CA1226147A - Engine - Google Patents
EngineInfo
- Publication number
- CA1226147A CA1226147A CA000461491A CA461491A CA1226147A CA 1226147 A CA1226147 A CA 1226147A CA 000461491 A CA000461491 A CA 000461491A CA 461491 A CA461491 A CA 461491A CA 1226147 A CA1226147 A CA 1226147A
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- CA
- Canada
- Prior art keywords
- piston
- piston rod
- crank
- center
- aye
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Abstract
ABSTRACT OF THE DISCLOSURE
To reduce space requirements, vibrations and cer-tain stresses in an engine, a different one of two pistons is mounted on each end of a single piston rod to which the crankshaft is attached by a cylindrical shaped connector that orbits around the crankpin while rotating inside the piston rod. The crank interfaces directly with the piston rod through gear portions or a cam-cam follower through the center of each stroke. To reduce vibrations and certain stresses in an engine, a dif-ferent one of two pistons is mounted on each end of a single piston rod to which the crankshaft is attached by two arms extending orthogonally from its central por-tion, each arm being mounted to a different one of two different connecting rods. To balance inertia forces, two oppositely rotating crankshafts are counter-weighted to balance the inertia forces of the assembly in its axis of oscillation and to balance each other outside that axis of motion, or two piston assemblies oscillate opposingly in the same axis eliminating the need for the crankshafts to balance their inertia forces.
To reduce space requirements, vibrations and cer-tain stresses in an engine, a different one of two pistons is mounted on each end of a single piston rod to which the crankshaft is attached by a cylindrical shaped connector that orbits around the crankpin while rotating inside the piston rod. The crank interfaces directly with the piston rod through gear portions or a cam-cam follower through the center of each stroke. To reduce vibrations and certain stresses in an engine, a dif-ferent one of two pistons is mounted on each end of a single piston rod to which the crankshaft is attached by two arms extending orthogonally from its central por-tion, each arm being mounted to a different one of two different connecting rods. To balance inertia forces, two oppositely rotating crankshafts are counter-weighted to balance the inertia forces of the assembly in its axis of oscillation and to balance each other outside that axis of motion, or two piston assemblies oscillate opposingly in the same axis eliminating the need for the crankshafts to balance their inertia forces.
Description
ENGINE
This invention relates to reciprocating piston - engines.
In one class of combustion engines, the engine includes reciprocating pistons which drive an eccentric gaily mounted cam shaft through piston and connecting rods. Such engines are subject to vibrations resulting from periodic unbalanced vertical inertia forces of pistons and connecting rods and lateral inertia forces created by crankshaft counterweights as they rotate. To reduce the effect of this vibration, multiple cylinders are frequently included.
In prior art types of this class of engine, Libra-lions are reduced by increasing the number of cylinders 'i and the length of the connecting rods. I
The prior art engines have several disadvantageSsuch as (1) a large number of cylinders increases costs and complexity, especially in diesel engines; (21 if long connecting rods are used, engine size is increased, I if the rod length to crank radius ratio it `.
decreased, the ratio of inertia forces for the top of the stroke compared to the bottom of the stroke is increased, and the ratio of time that the piston spends in the upper half of the stroke as opposed Jo the lower half is decreased which respectively increases Libra-I;' ~2~4~t' tonal problems, decreases fuel burn time per revolution and limits maximum diesel RPM; and (4) the crankshaft deaccelerates the pistons as they approach the end of each stroke and then reaccelerates them, resulting in high stress on cranks, bearings and other components plus energy robbing friction.
To provide a novel engine which is improved in some respects, the apparatus comprises a piston rod adapted to be reciprocated within an engine with a predetermined stroke length, a crank and a crank pin having a center with the center of the crank pin having a predetermined radius of rotation about an axis of crank rotation; an attaching means connects at least one piston to said piston rod, whereby said rod is driven by said piston in the direction of motion of said piston. A connector means is adapted to be attached at a predetermined location on said connector means to the crank pin, said connector means being rotatable mounted to said piston rod about predetermined center of connector rotation with the distance from the center of rotation of said connector means with respect to said piston rod and the predetermined location of connection to said crank pin being equal to said predetermined radius of crank rota-lion.
Advantageously, said piston stroke length is equal to substantially four times the crank radius, the connector means rotates with the same angular velocity but in the opposite direction as the crank, and there is an interface means between said crank and said piston rod that engage at least a length of surfaces sub Stan-tidally at mid stroke to force continuity of piston rod movement with a component of velocity of the piston rod being twice the velocity of the crank pin center in the direction of oscillation of the piston rod through a predetermined portion of mid stroke. Moreover, the interface means may be a cam slider.
There may be at least first and second combustion chambers, at~least.fi~rst and second-reciprocating pistons adapted to reciprocate in corresponding combustion chambers, at least two crankshafts, connect tying means attached to said reciprocating pistons for driving said two crankshafts as said first and second pistons reciprocate, means connected to said crankshafts for obtaining mechanical power therefrom, said means connected to said first and second reciprocating pistons comprising a piston rod having first and second ends, said piston rod having mounted to it said first piston on said first of its ends and said second piston on said second of its ends for reciprocating motion therewith, said crankshafts each having a different main bearing about which they rotate, each of said crankshafts having different web portions and different erankpins, whereby they are eccentrically mounted to provide a flywheel effect and rotate in opposite directions to each other and lubrication means for applying a lubricant to said piston rod at a location removed from said combustion chambers.
The piston rod includes substantially flat parallel sides, said means for connecting said connector means to Swede piston rod, including internal walls defining a cylindrical aperture extending between said parallel -flat sides, two edges of said parallel flat sides are rigidly fastened to one piston, the opposite two edges of said flat parallel sides being rigidly fastened to a second piston, whereby said first and second piston drives said piston rod in opposite directions, said means fur connecting at least one erankpin includes internal walls defining first and second cylindrical apertures, each of said cylindrical apertures being audited to mount a different connector means, said first and second apertures being aligned with each other in a direction at an angle to the direction of motion of said piston rod, a second piston rod, second means for moving said second piston rod in a reciprocating motion, said second piston rod being aligned with said first piston ~6~L~7 rod, means for connecting a piston to edges of said second piston rod, said means of connecting a piston to said second piston rod being between said second piston rod and said first-mentioned piston rod; a crankcase;
said first and second piston rows each being connected at one end to said piston at its other end to a different crank pin on a different one of said crank shafts, said piston rods and crankshafts being mounted within said crankcase, first and second cylinders mounted outside said crankcase aligned with said piston rods, said cylinders each being on a different end of said piston rod, and said first piston fitting within said first cylinder and said second piston fitting with-in said second cylinder.
The first and second crankshafts are mounted parallel to each other with tube same plane passing through their axes and parallel to said piston rod in a plane perpendicular to the plane of said piston rod. A
first gear is mounted to said first crankshaft for rotation therewith, a second gear mounted to said second crankshaft for rotation therewith, and a shaft mounted for rotation to one of said first and second gears for providing power from said engine. The engine is a two-cylinder diesel engine and includes diesel fuel injection means for injecting diesel fuel into one of ~Z2614~
said cylinders at the end of each compression stroke, vent means for venting exhaust fumes during the power stroke of said pistons, a plenum chamber, vent means connected between each of said cylinders and said plenum chamber for causing air to be moved under pressure into said plenum chamber by said piston during said power stroke, and second vent means communicating between said plenum chamber and said cylinder causing air under pressure to escape from said plenum chamber into said cylinder when said piston is substantially at the end of its power stroke.
The interface means may include rack and pinion gearing in which the pinion drives the rack to a velocity twice that of the crank pin center in the direction of piston rod oscillation; may include gearing in which the crank gear drives the piston rod gear to a velocity twice that of the crank pin center in the direction of piston rod oscillation; and may include a means for imparting motion through a predetermined distance of mid stroke from the crank to the piston assembly wherein the piston assembly achieves its maximum velocity at mid stroke and the maximum velocity is substantially twice the orbital velocity of the center ox the crank pin about the axis of crank rotation.
the above noted and other features of the .
~2~7 invention will be understood more completely from the following detailed description when considered with reference to the accompanying drawings in which:
FIG. 1 is a simplified sectional view of an embodiment of the invention;
FIGS 2-5 are developed views showing the operation of the embodiment of FIG. 1 with a slightly different apparatus;
Fig 6 is a simplified plan view, in section, showing a portion of the embodiment of FIG. l;
FIG. 7 is an exploded perspective view of a portion of another embodiment of the invention;
FIG. 8 is a simplified illustrative view of the embodiment of FIG. 7;
FIG. 9 is a sectioned, simplified elevation Al view of an embodiment of the invention;
FIGS 10-13 are developed views illustrating the operation of the embodiment of FIG. 9;
FIG 14 is an elevation Al view of still another embodiment of the invention;
FIG. 15 is a longitudinally-sectioned, elevation Al view of still another embodiment of the invention;
FIG. 16 is a longitudinally-sectional top view of the embodiment of FIG. 15; and FIX. 17 is a simplified perspective view of a portion of the embodiment of FIG. 7;
FIG. 18 is a longitudinally-sectioned, elevation Al view of still another embodiment of the invention; and FIG. 19 is a longitudinally-sectioned top view of the embodiment of FIG. 18.
In FIG. 1, there is shown a two-cylinder, two-cycle, balanced diesel engine 10 having first and second cylinders AYE and 12B and a crankcase 16. The first and second cylinders AYE and 12B are aligned with each other on common axis which passes through the center of the crankcase 16 for cooperation with a single piston rod 20 therein. Generally, the first and second cylinders AYE and 12B and the axis are vertically oriented but horizontal orientation is possible.
The crankcase 16 includes a housing 18 forming a compartment which supports the first and second cylinders AYE and 12B on opposite sides and has located along a central axis between the first and second cylinders AYE and 12B the single piston rod 20 aligned with the first and second cylinders AYE and 12B so that as the single piston rod 20 moves further into the first cylinder AYE, it moves further out of the second cylinder 12B and vice versa. Extending outwardly from opposite sides of the single piston rod 20 within the housing 18 are two wings, AYE and 22B, each having on its end a corresponding one of the bores AYE and 24B
containing a corresponding one of the bearing shells AYE
and 26B. A first connecting rod 28~ has one end rotatable mounted in the bore AYE for rotation within bearing shell AYE and a second connecting rod 28B has one end mounted within the bore 24B for rotation with the bearing shell 26B.
Eccentrically mounted to the first connecting rod AYE is a first crank AYE and eccentrically mounted to the second connecting rod 28B is a second crank 30B. On the opposite ends of the single piston rod 20 and within the respective cylinders AYE and 12B are conventional pistons 32~ and 32B respectively. The conventional pistons AYE and 32B are mounted so that as one moves toward the crankcase 16, the other moves away from the crankcase 16 so that one of the conventional pistons is compressing air in the case of a diesel engine while the other is being powered by the expanding gas formed after ignition.
In the preferred embodiment, the diesel engine 10 is a two-cylinder diesel engine and consequently the cylinders AYE and 12B include cylinder walls AYE and 34B respectively which receive conventional diesel fuel injectors AYE and 36B respectively. The timing of the fuel injection, air compression and venting it Canaan-~2~6~4~
tonal except that cylinders include corresponding towardly plenum chambers AYE and 38B formed by towardly walls BOA and 40B positioned to ye vented into and from corresponding ones of the cylinders AYE and 12B.
To cause the compression of air in the towardly plenum chambers AYE and 38B and use of the compressed air to aid in exhausting the cylinders AYE and 12B, vent ports are positioned in the cylinder walls AYE and 34B
to communicate between the towardly plenum chambers AYE
and 38B and the corresponding inner chambers of the cylinders AYE and 12B such as shown at AYE and 42B
and AYE and 44B. Vents are also positioned in the cylinder walls AYE and 34B at a position adjacent to the top of the towardly plenum chambers AYE and 38B to communicate between the inner part of the corresponding cylinders AYE and 12B and the portions of the toroldal plenum chambers AYE and 38B most remote from the crankcase 16 such as those shown at AYE and 46B and at AYE and 48B.
The conventional pistons AYE and 32B have a height in the direction of the longitudinal axis sufficient so that when they are in their uppermost position adjacent to the top of the cylinders AYE and 12B, all of the vents ox the cylinder walls AYE and 34B and the towardly plenum chambers AYE and 38B are open and when they are in their lowest position, closest to the crankcase 16, the vents adjacent to the crankcase 16 such as AYE, 42B, AYE and 44B are closed by its corresponding piston but the ones most remote from the crankcase 16 such as at AYE, AYE, 46B and 48B are open. With this structure, as the conventional pistons AYE and 32B move toward the crankcase 16, air is forced at first through both vents and then through the bottom vent in the towardly plenum chambers AYE and 38B and when they reach the position closest to the crankcase 16, the compressed air in the towardly plenum chambers AYE and 38B is released into the cylinders AYE and 12B to aid in exhausting it through the uppermost vents.
Exhaust vents are provided at a location where the rim of the conventional pistons AYE and 32B block them when the pistons AYE and 32B are in a position most remote from the crankcase 16 and permit them to be opened when they are in a position adjacent to the crankcase 16 such as at AYE and AYE for cylinder AYE and 50B and 52B for cylinder 12B. appropriate tubing is provided such as that shown schematically at AYE and AYE
and at 54B and SUB to remove the exhaust fumes when air is being forced into the cylinders AYE and 12B from the towardly plenum chambers AYE and 38B. The valving it conventional and will not be described in this ~226~L~7 application.
The crankshafts AYE and 30~ are each of conventional design and include a web portion AYE and 58B respectively, and a crank pin or crank portion AYE
and 60B respectively, each rotating about a corresponding one of the main bearings AYE and 62B. Of necessity, the web portions AYE and 58B, crank pins or crank portions AYE and 60B are positioned so that their centers of mass are offset from the axis of rotation of the crankshafts AYE and 30B and cause some vibration forces when orbiting about the axis of rotation. The crankshafts AYE and 30B are arranged about the single piston rod 20 on opposite sides thereof within the crankcase 16 and on the same side of the wings AYE and 22B with their web portions AYE and 58B being oriented in the same position with respect to the cylinders AYE
and 12B so as to balance their inertia forces in a direction orthogonal to the single piston rod 20 during rotation.
