US3604402A - Piston mechanism - Google Patents

Piston mechanism Download PDF

Info

Publication number
US3604402A
US3604402A US3604402DA US3604402A US 3604402 A US3604402 A US 3604402A US 3604402D A US3604402D A US 3604402DA US 3604402 A US3604402 A US 3604402A
Authority
US
Grant status
Grant
Patent type
Prior art keywords
pistons
piston
shaft
spring
cam
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Inventor
Ernst Hatz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MOTORENFABRIK HATZ KG
Original Assignee
MOTORENFABRIK HATZ KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Grant date

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02BINTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00Other engines
    • F02B75/16Engines characterised by number of cylinders, e.g. single-cylinder engines
    • F02B75/18Multi-cylinder engines
    • F02B75/22Multi-cylinder engines with cylinders in V, fan, or star arrangement
    • F02B75/222Multi-cylinder engines with cylinders in V, fan, or star arrangement with cylinders in star arrangement
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01BMACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
    • F01B9/00Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups
    • F01B9/04Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups with rotary main shaft other than crankshaft
    • F01B9/06Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups with rotary main shaft other than crankshaft the piston motion being transmitted by curved surfaces
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01BMACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
    • F01B9/00Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups
    • F01B9/04Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups with rotary main shaft other than crankshaft
    • F01B9/06Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups with rotary main shaft other than crankshaft the piston motion being transmitted by curved surfaces
    • F01B2009/061Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups with rotary main shaft other than crankshaft the piston motion being transmitted by curved surfaces by cams
    • F01B2009/065Bi-lobe cams
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02BINTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00Other engines
    • F02B75/02Engines characterised by their cycles, e.g. six-stroke
    • F02B2075/022Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
    • F02B2075/025Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02BINTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00Other engines
    • F02B75/16Engines characterised by number of cylinders, e.g. single-cylinder engines
    • F02B75/18Multi-cylinder engines
    • F02B2075/1804Number of cylinders
    • F02B2075/1816Number of cylinders four
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02BINTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B3/00Engines characterised by air compression and subsequent fuel addition
    • F02B3/06Engines characterised by air compression and subsequent fuel addition with compression ignition
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00Machine element or mechanism
    • Y10T74/18Mechanical movements
    • Y10T74/18056Rotary to or from reciprocating or oscillating
    • Y10T74/18296Cam and slide

Abstract

A piston mechanism having preferably one or two pairs of opposed cylinders with reciprocating pistons therein. A shaft located between the pistons includes diametrically opposed cams thereon for directly and drivingly engaging the pistons. Springs urge the pistons against the cam parts and the spring can also operate a scavage air feeder. Valves can be operated by further cams mounted on the shaft.

Description

United States Patent Inventor Ernst Hatz Ruhstorf, Germany Appl. No. 851,944

Filed Aug. 21, 1969 Patented Sept. 14, 1971 Assignee Motorenfabrik Hatz KG Ruhstorf, Germany Priority Sept. 12, 1968 Germany PISTON MECHANISM 9 Claims, 8 Drawing Figs.

US. Cl 123/56 C, 74/55, 92/72, 123/43 C, 123/197 Int. Cl ..F02b 75/24, F02b 75/32 Field of Search 123/56 C, 44 E, 43 C, 197, 197 A; 92/72, 73; 74/55 References Cited UNITED STATES PATENTS Stewart 123/44 E) 1,774,087 8/1930 Dunn 123/56 (C) X 1,784,902 12/1930 Maurais... 74/55 1,904,680 4/1933 Ferry 123/56 (C) 2,198,759 4/1940 Cadet 92/72 X 2,249,951 7/1941 Fulton 74/55 FOREIGN PATENTS 603,720 6/1948 Great Britain 123/56 (C) 20,518 1/1918 France 123/44 (E) 1,252,583 12/1960 France 92/73 826,839 1/1938 France 74/55 426,680 3/1926 Germany 123/56 (C) Primary Examiner-Wendell E. Burns Attorney-Larson, Taylor and Hinds ABSTRACT: A piston mechanism having preferably one or two pairs of opposed cylinders with reciprocating pistons therein. A shaft located between the pistons includes diametrically opposed cams thereon for directly and drivingly engaging the pistons. Springs urge the pistons against the cam parts and the spring can also operate a scavage air feeder. Valves can be operated by further cams mounted on the shaft.

