US2006372A - Engine - Google Patents

Description

W. H. STONE ENGINE Filed July 9, 1932 3 Sheets-Sheet l I INVENTOR.

WILLIAMMJWE I 17/5 ATTORNEY of present design.

Patented July 2 1935 ENGINE:

' g William n. Stone, Santa Barbara, Calif.

Application Jilly 9, 1932, Serial N5 621,554 i 1 Claim. (01. v i-.55

fQAnother object of my invention is to provide an enginein which the-energy availableat the piston is appliedto the drivenshaft as a, torque act ing-with a, substantially constant level" arm; in-

' stead of a torque acting with ra lever arm which varies from zero to the length of the crank arm as in thefu'su'alcrank' shaft moton V Another'object' of rnyinventioh isto'providean internal combustionengine in which the piston strokes my be of different length, so that a'i'motor design maybe effected in which the expansion ratio is greater man; the compression ratio. l Another object of my invention is to provide 7 an engine of the character described which is capable of higher piston speeds with respect to driven'or crank shaft speeds than'is possible v theordinary motors of present design; "Another; object of my nventio'n is an'engine Which'perrnits a more rapid'and completeexpansion of the gases under combustion, so s to' effect less'loss of power in exhaust and. radiation. i i f a 1 Another object of my invention is to provide an'engine which is capable of and able to maintain a better mechanical balance than'the-crank shaft type'o'f motor. e Stillenother objecto f my invention is to'provide' an engine in which the mechanical causes of piston'sla'ps and detonation' knocks are largely eliminated. 5

" jA further object of my invention is to provide an internal combustion engine whose operation v approaches that of a constant torque motor.

I A still further object of my invention is to ac coniplish' thev above objects by an engine which is morecomp'act in structure, lighter inw'eight, possesses fewer working parts; and which operates with less noise and vibration than the ordinary internalcoinhustionmotor. I f .The invention possesses other objects andwfeatuiesadvantage, some-of which; with the foregoing will be set forth in thefollowing description of my invention. It is to be undei'stood that I do not limit myself to this disclosure of ofrnyinvention; as I may adopt variant embodiments thereof within the scope of theclaim Referring to the drawings? Figure 1 is a vertical sectional View showing an engine embodying nay-invention; the plane 10f section being taken transversely of the driven to provide shaft and through the centerlines o'fthe' two forward cylinders, except at the" heads of the cylinders where 'the plane is brought-forward to theaxis of one of the valveshanks.- l v Figure 2 is a vertical sectional'view ofthe same taken'in a plane passing through the driven shaft axis and at right angles to the center lines of the two forwardc'ylindersshownin Figured? I I Figures 3 to are vertical sectional views, largely diagrammatic, taken in-aTplane transverselyofthe drivenshaft'and through the center lines of the two forward cylinders; 'theseWiews 1 showing the relation between the pi'stonsand the track-at the beginning of theseveral strokes' 7 Figure 7 is atran's'verse vertical'sectional view taken in a plane through the axis ofthecylinder, andillustrates a variant forni oftrack amen: gagi'n'gelement construction;- 1'

Figure 8 is a diagrammatic viewshowing the manner in which the traces-1am out for the firing-stroke, i v I Figure 9 is a diagrammatic view showing the relation betweenthe various strokes 'of a piston.

Inte'rms "of broad inclusion, the engine embodyin'g my invention comprises 'ashaft' having an endless track mounted for rotation therewith. Atrack engaging' element is provided, and guide means are provided" for limiting-movementof the element along an axis spaced from the shaft axi ir e'ans' are a'ls'dpreferably provided for movingth'e track-engaging element; the track being preferably-designed to accord with a-recip= rocating' motionarns engaging element.- fThe means fori-im'oving the track-engaging element preferably"comprisesa cylinderhaving a. piston working therein; together with means connecting the "track engaging elementfor movement with thepiston; i I 1 By this 'meehanisin the reciprocating motion of thevlpiston istran'slated into a rotary motion of the Shaft vvlthtmt" involving the usual crank 'i Shaft dead centers, and the energy-available at the pistonis' applied to th e shaft as a torque acting i .with a substantially c-onstantle've'r arm. When In greater detail the'e ngineen'ibodying my in- I vention is described-as afour'cycleinternal coin-' bustion engine in which the four? cycles are corn pleted in one revolution of theshaft being driven,

eiit lengths. It is 'to be understoodhowever' that this particular embodiment of my "invention is shown merely for purposes of illustration in order to show the various features of my improved mechanism. Referring particularly to Figures 1 and 2, the engine comprises a straight shaft 2 which replaces the ordinary crank shaft. A plurality of spaced driving disks 3 are mountedon the shaft 2; in the four cylinder motor shown there are preferably three of these disks. 7

The cylinders are positioned on opposite sides of the shaft 2 being driven, and two of the cylinders, 4 and 6, are arranged between one pair of the disks 3, while the other two cylinders, 1 and 8, are arranged between the otherpair ,of disks.

