US2401631A - Engine - Google Patents

Description

June 4, 1946. w. G. GERNANDT ENGINE Filed Feb. 28. 1944 s sheets-sheet 1 m \"mw #magy/ l June 4, w. G. zaERNsmD-rA ENGINE Filed Feb. 28, 1944 3 Sheets-Sheet 5 Patented .nlune '4, 1946 NT oFFlcEj ENGINE Walde G. Gewenst, Detroit, Mien., assigner to Briggs Manufacturing Company, Detroit, Mich., a corporation of Michigan Application February 28, 1944, Serial No. 524,165

' 1s claims. (cl. 12s-so) This invention relates to internal combustion engines and particularly to the type of engine inwhich a rotatable valve is provided for controlling the intake and exhaust and the firing of the combustible mixture.

The present invention is particularly applicable tov an internal combustion. engine of the kind in which the rotatable valve in the head, preferably although not necessarily rotatable continuously in one direction, is formed with substantially all or at least the maior portion of the combustion chamber at the time of firing and is generally conical or truste-conical in shape, The combustion chamber within the rotor or rotary valvehas an opening at one end leading to the cylinder and a second opening preferably at a sidethereoi to communicate during operation with an outlet or inlet passage, or bothv v as tbe'casemay begand the combustible charge within the combustion chamber is med preferablybysparkignition. Hanydimculties -are encountered. in the production of a satisfactoryengine ofthe vforegoing. typolone of the` moet serious being-in connection' with the lubrication of the rotaryvalve andin 'other objects of thisl invention wm appear in ings forming a part ofthis specication wherein like reference characters designate correspond- `ing parts'in the several views.

the consumption-of lubricating eik Not only is `it important that proper lubrication of the lvalve be provided butalsov thatthe valve be constructed so 'as to preclude building up oLexcessb/eV pres-- sures at certain loca1ities, due to thermal expan"L sionof the valve, tending to destroy the oil'lm. It is also important that provision be made for adequate delivery of oil at localities where the greatest load occurs during; operation.; 'A further important consideration, additional to adequate lubrication and control ofvalve expansion, is the pressure side ofthe valve'bearingsurface'in the cylinder head and spread in a iilm over the bearpiston.

A further object of the invention is to.pro A vide an improved valve construction whereby excessive friction between the valve and cylinder ing clearances between the valve achieved during operation,

the following description and appendedclaims, reference beinghad to the accompanyim draw- Fig. lis a fragmentary sectional elevation illustrating a portion of a multi-cylinder engine emthrough lines-1 2 bring. 1 100km 1n the direc;

tion of the arrows.

Fig. 3 is a fragmentary side lelevation illustratil ing one of the'cylinder heads.

substantially through lines 4 --4l of Fig; 3.1ookins in the directionr of the arrows.l

matter of oil consumption which in itself presents a serious problem owing to the tendency to excessive oil consumption consequent` to the use of rotary valve constructions.

One of the objects ofthe present invention is to provide a lubricating means for a rotatable valve of the above type of engine which will be more eiilcient and accurate thereby improving' the operation of the engine and reducing oil con..

sumption.

A furtherobject of the invention is to control thedelivery of oil to the rotatable valve so that adequate lubrication will be available at desired localities while at the same time providing for the removal of excess oil not needed for lubrication purposes. l l

Still anotherobject of the invention is to provide improved lubricating means for the valve by which lubricating oil is introduced at the high Fig. 5 is e fragmentary view faken' substantie" inthe direction from lines V5-4-5 of Fig. 4 looking of the arrows. j

Fig. 6 isal view similarto Fig. 4'illustrating, a further embodiment ofthe' invention, g

Fig. 7' is a fragmentary view taken substantially from lines 1 1 of Fig. 6 looking inthe direction of the arrows.

Fig. 8 is a. fragmentary sectional view, in part e' .diagrammaticaL illustrating clearances between the Vvalve and cylinder head, the samev being v somewhat exaggerated for the purpose of showing more clearly the features of this construction..