The crankshafts AYE and 30B are sufficiently heavy to serve as fly wheels, and when they rotate, their web portions AYE and 588, rotate toward the single piston rod 20 and away from the single piston rod 20 at the same time. Thus, the lateral inertia forces cancel between the two crankshafts. Moreover, the conventional ~L2;26~L~7 pistons AYE and 32B and cylinders AYE and 12B are arranged so that one piston is going through the power stroke moving downwardly in an opposite direction with respect to the crankcase 16 as the web portion so as to provide further balancing.
In FIGS. 2-5, there is shown a cycle of operation of the diesel engine 10 illustrating the manner in which the forces are balanced by the crankshafts AYE and 30B
during a cycle The diesel engine 10 shown in FIGS. 2-5 has a slightly different placement of the crankshafts AYE and 30B with respect to the side wings AYE and 22B
and the longer and shorter portions of the piston rod 20 but the principle is the same.
In FIG. 2, there is shown the conventional piston AYE at the end of its compression stroke and at the beginning of its power stroke after injection of the diesel fuel and the conventional piston 32B at the beginning of its intake stroke with the fumes being evacuated by compressed air from the towardly plenum chamber AYE (FIG. 1). In this position, the single piston rod 20 is closest to the cylinder AYE (Fig 1) within the crankcase 16 and the connecting rods AYE and 28B are substantially straight with the web portions AYE
and 58B being furthest from the wings AYE and 22B.
In FIG 3, the diesel engine 10 is shown with the Lo 7 conventional piston AYE about one-half through the power stroke in which it is compressing air in the towardly - plenum chamber AYE (FIG. 1) and the conventional piston 32B is compressing air within the cylinder 12B FIG. 1).
In this position, the wings AYE and 22B of the single piston rod 20 have moved in the direction of the Solon-don 12B (FIX. 1) rotating the web portions AYE and 58B
counterclockwise and clockwise respectively so the inert lie forces of each are toward the single piston rod 20 and cancel each other out within the crankcase 16. This direction of rotation is achieved because of the post-lion of bearings of crank pins AYE and 60B with respect to the main bearings AYE and 62B, the bearing of crank pins AYE and 60B being positioned further from the single piston God 20 than the main bearings AYE and 62B
at the beginning of the power stroke of conventional piston AYE with the single piston rod 20 closest to the cylinder AYE FIG. 1).
In FIG. 4, there is shown the diesel engine lo in a position in which the conventional piston AYE is exhausting fumes and in taking air and the conventional piston 32B is at the end of its compression stroke and the beginning of its power stroke after the injection of diesel fuel. In this position, the single piston rod 20 is closest to the cylinder 12B (FIG. 1) within the . .
26~4~7 crankcase 16 and the web portions AYE and 58B have rotated counterclockwise and clockwise respectively in the direction of the cylinder AYE, with their inertia forces in the direction towards cylinder AYE and opposing the inertia forces of the moving central embodiment (pistons and connecting mechanisms) which has inertia forces in direction towards cylinder 12Bt In FIG. 5, there is shown diesel engine 10 with the conventional piston AYE in the process of compressing air and the conventional piston 32B about one half through its power stroke in which position it is compressing air to the towardly plenum chamber 38B
(FIG, 1). In this position, the web portions and 58B are rotating counterclockwise and clockwise respectively with their inertia forces being outward from the single piston rod 20, thus balancing each other.
From FIGS, 2-5 it can be understood thaw the horizontal forcff~s toward and away from the single piston rod 20 caused by the inertia forces of the crankshafts AYE and 30B with web portions AYE and 58B oppose and thus balance each other while the vertical forces in the direction of the conventional pistons AYE and 32B are such that the inertia forces of crankshafts AYE and 30B
with web portions AYE and 58B oppose the inertia forces . .
I L4~7 ox the moving piston and connecting mechanisms (20, AYE, 22B, AYE, 24B, AYE, 26B, AYE, 28B, AYE, 32B, AYE and JOB). Since these forces oppose there is a minimum of vibration and lost power from vibration in the engine.
In FIG. 6, there is shown a top sectional view of the crankshafts AYE and 30B each mounted to rotate a different one of the gears AYE and 64B. The gears AYE
and 64B are engaged and the gear AYE drives an output shaft 68. In this manner, the crankshafts AYE and 30B
each drive a different one of the gears AYE and 64B in synchronism and output shaft 68 as the crankshafts AYE
and 30B are driven by the connecting rods AYE and 28B
(FIG. 1) engaging the crank pin AYE and 60B to turn the crankshafts AYE and 30B about the main bearings AYE and 62B.
In FIG. 7, there is shown a simplified, fragmentary perspective view of another embodiment of the invention having a unitary piston-piston row assembly 70 and a connector-crank assembly 72. The piston-piston rod assembly 70 reciprocates as part ova reciprocating engine and causes the connector-crank assembly 72 to rotate.
The piston-piston rod assembly 70 includes first and second pistons 32C and 32D and a piston rod AYE. The piston rod AYE is generally shaped as a right regular ~L22~7 parallelopiped having first and second parallel flat sides of equal dimensions, one of which is shown at 74, and curved parallel sides connecting the flat sides and having outer surfaces as cylinders, one of which is shown at 76.
On each side of the piston rod AYE is a corresponding one of the two pistons 32C and 32D
integrally formed therewith and having a generally cylindrical shape, with a major diameter equal to or approaching that of the curved parallel sides 76 and a cylindrical curvature the same as or approaching the curvature of the sides 76. The two pistons are separated by the length of the flat side 74. Centrally located in the piston rod AYE and passing between the flat sides is a cylindrical hole 78 adapted to receive the connector-crank assembly 72.
The piston-piston rod assembly 70 may be of unit construction as described or assembled by connecting pistons to the piston rod with fasteners. Curved surface 76 is in contact with the cylinder walls and absorbs the piston side thrust resulting from the forces of the piston through a connector on to the crank. The piston fit against the cylinder walls is looser than the fit of curved surface 76 receives Jo allow for its thermal expansion. The diameter of the crown of the piston is 26~
shorter than the diameter of the skirt portion by less than ten one-thousandths of an inch. In the preferred embodiment the curved surface 76 receives forced oil lubrication and is the primary surface resisting piston assembly side thrust. The surface 76 is also removed from the normal heat build up found in the combustion chamber.
The connector-crank assembly 72 includes a connector 28C, a crank pin 60C and crank journals AYE
and 59B. The connector 28C is cylindrical and sized to conform to hole 78 which receives it The crank your-nets AYE and 59B include pinion gears portions BOA and 80B on sides adjacent to piston-piston rod assembly 70 which interfaces with complimentary teeth on similar rack gear portions AYE and 82B respectively. Holes 84C
in connector 28C and holes BRA and 84B in crank journals AYE and 59B are sized to receive the cylindrical crank pin 60C. Crank pin 6GC may be rigidly attached or an integral part of journals guy and 59B and rotate freely in connector 28C or may be rigidly attached or an integral part of connector 28C and rotate in crank journals AYE and 59B. The center (axis of crank pin 60C
orbits about the center (axis) of crank journals AYE and 59B with the radius of orbit hereafter referred to as the radius of crank rotation.
When assembled, the connector 28C is within a hole 78 and is carried as a whole in the reciprocating motion of the piston-piston rod assembly 70 while it rotates therein. The crank pin 60C is within the hole 84C of the connector 28C within which it rotates while it orbits about the center of the connector 28C as the connector 28C and the piston-piston rod assembly 70 reciprocate.
This orbit has a radius equal to the radius of rotation of the crank 30C and causes rotation of the crank to impart rotary motion in response to the piston stroke, which is four times the radius of rotation of the crank or four times the radius of the rotation of the crank-pin about the center of the connector.
In FIG. 8, there is shown an illustrative drawing of the piston-piston rod assembly 70 at the bottom of its stroke and connector-crank assembly 72 having centerlines 86 and 88 for the piston-piston rod assembly 70 illustrating its direction ox motion an hidden lines 90 illustrating the motion of the crank pin 60C
with respect to center lines 87 and 8g of the crank 30C~
As shown in this figure, the piston-piston rod assembly 70 reciprocates in a linear direction along the lines 86 and 88. The center point 92 of the connector 28C reciprocates in the same direction by the same amount as the piston stroke and that is twice the 26~4~
diameter of a circle 90 shown in FIG. 8. The center 61 of the crank pin 60C describes the circle 90 on the piston-piston rod assembly 70 as it reciprocates.
The circle 90 is shown projected on the crank journal AYE of the crank 30C as a circle 94 having a center 102. Center point 92 and center 102 are aligned when the piston-piston rod assembly 70 is centered at mid stroke. The center 102 of the circle 94 is the 3 center of rotation of the crank 30C.
The center of rotation 102 of the crank is projected to AYE and the projections of the center 92 at its two extremes of travel are shown at AYE and 92B. At mid stroke the projection of center 92 coincides with AYE. 3 As shown in these diagrams, as the piston moves upwardly, the center-point 92 of connector 28C describes a circle relative to crank pin center 61 while it reciprocates with piston-piston rod assembly 70 along lines 86 and I The circle described by cenSerpoint 92 relative to crank pin center 61 is of the same diameter as circle 90. As crank pin center 61 orbits crank center of rotation 102, connector center point I
orbits crank pin center 61 with the same angular velocity but in the opposite direction. The resulting additive motion of center point 92 is a linear movement of twice I
~2;2~47 diameter 90 or as projected the distance between AYE and 92B. The velocity of center point 92 and likewise the - piston-piston rod assembly 70 is twice the velocity of crank pin center 61 in the linear direction along the lines 86 and 88.
As can be understood from this diagram, the orb tying action takes place to permit reciprocation of the piston while the crank is held for rotation about its central axis, with the crank pin 60C rotating in one direction while connector 28C rotates in the opposite direction. However, there is a possible discontinuity of motion when the piston-piston rod assembly 70 is centered at mid stroke.
At the center of the stroke, the connector has a second degree of freedom permitting it to rotate in the same direction as the crank with its center of velocity equal to Nero. This discontinuity is corrected by a crank-piston interface to insure continuity of direction, velocity and acceleration through this point. The interface is achieved by a crank to piston assembly interface such as a cam-slider or a gear interface.
At mid stroke when center point 92 of connector 28C
is aligned with center of rotation 102 as projected on AYE, it is possible for connector 28C to be driven by ~2;~6~7 the crank pin 60C to rotate wealth the same angular velocity and in the same direction as crank pin 60C, resulting in a zero movement and a zero linear velocity of center point 92 and likewise forpiston-piston rod assembly 70.
There are two possible sets of movement at the center of the stroke which are: (1) the crank rotates in one direction, the connector rotates in the opposite direction and the piston assembly is oscillating moving twice the velocity of the center of the crank pin or the same velocity of the center of the connector and (2) the crank rotates in one direction, the connector rotate sin the.same...di.rection and the piston assembly has zero velocity as does the center of tube connector.
The cam-cam follower interface, such as a cam slider and/or gear interface, is between the crank and piston assembly to insure continuity of movement through the center ox the stroke since there are two degrees of freedom.
This occurs because the center of rotation of the connector coincides with the center of rotation of the crank SO that the orbiting of the crank pin about the center of rotation ox the crank only causes rotation of the connector without linear motion, thus the inertia driving the crank or the rotary force imposed by other 3L2Z~ 7 pistols which may be in a power stroke does not move the piston to its ignition point but instead it is left centered at id stroke In the embodiment of FIG. 7 to prevent this discontinuity at start ups and at low Rums, pinion gears portions AYE and 80B engage with complimentary teeth on similar rack gear portions AYE and ~2B at mid stroke.
Rack gear portions AYE and 82B are integral of or attached near the center edges of piston-piston rod assembly 70 while the pinion gears portion AYE and 82B
are located on the sides of crank journals AYE and 59B
that are adjacent to piston-piston rod assembly 70.
From FIG. 8, one location for pinion teeth (not shown in FIX. 8) would be on a circle twice diameter 94 on the inside face of crank journal AYE and adjacent to the point of intersection 92 and guy. This will match pinion teeth velocity in the direction of lines I and 88 with the velocity of rack gear portions 82B. Gear interface at mid stroke would constitute a true rack and pinion engagement. However, a modified rack and pinion gear interface is superior for positions on either side of mid stroke, since Or = Up Senate where Or Velocity of rack, Up = Pitch velocity of pinion gear AYE or JOB
and T is the angle the pinion gear makes with a core-sponging rack AYE or 82B with T = 90 at mid stroke when ~.~26~
the pinion gear is in contact with its corresponding rack. True rack and pinion action is actually approxi~
- mated until T varies significantly from 90 but is within 10 percent of true driver-driver rack and pinion action near mid stroke. The linear velocity in directions of line 86 and 88 for the pinion gears at described point is at all times the same as piston-piston rod assembly 70.
While gears are described as the means for controlling the continuity of motion through mid stroke, other means may be used. A cam slider mechanism as shown in FIGS. 15 and 16 is one of them. Another is the cam slider mechanism shown in FIGS. 18 and 19 where the point of contact between the cam lobe and the cam follower is of a velocity twice that of the center of the crank pin in the direction of oscillation of the piston-piston rod assembly. In addition the modified rack and pinion described may have modification to their position Andre change in tooth profile to the extent of being more cam slider than true involute. Any mechanism resulting in crank-piston rod interface that causes the motion of the piston-piston rod assembly to have a velocity that is twice that of the center of the crank pin's velocity in the axis of oscillation of the piston-piston rod assembly through a I
predetermined distance of mid stroke may be used.
