US1881027A - Reciprocating engine - Google Patents

Description

Oct. 4, 1932. r w. H. MANNING 1,881,027

RECIPROCATING ENGINE Filed Aug. 2, 1929 gmentoo Patented Oct. 4, 1932 PATENT OFFICE WILLIAM H. MANNING, OF PONTIAC, MICHIGAN RECIPROCATING ENGINE Application filed August 2, 1929. Serial No. 382,968.

This invention relates to reciprocating engines, particularly engines of internal com bustion type having multiple cylinders arranged in one or more rows longitudinal of the crank shaft.

Among the objects to be achieved are substantial freedom from vibration due to inertia torque and piston unbalance; even torque or even application of the turning efforts of the several pistons to the'engine shaft; compactness in multiple cylinder engines having 'one or more straight rows of cylinders as compared with eveness of turning effort; equal apportionment of carburetted mixture to the several cylinders, and others inherent in the construction to be here inafter described in detail.

The invention comprises an engine having 4 an engine shaft provided with an odd number of throws, no two of which lie in the same plane, one or more pistons connected to each throw and one or more rows of cylinders in which the pistons reciprocate. It also comprises parts and details of construction as hereinafter described. 4

1 One embodimentofthe invention is illustrated in theaccompanying drawing wherein like parts are indicated by like reference characters 7 In saiddrawing:

Fig. 1 is a perspective of a crank shaft and connected pistons made in accordance with the invention, I I

Fig. 2 is a section on the line 2P2 of Fig. 1 viewed from the rear toward the front,

i Fig. 3 is a perspective of an engine block associated with intake and exhaust inanifolds, and v Fig. 4 is a diagrammatic showing of a V14 engine embodying the invention;

Fig. 3 depicts anautomobile engine cyl inder casting provided with seven cylinder bores inline, numbered 11, 12, 13, 14, 15, 16

These cylinder and 17 from front to rear. bores are illustrated as formed. in. a monobloc casting although they maybe formed otherwise according to known practice's. Intake manifold 20 extends fore and aft of the engine from a central riser disposed at one side diverges into U-shaped branches 20/ and 207' at front and rear respectively each branch terminating at opposite ends in delive ports. The front end of branch 20/'' delivers to twin intake ports 21 and 22 in communication with cylinders 11 and 12, respectively,

while the rear end of said branch delivers to twin intake ports 23 and 24 in communication with cylinders 13 and 14 respectively. The front end of the rear branch 201' delivers to intake port 25, in communication with cylinder 15 and its rear end delivers to twin ports 26 and 27, in communication with cylinders 16 and 17 respectively.

An exhaust manifold 30 communicating with exhaust pipe 30a extends also fore and aft of the cylinder casting in proximity to the intake manifold, and is adapted to heat the mixture in the intake riser and manifold according to usual practice. tending inward toward the block from the exhaust manifold terminate, respectively, with exhaust port 31 for cylinder 11, twin exhaust ports 32 and 33 for cylinders 12 and 13; twin exhaust ports 34 and 35 for cylinders 14 and 15, and exhaust ports 36 and 37 for cylinders 16 and 17.

The engine shaft is indicated as an entirety by numeral 40. This shaft is illustrated as having four bearing journals numbered 44, 43, 42 and 41 from rear to front. At the rear end is attached the customary fly wheel indicated by dotted linesat 45 and at the front atiming gear 46 as usual. The shaft 40 has seven throws illustrated as eccentrics or crank pins carried between crank arms. These eccentrics or crank pins are numbered in the drawing from rear to front, 7 6, 5, 4, 3, 2 and 1. The several eccentrics or pins are angularly displaced about the axis of the shaft in such manner that the radial planes connecting the eccentric or pin centers with the'axis of the shaft will divide a circumference struck from said axis into seven preferably equal arcs (360/7).