Fig. 9 is a'view similar to Fig.' 7 illustrating another embodiment'of the invention. Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and' arrangement of parts illus-` trated in the'ac'companying drawings, since the invention is capable of other embodiments and e Fig. 4` is an enlarged fragmentary section .taken y 4 l time of firing, is formed within the valve.

asomar or terminology employed herein is for the purpose of description and not oi limitation.

In the drawings there are illustrated, by way of example, certain embodiments of the present invention asapplied to an internal combustion engine of the spark ignition type which may be used for the power plantof an aircraft or motor vehicle or for other purposes, such as for marine and industrial engines. For most usesthe engine is of the multi-cylinder type, although any number of cylinder units may be employed in any given engine. In the4 present embodiments,

for the purposes of simplicity, a single .cylinder unit of the engine ,is illustrated, it being understood that the remaining cylinders of the engine are substantially identical to the structure herein shown' and described.

Referring to Fig.. y1, the present engine comprises a suitable crankcase 20 carrying a cylinder 2| within which a piston 22 is mounted for reciprocation. A crankshaft (not shown) is supported in suitable bearings in the crankcase accordingV to conventional practice and the piston is connected to the crankshaft by a connecting rod 23.

The present engine, for the purposes of illustration, is of the liquid cooled type and-accordingly, the cylinder 2i is mounted within a cylinder jacket 24, the lower end of whichV is brazed or otherwise secured to the -crankcase y2li. Be-

' y.tween the .cylinder jacket 24 and the cylinder is a liquidl coolant chamber 25. yThe enginevfalso comprises a cylinder head 26 having a .tapped hole into which the upper end ofthe cylinder threadedqaut 26a. The cylinder head `is c ast to-provide a' depending. cylinder lhead Jacket 21 V- yforming aliquid coolant chamber 28 'communieating with the chamber. The lower thickened edge of the cylinder lhead Jacket 2.1. is provided with an annular groove within which is received a resilient rubber sealing .ring 29 engaging the upper outer wall of the'cylinder jacket 2B and placed under compression when the upper lend of this jacket is forced into position, as shown,

. within the opening at the lower end of the cylinder head jacket. The sealing ring 29, being pressed tightly against the cylinder jacket 24,

provides a liquid tight seal against leakage of the dium. "I'his chamber is sealed at its upper endby means of an expansion plug or disk d2 mounted within a bore in the projecting `stem 43 of the valve.

As more particularly illustrated in Fig. 8, the outer wall of the valve 33 is relieved circumferentially at dit. This relief area preferably extends substantially entirely around the valve in the height of the side port 35. In the illustrated embodiment the height of this circumferential relief 'area 44 corresponds substantially to the heightof the side port 35. It will be noted, as shown in Fig, 8, that this relief area increases somewhat in depth from the upper to the lower edge thereof. Also it will be noted that immediately above the upper edge of this relief area 4l the outer wall of the valve is slightly relieved at 4,5, but this latter relief diminishes to a point where the clearance between the valve and wall ofuthe valve housing 3| does not exceed an` ordinaryrunning or operatingclearance. Below the lower. edge of, the relieved-area 44 the valve wall providedwith a .circumferential relieved area 46 normally providing, when y.the valve is cold, a v,clearance with respectl tothe adjacent wall of the valve housing 3l, whichmay exceed a normal running or operatingclearanceby one to one 'and one-half thousandths of an inch. Below the relieved areaV 46, which area extends continuously around the valve immediately below the side port 35, the wall "of the valve is additionally relieved toprovide an annular tapered or bevelled area 41 extending entirely around the valve and having a clearance at its'lower edge 41a with respect to the wall of the valve coolant from the communicating chambers 25, 28. v

The lower end of the cylinder 2l, in the present embodiment, has a sliding fit within an opening in the crankcase `2l) and the Joint between the cylinder and crankcase svsealed by means of sealing rings 39.'