PA'IFNH'HSPPMIQII 3.604.402

sum 1 or 6 INVENTOR ERNST HATZ ATTORNEYS PATENTED SEPI 419m SHEET t [1F 6 ATTORNEYS PISTON MECHANISM BACKGROUND OF THE INVENTION This invention relates to piston mechanisms of the type including at least one pair of opposed pistons and cylinders and including a central shaft drivingly engageable with the pistons.

In piston mechanisms of the present type, particularly in internal combustion engines, the coupling between the pistons and the central shaft is usually characterized by a connecting rod system. However, this conventional connecting rod system has several disadvantages. It is a comparatively complicated structure and requires substantial space for its operation. In addition, this arrangement has the further disadvantage that the coupling elements are normally fairly large and thus produce large oscillations as they constantly change their direction during the operation of the engine. These oscillations thereby result in undesirable vibrations and moreover they lead to excessive wear of the engine parts and excessive loading of the bearings.

SUMMARY OF THE INVENTION It is a purpose of the present invention to provide a piston mechanism such as an internal combustion engine or the like wherein the above described disadvantages are eliminated. It is thus a further purpose of this invention to provide a mechanism of the type described which is substantially free from vibrations and which is compact in size and which operates without overloading the bearings.

This purpose is achieved in accordance with the present invention by providing at least one and possibly more pairs of diametrically opposed piston and cylinder units located on opposite sides of a rotating shaft and providing on the shaft a cam comprising cam parts mounted on diametrically opposite sides of the shaft axis for rotation with the shaft. In accordance with a feature of the present invention, the driving force is transferred between the pistons and the cams by direct engagement of these members, either through sliding surface contact or rolling surface contact wherein the driving force is exerted in a direction generally parallel to the direction of reciprocation of the pistons. Thus, conventional crank shafts, connecting rods, etc., are completely eliminated.

In a preferred embodiment of the invention, resilient means are provided for urging the pistons against the cam parts. This resilient means may comprise a wire-type spring member grasping the pistons at its two ends and having its central part located in the central space between the pistons in the vicinity of the shaft. For convenience the wire-type spring may be at least partially wound about the shaft.

When applying the present invention to a two-stroke internal combustion engine, the spring need only ensure movement of the pistons against the cams when the engine is stopped and upon starting of the engine. Consequently, in this environment the spring need not be very powerful. In the case of a fourstroke internal combustion engine, however, the spring must also assure contact between the piston and the cam parts during a particular operating phase, and in this case the spring will have to be more powerful.

In accordance with a further feature of the invention, the resilient means may comprise a steel strip or the like connected to one piston at one end and connected at its other end to a separate resilient means or to another part of the engine which is moveable through a cycle opposite from that to which the said strip is attached. For example, in an embodiment having two pairs of pistons arranged at right angles to each other, the strip may be attached at its two ends to one piston of each pair, the intermediate part of the strip being wound about the shaft.

In accordance with a further feature of the invention, in the case of a two-stroke internal combustion engine, the spring may be arranged to facilitate feeding of scavaging air into the cylinders. In this case the moveable part of the spring may be made to act against a resilient member such as a diaphragm or the like to cause pumping of air into the cylinders concurrent with reciprocating movement of the piston.

In accordance with another feature of the invention, the same driving shaft may have additional cams mounted thereon for controlling the fluid relative to the cylinders. For example, the cams may operate valves, injection nozzles or the like for controlling the flow of fuel and or air to and from the cyliners.

Thus, it is a purpose of this invention to provide a new and improved piston mechanism.

It is another object of this invention to provide a new and improved piston mechanism which is substantially vibration free and which is relatively compact.

It is another object of this invention to provide a new and improved piston mechanism having diametrically opposed cylinders with reciprocating pistons therein which are drivingly engageable with cam parts mounted on and rotatable with a shaft located between the pistons.

It is another object of this invention to provide a new and improved piston mechanism having opposed pistons drivingly engaging a shaft through cams mounted on the shaft and including novel arrangements of resilient means for assuring contact between the pistons and the cams.

