CA1206102A - Two cycle internal combustion engine - Google Patents
Two cycle internal combustion engineInfo
- Publication number
- CA1206102A CA1206102A CA000429236A CA429236A CA1206102A CA 1206102 A CA1206102 A CA 1206102A CA 000429236 A CA000429236 A CA 000429236A CA 429236 A CA429236 A CA 429236A CA 1206102 A CA1206102 A CA 1206102A
- Authority
- CA
- Canada
- Prior art keywords
- piston
- exhaust port
- wrist pin
- oil
- pin bosses
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B25/00—Engines characterised by using fresh charge for scavenging cylinders
- F02B25/02—Engines characterised by using fresh charge for scavenging cylinders using unidirectional scavenging
- F02B25/04—Engines having ports both in cylinder head and in cylinder wall near bottom of piston stroke
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B29/00—Engines characterised by provision for charging or scavenging not provided for in groups F02B25/00, F02B27/00 or F02B33/00 - F02B39/00; Details thereof
- F02B29/06—After-charging, i.e. supplementary charging after scavenging
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B33/00—Engines characterised by provision of pumps for charging or scavenging
- F02B33/32—Engines with pumps other than of reciprocating-piston type
- F02B33/34—Engines with pumps other than of reciprocating-piston type with rotary pumps
- F02B33/36—Engines with pumps other than of reciprocating-piston type with rotary pumps of positive-displacement type
- F02B33/38—Engines with pumps other than of reciprocating-piston type with rotary pumps of positive-displacement type of Roots type
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
- F02B37/04—Engines with exhaust drive and other drive of pumps, e.g. with exhaust-driven pump and mechanically-driven second pump
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
- F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
- F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Lubrication Of Internal Combustion Engines (AREA)
Abstract
HIGH TORQUE TWO-STROKE DIESEL ENGINE
ABSTRACT OF THE DISCLOSURE
A two-stroke engine includes an intake-and-scavenge valve in the cylinder head together with a fuel injection system, a recirculating type pressure lubricating system, and a blower or turbo charger assisting in charging the cylinder with air and also assisting in scavenging the exhaust gases.
The piston head is domed with one side curving downwardly to-wards the exhaust port formed through the wall of the cylin-der above the bottom dead centre position of the piston head.
The exhaust port slopes outwardly and downwardly following generally the slope of the piston to facilitate the flow of exhaust gases therethrough assisted by the scavenging air entering through the inlet-and-scavenger valve. The valve is operated by a cam mounted on a cam shaft upon the cylin-der head which in turn is operatively connected to the crank shaft. The width of the cam lobe is such that the opening, closing and duration of opening of the valve is controlled with the valve being opened approximately 140° and with the piston controlling the opening of the exhaust port through approximately 130° so that there is approximately a 5° over-lap at either end of the exhaust port opening. It should be noted that the oil scraper ring remains below the exhaust port at all times to prevent lubricating oil from escaping through the exhaust port.
ABSTRACT OF THE DISCLOSURE
A two-stroke engine includes an intake-and-scavenge valve in the cylinder head together with a fuel injection system, a recirculating type pressure lubricating system, and a blower or turbo charger assisting in charging the cylinder with air and also assisting in scavenging the exhaust gases.
The piston head is domed with one side curving downwardly to-wards the exhaust port formed through the wall of the cylin-der above the bottom dead centre position of the piston head.
The exhaust port slopes outwardly and downwardly following generally the slope of the piston to facilitate the flow of exhaust gases therethrough assisted by the scavenging air entering through the inlet-and-scavenger valve. The valve is operated by a cam mounted on a cam shaft upon the cylin-der head which in turn is operatively connected to the crank shaft. The width of the cam lobe is such that the opening, closing and duration of opening of the valve is controlled with the valve being opened approximately 140° and with the piston controlling the opening of the exhaust port through approximately 130° so that there is approximately a 5° over-lap at either end of the exhaust port opening. It should be noted that the oil scraper ring remains below the exhaust port at all times to prevent lubricating oil from escaping through the exhaust port.
Description
~%~6~%
TWO CYCLE INTERNAL COMBUSTION EN&INE
BA~KGROUND OF THE INVENTION
This invention relates to a new and improved method of operating a two-stroke or two cycle high torque and high speed gas or diesel ~ueled multi-cylinder internal combustion engine utilizing an air blower or turbo charger combination connected in series, and having a new and improved design of the internal moving parts, more specifically to the design of the scavenging valves which are opened and closed by the re-latively wide area of cam lobes of a cam shaft and related mechanisms all assembled in the cylinder head. Also of impor-tance is the piston assembly having a novel feature of design.
A recirculating type pressure lubrication system is used to lubricate all the vital and critical moving parts, making this invention an efficient device. The design and location also of the exhaust ports in each of the cylinders provides the~most efficient operatlon of this machine.
SUMMARY OF THE INVENTION
.., . . , . . _ :
~ It is an object of this invention therefore to dlsclose its design, ltS novel~featuresj its advant~ages, ltS
efficiency and method of operation.
Among the objects of this invention is how to eli-minate the many disadvantages, l~imitations,~difflculties and :: ~ :
:
, 6~
inefficient operations of most two-stroke engines specially when pressure lubrication is used.
Another object of this invention is to disclose and provide a device of the character herewithin described in which a new and improved design of the scavenging valves which are opened and closed by cam lobes of special design having relatively wide area of contact for longer duration of valve opening period. The valves and related mechanisms are assembled and installed in the cylindex head.
Still another object of this invention is to dis-close and provid~ a device of the character herewithin des-cribed in which a new and improved design of the piston as-sembly, having novel features that reduces and controls pressure lubrication problems, Still another object of this invention i9 to dis-close a new and improved design of the pi~ton assembly, the design of the scavenging valves and related mechanisms and the design and location of the exhaust port openings in each ~cylinder an~d the application of an alr blower which together leads to ~his~relatLvely cleaner exhaust~gas emisslon cha-racteristic.
Still another object of this invèntion~is to pro-vide an engine capable o~f produci~ng high~torque and high~re-volution per minute because o less~mo~ing parts and compact . ~2~ 2 assembly.
Still another object of this invention is to provide a device of the character herewithin described which may include the design of the air blower assembly having a scoop~type impeller and a compressor rotor that are bolted together to a common shaft supported with ball bearings that can be driven by means of a gear or by a belt pulley.
