Mechanism for movement transmission in piston engines

This invention relates to a transmission mechanism that allows the transformation of linear movement into circular movement and vice-versa and may be applied to any machine where such a transformation is required. This mechanism includes connecting rods mounted on eccentric wheels, which are in turn connected to the elbow of the crankshaft. Due to this special disposition, these rods do not move in the traditional oscillating manner but only in linear form. Each connecting rod and its piston are cast as a single, light metal piece, without the use of connecting pins. The piston length need not be greater than strictly necessary for holding the ring. The connecting rod length is also reduced. The distance from the crankshaft axis to the cylinder-head union is not bigger than half that now typically in use. The crankshaft length is less than half the length of traditional ones. All this allows, in its use in an internal combustion engine, better thermal and mechanical efficiency, optimization of the relative weight/power and extends the engine's lifetime.

BACKGROUND AND SUMMARY OF THE INVENTION 
The present invention relates to a new transmission mechanism that allows 
the transformation of linear movement into circular movement and 
vice-versa, and may be applied to any machine in which such a 
transformation is required. 
In piston engines, linear to rotational movement transformation is obtained 
by a connecting rod-crankshaft mechanism working in cooperation with 
pistons. As an example, and in order to provide a better technical 
understanding of the invention and its uses and benefits, the description 
below refers to use of the invention in an internal combustion engine. It 
may be useful to keep the following in mind with respect to the basic 
elements that are part of a traditional internal combustion engine, such 
as pistons, connecting rods and a crankshaft: 
1. When explosion occurs, it acts on the piston head, generating a force 
directed to the connecting-rod and another lateral force that presses the 
piston against the cylinder wall, which creates energy losses due to 
friction and tends to wear the cylinder into an oval shape. This 
frictional force reaches its maximum value immediately after the 
explosion, thus causing the sliding of these surfaces to occur under 
extreme lubricating conditions and at very high temperature, pressure and 
speed. 
2. When the piston reaches both maximum points in its stroke, there is an 
abrupt inversion of movement. This acts negatively on the performance of 
the engine in direct proportion to the speed and mass of the group formed 
by the piston, piston rings, pin and one third of the connecting rod. 
3. For a given cylinder volume and rpm, the torque, piston speed, and 
thermal performance may change as a function of the relationship between 
the length of the connecting rod, the piston diameter and the crankweb. 
Based on past experience, a "square piston" or "super square" 
configuration has been generalized as the preferred alternative. It is 
generally accepted that the efficiency depending on these three elements 
(connecting rod, piston and crankshaft) has reached a maximum that cannot 
be surpassed. Moreover, it is well known that these three elements have 
not undergone important changes for many years. All the advances in the 
performance of engines have been due to innovations in other parts of the 
engines (intake, valves, carburation, ignition, camshaft, distribution, 
etc.) 
The three preceding paragraphs describe negative conditions which comprise 
the efficiency of an engine, and which are, among others, very well known 
by those skilled in the art. Several solutions have been proposed 
attempting to solve the problems that have been found. Among them, the 
Wankel rotating engine, with its over forty years of experimentation, has 
had limited success, but it cannot compete with the conventional engine. 
The present invention utilizes the crankshaft-connecting rod-piston 
assembly, which are the elements that have undergone the fewest 
improvements, if any, in the past years. This obviously bestows on the 
present invention a particular importance because, far from attempting to 
alter all the technical evolution of other engine parts, it cooperates 
with them and even makes it possible to enhance their respective 
efficiencies. 
The mechanism of the present invention comprises an assembly formed by a 
crankshaft having a rotatable member mounted on the crankshaft elbow. The 
member is shaped as two partially juxtaposed grooved wheels, one behind 
the other, in such a way that their geometric axes do not coincide. These 
axes are separated and, between both and equally distant from each other, 
is the turning axis that corresponds to the elbow axis. The three axes 
(the elbow axis and each of the wheel axes) are parallel and are on the 
same front-back plane. When the member rotates on the elbow, each of the 
wheels behaves as an eccentric, thus providing a front eccentric wheel and 
a rear eccentric wheel. 
On the front eccentric wheel there are two bearing-mounted connecting rods 
with their distal ends forming the shape of a piston with no joint in 
between, each connecting rod being an integral piece with its own piston. 