Other objects and the attendant advantages of the present invention will become apparent from the detailed description to follow together with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS There follows a detailed description of preferred embodiments to be read together with accompanying drawings. It is to be understood, however, that the description and the drawings are provided merely to illustrate and describe preferred embodiments of the invention.

FIG. 1 is a sectional view of a piston mechanism constructed in accordance with the features of the present invention.

FIG. 2 is a side elevational view taken from the left-hand side of FIG. 1.

FIG. 3 is a horizontal sectional view taken along line 3-3 of FIG. 2.

FIG. 4 is a partial cross-sectional view similar to FIG. I but showing a modification of the invention.

FIG. 5 is a partial cross sectional view similar to FIG. I but showing another modification of the invention.

FIG. 6 is a side elevational view of another embodiment with a portion shown in section and taken through line 6-6 of FIG. 8.

FIG. 7 is a sectional view taken through line 77 of FIG. 8.

FIG. 8 is a sectional view taken through line 8 -8 of FIG. 7. DETAILED DESCRIPTION OF THE PREFERRED EM- BODIMENTS In the description to follow, like numerals represent like elements throughout the several views. Further, in FIGS. 4 and 5, certain elements similar to those in FIG. 1 are increased by and 200, respectively. Further, in the embodiment of FIGS. 6 through 8, elements similar to those in FIGS. 1 through 4 are raised by 300.

Referring to FIGS. 1-3, there is shown a two-cylinder twostroke internal combustion engine. It comprises a cylinder block I in which are formed two diametrically opposed cylinders la, lb with an inner chamber 1c between them. A driving shaft 2 is mounted and axially centered in the unit through the agency of bearings 3, 4 and has a clutch slot 2a for positive engagement with any unit (not shown) to be driven. 5 and 6 depict seals for sealing the inner chamber 10 from the exterior. The cylinders are provided at their peripheries with cooling fins 1d, 1e, and a cylinder head 7a, 7b respectively, is fastened to the block 1 at the respective ends of the cylinders. Spark plugs 8a, 8b of conventional form are secured in each cylinder head. A cover I1 is secured to one narrow side If of block I by screws, this cover carrying carburetter 9 and suction flap valve 10. The driving shaft 2 also drives the rotary part 12 of an electromagnetic spark distributor, which has a number of blades 13 additionally carried at the periphery thereof serving as an air blower for cooling parts Id, 1e. The fixed or immobile part 12a of the distributor is secured to the engine block 1. The drive transmission from shaft 2 to the rotary part 12 may for example be implemented by a key 130.

Also provided in cylinder block 1, in the vicinity of cylinders la, 1b are apertures lsa, Isb which conduct the flow of scavaging air through the cylinders. Arranged in each cylinder is a piston 14a, 14b which is reciprocable in the direction towards the axial center of the unit. The coupling between pistons 14 and driving shaft 2 is, however, not in the traditional manner through a connecting rod but as follows:

Transversely mounted in each of the pistons 14a, 14b is a roller pintle 15a, 15b on which is rotatably mounted, preferably through the agency of needle bearings (not shown), a roller 16a, 16b respectively. Each of these rollers is engaged by a cam comprising cam parts 2na, 2nb mounted on shaft 2. These cam parts may be in one piece with the shaft or may be made separately and then firmly fastened thereto. Cam parts 2na, 2nb are disposed diametrically opposite from one another relative to the shaft axis so that they cooperate alternately with the rollers 16a, 16b of the pistons when shaft 2 rotates.