Still another object of this invention is to provide a device of the character herewithin described which is compact in design, economical in manufacture and otherwise well suited to the purpose for which it is de-signed~
` In accordance with the inven~ion there is provi-ded a two-stroke supercharged multi-cylinder internal com-bustion engine, with inline or V-type configuration and~in-~
cluding a pressure lubrication~system; compriaing in combi-nation a cylinder block having~cy1inder bores formed there-in, a cylinder:head on the~upper end of the oyl1ndrica1 bores : 20 and closing same and defining~a combustion chamber~at:the up-per e~nd of each cylindrical~ bore, a~p1ston assemb1y in each of said bores includ1ng a piston~havlng a domed~head and connecting rod operatively connected~o said piston~for re-ciprocating same between~top dead~centre~and bottom~dead cen-: ~
.. :: : :
tre, a crankshaft mounted for rotation at the base of said block, said connecting rods being operatively connected to said crankshaft and an oil pan enclosing the lower end of the cylinder bores and said crankshaft, said cylinder head including a cam shaft mounted for rotation thereon and be-ing operatively connected to said crankshaft, at least one inlet-and scavenger valve mounked on said cylinder head and being operatively connected with said combustion chamber of each of said cylindrical bores, a rocker arm operatively mounted on said cylinder head and operatively engaging said inlet-and-scavenger valve by one end thereof, a cam lobe for eaoh xocker arm formed on said cam shaft operatively connected with the other end of said rocker arm, said cam lobes having a xelatively wide axea of contact with said : rocker arm to control the openingj closing~and duration of:
opening of said inlet-and-~cavenger~valve and exhaust port located in the lower side of~the cylinder walls of the cy~
llnder bores inclining downwardly and outwardly through the~
: :~ cyllnder:walls and being covered~and~uncovered b~ the~recl-procating piston passing thereby. :
With the for~goin~in view,~ and other:advantages as will become apparent to those~ killed~;in~the art~to which this:lnvention relates as this~specification prooeeds~, the invention is herein des~cribed~by:referen~e to the àcco~pany-~
::~20~
ing drawin~s forming a part hereof, which includes a desorip-tion of the best msde known to the applicant and of ~he pre-ferred typical embodiment of the principles of the present invention, in which:
DESCRIPTI~N OF THE DRAWINGS
Figure 1 is a schematic partially sectioned side elevation of one cylinder and a piston assembly showing the piston position in the latter part of the power stroke with the scavenging valv~ or intake valve already partly opened.
Figure 2 is a view similar to Figure 1 but showing the piston position at bottom dead centre with the intake valve fully opened.
Figure 3 is a view similar to Figure 1 but showing the exhaust port covered by the piston at the beginning of the compression stroke with the intake valve still partly opened.
~igure 4 is a view similar to Fiyure 1 but showing the piston pssition at top dead centre of its compression stroke.
2Q Figure 5 is a fragmentary cross sectional view of the piston and connectiny rod assembly ~ se.
Figure 6 is a schematlc side elevation partially sectioned showing a turbo charger connected to the engine.
Figure 7 is~a view similar to Figure 6 but showing : ~ :
-J
~L2~
a V-type configuxation.
Figure 8 is a fragmentary cross sectional view of the preferred air blower construction.
Figure 9 is a view from the left hand side of Figure 8.
Figure 10 is an example of the valve and port dia-gram of the engine.
In the drawings like characters of r~ference indi-ca~e corresponding parts in the diff~rent figuxes.
DETAILED DESCRIPTION
.... . .. _ Proceeding therefore to describe the invention in detail, reference should first be made to Figures 1 to 4 in which reference character 10 illustrates generally a cylin-der including a cylinder wall ll, wa~er cooling passages 12 formed ther~ln and a cylinder head assem~ly 13 secured~to the upper side of the cylinder by conventional means tnot ; illustrat~d).
A valve ~asing 14 surmounts the;cylinder head and is once again connected by conventlona~l~means;~not shown~
A pis~on assembly is xecipro~al within said~`cylin-der, said piston assembly being gen0rally~designa~ed by re-ference character l5 and including a piston collectively de-signated 16 and a connecting~rod oollectively designated 17, details of which will hereinaftex be described~
: ~ :
.
: : :
~2~
. 7 An exhaust port 18 is formed through the wall of the cylinder 11 on one side thereof, said exhaust port pre-ferably being of rectangular configuration and inclining downwardly and outwardly through the wall as clearly shown in Figures 1 to 4.
An exhaust conduit 19 leading to an exhaust mani-fold 20 (see Figure 6~ is secur~d to the exhaust port on the outer side thereof by means of flange 21 and bolts 22 and this exhaust conduit 19 extends outwardly and downward-ly at an inclined angle similar to the inclined angle of the exhaust port through the cylinder wall 11 to facilitate the exit of exhaust gases as will hereinafter be described~
At least one and preferably two or more air intakeand scavenging valves 23 are provided within the cylinder head 13 normally seated on valve seats 24 and being retain-ed therein by means of valve springs 25 on the upper ends 26 of the valve stems which engage through ~alve guides 27 : within the head 13 in a conventional manner.
These valves are preferably operated by an over-
TWO CYCLE INTERNAL COMBUSTION EN&INE
BA~KGROUND OF THE INVENTION
This invention relates to a new and improved method of operating a two-stroke or two cycle high torque and high speed gas or diesel ~ueled multi-cylinder internal combustion engine utilizing an air blower or turbo charger combination connected in series, and having a new and improved design of the internal moving parts, more specifically to the design of the scavenging valves which are opened and closed by the re-latively wide area of cam lobes of a cam shaft and related mechanisms all assembled in the cylinder head. Also of impor-tance is the piston assembly having a novel feature of design.
A recirculating type pressure lubrication system is used to lubricate all the vital and critical moving parts, making this invention an efficient device. The design and location also of the exhaust ports in each of the cylinders provides the~most efficient operatlon of this machine.
SUMMARY OF THE INVENTION
.., . . , . . _ :
~ It is an object of this invention therefore to dlsclose its design, ltS novel~featuresj its advant~ages, ltS
efficiency and method of operation.
Among the objects of this invention is how to eli-minate the many disadvantages, l~imitations,~difflculties and :: ~ :
:
, 6~
inefficient operations of most two-stroke engines specially when pressure lubrication is used.
Another object of this invention is to disclose and provide a device of the character herewithin described in which a new and improved design of the scavenging valves which are opened and closed by cam lobes of special design having relatively wide area of contact for longer duration of valve opening period. The valves and related mechanisms are assembled and installed in the cylindex head.
Still another object of this invention is to dis-close and provid~ a device of the character herewithin des-cribed in which a new and improved design of the piston as-sembly, having novel features that reduces and controls pressure lubrication problems, Still another object of this invention i9 to dis-close a new and improved design of the pi~ton assembly, the design of the scavenging valves and related mechanisms and the design and location of the exhaust port openings in each ~cylinder an~d the application of an alr blower which together leads to ~his~relatLvely cleaner exhaust~gas emisslon cha-racteristic.
Still another object of this invèntion~is to pro-vide an engine capable o~f produci~ng high~torque and high~re-volution per minute because o less~mo~ing parts and compact . ~2~ 2 assembly.
Still another object of this invention is to provide a device of the character herewithin described which may include the design of the air blower assembly having a scoop~type impeller and a compressor rotor that are bolted together to a common shaft supported with ball bearings that can be driven by means of a gear or by a belt pulley.