Generally the inertia forces of the piston assembly except during start and low Rums will carry itself through mid stroke with no need for a positive interface at the point of discontinuity.
In FIG. 9., there is shown a simplified sectional view of a piston-piston rod assembly AYE mounted within a cylinder 12C. A diesel fuel injector 3~C is mounted to inject fuel into the cylinder and a water chamber 39 communicates with the interior of the cylinder to pro-vise cooling. Lubrication inlets 106 and 108 are pro-voided to lubricate the piston-rod assembly 20B.
Lubrication inlets 106 and 108 located adjacent to the skirts and the piston rods and removed from the combustion chamber provide forced oil lubrication to the surfaces encountering side thrust forces that are generally associated with piston skirts in a conventional engine. Since location and magnitude of side thrust on the cylinder walls 12C is dependent largely on the position of connector 28~, the forced oil lubrication should extend from the center of crank 30D in each affection a minimum of one-half the piston stroke where the piston rod 20B and cylinder 12C are in contact. Additional inlets or oil grooves may be used for more even lubrication.
~L226~f~7 This lubrication arrangement has the advantages of:
(1) providing an effective lubricating film to reduce friction between the piston rod 20B and cylinder walls 12C in an area sufficiently removed from the high temperatures of the combustion chamber; and (2) permitting normal piston length to be shortened since piston skirts are no longer necessary to resist piston side thrust.
In the embodiment of FIG. 9, there is only one piston on one side of the piston rod but other pistons may be connected to the crank 30D through separate connectors such as 28D for the rod 20B. In operation, the piston EYE is driven outwardly by the explosion of diesel fuel, causing the connector 28D to move forward (to the left in FIG. 9) so that the crank pin 60D changes position within the rod by rotating the connector 20B
and this causes the crank 30D to rotate about its center. The kinetic energy of a flywheel, or in the case of a multi-cylinder engine, the kinetic energy of the flywheel and the power stroke of other pistons then continue the rotation of the crank so as to bring the piston back into a compression portion of the cycle at the end of which the diesel fuel is ignited and it returns back in a drive portion of its cycle.
~ZÇ;~4~7 This sequence is illustrated better by ERGS 10-13. As shown in FIG. 10, the piston EYE is moving forward after an explosion within cylinder 12C and the - crank pin 60D is rotating in a counter-clockwise direction from its three o'clock position toward its twelve o'clock position as the piston EYE, piston rod 20B and center of the connector move to the left.
In FIG. 11, the crank pin 60D is in the twelve o'clock position, having rotated the crank 30D and the connector 28D. In FIG. 12, the crank pin 60D is in its nine o'clock position, with the piston EYE completing its power stroke and being at its leftmost extreme. The crank 30D has now rotated counterclockwise through a hundred and eighty degrees and the crank pin 60D has orbited counterclockwise through a corresponding one hundred and eighty degrees with the rotation of the connector 28D through one hundred and eighty clockwise degrees.
In FIG. 13, the crank pin 60D has now rotated to its six o'clock position and the piston EYE is starting back in its compression portion of the cycle. This process continues through successive cycles so as to turn the crank 30D.
The workings of FIG. 9 through FIG. 13 applies equally for a single crank engine with one or multiple ~226~L~7 piston-piston rod assemblies as so described in FIGS. 8 and 9. Likewise, the s;ngle~piston rod embodiment of FIG. 9 will generally use a crank-piston rod interlace to carry it through mid stroke as so described from FIGS.
7 and 8. Conventional crankshaft counterweights and balancing would generally be desirable for either the piston rod assembly or the piston-piston rod assembly with either one or multiple connectors.
In FIG. 14, there is shown still another embodiment of the engine loan having a piston-piston rod assembly 70B with two pistons 32F and 32G mounted within different cylinders 12D and EYE for reciprocation therein to move a common piston rod 20C back and forth within the crankcase 16B. The piston rod 20C has a central portion with two connectors EYE and 28F mounted side by side along the line transverse to the line of motion of the piston-piston rod assembly 70B, each driving a corresponding one of the crank pins EYE and 60F
of the corresponding cranks EYE and 30F.
The internal gear and pinion mischances 82~, 82D, 80C and 80D are mounted so that the cranks EYE and 30F
rotate with continuity through mid stroke. In the embodiment of FIG. 14, the cranks may be connected to a single output shaft 68 through a mechanism described and shown in FIG. 6 so that cranks EYE and 30F rotate ~.~26~l~7 synchronized in opposite directions, with the crank EYE
and web 58C rotating in a counterclockwise direction and crank 30F and web 58D in a clockwise direction. With - this mechanism, the inertia forces are balanced as in the embodiment of FIG. 1 but with a more compact engine.
Two cycle scavenging using parts AYE, 53B, AYE and 55B
is conventional. Valves may also be used.
The embodiment of FIG. 14, like that of FIG. 1, has essentially no side thrust since the transverse forces of the connectors EYE and 28F on piston-piston rod assembly 70B oppose each other. Unlike Foggily, the embodiment of FIG. 14 can be completely balanced using webs 58C and 58D, since the linear motion, velocity and acceleration of the piston piston rod assembly 70B can be expressed as a simple sine-cosine function based on crank rotation just as the linear motion of webs 58C
and 58D.
The embodiment of FIG. AL, like conventional connecting rod engines, requires an additional function based on the ratio of connecting rod length to the crank radius. The simple sine-cosine movement of piston-piston rod assembly 70B unlike conventional connecting rod engines, gives the embodiment (FIG. 14) such advantages as: (1) ease in balancing; (2) slower piston velocity per degree crank rotation during injection, ~LZ%6~
thus permitting improved burning or faster diesel RPM;
and 53) a more compact engine.
In FIGS. 15 and 16, still another embodiment of - engine is shown which includes two aligned piston-piston rod assemblies 70C and 70D, each of which is substantially the same as the embodiments of FIGS. 7 and 8. They are mounted to cranks, each of which is substantially the same as the connector-crank assemblies 72 in FIGS. 7 and 8, but the piston-piston rod asset-bites 70C and 70D are aligned with each other so that two of the pistons 32I and 32J share a common cylinder and common fuel injector 36G.
In this embodiment, two parallel cranks are provided and synchronized in their rotation so their respective piston-piston rod assemblies 70C and 70D
reciprocate, with pistons 32I and 32J moving together and then apart in compression and expansion strokes within the same chamber The two parallel cranks may be synchronized in either the same direction or in opposite direction of rotation. If synchronized in opposite directions, the cranks in the embodiment of FIGS. lo and 16 may be connected to the single output shaft 68 through a mechanism as described in FIG. 6. If synchronized in the same direction, the cranks it the embodiment of FIGS. 15 and 16 may be connected to a ~L2Z6~ 7 single output shaft through a mechanism similar to FIG.
6 but where the gears AYE and 64B are replaced by post-live drive pulleys and then connected by a positive - drive belt.
Vibrations are easily minimized in the embodiment of FIGS. 15 and 16 since the cranks 30G and 30H may be synchronized so that the momentums of piston-piston rod assemblies 70C and 70D oppose each other. This leaves only the balancing of connector 28G and 28H and the crank pin 60G and 60H left. Since their momentums Oppose each other in the direction of oscillations, only minor transverse vibrations need attention. The transverse vibrations are small enough to be disregarded but may be corrected with crank counterweights.
In FIG, 15, there is shown an embodiment with cranks 30G and 30H rotating counterclockwise and using cam slider mechanisms EYE, EYE, 80F and 82F.
Cam slider portion EYE is rigidly attached or is an integral part of crank 30G as us portion 80F on crank 30H. Portions 80~ and 80F lead crank pins 6QG and 60H
respectively by about 90 degrees. Cam slider portions EYE and 82F are mounted rigidly or as integral parts of piston-piston rod assemblies 70C and 70D respectively.
The position of cam slider portions EYE and 82F on piston-piston rod assemblies 70C and 703 is such that at Skye mid stroke, portions EYE and 80F, which lead crank pins 60G and 60H by about 1/4 turn, are in contact with portions EYE and 82F and the sliding action exert a force radially out from crank centers from portions EYE
and 80F providing force to portions EYE and 82F in the direction of piston-piston rod oscillation.
This mechanism insures at mid stroke that the piston rod assemblies do no lag behind the crank but does not keep them from running ahead of the crank. The control mechanism of FIGS. 7-14 and 18 and 19 on the other hand disciplines the piston rod assembly from either lagging behind or running ahead. however, the embodiment of FIGS. 15 and 16 may just as easily utilize the modified rack and pinion gear mechanism to insure proper movement through mid stroke. To further reduce cost, the embodiment of FIGS. 15 and 16 may utilize neither mechanism, especially if using a compressed air starter system, despite certain limitations. Any one of the cam slider interface, the gear interface or no interface could likewise be used in FIG. 14 an in FIG.
9 for the piston rod assembly or for a piston-piston rod assembly.
Piston-piston rod assemblies 70C and 70D in the embodiment of FIGS. 15 and 16 experience side thrust forces. Lubrication inlets AYE, 106B, AYE, and 108B
I
provide forced oil lubrication at those surfaces in the manner described in FIG. 9.
To insure proper lubrication, a forced oil system - provides oil under pressure through the crank, into the crank pin, to the outer surfaces of the crank pin in the same manner that the conventional engine lubricates the rod bearings. The forced oil lubricates the surfaces in contact where crank pin 60C rotates in mating hole 84C in connector 28C in FIGS. 7 and 8. In FIG. 17, the embody-mint extends the lubrication from hole 84D in connector 28K through passage 110 to oil outlet 112 to provide lubrication between outer surfaces of the connector and the piston rod housing that it rotates in. Outlet 112 will be in advance of the connector surface receiving the power stroke.
In FIGS. 18 and 19 there is shown another embodiment of engine which is similar in many respects to the engine of FIGS. 15 and 16 but includes as an interface means a novel cam slider mechanism 80G, 80~, 82G and 82H that is functionally similar to the rack and pinion interface AYE, 80B, AYE and 82B FIGS. 7 and 8). The parts of the embodiment of FIGS. 18 and I that are the same as those of FIGS. 15 and 16 have the same reference numbers.
I
The engine of FIGS. 18 and 19 includes two piston-piston rod assemblies EYE and 70F, each ox which is substantially the same as the embodiment of FIGS. 7 and - 8. They are mounted to cranks, each of which is substantially the same as the connector-crank assemblies 72 in FIGS. 7 and 8, but the piston-piston rod asset-bites EYE and 70F are aligned with each other so that two of the pistons 32M and 32N share a common cylinder and common fuel injector 36J.
inn the embodiment of FIGS. 18 and 19 as in the embodiment of FIGS 15 and 16, two parallel cranks are provided and synchronized in their rotation so their respective piston-piston rod assemblies EYE and 70F
reciprocate, with pistons 32M and 32N moving together and then apart in compression and expansion strokes within the same chamber. The two parallel cranks may be synchronized in either the same direction or in opposite directions of rotation.
If synchronized in opposite directions, the cranks inn the embodiment of FIGS. 18 and 19 may be connected to a single output shaft 68 (FIG. 6). If synchronized in the same angular direction, one crank is 1~0 degrees out of phase with the other so that the two corresponding parts of the pairs of parts that are balanced are moving towards and then away from each .
I 61~7 other, such as or example: (1) crank pins 60I and 60J;
This invention relates to reciprocating piston - engines.
In one class of combustion engines, the engine includes reciprocating pistons which drive an eccentric gaily mounted cam shaft through piston and connecting rods. Such engines are subject to vibrations resulting from periodic unbalanced vertical inertia forces of pistons and connecting rods and lateral inertia forces created by crankshaft counterweights as they rotate. To reduce the effect of this vibration, multiple cylinders are frequently included.
In prior art types of this class of engine, Libra-lions are reduced by increasing the number of cylinders 'i and the length of the connecting rods. I
The prior art engines have several disadvantageSsuch as (1) a large number of cylinders increases costs and complexity, especially in diesel engines; (21 if long connecting rods are used, engine size is increased, I if the rod length to crank radius ratio it `.
decreased, the ratio of inertia forces for the top of the stroke compared to the bottom of the stroke is increased, and the ratio of time that the piston spends in the upper half of the stroke as opposed Jo the lower half is decreased which respectively increases Libra-I;' ~2~4~t' tonal problems, decreases fuel burn time per revolution and limits maximum diesel RPM; and (4) the crankshaft deaccelerates the pistons as they approach the end of each stroke and then reaccelerates them, resulting in high stress on cranks, bearings and other components plus energy robbing friction.
To provide a novel engine which is improved in some respects, the apparatus comprises a piston rod adapted to be reciprocated within an engine with a predetermined stroke length, a crank and a crank pin having a center with the center of the crank pin having a predetermined radius of rotation about an axis of crank rotation; an attaching means connects at least one piston to said piston rod, whereby said rod is driven by said piston in the direction of motion of said piston. A connector means is adapted to be attached at a predetermined location on said connector means to the crank pin, said connector means being rotatable mounted to said piston rod about predetermined center of connector rotation with the distance from the center of rotation of said connector means with respect to said piston rod and the predetermined location of connection to said crank pin being equal to said predetermined radius of crank rota-lion.
Advantageously, said piston stroke length is equal to substantially four times the crank radius, the connector means rotates with the same angular velocity but in the opposite direction as the crank, and there is an interface means between said crank and said piston rod that engage at least a length of surfaces sub Stan-tidally at mid stroke to force continuity of piston rod movement with a component of velocity of the piston rod being twice the velocity of the crank pin center in the direction of oscillation of the piston rod through a predetermined portion of mid stroke. Moreover, the interface means may be a cam slider.