The cylinders in a pair are arranged substantially. parallel and are positioned with their heads ex-' tending in opposite directions. Also, the cylinders in one pair are preferablypositionedat substantally right angles to the cylinders in the other pair. This arrangement of thecylinders is probably best shown in Figure 1.

Each cylinder is provided with a piston 9 fixed on the end of a connecting rod The outer end of each rod is connected with a crosshead 2 slidably arranged in the guideways l3. The crosshead I2 is preferably circular in shape and the guideways l3 are preferably formed as extensions of the cylinder walls, the slot-like openings being provided between the guideways to allow passage of projecting portions I6 'of the crosshead. A shaft IT is mounted in the tubular portions I6 of the crosshead l2 and carries adjacent the ends thereof a pair of rollers 8 positioned adjacent the opposing surfaces of the driving disks 3. 1

A third roller I9 is also mounted on the shaft I1 and is positioned alongside the outer roller I8. These rollers are freely journaled on suitable bearings, such as the ball-bearings 20. By this arrangement it is apparent that the crosshead l2 and consequently the rollers l8 and |9 are con-. nected for reciprocation with the piston 19,, andare limitedin their movement to a path along an axis 2| which is spaced from the shaft axis at all points; I A track is mounted on and disposed circumferentially of the driven shaft 2. This track is mounted on the driving disks 3, and is in-;the nature of matched track sections 22 suitably-,se-, cured to opposing faces of the driving disks and along the inside of which the rollers l8 are adapted to ride. Another track section 23 is also provided on the inner face of each outer driving disk, on the outer side of which-the inner rollers l9 are adapted to ride. The track sections 23 are provided with a recessed 'periph-' eral portion 24 in order to clear the rollers Ill.

The generalshape of the preferred track is shown in Figure 1, and it is to be noted that there are four operating portions; one for the intake stroke, another for the compression stroke,

another for the firing stroke and still another for the exhaust stroke. The design of the track and the arrangement of the cylinders and pistons is such that each of the four pistonsis operating in a different stroke and on a different operating portion of the track at a given time. In the set-up shown in Figure 1 it happens that the piston of cylinder 8 is about to begin its intake stroke, the piston of cylinder 4 is about to begin its compression stroke, the piston of cylinder 1 is about to begin the firing stroke, and the piston of cylinder 6 is about to begin its exhaust stroke; the shaft 2 being rotated in a clockwise direction. Suitable counterweights 25 are mounted on the driving d sks 3. in der to balance the system,

It is to be noted that during the compression, firing and exhaust strokes the track engaging elements or rollers I8 are driving against the outer track sections 22, and that during the intake stroke the piston is moved by the action of the track engaging element'or. roller I9bearing against the inner track sections 23. This ac- .counts for the double construction as indicated 'by the pairs of rollers I8 and the lighter construction as indicated by the single roller l9.

Animportant feature of the mechanism resides in the fact that the track engaging elements move in a path along the axis 2| which is spaced from the shaft axis at all points. By this arrangement the reciprocating motion of the piston :is translated into a rotary motion of the shaft 2 without involving the usual crank shaft dead centers, and the energy available at the piston is applied to the shaft as a torque acting with a substantially constant lever arm; viz., the force of the. piston acts along the line 2| which is fixed with respect to the shaft axis so that the perpendicular distance between the line 2| and the shaft axis is constant. 7

The cylinder heads 26 have the usual spring. pressed intake and exhaust valves 21, and in my machine are actuated by suitable push rods 28 operated by cams 29 mounted directly on the shaft 2 being driven. a This is possible because the four cycles are completed in one revolution of; the shaft 2, and there is consequently no need of a cam shaft operating at halfspeed as required in the ordinary four cycle engine.