Still another object of this invention is to provide a device of the character herewithin described which is compact in design, economical in manufacture and otherwise well suited to the purpose for which it is de-signed~
` In accordance with the inven~ion there is provi-ded a two-stroke supercharged multi-cylinder internal com-bustion engine, with inline or V-type configuration and~in-~
cluding a pressure lubrication~system; compriaing in combi-nation a cylinder block having~cy1inder bores formed there-in, a cylinder:head on the~upper end of the oyl1ndrica1 bores : 20 and closing same and defining~a combustion chamber~at:the up-per e~nd of each cylindrical~ bore, a~p1ston assemb1y in each of said bores includ1ng a piston~havlng a domed~head and connecting rod operatively connected~o said piston~for re-ciprocating same between~top dead~centre~and bottom~dead cen-: ~
.. :: : :
tre, a crankshaft mounted for rotation at the base of said block, said connecting rods being operatively connected to said crankshaft and an oil pan enclosing the lower end of the cylinder bores and said crankshaft, said cylinder head including a cam shaft mounted for rotation thereon and be-ing operatively connected to said crankshaft, at least one inlet-and scavenger valve mounked on said cylinder head and being operatively connected with said combustion chamber of each of said cylindrical bores, a rocker arm operatively mounted on said cylinder head and operatively engaging said inlet-and-scavenger valve by one end thereof, a cam lobe for eaoh xocker arm formed on said cam shaft operatively connected with the other end of said rocker arm, said cam lobes having a xelatively wide axea of contact with said : rocker arm to control the openingj closing~and duration of:
opening of said inlet-and-~cavenger~valve and exhaust port located in the lower side of~the cylinder walls of the cy~
llnder bores inclining downwardly and outwardly through the~
: :~ cyllnder:walls and being covered~and~uncovered b~ the~recl-procating piston passing thereby. :
With the for~goin~in view,~ and other:advantages as will become apparent to those~ killed~;in~the art~to which this:lnvention relates as this~specification prooeeds~, the invention is herein des~cribed~by:referen~e to the àcco~pany-~
::~20~
ing drawin~s forming a part hereof, which includes a desorip-tion of the best msde known to the applicant and of ~he pre-ferred typical embodiment of the principles of the present invention, in which:
DESCRIPTI~N OF THE DRAWINGS
Figure 1 is a schematic partially sectioned side elevation of one cylinder and a piston assembly showing the piston position in the latter part of the power stroke with the scavenging valv~ or intake valve already partly opened.
Figure 2 is a view similar to Figure 1 but showing the piston position at bottom dead centre with the intake valve fully opened.
Figure 3 is a view similar to Figure 1 but showing the exhaust port covered by the piston at the beginning of the compression stroke with the intake valve still partly opened.
~igure 4 is a view similar to Fiyure 1 but showing the piston pssition at top dead centre of its compression stroke.
2Q Figure 5 is a fragmentary cross sectional view of the piston and connectiny rod assembly ~ se.
Figure 6 is a schematlc side elevation partially sectioned showing a turbo charger connected to the engine.
Figure 7 is~a view similar to Figure 6 but showing : ~ :
-J
~L2~
a V-type configuxation.
Figure 8 is a fragmentary cross sectional view of the preferred air blower construction.
Figure 9 is a view from the left hand side of Figure 8.
Figure 10 is an example of the valve and port dia-gram of the engine.
In the drawings like characters of r~ference indi-ca~e corresponding parts in the diff~rent figuxes.
DETAILED DESCRIPTION
.... . .. _ Proceeding therefore to describe the invention in detail, reference should first be made to Figures 1 to 4 in which reference character 10 illustrates generally a cylin-der including a cylinder wall ll, wa~er cooling passages 12 formed ther~ln and a cylinder head assem~ly 13 secured~to the upper side of the cylinder by conventional means tnot ; illustrat~d).
A valve ~asing 14 surmounts the;cylinder head and is once again connected by conventlona~l~means;~not shown~
A pis~on assembly is xecipro~al within said~`cylin-der, said piston assembly being gen0rally~designa~ed by re-ference character l5 and including a piston collectively de-signated 16 and a connecting~rod oollectively designated 17, details of which will hereinaftex be described~
: ~ :
.
: : :
~2~
. 7 An exhaust port 18 is formed through the wall of the cylinder 11 on one side thereof, said exhaust port pre-ferably being of rectangular configuration and inclining downwardly and outwardly through the wall as clearly shown in Figures 1 to 4.
An exhaust conduit 19 leading to an exhaust mani-fold 20 (see Figure 6~ is secur~d to the exhaust port on the outer side thereof by means of flange 21 and bolts 22 and this exhaust conduit 19 extends outwardly and downward-ly at an inclined angle similar to the inclined angle of the exhaust port through the cylinder wall 11 to facilitate the exit of exhaust gases as will hereinafter be described~
At least one and preferably two or more air intakeand scavenging valves 23 are provided within the cylinder head 13 normally seated on valve seats 24 and being retain-ed therein by means of valve springs 25 on the upper ends 26 of the valve stems which engage through ~alve guides 27 : within the head 13 in a conventional manner.
These valves are preferably operated by an over-
2~ head cam shaft 28 supported for rotation in a csnventional manner (not illustrated) and being opera iveIy connected to the crankshaft (not illustrated~ which is also conventional.
Howev~r, the cam lobes 29 of the cam shaft areshaped with a relatively wide contact area:30A to control ::
the duration of the opening of the air intake valves 33 and also the time that they are opened and closed.
The cam lobes 29 engage rocker arms 30 pivoted by one end thereof to rocker arm bearings 31 and engaging the upper ends 26 of the valve stems by the other ends 32A in a conventional manner.
In Figures 1 to 4, an air blower assembly collec-tively designated 32 is provided and is operati~ely connec-ted to the engine in a conventional manner ts supply air un-10der superatmospheric pressure ts the air inlet valve 23 via passages 33 which may be connected to an intake manifold if~
a plurality of pistons and cylinders are utilized.
Details of the preerred embodiment o the air blower assembly are shown in Figures 8 and 9 and com~rises a cylindrical casing 34 within which a fan blade assembIy~
collectively designated 35 is supported for rotation upon ~a shaft 36~supported with bearings 37 and drlven rom ~he~
engine by means of gear~ 38~or gear bel~(not illustrated)~
~either o whlch is operatlvely;connected~to the~cam~shat 20in a conventional manner~ by~means~o~a gear chaln~or~cog~
belt.
The blower~includes;the~aforementioned~combination an~assemb1y 35 with an~outer~se~t;~of~impeller blades 3~9~and an inner set of~ screw~or~compréssor blades 40. Rotation ~f .
` " ~2~
g the fan assembly in the direction of arrow 41, draws airthrough the central intake 42 in the centre o the front wall of the casing, compresses same and ejects it from the discharge end 43 which is operatively connected to the air intake valves 23 as hereinafter described.
Reference should be made to the piston assembly illustrated in detail in Figure 5. The piston is prefer-ably formed from aluminum alloy and includes a piston head 44, a piston head crown 45 and a surrounding cylindrical skirt portion 46.
The piston crown 45 is domed as illustrated by refer2nce character 47 and is convexly curved with ~he side of the crown 48 towards the exhaust port 18 curving down to a point 48 which is lower than ~he junction of the crown to the head on the opposite side as illustrated by reference character 50 50 that the apex 51 of the dome is offset from the vertical centre line of the piston, towards the side 50 which is diametrically opposite to the lower side 49 on the exhaust port side of the cylinder when assembled.
This facilitates the flow of exhaust gases from the combustion chamber 52 assisted by the ~ir entering ~ia the blower a~sembly 32.
, A pair of opposed piston boss~es 53 axe formed with-in the wall of the piston in a conventional manner and a ~: `~ ; : : :
.
` ~2~6~L~2 wrlst.pin 54 bearingly engages these bosses and also bear-ingly engages the wrist pin end 55 of the connecting rod 17.
