US2064196A - Internal combustion engine - Google Patents

Description

INTERNAL COMBUSTION ENGINE lFiled oct. 1s, 195o 2 sheets-sheet 1 vAsis/Au: d Asse/m #A5, u A

De :.l15,- 1936.. D. J. 'DESCHAMPS INTERNAL COMBUSTIN ENGINE Filed OGL. 13, 1930 2 ,Sheets-Sheet 2 Pmwm A, A

Patented Dec. 15,v 1-936 o UNITED STATES PATENT OFFICE INTERNAL COMBU STION ENGINE Desire J, Deschamps, st. Louis, Mo., assigner of one-half to P. De C. Ball, St. Louis, Mo.

Application October 13, 1930, Serial No. 488,222

3 Claims. (Cl. 123-4-59) This invention relates generally to two stroke of an internal combustion engine constructed internal combustion engines of the compression in accordance with this invention; ignition type generally known as Diesel engines Figure 2 is a sectional view, taken along the and more particularly to such engines which line 2 2 of Figure l;

are adapted to operate at high speeds suitable Figure 3 is a view in side elevation showing 5 for use in automobiles and aircraft. particularly the manner of driving the sleeve Heretofore internal combustion engines of this valves f of this invention; type have been successfully operated at com- Figure 4 is a perspective view of a valve ele- Daratively' low speeds for industrial purposes, ment employed in accordance with this invenbut such engines have not been capable of opertion;

ation Vat the high speeds .required for engines Figure 5 isa detail view in lend elevation of in aircraft and automobiles'. 'Ihe most imporan element for connecting the valve sleeve with tant limiting features which prevent the use of its drive shaft; and

such engines as haveheretofore been known, for Figure 6 is a detail view in side elevation of automotive purposes, are the fuel injection systhe connecting element showmin Figure A5.. 15 tem and the distribution mechanism. In a two In accordance with this invention, a two- Stroke cycle engine, power output and the` spestroke internal combustion engine of the comcic fuel consumption are principally dependpression ignition typethat is an engine in ent upon the eicacy of scavenging of the cylinwhich ignition takes place by the injection of ders. The scavenging must be accomplished in a quantity of fuel into a chamber inf'which a a relatively short time, during the short part denite volume of air has been highly com- Of the stroke 'of the piston that the exhaust pressed so that 'the temperature is suflicient to ports remain open, and this cannot be thorignite the fuel-is provided with a rotary sleeve oughly accomplished by the methods hereto valve operating in a solid housing and at a speed fore employed in slow and medium speed enless than the speed o'f the crank shaft of the gines. 'Ihe prior distribution mechanisms and engine and preferably at a speed equal to onescavenging systemshave not provided a sumhalf of the crank shaft speed. If operated at cient section for the passage of the exhaust half of the crank shaft speed, the valve is progases and the admission of the scavenging air, vided with diametrically opposite ports, which furthermore, the relative location of the inlet open upon each receding stroke ofthe piston and outlet ports have caused the scavenging air to admit to the cylinder a quantity of slightly to mix to some extent with the exhaust gases, compressed air for removing the fumes` from and, consequently, on the next succeeding cycle the cylinder and which operation is known as the cylinder is partly lled with burned gases, scavenging. As is customary in usual practice, so that efcient operation and complete com-v the one piece. valve housing and the rotary 35 bustion are impossible. sleeve valve extend along over the head of the Thelobject of this invention is, as generally several cylinders of the engine, which necessistated,"t'o provide p, two-stroke internal combus.. tates'the use of a. very long-valve in case of a tion engine `of the compression ignition type .multi-CylindeT-m'lne engineln addmon t0 40 which is capable of Opel-ation at high Speeds the inherent diiiiculty of accurately machining 40 Another object of this invention is to pro such a long sleeve, experience has shown that vide a rotary sleeve valve mechanism for a two'- in such a' long Valve housing and valve. shgho ystroke internal combustion engine which shall distortions are caused by the uneven dostribu' be operated at a speed less than the crankshaft tion of the heat to egect .noven expanslon and speed of the enginecontraction. 'lhese distortions may be of such A more specific object of this invention is to extent as to Shghtly bend the valve or the nous' ing and cause the valve@ to freeze in its housing provide a valve mechanism which shall have a minim n ber of moving parts. by undue increase of local pressure between the f; valve and its housing. other obleots of ons loventlon Wm become The sleeve valve arrangement which is'con- 50 apparoot to thoso sklued m' the art when 12h@ templated by this invention involves a plurality following description isread 1n connection with of sleeve sections having a, uniform rotarymovethe ,accompainymg dramgs m Whlchment in a. solid housing, which acts as abear- Flgure, 1 1S. a view m side elevation, shown ing for the same. The sleevesections are driven partly in sectlon to reveal the operatmg parts by a single slightlynexible drive shaft coaxial 55 therewith, through couplings centered in the bore of the valve elements and so mounted as to eliminate the possibility of so-called freezing between the valve elements and the housing within which they rotate. It will be apparent that by the division of the sleeve valve into a plurality of sections, relative movement between the sections is possible, so that no binding occurs incident to uneven expansion and contraction of the housing. As hereinbefore stated the cylindrical valve sleeves rotate in a solid housing. By the term solid housing it will be understood that the housing .includes an integral cylindrical bore and that no special mechanical devices are used to control the running clearance between the valve and the housing at the various operating temperatures of the engine. The necessity for such mechanical devices is eliminated by this invention wherein use is made of especially selected metals for the construction of the rotary sleeve valve and its housing.

