US904807A - Compound explosive-motor. - Google Patents

Description

s. A. REEVE GOMPQUND BXPLOSIVB MOTOR. APPLICATION FILED SEPT, 18, 1906.

Patented Nov. 24, 1908.

4 SHEETS-SHEET 1.

S. A. REEVE.

COMPOUND EXPLOSIVE MOTOR,

APPLICATION FILED SBPT.18,1906.

Patented Nov. 24, 1908.

4 BHBETSSHEET 2.

S. A. RBEVE. COMPOUND EXPLOSIVE mo'ron. APPLICATION FILED SEPT. 18, 1906. 904,807, Patented Nov. 24. 1908.

4 SHEETS-SHEET 3.

S. A. REEVE. CQMPOUND EXPLOSIVE MOTOR. APPLICATION FILED SEPT.18,1906.

m M T m M 9w 3 M4 SIDNEY A. REEVE, O1 WORCESTER, MASSACHUSETTS, ASSIGNOR TO CHARLES F. BROWN,

TRUSTEE,'OF READING, MASSACHUSETTS.

COMPOUND EXPLOSIVE-MOTOR.

' Specification of Letters intent.

Patented Nov. 24, 1908.

Application filed September 18, 1906. Serial No. 835,102.

To all whom it may concern:

Be it known that I, SIDNEY A. REEVE, a citizen of the United States, residing at \Vorcester, in the county of Worcester and State of Massachusetts, have invented certain new and useful Improvements in Com-' pound Explosivedliotors, of which the following is a specification.

This invention relates to explosive engines having compressors external to the explosion cylinder and working on a highrescom ound ex losion en inc embodviu m P P g g y invention. F1 2 represents an enlarged artial verticaflongitudinal section thereof. jigs. 3 4, 5, and 7 represent vertical crosssections on the correspondinglynumbered lines of Fig. 2. Fig. 6 represents a horizontal section on-the line 66 of Fig. 1. Fig. 8 represents a plan diagram of the englue and outsideplpe connections to. indicate the course of the fluids.

The same reference characters represent the same parts in all the views.

Referring to Fig. 8 for a general understanding of the construction of the engine and the cycle performed thereby, 10, 10 are two opposed explosion cylinders with istons connected to ether in a straight ine andalso connector in line with the pistons of two opposed air- compressor cylinders 11, 11 attached to the inner ends of the explosion cylinders. The single moving pistonstructure is indicated at 12 and works upon an oscillating pendulum-beam 13 whereby motion is transmitted to and from a crankshaft 14 through crank-plates 15 and pitman 1.6. A part of the air drawn in from the atmosphere and compressed in the cylinders 11 is discharged through pipes 17, 18, an intercooler 19 and pipes 20 directly to the explosion cylinders 10 whereto the air is admitted by the explosion pistons alternately in the two cylinders at the termination of the power strokes, on the two-cycle plan. A goes through pipes 21, 22 and a liquid-fuel carburetor 23, whereit becomes over-charged with fuel-vapor, and through pipes 24, 25 to the explosion cylinders 10, where the fuelcharged air and the pure air mix in combustible proportions (after some prior .scavenging with pure air) on entering the explosion cylinders. The fuel- air course 21, 22 etc. may be specially cooled if desired, although some cooling is done by evaporation in the carburetor 23. In the explosion cylinders the partially-compressed charge is compressed still hi her on the back-stroke of the pistons, ignited at the top of the stroke, .whereby the pressure is increased still further by combustion, and the charge is expanded and does work in cylinders 10 alternately. At the end of the working stroke the burned charge, still at several atmospheres pressure, is exhausted from the cylinders 10 through pipes 26, whence it passes through a body of water maintained at a constant level in a cooling-chamber 27, and'the combined steam and products of combustion at a low and useful working temperature pass through a pipe 28 to the valve-chest 29 of a steamengine cylinder 30 whose piston is connected with the lower end of the pendulumbeam 13 and operates on the crank-shaft 14 through the pltman 16. After performing work on the lowzpressure piston the working fluid is exhauste to atmosphere or to a condenser, feed-heater or the like. going cycle and suitable ap aratus for perorming it are described an claimed in my prior applications, Serial Nos. 276,719, 311,814, and 322,204, which relate .to the more fundamental features of the engine and c cle.

