Thermal barrel motor

A motor and especially a thermal motor has a connecting rod assembly comprising two radial rolling surfaces constituted by pairs of cones, one cone of each pair being fixed while the other is carried by a rotatable inclined seat. With this arrangement the position of the pistons of the motor at the end of their strokes is rigidly controlled and centered.

1. Field of the Invention 
This invention relates to motors. 
2. Background of the Invention 
In French Pat. No. 2,194,226, the Applicant describes an axial or barrel 
motor wherein the cylinders have parallel axes equidistantly spaced from 
one another and from a central axis. The motor is a thermal barrel motor. 
The Patent discloses also that the cylinder axes subtend an equal but 
small angle with the central axis and converge at a point on this axis. 
In this motor, the rectilinear reciprocation of the pistons is converted to 
a continuous circular rotation movement around the axis--or to angular 
reciprocatory motion. 
BRIEF SUMMARY OF THE INVENTION 
The essential principle of the present invention is to use a seat with an 
inclined axis. One end of the inclined end of axis rotates with the crank 
of a motor shaft and the other end rotates on a fixed axis by the rolling, 
without slipping, of a cone with two nappes integral with the seat on a 
cone with two nappes on the fixed axis. The rolling without slipping is 
assured by the engagement of teeth mounted on said first-mentioned cones 
and guidance being assured by the contact between pairs of smooth-surfaced 
cones, whereof the conical angle is smaller, equal to or greater than that 
said first-mentioned cones, all bearings or friction-inducing pivots being 
omitted. 
Another feature resides in the possibility of the translational axial 
displacement of the fixed cones and consequently also the movable cones to 
the same degree so as to permit the change of the extreme positions of the 
beginning and end of the piston stroke and thus vary, at will, the 
compression ratio of the motor while stopped or running, by hand or 
automatically, as a function of a selected parameter. 
The basic principle is such as to increase the output of the motor compared 
with known barrel motors and other known motors due to the substitution of 
the rolling with slipping to which they are subject. 
The possibility of axial displacement provides increased output of motors 
according to the invention due to the improved adaptation of the 
compression ratio. 
In French Patent of Addition No. 2,232,951 of the Applicant there is 
disclosed the attachment of connecting rods on a seat serving as a central 
pivot with an arrangement of pistons. 
The first object of the present invention is to modify the range of angles 
of the aforesaid smooth cones and to introduce supplementary cones to 
provide radial rolling surfaces. The aim is to avoid the least 
displacement along the generatices of the cones and thus maintain the 
exact central positioning and absolute control of the end position of the 
piston stroke. 
The provision of these radial surfaces has led to the inversion of the 
position of engagement of the smooth cones and the toothed cones compared 
with that in French Pat. No. 2,194,226, which inversion is foreshadowed in 
said Patent. 
In the description, two arrangements of radial rolling surfaces are 
disclosed by way of example only. 
A second object of this invention is to provide a novel method of securing 
the crank pins which combines the principle of the paired cones disclosed 
in French Pat. No. 2,232,951 with a known guidance method. 
In this aforementioned Patent, the Applicant applies to the connections of 
connecting rods on the seat the same principle as is used at the central 
axis by employing only smooth cone pairs. Indeed, the analogy with the 
central axis is not total since the length of the connecting rods is not 
infinite, the connecting rods subtending an angle with the axes of the 
cylinders so that the mounting of the paired toothed cones would be 
incorrect. Moreover, they would be cumbersome and besides would not have a 
transmitting force as have the toothed cones at the central axis. 
To avoid any slipping of the contiguous cones along their generatices of 
contact the means employed at the central axis (radially abutting cones) 
is not convenient due to the absence of toothed cone pairs. 
In each of the two pairs of smooth cones, one has a summit angle of 
180.degree. which eliminates any relative axial movement. The radial 
guidance is assured by a hemi-spherical bearing which provides a slight 
slippage and thus a slight friction; this concession to known arrangements 
only involves slight friction since the radial forces only represent 6% of 
the axial forces applied to the cones when rolling. 
A third object is to provide a good connection between the pistons and the 
connecting rods. 