The cylinder head 26 is formed with a valve housing 3i, largely surrounded by the coolant chamber 28 and provided with a generally frustoconical cavity 32 within which is rotatably mounted a generally frusto-conical valve 33, it being understood that the outer tapering wall of the valve corresponds generally to the shape of the juxtaposed wall oi the cavity 32. The valve 33 is provided with ay combustion chamber 34 having a bottom port 3S, arranged in constant Y communication with the cylinder, and a side port 35 adapted to register' in succession, during rotation of the valve, with a spark plug 37 at the spark plug'locaton 39, an exhaust conduit 39 in the cylinder head, and an intake conduit 40 also inthe cylinder head.

The piston 22 is preferably formed at its outer end with a tapered portion which projects into housing 3i, which may` exceed 'an ordinary running or operating -clearance by some four thousandths to six thousandths of an inch. The bottom surface 33a of the valve 33 has an upward inclination or taper corresponding to the taper of the top surface ofthe piston. 'I'his bottom inclined or tapered surface 33a of the-valve terminates in an annular upwardly extending bevel or taper ed which, las shown in Fig. 8, terminatesat the lower edge 41a of the relieved area di'. It will be seen from Fig. 8 that the corner or. juncture lila of the tapered surfaces 4l and 48 is normally spaced inwardly from the upper edge o the cylinder 2l which has an annular bevel 49 at this locality. Although the above described -relieved areas are preferably provided in the wall.

of the valvev 33, it will be understood that one or more thereof may be formed in the wall 32 of Les valve housing 3|, and in particular the relieved area 44 may be constructed and serve the purposes` in accordance with copending application Serial No. 495,260, iiled July 19, 1943.

In laccordance with the present invention l means is provided for lubricating the vbearing surfaces of the valve 33 and the valve yhousing 3| below the side port 3E and the annular relief 44 in the valve. Referring to Figs. 2 to 5 inclusive,

the cylinder head at a pointbetween the exhaust passage 33` and intake passage di! and closer to the former is drilled, counterboredand tapped to provide an opening 5I! into which is connected an oil inlet pipe I through which lubricating oil is introduced under suitable pressure by any conventional oil pump connected to a source of sup- Ply. Extending from the inlet opening 50 is an inlet passage 50a which in turn communicates with a smaller drilled hole 52 leading to a Dort v 53 opening through the inner wall 52 of the valve housing 3|, ,4 The inlet port 55 ispreferably located at a point near the lower end of the valve relief 45 but above the bevelled or tapered relief area 41 inthe valve,'as shown in Fig. 8. The inlet port 53 communicates with an angu larly extending distributing oil groove 54 which' end of a drilled hole 55 forming an outlet passage through the wall of the valve housing. The 1 passage or duct 55 terminates in an enlarged tappedhole 51 into which is secured the threaded end of e,4 coupling to which is connected a pipe 58 leading to a vacuum pump 59 or other source of suction or reduced pressure. As hereinafter described, suction induced by the -pump 55 in the suction line 55-58 will withdraw excess oil entering the oil pressure groove 54 ,from theinlet pressure line 50-52.

In the event it is desired to supplement the passage 56 and withdraw lubricating oil from the bearing surfaces at any desired point or points circumferentially spaced from the groove 54 and port 55,v additional means may be provided for this purpose as illustrated in Figs. 6 and 'l and also in Fig. 2. In this embodiment the wail of the valve housing is provided with angularly` related divergingoil collector'grooves 55 and 5l positioned in the height of the groove 54 andcircumferentially spaced therefrom at any desiredl distance. A similar pair'of diverging collector grooves 52 and 53 may be provided at a suitable Adistance from the grooves 50 and 5I, and both pairs, as shown in Fig.y '1,' connected by a communicatinggroove 54 leading to a port 55 at the end of a drilled oil passage 55 communicating with A the outlet opening 51. Thus, during operation of d the vacuum pump 55. the suction induced in the formed inthe wall of the valve housing 3| above Fig. 9 an adextends upwardly in the wall 32 of the valve'housving and'terminates in an outlet port 55 at'the 15T and below the oil pressure groove 54 and at a suitable distance therefrom. These grooves 51 and 55 'will lie near the upper and lower edges ofthe relieved area "in the valve and may extend in substantially parallel relation as shown in I"ig.'9. The collector grooves 51 and 55 com# municate with drilled oil-passages 55 and. which in turn communicate with the opening 51 so that suction induced in the line 55 will. cause oil to be withdrawn from the collector grooves 51 and 5l.v