It is desira~le to seal the outer ends of the boss-es 53 to prevent lubrica~ing oil ~rom bein~ discharged there-through and in this connection a tie rod or pin 56 ex~ends freely through the wrist pin 54 which is hollow, and is se-cured as by brazing to tw~ concave ~eallng end caps 57 , one being situated slightly within each outex end 58 of the wrist pin bosses of the piston as clearly shown.
A pair or more of compression piston rings 59 are seated within the piston ring grooves 60 around the piston adjacent the upper end of the head thereof and an oil scra-per ring 61 is installed within an annular groove 62 adja-cent the base of the skirt o~ the piston with oil return apertures 63 being fsrmed through the skirk at the base of~
the groove in a conventional manner. : ::
O~ importance i~ khe fact that the oil scraper~ ~
: ring always remains below the lower side 18A of the exhaust port:when the piston is in the top dead centre posi~ion as 20 illustrated in Figure 4.
The exhaust port 18 design lS such that lt incli-~
nes downwardly and outwardIy on the~walls of the cylinder:
and ~he attaching èxhaust~conduit is preferably~rectangular in configura~lon and may be provided with one or more verti-:
: :
~ 6~
cal bars 64 to guide the compression rings past the exhaust port and to prevent them catching on the edges of the walls defining the port.
In operation to this point, reference should be made to Figures l to 4.
In Figure l, the piston 15 is approaching the low-er end of the power stroke and the scavenging valve is just beginning to open. In Figure 2~ ~he piston is at the lower end of the power stroke with the exhaust port 18 being un-covered and air passing through the now fully opened scaven-ging or inlet valve, being supplied in sufficient volume by the blower assembly 32, to complete scavenge the exhaust gases through the exhaust port facilitated by the common angle of the piston head crown at this point and downwardly inclining exhaust port 18 and exhaust conduit l9.
In this position, the plston is at the bottom dead centre and in Figure 3 it is commenc:ing to mo oe upwardly on ~: ~ the compre~sion~stroke having covered the:~exhaust port 18 although the scavenging valve is still~slightly open to en-: 20 : ~sure that a full charge o~ air is:~supplied within: he:combus-tion chamber 52.
. The æcavenging or intake valve~23 now closes~as ~: the plston contlnues to move upwardly~on the compression~ :
stroka to the top:dead centre position as shown in;Figurè 4.
.
~Z[)6~
With the piston at this position, it will be noted that the aforementioned oil scraper ring ~1 always remains be-low the lower edge 18A of the exhaust port so that the lu-bricating oil cannot escape through this port.
Within a few degreees of the piston reaching the top dead centre of its travel as shown in Figure 4, an atom-ized spray of fuel is injected via a conventional fuel in-jector assembly 65 which ignites due ~o ~he highly compres-sed air ~etween the crown of domed piston head and the com-bustion chamber of the cylinder head, in a conventional man-ner with the scavenging valve 23 being completely closed at this point. The ignited fuel and highly compressed air mix-ture expands and pushes the moving piston downwardly perform-iny the power or expansion stroke to the posltion shown in Figure 1 and the cycle of operation is repeated again and again.
It is to be noted that the scavenging valves 23 are of relatively large diameter to ensure that the air~sup-plied to cylinders 52 is sufficient to~completely scavenge and charge its cylinders every time the piston reaches the bottom of its stroke.
It is also to be noted~further that the~sc~venging valves 23 are opened and closed at the correct timing~in ~
relatio~ to the piston degrees of~travel.~ In~order to achieve :: : :
: ~:: ::: ~ :: :
., : : .: . . .
~06~
this, cam lobes 29 of the cam shaft 28 have a relatively wide area of contact 30A and is designed to correctly time the duration of opening and closing of its scavenging valves 23 in relation to the piston degrees of travel. The sca-venging valves 23, the rockers 30 and c~m lobes 2g of the cam shaft 28 are mechanically contacting one another and are all assembled upon the cylinder head. The cam shaft 28 is mechanically driven by the cranks~af~ by means of gears and chain or cogged belt in a conventional mannerO
Reference should be made to the novel design of the piston assembly illustrated in detail in Figure 5.
The piston is preferably formed from alumin~n alloy and in-cludes a piston head 44, a piston head crown and a surround-ing cylindrical skirt portion 46.
As discussed previously,` another very important point to be rnoved is the piston assembly shown in a;frag- ;
mentary form as in Figure S, having a novel desLgn features that controls and reduces lubricating~ oil problems;:especial-ly if a pressure lubrication~system is utilized"in a two : 20 cycle engine. The novel design features of~the piston~as-~:
sembly are: the head ~45 is~dome shaped:to facilitate the flow o~ the scavenging exhaust gases, a pair of compression rings 59 and a pair of ~sealing caps:~57~installed ~t~both : ends of the piston bo~sess` For~safety ~f operation these ~zo~
sealing caps 57 are secured by brazing a pin 56 that ex-tends freely through the wrist pin 54 which is hollow.
The sealing caps 57 are installed at each outer end of the piston bosses 58 to prevent any amount of th~ lubri-cating oil from being discharged therethrough.
Another important feature of the piston assembly to be noted is the oil scraper ring 61 which is installed close to the base of the piston skir~ with oil return holes 6 3, the function of which is to prevent any amount of lubri-cating oil from being discharged to the exhaust ports 18 and that said oil scraper 61 always remains below the lower side 18A of the exhaust port when the piston is in the top dead centre position of its stroke.
The exhaust port 18 is located in the side of the cylinder wall adjacent the bottom dead centre position of the piston, the design of which is incllning downwardly and outwaxdly and is covered and ~ncovered by the piston, the design of which is to facilitate the flow of exhaust gases more freely into the atmosphere.
::
As mentioned previously, this invention is suit-able for use with slngle or mu1ti-cylinders~ either inline or V-type configuration being shown schematically in Figu-res 6 and 7 xespectively.
It will also be appreclated that the air blower ~: ~
~2(~6~
assembly 32 can be used with all configurations or alterna-tively, a turbo charger and aix blower combination connect-ed 1n s~ries can be utilized as shown schematically in Figure 7 collectively designated 66.
Final~y, reference should be made to Figure 10 which shows a valve and port diagram.
The width of the cam lobe 30A is such that the in-let and scavenger valve opens approximately 105 to 110 af-ter top dead centre and closes approximately 70 after bot-tom dead centre so that it remains open through approxima-tely 140.
The position of the exhaust port relative to the piston is such that the piston uncovers the exhaust port at approximately 115 after ~op dead centre and covers or closes the exhaust port at approximately 65 after bottom dead centre so that the ~xhaust port remains uncovered through approximately 130o The relationship between the exhaust port opening and the inlet-and-scavenger valve o~ening is such that there is approximately a 5 overlap :: : : :
at either end in which the inlet-and-scavenger valve is open approximately ~ before the exhaust port i~ uncovered and remaina open approximately 5 after~the exhaust port is covered or clo~es. : : :
~ This provides the necessary:control for the open-ing, closing and duration of opening of the inlet-and-sca-venger valve with the pis~on ~nd position of the exhaust port controlling the opening, closing and duration of open-ing o the exhaust port.
Since various modifications can be made in my in~-vention as hereinabove described, and many apparently wide-ly different embodiments of same made within the spirit and scope of the claims without departing frGm such spirit and scope, it is intended that all matter contained in the ac-companying specification shall be interpreted as illustra-tive only and not in a limiting sense.
