Note: Descriptions are shown in the official language in which they were submitted.
10796~7
This invention relates to a piston power machine and piston working
machine having a jacket enclosing at least one cylindrical generating chamber,
at least one piston in the generating chamber which can be moved back-and-
forth in the direction of its longitudinal axis as well as rotated about its
longitudinal axis. A driving joint mechanism is connected with the piston
and in response to the back-and-forth movement of the piston, applies a rotary
motion to the piston about its longitudinal axis and converts the piston
motion into rotary motion of a driving shaft or, conversely, the rotary
motion of a driving shaft into the piston motion.
It is an object of the present invention to provide a piston machine
in such a manner that, without difficulties and particularly without
additional expenditure for the driving joint, several cylinders can be
arranged adjacent each other with their pistons connected to a common
shaft. The invention achieves this object by having the driving joint
designed as a crankshaft, the shaft journals of which are arranged diagonally
to the direction of the stroke of the piston and form the driven end of the
- shaft or the driving shaft. The crankpin of the crankshaft is connected with
f~ the piston by a joint which is movable in a longitudinal direction along the
crankpin.
`~ 20 The inventiva scope is to be seen in that for a piston, capable of
~`'! carrying out a lifting and simultaneously a rotational movement, no compli-
cated gear is required, but merely a crankshaft, requiring however that
between the crankpin, the crankshaft and the piston shaft a joint is
provided which permits rotation about the longitudinal axis of the crank
, pin as well as about an axis extending at an angle thereto. A crankshaft
offers the advantage that it represents a simple structural component,
permitting in a particularly simple fashion to assemble any desired number
of pistons to form a machine with several cylinders.
The expenditure for and the space requirement of the driving joint
is low and if, instead of only one cylinder, several cylinders are provided
adjacent each other, it is sufficient to extend the crankshaft accordingly
- 1 - ~
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107964~7
whereby the cylinders can be placed in staggered relation to each other in
the circumferential direction of the crankshaft. An additional advantage
of such a driving joint, independently of the number of the cylinders,
consists of the fact that no pinions or the like are required in order to
transmit the movement of the piston to the driven end of the shaft or the
rotation of the driv mg shaft to the piston or pistons.
Instead of extending th.e crankshaft, or in addition to it, also a
second driving joint, which can be ved in longitudinal direction, c~n b~
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1079647 ~
arranged on the crankpin through which at least an additional piston is
connected to the driven end of the shaft or to the driving shaft.
In this way, it is not only possible to provide an opposed cylinder
arrangement, but also an extremely compact radial construction with four
Ristons or two double pistons can be achieved. It is, furthermore, an advan-
tage that an excellent mass equilibrium can be achieved with a relatively
; low expenditure. In order that the two joints are always placed in phase
opposition, the crankpin consists, in the case of a preferred design, of two
sections which are connected with each other and are placed diametrically with ~ -
regard to the axis defined by the shaft journals, with the sections each
carrying one of the joints. The same effect can be obtained with an undivided ~`crankpin when this crankpin forms an acute angle with the axis defined by the ~- -
shaft journals and this axis cuts through the center between the two crank
webs
Partîcularly ~avorable conditions are obtained when the longitudinal
axis of the crankpin passes through the center of gravity of the piston or a
straight line passing through the center of gravity and parallel to the longi-
tudinal axis of the piston cuts through the longitudinal axis of the crank-
pin.
In the case of a particularly advantageous design, the longitudinal
axis of the crankpin forms an acute angle of, preferably, about 45 with the
longitudinal axis of the piston and the longitudinal axis of the shaft
journals. In this way, a particularly favorable path of the motion of the
center of gravity of the piston is obtained. It is especially expedient, in
this instance, to arrange the crankpin in such a manner that its longitudinal
axis cuts through the longitudinal axis of the piston.
Different designs are possible for the driving joint between the
crankpin and the piston. A ball-and-socket joint can, for example, be pro-
vided, the ball of which is located on the crankpin in such a way that it is
movable in the longitudinal direction of the crankpin. A joint with a sleeve
.. .. . . .. .. .. .
