US2150162A - Internal combustion engine - Google Patents

Description

March I4, 1939. E. s. HALL- 2,150,162

INTERNAL COMBUSTION ENGINE Filed March 23, 1936 V 3 Sheets-Sheet l INVENTOR.

March 14, 1939. v E. s. HALL 2,150,162

INTERNAL COMBUSTION ENGINE Filed March 23, 1956 s Sheets-Sheet INVENTOR.

E. S. HALL INTERNAL COMBUSTION ENGINE I March 14, 1939.

Filed March 23, 1 936 s Sheets-Sheet 3 IN VEN TOR.

Patented Mar. 14, 1939 UNITED STATES PATENT OFFICE 6 Claims.

- This invention relates to internal combustion engines, andhas for its main object the provision of an opposed-piston engine of unusually compact form and simple construction. This object is attained by using the barrel engine cylinder arrangement, the cylinders being parallel to the shaft, with two coaxial reciprocating-rotary engine mechanisms whose piston members have pistons operable in the same set of cylinders.

Ordinarily in opposed-piston barrel engines, two engine mechanisms are mounted on the same rather long shaft; the opposed piston thrusts tend to bend the shaft, and may cause early fracture. An oject of this invention is to avoid this 16 difficulty by mounting the two reciprocatingrotary engine mechanisms independently, each with a short shaft on its own journal and thrust bearings in the engine casing members, so that the tensile and bending loads between the ends of the engine arising from the opposed piston thrusts, are carried by the flxed members off-the engine which are naturally well adaptedto carry such loads without appreciable deflection. Another object of this invention is to provide, in an opposed-piston barrel engine, cylinders having intake ports toward one end and exhaust ports toward the other end, constructed and arranged so that all of the ports can be accurately located, of ideal form, and readily machined, and so that the intake ports of the several cylinders can be fed from a common windchest to insure uniform distribution of the air, while the exhaust ports discharge into separate exhaust elbows to prevent the exhaust of one 35 cylinder from blowing into the ports of adjacent cylinders. A further object is to provide sure and adequate cooling to all port bridges. These objects are attained by providing individual cylinder units each having its own annular water jacket thru which the ports extend more or less radially, with axial water passages thru the port bridges. These cylinder units extend thru a common windchest casing member, and thru individual exhaust elbows, and are bolted between two engine casing members having chambers for the cooling fluid forming manifolds connecting the ends of the several cylinder Jackets. Axial flow of the cooling fluid thru the cylinder jackets and thru the port bridges can be maintained by pumping the fluid into the chamber of one of the engine casing members while permitting it to flow out of the other, suitable radiator means being included in the circuit as usual.

In an opposed-pistonengine, the pistons which uncover the exhaust ports run hotter than those which control the intake ports, and in theabsence of any special cooling means within the pistons, the size of the exhaust pistons is limited by their ability to stay cool enough, while the intake pistonscan be somewhat larger without running any hotter. It is advantageous, therefore, with the object of getting the most displacement into a given engine bulk, to make the exhaust pistons somewhat smaller in diameter than the intake pistons, and a secondary advantage is the ability to take more intercylinder.

' room between adjacent exhaust cylinders to accommodate the individual exhaust outlet members and provide for free flow of the exhaust from the inner sides of the cylinders.

Another object of the invention is to provide for reasonably tight connections between the several exhaust outlets and the exhaust manifold, in spite of heat stresses, by leaving each individual elbow some slight freedom to swivel about its cylinder with suitable ring packing, and by having all manifold gaskets in a common plane.

Other objects of this invention are to provide adequate and efficient reciprocating-rotary engine mechanisms for an opposed-piston barrel engine. In discussing barrel engine mechanisms, it is convenient to distinguish between a swashplate and a wabbler. Both are platelike structures inclined to the shaft and concentric with the shaft. In the following, it will be understood that a 'swashplate rotates with the shaft, being fixed thereon, while a wabbler does not rotate with the shaft, being mounted on bearings on the shaft, the axis of the bearings being inclined to the axis of the shaft. In some wabbler mechanisms, the wabbler is mounted on a Z-crankshaft; in others, the wabbler is mounted upon a swashplate.