Referring now to the drawings, an internal combustion engine of thecompression ignition type is shown in inverted position, in which position it is preferably operated in aircraft.

The engine of this invention comprises a block i having a plurality of cylinders `I, I D, etc., and

Within each cylinder is slidably mounted a piston 2 in a manner Well known in the art. As hereinbefore stated, the cylinders are in aligned relation within a cylinder block 3 so that the pistons 2 in each cylinder may transmit a power stroke to a common crank shaft. A head 4 is provided for closing the end of the cylinders I, I0, etc., and is formed of a single casting extending across the entire block 3. WithinA the head 4, an integral cylindrical bore 5, extending longitudinally thereof, is formed so that the solid housing, hereinbefore mentioned, remains. The cylindrical housing 5 communicates with each of the cylinders I, I0, etc., through ports 6, 50, etc., which extend through the wall of the head 4 so as to provide a passage between the sleeve and the cylinder. The head 4 and the block 3 are each provided with jackets having spaces `I for the circulation of the cooling medium.

Aslightly flexible shaft 81 is disposed coaxially IWithin the bore 5 and is supported by a suitable bearing cap 9. It will be observed that the bearing cap 9 forms a closure for one end' of the valve housing 5. A bevel gear I I is secured to the shaft 8 at the end thereof outside the cap 9. A bevel' gear I2 is mounted upon the end of a shaft I3 for cooperation with the bevel gear A II to drive the shaft 8 by power from the crank shaft of the engine, which may be delivered to the shaft I3 through any suitablel power-transmitting mechanism. It may be here pointed out that the power-transmittingV mechanism employed with the embodiment illustrated in the drawings is such that the shaft 8 rotates at a speed equal to one-half of the speed ofthe crank shaft of the engine. Y

Within the cylindrical housing 5, a plurality of.valve elements I4, ,I5,v I6, are disposed each of which is adapted to serve a pair of adjacent cylinders, such as I and I0. For the purpose of illustration, these valve .elements are provided three in number, since`- the engine illustrated is of the six cylinder type. Each of the valve elements I4, I5, and I6, is mounted for a close running t within the cylindrical housing 5, so that rotation of the element within the housing is possible. As is clearly illustrated in Figures 1 and 4, the valve element I4 is provided with a pair of diametrically opposite openings I'I and I8 through the wall thereof, which are disposed directly above the port 6 through the wall of thev cylinder head 4, and it will be clearly apparent that upon rotation of the valve element I4, the openings I1 and I8 will alternately come into such a position vthat a passage is opened between the inside of the valve element I4 and the. cylinder I. Since the valve element I4 serves two cylinders of the engine, another pair of diametrically opposite openings such as I9 is provided directly above the adjacent cylinder I0, which upon rotation of the element I4 will become disposed opposite the port 60 of the cylinder I Il to open a passage thereto at the proper time during the operating cycle of the cylinder III.

Referring now particularly to Figure 4, it will be seen that the valveelement I4 is provided about its circumference with a plurality of circumferentially extending grooves 20, 2| and 22, located symmetrically on each side of the ports I1, I8 and I9. It will'be noted that the grooves 2D are provided with angular extensions, such as 23, extending from the groove toward the openings of the valve. The orientation of these angular extensions 23 is such that they operate to dispel lubricant by its inertia upon.the rotation of the valve element 4I4,.to thereby form and maintain a lm of lubricant between the bore of the cylindrical housing 5.