By the mechanism shown in Figure, 1 it will be observed that power is being applied to the driven shaft '2 throughout its entire revolution. The firing strokes of the respective cylinders fol- IOW'ID. succession, each operating during 90 degrees of;rotation of the shaft 2. In other words, the operation of the engine approaches that of a constant torque motor. It is thus seen that the four cylinders in this design will give the the same number of power impulses as any ordinary eight cylinder four cycle motor of the present design. One of the advantages of my engine however is that the design leads to a compact arrangement and light weight; these features being particularly desirable in airplane work.

. .Another important feature of this particular design of my engine is the increased piston speed with respect to the crank shaft speed. In the present type of crank shaft motors, where the four cycles are completed in two revolutions of the crank shaft, the piston speeds are definitely limited to a point less than the speed limits of the. expanding gases. This limitation comes in because of the fact that present crank shafts will not function properly above certain speeds. If thesespeeds are. exceeded serious balancing and mechanical troubles arise. In the engine of my invention the piston speeds are materially increased without increasing the speed of the shaft being driven. Furthermore, the straight shaft eliminates many of the balancing troubles inherent in the present type of crank shaft construction. This furthers the possibilities of still higher piston speeds.

A- further advantage of my design results from separating the crosshead and its guide from the hot portionof thecylinder, as compared with ordinary designs in which the piston per se functions as the crosshead. This leads to an increased oil efliciency and reduced friction. Thus,'the limitations imposed on piston speeds by cylinder resistance in present designs is not as .chamber at thebeglnnlng o f zcompression iis 3.069 incheslong and at thc end of compression great inj.}the engine! of my invention; Furthermore the separation oflthecrosshead from the piston it possible "to hood the crosshecd and guide with oiL'and "at'thcsame time avoid all pumping by' the piston rings into the combustion chambert I v f i When the energy available at the piston is applied. to shaft as altorqueiacting with a constant lever arm, the power is not only increased, but the detonation knocks. inherent'in present designs are largely eliminated. This latter is true because in idly-mechanism the maximum lever arm is presented at the time of the explosion, and the piston does not have to drive against a dead centerat this time as, in the vordinary motor. My" mechanism also eliminates piston slap, because the piston is rigid on the end of a piston rod which is parallel to the axis of the cylinder at all times.

" The relation between thetrack; the several ,7 track engaging elements andthe pistonsat the beginningof the various cycles is best illustrated in Figures 3' to 6; InF'igure 3 the piston of cylinder 4 is ready for its intake stroke, the piston of cylinder fl is readyior its compression stroke, and the piston of cylinder 6is ready for its firing stroke, while the piston of cylinder 8 is ready for its exh'aus'tstroke; rotation of .the shaft 2 being clockwise. Figure 4 shows the shaft and track turned through degrees; with the piston of cylinder 4 now ready for its compression stroke, the. piston of cylinder! ready for its firing stroke, the piston of cylinder 6 ready for its exhaust stroke and the piston of cylinder 8 ready for its intake'str'oke. l

Figure 5 shows the shaft and track turned through anotherBO degrees; with the piston of cylinder 4 ready for its firing stroke, the piston of cylinder 1 ready for its exhaust stroke,'the piston of cylinder 6 readyfor its intake stroke and the piston ofcylinder ,8 ready for its compression stroke. Figure 6 showsitheshaft and track turned through'another 90 degrees; with the piston of cylinder 4ready forits exhaust stroke, the piston of cylinder] ready for its intake stroke, the 'piston of cylinder, 6 ready for its compression stroke and the pistoncr cylinder 8 ready for its 'nrmgstrok After the shaft and track has turned through the last 90 degrees of the revolutionthe track and pistons will be in the position shown in fig} ure' 3, and ready to repeat these'ries or cycles, It wlllbe notedthat the several strokes in'the four cycles of a given piston are of different lengths, and that theafiring, stroke is materially longer than the'compres'sion stroke.v v This[gives an expansion ratio greater than the compression ratio, In'the design showmtaken merely for the purposes of illustration, thetraek was laid out toaccord'with strokes of jthe'lcfollowing lengths: 4 Inches Intake "stroke 3.024 Compression'stroke---;, l 2,592 Firing stroke 5.076 Exhaust stroke ;5.508