The valve. is driven at one-half engine or crankshaft speed through the medium of the projecting stem 45. Such driving mechanism for the valve is more fully shown and described in my January 15, 1944. The valve is yieldinglyheld up wardly within the frustofconical recess l! in the i 6 erted by the spring to raise the valve within the valve housing is suillcient to substantially offset or equal the effort exerted during the suction stroke of the piston to draw the valve downwardly and away from its seat. d

It will be understood that other suitable source of suction or reduced pressure than the pump 59 may be provided, and that the oil withdrawn from the collector grooves and distributing groove is returned to the oil sump or source of supply and thence returned tothe bearing surfaces by the usual oil pump. The oil grooves are located at the pressure side of the valve oppostethe spark plug at the .locality where the'greatest load comes at the time of firing, thus ensuring maintenance of an adequate oil film at Vthe bearing surfaces most subject to friction and scoring duringoperation. By using a scavenge p uxnp 59 to withdraw excess `oil itis possible, and preferred, to produce a suction effort or negative pressurein the oil exhaust conduit 58 at all times somewhat in excess than the maximum suction effort or negative pressure in the cylinder during the suction stroke of the piston, especially when running idle. This enables excess oil to be returned by the pump to the oil sump rather than be drawn into the cylinder `and as a consequence reduces oil consumption materially. d

It vwill be seen that a circulation of oil to and from the valve bearing surface is maintained while `at the same time control of the amount of oil actually delivered `to and spread over the bearing surfaces by the wiping action of the valve is also ensured. It is desirable that the oil be delivered through duct 52 and. flow into'and through the distributing" groove 54 under pressure, or in other words that a, pressure circula- "tion of Voil through all passages andgrooves be maintained, thereby preventing the accumulation or formation of carbon tending to clog the passages. It is also important that the distributing and collector grooves be connected to a source of reduced pressure or suction so as .not-only to A maintain a circulating flow of oil but also to withdraw excess oil from the bearing' surfaces. With this construction, namely, the use of a suction system to enhance circulation of oil it is possible to more accurately control the oil nlm, the

amount of o il actually distributed over the bear- 'ing surfaces, and the consumption thereof.

It will be understood that the size and length of the oil grooves and their respective positions will be governed by the requirements and design -copendin'g applicationY Serial No. 518.323, filed valve housing by means of aV compression spring 1i which is held under constant compression against a steel coupling disk 'I2 which in turn is heldin place by a nut 15 engaging a bolt 14 of the particular engine, the present construction being shown for illustrative purposes.

Y The annular relief areas 45 `and 41 are im portant in ena-bling proper lubrication to be maintained and preventing destruction crimpairme'nt of the oil film during operation. These relief areas. which. may be termed expansion re liefs, offset expansion of the valve outwardly towardV the valve bearing surface of the cylinder l such that when the valve is hottest during operation andmaximum expansion thereof `has occurred, the valve surfaces will have substantiallyv a normal running or operating clearance throughout these areas with the bearing wall Il of the cylinder head. The relief area M extending in the height of the valve is preferably of a depth to permit carbon to form therein, so that after continued operation this relief will be filled with carbon and provide an excellent bearing not requiring any direct lubrication with oil. This construction and the advantages thereof are more particularly described in the above mentioned copending application.

I claim: I

1. In an internal combustion engine having a cylinder, a body, alrotatable valve in said body associated with said cylinder and having a combustion chamber therein. a conduit in said body for delivering oil to a groove in the valve bearing surface of the body, and a collector oil groove in said surface spaced from said first named groove and connected to a source of suction.

2. In an internal combustion engine having a cylinder, a body, a rotatable valve in said body associated -with said cylinder and having a combustion chamber therein, a conduit in said` body for delivering oil to a groove in the valve bearing -surface of the body, a collector groove in said surface spaced from said first named groove, and means for connecting said collector groove and first named groove to a source of suction or suction.