Re erring now to the particular construction of pistons, fluid passages, valves etc., 31 are the explosion cylinder pistons formed upon the extremities of the moving piston structure 12, and 32 are the compressor pistons formed u on the same structure be tween the exp osion cylinder istons and larger in diameter than the atter. The compressor cylinders 11 are provided with One set (not shown) controls ports 33 (Fig. 6) in the walls of the compressor cylinders which are overrun by the pistons 32 near the ends of their compressing strokes, said ports discharging air to the pipes 17 and the other setof valves 34 control ports leading from the ends of the cylinders and discharging to The foretwo sets of automatic puppet discharge valves.

-of fuel,

the pipes 21. The valves 34 are loaded moreheavily than the over-run valves, so as to open later, pressors always discharge through the valves 34 a fixed volume of air which becomes fuelcharged in the carbureter 23 in passing to the explosion cylinders, while the ports 33 discharge a variable proportion of the compressor volume, according to the working pressure of the system, the proportion being larger at low pressure since the over-run valves then open earlier in the compressing stroke. At the low pressures and consequent expanded volumes, the explosion cylinders cannot take all the charge delivered by the compressors, and much of the air from pipes 20 passes through the explosion cylinder and into the low-pressure cylinder 30 unburned, as scavenging air, the result being a saving by carburizing only a fixed proportionate volume of the output of a fixed-intake air compressor at varying discharge pressures. The above action is more fully explained in my application, Ser. No. 3222M, and is not essential to the present invention, although constituting a preferred construction.

The pure air which passes to the explosion cylinders 10 by way of intercooler 19, (the function of which is to extract the heat of compression and avoid preignition from the further. degree of com ression imparted in the explosion cylinders, esides decreasing the work of compression) enters the explosion.

cylinders 10 directly through entrance ports 35 (Fig. 5) in the walls of said cylinders,

located opposite the exhaust ports 36 in said walls, and uncovered by the pistons 31 at the termination of the respective power strokes, according 'to the well known two stroke cycle. The pistons 31 have the usual deflectors 3?. Earlier in the outstroke each piston 31 uncovers a pair of opposed ports 38, 39 (Figs. 2 and 4) for fuel entrance and supplementary exhaust respectivel the upper port being controlled by 'two ift- valves 40, 41 actuated by cams on a rock-shaft 42, and the lower port controlled by a third lift-valve 43 actuated by a cam on said shaft. Valve 10 controls the entrance of fuel from pipe 25 and it opens latest and closes earliest of the three va ves, substantially at or just after outer dead-center of the piston 31. Valve 41 is an auxiliary air-valve to admit the air supporting combustion (for the air entering by the ort 35 is chiefly devoted to scavenging) ant to clean out the vestibule of port 38 of residual fuel. It controls a passage 44 leading from the air-pi 020 and opens earlier and closes later than uel-valve 40. Auxiliary exhaust-valve 43 controls a passage 4:) leading to the main exhaust pi 1e .26 from port 39. It opens earliest of the three valves, just after the main exhaust-port 36 has been uncovered, and closes latest, thus maintaining the exhaust open after the pis ton 31 has begun its return stroke and causing the initial volume of charge which is to be compressed to be exceeded by thevolume of the ex anded burned charge.

In re erring more particularly to those features which form the embodiment of the present invention, it will be borne in mind that they deal with the problem of handling compression and explosion pressures vastly exceeding the pressures known in the present art. For example, if the first stage of, compression, imparted in the compressors 11, is pounds per square inch absolute, or 6 atmospheres, and the final stage performed in the explosion cylinders 10 is in the same ratio, a compression pressure of 36 atmospheres or 5-10 pounds absolute will be reached. If then combustion adds pressure in the usual ratio, the maximum explosion pressure Wlll be between 1500 and 2500' pounds absolute. These pressures of course may be somewhat departed from in practice without varying the principle. In order to realize and handle these high pressures, I have devised the compound, intercooled, higlrpressure cycle here followed, which is described and claimed in my prior applications before referred to,and have thereby attained a considerable advance in efiiciency over prior heat-engine cycles. The present invention furnishes a type of engine which effectively utilizes and controls the heav forces developed, reduces the amount 0 massive construction which would be involved in attempting to merely adapt present types of engines to this cycle, reduces strains and wear to the minimum, avoids leakage, and provides a compact and accessible arrangement of parts. It may be stated that the type of engine here shown is one especially suitable for large .powers and low rotative speed, but the rincipal features of the invention also app y to lower-powered hi her-speed machines.