In barrel engine mechanisms, particularly of the opposed-piston type, efficient and fully satisfactory means vfor taking the torque reaction from the operation of the reciprocating-rotary engine mechanisms have not been easy to provide. By the use of suitable wabbler mechanisms, the torque reaction can be made to appear as side thrust of the piston members, and an object of this invention'is to provide in an opposed-piston engine, cylindrical guide surfaces for the piston members, coaxial with the cylinders and extending longitudinally across the wabbler case,

so that the side thrust of the piston members can equivalent of the crosshead in crank engines, but is without the complication and added bulk usually associated with crosshead construction. A further object is to provide improved accessibility in an opposed-piston barrel engine, whereby the piston members and their operable connections with the wabbler may be readily assembled and removed. 7

These and other objects of the invention may be more completely understood from the following description in connection with the drawings in which:

Fig. 1 is a longitudinal sectional view of the forward portion of the engine, taken substantially on the line A-A of Fig. 3;

Fig. 2 is a longitudinal sectional view of the after portion of the engine, taken substantially on the line A-A of Fig. 3; and

Fig. 3 is a partial transverse sectional view of the engine, taken on the line 3-3 of Fig. 1.

Fig. 4 is a partial transverse sectional view, taken on the line 5- 3 of Fig. 2.

Fig. 5 is a partial transverse sectional view, taken on the line 5-5 of Fig. 2.

Referring to the drawings, hollow shaft it is mounted in journal bearings M in casing 2t and casing cover 2!, and is located axially by pivoted slipper thrust bearing l2. Instead of the plain and slipper bearingsshown, anti-friction bearings could be used if desired. Splined on shaft i0 is swashplate member it having plane working faces and a spherical central boss. The spherical boss provides a substantial means for mounting the swashplate on shaft ill, and makes possible easy machining of swashplate member l3 since all its exterior surfaces are surfaces of revolution relative to the swashplate axis, while the splined hole thru the hub is easily machinable relative to the axis of the hole, the two axes intersecting at the center of the spherical boss.

The spherical boss also forms a self-aligning pilot member for wabbler 30, which is composed of two similar portions bolted together about swashplate l3. Wabbler 30 has bearing elements coactingwith the plane working faces and spherical pilot boss surfaces of swashplate 63. These bearing elements maybe plain bearing surfaces conforming to the surfaces of swashplate E3, or slipper elements such as slippers 3i pivoted in wabbler 3i] and having working faces to coact with the surfaces of swashplate l3.- Wabbler 3G is substantially U-shaped in section, and is fed with oil thru holes M in swashplate It, the centrifugal action of the swashplate maintaining wabbler 30 full of oil during operation. Oil holes H3 lead oil from Within shaft ill to the points on swashplate l3 that are normally either not loaded or carrying less load than the other parts of swashplate l3. Slippers 3i areshown on one side only of swashplate member l3, with plain bearings on the other side. Slippers could be provided on both sides, and on the spherical pilot surface also, or they could be omitted entirely and plain bearings used if desired.

Wabbler 30 has arms 33 attached thereto by screws 32. Each arm 33 is provided with a cylindrical bore 36 whose axis is substantially in the mid-plane of and tangent to a circle concentric with wabbler 3t. Pin 35, a free fit in cylindrical bore til of arm 33, is carried by crosshead 35 which is a free fit in a cylindrical bore ii in piston member at. Piston member it carries piston rings 53 slidable in cylinder 52 of cylinder member 56. The portion of piston member so in which is bore it, is larger in diameter than the piston proper, and has bearing shoes 42 freely fitting cylindrical guide surfaces 22 formed in casing 20 coaxial with cylinder 52.

The after reciprocating-rotary engine mechanism is similar to the forward mechanism Just described. Hollow shaft 60 is mounted in journal bearings Si in casing 10 and casing cover H, and is located axially by pivoted slipper thrust bearing 62. The swashplate-wabbler construction is an inversion of that shown in Fig. 1. swashplate members 63 are splined on shaft 50 and are spaced apart by spherical pilot member 65. Wabbler is piloted on member 65 and lies between swashplate members 63. Plain bearing elements of wabbler 80 conform to the bearing surfaces of swashplate members t3 and pilot member 55, or slipper elements such as slippers 8! may be used if desired. Plates 88 with the rim section of wabbler 80 to which they are attached, form a U-shapedsection to contain an oil bath for the bearing elements to work in, the centrifugal action of swashplate members 88 assisting in maintaining the oil bath within the U-sectioned ring of the wabbler.