A return spring 17 of resilient wire form is disposed in the inner chamber 1c and has ends 17a, 17b curved and each engaging and thus held to one of the pintles 15a, 15 b. The resilient limb 170s of this spring is shaped to provide a central multiturn section 17cm in the vicinity of shaft 2, with limbs 17a: extending therefrom transversely through the inner chamber 11: and united at 170' with the other spring part l7bz which is similarly shaped and arranged at the other side of cams Zna, 2hb. Spring 17 is connected at 17d to a resilient diaphragm 18 by means of a rivet 19 or the like. With the arrangement of spring 17 described above, when piston 14a moves outwardly, that is, into its upper dead center position OT, limbs 1711s and 17hr are distended so that the central limb portions l7az, 17b: move in the direction of the arrow A in FIG. 1. At the same time the part 17d makes a movement in the same sense in the direction of arrow B, wherefore diaphragm 18 is pushed out to the right (FIG. 2). When piston 14 moves inwards, that is to say into the lower dead center position UT, limbs 17as, I7bs draw together under the effect of the resilience of spring 17 and the spring portion 17ac, 17bc, 17d now perform a movement in the reverse direction to the left (FIG. 1). During this phase diaphragm 18 is pulled in again. This motion of diaphragm 18 in snychronism with the inward movement of the pistons is used for a pumping action, whereby the parts 17d and 18 act as a charging pump or blower. This increases the volume of suction and scavaging air and the suction or scavaging air inside chamber 10 is subjected to a useful precompression (in other constructions a feed pump or the like can be connected to the spring portion 17:1, in place of diaphragm 18, for the purpose indicated above).

The operation of the arrangement described simulates that of a known two-stroke engine with an extraneous ignition, and thus it is unnecessary to explain further the functioning in a two-stroke cycle of this nature. A difference is to be found, however, in the fact that the two pistons operate with a simultaneous stroke, that is to say they simultaneously move outward and reach the OT position or inward reach the UT position. They also differ in that in the present arrangement the force between the shaft 2 and the pistons 14a, 14b is transmitted through cams Zna, Znb only. Engagement between ele ments 14a, 14b on the one hand the elements Zna and 2nb on the other is ensured at any moment in the two strokes (up to a certain number of rotations), by either the pressure of the cam or the counter pressure within the cylinders acting on each piston.

An optimum driving coupling is ensured when the forces acting on a piston are equal to or less than the pressure exerted on the piston from the combustion chamber. In the example illustrated it will be assumed that the performance curve of each piston, which is calculated from the diameter of the drive rollers, the outside diameter of the cam and the curvature of the entry and exit flanks of the cam and the base circle of the latter is a true sine curve. Thus a satisfactory drive coupling is ensured as long as the formula P=n'w -r'sin a is adhered to, the factors of the above being as follows:

= pressure on the pistons.

n twice the rate of rotation of the driving shaft 107 twice the angular speed of the driving shaft.

r= half the height of the cams.

o twice the angle of rotation of the driving shaft.

The pistons 14a, 14b are accelerated during the upward motion (from UT to OT) up to half the stroke, that is to say at least as long as the openings lsa, lsb are open. As soon as these openings are covered by the pistons a counterpressure is developed in each cylinder la, lb which augments the pressure of the pistons 14a, 14b through the rollers 16a, 16b against the associated cams 2na, 2nb. As soon as the travel exceeds the half stroke the movement of the piston is slowed down, but the counterpressure at this point is already greater than the forces imposing the delay, so that even at this phase of the upward movement the power transmission is continuously maintained. The maximum delaying forces act on the piston in the OT position. At this instant, however, the counter forces exerted from the cylinder are at a maximum.

As regards the downward movement of the pistons (from OT to UT) conditions analogous to those referred to above in relation to the upward movement will apply. Thus a power coupling between the piston and the cams continuously prevails even during the downward movement.

As has been explained in the foregoing, the forces and counter forces which act on each piston in the embodiment being described are so related to one another that without more a nonpositive coupling is continuously applied between the pistons and cams, until a critical rate of rotation is achieved. The tension spring 17 is thus not per se necessary during the running of the engine. Its only function is to assist the starting of the stationary internal combustion engine in cases where both pistons may by chance come to rest in position OT. In such instances, when starting up the spring must move the two pistons towards position UT on movement of the cams to ensure engagement between the cooperating parts. In such instances the spring has merely to overcome the friction between the pistons and cylinders and the relatively small pressure in chamber 1c, and in some instances the weight of the pistons (in the event that the internal combustion engine is arranged so that the axis of the pistons are vertical). The spring forces required here are however very small, so that spring 17 need not be very strong.