A preferred arrangement is a simple bi-conical piston connecting rod having 
a spherical fluid-tight segment in one or two parts lodged in the same 
throat and a known thin double-annular scraper ring. 
Two more complicated modifications are proposed. The first uses a 
conventional U-shaped scraper ring mounted on a floating skirt, while the 
second uses a piston with a cylindrical exterior surface provided with 
conventional fluid seals, this piston no longer being rigid with the 
connecting rod but articulated thereto in the same way as it is to the 
seat, with a very small clearance angle. 
A fourth object of the invention is to locate at the exterior of the motor, 
at a location which is easily accessible, a spring determining 
automatically the compression ratio as a function of the load, one element 
at least of this spring being a leaf spring serving simultaneously to 
angularly adjust elements fixed against rotation at the axis and to 
transmit to the motor casing a reaction couple. These two functions, 
difficult enough to achieve simultaneously by two different mechanisms, 
are facilitated by the use of the leaf spring. 
A fifth object of the invention is to provide a modified pivot mounting for 
the motor shaft. The axial displacement by several millimetres of the 
motor shaft and flywheel, to follow variations in the compression ratio, 
is not a serious inconvenience since an adjustable control for a clutch 
carried by the flywheel can be provided, there being axial displacement of 
the gearbox shaft. 
However, most automobile manufacturers would prefer to have the usual 
axially fixed flywheel without introducing a supplementary constraint. 
This is why it is preferable to provide a construction with a 
longitudinally fixed shaft. Naturally the shaft can be made in two 
relatively sliding parts, one part being carried by the crank and being 
axially displaceable, while the other carries the axially fixed flywheel, 
the adjustment being achieved by keyways. The inconveniences of sliding 
keyways insofar as significant alternating force couples is concerned are 
known. Also, the invention proposes the axial sliding of the crankpin in 
the eye of the crank by means of a nut, whereof the exterior surface is a 
cylinder with an axis parallel to the motor axis and which mounts inside a 
swivel. In these conditions, the crank, the shaft and the flywheel are 
longitudinally fixedly retained by an abutment. The swivel follows the 
axial displacement of the central shaft; the sliding cylindrical 
adjustment of the eye of the crank cannot sustain couples but only 
relatively small forces and functions with a very slight play.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The casing of the motor shown in FIG. 1 comprises two principal castings 
bolted concentrically together; one part 1 of the casing enclosing the 
moving parts and carrying the motor shaft 3--3' and the other part 2 
comprising the cylinder head carrying the cylinders, the cooling circuit, 
and the valves, and, in its central portion, the reaction shaft 4. 
The mechanism comprises three main assemblies: the motor shaft 3--3', the 
reaction shaft 4, and the seat 5-6. 
The motor shaft 3--3' comprises, for convenient construction, an exterior 
shaft 3 and an interior shaft 3' concentrically enclosed in one or other 
of the parts of the casing by keys (not shown). The shaft 3 carries a 
flywheel 30 and conventional sealing arrangements together with the valve 
operating mechanism (not shown). 
The shaft 3 carries the crank 10 which receives a rotational movement by 
means of the rollers of a swivel 9 mounted on the tail 8 of the seat 5. 
The center of the rotational movement of the crank is at D and relative 
displacement along the axis y--y' between the seat 5 and the crank 10 is 
prevented by appropriate means such as circlips. 
On the shaft 3 are mounted, in opposition to the crank 10, detachable 
counter-weights 31. 
The shaft 3--3' of the motor is carried by roller bearings 28 and 29 which 
permit a certain axial displacement of this shaft. The cut-away portion 32 
of the flywheel gives rise to an imbalance in order to create, in 
rotation, a turning couple opposed to the imbalance formed at D by the 
crank 10 and the tail of the seat. 
Coaxial with and opposite to the shaft 3--3' is the reaction shaft 4 which 
is centered relative to cylinder head 2 by bearing surfaces 36 and 33. 
Toroidal sealing joints are mounted on the bearing surfaces. For example, 
the joint 34 is mounted on the surface 33. The volume 35 between the shaft 
4 and the casing 2 is filled with oil under pressure from a pump (not 
shown). A nozzle 37, screwed to the shaft 4, ensures the lubrication of 
the mechanism and also, as will be explained later, the damping of axial 
movement of the shaft 4. 