Wabbler 80 has arms 83 attached thereto by screws 82. Each arm 83 is provided with a cylindrical bore whose axis is substantially in the mid-plane of and tangent to a circle concentric With'wabbler 80. Pin 85, a free fit in bore 8 5 of arm 83, is carried by crosshead 86 which is a free fit in cylindrical bore 9! in piston member 90, which carries piston rings 93 slidable in cylinder 53 of cylinder member 50. The portion of piston member in which is bore M, is larger in diameter than the piston proper, and has bearing shoes 52 freely fitting cylindrical guide surfaces 12 formed in casing l0 coaxial with cylinder 53.

Cylinder members 50 are individual units, each having an annular water jacket 5| and a belt of intake ports 5% and a belt of exhaust ports 55, the port bridges having axial water passages 56. Surrounding each cylinder member 50 is an individual exhaust elbow 25, having a flanged outlet bolted to exhaust manifold 26. All cylinder members 50 extend thru common windchest 14 formed in casing member 15. Cylinder members 50pilotintoholes in the inner ends of casing members ZbandliLand arebolted to casing members 20 and 10 by bolts Zl, between which water ports 51 communicate with water chambers 23 and It in casing members 20 and 10 respectively, these chambers 28 and 78 forming water manifolds connecting the water jackets 5| of the several cylinders 50. The same gaskets which seal the joint between the ends of Water jackets 5i and casing members 20 and 10, also assist in sealing the joints between exhaust elbows 25 and casing 20, and casing member 15 and casing 10. Annular soft packing 58 is used to seal the inner ends of exhaust elbows 25 and casing member 15 relative to individual cylinder members 50. Casing member 75 extends forward around shaft in to form an oil tight sealed closure with casing member 20. During operation, cylinder members 50, being at higher temperature, expand more than the forward extension of casing 15. To take care of this condition, expansion joint H5 is provided between casing member 20 and casing member 15.

The common windchest 15 which supplies air to all intake ports 54, is connected by conduits 'l'i' with a'plurality of centrifugal blower units 75 mounted on the accessory assembly 91 at the rear of the engine. Conduits ll could be formed integrally in casing m if desired.

Shaft 60 is keyed to bevel gear I! meshing with one or more pinions I 8 mounted in bearings in member i5 and adapted to drive various accessories thru radiating drive shafts l9. Shaft 58 is inserted thru shaft 60 and then thru shaft l0, and is driven by shafts l0 and 60 in any suitable manner compelling all three shafts to rotate together while permitting some misalignment of shafts I0 and 60 without deflection of shaft 68.

Means should also be provided for convenient adjustment of the relative rotational position of shafts l0 and 60 in order to adjust the phase relationship of piston members 40 and 90. The means suggested comprises relatively short involute splines, fifteen splines H5 connecting shafts l0 and 68 and sixteen splines 6 connecting shafts 60 and 68, the Vernier effect making possible adjustment of the rotational position of the shaft in relative to shaft 60 by increments of 1.5 degrees.

Fuel injection nozzles 59 are served by individual fuel pumps 39 which are operated by radiating push rods 38 and cam followers 31 which are driven by cam l8 fixed on shaft l0.

Casing member 20 has handholes 23 closed by covers 29, and 'cover 2i has handholes 24 closed by covers 49, to provide accessibility to pistons 40 and wabbler arms 33 and associated parts. Casing member 10 has handholes l3 closed by covers 81, and cover II has handholes 16 all of which are closed by the accessory assembly 91, to provide accessibility to pistons 90 and wabbler arms 83 and associated parts.

During assembly, the fuel injection system and accessory drive gears may be assembled in casing member 15, cylinders inserted thru member 15, and casing member ID bolted thereto by bolts 21. Then exhaust elbows 25 and casing member 20 can be assembled. The principal fixed parts of the engine are now formed as a rigid assembly having numerous advantageous features such as a common windchest to serve all intake ports, individual exhaust elbows which can be adjusted to line up properly and bolt tightly to manifold 26, and the possibility of axial flow of the cooling medium thru all cylinder water jackets and port bridges. This construction also makes possible the complete-machining of all cylinder ports, and is also more convenient in other ways than a mono-bloc construction in production. After shafts l0 and 50, with their thrust bearings, swashplate and wabbler. members, and easing covers 2| and H have been assembled, piston members 40 and 90 may be inserted thru handholes24 and I6 respectively, and wabbler arms 33 and 83, with their associated parts, may be inserted thru handholes 23 and 13 respectively, and fastened to wabblers 30 and 80 by screws 32 and 82 respectively. Obviously, the pistons and wabbler arm assemblies are easily accessible thru the handholes, for inspection and repair or replacement, without major disassembly of the engine.