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1079~47
placed on the crankpin, which is connected with the piston and is pivotable
about an axis perpendicular to the longitudinal axis of the crankpin, in-
volves special advantages and this, in particular, when it is a question of
designs with a crankpin being placed at an angle to the shaft journals. If
the crankpin extends at an acute angle to the shaft journals, then the sleeve
can be connected with the piston by means of two jointed pins the longitudinal
axis of which lie in a common plane on which the longitudinal axis of the
piston is perpendicularly disposed. . :
The invention is explained in greater detail herein by means of the -
several embodiments shown in the drawings, wherein:
. Figure 1 is a schematically shown longitudinal cross-section of a ~:
.
first embodiment of the invention;
. Figure 2 is a schematically shown cross-sectional view of the pis-
-~, ton and of the joint of the first embodiment;
-, ,
~. Figure 3 is a schematically shown longitudinal cross-section of a
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second embodiment of the invention;
. Figure 4 is a schematically shown cross-sectional view of the piston
and of the joint of the second embodiment;
~igure 5 is a schematically shown longitudinal cross-section of a
third embodiment of the invention;
Figure 6 is a schematically shown cross-sectional view of the third
-~ embodiment with a position of the crankshaft turned by 90 in comparison with
:- the position according to Figure 5;
Figure 7 is a schematically shown longitudinal cross-section of a
: fourth embodiment of the invention;
Figure 8 is a section.taken along line VIII-VIII of Figure 7;
Figure 9 is a schematically shown longitudinal cross-section of a
fifth embodiment of the invention;
Figure 10 is a section taken along line X-X of Figure 9;
Figure 11 is a schematic longitudinal section of a sixth embodiment;
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:107964~7
and
Figure 12 is a sectional plan view corresponding to Figure 11. ~ -
The first embodiment of the invention shown in Figures 1 and 2 has
a double-acting piston 1, having two similarly arranged piston heads 5 with
circular cross sections. The pistons 5 have a relatively insignificant axial
length and are each provided with a piston ring 6. The two piston heads 5
are connected with each other by means of an eccentrically positioned piston
shaft 4 having a sector-shaped cross section such that the radius of curvature
~! of the cylindrical outer surface of the piston shaft 4 is somewhat smaller
than the radius of curvature of the outer surface of the piston heads 5.
Owing to this design, the center of gravity of piston 1 is disposed in the
piston shaft 4 outside the longitudinal axis of the piston heads 5, i.e.,
eccentric thereto.
' The two piston heads 5 are each received in a respective cylinder in
a manner permitting longitudinal ~nd rotational motions therein. Each cy-
linder consists of a jacket 2 and a cylinder end wall 7. The two identical
:~
c~linders are coaxially arranged and connected with each other in a manner not ;
sho~n in the drawings. However, it is also possible to provide a common
jacket for both c~linders with penetrations in that area of the jacket which
does not limit the two combustion or power generating spaces 8. Valves and
openings associated with the spaces 8 for the supply and discharge of fuel
and air, when designed as an internal combustion machine, or of a working
medium in the case of a working machine or pump design, are not shown, but can
be provided in a known manner.
A crankshaft, the overall construction of which is designated by ~-
reference numeral 10, is provided as a means for the conversion of the movement
of the piston 1 into a rotary motion of the driven end of a driving shaft or
the conversion of the rotary motion of a driving shaft into the motion of the
piston. The longitudinal axis of the two shaft journals 11 cuts through the
longitudinal axis of the piston 1 and of the two cylinders in the plane
107964'7
equidistant between the t~o end walls 7. The crankpin 12 of the crankshaft
lQ, is connected with the shaft ~ournals 11 in the customary manner by means
o two crank webs 13 and is parallel and eccentrically arranged to the longi-
tudinal axis of the shaft journals 11. A ball 14 of a ball-and-socket joint,
connecting the crankshaft 10 with the piston 1, is mounted on the crankpin 12
in such a manner that it is pivotable as well as shiftable in the longitudinal
direction of the crankpin 12. The ball 14 is pivoted in the piston shaft 4,
for which purpose the piston shaft is provided with a penetration 15 which
has two spherical segments arranged symmetrically with respect to the trans-
verse median plane of the piston 1, the segments comprising bearing surfaces
; or the ball 14. As is shown in the drawings, the penetration 15 is conically
enlarged towards both ends so that, as best seen in Figure 2, the crankpin
does not contact the piston shaft 4.