Upon reference to Figs. 1 and 2 it will be seen, starting from eccentric or pin 1, that the eccentrics or pins are there shown spaced successively 360 /7 in the order 1, 7, 3, 5, 2, 6, 4 or the reverse,i. e., pin 7 is angularly Branches ex- 50, 40, 3c, 20, 10. j r I Inspection of Fig. 1 and Fig. 2 will show spaced 51 3/7 from 1; 3 1s spaced 51 3/7 from 7, and so on. With this arrangement it is apparent that the shaft may be easily constructed to be in static balance and that no two i 5 longitudinally adjacent throws will pass in succession through the same radial plane including the shaft axis when the shaft is rotated:

In order to place the described shaft in balancing.

"e" seven throw shaft illustrated'is subjectto avariable inertia couple of relatively small magnitude tending to rock the engine about a transverse axis.

ends, respectively,'the magnitude of this coupIe may be materially reduced. Viewing the crank shaft from the rear (theleft of Fig. 1) 9 the" center of the mass of counterweight 48 7 should be about 115 measured in. a clockwise sense from the radial plane passing through the center of eccentric pin 1, and the center of mass of counterweight 49 should be 5 about measured inthe opposite sense from the same radial plane. The counterweights needed. are'small and'may b forged integral with the shaft. I

- Fig. 1' showsthe several'pistons and connecting rods of a straight seven cylinder en-- gine in their relationto the seven throw engine shaft. Thepistons are indicated from rear to front end by reference characters 7 612,519, 4;), 8p, 2p,--1p; the corresponding connectingrods are similarly identified by 7 c,

that no two pistons and connecting rods reach either end of their several reciprocating of the forces developed in a running engine and connecting rods exert substantially no unbalanced inertiatorque tending to rock the engine about a'longitudinal axis and no un-' balanced primary or secondaryfree inertia forces tending to oscillate or vibrate the engine in planes parallel with the longitudinal cOunterWeights481and 49 (in an engine having a crankshaft 26 long-2% bore and I 4L" stroke thesecounterweights are about 4.6

i 7 ounces 'inweight). If any objectionable vi-.

dynamic balance the mass of each of the in By placing small counterweighting masses 48 and {9 at oppositesides of'the'shaft at the front and rear lIlOVGHlQIltS at thesame time. 4 Computation of this construction indicate that the pistons l, :5. 2,

axis. The inertia couple referred to tending to rock the engine about a transverse axisf may be overcome in part by said two light brationsdue to said couple should occur they may be'insulated from the chassis frame by known types of engine insulating mounts. The lightness and stiffness of the shaft gives it a natural frequency if torsional vibration so high that its period of objectionable res-' onance'with respect to the frequency of the piston thrusts will be above the driving range of the engine. The turning efforts of the pistons due to gas pressure will be so evenly distributed as to assuresmoothness of power delivery. The crank shaft may be easily manufactured by forging a flat blank and giving maximum twists of approximately 7 2 0 In a four strokecycle, straight seven cylinder engine havingthe eccentric pinsof the shaft disposed as described the firing order is counterclockwise viewed fromrear to front. Reference to Fig. 3 -shows that 'manifolding for this" arrangementand firing order isadvantageo'us, because no two cylinders draw combustible mixture from the same delivery.

port or ,valve pocket or same portion of the manifold adjacent the same delivery port in succession. For example, cylinder 11 draws from twin port 21at-the front end ofthe forward branch of nianifold'20; the next cylinder to fire, cylinder 13, draws from twin 1,53, 2,4, 7, 5,6, ifithe crank shaft rotates port 23 at, the rear end of saidforward branch; the next cylinder to fire is cylinder 12, which-draws from twin port 22 at the front end of the forward manifold branch,

and the cylinder 14c, firing next, draws from.

port 2& at the back end and so it will be seen the remaining cylinders firing in succession draw mixture alternately from the rear and front ends of the rear branch of the manifold. There will be, accordingly, no impoverishment of fuel in any one cylinder due to thefact that the cylinder which fired immediately preceding took its charge from the same portion of the manifold.