The axial damping action of the shaft slows down the motion of the pistons 
at the end of each compression stroke without inconvenience and without 
slowing down the return stroke (to prevent pinking). 
On the end of the shaft 4 is connected an arrangement of leaf springs, two 
springs 38 and 39 only being shown. The main spring 38 as shown in FIG. 1 
and FIG. 4, is supported at 40 by supports 42 integral with the casing 2. 
Rotation of the springs and in turn the shaft 4, by the abutments 41. 
Beneath the spring 38 and around the end of the shaft 4 are located either 
supplementary coil springs 43 or cylindrical abutting braces 44, either of 
which are supported by the casing 2. Measurement of the shaft 4 in the 
other direction is prevented by the surfaces 45 of the casing 2. 
According to the basic principle, the shaft 4, which is prevented from 
rotation by the exterior spring 38, carries the fixed elements of the cone 
with 2 nappes along the axis x--x'. On a flared annular portion 36' of the 
shaft are located the fixed outer cones with toothed and smooth surfaces. 
The fixed inner cones with toothed and smooth surfaces are located on a 
central projection of the shaft 4. The description of these fixed cones 
will be made hereafter at the same time as the corresponding cones of the 
seat. 
The seat 5-6 comprises the seat proper 5 and a counter-seat 6. These two 
parts are assembled concentrically and attached to the assembly by bolts 
7. The end or tail 8 carries, coaxial therewith, the bearing 9. The 
counter-seat 6 carries in its interior the moving inner smooth and toothed 
cones and exteriorly the moving outer smooth and toothed cones, which 
cones are located concentrically between the seat 6 and the seat 5. 
In the embodiment shown in FIG. 1 the different cones are as follows: 
The smooth outer fixed cone 19 is formed directly on the flared portion 36' 
of the shaft 4 and has a summit angle of 180.degree.-.alpha.. 
The smooth outer moving cone 12 is formed directly on the counter-seat 6 
and has a summit angle of 180.degree.-.alpha.. This cone 12 rolls without 
sliding on the preceding cone 19. 
The toothed outer fixed cone 18 is located on the flared portion 36' of the 
shaft 4 and forms a primary cone with a summit angle of 
180.degree.-.alpha.. This cone engages with the toothed outer moving cone 
11 carried by the counter-seat 6, thereby forming a primary cone of the 
same summit angle. 
The smooth inner fixed cone 25 is formed on an annulus member 23 of 
hardened steel located and centered on the projection 26 of the shaft 4. 
The smooth inner fixed cone summit angle is approximately 60.degree. and 
its generatrix is cut into two almost equal parts by the bisectrix AB. 
The smooth inner moving cone 16 is formed on an annulus 15 of hardened 
steel located and centered on the counter-seat 6. The summit angle of the 
smooth inner moving cone is equal to that inner fixed cone 25 increased by 
2.alpha.. 
The toothed inner fixed cone 21 is located and centered on the projection 
26 of the shaft and forms a primary cone with a summit angle of 
180-.alpha.. The inner fixed cone 21 engages the toothed inner cone 14 
forming an identical primary cone which is carried by the counter-seat 6. 
In these two toothed pairs 11-18 and 14-21, the circumferential play of the 
teeth is minimal lower than or equal to 0.05 mm. 
The rolling surfaces are illustrated in the example of FIG. 1 as follows: 
A radial outer fixed cylindrical surface 20 (a cone with a summit angle of 
zero) is formed on the flared portion 36' and the shaft 4, thus limiting 
exteriorly the cone 19. 
In communication with this surface 20 is an exterior moving surface 13 of 
summit angle 2.alpha. formed on a rim 61, mounted on the counter-seat 6 
and located to the interior of the toothed cone 11. 
The inner radial abutment is made by the fixed cone 25 in conjunction with 
the moving cone 16. The summit angles of these cones is maintained small 
in order to ensure radial abutment by the mating of a fixed planar face 24 
(summit angle 180.degree. ) with the cone 17 of summit angle 
180.degree.-2.alpha.. 