~ :
:
Howev~r, the cam lobes 29 of the cam shaft areshaped with a relatively wide contact area:30A to control ::
the duration of the opening of the air intake valves 33 and also the time that they are opened and closed.
The cam lobes 29 engage rocker arms 30 pivoted by one end thereof to rocker arm bearings 31 and engaging the upper ends 26 of the valve stems by the other ends 32A in a conventional manner.
In Figures 1 to 4, an air blower assembly collec-tively designated 32 is provided and is operati~ely connec-ted to the engine in a conventional manner ts supply air un-10der superatmospheric pressure ts the air inlet valve 23 via passages 33 which may be connected to an intake manifold if~
a plurality of pistons and cylinders are utilized.
Details of the preerred embodiment o the air blower assembly are shown in Figures 8 and 9 and com~rises a cylindrical casing 34 within which a fan blade assembIy~
collectively designated 35 is supported for rotation upon ~a shaft 36~supported with bearings 37 and drlven rom ~he~
engine by means of gear~ 38~or gear bel~(not illustrated)~
~either o whlch is operatlvely;connected~to the~cam~shat 20in a conventional manner~ by~means~o~a gear chaln~or~cog~
belt.
The blower~includes;the~aforementioned~combination an~assemb1y 35 with an~outer~se~t;~of~impeller blades 3~9~and an inner set of~ screw~or~compréssor blades 40. Rotation ~f .
` " ~2~
g the fan assembly in the direction of arrow 41, draws airthrough the central intake 42 in the centre o the front wall of the casing, compresses same and ejects it from the discharge end 43 which is operatively connected to the air intake valves 23 as hereinafter described.
Reference should be made to the piston assembly illustrated in detail in Figure 5. The piston is prefer-ably formed from aluminum alloy and includes a piston head 44, a piston head crown 45 and a surrounding cylindrical skirt portion 46.
The piston crown 45 is domed as illustrated by refer2nce character 47 and is convexly curved with ~he side of the crown 48 towards the exhaust port 18 curving down to a point 48 which is lower than ~he junction of the crown to the head on the opposite side as illustrated by reference character 50 50 that the apex 51 of the dome is offset from the vertical centre line of the piston, towards the side 50 which is diametrically opposite to the lower side 49 on the exhaust port side of the cylinder when assembled.
This facilitates the flow of exhaust gases from the combustion chamber 52 assisted by the ~ir entering ~ia the blower a~sembly 32.
, A pair of opposed piston boss~es 53 axe formed with-in the wall of the piston in a conventional manner and a ~: `~ ; : : :
.
` ~2~6~L~2 wrlst.pin 54 bearingly engages these bosses and also bear-ingly engages the wrist pin end 55 of the connecting rod 17.
It is desira~le to seal the outer ends of the boss-es 53 to prevent lubrica~ing oil ~rom bein~ discharged there-through and in this connection a tie rod or pin 56 ex~ends freely through the wrist pin 54 which is hollow, and is se-cured as by brazing to tw~ concave ~eallng end caps 57 , one being situated slightly within each outex end 58 of the wrist pin bosses of the piston as clearly shown.
A pair or more of compression piston rings 59 are seated within the piston ring grooves 60 around the piston adjacent the upper end of the head thereof and an oil scra-per ring 61 is installed within an annular groove 62 adja-cent the base of the skirt o~ the piston with oil return apertures 63 being fsrmed through the skirk at the base of~
the groove in a conventional manner. : ::
O~ importance i~ khe fact that the oil scraper~ ~
: ring always remains below the lower side 18A of the exhaust port:when the piston is in the top dead centre posi~ion as 20 illustrated in Figure 4.
The exhaust port 18 design lS such that lt incli-~
nes downwardly and outwardIy on the~walls of the cylinder:
and ~he attaching èxhaust~conduit is preferably~rectangular in configura~lon and may be provided with one or more verti-:
: :
~ 6~
cal bars 64 to guide the compression rings past the exhaust port and to prevent them catching on the edges of the walls defining the port.
In operation to this point, reference should be made to Figures l to 4.
In Figure l, the piston 15 is approaching the low-er end of the power stroke and the scavenging valve is just beginning to open. In Figure 2~ ~he piston is at the lower end of the power stroke with the exhaust port 18 being un-covered and air passing through the now fully opened scaven-ging or inlet valve, being supplied in sufficient volume by the blower assembly 32, to complete scavenge the exhaust gases through the exhaust port facilitated by the common angle of the piston head crown at this point and downwardly inclining exhaust port 18 and exhaust conduit l9.
In this position, the plston is at the bottom dead centre and in Figure 3 it is commenc:ing to mo oe upwardly on ~: ~ the compre~sion~stroke having covered the:~exhaust port 18 although the scavenging valve is still~slightly open to en-: 20 : ~sure that a full charge o~ air is:~supplied within: he:combus-tion chamber 52.
. The æcavenging or intake valve~23 now closes~as ~: the plston contlnues to move upwardly~on the compression~ :
stroka to the top:dead centre position as shown in;Figurè 4.
.
~Z[)6~
With the piston at this position, it will be noted that the aforementioned oil scraper ring ~1 always remains be-low the lower edge 18A of the exhaust port so that the lu-bricating oil cannot escape through this port.
Within a few degreees of the piston reaching the top dead centre of its travel as shown in Figure 4, an atom-ized spray of fuel is injected via a conventional fuel in-jector assembly 65 which ignites due ~o ~he highly compres-sed air ~etween the crown of domed piston head and the com-bustion chamber of the cylinder head, in a conventional man-ner with the scavenging valve 23 being completely closed at this point. The ignited fuel and highly compressed air mix-ture expands and pushes the moving piston downwardly perform-iny the power or expansion stroke to the posltion shown in Figure 1 and the cycle of operation is repeated again and again.
It is to be noted that the scavenging valves 23 are of relatively large diameter to ensure that the air~sup-plied to cylinders 52 is sufficient to~completely scavenge and charge its cylinders every time the piston reaches the bottom of its stroke.
It is also to be noted~further that the~sc~venging valves 23 are opened and closed at the correct timing~in ~
relatio~ to the piston degrees of~travel.~ In~order to achieve :: : :
: ~:: ::: ~ :: :
., : : .: . . .
~06~
this, cam lobes 29 of the cam shaft 28 have a relatively wide area of contact 30A and is designed to correctly time the duration of opening and closing of its scavenging valves 23 in relation to the piston degrees of travel. The sca-venging valves 23, the rockers 30 and c~m lobes 2g of the cam shaft 28 are mechanically contacting one another and are all assembled upon the cylinder head. The cam shaft 28 is mechanically driven by the cranks~af~ by means of gears and chain or cogged belt in a conventional mannerO
Reference should be made to the novel design of the piston assembly illustrated in detail in Figure 5.
The piston is preferably formed from alumin~n alloy and in-cludes a piston head 44, a piston head crown and a surround-ing cylindrical skirt portion 46.
As discussed previously,` another very important point to be rnoved is the piston assembly shown in a;frag- ;
mentary form as in Figure S, having a novel desLgn features that controls and reduces lubricating~ oil problems;:especial-ly if a pressure lubrication~system is utilized"in a two : 20 cycle engine. The novel design features of~the piston~as-~:
sembly are: the head ~45 is~dome shaped:to facilitate the flow o~ the scavenging exhaust gases, a pair of compression rings 59 and a pair of ~sealing caps:~57~installed ~t~both : ends of the piston bo~sess` For~safety ~f operation these ~zo~
sealing caps 57 are secured by brazing a pin 56 that ex-tends freely through the wrist pin 54 which is hollow.
