US3866581A

US3866581A - Opposed piston engine

Info

Publication number: US3866581A
Application number: US395751A
Authority: US
Inventors: William B Herbert
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-09-10
Filing date: 1973-09-10
Publication date: 1975-02-18
Anticipated expiration: 1992-02-18

Abstract

A two-stroke opposed piston engine is provided embodying a single crankshaft which is rotated by the conjoint action of opposed pistons acting through connecting rods and eccentrics on the crankshaft. The crankshaft and its eccentrics are relatively small as compared with those used in conventional internal combustion engines, and are so located in this engine that the forces of compression and the resultant torque are confined within a central area, and the need for a cylinder block of large mass or weight is eliminated. The engine does not require fans or blowers for scavenging the burned gases from the engine. In a modification of the engine, novel means for injecting fuel, a cooling fluid, or a mixture of these into the combustion chamber is employed.

Description

iclttite States Patent 1 Herbert OPPOSED PISTON ENGINE William B. Herbert, 111 Yantacow Brook Rd., Upper Montclair, NJ. 07043 ;l2] Filed: Sept. 10, 1973 til] Appl. No.: 395,751

[76] Inventor:

[ Feb. 18., 1975 3,077,188 2/1963 Herrmann 123/74 A X Primary Examiner-Wendell E. Burns Attorney, Agent, or Firmlsler and Ornstein ABSTRACT A two-stroke opposed piston engine is provided embodying a single crankshaft which is rotated by the conjoint action of opposed pistons acting through connecting rods and eccentrics on the crankshaft. The crankshaft and its eccentrics are relatively small as compared with those used in conventional internal combustion engines, and are so located in this engine that the forces of compression and the resultant torque are confined within a central area, and the need for a cylinder block of large mass or weight is eliminated. The engine does not require fans or blowers for scavenging the burned gases from the engine. In a modification of the engine, novel means for injecting fuel, a cooling fluid, or a mixture of these into the combustion chamber is employed.

5 Claims, 12 Drawing Figures PAIENTEU EM Y 3,866.581

' SHEET 10F 6 4 26b 45 I9 4| 4e 42 56 arm 55 I4 260 fig, 4

PATENTEU 1 3,866,581 SHEET 6 OF 6 OPPOSED PISTON ENGINE This invention relates generally to internal combustion engines, which may be of the diesel or petrol (gasoline) type, but has reference more particularly to twostroke engines.

In two-stroke engines, two strokes of the engine are required to perform a full cycle of operations, that is to say, changing the contents of the cylinder and effecting the combustion.

In conventional engines of the two stroke type, the forces of compression and the resultant torque transmitted to the crankshaft by connecting rods are not confined within a central area, so that it is necessary to provide a large cylinder block for such engines, thereby adding greatly to the mass and weight of the engine.

Another objection to such engines is that all or most of the inertial forces which aregenerated during the operation of the engine are transmitted in a single or generally single direction, thereby contributing to the wear and tear on the engine, and increasing the vibra tion of the engine when in operation.

Other objections to such engines is .that they usually require compressors or blowers to scavenge the burned gases from the engine, thereby adding materially to the cost of the engine.

The present invention has, as its primary object, the provision of an opposed piston two-stroke engine of high efficiency which has embodied therein a single crankshaft, instead of multiple crankshafts, gears, levers, etc., which are usually associated with the use of opposed pistons.

Another object of the invention is to provide an opposed piston enting of the character described, in which the piston speeds are low in comparison with those of conventional engines, and in which the crankshafts are smaller than in conventional engines, that is to say, the crankshaft throws are smaller.

Another object of the invention is to provide anopposed piston two-stroke engine of the character described, in which the forces of compression and the resultant torque transmitted to the shaft by the connecting rods are confined within a central area, and the need for a cylinder block of large mass or weight is eliminated.

Another object of the invention is to provide an engine of the character described, in which there is provided for each movement of each component part, an equal movement in the opposite direction, whereby a complete offsetting or balancing of any and all inertial forces is effected, with the single exception of the rotating torque, thereby reducing wear and tear of the engine, and reducing the vibration of the engine when in operation.

A further object of the invention is to provide an engine of the character described, in which fans or other scavenging means are not'required to scavenge the burned gases from the engine, and the. overall cost of the engine is thereby appreciably lowered.

A still further object of the invention is to provide an engine of the character described,,embodying novel I apparent during the course of the following description.