The moving face 24 is formed on a member 22 mounted concentrically on the 
projection 26 of the shaft between the annulus 23 and the toothed cone 21. 
These three members 23, 22 and 21 are locked onto the projection of the 
shaft 26 by a screw 27 and are further prevented from rotating by a 
splined connection with the shaft. 
The cone 17 is formed on the annulus 15, which is cylindrically encased 
with the teeth 14. These two members are attached to the counter-seat 6 by 
means not shown. In the example shown in FIG. 2, the different cones are 
as follows: 
The two toothed pairs are identical with those shown in FIG. 1, 11-18 and 
14-21 and are mounted with the same tolerance set forth above. 
The outer supported cones 12 and 19 are also identical with hose of FIG. 1 
each having a summit angle of 180.degree..alpha. following the primary 
cones generated by the bisector of FIG. 2. 
Outer abutting surfaces 13-20 are also similar with those in FIG. 1. 
On the contrary the smooth inner cones are entirely different. The fixed 
cone 62 of summit angle 180.degree.-.alpha. mates with the moving cone 63 
of the same summit angle and can thus roll, without sliding, following the 
primary cones generated by the bisectrix AB. 
The fixed cone 62 is formed on the annulus 64 attached to the projection 26 
of the shaft. The moving cone 63 is formed on the annulus 65, located 
between the toothed cone 14 and the central axis of the counter-seat 6. 
The two radial rolling abutting surfaces necessitated by the shape of the 
supported cones 62 and 63 are provided by a cylindrical surface 66 formed 
on the counter-seat, which is in rolling contact with a mating conical 
surface 67 having an angle 180.degree.-2.alpha.. The conical surface is 
formed by the flared portion 36' of the shaft 4. The cylindrical surface 
66 is formed slightly barrel-shaped. 
The seat 5 is provided with cylindrical lugs. One of these lugs is visible 
in FIGS. 1,2,5 and 6. Each lug carries a connecting rod attachment 
corresponding to one cylinder. Referring to FIGS. 5 and 6, the center of 
attachment of the connecting rod is at a point 0. This point 0 is located 
in a plane z--z' perpendicular to the axis y--y' at the point S of its 
intersection with x--x'(see FIG. 2). As is known, and which has been 
already described in French Pat. No. 2,232,951, all the points of this 
plane and particularly point O are described when y--y' turns around 
x--x', a trajectory which is the intersection of a sphere of centre S and 
radius OS with a cylinder inwardly tangential to the sphere on an axis 
parallel with x--x' and of the diameter OS (1-cos.alpha.). 
The projection of this trajectory on the crosssection of FIG. 1 is a 
circular arc of center S and radius OS. Its projection on a plane 
perpendicular to the preceding plane is a curve following a lemniscate 
path (a FIG. 8 shaped curve) and its projection on a plane perpendicular 
to x--x' is a small circle of diameter OS (1-cos.alpha.), at right angles 
to the tangential cylinder. 
It has been found noteworthy to make the axis MN of the cylinder under 
consideration (FIG. 5) intersect the axis of the tangential cylinder. As a 
result, the point O is always a constant distance from the axis MN and the 
connecting rod PO always makes a constant angle .beta. with the axis MN. 
At two points of the piston stroke above and beneath the centre, the point 
O is above the axis MN as also is the angle .beta.. It follows that the 
axis of the connecting rods P.O are parallel to two center points moved an 
angle .beta. from the axis MN. If one considers two limiting center 
points, all the connections of the connecting rod on the seat are shifted 
by an angle .beta. in relation to the axis MN and AB. In this case in 
particular the bisectrix of the angle .alpha., KK' is shifted by an angle 
.alpha. in relation to the bisectrix AB. Similarly, at the point O, the 
axis of the support 52 fixed to the lug of the seat 5 is shifted by an 
angle .beta. in relation to y--y'. 