he double rocking-beam 13 is hung upon a shaft 46 at the apex of a double A-shaped frame47 having its base on the floor or foundation and extended out at the foot to provide bearings for the crank-shaft 14. Pistonstructure 12 is connected with the beam by a pin 48 in the middle web of said structure. and a double link 49 attached to a pin 50 which is fixed at about the middle of the beam 13 and passes through an elongated slot 51 in said web. Adjustable cross-head slide-plates 52 are attached to the upper and lower sides of the web substantially opposite the pin 48 so as to take the lateral thrust of said pin and support the middle of the piston-structure, and these plates slide on parallel upper and lower guides 53 fixed to the frame.

Pitmnn 16. which lies medially underneath one endpf the upper or explosion-and-compressor part of the engine, has its inner end pivoted by a wrist pin 54 directly to the lower extremity of the beam 13. The latter covers an are which lies mostly to the left of a perpendicular through the beam-pivot 4t and the axis of crank-shaft l4 lies below the level of the axis of pin 54, an expedient which gives increased room for the pitman l6 and crank l5 below the projecting upper structure. 55 represents the piston of lowprcssure expansion cylinder 30, which is double-acting, and thc rod 5t; of said piston runs to a crosshead 5T connected by wristpin 58 and double link 59 with the pin 54 on the extremity of the beam.

Owing to the high compression and explosion pressures peculiar to this cycle it is necessary to make the barrels of the explosion cylinders 10 very strong and of relativelysmall diameter. I prefer to make them of caststeel, which has several times the tensile strength of the usual material, cashiron, but owing to thc ditliculty in making complicated cored passages in a steel casting, I prefer to construct the cylinder barrel and the outer casing containing the water-jacket separately and form the fluid passages and the watenjacket space-in the outer casing, which may be of cast iron. 60 represents the inner cast-steel barrel or liner and (31 the outer cast-iron casing or jacket. Between the outer portions of the two is a jacket space 62 for the circulation of watcr to cool the explosion cylinder. A second cast; liner-piece mounted at the inner end of cylinder jacket t'il and enlarged into a flange beyond the end of the jacket, is clamped by long bolts (ll between the removable head (55 of the compressor cylinder 11 and an enlarged flange. 86 on the jacket 61. and is chambered at B7, 68 J and T) for water circulation and to form the air-admission passage for the compressor admission valve. The latter is a grid-valve til) (seen in Fig. 6) sliding bctwccn the head 5 and the inner end of barrel U0. and it has an upwardly-projecting stem 70 operated by connections hereinafter described. The bolts (ll connect together the barrel of cylinder 1], its head 65, the chambered liner or pltmgcr-bcaring piece 63 and the jacket 61, so that all may readily be taken apart. The exterior base portion of barrel (70 has suitable shoulders and ground joints making pressure-tight connections with the jacket around the ports and inner end of the water-space. and its outer end has a short stem 71 containing the igniter plug 72 and passing through a stuffing-box T3 in the end of jacket (31, whereby inequality of expansion is allowed for. 74 is another axial stem or duct passing through a second stutting-box 75 for carrying a water-jet, lubricant or other fluid to or fromthe interior of the explosion cylinder.

An extension of the explosion cylinder piston or plunger 31 forms the connection between it. and the adjacent. compressor piston 32 and has a long bearing in the piece 63, between which and the steel liner 60 is an annular pocket 160 to catch any leakage of high-pressure fluids from the interior of the piston barrel and return'it to the exhaust port 36. Placing the cylinders 10. ll adjacent to each other with a connecting plurn gear-bearing which may act as a fluid con cluit, diminishes the opportunity for leakage of these high-pressure fluids to the outside of the pressure circuit.