There may be at least first and second combustion chambers, at~least.fi~rst and second-reciprocating pistons adapted to reciprocate in corresponding combustion chambers, at least two crankshafts, connect tying means attached to said reciprocating pistons for driving said two crankshafts as said first and second pistons reciprocate, means connected to said crankshafts for obtaining mechanical power therefrom, said means connected to said first and second reciprocating pistons comprising a piston rod having first and second ends, said piston rod having mounted to it said first piston on said first of its ends and said second piston on said second of its ends for reciprocating motion therewith, said crankshafts each having a different main bearing about which they rotate, each of said crankshafts having different web portions and different erankpins, whereby they are eccentrically mounted to provide a flywheel effect and rotate in opposite directions to each other and lubrication means for applying a lubricant to said piston rod at a location removed from said combustion chambers.
The piston rod includes substantially flat parallel sides, said means for connecting said connector means to Swede piston rod, including internal walls defining a cylindrical aperture extending between said parallel -flat sides, two edges of said parallel flat sides are rigidly fastened to one piston, the opposite two edges of said flat parallel sides being rigidly fastened to a second piston, whereby said first and second piston drives said piston rod in opposite directions, said means fur connecting at least one erankpin includes internal walls defining first and second cylindrical apertures, each of said cylindrical apertures being audited to mount a different connector means, said first and second apertures being aligned with each other in a direction at an angle to the direction of motion of said piston rod, a second piston rod, second means for moving said second piston rod in a reciprocating motion, said second piston rod being aligned with said first piston ~6~L~7 rod, means for connecting a piston to edges of said second piston rod, said means of connecting a piston to said second piston rod being between said second piston rod and said first-mentioned piston rod; a crankcase;
said first and second piston rows each being connected at one end to said piston at its other end to a different crank pin on a different one of said crank shafts, said piston rods and crankshafts being mounted within said crankcase, first and second cylinders mounted outside said crankcase aligned with said piston rods, said cylinders each being on a different end of said piston rod, and said first piston fitting within said first cylinder and said second piston fitting with-in said second cylinder.
The first and second crankshafts are mounted parallel to each other with tube same plane passing through their axes and parallel to said piston rod in a plane perpendicular to the plane of said piston rod. A
first gear is mounted to said first crankshaft for rotation therewith, a second gear mounted to said second crankshaft for rotation therewith, and a shaft mounted for rotation to one of said first and second gears for providing power from said engine. The engine is a two-cylinder diesel engine and includes diesel fuel injection means for injecting diesel fuel into one of ~Z2614~
said cylinders at the end of each compression stroke, vent means for venting exhaust fumes during the power stroke of said pistons, a plenum chamber, vent means connected between each of said cylinders and said plenum chamber for causing air to be moved under pressure into said plenum chamber by said piston during said power stroke, and second vent means communicating between said plenum chamber and said cylinder causing air under pressure to escape from said plenum chamber into said cylinder when said piston is substantially at the end of its power stroke.
The interface means may include rack and pinion gearing in which the pinion drives the rack to a velocity twice that of the crank pin center in the direction of piston rod oscillation; may include gearing in which the crank gear drives the piston rod gear to a velocity twice that of the crank pin center in the direction of piston rod oscillation; and may include a means for imparting motion through a predetermined distance of mid stroke from the crank to the piston assembly wherein the piston assembly achieves its maximum velocity at mid stroke and the maximum velocity is substantially twice the orbital velocity of the center ox the crank pin about the axis of crank rotation.
the above noted and other features of the .
~2~7 invention will be understood more completely from the following detailed description when considered with reference to the accompanying drawings in which:
FIG. 1 is a simplified sectional view of an embodiment of the invention;
FIGS 2-5 are developed views showing the operation of the embodiment of FIG. 1 with a slightly different apparatus;
Fig 6 is a simplified plan view, in section, showing a portion of the embodiment of FIG. l;
FIG. 7 is an exploded perspective view of a portion of another embodiment of the invention;
FIG. 8 is a simplified illustrative view of the embodiment of FIG. 7;
FIG. 9 is a sectioned, simplified elevation Al view of an embodiment of the invention;
FIGS 10-13 are developed views illustrating the operation of the embodiment of FIG. 9;
FIG 14 is an elevation Al view of still another embodiment of the invention;
FIG. 15 is a longitudinally-sectioned, elevation Al view of still another embodiment of the invention;
FIG. 16 is a longitudinally-sectional top view of the embodiment of FIG. 15; and FIX. 17 is a simplified perspective view of a portion of the embodiment of FIG. 7;
FIG. 18 is a longitudinally-sectioned, elevation Al view of still another embodiment of the invention; and FIG. 19 is a longitudinally-sectioned top view of the embodiment of FIG. 18.
In FIG. 1, there is shown a two-cylinder, two-cycle, balanced diesel engine 10 having first and second cylinders AYE and 12B and a crankcase 16. The first and second cylinders AYE and 12B are aligned with each other on common axis which passes through the center of the crankcase 16 for cooperation with a single piston rod 20 therein. Generally, the first and second cylinders AYE and 12B and the axis are vertically oriented but horizontal orientation is possible.
The crankcase 16 includes a housing 18 forming a compartment which supports the first and second cylinders AYE and 12B on opposite sides and has located along a central axis between the first and second cylinders AYE and 12B the single piston rod 20 aligned with the first and second cylinders AYE and 12B so that as the single piston rod 20 moves further into the first cylinder AYE, it moves further out of the second cylinder 12B and vice versa. Extending outwardly from opposite sides of the single piston rod 20 within the housing 18 are two wings, AYE and 22B, each having on its end a corresponding one of the bores AYE and 24B
containing a corresponding one of the bearing shells AYE
and 26B. A first connecting rod 28~ has one end rotatable mounted in the bore AYE for rotation within bearing shell AYE and a second connecting rod 28B has one end mounted within the bore 24B for rotation with the bearing shell 26B.
Eccentrically mounted to the first connecting rod AYE is a first crank AYE and eccentrically mounted to the second connecting rod 28B is a second crank 30B. On the opposite ends of the single piston rod 20 and within the respective cylinders AYE and 12B are conventional pistons 32~ and 32B respectively. The conventional pistons AYE and 32B are mounted so that as one moves toward the crankcase 16, the other moves away from the crankcase 16 so that one of the conventional pistons is compressing air in the case of a diesel engine while the other is being powered by the expanding gas formed after ignition.
In the preferred embodiment, the diesel engine 10 is a two-cylinder diesel engine and consequently the cylinders AYE and 12B include cylinder walls AYE and 34B respectively which receive conventional diesel fuel injectors AYE and 36B respectively. The timing of the fuel injection, air compression and venting it Canaan-~2~6~4~
tonal except that cylinders include corresponding towardly plenum chambers AYE and 38B formed by towardly walls BOA and 40B positioned to ye vented into and from corresponding ones of the cylinders AYE and 12B.
To cause the compression of air in the towardly plenum chambers AYE and 38B and use of the compressed air to aid in exhausting the cylinders AYE and 12B, vent ports are positioned in the cylinder walls AYE and 34B
to communicate between the towardly plenum chambers AYE
and 38B and the corresponding inner chambers of the cylinders AYE and 12B such as shown at AYE and 42B
and AYE and 44B. Vents are also positioned in the cylinder walls AYE and 34B at a position adjacent to the top of the towardly plenum chambers AYE and 38B to communicate between the inner part of the corresponding cylinders AYE and 12B and the portions of the toroldal plenum chambers AYE and 38B most remote from the crankcase 16 such as those shown at AYE and 46B and at AYE and 48B.
The conventional pistons AYE and 32B have a height in the direction of the longitudinal axis sufficient so that when they are in their uppermost position adjacent to the top of the cylinders AYE and 12B, all of the vents ox the cylinder walls AYE and 34B and the towardly plenum chambers AYE and 38B are open and when they are in their lowest position, closest to the crankcase 16, the vents adjacent to the crankcase 16 such as AYE, 42B, AYE and 44B are closed by its corresponding piston but the ones most remote from the crankcase 16 such as at AYE, AYE, 46B and 48B are open. With this structure, as the conventional pistons AYE and 32B move toward the crankcase 16, air is forced at first through both vents and then through the bottom vent in the towardly plenum chambers AYE and 38B and when they reach the position closest to the crankcase 16, the compressed air in the towardly plenum chambers AYE and 38B is released into the cylinders AYE and 12B to aid in exhausting it through the uppermost vents.
Exhaust vents are provided at a location where the rim of the conventional pistons AYE and 32B block them when the pistons AYE and 32B are in a position most remote from the crankcase 16 and permit them to be opened when they are in a position adjacent to the crankcase 16 such as at AYE and AYE for cylinder AYE and 50B and 52B for cylinder 12B. appropriate tubing is provided such as that shown schematically at AYE and AYE
and at 54B and SUB to remove the exhaust fumes when air is being forced into the cylinders AYE and 12B from the towardly plenum chambers AYE and 38B. The valving it conventional and will not be described in this ~226~L~7 application.
The crankshafts AYE and 30~ are each of conventional design and include a web portion AYE and 58B respectively, and a crank pin or crank portion AYE
and 60B respectively, each rotating about a corresponding one of the main bearings AYE and 62B. Of necessity, the web portions AYE and 58B, crank pins or crank portions AYE and 60B are positioned so that their centers of mass are offset from the axis of rotation of the crankshafts AYE and 30B and cause some vibration forces when orbiting about the axis of rotation. The crankshafts AYE and 30B are arranged about the single piston rod 20 on opposite sides thereof within the crankcase 16 and on the same side of the wings AYE and 22B with their web portions AYE and 58B being oriented in the same position with respect to the cylinders AYE
and 12B so as to balance their inertia forces in a direction orthogonal to the single piston rod 20 during rotation.
The crankshafts AYE and 30B are sufficiently heavy to serve as fly wheels, and when they rotate, their web portions AYE and 588, rotate toward the single piston rod 20 and away from the single piston rod 20 at the same time. Thus, the lateral inertia forces cancel between the two crankshafts. Moreover, the conventional ~L2;26~L~7 pistons AYE and 32B and cylinders AYE and 12B are arranged so that one piston is going through the power stroke moving downwardly in an opposite direction with respect to the crankcase 16 as the web portion so as to provide further balancing.
In FIGS. 2-5, there is shown a cycle of operation of the diesel engine 10 illustrating the manner in which the forces are balanced by the crankshafts AYE and 30B
during a cycle The diesel engine 10 shown in FIGS. 2-5 has a slightly different placement of the crankshafts AYE and 30B with respect to the side wings AYE and 22B
and the longer and shorter portions of the piston rod 20 but the principle is the same.
In FIG. 2, there is shown the conventional piston AYE at the end of its compression stroke and at the beginning of its power stroke after injection of the diesel fuel and the conventional piston 32B at the beginning of its intake stroke with the fumes being evacuated by compressed air from the towardly plenum chamber AYE (FIG. 1). In this position, the single piston rod 20 is closest to the cylinder AYE (Fig 1) within the crankcase 16 and the connecting rods AYE and 28B are substantially straight with the web portions AYE
and 58B being furthest from the wings AYE and 22B.
In FIG 3, the diesel engine 10 is shown with the Lo 7 conventional piston AYE about one-half through the power stroke in which it is compressing air in the towardly - plenum chamber AYE (FIG. 1) and the conventional piston 32B is compressing air within the cylinder 12B FIG. 1).
In this position, the wings AYE and 22B of the single piston rod 20 have moved in the direction of the Solon-don 12B (FIX. 1) rotating the web portions AYE and 58B
counterclockwise and clockwise respectively so the inert lie forces of each are toward the single piston rod 20 and cancel each other out within the crankcase 16. This direction of rotation is achieved because of the post-lion of bearings of crank pins AYE and 60B with respect to the main bearings AYE and 62B, the bearing of crank pins AYE and 60B being positioned further from the single piston God 20 than the main bearings AYE and 62B
at the beginning of the power stroke of conventional piston AYE with the single piston rod 20 closest to the cylinder AYE FIG. 1).
In FIG. 4, there is shown the diesel engine lo in a position in which the conventional piston AYE is exhausting fumes and in taking air and the conventional piston 32B is at the end of its compression stroke and the beginning of its power stroke after the injection of diesel fuel. In this position, the single piston rod 20 is closest to the cylinder 12B (FIG. 1) within the . .
26~4~7 crankcase 16 and the web portions AYE and 58B have rotated counterclockwise and clockwise respectively in the direction of the cylinder AYE, with their inertia forces in the direction towards cylinder AYE and opposing the inertia forces of the moving central embodiment (pistons and connecting mechanisms) which has inertia forces in direction towards cylinder 12Bt In FIG. 5, there is shown diesel engine 10 with the conventional piston AYE in the process of compressing air and the conventional piston 32B about one half through its power stroke in which position it is compressing air to the towardly plenum chamber 38B
(FIG, 1). In this position, the web portions and 58B are rotating counterclockwise and clockwise respectively with their inertia forces being outward from the single piston rod 20, thus balancing each other.
From FIGS, 2-5 it can be understood thaw the horizontal forcff~s toward and away from the single piston rod 20 caused by the inertia forces of the crankshafts AYE and 30B with web portions AYE and 58B oppose and thus balance each other while the vertical forces in the direction of the conventional pistons AYE and 32B are such that the inertia forces of crankshafts AYE and 30B
with web portions AYE and 58B oppose the inertia forces . .
I L4~7 ox the moving piston and connecting mechanisms (20, AYE, 22B, AYE, 24B, AYE, 26B, AYE, 28B, AYE, 32B, AYE and JOB). Since these forces oppose there is a minimum of vibration and lost power from vibration in the engine.
In FIG. 6, there is shown a top sectional view of the crankshafts AYE and 30B each mounted to rotate a different one of the gears AYE and 64B. The gears AYE
and 64B are engaged and the gear AYE drives an output shaft 68. In this manner, the crankshafts AYE and 30B
each drive a different one of the gears AYE and 64B in synchronism and output shaft 68 as the crankshafts AYE
and 30B are driven by the connecting rods AYE and 28B
(FIG. 1) engaging the crank pin AYE and 60B to turn the crankshafts AYE and 30B about the main bearings AYE and 62B.