In the accompanying drawings forming a part of this specification, and in which like numerals are employed to designate like parts throughout the same,

FIG. 1 is a top plan view of an opposed piston engine embodying the invention;

FIG. 2 is a front elevational view of the engine of FIG. 1;

FIG. 3 is an end elevational view of the engine, as viewed from the right end of FIG. 2;

FIG. 4 is a cross-sectional view, taken on the line 4-4 of FIG. 2;

FIG. 5 is a cross-sectional view, taken on the line 55 of FIG. 1;

FIG. 6 is a cross-sectional view, taken on the line 6-6 of FIG. 2;

FIG. 7 is a cross-sectional view, taken on the line 7 7 of FIG. 1;

FIG. 8 is a fragmentary cross-sectional view of a portion of FIG. 5, but with the pistons in extended position;

FIG. 9 is a fragmentary cross-sectional view, on a greatly enlarged scale, of one of the check valves shown in FIG. 5;

FIG. 10 is a view similar to FIG. 1, but showing a modification of the engine, in which fuel, or water or other suitable fluid for lowering the combustion temperature and reducing nitrogent emissions may be injected into the combustion chambers 1419;

FIG. 11 is a cross-sectional view, taken on the line ll-ll of FIG. 10, and

FIG. 12 is a cross-sectional view. taken on the line l2-l2 of FIG. 10.

Referring more particularly to FIGS. 1 to 9 of the drawings, reference numerals 1(1 and 11 designate a pair of housings, which are secured in opposed rela tionship to each other, as best shown in FIGS. 1 and 2.

The housing 10 is provided with a cylindrical extension 12, while the housing 11 is provided with a cylindrical extension 13, which is aligned axially with the extension 12, but extends in a direction opposite to that of the extension 12.

The housing 10 is hollowed out to provide a combustion chamber 14, defined by top and

bottom walls

15 and 16 respectively, and end walls. 17 and 18, which in terconnect the

walls

15 and 16.

The housing 11 is similarly hollowed out to provide a combustion chamber 19, defined by top and

bottom walls

20 and 21 respectively, and

end walls

22 and 23 which interconnect the

walls

20 and 21.

The

chambers

14 and 19 coact to form a single combustion chamber in the central portion of the engine.

Secured to the housings l0 and 11, as by means of bolts 24, is a bearing 25 which extends upwardly'into the space between the housings, and has journalled for rotation therein a crankshaft 26, the axis of which intersects the axes of the

cylindrical extensions

12 and 13. The crankshaft 26 is provided at opposite sides of the housings l0 and 11 with

eccentrics

26a, 26b, 26c and 26a.

The cylindrical extension 12 has secured to its outer end, a second cylinder 27 of enlarged diameter, which is closed at its outer end by a cover plate 29, which is secured to the cylinder 27. The plate 29 is provided with a reed valve 30.

The cylindrical extension 13 has secured to its outer end a second cylinder 31 of enlarged diameter, which is closed at its outer end by a cover plate 33, which is secured to the cylinder 31. The plate 33 is provided with a reed valve 34.

The cylindrical extension 12 has mounted therein, for sliding reciprocal movement, a piston 35, having an enlarged head 35a which is slidable in the cylinder 27.

The cylindrical extension 13 has mounted therein, for sliding reciprocal movement, a piston 37 having an enlarged head 37a which is slidable in the cylinder 31.

The piston 35 is provided with a-piston pin38 which extends diametricallythrough the piston, with the ends of the pin passing through slots 39 and 40in the sides of the cylindrical extension 12.

The piston 37 is provided with a piston pin 41 which extends diametrically through the piston, with the ends of the pin passing through

slots

41 and 43 in the sides of the cylindrical extension 13.

One end of the piston pin 38 is pivotally connected to. one end of a connecting rod or crank 44 provided at its opposite end with a circular opening 45 in which the eccentric 26b is mounted or disposed.

The other end of the piston pin 38 is pivotally connected to one end of a connecting rod or crank 46 provided at its opposite end with a circular opening 47 in which the eccentric 260 is mounted or disposed.

One end of the piston pin 41 is pivotally connected to one end of a connecting rod or crank 48 provided at its'opposite end with a circular opening 49 in which the eccentric 26a is mounted or disposed.

The other end of the piston 41 is pivotally connected to one end of a connecting rod or crank 50 provided at its opposite end with a circular opening 51, in which the eccentric 26d is mounted or disposed.

The crankshaft 26 has keyed to one end thereof a flywheel 52 The portion of the cylinder 27 to the left of the piston head 35a, as viewed in FIGS. 4, and 8, may be considered as a compression intake chamber 53, while the portion ofthe cylinder 27 to the right of the piston head 35a, as viewed in FIGS. 4, 5 and 8, may be considered as a scavenging and air'super charging chamber 54.