0peratio'n. The engine as shown and described may operate with compression ignition in the manner well-known in opposed-piston engines, tho spark ignition could be provided if desired. Air from blower units I9 is conducted thru conduits 11 to windchest 14, from which it is admitted to each of cylinders thru ports 54 in a swirling blast whenever ports 54 are uncoveredby pistons 90, while the exhaust passes out thru ports 55, uncovered by the piston 40, thru elbows 25 to manifold 28. Pistons 40 and 90, approaching each other, compress the char e of air, and at the right moment. a shot of fuel after mid-stroke on compression when piston inertia may exceed the compression pressure), but the outward thrusts of the opposing pistons are not balanced relative to the center of the engine, being considerably greater on the side where the pistons are at "top center position.

. If the two engine mechanisms are fixed on the same shaft, as usually arranged, the unbalanced condition tends to bend the shaft; either the shaft must be made very rigid and strong to carry the bending load safely, or the shaft bearings must be able to support the shaft adequately against bending. This difllculty is avoided in the present invention by providing separate shafts I l! and 60 for the two engine mechanisms, mounting each shaft on adequate journal and thrust bearings, so that the bending load is transferred to the casing members which. are naturally able to carry them. Slipper thrust bearings such as i2 and 62 may be used, and may be located either outwardly or inwardly from the respective engine mechanism.

Another important-objective reached by this construction is the ability to adjust conveniently the phase relationship between the exhaust pistons and the intake pistons. Piston 40 should open the exhaust ports to permit the cylinder pressure to drop to atmospheric before piston 90 opens intake ports 54, and it is also desirable that exhaust ports 55 close before intake ports 54 close to permit supercharging the cylinder to blower pressure. It is customary, therefore, in opposedpiston engines, town the exhaust pistons somewhat in advance of the intake pistons, the optimum phase relationship being determined by trial.

The various engine accessories such as the oil and water pumps, and scavenging blowers 19, are not included in detail in the present invention. Some may be driven by radial drive shafts l9; others may be grouped in an easily removable accessory assembly 91 at the rear of the engine. If shaft must drive thev accessories and at the same time do its part in turning shaft 68, more power must be developed by the after reciprocating-rotary engine mechanism than by the forward one. This may be accomplished by making pistons 90 of greater diameter than pistons 40,

' cylinders 53 being of larger bore than cylinders 52. Other advantages of making the exhaust pistons smaller than the intake pistons have already been discussed.

Plain bearings between the working faces of swashplate members I3 and 63, and wabblers 30 and 80 respectively, can carry the thrust loads imposed upon them only by virtue of the progressive rotation of the maximum load area around the wabbler during operation, which action, combinedwith the freedom of the wabbler to rock on its spherical pilot, will tend to maintain wedgefilm lubrication between the coacting plane surfaces. In view of the continuously unidirectional thrust load on the wabbler bearings in an opposed-piston barrel engine, pivoted slipper bearing's are preferred, since they are able, as is'wellknown, to maintain the desired wedge-film lubrication of their working surfaces by tilting on their pivots. The underslung type of slipper illustrated is also free to rotate in its socket at will, promoting good lubrication of the socket and free tilting action. Flooded lubrication, with the bearing elements operating in an oil bath, as provided in this invention, is practically essential to the success of either plain or slipper bearin s in a wabbler mechanism.-

With the particular type of piston-wabbler connections shown, the torque reaction appears as side thrust on the piston members. In the present invention, this side thrust is carried by shoes '42 or 92 directly to cylindrical guide surfaces 22 or 12 respectively, and piston members 40 and 90 are not subjected to any beam loading, the pistons proper serving only their primary function as ring carriers. Cylindrical guide surfaces such as surfaces 22 and I2 are easily and accurately machined in the casing members, and can be arranged coaxial'with the cylinders without any difficulty. The spaces between the guide surfaces may be occupied by cooling fluid as indicated in the drawings, or could be used as conduits to transfer air from blower units 19 to windchest 14 if desired.