The connecting rods are split-head connecting rods with the unique feature 
that each one has only one half of its head and is connected to the 
half-head of the other connecting rod by means of groove pins similar to 
conventional ones. In this way a pair of connecting rods opposed to each 
other is obtained whose longitudinal axes are common and coincident with 
the axis of the corresponding opposite cylinder. 
On the front face of the head of this double connecting rod, an internally 
cogged gear or crown is attached and properly positioned. The center and 
the front-back axis of the crown coincide with the corresponding center 
and axis of the connecting rod bearing. The crown is divided into two 
halves, each one of which remains mounted on a corresponding connecting 
rod if they are separated. The crown tangentially engages the crankshaft 
elbow and this elbow has a gear found on or connected to the contacting 
segment so that as the crankshaft rotates, the gear on the elbow behaves 
as a satellite to the crown. The number of cogs on the crown is double 
that of the satellite gear. 
Forming part of the connecting rod head and on opposite poles there are two 
planes parallel to the axis of the pistons. These planes slide between two 
roller holder plates, which are opposed to each other and attached to the 
fixed structure of the engine so as to form a channel. Inside of this 
channel the head of the connecting rod slides as the crankshaft turns. A 
similar assembly is mounted on the rear eccentric wheel, except that it 
does not have a crown or gear. 
Therefore, one embodiment of the present invention includes an engine with 
two pairs of opposite cylinders and a special feature, which is completely 
new, allowing the movement of the connecting rods to be purely linear 
rather than oscillating. Another new feature is that the pair of cylinders 
is perpendicular one to the other in such a way that when the front 
connecting rods move horizontally, the rear ones move vertically. This 
mechanism also makes the force acting on the crankshaft elbow double in 
intensity compared to the expansion force. 
If necessary, many assemblies can be mounted one after the other along the 
crankshaft in order to meet the special conditions and requirements needed 
for each engine. The best functional balance is obtained when four pairs 
of cylinders or more are used. 
In conventional internal combustion engines, the inertia of the piston (the 
speed of which may, according to the run and rpm of the engine, reach or 
surpass 15 m/sec), and the many high speed movement inversions of the 
piston, rings, pin and connecting rod assembly, negatively effect engine 
operation. These effects increase mechanical losses, produce strong 
vibrations and intensify the friction effect of the piston against the 
cylinder, increasing the wear of both elements. The mechanism of the 
present invention minimizes these effects, mainly because there are no 
lateral forces of the pistons against the cylinder walls. The pistons 
slide inside the cylinders without theoretically making contact with them; 
only the rings do in their sealing function. The piston and cylinder oil 
gap is kept constant along the entire perimeter and at all times. This 
enhances the engine thermal efficiency since the engine can work at higher 
temperatures without the risk of the piston getting stuck inside the 
cylinder, as the absence of friction lowers this risk dramatically. 
Due to the lack of oscillating movement of the connecting rod and the lack 
of lateral force of the pistons, these components do not have a tendency 
to pitch. This allows the piston length to be not greater than the 
strictly necessary one for holding the rings. The reduction in the piston 
length, the short length of the connecting rods, the light weight alloy 
they may be made of and the absence of a connecting pin help to increase 
the mechanical efficiency because of a reduction of mass. It is important 
to emphasize that each connecting rod and its piston forms a single piece. 
Because of the above-mentioned reductions in size, the cylinders are 
short. The distance from the crankshaft longitudinal axis to the 
cylinder-head union is not bigger than half the distance of traditional 
ones. The crankshaft length is also reduced and is less than half the 
length of traditional ones, so that its resistance to torsion shows a 
comparatively remarkable increase. With the proposed mechanism, the need 
for cooling decreases and consequently the cooling system is smaller. 
In light of the foregoing description, it may be easily verified that an 
engine with smaller size and weight may be obtained when using the present 
invention. This, and the functional advantages mentioned above, confirm 
that the weight/power relation of the present invention is highly 
advantageous when applied to internal combustion engines, and compared to 
conventional ones. It is an object of the invention to provide an improved 
mechanism for movement transmission in piston engines, mainly in the 
transformation of linear to rotary movement therein. 