The sealing caps 57 are installed at each outer end of the piston bosses 58 to prevent any amount of th~ lubri-cating oil from being discharged therethrough.
Another important feature of the piston assembly to be noted is the oil scraper ring 61 which is installed close to the base of the piston skir~ with oil return holes 6 3, the function of which is to prevent any amount of lubri-cating oil from being discharged to the exhaust ports 18 and that said oil scraper 61 always remains below the lower side 18A of the exhaust port when the piston is in the top dead centre position of its stroke.
The exhaust port 18 is located in the side of the cylinder wall adjacent the bottom dead centre position of the piston, the design of which is incllning downwardly and outwaxdly and is covered and ~ncovered by the piston, the design of which is to facilitate the flow of exhaust gases more freely into the atmosphere.
::
As mentioned previously, this invention is suit-able for use with slngle or mu1ti-cylinders~ either inline or V-type configuration being shown schematically in Figu-res 6 and 7 xespectively.
It will also be appreclated that the air blower ~: ~
~2(~6~
assembly 32 can be used with all configurations or alterna-tively, a turbo charger and aix blower combination connect-ed 1n s~ries can be utilized as shown schematically in Figure 7 collectively designated 66.
Final~y, reference should be made to Figure 10 which shows a valve and port diagram.
The width of the cam lobe 30A is such that the in-let and scavenger valve opens approximately 105 to 110 af-ter top dead centre and closes approximately 70 after bot-tom dead centre so that it remains open through approxima-tely 140.
The position of the exhaust port relative to the piston is such that the piston uncovers the exhaust port at approximately 115 after ~op dead centre and covers or closes the exhaust port at approximately 65 after bottom dead centre so that the ~xhaust port remains uncovered through approximately 130o The relationship between the exhaust port opening and the inlet-and-scavenger valve o~ening is such that there is approximately a 5 overlap :: : : :
at either end in which the inlet-and-scavenger valve is open approximately ~ before the exhaust port i~ uncovered and remaina open approximately 5 after~the exhaust port is covered or clo~es. : : :
~ This provides the necessary:control for the open-ing, closing and duration of opening of the inlet-and-sca-venger valve with the pis~on ~nd position of the exhaust port controlling the opening, closing and duration of open-ing o the exhaust port.
Since various modifications can be made in my in~-vention as hereinabove described, and many apparently wide-ly different embodiments of same made within the spirit and scope of the claims without departing frGm such spirit and scope, it is intended that all matter contained in the ac-companying specification shall be interpreted as illustra-tive only and not in a limiting sense.
~ :
:
Claims
CLAIMS:
(1) A two-stroke supercharged multi-cylinder in-ternal combustion engine, with inline or V-type configura-tion and including a pressure lubrication system; compris-ing in combination a cylinder block having cylinder bores formed therein, a cylinder head on the upper end of the cy-lindrical bores and closing same and defining a combustion chamber at the upper end of each cylindrical bore, a pis-ton assembly in each of said bores including a piston hav-ing a domed head and a connecting rod operatively connected to said piston for reciprocating same between top dead cen-tre and bottom dead centre, a crankshaft mounted for rota-tion at the base of said block, said connecting rods being operatively connected to said crankshaft and an oil pan en-closing the lower end of the cylinder bores and said crank-shaft, said cylinder head including a cam shaft mounted for rotation thereon and being operatively connected to said crankshaft, at least one inlet-and-scavenger valve mounted on said cylinder head and being operatively connected with said combustion chamber of each of said cylindrical bores, a rocker arm operatively mounted on said cylinder head and operatively engaging said inlet-and-scavenger valve by one end thereof, a cam lobe for each rocker arm formed on said cam shaft operatively connected with the other end of said rocker arm, said cam lobes having a relatively wide area of contact with said rocker arm to control the opening, closing and duration of opening of said inlet-and-scavenger valve and exhaust port located in the lower side of the cylinder walls of the cylinder bores inclining downwardly and out-wardly through the cylinder walls and being covered and un-covered by the reciprocating piston passing thereby.
(2) The invention according to Claim 1 in which said cam lobe opens said inlet-and-scavenger valve at ap-proximately 110° after top dead centre and closing said in-let-and-scavenger valve at approximately 70° after bottom dead centre thereby maintaining said inlet-and-scavenger valve open through approximately 140°.
(3) The invention according to Claim 1 in which said piston uncovers said exhaust port approximately 115 °
after top dead centre and closes said exhaust port approx-imately 65° after bottom dead centre whereby said exhaust port is opened through approximately 130°
(4) The invention according to Claim 2 in which said piston uncovers said exhaust port approximately 115°
after top dead centre and closes said exhaust port approx imately 65° after bottom dead centre whereby said exhaust port is opened through approximately 130°.
(5) The invention according to Claim 4 whereby the overlap between said inlet-and-scavenger valve and said exhaust port is approximately 10° with the inlet-and-scaven-ger valve opening approximately 5° before the exhaust port opens and closes approximately 5° after said exhaust port closes.
(6) The device according to Claim 1 in which said piston assembly includes means to control and reduce the es-cape of lubricating oil therepast, said means including said piston assembly having a domed piston head crown, a piston skirt extending therefrom, wrist pin bosses formed in said skirt below said domed head, sealing caps installed in adja-cent the outer end of each of said wrist pin bosses, to pre-vent the escape of oil therepast, a wrist pin mounted in said wrist pin bosses and operatively connecting said connecting rod to said piston, at least two compression piston rings situated in spaced and parallel grooves in the head of said piston above said wrist pin bosses and at least one oil scra-per ring mounted within an annular groove around the skirt of said piston below said wrist pin bosses, drain holes extend-ing from said groove through said skirt to reduce the escape of lubricating oil through said exhaust port, said oil scra-per ring always remaining below the lowermost edge of said exhaust port when said piston at top dead centre.
(7) The device according to Claim 2 in which said piston assembly includes means to control and reduce the es-cape of lubricating oil therepast, said means including said piston assembly having a domed piston head crown, a piston skirt extending therefrom, wrist pin bosses formed in said skirt below said domed head, sealing caps installed in adja-cent the outer end of each of said wrist pin bosses, to pre-vent the escape of oil therepast, a wrist pin mounted in said wrist pin bosses and operatively connecting said connecting rod to said piston, at least two compression piston rings situated in spaced and parallel grooves in the head of said piston above said wrist pin bosses and at least one oil scra-per ring mounted within an annular groove around the skirt of said piston below said wrist pin bosses, drain holes extend-ing from said groove through said skirt to reduce the escape of lubricating oil through said exhaust port, said oil scra-per ring always remaining below the lowermost edge of said exhaust port when said piston is at top dead centre.