In FIG. 7, there is shown a simplified, fragmentary perspective view of another embodiment of the invention having a unitary piston-piston row assembly 70 and a connector-crank assembly 72. The piston-piston rod assembly 70 reciprocates as part ova reciprocating engine and causes the connector-crank assembly 72 to rotate.
The piston-piston rod assembly 70 includes first and second pistons 32C and 32D and a piston rod AYE. The piston rod AYE is generally shaped as a right regular ~L22~7 parallelopiped having first and second parallel flat sides of equal dimensions, one of which is shown at 74, and curved parallel sides connecting the flat sides and having outer surfaces as cylinders, one of which is shown at 76.
On each side of the piston rod AYE is a corresponding one of the two pistons 32C and 32D
integrally formed therewith and having a generally cylindrical shape, with a major diameter equal to or approaching that of the curved parallel sides 76 and a cylindrical curvature the same as or approaching the curvature of the sides 76. The two pistons are separated by the length of the flat side 74. Centrally located in the piston rod AYE and passing between the flat sides is a cylindrical hole 78 adapted to receive the connector-crank assembly 72.
The piston-piston rod assembly 70 may be of unit construction as described or assembled by connecting pistons to the piston rod with fasteners. Curved surface 76 is in contact with the cylinder walls and absorbs the piston side thrust resulting from the forces of the piston through a connector on to the crank. The piston fit against the cylinder walls is looser than the fit of curved surface 76 receives Jo allow for its thermal expansion. The diameter of the crown of the piston is 26~
shorter than the diameter of the skirt portion by less than ten one-thousandths of an inch. In the preferred embodiment the curved surface 76 receives forced oil lubrication and is the primary surface resisting piston assembly side thrust. The surface 76 is also removed from the normal heat build up found in the combustion chamber.
The connector-crank assembly 72 includes a connector 28C, a crank pin 60C and crank journals AYE
and 59B. The connector 28C is cylindrical and sized to conform to hole 78 which receives it The crank your-nets AYE and 59B include pinion gears portions BOA and 80B on sides adjacent to piston-piston rod assembly 70 which interfaces with complimentary teeth on similar rack gear portions AYE and 82B respectively. Holes 84C
in connector 28C and holes BRA and 84B in crank journals AYE and 59B are sized to receive the cylindrical crank pin 60C. Crank pin 6GC may be rigidly attached or an integral part of journals guy and 59B and rotate freely in connector 28C or may be rigidly attached or an integral part of connector 28C and rotate in crank journals AYE and 59B. The center (axis of crank pin 60C
orbits about the center (axis) of crank journals AYE and 59B with the radius of orbit hereafter referred to as the radius of crank rotation.
When assembled, the connector 28C is within a hole 78 and is carried as a whole in the reciprocating motion of the piston-piston rod assembly 70 while it rotates therein. The crank pin 60C is within the hole 84C of the connector 28C within which it rotates while it orbits about the center of the connector 28C as the connector 28C and the piston-piston rod assembly 70 reciprocate.
This orbit has a radius equal to the radius of rotation of the crank 30C and causes rotation of the crank to impart rotary motion in response to the piston stroke, which is four times the radius of rotation of the crank or four times the radius of the rotation of the crank-pin about the center of the connector.
In FIG. 8, there is shown an illustrative drawing of the piston-piston rod assembly 70 at the bottom of its stroke and connector-crank assembly 72 having centerlines 86 and 88 for the piston-piston rod assembly 70 illustrating its direction ox motion an hidden lines 90 illustrating the motion of the crank pin 60C
with respect to center lines 87 and 8g of the crank 30C~
As shown in this figure, the piston-piston rod assembly 70 reciprocates in a linear direction along the lines 86 and 88. The center point 92 of the connector 28C reciprocates in the same direction by the same amount as the piston stroke and that is twice the 26~4~
diameter of a circle 90 shown in FIG. 8. The center 61 of the crank pin 60C describes the circle 90 on the piston-piston rod assembly 70 as it reciprocates.
The circle 90 is shown projected on the crank journal AYE of the crank 30C as a circle 94 having a center 102. Center point 92 and center 102 are aligned when the piston-piston rod assembly 70 is centered at mid stroke. The center 102 of the circle 94 is the 3 center of rotation of the crank 30C.
The center of rotation 102 of the crank is projected to AYE and the projections of the center 92 at its two extremes of travel are shown at AYE and 92B. At mid stroke the projection of center 92 coincides with AYE. 3 As shown in these diagrams, as the piston moves upwardly, the center-point 92 of connector 28C describes a circle relative to crank pin center 61 while it reciprocates with piston-piston rod assembly 70 along lines 86 and I The circle described by cenSerpoint 92 relative to crank pin center 61 is of the same diameter as circle 90. As crank pin center 61 orbits crank center of rotation 102, connector center point I
orbits crank pin center 61 with the same angular velocity but in the opposite direction. The resulting additive motion of center point 92 is a linear movement of twice I
~2;2~47 diameter 90 or as projected the distance between AYE and 92B. The velocity of center point 92 and likewise the - piston-piston rod assembly 70 is twice the velocity of crank pin center 61 in the linear direction along the lines 86 and 88.
As can be understood from this diagram, the orb tying action takes place to permit reciprocation of the piston while the crank is held for rotation about its central axis, with the crank pin 60C rotating in one direction while connector 28C rotates in the opposite direction. However, there is a possible discontinuity of motion when the piston-piston rod assembly 70 is centered at mid stroke.
At the center of the stroke, the connector has a second degree of freedom permitting it to rotate in the same direction as the crank with its center of velocity equal to Nero. This discontinuity is corrected by a crank-piston interface to insure continuity of direction, velocity and acceleration through this point. The interface is achieved by a crank to piston assembly interface such as a cam-slider or a gear interface.
At mid stroke when center point 92 of connector 28C
is aligned with center of rotation 102 as projected on AYE, it is possible for connector 28C to be driven by ~2;~6~7 the crank pin 60C to rotate wealth the same angular velocity and in the same direction as crank pin 60C, resulting in a zero movement and a zero linear velocity of center point 92 and likewise forpiston-piston rod assembly 70.
There are two possible sets of movement at the center of the stroke which are: (1) the crank rotates in one direction, the connector rotates in the opposite direction and the piston assembly is oscillating moving twice the velocity of the center of the crank pin or the same velocity of the center of the connector and (2) the crank rotates in one direction, the connector rotate sin the.same...di.rection and the piston assembly has zero velocity as does the center of tube connector.
The cam-cam follower interface, such as a cam slider and/or gear interface, is between the crank and piston assembly to insure continuity of movement through the center ox the stroke since there are two degrees of freedom.
This occurs because the center of rotation of the connector coincides with the center of rotation of the crank SO that the orbiting of the crank pin about the center of rotation ox the crank only causes rotation of the connector without linear motion, thus the inertia driving the crank or the rotary force imposed by other 3L2Z~ 7 pistols which may be in a power stroke does not move the piston to its ignition point but instead it is left centered at id stroke In the embodiment of FIG. 7 to prevent this discontinuity at start ups and at low Rums, pinion gears portions AYE and 80B engage with complimentary teeth on similar rack gear portions AYE and ~2B at mid stroke.
Rack gear portions AYE and 82B are integral of or attached near the center edges of piston-piston rod assembly 70 while the pinion gears portion AYE and 82B
are located on the sides of crank journals AYE and 59B
that are adjacent to piston-piston rod assembly 70.
From FIG. 8, one location for pinion teeth (not shown in FIX. 8) would be on a circle twice diameter 94 on the inside face of crank journal AYE and adjacent to the point of intersection 92 and guy. This will match pinion teeth velocity in the direction of lines I and 88 with the velocity of rack gear portions 82B. Gear interface at mid stroke would constitute a true rack and pinion engagement. However, a modified rack and pinion gear interface is superior for positions on either side of mid stroke, since Or = Up Senate where Or Velocity of rack, Up = Pitch velocity of pinion gear AYE or JOB
and T is the angle the pinion gear makes with a core-sponging rack AYE or 82B with T = 90 at mid stroke when ~.~26~
the pinion gear is in contact with its corresponding rack. True rack and pinion action is actually approxi~
- mated until T varies significantly from 90 but is within 10 percent of true driver-driver rack and pinion action near mid stroke. The linear velocity in directions of line 86 and 88 for the pinion gears at described point is at all times the same as piston-piston rod assembly 70.
While gears are described as the means for controlling the continuity of motion through mid stroke, other means may be used. A cam slider mechanism as shown in FIGS. 15 and 16 is one of them. Another is the cam slider mechanism shown in FIGS. 18 and 19 where the point of contact between the cam lobe and the cam follower is of a velocity twice that of the center of the crank pin in the direction of oscillation of the piston-piston rod assembly. In addition the modified rack and pinion described may have modification to their position Andre change in tooth profile to the extent of being more cam slider than true involute. Any mechanism resulting in crank-piston rod interface that causes the motion of the piston-piston rod assembly to have a velocity that is twice that of the center of the crank pin's velocity in the axis of oscillation of the piston-piston rod assembly through a I
predetermined distance of mid stroke may be used.
Generally the inertia forces of the piston assembly except during start and low Rums will carry itself through mid stroke with no need for a positive interface at the point of discontinuity.
In FIG. 9., there is shown a simplified sectional view of a piston-piston rod assembly AYE mounted within a cylinder 12C. A diesel fuel injector 3~C is mounted to inject fuel into the cylinder and a water chamber 39 communicates with the interior of the cylinder to pro-vise cooling. Lubrication inlets 106 and 108 are pro-voided to lubricate the piston-rod assembly 20B.
Lubrication inlets 106 and 108 located adjacent to the skirts and the piston rods and removed from the combustion chamber provide forced oil lubrication to the surfaces encountering side thrust forces that are generally associated with piston skirts in a conventional engine. Since location and magnitude of side thrust on the cylinder walls 12C is dependent largely on the position of connector 28~, the forced oil lubrication should extend from the center of crank 30D in each affection a minimum of one-half the piston stroke where the piston rod 20B and cylinder 12C are in contact. Additional inlets or oil grooves may be used for more even lubrication.
~L226~f~7 This lubrication arrangement has the advantages of:
(1) providing an effective lubricating film to reduce friction between the piston rod 20B and cylinder walls 12C in an area sufficiently removed from the high temperatures of the combustion chamber; and (2) permitting normal piston length to be shortened since piston skirts are no longer necessary to resist piston side thrust.
In the embodiment of FIG. 9, there is only one piston on one side of the piston rod but other pistons may be connected to the crank 30D through separate connectors such as 28D for the rod 20B. In operation, the piston EYE is driven outwardly by the explosion of diesel fuel, causing the connector 28D to move forward (to the left in FIG. 9) so that the crank pin 60D changes position within the rod by rotating the connector 20B
and this causes the crank 30D to rotate about its center. The kinetic energy of a flywheel, or in the case of a multi-cylinder engine, the kinetic energy of the flywheel and the power stroke of other pistons then continue the rotation of the crank so as to bring the piston back into a compression portion of the cycle at the end of which the diesel fuel is ignited and it returns back in a drive portion of its cycle.
~ZÇ;~4~7 This sequence is illustrated better by ERGS 10-13. As shown in FIG. 10, the piston EYE is moving forward after an explosion within cylinder 12C and the - crank pin 60D is rotating in a counter-clockwise direction from its three o'clock position toward its twelve o'clock position as the piston EYE, piston rod 20B and center of the connector move to the left.
In FIG. 11, the crank pin 60D is in the twelve o'clock position, having rotated the crank 30D and the connector 28D. In FIG. 12, the crank pin 60D is in its nine o'clock position, with the piston EYE completing its power stroke and being at its leftmost extreme. The crank 30D has now rotated counterclockwise through a hundred and eighty degrees and the crank pin 60D has orbited counterclockwise through a corresponding one hundred and eighty degrees with the rotation of the connector 28D through one hundred and eighty clockwise degrees.
In FIG. 13, the crank pin 60D has now rotated to its six o'clock position and the piston EYE is starting back in its compression portion of the cycle. This process continues through successive cycles so as to turn the crank 30D.
The workings of FIG. 9 through FIG. 13 applies equally for a single crank engine with one or multiple ~226~L~7 piston-piston rod assemblies as so described in FIGS. 8 and 9. Likewise, the s;ngle~piston rod embodiment of FIG. 9 will generally use a crank-piston rod interlace to carry it through mid stroke as so described from FIGS.
7 and 8. Conventional crankshaft counterweights and balancing would generally be desirable for either the piston rod assembly or the piston-piston rod assembly with either one or multiple connectors.
In FIG. 14, there is shown still another embodiment of the engine loan having a piston-piston rod assembly 70B with two pistons 32F and 32G mounted within different cylinders 12D and EYE for reciprocation therein to move a common piston rod 20C back and forth within the crankcase 16B. The piston rod 20C has a central portion with two connectors EYE and 28F mounted side by side along the line transverse to the line of motion of the piston-piston rod assembly 70B, each driving a corresponding one of the crank pins EYE and 60F
of the corresponding cranks EYE and 30F.
The internal gear and pinion mischances 82~, 82D, 80C and 80D are mounted so that the cranks EYE and 30F
rotate with continuity through mid stroke. In the embodiment of FIG. 14, the cranks may be connected to a single output shaft 68 through a mechanism described and shown in FIG. 6 so that cranks EYE and 30F rotate ~.~26~l~7 synchronized in opposite directions, with the crank EYE
and web 58C rotating in a counterclockwise direction and crank 30F and web 58D in a clockwise direction. With - this mechanism, the inertia forces are balanced as in the embodiment of FIG. 1 but with a more compact engine.
Two cycle scavenging using parts AYE, 53B, AYE and 55B
is conventional. Valves may also be used.