A seven cylinder engine utilizing the described seven throw engine shaft is well adapted to operate as atwo stroke cycleengine, giving seven turning impulsesduring each revolution. The fir ng order for a .counterclockwise running two stroke cycle 7 engine viewed from rear to frontwould be 1,- 7,

" Crank shafts of thetype illustratedjhaving an odd number ofthrows no two of which lie in a common plane are also well adapted for engines having a plur ality of'rowsof cylinders arranged inplanesradiating fromthe crank shaft axis. The cylinders shown in.

Fig.3,for example may be duplicated, one

rovvbeing separated angularly from the other "102 6/ as indicated by the angleycru in Fig. 2 for'an ,engineoperating on the four stroke,

cycle in case-even firing intervals are desired;

The connecting'rods ofjcylinders whose axes areonthe-sametransverse plane would be connected to the same crank pin or eccentric as is usual in V-engines.

As required by the statutes, I have explained the principle of my invention and have specifically described and illustrated one preferred embodiment thereof. I do not, however, intend to be limited in patent protection to the precise form of the exemplary embodiment disclosed, but refer to the claims as defining the scope thereof.

I claim:

1. A reciprocating engine provided with 1 cylinders, pistons and a crank shaft having 7 seven throws no two of which lie in the same radial plane, said throws being angularly disposed from one end to the other of the shaft in such order that if the shaft be rotated the throws will pass through a radial plane in cluding the shaft axis in the order 1,7, 3, 5, 2, 6, 4, or the reverse according to the sense of rotation.

2. A four-stroke cycle internal combustion engine having seven cylinders arranged in tandem and suitable inlet and outlet ports; a piston in each cylinder; an engine shaft having seven throws no two of which lie in the same radial plane, and angularly disposed from one end to the other of the shaft in such order that if the shaft be rotated the throws will pass through a radial plane including the shaft axis in the order 1, 7, 3, 5, 2,

v 6, 4 or the reverse, said throws reaching firing verse, in accordance with the sense of rotation; rods connecting the several pistons with the several throws; means for conducting exhaust gases from the outlet ports; an intake .manifold communicating with all cylinder inlet ports by delivery ports so disposed that no two cylinders firing in succession draw mixture from the intake manifold adjacent the same delivery port.

3. A four stroke cycle internal combustion engine having seven cylinders arranged in tandem and suitable inlet and outlet ports, a piston in each cylinder and suitable connecting rods, an engine shaft having seven throws angularly disposed from one end to the other in such order that if the shaft be rotated the throws will pass through a radial plane including the shaft axis in the order 1, 7, 3, 5, 2, 6, 4, or the reverse, according to the sense of rotation, reaching firing position in the order 1, 3, 2, 4, 7 5, 6, or the reverse rods connecting the several pistons with the several throws; an intake manifold having four delivery ports, three pairs of adjacent cylinders having their inlet ports twinned, and communieating each with a single delivery port of the manifold, and one cylinder having an individual inlet communicating solely with the remaining delivery port in the manifold; the arrangement providing that no two cylinders firing in succession draw mixture from the same delivery port of the manifold.

4. A combination as defined in claim 3 in which the intake manifold has a main section extending fore and aft of the engine on opposite sides of a central riser, each end of said main section connecting with U-shaped branches, each end of one branch delivering to twin cylinder inlets; one end of the other branch delivering to twin inlets and the other end of the last named branch delivering to an individual cylinder inlet.

5. An internal combustion engine having an odd number of cylinders, pistons, and connecting rods arranged in tandem, a crankshaft having a corresponding odd number of throws, no two of which are disposed in the succession, means for conducting combustible mixture to the inlet ports, said means having delivery ports arranged with respect to the inlet ports so that no two cylinders firing in succession draw mixture from the manifold adjacent the same delivery port.

In testimony whereof I affix my signature.

WM. H. MANNING.

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