In the wall of the valve housing 5 aredrllled a plurality of small calibrated holes which are in communication with a suitable oil line (not shown) extending along the outer wall of the valve housing 5, this oil line may be connected with the main lubricating system of the engine. One such calibrated hole is disposed directly over each groove 20, so that lubricant is fed to the sleeve'element I4 at the points indicated by arrows in Figure 4, filling the grooves 20 from which it is dispelled over the entire surface of the .valve element I4. The other circumferential grooves 2I and 22 act as small oil reservoirs and hydraulic rings which coact with the lubrieating oil lm to assure the sealing of the cylindrical valve element in its housing 5, so as to prevent the escape of gases to adjacent cylinders through the clearance between the walls of the housing 5 and the valve element I4 such as, for instance, between the ports 6 and 60. The

disposition of these grooves is, of course, similar 'circular grooves 22. 'It will be noticed also that no longitudinal grooves 24 are provided on the portion of surface of the valve element I4, which covers the intake port 6 during the phase of the cycle when the pressure in the combustion chamber of the cylinder is at its maximum value, that f is when the piston 2 is at its top dead centerl position at whichtime combustion of the injected fuel begins.

"amico .these coupling members 2l and 28 are keyed .to

the drive shaft 8 fr rotation therewith. The coupling 21 drives both the valve elements Il and I5, whileV the coupling 28 drives only the last valve element I5. Any. number of valves may, of course, be driven by such connections. Where there is an even number of valves acoupling such as 21 may be arranged to drive each pair. Where there is an odd number of valves, the odd one may be driven by a coupling'such as 28. As previously stated, the shaft 8 is sup-f ported near one end thereof in the bearing 8, so that the elasticity of the metal permits. limited flexing of the lextended portion within thehousing 5. The shaft 8 is centered in the valve elements -by the coupling members 21 and 28, which are provided with-extensions 28, engage with a sliding t within the bore of the'valve element and cooperate with the tongue 28 to center the coupling in .the valve element.

The valve elements being thus lnslidable engagement with the couplings 21 and 28, a limited axial movement of the" valve elements -relative to the shaft 8 is possible when the opposedends of adjacent valve elements do not abut eachl v8 is of a tubular and somewhat ilexible construction; being substantially free at the end within the housing 5, it permits slight distortions of the valve housing 5 without aifecting the seating or freedom of'movement of the valve elements in the housing. In this way, the operation of the valve elements is not impairedby slight bending of the housing incident to uneven expansion and contraction. Y

Since it is necessary that the valve elements Il, I5, and I8 be rotatable within the cylindrical housing 5 and at the same time fitted\therein with sufficient closeness to prevent .the escape of gases from one cylinder through the housing 5 to an adjacent cylinder, and since both the valve elements and the cylinder head are subject to considerable expansion due to the heat of combustion within the engine; it is necessary that provision be made to maintain an even clearance between the valve element and the housing 5.

Furthermore, since it is customary in engines of this type to water cool cylinder heads, the wall of the housing 5 will be constantly cooled by the circulation of lwater thereabout, and in this way Ithe expansion of the valve elements will be greater than the expansionof the sleeve 5 which surrounds them. Although the valveelementsdissipate some heat which they receive from the hot gases in the cylinder to the air which circulates through the valve elements and by contact with the cooled walls of the valve housing, it is apparent that less heat will be dissipated by I the `valve elements than is dissipatedby the housing 5 to the cooling water and, accordingly greater expansion' will occur in the .valve elementsthan occurs in the housing 5.` In order to maintain the desirable clearance between the valve elements and the sleeve 5 under all temperature conditions, so that a close ilt will exist between these elementsto prevent the, flow of gases therebetween and to 'permit -rotation ofl the valve elements. it is desirable that the casting which comprises the cylinder'head l and the housing 5, be formed of aI material having a higher coeillcient of expansion than the valve than the surrounding sleeve 5, the valve elements are preferably formed of a metal having a lower coeillcient of expansion than-the housing 5, and

A heat treated hard alloy steel has been found to be well suited for this purpOSe.. 4Bythus providing a valve element of hard stcel and an outer bearing or housing of a suitable aluminum alloy for snug Aengagement therewith, within which the element is rotatable, it will be found ing 5 to causeexpansion thereof;' and although the sleeve 5 is at a lower temperature than the takes place in the sleeve 5 is, due to its higher coefficient of expansion, substantially equal to the amount of expansion which takes place in the valve elements, so that the fit between these parts is not changed. Furthermore, the bearing qualities of these metals are such as to be extremely desirable for conjoint use.