3. In an internal combustion engine having a cylinder, a body, a rotatable valve in said body associated with said cylinder and .having a combustion chamber therein, a conduit in' said body for delivering oil to a groove in the valve bearing surface of the body, and a collector oil groove in said surface spaced from said first named groove in a direction circumferentially of the 5. In an internal combustion engine having a cylinder, a cylinder head, a rotatable generally frusta-conical valve in `said head having a com.` bustion cham-ber and a side port communicating.

therewith, an oil inlet conduit in said head for delivering cil to the valve. a distributing groove in the valve bearing surface of the head connected to said conduit, and conduit means con nected to a source of suction or reduced pressure and communicating with said groove below said port, said groove being located below saidport and above the lower edge of thevalve.

6. In an internal combustion engine having .a

increasing depth toward said widerend, said relieved area comprising portions ofdifferent depths, the portion of greatest depth extending around the valve proximate to the cylinder.

8. In an int'ernal combustion engine having a' cylinder, a cylinder head, a rotatable generally frusta-conical valve in said head having a combustion chamber and a side port communicating therewith, said valve vhaving a circumferential relieved area below said port of increasing depth terminating in an annular bevel forming an expansion relief of greater depth than said relieved area.

9.. In an internal combustion engine having a cylinder, a cylinder head, a rotatable generally frusto-conical valve in said head having a com- I bustion chamber and a side portv communicating therewith, said valve being positioned with its wider end adjacent the cylinder and having a cincumferential relieved area below said port of increasing depth toward said wider end, and means l1. In an internal combustionengine having a.

cylinder. a cylinder head, a rotatable valve in said head associated with the cylinder, said head having abearing surface for the valve and oil inlet and outlet conduits, and oil groove means in said surface opening toward the valve and connected to said conduits at points spaced axially of the valve intermediate the ends thereof.

12. In an internal combustion engine having a cylinder, a body, a rotatable valve in said body associated with said cylinder, Lan oil groove in the body opening toward the valve for distributing oil to a circumferential area of the valve bearing surface of the head extending in the height of said groove, means for delivering oil to said groove, and means for withdrawing oil from the valve bearing surface within said area. i

13. In an internal combustion engine having a surface of the head extending in the height of.

said groove, means for delivering oil to said groove,

and ,means for withdrawing oil from the valve bearing surface at a locality spaced from said cylinder, a cylinder head, a rotatable generally frusto-conical valve in said head having a combustion chamber and a side port communicating therewith, said valve being positioned with its wider end adjacent the cylinder and having a circumferential relieved area below said port of increasing depth toward said wider'end.`

7. In an internal combustion engine having a cylinder, a cylinder head, a rotatable generally frusto-'conical valve in said head having a combustion chamber and aside port communicating therewith, said valve being positionedwith its wider end adjacent the cylinder and having a4 circumferential relieved area belowsaid port of groove circumferentially of the valve.

.at a point or points spaced fromsaid groove axially of the valve.

15; In an internal combustion engine having a cylinder, a body, a rotatable -valve in said body associated with said cylinder, an oil groove in theA body opening toward the valve for distributing oil to a circmnferentisl area of the valve bearing suriaee of the head extending in theheight of said groove. an oil inlet conduit for delivering oil to said groove, and conduit means for conveying oil from the valve surface within said area.

16. In an internal combustion engine having a cylinder. a body, a rotatable valve in said body associated with said cylinder, an oil groove in the bodyl opening toward the valve for distributing oil to n circumferential area of the valve bearingr lo surface of the head extending in the height of said groove, an oil inlet conduit for delivering oil to said-groove, and conduit means for conveying oil from the valve surface within said areaat a locality spaced from said groove circumferentially 13 ofthevalve.

17. Inan internal combustion engine having a cylinder. a body, a rotatable valve in said body associated with said cylinder. an oil groove in the 10 body opening toward the valve for distributing oil to a circumferential ares of the valve besrinz surface o! the head extending in the height of saidv groove, an oil inlet conduit for delivering oil to said groove at a predetermined point, and conduit means for conveying oil from 'the valve bearing surface at points at opposite sides of saicl point of delivery.

18. In an internal combustion engine having a cylinder. a body,'a rotatable valve in said body

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