Instead of the ball 14, a cylindrical element could be used, the
longitudinal axis of which is parallel with the longitudinal axis of the
piston and, preferably, passes through the center of gravity of the piston.
Such an element would be provided with a bore hole for the crankpin 12,
~enetrating the element in the radial direction, and would be supported in
the penetration 15 in such a manner that it would be pivotable about its
longitudinal axis. A cross-section of such design according to Figure 2
would result in the same sectional view as shown therein.
As is shown in Figures 1 and 2, the crank webs 13 can either be
entirely or partially arranged in the space between the two piston heads 5.
The distance between the webs 13 results from the necessary shifting range
or the ball 14 on the crankpin 12 and, as is shown in Figure 2, from the
arcuate angle of rotation of the piston shaft 4.
During operation, the piston 1 performs a rotary motion around its
longitudinal axis in addition to the translational motion resulting from the
movement of stroke since, as is shown in Figure 2, the motion of the crankpin
3a ]2 induces a shifting, in a direction diagonally to the direction of the
~ 5 ~
107964~
stroke, of the center of gravity o the piston 1 uhich passes through the
center of the ball 14 and lies thus on the longitudinal axis of the crankpin
s 12. This motion leads to a vement of the center of gravity on a circular
path about the longitudinal axis of the piston owing to the fact that the
ball 14 is mova61e about in a longitudinal direction on the crankpin 12.
Therefore, the path taken by the center of gravity of the piston 1 during
each stroke consists of the longitudinal stroke movement and a to-and-fro
rotary motion in a transverse plane.
-~ The crankshaft 10 can be extended towards one of the two sides so
- 10 that a design with several cylinders, as is customary for piston engines, can
` be achieved without any difficulties.
~lth a suitable selection of the eccentricity of the crankpin 12,
i.e,, when the plston in the position according to Figure 2 has been subjec-
ted to a turn b~ 9Q in comparison with the position according to Figure 1, a
contlnuousl~ constant dlrect1on of rotation of the piston 1 around its longi-
tudinal axls can be provided.
The embodiment of the invention shown in Figures 3 and 4 differs
rom that according to Figures I and 2 essentially by an alternate design of
the crankshaft 110. With the exception of the penetration 115, the piston 101
is designed in the same manner as the piston 1. It goes without saying that
other piston forms can also be utilized in this instance as in the case of
the irst embodiment. By the same token, the two cylinders with their jackets
102 and their end walls 107 are, in principle, designed in the same way as in
the case of the first embodiment.
; The longitudinal axis of the crankpin 112 of the crankshaft 110 forms
an angle of about 45 with the longitudinal axis of the two shaft journals 111
and cuts~ at the same angle~ through the longitudinal axis of the piston 101
in the transverse median plane of the two cylinders. The two crank webs 113
have a different design. One of them is designed as driven plate 118 and, if
3Q required, counterweights can be provided at the crank webs.
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` 10796~7
:
A sleeve 114, which is arranged in the penetration 115 of the piston
shaft 104l is placed on the crankpin 112 in such a manner that it can be
pivoted and shifted in the longitudinal direction of the crankpin for the
connection of the crankpin 112 with the piston shaft 104 of the piston 101.
Two jointed pins 116, engaging into the sleeve 114 in radial directions at
diametrical points, are received in a bore 117 of the piston shaft 104 by
means of bearings, which are not shown. This bore hole is in the transverse
median plane of the piston 101 and passes through its center of gravity.
As is shown in Figure 3, the penetratiGn 115 essentially consists
of two sections conically enlarged towards the outside thereof which permits
movement of the sleeve 114 past the conical surfaces, said movement being
- determined by the longitudinal axis of the crankpin.
As in the case of the embodiment according to Figures 1 and 2, during
operation, the center of gravity of the piston 101 makes a back-and-forth
translational motion and, simultaneously, a back-and-forth rotational motion
around the longitudinal axis of the piston 101.
It would be possible to eliminate one of the two crank webs, for
example, the crank web 113, without changing the course of the motions of the
- piston, i.e., by designing the crankpin 112 as a pin freely projecting from ~-
one of the crank webs.