Similarly, the portion of the cylinder 31 to the right of the piston head 37a, as viewed in FIGS. 4 and 5, may be considered as a compression intake chamber 55, while the portion of the cylinder 31 to the left of the piston head 37a, as viewed in FIGS. 4 and 5, may be considered as a scavenging and air super charging chamber 56. I

As best seen in FIGS. 5, 6 and 9, the cylindrical extension 13 is provided with a passageway 57, which is normally closed at its right end by a check valve comprising a ball 58, a coil spring 59, and a retainer cap 60, which is screwed into the housing 10, and has circumferentially-spaced openings 61 adapted to communicate the combustion chamber 14 with the passageway 57 when the valve is open.

The passageway 57 communicates at its left end with a passageway 62 in the cylinder 27, which is in axial alignment with the passageway 57. The head 35a of the piston 35 is provided with a passageway 63 which is normally closed by a check valve generally designated by numeral 64, which is similar in construction to the check valve 58-59-60.

An intake port or passageway 65 extends from the passageway 59 to the interior of the cylindrical extension 12.

An exhuast port 66 is provided, which extends from the interior of the cylindrical extension 12 to the atmosphere.

The cylindrical extension 13 is provided with a passageway 67, which is normally closed at its left end by a check valve generally designated by numeral 68, which is similar in all respects to the check valve 58-59-60. 7

The passageway 67 communicates at its right end with a passageway 69 in the cylinder 31, which is in axial alignment with the passageway 67. The head 37a of the piston 37 is provided with a passageway 70 which is normally closed by a check valve generally designated by numeral 71 which is similar in all respects to the check valve 58-59-60.

An intake port or passageway 72 extends from the passageway 67 to the interior of the cylindrical extension 13.

An exhaust port 73 is provided which extends from the interior of the cylindrical extension 13 to the atmosphere.

The reed valve 30, as best seen in FIGS. 1, 2, 4 and 5, comprises a circular disk 74, which is secured to the cover plate 29 and is provided with circumferentiallyspaced openings 75, which communicate with a bore 76 in the cover plate, which, in turn, is provided with a valve seat 77. The valve is normally closed by a valve 78 having a stem 79 which passes axially through the disk 74 and terminates in a head 80. A coil spring 81 is interposed between the head and disk 74, and bithe valve to closed position.

The reed valve 34 is of the same construction as the reed valve 30, and need not, therefore. be described in detail.

Passageways

82, 83, 84 and 85 extend through the housings 10'and 11, and are provided for the purpose of circulating a cooling fluid therethrough.

Passageways 86 are also provided in the

housings

10 and 11 for the passage therethrough of bolts (not shown), whereby the housings may be secured to each other by means of nuts and bolts.

An opening 87 is also provided which communicates with the combustion chamber 14-19, and serves for the introduction of fuel, when the engine is used as a diesel engine, or for a spark plug, when the engine is used as a gasoline or spark ignition engine, in which latter case, a second opening, not shown, may be used for the introduction of fuel into the combustion chamber 14-19.

The bearing 25 may be provided with passageways 88 for the purpose of circulating a cooling fluid through the bearing.

The operation of the engine may now be briefly described.

The shaft 26 is shown in FIGS. 1, 2, 3, 4, 5 and 6, as at what may be termed the top dead center position, a position which corresponds to the top of the piston stroke in a conventional internal combustion engine, and from which continued motion of the engine causes the piston to descend in such a conventional engine.

Rotation of the shaft 26 has brought the

pistons

35 and 37 to such top dead center position, and has simultaneously induced atmospheric air through the

valves

30 and 34 and into the

intake chambers

53 and 55.

At this point, combustion of gases in the combustion chamber 14-19 is effected, so that the pressure of the expanding gases in this chamber is exerted on the inner ends of the

pistons

35 and 37, causing the shaft 26 to rotate 180 beyond the top dead center position, and thereby cause the air charge in

chambers

53 and 55 to be transferred through the

check valves

64 and 71 and into

chambers

54 and 56, which are created by the outward movement of the

pistons

35 and 37, the outermost position of the piston 35 being shown in FIG. 8. Due to the relative sizes of the

chambers

53 and 55, as compared with the

chambers

54 and 56, the air in

chambers

54 and 56 is under compression. When

pistons

35 and 37 have uncovered

inlets

65 and 72 respectively, air from

chambers

54 and 56 enters combustion chamber 14-19 and

cylinders

12 and 13 for scavenging. The pressure of the air in

chambers

54 and 56 is reduced to atmospheric pressure.