It will be seen that the interiors of the pistons 31 and 32 are chambered for water circulat ion and have compensating telescopic connections 76 with the water-jackets of the compressor cylinders 11, whereby a circulation of water may take place from one compressor cylinder. through the compressor and explosion cylinder pistons of one end and then the other of piston structure 1.2 and finally through the other compressor jacket.

I have shown a simple valveanotion for operating the several valves. The explosion cylinder and low-pressure expander valves are operated from an eccentric 7T 1 and 6), whose rod 78 goes to a T-rockcr 79 pivoted on the A-frame 47. From the lower arm of this rocker, motion is taken for the valve of the steam cylinder 30 and from the lateral arms it is taken b rods 80 to arms on the cam-rockers 42 or the three valves 40, ll, 43 (Fig. 4). For the compressor inlet valves. a motion is compounded of the motions of the pitman it) and the beam 13. A rocker til. lllll lg near thc upper end of the beam. connects by rods 8; and rocker and toggle mechanism 83 with the stems 70 of the compressor inlet-valves an. and from the'pitman 16. motion is conveyed by rod 84, rocker 85 and rod 863 to the rockt-r 81. Sonic oi thcsc valve-connections are omitted from Fig. 3 and other views for the sake of clearncss. Auton'nitic governing may be applie d in any desired manner.

From the foregoing it will be seen that this engine is devised for creating and handling very heavy compression and explosion forces. Considerations of strength and the small, compact volumes handled in the exploders 10 require the barrels and pistons ot' the latter to be of relatively small diameter. and as awrist-pin and pitman of the necessary strength cannot conveniently be luczttctl within the shell of such a piston. after the fashion of ordinary trunk-piston structure. I locate the wrist-pin 4S entirely outside of the exploder pistons. Secondly, experience has shown the desirability of preserving a certain approximate ratio between the cylinder volume, pressure and length of crankstroke in explosion engines. If this ratio were maintained in the present cycle. with the small diameter of explosion cylinder times, the usual volumes and pressures, the

relative axial forces here developed are equivalent to multiplying the area of an ordinary gas-engine piston by ten without increasing its stroke. This would set up strains I and friction greater than engineering experience sanctions for a direct crank-connection. Accordin ly I multiply a relativelyshort piston strolre into a longer crank stroke by means of the rocking beam 13, constituting a lever of the third class. The cross levenconnection also carries the crank-shaft out of the plane of the explosion cylinder axis and brings the pitman 16 off to one side of the explosion cylinder and compressor structure, in a readi y accessible position, besides permitting the use of a single itman. Ina horizontal engine,the pitman an crankshaft are thus brought near the floor or osition of greatest stability. The multiplled movement increases the stroke of the lowpressure piston 55, which handles expanded volumes from the exploders 10, and enables its diameter to be kept small.

It will further be seen that the low-pressure expander and its connections with the lower end of beam 13 are all readily accessible, apart from the superstructure, and may when desired be disconnected from the rest of the engine or entirely omitted, without disturbing the mechanical balance or working action of the remainin parts. In that case the exhaust of the explosion cylinders 10 may be led through a water-chamber such as 27 (Fig. 8) to any separately-running engine of the steam-engine type. The superstructure then becomes a sourceof compressed-air and pressure exhaust-gases for a disconnected taking engine, and, if the explosion cylinders are not intended to give any appreciable mechanical power to their crankshaft, the design of the compressors will be such as to absorb substantially all of the pmver of the explosion cylinders. In the latter event the multiplied crank-motion is not so essential because the crank receives only a small ,proportion of the total power, but I still prefer to retain a cross lever connection to the crank on account of advaniagcs mentioned her ein. Thirdly, simplicity, compactness, balance and direct transmission of force from explosion cylinder to compressor are gained by mounting the explosion cylinder and compressor pistons in line on the same moving piston-structure. Some of the advantages of my invention inhere in the single compound unit or pair composed of the left-hand explosion cylinder and the right-hand compressor or the right-hand explosion cylinder and left-hand compressor; taken together with the beam-connections and either with or without the combination of the low-pressure expander connected in 'the manner described; but several additional advantages arise from doubling this unit in the way shown by the drawings or in any equivalent manner. One advantage is that the crank-shaft receives an explosive powerimpulse in each direction and these powerimpulses are both used to perform highstage compression in the opposite explosion cylinder, and low-stage compression in the opposite compressor, giving a superior balance and absorption of forces. A further advantage of the particular embodiment of right-hand and left-hand groups here shown is that a low-stage compressor is ldcated adjacent each high-stage explosion cylinder, to counteract the opportunity for leakage from the latter and diminish the requirement for a perfect packed piston-rod joint. Lubrication is also somewhat more easily performed, and a very compact structureafiorded. The inertia of the large double piston structure is utilized in securing steadiness of pressure on the pins. These inertia forces arise on the one hand from the setting in motion of a heavy weight of metal by means of a high explosive force and are absorbed on the other hand by the high compression resistances which tend to arrest such motion. Thus while the compound cycle gives rise to much heavier forces than usual, the compound unit-piston structure affords an opportunity to handle these forces to a large extent by inertia without inserting bodies of dead metal.