A plurality ofv exhaust ports 3| areprovided about the wall of the cylinder in such a position that they will be opened by the downward movement of the piston 2 when approaching the end of its travel; and it will be understood that the 'powertransmitting mechanism between'the crank shaftl of the engine and the shaft 8 is such'that one of the openings I1 or I8 in the valve sleeve I4 comes into engagement with the port 6 shortly after the time when the exhaust ports are opened by the movement of the piston 2.

In the operation of an internal combustion engin'e provided with a valve of this-sort, a supply of slightly compressed air is Aadmitted to an elbow at one end of the housing 5 and deliveredwithin the valve element I6. It will thus be seen that the valve elements I4, I5 and I6 act as a conduit for conducting slightly compressed air to the various cylinders upon the opening of the inlet ports 6 thereof. It will be recalled that in the embodimentillustrated, the valve elements I4, I5, and I8 are rotated by the drive shaft 8 ata speed `equal to half. the speed of rotation of the crank shaft of the engine, and' it is thus ap-v parent that each time the piston 2 of the cylinder approaches the position indicated in Figure 1,

one ofthe openings Il or I8 will come adjacent rthe inlet port. 5 topermit an inrush of scavenging air from the valve element I 4 to blowthe exhaust gases to the exhaust ports 3| and illl the cylinder I witli clean air.y

valve element I4, the amount of expansion which The air inlet porti opens a certain. time after I the exhaust ports 3| are opened by the downward movement ofthe piston, Fby this fact the exhaust period becomes thus divided in two distinct periods. The first period, which can be lcalled the exhaust period at highvpressure, ex-

tends from the moment the exhaust ports 3| are opened until vthe air inlet port 6 is opened. During that period the greater part of the burned* gases Aeseapetlirough the exhaust ports; being I forced out by the high pressure still remaining in the cylinder after the combustion of the fuel.

'I'he second period, which is much'longer than 75 to permit the inrush of the slightly compressed scavenging air; this scavenging air travels toward the exhaust ports 3l, forcing the remainder Y of the burned gases out of the cylinder.

When the piston 2 nears its top dead `center position-or, in other words, when the crankshaft of the engine has rotated through 180 degrees, a supply of fuel is injected into the cylinder through one of the nozzles 39 in a manner more fully described in my copending application Serial No. 482,956 led September 19, 193i).

Since it is apparent that many modications will present themselves to those skilled in the art and that many sub-combinations are of utility without reference to other features or sub-combinations, it is to be distinctly understood that such modifications and sub-combinations as do not depart from the spirit of this invention, although not specically described herein, are contemplated by and are within the scope of the appended claims. It is to be furthermore understood that the embodiment here shown and described shall be considered merely illustrative and not in a limiting sense.

Having thus described the invention, what is claimed is:

1. A valve mechanism for a two-stroke inter-` nal combustion engine, comprising, a cylindrical housing having ports communicating with the cylinders of the engine, a plurality of valve elements disposed coaxially within said housing,

a cantilever shaft supported at one end of said housing for rotating-said elements in unison, and means for centering the free end of said shaft within said housing.

2. A valve mechanism for an internal-combustion engine, comprising a cylindrical housing having ports communicating with the cylinders of the engine, -a plurality of successively positioned valve elements disposed coaxially for independent alinement in said housing and having ports cooperating with said rst ports, and a single driving element to which each'of said successive Valve elements is individually and loosely connected so as to permit such independent alinement, said driving element being thereby connected to drive all of said valve elements simultaneously and in xed relation with each other. Y

3. In an internal combustion engine of the characterdescribed having a plurality of longitudinally arranged cylinders, a valve housing having a bore extending along the line of cylinders and having ports communicating with each of the cylinders, and a valve coaxially mounted for rotation in said. bore, ysaid valve having a circumferentially continuous part snugly tting said bore intermediate said ports, said housing being constructed of a metal having a greater coeflicient of thermal expansion thanvthe metal of which the valve is constructed.

DESIRE J. DESCHAMPS.

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