For a better understanding of the present invention, a preferred embodiment 
of the invention will be described (as an illustrative example only and 
not as a limitation on the invention's scope), making reference to the 
attached drawings which show the essential parts of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 4 shows the crankshaft 1 mounted conventionally in an oil pan, and on 
its elbow 2 the cogs of the gear 3 can be seen, acting as satellite for 
the crown or internal gear 4. A member in the shape of two eccentric 
wheels 6 and 7 is rotatably mounted on elbow 2 with anti-friction bearing 
5 in between. Wheel 6 is the front wheel and wheel 7 is the rear wheel. 
The front eccentric wheel 6 supports two connecting rods 8 and 9, which 
allow rotational movement and whose heads are split and united to each 
other with threaded bolts 10. Connecting rods 8 and 9 are mounted on a 
common split anti-friction bearing 11 in such a way that the longitudinal 
axes of the connecting rods are coincident and each connecting rod acts as 
a cover of the head to the other one. The other end of each connecting rod 
increases in volume adopting the shape of a piston 12 and 13. This means 
that each connecting rod and its piston are cast as a single, light metal 
piece (the same alloy used for pistons) and are later machine worked. 
Obviously, no pin or any other type of joint is used. 
FIG. 1 shows that on the connecting rod head, on both opposite poles of the 
axis perpendicular to the longitudinal axis of the connecting rod, there 
is a plateau. Each of these plateaus is covered with a steel skid 14 and 
forms parallel planes to the longitudinal axis. These planes slide with 
the crankshaft movement on roller-holder plates 15. Each plate is 
positioned on the cylinder base through a positional pin 16 (FIG. 5) and 
is attached with two screws not shown on the drawings. The screws 
corresponding to the rear eccentric wheel are shown as reference 28 (FIG. 
6). 
Attached to the front face of the connecting rod head is the internal gear 
or crown 4, which is split in two equal halves. The gear division line 
coincides with the division line of the connecting rod head. This gear is 
fixed and kept in position by pins 10 that run through a lug 17, which is 
a front-back extension of the gear. The gear is also fixed by two threaded 
pins 18 and two splines 19. This allows the disassembling of the 
connecting rod head simply by removing the nuts of pins 10 such that each 
half of the gear will remain attached to each corresponding half of the 
connecting rod head when taken apart. In this way, the location of the 
gear will be kept unchanged, guaranteeing that during reassembling of the 
connecting rod head, the gear may be accurately put back together. This 
gear does not take part, or does so minimally, in the transmission of the 
expansive force to the crankshaft. The eccentric wheels supply this 
function and the gear only participates as an aid to movement. 
FIGS. 1 and 4 show that the rear eccentric wheel 7 has a similar assembly 
attached to it, including connecting rods and pistons 20-21 and 22-23, 
split anti friction bearing 24, skids 25, roller holder plates 26, 
positional spline 27 and attaching bolts 28 (FIGS. 5 and 6). It differs 
from the above-mentioned assembly in that it does not include gear 4 and 
obviously has neither pins 18 nor splines 19. No mention has been made of 
the two pairs of the opposite cylinders 29 and 30 which are not part of 
the invention but must be adapted in their shapes and sizes together with 
the oil pan. 
The kinematic fundamentals of the present invention are as illustrated in 
FIGS. 7 and 8. These figures show a schematic of the mechanism, (starting 
in the same position as shown in FIG. 1), where only the crankshaft, its 
rotation axis 1 and its elbow 2 are shown, together with the front 
eccentric wheel 6, the rear eccentric wheel 7 and the channels on which 
they move. The path followed by the front eccentric wheel is drawn with 
horizontal dashed lines; the path followed by the rear eccentric wheel is 
drawn with vertical dashed lines. The lines represent the channels. A 
complete turn of the crankshaft is schematically shown at 45.degree. 
intervals and the sequence follows the corresponding ordinal numbers. As 
the crankshaft turns clockwise, the eccentric wheels turn 
counterclockwise, as shown by arrows on FIG. 7(A). 
On FIG. 7(C), the expansion force F that is transmitted by the connecting 
rod to the front eccentric wheel 6 is shown. This generates a momentum, 
with lever fulcrum on the spot symbolized by and the resulting force R 
with an intensity modulus twice F. The relation R/F=2 is held constant 
during the whole cycle.