Note: Descriptions are shown in the official language in which they were submitted.
47
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
I 7
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
I 7
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
14
. .
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.
18
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
22
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
I 7
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.
26
~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
27
~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
28
~.~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
32
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.
33
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
34
.
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.
36
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
LO 7
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
38
~;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
42
I 7
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
44
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
46
LO 7
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
47
I
specifically described.
48