As in the case of the embodiment according to Figures 1 and 2, no
gears are required for the conversion of the piston motion into the rotary
motion of the shaft journals 111 or for the conversion of the rotary motion
of the latter into motion of the piston 101. Furthermore, the crankshaft 110
can be extended towards one of the two sides so that the customary construc-
tion with several cylinders can be achieved.
The two-cylinder engine shown in Figure 5, represents an internal
combustion engine, but which could also be a pump, and has two cylinders 201
and 202 arranged coaxially opposite each other, i.e., in an opposed arrange-
ment. A crankshaft, the overall construction of which is designated by
107964~
reference numeral 203, is arranged in the plane of symmetr~ between the two
,~ cylinders 2Ql and 202. Two crank webs 204 and 205, both of identical design,
are designed as driven plates and support counterbalance weights 206 which
are staggered by 180, i.e., in phase opposition. The crankpin 207 of the
crankshaft 203 extends from the crank web 204 from a point diametrical to its
.i
counterbalance weight 206 to a point diametrical to the counterbalance weight
206 of the crank web 205, the radial distance of the crankpin 207 at the webs ~
204, 205 from the longitudinal axis of the shaft journals 208 of the crank- `
shaft 203 being the same. The longitudinal axis of the crankpin 207, therefore, -~
cuts through the longitudinal axis of the shaft journals 208 in the center
between the two crank webs 204 and 205 at an angle of about 45. -~
A piston 209 or 210, which can be shifted in the longitudinal
direction of the cylinder and pivoted about the cylinder axis, is arranged in
a respective one of the two cylinders 201 and 202, the longitudinal axes of
which pass through the point of intersection of the crankpin 207 with the
-; longitudinal axis of the shaft journals 208. The design of both pistons is
identical and their cylindrical piston heads have at least one piston ring
211. Adjacent each piston head, 209, 210 there is a piston shaft 212, 213,
respectively, located eccentrically of the piston head and semicircular in
cross-section. The piston shafts 212, 213 extend toward the crankshaft 203
and are connected with the crankpin 207 by means of joints 214, 215, respec-
ti~ely. O~ing to the semicircular cross-section and the staggered installa-
tion, as well as the rotary motion of the two pistons about their longitudinal
axes always being in the same direction, the two piston shafts 212 and 213
do not interfere with each other as they move relatively.
The two joints 214 and 215 are of identical design and each has a
bushing or sleeve 216 which is mounted on the crankpin 207 in such a manner
that it can be shifted in the longitudinal direction and is pivotable. Two
jointed pins 217 project from each ~ushing 216 in the radial and diametrical
direction of the bushing and engage in boreholes 218 of the piston shafts 212,
10'79~ ~
213, respectively, as is particularly shown in Figure 6.
Figure 6 also shows recesses 219 and 220 in the piston shafts 212
or 213, respectively, which have the form of a slot in which the bushing 216
of the joints and the crankpin 207 are guided.
When the shaft journals 208 of the crankshaft Z03 rotate, the two
pistons 209 and 210, proceeding from the upper dead center position shown in
Figure 5, approach each other with the same speed. Furthermore, they rotate
around the longitudinal axis of the cylinder in the same direction and to
the same degree and that by 45 up to the mid-point of the stroke in the -;
example of the design as shown in Figure 6. The direction of rotation then
reverses at the mid-point of the stroke until again a reversing of the ;
direction of rotation is effected during the return stroke at the mid-point
of the stroke. Owing to the double motion of the translational motion of
both pistons 209 and 210, a mass equilibrium can be achieved together with the
counterbalance weights 206.
In order that the piston shafts 212 and 213 can support each other,
thus avoiding forces tending to urge the pistons against the cylinder wall,
they are provided with guides which extend in the longitudinal direction of
the shafts and engage into each other in a form-locking manner in a radial
direction. rn the em~odiment shown, they are desîgned as dovetail guides. For
the same purpose, the bushings 216 could also be rigidly connected with each
other or resiliently connected by means of a spring.