The clearance between the piston and the'cylinder head' at the innermost limit; ofthe piston movement was 0.45 inches Figure 9 shows dingrammatically ,the above relation. Here it will be observed that theinner limit of the piston at the end of the compression stroke is spaced .432 inches from the inner limit of the piston at the beginning of the intakestroke. Thus, the

is :17! inches long, which gives a compression ration! 3.069 divided by .477 or 6.433 to Lit-The,"

chamber at the beginning or the firing stroke is thus .47! inches long while at the-end. of expan-' sion is 5.553 inches long, which gives an expansiOii ration! 5.553 divided by'A'l'? 0r 1l.'751;to l. a "The 'increaaed'expansionratio results in a-nlore complete expansion of the'gases during the power stroke, and permits the'conversion of the lower pressures toward" the end of the expansion into useful workyinstead of being exhausted into the muiiicr' as in present' practice. This not only leads tomore power and increased emciency and econommbut alsothe exhaust gases will be at lower pressure and temperature. The lower pressures'reduce the noise of exhaust, and the re- Ill duced temperature will largely eliminate the -troubles now encountered with exhaust valves.

-It is to be noted that the exhaust stroke of 5.508 inches brings the piston back'to the clear-- tion chamber, carbon deposit is reduced.

Because. of the variation that can be effected between the lengths of strokes, the compression ratio can be ii'icreasedabove ordinary practice;

and-this will result in an increased output" or 7 energy from. the same amountoi fuel, andwill also permit a decrease in-the difierencein length between the powerand exhaust strokes in" my engine and at thesame time scavenge. the cylinder Considering the more'completescavengering and the increase possible in compression in the engineoi my invention it is easily possbleto get as much power out of my short intake stroke of 3.024 inches as in a present type motor with an intake strokcin the order of 5.508 inches both engines having thesame length of power stroke.

The design of the track is such that th'e several operating portions thereof willaccord with slow starting and stopping movements for; the piston at the beglzmi'ngan'd end of each stroke.

In 'ordinary internal combustion The operating portions of the track through the idle strokes are preferably uniformly accelerating forhali' their length and uniformlydecelerating for the other hall; while the operating portion in the poweristroke is preferably a'nearly constant speed curve, being uniformly accelerating.

rapid a start to the piston as is possible and still in keeping with silent operation. The; rapid movement of the piston into its nearly constant speed during this stroke operates toabsorb J as rived from combustion than is possible in the or useful work a larger portion of the 'energysde' dinary motor. Thisfeature conserves a-portion ofthe energy which'is ordinarily converted. into' radiating heat. Asa result, the engineembody-l ing my invention is more efficienti in thisrespect andradiat'es less heat ,to-the cooling system. The method of laying-out the track-is illustrated in Figure8; which shows theoperating portion of the track associated with'theafiring stroke.- This track portion is laid out toaccord with a firing stroke 5.076 inches long,:and with the cen, terline or, axis of motion z'l of the track engaging. element spaced inches from the gaxisjof the'shaft 2; this 4inches being measured onthe perpendicularfrom the line 2 Lto the shaft axis-wv Referring to Figure 8, the point 0 representsthe axis .of ,thershait 2. Using Oas a:. center a quad: rant AOG of acircle is describedona 4 inch .radius starting from a point A verticallvabove'the point 0; This quadrant is then divided into- 1-8 equal sectors; viz., 18 radii are drawn.5 degrees apart." Tangents are then drawn to the circle at the intersection of the radii these tangents ex: tending upwardly and to the, right, as shown.. ,:A tangent is also drawnto the circle at the .pointA; this tangent extending to the right-toward point C. A point -B is then located-on the, line AC Drefe erably 1 inches to the right of point A. 1" 1 From B toward 0 a distance is then laidiofi 5.076 inches long; this being the lengthyof the firing stroke. Letv thepoint Qindicate the end of this distance, so that the lineBG represents the length of the firing stroke. The'line BCis then divided into 18 parts, corresponding to; the 18 divisions of the circlequadrant; The divisions of the line BC will Varydepending upon-g the motion characterizing thepiston... For the, firing stroke, as has already been mentioned, thisrais preferably uniformly accelerated-at the beginning, then substantially constant forthegreater portion of the stroke, and finally uniformly decelerating near the end; .For examp1e;"the divisions chosen in the design shown herein are as follows; the "divisions or portions of length being I 7 given in inches:

, After these divisionshave been laid out along the line BC, laying off fronrB toward C .andin the above order, as shown in-Figure 8, an. arc

with a radius from O to the firsttdivision at.:=the right of B is scribed to'intersect the first tangent lineto the left of .A. This locates the second point along the curve which is to define the center line of the track; the first point'located'of course-being the'point B. z'Next' an aro'from the point 0 to the second division to theright of B isscribed to intersect the second tangent-line to the left of A. This locates'the third point on the curve. Y