Having thus described the invention, it is clear that all the objects as stated herein have been attained. While I have shown particular structures, it is understood that changes in the arrangement and in the construction of the various parts may be made without departing from the spirit or scope of the invention as expressed in the following claims. a

I claim:

1. In an opposed-piston barrel engine, aconstruction for the fixed parts of said engine comprising engine casing members, chambers in said casing members for the cooling fluid of said engine, individual cylinder members arranged parallel to each other and to the main axis of said engine and extending from one of said casing members to the other, annular water jackets on said individual cylinder members, said chambers in communication with and forming water manifolds for said annular water jackets, intake 'ports toward one end and exhaust ports toward the other end of each of said cylinder members said ports extending thru said annular water jackets with intervening axial water passages, a pressure chamber or windchest formed in one of said casing members and enclosing the intake port portions of said individual cylinder members and in common communication with said intake ports, and individual exhaust collectors enclosing and associated with the exhaust port portion of each of said individual cylinder members.

2. In an opposed-piston barrel engine, a shaft, individual cylinder members having cylinders parallel to said shaft, intake ports toward one end and exhaust ports toward the other end of each of said cylindersftwo sets of pistons operably opposed insaid cylinders the pistons of one set controlling the intake ports and the pistons of the other of said sets controlling the exhaust ports, operable connections between said pistons and said shaft, a pressure chamber or windchest enclosing the intake port portions of said individual cylinder members and in common communication with said intake ports, individual exhaust collectors each enclosing and associated with the exhaust port portion of one of said individual cylinder members to prevent the exhaust from one cylinder from blowing into the ports of adjacent cylinders, the exhaust port portions of said cylinders and the pistons controlling exhaust being of smaller diameter than the intake portions of said cylinders and their pistons in order to provide enough room between cylinders for said individual exhaust collectors while permitting maximum total displacement in the engine.

3. A construction for the fixed parts of an opposed-piston barrel engine comprising two similar engine casing members spaced apart, chambers in said casing members for the cooling fluid ofsaid engine, individual cylinder members arranged parallel to each other and to the main axis of said engine and extending from one of said casing members to the other, annular jackets for cooling fluid on said individual cylinder members and connecting the said chamber of one of said casing members with the chamber of the other, intake ports toward one end and exhaust ports toward the other end of each of said cylinder members said ports extending thru said annular jackets with intervening port bridges having axial passages for the cooling fluid, a third casing member capable of forming the mainsupporting frame of the engine and extending from one of said similar casing members to the other and surrounding the intake portions of said cylinder members enclosing them in a common pressure chamber orwindchest in common communication with said intake ports, and individual exhaust collectors each surrounding the exhaust port zone of one of said cylinder members.

4. A construction for the fixed parts of an opposed-piston barrel engine comprising two similar engine casing members spaced apart, chambers in said casing members for the cooling fluid of said engine, individual cylinder members arranged parallel to each other and to the main axis of said engine and extending from one of said casing members to the other, annular jackets for cooling fluid on said individual cylinder members and connecting the said chamber of one of said casing members with the chamber of the other, a third casing member extending from one of said similar casing members to the other and surrounding portions of said cylinder members and forming an oil-tight closure from one of said similar casing members to the other, and an expansion joint between two of said three casing members.

5. A construction for the fixed parts of a twostroke barrel engine comprising engine casing members, individual cylinder members attached thereto, exhaust ports in said cylinder members, and individual exhaust elbows each surrounding the exhaust port portion of one of said cylinder members in a manner permitting said elbow to swivel slightly about said cylinder member.

6. A construction for the fixed parts of a twostroke barrel engine comprising engine casing members, individual cylinder members extending from one of said casing members to another, exhaust ports in said cylinder members, individual exhaust elbows each surrounding the exhaust port portion of one of said cylinder members in a manner permitting said elbow to swivel slightly about said cylinder member, and a plane flanged outlet on each of said elbows, the flanged outlets of the several elbows being substantially in a common plane for convenient attachment to a common manifold.

EDWIN'YS.

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