If, instead of the two pistons of the embodiment according to
Figures 5 and 6, one double piston each is provided, then, as shown in Figures
7 and 8, an extremely compact machine in the form of a star with four
generating or combustion chambers can be obtained together with a crankshaft,
the overall construction of which is designated generally by reference numeral
303. This crankshaft 303 is designed as the crankshaft 203. As is parti-
cularly shown in Figure 8, the longitudinal axis of the two cylinders 301
and 302, which are provided with a double piston 309, cuts through the longi-
. _ g _
107g64~
tudinal axis of the cylinders 301' and 302', with the latter being provided ;~
with a double piston 310 which has the same design as the double piston 309.
Furthermore, the two longitudinal axes of the cylinder pairs cut through the
longitudinal axis of the shaft journals 308 of the crankshaft 303 at a right
- angle. The double piston 309 has two cylindrical piston heads which are
connected with each other by an eccentrically arranged piston shaft 312, the
cross-sectional form of which is similar to two connected circular segments `~
as can be seen from Figure 7. This cross-sectional form, on the one hand is
due to the fact that the piston shaft is placed within the two cylinders 301
and 302 and, on the other hand, is intended to prevent interference with the
motion of the other piston shaft 313 which connects the piston heads of the
other double piston 310 with each other.
As is shown in Figure 7, the piston shaft 312 is provided with a
slot 319 which is axially located in its center section. The piston shaft 313,
which is of identical design, has a correspondingly designed slot 319'. The
two joints 314, 315, respectively, are located in these two slots and connect
the double pistons with the crankpin 307. The two joints 314, 315 can be -
rigidly connected with each other or, through an elastic intermediate element
such as a spring 322, for example, in order to be able to compensate for the
forces acting in the longitudinal direction of the crankpin and thus to avoid
the forcing of the pistons against the cylinder walls. The form of the slots
319, 319', which extend towards the outside and towards the inside in the
longitudinal direction of the piston shaft, is determined by the space requir- ~-
ed for the crankpin 307 and the joint and the width of the slots by the ;
dimensions of the bushings 316 which are placed on the crankpin in such a
manner that they can be shifted in the longitudinal direction and can be
pivoted, and which rest against the sides limiting the slots. As in the case
of the embodiment according to Figures 5 and 6, *wo jointed pins 317 project
from each bushing 316 in radial and diametrical directions and pivot in bore-
holes 318 of a respective piston shaft. The longitudinal axis of the bore-
- 10 -
lG796~7
.
holes 318 is located in a plane which is perpendicularly penetrated by the
longitudinal axis of the respective cylinders.
With a rotary movement of the shaft journals 308, both double pis-
tons 309 and 310 translate back~and-forth and also oscillate in a rotary
movement about their longitudinal axes.
In this instance, one of the double pistons is at mid-point of the
stroke when the other double piston is in its dead center position and vice~
versa. Correspondingly, one of the double pistons is at the point of the
reversal of the direction of rotation while the other double piston just
passes through the center line of its oscillating movement.
The example of a design shown in Figures 9 and 10 also represents
an arrangement of four cylinders 401, 402, 401', 402' in the form of a star.
Two double pistons 409, 410, respectively, are arranged in these cylinders
in such a way that they can be shifted in their respective longitudinal direc-
tion and pivoted about their longitudinal axes and are connected with a
common crankshaft 403 by means of the joints 414, 415, respectively. In
principle, the embodiment according to Figures 9 and 10 is the same as that
of the embodiment according to Figures 7 and 8.
A difference in comparison with the last-mentioned embodiment con-
sists of the fact that, as is particularly shown in Figure 9, the crankshaft
403 has a split crankpin, the two parts 407' and 407" of which are each
parallel to the longitudinal axis of the shaft journals 408 and are eccentri-
cally, but in opposite directions, arranged vis-a-vis this longitudinal axis
by the same amount. The two parts 407' and 407" of the crankpin are connec-
ted with each other by means of a connecting piece ~20 in the center between
two crank webs 404 and 405.
Each of the two parts 407' and 407" of the crankpin carries one of
the two joints 414 or 415, respectively, by means of which the crankpin is
connected with the eccentrically located piston shaft 412 or 413, respectively,
of the respective double piston 409, 410. The cross-section of the two
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1079~i4~7
identical piston shafts is shown in Figure 9 for the shaft 413. The two pis-
ton shafts 412 and 413 do not interfere with each other when performing their
combined longitudinal and rotary movements owing to the convex form of the
outer surface of the piston shaft towards the longitudinal axis of the
respective cylinders which cuts through the longitudinal axis of the two other
cylinders at a right angle as well as the axis defined by the shaft journals
408.