(8) The device according to Claim 3 in which said piston assembly includes means to control and reduce the es-cape of lubricating oil therepast,said means including said piston assembly having a domed piston head crown, a piston skirt extending therefrom, wrist pin bosses formed in said skirt below said domed head, sealing caps installed in adja-cent the outer end of each of said wrist pin bosses, to pre-vent the escape of oil therepast, a wrist pin mounted in said wrist pin bosses and operatively connecting said connecting rod to said piston, at least two compression piston rings situated in spaced and parallel grooves in the head of said piston above said wrist pin bosses and at least one oil scra-per ring mounted within an annular groove around the skirt of said piston below said wrist pin bosses, drain holes extend-ing from said groove through said skirt to reduce the escape of lubricating oil through said exhaust port, said oil scra-per ring always remaining below the lowermost edge of said exhaust port when said piston is at top dead centre.
(9) The device according to Claim 4 in which said piston assembly includes means to control and reduce the es-cape of lubricating oil therepast, said means including said piston assembly having a domed piston head crown, a piston skirt extending therefrom, wrist pin bosses formed in said skirt below said domed head, sealing caps installed in adja-cent the outer end of each of said wrist pin bosses, to pre-vent the escape of oil therepast, a wrist pin mounted in said wrist pin bosses and operatively connecting said connecting rod to said piston, at least two compression piston rings situated in spaced and parâllel grooves in the head of said piston above said wrist pin bosses and at least one oil scra-per ring mounted within an annular groove around the skirt of said piston below said wrist pin bosses, drain holes extend-ing from said groove through said skirk to reduce the escape of lubricating oil through said exhaust port, said oil scra-per ring always remaining below the lowermost edge of said exhaust port when said piston is at top dead centre.
(10) The device according to Claim 5 in which said piston assembly includes means to control and reduce the es-cape of lubricating oil therepast, said means including said piston assembly having a domed piston head crown, a piston skirt extending therefrom, wrist pin bosses formed in said skirt below said domed head, sealing caps installed in adja-cent the outer end of each of said wrist pin bosses, to pre-vent the escape of oil therepast, a wrist pin mounted in said wrist pin bosses and operatively connecting said connecting rod to said piston, at least two compression piston rings situated in spaced and parallel grooves in: the head of said piston above said wrist pin bosses and at least one oil scra-perring mounted within an annular groove around the skirt of said piston below said wrist pin bosses, drain holes extend-ing from said groove through said skirt to reduce the escape of lubricating oil through said exhaust port,said oil scra-per ring always remaining below the lowermost edge of said exhaust port when said piston is at top dead centre.
(11) The invention according to Claim 1 in which said exhaust port is provided with a rectangular configura-tion and inclines downwardly and outwardly upon the lower side of said cylinder wall, said exhaust port being cover-ed and uncovered by said piston as it moves between top dead centre and bottom dead centre within said cylindrical bore.
(12) The invention according to Claims 1, 2 or 3 which includes an air blower component operatively connected to said engine and having an air intake opening and an air outlet, said air outlet being operatively connected to said inlet-and-scavenger valve to supply air in sufficient volume to charge and scavenge said cylinder.
13) The invention according to Claims 1, 2 or 3 which includes a turbo charger and an air blower connected in series thereto, said air blower being operated by the ex-haust gases of said engine, said turbo charger and air blow-er being operatively connected to said inlet-and-scavenger valves to supply air sufficient to charge and scavenge said cylinders.
(14) me invention according to Claims 6, 7 or 8 in which said wrist pin is hollow and is bearingly engaged within said wrist pin bosses, a retainer pin secured to bet-ween said sealing caps, said retainer pin extending freely through said hollow wrist pin, said retainer pin securely retaining said end caps in position spaced slightly inboard from the outer ends of said wrist pin bosses.
(15) The invention according to Claims 9 or 10 in which said wrist pin is hollow and is bearingly engaged within said wrist pin bosses, a retainer pin secured to bet-ween said sealing caps, said retainer pin extending freely through said hollow wrist pin, said retainer pin securely retaining said end caps in position spaced slightly inboard from the outer ends of said wrist pin bosses.
(16) The invention according to Claim l which in-cludes a recirculating type pressure lubrication system and in which lubricating oil is stored in the oil pan and being supplied to all the vital moving parts by means of the pres-sure lubricating pump which is driven by the crankshaft by means of gears, said lubrication system using a micronic oil filter to ensure that clean oil is supplied at all times to the critical moving parts.
(17) The invention according to Claim l in which said cam lobe includes a peripheral contact surface portion engageable with said inlet-and-scavenger valve and extend-m g through approximately 140° of rotation thereby control-ling the opening and closing of said valve and the duration of the opening and closing thereof in relation to the degree of piston travel when the exhaust port is covered and uncover-ediby said piston, said exhaust port being uncovered for ap-proximately 130° and covered for approximately 230° of crank shaft rotation.
(1) A two-stroke supercharged multi-cylinder in-ternal combustion engine, with inline or V-type configura-tion and including a pressure lubrication system; compris-ing in combination a cylinder block having cylinder bores formed therein, a cylinder head on the upper end of the cy-lindrical bores and closing same and defining a combustion chamber at the upper end of each cylindrical bore, a pis-ton assembly in each of said bores including a piston hav-ing a domed head and a connecting rod operatively connected to said piston for reciprocating same between top dead cen-tre and bottom dead centre, a crankshaft mounted for rota-tion at the base of said block, said connecting rods being operatively connected to said crankshaft and an oil pan en-closing the lower end of the cylinder bores and said crank-shaft, said cylinder head including a cam shaft mounted for rotation thereon and being operatively connected to said crankshaft, at least one inlet-and-scavenger valve mounted on said cylinder head and being operatively connected with said combustion chamber of each of said cylindrical bores, a rocker arm operatively mounted on said cylinder head and operatively engaging said inlet-and-scavenger valve by one end thereof, a cam lobe for each rocker arm formed on said cam shaft operatively connected with the other end of said rocker arm, said cam lobes having a relatively wide area of contact with said rocker arm to control the opening, closing and duration of opening of said inlet-and-scavenger valve and exhaust port located in the lower side of the cylinder walls of the cylinder bores inclining downwardly and out-wardly through the cylinder walls and being covered and un-covered by the reciprocating piston passing thereby.
(2) The invention according to Claim 1 in which said cam lobe opens said inlet-and-scavenger valve at ap-proximately 110° after top dead centre and closing said in-let-and-scavenger valve at approximately 70° after bottom dead centre thereby maintaining said inlet-and-scavenger valve open through approximately 140°.
(3) The invention according to Claim 1 in which said piston uncovers said exhaust port approximately 115 °
after top dead centre and closes said exhaust port approx-imately 65° after bottom dead centre whereby said exhaust port is opened through approximately 130°
(4) The invention according to Claim 2 in which said piston uncovers said exhaust port approximately 115°
after top dead centre and closes said exhaust port approx imately 65° after bottom dead centre whereby said exhaust port is opened through approximately 130°.
(5) The invention according to Claim 4 whereby the overlap between said inlet-and-scavenger valve and said exhaust port is approximately 10° with the inlet-and-scaven-ger valve opening approximately 5° before the exhaust port opens and closes approximately 5° after said exhaust port closes.