The embodiment of FIG. 14, like that of FIG. 1, has essentially no side thrust since the transverse forces of the connectors EYE and 28F on piston-piston rod assembly 70B oppose each other. Unlike Foggily, the embodiment of FIG. 14 can be completely balanced using webs 58C and 58D, since the linear motion, velocity and acceleration of the piston piston rod assembly 70B can be expressed as a simple sine-cosine function based on crank rotation just as the linear motion of webs 58C
and 58D.
The embodiment of FIG. AL, like conventional connecting rod engines, requires an additional function based on the ratio of connecting rod length to the crank radius. The simple sine-cosine movement of piston-piston rod assembly 70B unlike conventional connecting rod engines, gives the embodiment (FIG. 14) such advantages as: (1) ease in balancing; (2) slower piston velocity per degree crank rotation during injection, ~LZ%6~
thus permitting improved burning or faster diesel RPM;
and 53) a more compact engine.
In FIGS. 15 and 16, still another embodiment of - engine is shown which includes two aligned piston-piston rod assemblies 70C and 70D, each of which is substantially the same as the embodiments of FIGS. 7 and 8. They are mounted to cranks, each of which is substantially the same as the connector-crank assemblies 72 in FIGS. 7 and 8, but the piston-piston rod asset-bites 70C and 70D are aligned with each other so that two of the pistons 32I and 32J share a common cylinder and common fuel injector 36G.
In this embodiment, two parallel cranks are provided and synchronized in their rotation so their respective piston-piston rod assemblies 70C and 70D
reciprocate, with pistons 32I and 32J moving together and then apart in compression and expansion strokes within the same chamber The two parallel cranks may be synchronized in either the same direction or in opposite direction of rotation. If synchronized in opposite directions, the cranks in the embodiment of FIGS. lo and 16 may be connected to the single output shaft 68 through a mechanism as described in FIG. 6. If synchronized in the same direction, the cranks it the embodiment of FIGS. 15 and 16 may be connected to a ~L2Z6~ 7 single output shaft through a mechanism similar to FIG.
6 but where the gears AYE and 64B are replaced by post-live drive pulleys and then connected by a positive - drive belt.
Vibrations are easily minimized in the embodiment of FIGS. 15 and 16 since the cranks 30G and 30H may be synchronized so that the momentums of piston-piston rod assemblies 70C and 70D oppose each other. This leaves only the balancing of connector 28G and 28H and the crank pin 60G and 60H left. Since their momentums Oppose each other in the direction of oscillations, only minor transverse vibrations need attention. The transverse vibrations are small enough to be disregarded but may be corrected with crank counterweights.
In FIG, 15, there is shown an embodiment with cranks 30G and 30H rotating counterclockwise and using cam slider mechanisms EYE, EYE, 80F and 82F.
Cam slider portion EYE is rigidly attached or is an integral part of crank 30G as us portion 80F on crank 30H. Portions 80~ and 80F lead crank pins 6QG and 60H
respectively by about 90 degrees. Cam slider portions EYE and 82F are mounted rigidly or as integral parts of piston-piston rod assemblies 70C and 70D respectively.
The position of cam slider portions EYE and 82F on piston-piston rod assemblies 70C and 703 is such that at Skye mid stroke, portions EYE and 80F, which lead crank pins 60G and 60H by about 1/4 turn, are in contact with portions EYE and 82F and the sliding action exert a force radially out from crank centers from portions EYE
and 80F providing force to portions EYE and 82F in the direction of piston-piston rod oscillation.
This mechanism insures at mid stroke that the piston rod assemblies do no lag behind the crank but does not keep them from running ahead of the crank. The control mechanism of FIGS. 7-14 and 18 and 19 on the other hand disciplines the piston rod assembly from either lagging behind or running ahead. however, the embodiment of FIGS. 15 and 16 may just as easily utilize the modified rack and pinion gear mechanism to insure proper movement through mid stroke. To further reduce cost, the embodiment of FIGS. 15 and 16 may utilize neither mechanism, especially if using a compressed air starter system, despite certain limitations. Any one of the cam slider interface, the gear interface or no interface could likewise be used in FIG. 14 an in FIG.
9 for the piston rod assembly or for a piston-piston rod assembly.
Piston-piston rod assemblies 70C and 70D in the embodiment of FIGS. 15 and 16 experience side thrust forces. Lubrication inlets AYE, 106B, AYE, and 108B
I
provide forced oil lubrication at those surfaces in the manner described in FIG. 9.
To insure proper lubrication, a forced oil system - provides oil under pressure through the crank, into the crank pin, to the outer surfaces of the crank pin in the same manner that the conventional engine lubricates the rod bearings. The forced oil lubricates the surfaces in contact where crank pin 60C rotates in mating hole 84C in connector 28C in FIGS. 7 and 8. In FIG. 17, the embody-mint extends the lubrication from hole 84D in connector 28K through passage 110 to oil outlet 112 to provide lubrication between outer surfaces of the connector and the piston rod housing that it rotates in. Outlet 112 will be in advance of the connector surface receiving the power stroke.
In FIGS. 18 and 19 there is shown another embodiment of engine which is similar in many respects to the engine of FIGS. 15 and 16 but includes as an interface means a novel cam slider mechanism 80G, 80~, 82G and 82H that is functionally similar to the rack and pinion interface AYE, 80B, AYE and 82B FIGS. 7 and 8). The parts of the embodiment of FIGS. 18 and I that are the same as those of FIGS. 15 and 16 have the same reference numbers.
I
The engine of FIGS. 18 and 19 includes two piston-piston rod assemblies EYE and 70F, each ox which is substantially the same as the embodiment of FIGS. 7 and - 8. They are mounted to cranks, each of which is substantially the same as the connector-crank assemblies 72 in FIGS. 7 and 8, but the piston-piston rod asset-bites EYE and 70F are aligned with each other so that two of the pistons 32M and 32N share a common cylinder and common fuel injector 36J.
inn the embodiment of FIGS. 18 and 19 as in the embodiment of FIGS 15 and 16, two parallel cranks are provided and synchronized in their rotation so their respective piston-piston rod assemblies EYE and 70F
reciprocate, with pistons 32M and 32N moving together and then apart in compression and expansion strokes within the same chamber. The two parallel cranks may be synchronized in either the same direction or in opposite directions of rotation.
If synchronized in opposite directions, the cranks inn the embodiment of FIGS. 18 and 19 may be connected to a single output shaft 68 (FIG. 6). If synchronized in the same angular direction, one crank is 1~0 degrees out of phase with the other so that the two corresponding parts of the pairs of parts that are balanced are moving towards and then away from each .
I 61~7 other, such as or example: (1) crank pins 60I and 60J;
(2) connectors 28I and 28J; (3) cam lobes 80G and 80H;
and (4) piston-piston rod assemblies EYE and 70F
respectively. One crank pin is at the 12 o'clock position as shown in the embodiment of FIG. 11 when the other crank pin is at the 6 o'clock position as shown in the embodiment of FIG. 13. To synchronize parallel parts in the same angular direction, the cranks in embodiment of FIGS. 18 and 19 are connected to a single LO output shaft through positive drove pulleys and then connected by a positive drive belt.
To reduce vibrations in the embodiment of FIGS. 18 and lo, the cranks 30I and 30J are synchronized so that the momentums of piston-piston rod assemblies EYE
and 70F oppose each other. This leave only the balancing of connectors 28I and 28J, crank pins 60I and 60J and cam lobes 80G and 80H left. Since their momentums oppose each other in the direction of oscillations, only minor transverse vibrations need attenuation. The transverse vibrations are quite small and may be disregarded or corrected with crank counter-weights.
To insure proper movement of connectors 28I and 28J through mid stroke, the cam-cam follower mechanism includes cam lobes 80G and 80H on cranks 30I and 30J and ~L226~L47 cam followers 82G and 82H on piston-piston rod assemblies EYE and 70F respectively. An endless multitude of cam-cam follower profiles and locations may -- be described and used to limit the connectors to one set of motion to insure smooth continuous movement through mid stroke For example, cam followers 82G and 82H are rigidly attached or are integral parts of piston-piston rod assemblies EYE and 70F respectively with their contact edges transverse to the axis of oscillation of the piston assemblies.
Cam lobes 80G and 80H are of circular profile for those portions that do contact the cam followers through a predetermined distance of mid stroke. The cam lobes 80G and 80~ are rigidly attached or are integral parts of the cranks 30I and 30J. The axes of symmetry used to generate the cylindrical profile portions of the cam lobes 80G and 80H, hereafter referred to as the cam lobes centers, are located on lines extending radially out from the axes of rotation of the cranks 30I and 303 through the geometric centers of crank pins 60I and 60J
respectively with the radial distances of the cam lobes centers from the cranks axes of rotation within a stationary housing 18 (FIG. 1) being twice that of the crank pins' orbital radii about the axes of rotation of the cranks.
Since the points of engaclement on each cam lobe are on a circular profile around the cam lobe center and the points of engagement on each cam follower are - transverse to the axis of oscillation of the piston assemblies, then the points of engagement on each cam lobe will be in contact with the cam follower only when the line from the point of engagement to the cam lobe center is parallel to the axis of oscillation of the piston assemblies and during contact will thus have a velocity of zero with respect to the cam lobe center in the direction parallel to the axis of oscillation of the piston assemblies.
The cam lobes thus impart or restrict the cam followers to the velocities of the centers of the cam lobes parallel to the linear velocities of oscillation Go the piston assemblies. The angular velocities of the center of the cam lobe 80G and the center of crank pin 60I about the axis of rotation of crank 30I within a stationary housing are the same and since the radial distance from the center of cam lobe 8QG to the axis of rotation is twice that of the orbital radius of crank pin 60I about the axis of rotation, then the velocity of the center of cam lobe 80G in the direction parallel to the axis of oscillation of the piston assembly EYE with respect to the housing, is twice that of the center of crank pin 60I in the same direction, and thus is the same as the center of connector 28I. The tangential velocities of the points of engagement on the cam lobes 80G and 80H of the piston piston rod assemblies parallel to the linear velocity of the oscillation of the piston with respect to the housing is thus twice that of the centers of crank pins 60I and 60J respectively and thus the same as the centers of the connectors 28I and 28J
respectively.
This is best shown in the embodiment of FIGS. 7 and 8, which illustrates that the center of the connector roves at twice the velocity as the center of the crank pin in the direction of oscillation of the piston-piston rod assembly. Finally, since the velocity of the center of cam follower lobe 80G in the direction parallel to the axis of oscillation of the piston-piston rod assembly is the same as both the center of connector 28I and the contacting points of engagement on cam lobe 80G in the same said direction, then cam lobe 80G
I restrict cam follower BUG and likewise piston assembly EYE and connector 281 to one set of motions through mid stroke which is twice the velocity of the center of crank pin 60I in the above same said direction. The above applies likewise to cam lobe 80H, crank pin 60J, crank 30J, connector 28J, cam follower EYE and piston assembly ~;26~f17 70F, thus permitting the cam-cam followers to eliminate the possible set of motions where the piston assemblies remain stationary while the cranks turn as describe in FIGS 7 and 8.
The relationship between the velocity of the cam lobe and the crank pin may also be described as: Vat =
2Vcp since Vcp = Rcpw~ vat = RC1W, and RC1 = 2RCp where Vat is the rotational velocity of the center ox the cam lobe Vcp is the rotational velocity of the center of the crank pint W is the angular velocity of the crank with respect to a stationary housing and thus likewise the angular velocity for the cam lobe center and crank-pin center, and RC1 is the radius from the crank axis to the cam lobe center which is twice Rap which is the radius from the crank axis of rotation in the housing to the crank pin axis center.
The specific cam lobe described was of a circular profile for those portions that engaged with the cam follower and the cam follower had points of engagement transverse to the axis of piston assembly oscillation.
The point of generation of the cam lobe's circular profile referenced as the cam lobe center, was described as having twice the radius of the crank pin's orbital radius about the crank center of rotation and being on the line extending radially out from the center Lyle of crank rotation and continuing through the crank pin center.
Since the cam lobe center and crank pin center are on the same line extending out from the crank center of rotation, then also Vclsin.T = 2VcpSin.T. where lot" is the angle the crank makes at the time being considered with respect to the axis of oscillation of the piston assembly in a counterclockwise direction with zero degrees being defined with the piston assembly at its extreme right of travel, and "T" will be 90 degrees at mid stroke when the piston assembly is moving in one direction along the axis of oscillation and "T" will be 270 degrees at mids~roke when the assembly moves in the opposite direction. Also Vc = 2VcpSin.T. where Vc is the velocity of the center of the connector since the connector is connected to the crank pin and rotates around the crank pin axis with an equal but opposite angular velocity and has a radius from the crank pin axis to the connector center of rotation that is equal to the radius from the crank axis of rotation to the crank pin axis.
Since the velocity of the center of the connector is restricted to along the axis of piston assembly oscillation, the component velocities of the crank pin around the crank center and the connector around the 3L22~4~7 crank pin center are equal and additive in the direction of oscillation but cancel in the transverse direction - wiving Vc = 2VcpSin.T. Finally, Vclsin.T. = Vc because - both equal 2vcpsin-T- and since the cam lobe profile us circular around the cam lobe center and the cam followers profile is transverse to the axis of oscillation, the points of engagement of the cam lobe will also exhibit velocity 2vcpSin.T. as they come in contact with the cam follower. This is true because the comma lobe's points of engagement that are in contact with thy cam follower are always the same distance from the cam lobe center/ thus their velocity with respect to the cam lobe center is zero since velocity is the change of distance with respect to time. The cam will thus engage the cam followers as it approaches mid stroke and insure through mid stroke that the piston rod assembly moves with continuity at the continuing velocity of 2VcpSin.T.
In the embodiment of FIGS. 18 and 19, the crank pins 60I and 60J, and cam lobes 80G and 80H are Sheehan at their 12 o'clock position with T equal to 90 degrees. In this position the cam lobes 80G and 80~ are sandwiched between cam followers 82~ and 82H. The diameter of the circular profile of the cam lobe that contacts the cam Followers is slightly less than the distance between the cam followers to closely discipline I
the movement ox the piston-piston rod assembly through mid stroke.