The two identical joints 414 and 415 each have a cylindrical bushing
416 which is provided with a borehole axially penetrating it in the radial
direction to receive the respective part of the crankpin. The two front faces
of the bushing 416 confront one or the other piston head of the respective
double piston and rest against plane bearing surfaces of the piston shaft. It
goes without saying that antifriction bearings can also be utili~ed.
As is shown in Figure 9 in connection with the joint 415, the outer
surface of the bushing rests against two correspondingly curved guide surfaces
of the piston shaft. In this manner, the bushing 416 permits a rotary motion
; of the crankpin part in the borehole which receives it, as well as a rotation
around its longitudinal axis relative to the piston shaft. Therefore, with
; one rotation, the crankshaft 403 causes the two double pistons 409 and 410
not only to perform a translational motion but, simultaneously, also an
oscillating rotary motion around the longitudinal axis of the cylinders re-
ceiving them, as is also the case of the embodiment according to Figures 7
and 8.
It is implied by means of the bearings 421 that the crankshaft 403
can also be supported in the area of the crank webs 404 and 405 which are
designed as disks.
The embodiment according to Figures 11 and 12 is distinguished from
the other embodiments by two adjacent double-acting pistons 1 which have a
common crankshaft 2. This distinction, however, is of subordinate importance,
because the features representing the substantial distinction can likewise
- 12 -
107~6~
be incorporated in embodiments which have a different number of pistons, or
double-acting pistons; for example, merely one piston, or one double-acting
piston.
The embodiment of Figures 11 and 12 is of particular significance,
in that the centre of gravity of the piston 501 of each cylinder 503, which
has been illustrated without the inlet and the outlet openings, is off-centre
by approximately half the diameter of the cylinder. The spacing could be
made even larger, if desired. This is achieved in that the piston shaft 50~4 -
in the case of a double-acting piston both parts of the shaft - is (are) pro-
vided with a slot 505 which is concentrically disposed about the longitudinal
axis of the cylinder 503 and open in the direction away from the crankshaft
502. This slot 505 engages the wall of the cylinder 503, as shown in Figure
; 11. The dimensions of the slot 505 have been selected in such a manner that
it permits a relative movement of the cylinder wall inside the slot 505 in
circumferential as well as in longitudinal direction of the piston.
The positioning of the parts of the piston shaft 504 outside the
cylinder 503 results in a substantial distance of the centre of gravity of the
piston from the longitudinal axis of the cylinder. According to the present
embodiment, the centre of gravity is disposed approximately in the surface
defined by the cylinder 503. Furthermore, the positioning of part of the
piston shaft 504 outside the cylinder 503 is advantageous, because this
eliminates the need for the cylinder 503 to support the piston, upon which a
force acts in radial direction because of the inclined position of the piston
head 501'. The support for the piston shaft 504 can now be arranged outside
the cylinder. According to the present embodiment, this support and the
guidance of the double piston 501 being afforded by the support, is achieved
; with the aid of two uniform plates 506 which are disposed parallel to one an-
other and sy~metrical to the crank shaft 502. These two plates 506 are each
provided with two openings, through which one each of the cylinders 503 and
the pertinent piston shaft 504 extend. One further opening accommodates a
- 13 -
107964~7
bearing body 507, wherein one of the shaft journals 508 of the crank shaft
502 is disposed. Further bearing bodies 509 for the remaining shaft journals
are each disposed in the space between two cylinders 503 which are coordinated
with the same double piston 501 and thus permit a small space between the two
double pistons. In the same fashion as the piston shafts 504, projections
509' of the bearing bodies 509 extend through the openings in the plates 506
so as to form a support for each of the cylinders 503.
The joint which connects the double piston 501 and the crankpin 510
of the crank shaft 502 is provided with a longitudinally displaceable sleeve
511, bearing two diametrically disposed pins 512 which radially project from '
the sleeve. These pins 512 rotatably engage in blind bores in the piston
shaft 504.
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