Continued rotation of the shaft 26 through another 90 causes the air charges in

chambers

54 and 56 to be compressed, and further rotation of the shaft 26 through another 90, that is to say, back to the top dead center position, will cause super charging of the combustion area 14-19 by the remaining charge of air from the

chambers

54 and 56.

Where the engine is used as a diesel engine, suitable fuel injection is effected through the opening 87, or, if the engine is to be used in the manner of a conventinal gasoline engine, as by a spark plug secured in the opening 87.

The

intake ports

65 and 72, and

exhaust ports

66 and 73 are so located along the

cylindrical extensions

12 and 13, as to be effectively opened and closed by the movement of the

pistons

35 and 37.

The mechanical connection of the

pistons

35 and 37 with the crankshaft 26 is, as described, effected through the piston pins 38 and 41, and connecting

rods

48, 44, 46 and 50,

theslots

39, 40, 42 and 43 in the walls of the

cylindrical extensions

12 and 13 permitting suitable movement to accommodate the stroke of the pistons.

The sequence of operations through two cycles or 360 of rotation of the shaft 26 may be summarized as follows:

From the top dead center, rotation of the shaft 26 through 180, causes power to be applied to the

pistons

35 and 37 by burning gases in the combustion chamber 14-19, driving the pistons outwardly. The connecting

rods

48, 44, 46 and 50, under tension, transmit motion to the

eccentrics

26a, 26b, 26c and 26d, causing the crankshaft 26 to rotate. The outward movement of the

pistons

35 and 37 transfers air from

chambers

53 and 55 through the

check valves

64 and 71 into

chambers

54 and 56, where the air is retained under pressure until the

pistons

35 and 37 have uncovered the

exhaust ports

66 and 73, now uncover

intake ports

64 and 72, allowing air to pass from

chambers

54 and 56 into

cylinders

12 and 13, effecting scavenging, and intake by suction ofair at atmospheric pressure into

chambers

53 and 55, simultaneously with compression in combustion chamber 14-19.

As the

pistons

35 and 37 approach the top dead center position, they simultaneously compress air in the combustion chamber 14-19 and in

chambers

54 and 56, the contents of which ultimately pass through

passages

57 and 67 and

check valves

60 and 68 into combustion chamber 14-19, after fuel injection has been initiated. The secondary compression introduces turbulen ce in the combustion chamber 14-19, to thereby cause more complete combustion.

The engine, as thus described, is a two-cycle engine, in which the necessity for pressurized crankcase blowers or scavenging blowers is eliminated.

The engine may be constructed as described, or with any number of duplicates of such mechanisms.

In the case of multiple cylinder engines, the

cover plates

29 and 33 will serve to close the ends of

chambers

53 and 55, and in the case of'multiple cylinder engines, these cover plates will be of sufficient length to cover all of the cylinders of which the engine is constructed.

The

cover plates

29 and 33 can also serve as mounting surfaces or supports for locating and supporting the engine, and can also serve as a portion of a complete enclosure, which, in this configuration, may be composed ofa total of six flat pieces, i.e., two

cover plates

29 and 33, two end plates (not shown), and top and bottom plates (not shown), which would then, in effect, provide a complete oil-tight enclosure for the operating mechanisms.

The mechanism, as described, can, with slight modification, also serve as an external combustion engine, a fluid power engine, or as a compressor.

Referring to the modification shown in FIGS. 10, 11 and 12, the engine is provided with passageways and 91, which extend through the walls of the cylinders 12-27 and 13-31, parallel to the axes of these cylinders, these passageways extending from the combus tion chamber 14-19 to the

chambers

54 and 56 respectively.

The

passageways

90 and 91 are respectively provided at the ends thereof adjacent the combustion chamber 14-19 with nozzles or jets 92 and. 93.

The

cylinders

12 and 13 are also respectively provided with

inlet ports

94 and 95, which communicate with the

passageways

90 and 91.

The

heads

35a and 37a of the

pistons

35 and 37 have secured therein the ends of

plungers

96 and 97 which extend into the

passageways

90 and 91 and are slidable in these passageways.

When the

pistons

35 and 37 are: at the outer ends of their stroke, as in FIG. 8, fluid from any suitable source (not shown) enters the

ports

94 and 95 and the

passageways

90 and 91. When the pistons return to their top dead center position, this fluid is injected by the

plungers

96 and 97 from the passageways through the nozzles or jets 92 and 93 and into the combustion chamber 14-19.

The fluid injection means, as thus described, may also be employed to inject fuel, a cooling fluid, or a mixture of both, into the combustion chambers.