The cam follower mechanism may have various locations but a preferred location is with the center of the cam lobe on the line extending radially out from the center of the crank rotation and continuing through the crank pin center. This location is advantageous in ease of construction to not only keep the piston-piston assembly from lagging behind the crank during starts but also to keep it from running ahead of the crank while the engine is operating under a load. The duration of the cam-cam follower interface is generally necessary only for about 25 degrees before mid stroke to about 25 degrees after mid stroke to guard the connector against its second degree of freedom as described in embodiment FIGS. 7 and I
The cam-cam follower mechanism described in embodiment 18 and 19 was a specific example. The velocity that the cam lobe constrained on the cam follower was twice the velocity of the center of the crank pin in the direction parallel to the axis of piston assembly oscillation where the velocity of the cam lobe center with respect to the axis of crank rotation was twice that of the crank pin center in the same said direction while the velocity of the cam lobe in contact with the cam follower with respect to the cam lobe center was zero in same said direction.
The location of the cam lobe center and the profiles of the cam lobe can be unlimited where the velocity of the cam lobe center with respect to the crank's axis of rotation in the direction of piston assembly oscillation is greater or lesser than in the example provided the cam lobe profile is such that its velocity of its contacting points of engagement with respect to the cam lobe center in the direction of piston assembly oscillation is lesser or greater and results in a velocity of twice that of the crank pin center with respect to the crank's axis of rotation in the same said direction. Also, the cam follower profile need not be transverse to the axis of piston assembly oscillation as long as the cam lobe center and/or profile is such that it will still constrain the cam follower and likewise the piston-piston rod assembly to a velocity of twice the center of the crank pin in the direction parallel to piston assembly oscillation.
The possible cam follower profiles and cam profiles could be various utilizing straight lines, circles, arcs, involutes, or even polynomial curves provided they constrain the piston assembly to a velocity that is twice the velocity of the center of .
~L~Z~L4~
the crank pin in the direction parallel to the axis of piston assembly oscillation through a predetermined distance of mid stroke. Any control mechanism (gear, cam slider, cam follower inclusive) that through a predetermined distance of mid stroke imparts or restrains motion from the crank to the piston assembly that is sinusoidal and where the piston assembly achieves its maximum velocity at mid stroke and where that maximum velocity is substantially twice the orbital velocity of the center of the crank pin about the axis of crank rotation may be used.
Although one specific cam-cam follower profile has been described for the embodiment of FIGS. 18 and 19, a large number of cam-cam follower profiles can be used.
Such profiles range from a group of cam slider mocha-nisms with primarily a sliding contact between the cam and the cam followers to a group where the action between the cam and cam follower is a rolling contact.
The action between the cam and cam followers may be involute in nature and yet satisfy the equation 2Vcpsin.T.
Rack and pinion gearing is also included for the purposes of this application, and true rack and pinion gearing may satisfy the equation 2Vcp jut would not be inclusive of the sine T function unless modified for Lo the sine function. All of these mechanisms are within the meaning of cam and cam follower as used in this description. However, gearing would sufficiently satisfy the equation 2vcpsin-T for a small portion of mid stroke since Senate =1 when T = 90 degrees but for an inter-face of up to 30 degrees before and after exact mid-stroke the preferred embodiment is a cam-cam follower imparting motion satisfying 2vcpSin.T including the subset of cams that are involutes or gear portions the conjugate surfaces of which are modified to satisfy the relation 2vcpsin.T~ where again Vcp is the velocity of the center of the crank pin and 2vcpSin.T is twice the component velocity of the crank pin on the axis of oscillation of the piston-piston rod assembly.
In the embodiment of FITS. 18 and 19 the engine includes main bearing housings AYE, AYE, lob and 122B
FIG. 19) and crank lips AYE, AYE, 123B and 124B
that maintain the crank centered between main bearing housings AYE, AYE, 121B and 122R. The housings per-mix the connectors 28I and 28J and cranks 301 and 30J to be assembled into the piston-piston rod assemblies EYE
and 70F by passing them through the openings in crankcases EYE and 16F into which the main bearing housings are assembled thereafter. housings AYE and AYE extend into crankcase EYE and serve to reduce the ,.:
ISLE
flexural stress on crank 30I and crank pin 60I thus permitting smaller crank end crank pin dimensions Housings 121B and 122B do likewise. Piston pins AYE, 120B, 120C and 120D serve as fasteners to connect the pistons with their respective piston-piston rods.
To insure proper lubrication to the embodiment of FIGS. 18 and 19 a forced oil system provides oil under pressure from crankcases EYE and 16F through main bearing housings AYE, AYE, 121B and 122B through cranks 30I and 30J into the crank pins 60I and 60J and to their outer surfaces in the manner that the conventional engine lubricates rod and journal bearings. The forced oil lubricates the surfaces in contact where crank pin 60C rotates in mating hole 84C in connector 28C in FIGS.
7 and 8. The lubrication between the connector and the piston rod housing is as described in the embodiment of FIG. 17.
Piston-piston rod assemblies EYE and 70F in the embodiment of FIGS. 18 and 19 experience side thrust forces Lubrication inlets 106C1 106D, 108C and 108D
provide forced oil lubrication at those surfaces as described in connection with FIG. 9.
Although a two-cylinder diesel engine has been described, obviously other types of engines may incorporate the invention and diesel engines with more cylinders may include the invention. External combustion engines as well as internal combustion engines, air compressors and pumps may also incorporate the invention. Ox course, different cranks with a larger number of crank pins, webs and throws may be necessary.
As can be understood from the above description, the balanced engines of this invention have several advantages, such as: (1) they are economical in con-struction because of their simplicity, particularly when used as a two-cycle cylinder diesel engine since they operate smoothly without a large number of cylinders and expensive fuel injectors; (2) they provide operation with less vibration than unbalanced engines; I they provide operation with less crank stress and friction;
(43 they provide efficiency by reducing the amount of energy used to generate harmonic vibrations rather than useful work; and (5) FITS. 7-16 and FIGS. lB-l9 are more compact than conventional engines.
Although a specific embodiment has been described, many modifications and variations of the embodiments are possible within the light of the above teachings without deviating from the invention. Therefore, it is to be understood that, within the scope of the appending claims, the invention may be practiced other than as I
specifically described.
and (4) piston-piston rod assemblies EYE and 70F
respectively. One crank pin is at the 12 o'clock position as shown in the embodiment of FIG. 11 when the other crank pin is at the 6 o'clock position as shown in the embodiment of FIG. 13. To synchronize parallel parts in the same angular direction, the cranks in embodiment of FIGS. 18 and 19 are connected to a single LO output shaft through positive drove pulleys and then connected by a positive drive belt.
To reduce vibrations in the embodiment of FIGS. 18 and lo, the cranks 30I and 30J are synchronized so that the momentums of piston-piston rod assemblies EYE
and 70F oppose each other. This leave only the balancing of connectors 28I and 28J, crank pins 60I and 60J and cam lobes 80G and 80H left. Since their momentums oppose each other in the direction of oscillations, only minor transverse vibrations need attenuation. The transverse vibrations are quite small and may be disregarded or corrected with crank counter-weights.
To insure proper movement of connectors 28I and 28J through mid stroke, the cam-cam follower mechanism includes cam lobes 80G and 80H on cranks 30I and 30J and ~L226~L47 cam followers 82G and 82H on piston-piston rod assemblies EYE and 70F respectively. An endless multitude of cam-cam follower profiles and locations may -- be described and used to limit the connectors to one set of motion to insure smooth continuous movement through mid stroke For example, cam followers 82G and 82H are rigidly attached or are integral parts of piston-piston rod assemblies EYE and 70F respectively with their contact edges transverse to the axis of oscillation of the piston assemblies.
Cam lobes 80G and 80H are of circular profile for those portions that do contact the cam followers through a predetermined distance of mid stroke. The cam lobes 80G and 80~ are rigidly attached or are integral parts of the cranks 30I and 30J. The axes of symmetry used to generate the cylindrical profile portions of the cam lobes 80G and 80H, hereafter referred to as the cam lobes centers, are located on lines extending radially out from the axes of rotation of the cranks 30I and 303 through the geometric centers of crank pins 60I and 60J
respectively with the radial distances of the cam lobes centers from the cranks axes of rotation within a stationary housing 18 (FIG. 1) being twice that of the crank pins' orbital radii about the axes of rotation of the cranks.
Since the points of engaclement on each cam lobe are on a circular profile around the cam lobe center and the points of engagement on each cam follower are - transverse to the axis of oscillation of the piston assemblies, then the points of engagement on each cam lobe will be in contact with the cam follower only when the line from the point of engagement to the cam lobe center is parallel to the axis of oscillation of the piston assemblies and during contact will thus have a velocity of zero with respect to the cam lobe center in the direction parallel to the axis of oscillation of the piston assemblies.
The cam lobes thus impart or restrict the cam followers to the velocities of the centers of the cam lobes parallel to the linear velocities of oscillation Go the piston assemblies. The angular velocities of the center of the cam lobe 80G and the center of crank pin 60I about the axis of rotation of crank 30I within a stationary housing are the same and since the radial distance from the center of cam lobe 8QG to the axis of rotation is twice that of the orbital radius of crank pin 60I about the axis of rotation, then the velocity of the center of cam lobe 80G in the direction parallel to the axis of oscillation of the piston assembly EYE with respect to the housing, is twice that of the center of crank pin 60I in the same direction, and thus is the same as the center of connector 28I. The tangential velocities of the points of engagement on the cam lobes 80G and 80H of the piston piston rod assemblies parallel to the linear velocity of the oscillation of the piston with respect to the housing is thus twice that of the centers of crank pins 60I and 60J respectively and thus the same as the centers of the connectors 28I and 28J
respectively.
This is best shown in the embodiment of FIGS. 7 and 8, which illustrates that the center of the connector roves at twice the velocity as the center of the crank pin in the direction of oscillation of the piston-piston rod assembly. Finally, since the velocity of the center of cam follower lobe 80G in the direction parallel to the axis of oscillation of the piston-piston rod assembly is the same as both the center of connector 28I and the contacting points of engagement on cam lobe 80G in the same said direction, then cam lobe 80G
I restrict cam follower BUG and likewise piston assembly EYE and connector 281 to one set of motions through mid stroke which is twice the velocity of the center of crank pin 60I in the above same said direction. The above applies likewise to cam lobe 80H, crank pin 60J, crank 30J, connector 28J, cam follower EYE and piston assembly ~;26~f17 70F, thus permitting the cam-cam followers to eliminate the possible set of motions where the piston assemblies remain stationary while the cranks turn as describe in FIGS 7 and 8.
The relationship between the velocity of the cam lobe and the crank pin may also be described as: Vat =
2Vcp since Vcp = Rcpw~ vat = RC1W, and RC1 = 2RCp where Vat is the rotational velocity of the center ox the cam lobe Vcp is the rotational velocity of the center of the crank pint W is the angular velocity of the crank with respect to a stationary housing and thus likewise the angular velocity for the cam lobe center and crank-pin center, and RC1 is the radius from the crank axis to the cam lobe center which is twice Rap which is the radius from the crank axis of rotation in the housing to the crank pin axis center.
The specific cam lobe described was of a circular profile for those portions that engaged with the cam follower and the cam follower had points of engagement transverse to the axis of piston assembly oscillation.
The point of generation of the cam lobe's circular profile referenced as the cam lobe center, was described as having twice the radius of the crank pin's orbital radius about the crank center of rotation and being on the line extending radially out from the center Lyle of crank rotation and continuing through the crank pin center.
Since the cam lobe center and crank pin center are on the same line extending out from the crank center of rotation, then also Vclsin.T = 2VcpSin.T. where lot" is the angle the crank makes at the time being considered with respect to the axis of oscillation of the piston assembly in a counterclockwise direction with zero degrees being defined with the piston assembly at its extreme right of travel, and "T" will be 90 degrees at mid stroke when the piston assembly is moving in one direction along the axis of oscillation and "T" will be 270 degrees at mids~roke when the assembly moves in the opposite direction. Also Vc = 2VcpSin.T. where Vc is the velocity of the center of the connector since the connector is connected to the crank pin and rotates around the crank pin axis with an equal but opposite angular velocity and has a radius from the crank pin axis to the connector center of rotation that is equal to the radius from the crank axis of rotation to the crank pin axis.
Since the velocity of the center of the connector is restricted to along the axis of piston assembly oscillation, the component velocities of the crank pin around the crank center and the connector around the 3L22~4~7 crank pin center are equal and additive in the direction of oscillation but cancel in the transverse direction - wiving Vc = 2VcpSin.T. Finally, Vclsin.T. = Vc because - both equal 2vcpsin-T- and since the cam lobe profile us circular around the cam lobe center and the cam followers profile is transverse to the axis of oscillation, the points of engagement of the cam lobe will also exhibit velocity 2vcpSin.T. as they come in contact with the cam follower. This is true because the comma lobe's points of engagement that are in contact with thy cam follower are always the same distance from the cam lobe center/ thus their velocity with respect to the cam lobe center is zero since velocity is the change of distance with respect to time. The cam will thus engage the cam followers as it approaches mid stroke and insure through mid stroke that the piston rod assembly moves with continuity at the continuing velocity of 2VcpSin.T.
In the embodiment of FIGS. 18 and 19, the crank pins 60I and 60J, and cam lobes 80G and 80H are Sheehan at their 12 o'clock position with T equal to 90 degrees. In this position the cam lobes 80G and 80~ are sandwiched between cam followers 82~ and 82H. The diameter of the circular profile of the cam lobe that contacts the cam Followers is slightly less than the distance between the cam followers to closely discipline I
the movement ox the piston-piston rod assembly through mid stroke.