I claim 1. An internal-combustion engine comprising a low-stage charge-compressor, an o posed explosion motor adapted to multip y the compression imparted by said chargecompressor, a common reciprocating piston structure for the two, a crank-shaft, a rocking lever having a connection with said piston-structure between the pistons of the compressor and motor, and a pitman connected at a point on said lever which gives a crankstroke of other length than the piston stroke.

2. The combination of opposed compression and explosion cylinders adapted to perform successive stages of a serial charge compression, a common piston-structure having a compression-cylinder piston formed on one portion and an explosion-cylinder piston of smaller effective area formed at its opposite end, a crank-shaft, a crank of longer stroke than the piston-stroke, a motion-multiplying connection from said piston-structure to the crank, and means for creating a substantial back-pressure to the exhaust of the explosion cylinder.

3. An internal-combustion engine comprising a high-pressure explosion motor and an opposed charge-compressor therefor having a common piston-structure, means to create a substantial back-pressure to the high-pressure exhaust, a crank, and a lever of the third class connectin said piston-structure and crank for multiplying the motion from the former to the latter.

4. An internal-combustion engine comprising a high-stage compression explosion cylinder and a low-stage charge-compressor therefor having a common piston-structure, a lowstage piston expander for said explosion cylinder, whose axis is located off the axis of the latter, and a cross lever-connection between said piston-structure and the piston of the ex ander.

5. An internal-combustion engine comprising an explosion motor and an opposed charge-compressor therefor having a common piston-structure, a crank, a lever connecting said piston-structure and crank for multiplying the piston motion, and a lowpressure expander for said motor having its piston connected with a motion-multiplying point on said lever.

B. The combination of a two-stroke cycle internal compressing high pressure explosion cylinder, an opposite charging cylinder therefor, means to create a substantial backpressure to the exhaust of the explosion cylinder, a piston-structure common to the two cylinders, having formed on one end the explosion-cylinder piston and on its opposite portion the compressor piston of larger efective area, a crank having a. longer stroke than the piston-stroke, and motion-multiplying mechanism connecting said piston-structure wlth the crank.

7. An internal-combustion engine comprising two high-stage internal-compression explosion cylinders and two low-stage chargecompressors therefor arranged in opposite groups each including an explosion cy inder and a compressor, means to create a substantial back-pressure to the high-pressure exhaust, a common piston-structure having compressor pistons and explosion-cylinder pistons of smaller effective area, an offset crank-shaft, and a lever taking motion to said crank-shaft from a point on the pistonstructure between the said groups.

8. An internal-combustion engine comprising two explosion-cylinders and two compressors therefor arranged in opposite groups each including an explosion cylinder and compressor, a common piston-structure, an ofiset low-stage piston expander common to the two explosion cylinders, an offset crankshaft, and connections between said pistonstructure,-the expander piston and the crankshaft.

9. An internal-combustion engine comprising opposed groups of explosion cylinders and compressors having a common piston- In testimony whereof I have hereunto set my hand in the resence of two subscribing witnesses, the 13t day of September 1906.

"SIDNEY A. REEVE.

Witnesses G. W. -HOPKINS, R.'M. Pmnsox.

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