It is found that all intermediate positions of the point O between tthe two 
center points do not suffer this general movement and in all parts of the 
trajectory of O, the angle of PO with the axis of the support 52 remains 
almost constant, with a small error which is almost negligible, and which 
can be stated as follows with: 
##EQU1## 
This being understood, the remainder of the motor can be described as 
follows: 
With reference to FIGS. 5-8, the extension of the connecting rod 55 has an 
axis PO (FIGS. 1 and 5). It is adjustable within the piston 60 by screwing 
or other axially movable means. It has a support surface 58 which is 
planar and perpendicular with its axis OP at a distance O such that the 
bisectrix KK' meets it at a point R a little nearer to the circumference 
than the center. On a flared portion of the extension, is provided another 
plane surface 57 also perpendicular to the axis PO and situated at a 
distance from O in the direction towards P, such that the bisectrix KK' 
meets it at point T which is almost at the middle of the annulus. The 
exterior surface 56 of the flared portion is a spherical segment of centre 
O. The extension is encased in a fixed casing on the lug of the seat 5 
(FIGS. 5 and 6). This casing comprises essentially the members in contact 
with the surfaces of the stamp, that is, the support member 52 of hard 
steel terminated by a cone 53 of summit angle 180.degree.-2.alpha.. This 
cone is very slightly bevelled about a point R, the center of contact with 
the plane 58 of the extension: 
the annular member of a counter-support 47 with a conical surface 54 of 
summit angle 180.degree.-2.alpha.. This surface is slightly bevelled about 
a point T, the center of contact with the annular surface 57 of the 
extension. 
a bearing member 49 of special light-weight metal of low coefficient of 
friction. The bearing has an interior hemispherical surface 51 which is in 
sliding contact with the spherical segment 56 of the extension. 
These three members are adjusted concentrically in a casing 45. A screw 46 
locks this casing 45 against the lug which consequentially connects the 
three abovementioned members against the lug. Between these three members 
are interposed two wedges 48 and 50, the former regulating the play of the 
spherical contact of the lateral guiding and the latter regulating the 
axial play of the rolling contacts. The casing 45 has a maximum thickness 
at the lower generatrix nearest to x--x', since, in this region, the 
inertial forces of the piston are greatest. This thickness progressively 
decreases and the portion opposite to x--x' is completely truncated since 
there are practically no forces in the casing in this region. This 
configuration is important to reduce the inertia of the seat. 
The enlarged view of the piston 60 in FIG. 7 shows its simplicity. The 
piston is formed by a flared portion of the connecting rod from a throat 
to a large radius 68 formed integrally with the end 69 of the piston. This 
formation allows a maximum flow of heat to be diverted towards the center 
of the connecting rod which is well surrounded by oil to relieve the 
piston rings of excess heat. 
The skirt 70 of the piston is provided with a groove 71 for mounting the 
piston scraper rings. The center of the rings define a point P which is 
the center of nutation of the connecting rod. The single or double scraper 
rings 72 have a spherical contact surface with the bore of the cylinder. 
In order to retain perpetual contact with the cylinder in the course of 
its nutation, the width a is of necessity greater than the ample .beta. 
.phi.. On either side of the scraper ring 72 the surface of the skirt is 
conical in a fashion whereby a generatrix of the inner cone 73 supported 
on the cylinder is inscribed in the cylinder in all the positions of its 
travel. This is made possible by the low lateral thrust of the piston. The 
outer cone 74, on the firing side, never touches the bore. The oil scraper 
ring is constructed by two thin segments 75, between which are located 
orifices 76 leading annularly around the skirt 70. 
The first alternate embodiment (FIG. 8) is an improved construction in 
which the piston has a floating skirt as described in French Pat. No. 
2,232,951. Here, the piston 95 is integral with the connecting rod 55 and 
is provided at its rear with a spherical surface 96 which cooperates with 
a counter piston 97. The counter piston is integral with a cup 98 which is 
provided with a spherical central surface 99 mounted on a bearing 100 of 
the piston rod 101. 
As indicated above, the piston 95 is conical to one side of a groove in 
which are located two scraper rings 72. The center P of this groove is the 
center of movement of the nutation of the piston 95 and its connecting rod 
55. 