The nozzles or jets 92 and 93 are of a commercially available type or design which are normally closed and require pressure on the fluid (fuel, coolant or mixture), as by the

plungers

96 and 97, to cause passage of the fluid through the nozzles. Nozzles or jets of this type are described on pages 972 and 973 of Volume 38 of the 1973 Edition of Diesel and Gas Turbine Worldwide Catalog.

It is to be understood that the forms of my invention, herewith shown and described, are to be taken as preferred examples of the same, and that various changes may be made in the shape, size and arrangement of parts thereof, without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, 1 claim:

1. In a two stroke engine including a housing having at least a pair of axially spaced cylinders extending therefrom in opposite directions and axially aligned with each other, means communicating with said cylinder to define a combustion chamber, means introducing fuel into said combustion chamber, a piston mounted in each of said cylinders for simultaneous reciprocating movement, said cylinders each communicating at its respective outer end with a closed extension chamber of enlarged diameter, and each of said pistons including a head of enlarged diameter complementary to and reciprocally movable within said extension, means in the closed ends of each of said extensions selectively admitting atmospheric air into said extension chamber of said cylinder upon movement of said piston toward said combustion chamber, said portion of said piston head of enlarged diameter including valve means for admitting said atmospheric air in said extension chamber from the portion of said chamber at one side of said head to the portion of said chamber at the opposite side of said head when said pistons are moved outwardly in said cylinders away from said combustion chamber communicating means, a crank shaft extending through the space between said cylinders and provided with a pair of axially spaced eccentrics for each piston, a piston pin extending diametrically through each of said pistons, connecting rods interconnecting each of said eccentrics with said piston pins, means defining passageways extending within the walls of said cylinders and said extensions parallel with the axis of the cylinders and extensions for selectively conducting air from said chambers to said combustion chamber upon movement of said piston heads toward.

the combustion chamber, and'exhaust means associated with each of said cylinders for discharging exhaust gases from said cylinders.

2. An engine as defined in claim 1 wherein said passageways are provided with first and second valve means communicating with said combustion chamber. said first valve means being normally opened and closed upon the predetermined advancement of said piston toward said combustion chamber, said second valve means being normally closed but operable to the open position upon movement of said piston toward said combustion chamber after said first valve means is closed.

3. An engine, as defined in claim 1, wherein said passageways are provided with first and second valve means communicating with said combustion chamber, said last-named valve means being normally closed, but operable to the open position upon movement of said pistons toward said combustion chamber after said first valve is closed.

4. An engine, as defined in claim 1, wherein said cylinders have passageways therein extending parallel with the axes of the cylinders, said passageways extending to said combustion chamber, means for admitting a fluid into said passageway, and means responsive to movement of said pistons for forcing said fluid from said passageways into said combustion chamber.

5. An engine, as defined in claim 4, wherein said lastnamed means comprises plungers mounted for slidable movement in said passageways.

Claims

1. In a two stroke engine including a housing having at least a pair of axially spaced cylinders extending therefrom in opposite directions and axially aligned with each other, means communicating with said cylinder to define a combustion chamber, means introducing fuel into said combustion chamber, a piston mounted in each of said cylinders for simultaneous reciprocating movement, said cylinders each communicating at its respective outer end with a closed extension chamber of enlarged diameter, and each of said pistons including a head of enlarged diameter complementary to and reciprocally movable within said extension, means in the closed ends of each of said extensions selectively admitting atmospheric air into said extension chamber of said cylinder upon movement of said piston toward said combustion chamber, said portion of said piston head of enlarged diameter including valve means for admitting said atmospheric air in said extension chamber from the portion of said chamber at one side of said head to the portion of said chamber at the opposite side of said head when said pistons are moved outwardly in said cylinders away from said combustion chamber communicating means, a crank shaft extending through the space between said cylinders and provided with a pair of axially spaced eccentrics for each piston, a piston pin extending diametrically through each of said pistons, connecting rods interconnecting each of said eccentrics with said piston pins, means defining passageways extending within the walls of said cylinders and said extensions parallel with the axis of the cylinders and extensions for selectively conducting air from said chambers to said combustion chamber upon movement of said piston heads toward the combustion chamber, and exhaust means associated with each of said cylinders for discharging exhaust gases from said cylinders.

2. An engine as defined in claim 1 wherein said passageways are provided with first and second valve means communicating with said combustion chamber, said first valve means being normally opened and closed upon the predetermined advancement of said piston toward said combustion chamber, said second valve means being normally closed but operable to the open position upon movement of said piston toward said combustion chamber after said first valve means is closed.

5. An enginE, as defined in claim 4, wherein said last-named means comprises plungers mounted for slidable movement in said passageways.