Other points are similarly located on the tangents untili finally the arc 0C haszbeen scribed to intersectcthe tangent line from thexlast radius of. the quadrant; This completes the. center line curve of the track for the firing stroke. Inorder to locate the edge portions of the track; circles are described about the located points as centers; theseicircles having-radii equal to the radius of thetrack engaging rollers. Lines drawntan gent to the outer edges of these .circles define the inner'edges of the track; 1 1 1 The other operating portionsof the tr'ackare developed: in a; manner similar'to that for, ,the

firing stroke, above described. .'In' thecaseuof the-other or idle strokesv however :the motion of the piston is preferably uniformly accelerating for halfofits movement. and then uniformly de-.

celerating for the otherhalf. ;For example, take the next operatinggportion of'the. trackiwhich.

- happens to be'that portion'operating through the exhaust strokes Beginning at the pointC a dis+ tance is laid-ofi toward A 5.508 incheslong,-or the n Theifollowing gives the 18 divisions inches;

These portions' are laid out on the tangents to thef18 radii in the next quadrant vGfOI-l of the circle, as was done in developing the previous track portion.

The next succeedingoperating portion of the track, which is for the intake stroke; is laid out in a similar manner. Inthis case .thelength of the intakestroke (3.024 inches) is laid'oif toward C'from .thejpoint D, and willterminate at some point, say at E. The line DE is then divided for uniformly accelerating and uniformly decelerat: ing motion, as was the exhaust stroke. The divi siohs'ini inches work, out as follows:

The divisions in inches work out as follows:

These.divisions are laid on on the tangents to a roller 32 engaging a track section 3|]. The oth- 7 er end of the crosshead shaft preferably carries a crank 33 on which is journaled a roller 34 engaging one side of the othertrack section. Disposed oppositely of the crank 33 is another crank arm 36 fixed on the crosshead. This latter crank arm carries a roller 37 engaging the side of the track section 3i! opposite the roller 34. In this case the piston in the compression, power and exhaust strokes drives against both track sections through the rollers 32 and34, and on the intake stroke is moved'by the action of the roller 3?.

While I have chosen to show, as the preferred form of my invention, a motor in which the four cycles are completed in one revolution of the shaft being driven, it is understood that the track may be designed to complete the four cycles in two revolutions of the crank shaft; In this case the strokes would beof substantially equal length, as in ordinary practice. The advantage over the present type of crank shaftinotor however would be the elimination of .crank shaft dead centers. tion of the preferred form, in which the four cycles are completed in one revolution of the shaft being driven, would be to use segments of' different size instead'of equal quadrants in the development of the track. Thus by using a 122 degree segment for the exhaust, a 113 degree segment for the firing stroke, a 67 degree segment for the intake stroke and a 58 degree seg- It is also obvious that a modifica-' ment for the compressionstroke, the developed track will accord with strokes of equal length.

In conclusion, it is pointed out that the engine embodying my invention as compared with the ordinary internal combustion motor is of simpler and more compact design with fewer working parts; is freer of mechanical troubles and is capable of and able to maintain a better mechanical balance; and operates with less power loss in exhaust and heat radiation. At the same time, greater power can befsecured in my engine with less weight, less vibration and less noise'of operation. Even-with the higher pressures that are possible, the long expansion stroke will operate to expand the gases to close to atmospheric pressure, and even at open throt-- tle the engine will require very little mufiling.

Since the power from'the pistons in the preferred engine embodying my invention is applied to the driven shaft throughout its entire revolution, the motor approaches thatof a constant torque engine; in other words, the power'is applied more as a constant stream than asa series of jerks. This feature combined with the nature of the disk drive, which itself acts as a -fiy wheel without an increase in weight over present crank shafts per se, makes the engine particularly desirable in airplane work.

I claim:

An engine comprising a shaft, a pair of spaced disks mounted on the shaft, a matched pair of endless track sections mounted on thedisks, an elongated casting disposed between the disks and alongside the shaft and having a longitudinal bore, one end of said bore providing a combustion cylinder, a piston slidable in the cylinder end of the bore, a circular crosshead connected with a the piston and slidable in the other end of the bore, said casting having longitudinally extending and oppositely disposed slots adjacent the latter end, a pin in the crosshead projecting through the slots,and rollers on the pin engaging said track sections.

- WILLIAM H. STONE.

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