In the modification of the piston shown in FIG. 9, the piston 77 resembles 
exteriorly a conventional piston as do the scraper rings. It carries at 
its center a plug 78 with the support cone 79 of summit angle 
180.degree.-2.beta.; an annulus 80 with the support cone 81 of the same 
summit angle; the arrangement of radial ribs 82; and a detachable 
transverse plate 83 for immobilising the cone 81. This plate 83 is 
cut-away in order to provide apertures 84 for the passage of oil. The 
extension of the connecting rod 55, above described, is assembled with the 
extension 55 adjacent the piston, by means of a sleeve 86. The extension 
85, similar to the extenstion 55, carries two planar surfaces 
perpendicular to its axis. One surface is an interior surface 87 which 
bears against the cone 79. The other surface is an exterior surface 88 
which bears against the cone 81. Moreover, the flared portion is limited 
by a spherical segment 89 adjusted with play in the hemispherical surfaces 
90 of the radial ribs 82. Two sets of wedges permit adjustment 
respectively in the axial play and the peripheral play. 
The piston rod, constituted by the two extensions, has an axis which always 
makes an angle .beta. with the axis MN of the cylinder and the piston, and 
turns around the axis MN with a speed 2w (w being the speed of the motor). 
The arrangement of the motor with a fixed longitudinal axis is shown in 
FIG. 3. The motor shaft comprises, in a first arrangement, the shafts 3 
and 3' housed one within the other and fastened together by pins. The 
roller bearing 28 adjacent the cranks is maintained identical to bear a 
high load. On the contrary, the bearing 29 in the first modification is 
replaced by a bearing with two oblique ball races which can bear a higher 
thrust imposed through the seat 5 or through the exterior elements by the 
fly-wheel 30. 
The crank 10 is traversed by a bore 91 along its axis u--u' parallel to 
x--x'. The point D, the centre of the swivel, is at the intersection of 
the axes u--u' and y--y'. The distance from the point D to the axis x--x' 
is the same as that in the arrangement shown in FIG. 1. The length SD and 
the angle are likewise the same as in FIG. 1 .alpha.. The seat 5 on the 
axis y--y' carries in the same fashion a swivel bearing 9. The exterior 
annulus of the seat, however, includes a cylindrical machined surface with 
an axis u--u' slidingly adjustable in the bore 91. This bearing, as is the 
seat, is shown in FIG. 3 in its highest driven position. On the thrust of 
the shaft 4, the bearing can vary the position of the shaft 3--3' by a few 
millimetres, the straight line SD being displaced parallel to itself. 
It is not necessary that, during operation, the annulus 92 turn in its bore 
91 which moves the axis xy' out of the plane y--y'/x--x'. It has no 
natural tendency, the angle .alpha. being sufficiently large, to oppose 
with jamming this relative rotation. However, for insuring rigidity, a 
cylindrical stud 94 fixed in the shaft 3' near its axis is slidably 
adjustable in the corresponding groove 93 of the annulus 92 and positively 
prevents any tendency for unwanted rotation. 
The operation of this barrel motor is as follows and is described 
particularly with regard to the link mechanism. 
The pistons reciprocate by operation of the connecting rods. They are the 
source of the inertial forces during the rapid operation of the motor. 
The resultant force F of the compression strokes of the pistons is directed 
along the axis PO. The connecting rod supports an equal reaction R at a 
movment arm F X OR. This torque is balanced by an opposite torque giving 
two reactions. A lateral reaction on the piston 60 and 73 and a lateral 
reaction on the guiding hemispherical surface 56. These reactions have a 
value: 
##EQU2## 
which is approximately 0.06 F. 
It can be seen that the lateral forces on the piston and the bearings are 
relatively small. 
The reaction due to the inertial forces F' have for their value 
##EQU3## 
which is approximately 0.16F'. F' is small because the mass of the piston 
connecting rod is small. 
These reactions (which result from the compression forces and the inertial 
forces) oppose one another. Their resultant is thus smaller than either of 
them. 
However, this supplementary reaction should not be forgotten, which is that 
caused by the connection of the connecting rod (FIG. 5). The connecting 
rod turning through an angle .beta. around the axis MN at an annular speed 
2w (if w is the speed of the motor shaft) is subjected to a centrifugal 
force 4.M.W.sup.2.OP. This force combines with the two aforesaid reactions 
(compression and inertia) and acts in the bearing 49. The calculations 
made in all operational states of the motor show that the resultant force 
of all the radial forces on the bearing 40 remains very small.