(6) The device according to Claim 1 in which said piston assembly includes means to control and reduce the es-cape of lubricating oil therepast, said means including said piston assembly having a domed piston head crown, a piston skirt extending therefrom, wrist pin bosses formed in said skirt below said domed head, sealing caps installed in adja-cent the outer end of each of said wrist pin bosses, to pre-vent the escape of oil therepast, a wrist pin mounted in said wrist pin bosses and operatively connecting said connecting rod to said piston, at least two compression piston rings situated in spaced and parallel grooves in the head of said piston above said wrist pin bosses and at least one oil scra-per ring mounted within an annular groove around the skirt of said piston below said wrist pin bosses, drain holes extend-ing from said groove through said skirt to reduce the escape of lubricating oil through said exhaust port, said oil scra-per ring always remaining below the lowermost edge of said exhaust port when said piston at top dead centre.
(7) The device according to Claim 2 in which said piston assembly includes means to control and reduce the es-cape of lubricating oil therepast, said means including said piston assembly having a domed piston head crown, a piston skirt extending therefrom, wrist pin bosses formed in said skirt below said domed head, sealing caps installed in adja-cent the outer end of each of said wrist pin bosses, to pre-vent the escape of oil therepast, a wrist pin mounted in said wrist pin bosses and operatively connecting said connecting rod to said piston, at least two compression piston rings situated in spaced and parallel grooves in the head of said piston above said wrist pin bosses and at least one oil scra-per ring mounted within an annular groove around the skirt of said piston below said wrist pin bosses, drain holes extend-ing from said groove through said skirt to reduce the escape of lubricating oil through said exhaust port, said oil scra-per ring always remaining below the lowermost edge of said exhaust port when said piston is at top dead centre.
(8) The device according to Claim 3 in which said piston assembly includes means to control and reduce the es-cape of lubricating oil therepast,said means including said piston assembly having a domed piston head crown, a piston skirt extending therefrom, wrist pin bosses formed in said skirt below said domed head, sealing caps installed in adja-cent the outer end of each of said wrist pin bosses, to pre-vent the escape of oil therepast, a wrist pin mounted in said wrist pin bosses and operatively connecting said connecting rod to said piston, at least two compression piston rings situated in spaced and parallel grooves in the head of said piston above said wrist pin bosses and at least one oil scra-per ring mounted within an annular groove around the skirt of said piston below said wrist pin bosses, drain holes extend-ing from said groove through said skirt to reduce the escape of lubricating oil through said exhaust port, said oil scra-per ring always remaining below the lowermost edge of said exhaust port when said piston is at top dead centre.
(9) The device according to Claim 4 in which said piston assembly includes means to control and reduce the es-cape of lubricating oil therepast, said means including said piston assembly having a domed piston head crown, a piston skirt extending therefrom, wrist pin bosses formed in said skirt below said domed head, sealing caps installed in adja-cent the outer end of each of said wrist pin bosses, to pre-vent the escape of oil therepast, a wrist pin mounted in said wrist pin bosses and operatively connecting said connecting rod to said piston, at least two compression piston rings situated in spaced and parâllel grooves in the head of said piston above said wrist pin bosses and at least one oil scra-per ring mounted within an annular groove around the skirt of said piston below said wrist pin bosses, drain holes extend-ing from said groove through said skirk to reduce the escape of lubricating oil through said exhaust port, said oil scra-per ring always remaining below the lowermost edge of said exhaust port when said piston is at top dead centre.
(10) The device according to Claim 5 in which said piston assembly includes means to control and reduce the es-cape of lubricating oil therepast, said means including said piston assembly having a domed piston head crown, a piston skirt extending therefrom, wrist pin bosses formed in said skirt below said domed head, sealing caps installed in adja-cent the outer end of each of said wrist pin bosses, to pre-vent the escape of oil therepast, a wrist pin mounted in said wrist pin bosses and operatively connecting said connecting rod to said piston, at least two compression piston rings situated in spaced and parallel grooves in: the head of said piston above said wrist pin bosses and at least one oil scra-perring mounted within an annular groove around the skirt of said piston below said wrist pin bosses, drain holes extend-ing from said groove through said skirt to reduce the escape of lubricating oil through said exhaust port,said oil scra-per ring always remaining below the lowermost edge of said exhaust port when said piston is at top dead centre.
(11) The invention according to Claim 1 in which said exhaust port is provided with a rectangular configura-tion and inclines downwardly and outwardly upon the lower side of said cylinder wall, said exhaust port being cover-ed and uncovered by said piston as it moves between top dead centre and bottom dead centre within said cylindrical bore.
(12) The invention according to Claims 1, 2 or 3 which includes an air blower component operatively connected to said engine and having an air intake opening and an air outlet, said air outlet being operatively connected to said inlet-and-scavenger valve to supply air in sufficient volume to charge and scavenge said cylinder.
13) The invention according to Claims 1, 2 or 3 which includes a turbo charger and an air blower connected in series thereto, said air blower being operated by the ex-haust gases of said engine, said turbo charger and air blow-er being operatively connected to said inlet-and-scavenger valves to supply air sufficient to charge and scavenge said cylinders.
(14) me invention according to Claims 6, 7 or 8 in which said wrist pin is hollow and is bearingly engaged within said wrist pin bosses, a retainer pin secured to bet-ween said sealing caps, said retainer pin extending freely through said hollow wrist pin, said retainer pin securely retaining said end caps in position spaced slightly inboard from the outer ends of said wrist pin bosses.
(15) The invention according to Claims 9 or 10 in which said wrist pin is hollow and is bearingly engaged within said wrist pin bosses, a retainer pin secured to bet-ween said sealing caps, said retainer pin extending freely through said hollow wrist pin, said retainer pin securely retaining said end caps in position spaced slightly inboard from the outer ends of said wrist pin bosses.
(16) The invention according to Claim l which in-cludes a recirculating type pressure lubrication system and in which lubricating oil is stored in the oil pan and being supplied to all the vital moving parts by means of the pres-sure lubricating pump which is driven by the crankshaft by means of gears, said lubrication system using a micronic oil filter to ensure that clean oil is supplied at all times to the critical moving parts.
(17) The invention according to Claim l in which said cam lobe includes a peripheral contact surface portion engageable with said inlet-and-scavenger valve and extend-m g through approximately 140° of rotation thereby control-ling the opening and closing of said valve and the duration of the opening and closing thereof in relation to the degree of piston travel when the exhaust port is covered and uncover-ediby said piston, said exhaust port being uncovered for ap-proximately 130° and covered for approximately 230° of crank shaft rotation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000429236A CA1206102A (en) | 1983-05-30 | 1983-05-30 | Two cycle internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000429236A CA1206102A (en) | 1983-05-30 | 1983-05-30 | Two cycle internal combustion engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1206102A true CA1206102A (en) | 1986-06-17 |
Family
ID=4125356
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000429236A Expired CA1206102A (en) | 1983-05-30 | 1983-05-30 | Two cycle internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1206102A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1997039230A2 (en) * | 1996-04-12 | 1997-10-23 | Ohlmann Hans Armin | Air and exhaust gas management system for a two-cycle internal combustion engine |
-
1983
- 1983-05-30 CA CA000429236A patent/CA1206102A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1997039230A2 (en) * | 1996-04-12 | 1997-10-23 | Ohlmann Hans Armin | Air and exhaust gas management system for a two-cycle internal combustion engine |
| WO1997039230A3 (en) * | 1996-04-12 | 1998-01-29 | Ohlmann Hans Armin | Air and exhaust gas management system for a two-cycle internal combustion engine |
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| MKEX | Expiry |