The cam follower mechanism may have various locations but a preferred location is with the center of the cam lobe on the line extending radially out from the center of the crank rotation and continuing through the crank pin center. This location is advantageous in ease of construction to not only keep the piston-piston assembly from lagging behind the crank during starts but also to keep it from running ahead of the crank while the engine is operating under a load. The duration of the cam-cam follower interface is generally necessary only for about 25 degrees before mid stroke to about 25 degrees after mid stroke to guard the connector against its second degree of freedom as described in embodiment FIGS. 7 and I
The cam-cam follower mechanism described in embodiment 18 and 19 was a specific example. The velocity that the cam lobe constrained on the cam follower was twice the velocity of the center of the crank pin in the direction parallel to the axis of piston assembly oscillation where the velocity of the cam lobe center with respect to the axis of crank rotation was twice that of the crank pin center in the same said direction while the velocity of the cam lobe in contact with the cam follower with respect to the cam lobe center was zero in same said direction.
The location of the cam lobe center and the profiles of the cam lobe can be unlimited where the velocity of the cam lobe center with respect to the crank's axis of rotation in the direction of piston assembly oscillation is greater or lesser than in the example provided the cam lobe profile is such that its velocity of its contacting points of engagement with respect to the cam lobe center in the direction of piston assembly oscillation is lesser or greater and results in a velocity of twice that of the crank pin center with respect to the crank's axis of rotation in the same said direction. Also, the cam follower profile need not be transverse to the axis of piston assembly oscillation as long as the cam lobe center and/or profile is such that it will still constrain the cam follower and likewise the piston-piston rod assembly to a velocity of twice the center of the crank pin in the direction parallel to piston assembly oscillation.
The possible cam follower profiles and cam profiles could be various utilizing straight lines, circles, arcs, involutes, or even polynomial curves provided they constrain the piston assembly to a velocity that is twice the velocity of the center of .
~L~Z~L4~
the crank pin in the direction parallel to the axis of piston assembly oscillation through a predetermined distance of mid stroke. Any control mechanism (gear, cam slider, cam follower inclusive) that through a predetermined distance of mid stroke imparts or restrains motion from the crank to the piston assembly that is sinusoidal and where the piston assembly achieves its maximum velocity at mid stroke and where that maximum velocity is substantially twice the orbital velocity of the center of the crank pin about the axis of crank rotation may be used.
Although one specific cam-cam follower profile has been described for the embodiment of FIGS. 18 and 19, a large number of cam-cam follower profiles can be used.
Such profiles range from a group of cam slider mocha-nisms with primarily a sliding contact between the cam and the cam followers to a group where the action between the cam and cam follower is a rolling contact.
The action between the cam and cam followers may be involute in nature and yet satisfy the equation 2Vcpsin.T.
Rack and pinion gearing is also included for the purposes of this application, and true rack and pinion gearing may satisfy the equation 2Vcp jut would not be inclusive of the sine T function unless modified for Lo the sine function. All of these mechanisms are within the meaning of cam and cam follower as used in this description. However, gearing would sufficiently satisfy the equation 2vcpsin-T for a small portion of mid stroke since Senate =1 when T = 90 degrees but for an inter-face of up to 30 degrees before and after exact mid-stroke the preferred embodiment is a cam-cam follower imparting motion satisfying 2vcpSin.T including the subset of cams that are involutes or gear portions the conjugate surfaces of which are modified to satisfy the relation 2vcpsin.T~ where again Vcp is the velocity of the center of the crank pin and 2vcpSin.T is twice the component velocity of the crank pin on the axis of oscillation of the piston-piston rod assembly.
In the embodiment of FITS. 18 and 19 the engine includes main bearing housings AYE, AYE, lob and 122B
FIG. 19) and crank lips AYE, AYE, 123B and 124B
that maintain the crank centered between main bearing housings AYE, AYE, 121B and 122R. The housings per-mix the connectors 28I and 28J and cranks 301 and 30J to be assembled into the piston-piston rod assemblies EYE
and 70F by passing them through the openings in crankcases EYE and 16F into which the main bearing housings are assembled thereafter. housings AYE and AYE extend into crankcase EYE and serve to reduce the ,.:
ISLE
flexural stress on crank 30I and crank pin 60I thus permitting smaller crank end crank pin dimensions Housings 121B and 122B do likewise. Piston pins AYE, 120B, 120C and 120D serve as fasteners to connect the pistons with their respective piston-piston rods.
To insure proper lubrication to the embodiment of FIGS. 18 and 19 a forced oil system provides oil under pressure from crankcases EYE and 16F through main bearing housings AYE, AYE, 121B and 122B through cranks 30I and 30J into the crank pins 60I and 60J and to their outer surfaces in the manner that the conventional engine lubricates rod and journal bearings. The forced oil lubricates the surfaces in contact where crank pin 60C rotates in mating hole 84C in connector 28C in FIGS.
7 and 8. The lubrication between the connector and the piston rod housing is as described in the embodiment of FIG. 17.
Piston-piston rod assemblies EYE and 70F in the embodiment of FIGS. 18 and 19 experience side thrust forces Lubrication inlets 106C1 106D, 108C and 108D
provide forced oil lubrication at those surfaces as described in connection with FIG. 9.
Although a two-cylinder diesel engine has been described, obviously other types of engines may incorporate the invention and diesel engines with more cylinders may include the invention. External combustion engines as well as internal combustion engines, air compressors and pumps may also incorporate the invention. Ox course, different cranks with a larger number of crank pins, webs and throws may be necessary.
As can be understood from the above description, the balanced engines of this invention have several advantages, such as: (1) they are economical in con-struction because of their simplicity, particularly when used as a two-cycle cylinder diesel engine since they operate smoothly without a large number of cylinders and expensive fuel injectors; (2) they provide operation with less vibration than unbalanced engines; I they provide operation with less crank stress and friction;
(43 they provide efficiency by reducing the amount of energy used to generate harmonic vibrations rather than useful work; and (5) FITS. 7-16 and FIGS. lB-l9 are more compact than conventional engines.
Although a specific embodiment has been described, many modifications and variations of the embodiments are possible within the light of the above teachings without deviating from the invention. Therefore, it is to be understood that, within the scope of the appending claims, the invention may be practiced other than as I
specifically described.
Claims (13)
1. Apparatus comprising a piston rod adapted to be reciprocated within an engine with a predetermined stroke length; a crank; a crankpin having a center, with the center of the crankpin having a predetermined radius of crank rotation about an axis of crank rota-tion; an attaching means connecting at least one piston to said piston rod, whereby said rod is driven by said piston in the direction of motion of said piston; a connector means adapted to be attached at a pre-determined location on said connector means to the crankpin; said connector means being rotatably mounted to said piston rod and having a predetermined center of connector rotation with the distance from the center of rotation of said connector means to the crankpin center being equal to said predetermined radius of crank rotation: the piston stroke length being equal to substantially four times the crank radius whereby the connector means rotates with the same angular velocity but in the opposite direction as the crank; and an interface means between said crank and said piston rod engaging at least a length of surfaces substantially at midstroke to force continuity of piston rod movement;
with the velocity of the piston rod being twice that of the component of velocity of the crankpin center in the direction of oscillation of the piston rod through a predetermined portion of midstroke.
with the velocity of the piston rod being twice that of the component of velocity of the crankpin center in the direction of oscillation of the piston rod through a predetermined portion of midstroke.
2. Apparatus according to claim 1 in which said interface means is a cam slider.
3. Apparatus according to either of claims 1 or 2 in which said interface means is a cam-cam follower.
4. Apparatus according to any of claims 1 or 2 in which there is at least first and second combustion chambers; at least first and second reciprocating pistons adapted to reciprocate in corresponding combustion chambers; at least two crankshafts;
connecting means attached to said reciprocating pistons for driving said two crankshafts as said first and second pistons reciprocate; means connected to said crankshafts for obtaining mechanical power therefrom;
said means connected to said first and second reciprocating pistons comprising a piston rod having first and second ends; said piston rod having mounted to it said first piston on said first of its ends and said second piston on said second of its ends for reciprocating motion therewith; said crankshafts each having a different main bearing about which they rotate; each of said crankshafts having different web portions and different crankpins, whereby they are eccentrically mounted to provide a flywheel effect and rotate in opposite directions to each other; and lubrication means for applying a lubricant to said piston rod at a location removed from said combustion chambers.
connecting means attached to said reciprocating pistons for driving said two crankshafts as said first and second pistons reciprocate; means connected to said crankshafts for obtaining mechanical power therefrom;
said means connected to said first and second reciprocating pistons comprising a piston rod having first and second ends; said piston rod having mounted to it said first piston on said first of its ends and said second piston on said second of its ends for reciprocating motion therewith; said crankshafts each having a different main bearing about which they rotate; each of said crankshafts having different web portions and different crankpins, whereby they are eccentrically mounted to provide a flywheel effect and rotate in opposite directions to each other; and lubrication means for applying a lubricant to said piston rod at a location removed from said combustion chambers.
5. Apparatus according to claim 2 in which the distance from the center of rotation of said connector means with respect to said piston rod and the pre-determined location of connection to said crankpin is equal to said predetermined radius of crank rotation;
first and second pistons are attached to said piston rod by said means for attaching a piston to said piston rod; said piston rod includes substantially flat parallel sides; said means for connecting said connector means to said piston rod, includes internal.
walls defining a cylindrical aperture extending between said parallel flat sides; two edges of said parallel flat sides are rigidly fastened to one piston; the opposite two edges of said flat parallel sides are rigidly fastened to a second piston, whereby said first and second piston drives said piston rod in opposite directions; said means for connecting at least one crankpin includes internal walls defining first and second cylindrical apertures; each of said cylindrical apertures are adapted to mount a different connector means; said first and second apertures are aligned with each other in a direction at an angle to the direction of motion of said piston rod; a second piston rod;
second means for moving said second piston rod in a reciprocating motion; said second piston rod is aligned with said first piston rod; means for connecting a piston to edges of said second piston rod; said means of connecting a piston to said second piston rod is between said second piston rod and said first-men-tioned piston rod; a crankcase; said first and second piston rods each are connected at one end to said piston at its other end to a different crankpin on a different one of said crankshafts; said piston rods and crankshafts are mounted within said crankcase;
first and second cylinders mounted outside said crankcase aligned with said piston rods; said cylinders each are on a different end of said piston rod; and said first piston fits within said first cylinder and said second piston fits within said second cylinder.
first and second pistons are attached to said piston rod by said means for attaching a piston to said piston rod; said piston rod includes substantially flat parallel sides; said means for connecting said connector means to said piston rod, includes internal.
walls defining a cylindrical aperture extending between said parallel flat sides; two edges of said parallel flat sides are rigidly fastened to one piston; the opposite two edges of said flat parallel sides are rigidly fastened to a second piston, whereby said first and second piston drives said piston rod in opposite directions; said means for connecting at least one crankpin includes internal walls defining first and second cylindrical apertures; each of said cylindrical apertures are adapted to mount a different connector means; said first and second apertures are aligned with each other in a direction at an angle to the direction of motion of said piston rod; a second piston rod;
second means for moving said second piston rod in a reciprocating motion; said second piston rod is aligned with said first piston rod; means for connecting a piston to edges of said second piston rod; said means of connecting a piston to said second piston rod is between said second piston rod and said first-men-tioned piston rod; a crankcase; said first and second piston rods each are connected at one end to said piston at its other end to a different crankpin on a different one of said crankshafts; said piston rods and crankshafts are mounted within said crankcase;
first and second cylinders mounted outside said crankcase aligned with said piston rods; said cylinders each are on a different end of said piston rod; and said first piston fits within said first cylinder and said second piston fits within said second cylinder.
6. Apparatus according to claim 5 in which said first and second crankshafts are mounted parallel to each other with the same plane passing through their axes and parallel to said piston rod in a plane perpendicular to the plane of said piston rod.
7. Apparatus according to claim 6 further comprising a first gear mounted to said first crankshaft for rotation therewith; a second gear mounted to said second crankshaft for rotation therewith; and a shaft mounted for rotation to one of said first and second gears for providing power from said engine.
8. Apparatus in accordance with claim 7 comprising a two-cylinder diesel engine.
9. Apparatus according to claim 8 comprising diesel fuel injecting means for injecting diesel fuel into one of said cylinders at the end of each compres-sion stroke; vent means for venting exhaust fumes during the power stroke of said pistons; a plenum chamber; vent means connected between each of said cylinders and said plenum chamber for causing air to be moved under pressure into said plenum chamber by said piston during said power stroke; and second vent means communicating between said plenum chamber and said cylinder causing air under pressure to escape from said plenum chamber into said cylinder when said piston is substantially at the end of its power stroke.
10. Apparatus according to claim 1 in which said interface means includes rack and pinion gearing in which the pinion drives the rack to a velocity twice that of the crankpin center in the direction of piston rod oscillation.
11. Apparatus according to claim 1 in which said interface includes gearing in which the crank gear drives the piston rod gear to a velocity twice that of the crankpin center in the direction of piston rod oscillation.
12. Apparatus according to claim 1 in which the interface includes control means for imparting motion through a predetermined distance of midstroke from the crank to the piston assembly wherein the piston assembly achieves its maximum velocity at midstroke and the maximum velocity is substantially twice the orbital velocity of the center of the crankpin about the axis of crank rotation.
13. Apparatus according to claim 1 in which the crank includes means for imparting motion on the piston assembly that is sinusoidal as is the orbit of the crankpin center.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000461491A CA1226147A (en) | 1984-08-21 | 1984-08-21 | Engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000461491A CA1226147A (en) | 1984-08-21 | 1984-08-21 | Engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1226147A true CA1226147A (en) | 1987-09-01 |
Family
ID=4128563
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000461491A Expired CA1226147A (en) | 1984-08-21 | 1984-08-21 | Engine |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1226147A (en) |
-
1984
- 1984-08-21 CA CA000461491A patent/CA1226147A/en not_active Expired
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