1

Electronic data base consulted during the international search (name of data base and, where practicable, search terms used)
USPTO PatFT, AppFT; PubWEST; Google Scholar. Terms - cross, over, engine, motor, internal, combustion, valve, cylinder, powerplant,
inject$, fuel, nozzle, spray, target, pattern, cycle, split, passage, duct, pipe, channel, compression, expansion, piston, stem, axis, hole,slit, slot, orifice, opening, gap, mixture, droplet, vapor, cone, tip, gasolc.

DOCUMENTS CONSIDERED TO BE RELEVANT

Category*

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

Relevant to claim No.

y

US 2009/0038Sg9 A1 (Tussing, et al). 12 February 2009 (12.02.2009). Para [0005]-[0008),[0011), [0018)-[0019), [0024), [0046]-[0047], [0050], [0052]-[0053], [0055]; Fig. 4-5, 8.

1-27

y

US 2005/0235961 A1 (Kayama, et al). 27 October 2005 (27.10.2005). Para [0010), [0014][0016], [0091), [0093], [0101], [0106)-[0107].

1-27

y

US 4,186,561 A (Wishart). 5 Feburary 1980 (05.02.1 g8o). col 12, In 47 -56; Fig. 20.

4-5, 15-16

yUS 2005/0268609 A1 (Branyon, et al). 8 December 2005 (08.12.2005). Para [0155], [0264).

27

D
•

"A"
"E"
"L"

"0"
"P"

D

Further documents are listed in the continuation of Box C.
Special categories of cited documents:
document defining the general state of the art which is not considered
to be of particular relevanceearlier application or patent but published on or after the international
filing datedocument which may throw doubts on priority claim(s) or which iscited to establish the publication date of another citation or otherspecial reason (as specified)
document referring to an oral disclosure, use, exhibition or othermeans
document published prior to the international filing date but later thanthe priority date claimed

Date of the actual completion of the international search
18 June 2010 (18.06.201 0)
Name and mailing address of the ISA/US
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)

later document published after the international filing date o1eriority
date and not in conflict with the ap~lication but cited to un erstandthe principle or theory underlying t e invention"X" document of particular relevance; the claimed invention cannot be
considered novel or cannot be considered to involve an inventive
step when the document is taken alone"T'"Y" document of particular relevance; the claimed invention cannot be

considered to involve an inventive step when the document iscombined with one or more other such documents, such combination
being obvious to a person skilled in the art"&" document member of the same patent family

Date of mailing of the international search report

01 JUL 2010
Authorized officer:
Lee W. YoungPCT Helpdesk: 571-272-4300
PCT OSP: 571-272-7774