When the return spring does not have to operate a scavaging air charging device, the form of this spring can be even more simple than that illustrated in FIG. 1, as shown by the example illustrated in FIG. 4. In this case a relatively weak spring 117 is arranged at each side of the cams 2na, 2nb. With this means, not only is the return of the pistons 14 ensured, but the pistons will also be held in their correct running positions relative to cams 2na, Znb by the action of the two springs 117 on pintles 15a and 15b. Instead of using a return spring, each piston can be connected with one end of at least one steel strip 217 as indicated in FIG. 5, the other end being anchored to a part which is movable in a cycle opposed to that of the piston, for example to a fixedly mounted rotational roller 218 which is turned in the direction of arrow C by means of a helical spring 219. As a result, during the movement of the piston 14a to position UT the strip 217 will be rolled around roller 218 under the action of spring 219 and will roll off roller 218 again when the piston moves towards GT in opposition to spring 219. Alternatively, a steel wire or a chain may be used for the same purpose in place of a steel strip in this type of return of the piston.

The features illustrated in FIGS. 1 to 5 could be used also in similar form in a single cylinder internal combustion engine if for example the piston 14b is not subject to the pressure in a combustion chamber lb but is merely urged, through its roller 16b against its associated cam 2nb or Zna under the action of a correspondingly powerful spring. This piston 14b would then merely have the function of a member for returning working piston 14a.

The embodiment of the invention illustrated in FIGS. 6 to 8 relates to a four-stroke internal combustion engine with extraneous ignition. In contrast to the embodiment of FIGS. 1 to 3, this embodiment has pairs of pistons offset at 90 to one another. The power transmission, without connecting rods, between the driving shaft and the pistons is here the same as in the first embodiment, so that a further description of this phase of the operation need not be repeated here.

The elements in this embodiment are again devised so that the cam rise follows a sine curve. Since in the case ofa rapidly running four-stroke engine inertial forces are heavy and, on the other hand, the pressures or counter pressures applied against each piston from the cylinder are very small, or even slightly negative (suction stroke) in certain operating phases, an expedient dictating a positive return movement is necessary for each piston to ensure engagement between the piston and cam. A preferred return means designed for this purpose is a spring steel strip 3170 which is connected to the piston 314a of one pair, passes around shaft 302 at 30214 and is then connected to piston 3140 of the other pair. A second strip 317b is similarly arranged between the other two pistons 314b and 314d. Since the two strip-connected pistons operate in opposed cycles, the strip length always remains the same (assuming D=d).

When the diameter D of the relevant portion of the shaft must be greater than the diameter d, the resultant comparative motions of pistons 314a and 314c may be balanced by an appropriate slight modification of the rising or falling flanks of cams 302na, 302nb, with the base circle and the top'circles of these cams remaining the same.

A spring steel wire or a chain or the like may be used in place of the spring steel strip referred to. Moreover two connecting elements of the kind referred to could be connected in symmetrical fashion to a single piston, should it be found necessary to do so, for example for parallel guidance of the piston or its roller relative to the cam.

Two further control cams 302i and 3022 are provided on drive shaft 302 alongside cam 30211 for operating the inlet valves 320a, 320b, 3200, 320d or the exhaust valves 321a, 321b, 321e, 321d through interposted transmission elements of known type.

In the case of engines having self-coupling (Diesel engines) a third control cam, may be provided on shaft 302, for example for controlling injection nozzles.

ln this embodiment use is made of one control cam only for a specific group of control elements, so that the firing sequence is a, b, c, d. Where use is made of a number of control cams for one group, for example for inlet valves, the firing sequence may however, be varied very simply in any appropriate way.

In all the embodiments of the invention described, no lateral and no continuously alternating torques are applied to the driving shaft, to that the occurrence of detrimental oscillations in the drive is inhibited. Moreover the transmission forces between the pistons and cams are always normal to the cams and alternate in the same cycle at both sides so that no, or only very minimal bending forces are applied to the shaft. The latter therefore need not be very robust and can be mounted in small main bearings only. Stated differently, the load on the bearings is relatively small. More importantly, the number and form of the driving cams on the shaft can be suited to the transmission ratio required. That is, instead of using the ratio 1:2 in the example illustrated, a reduction ratio 1:3 or 1:4 can be used.

the elements (pistons, shaft, cams, valves etc.) which are required to construct the piston engine in accordance with the present invention have the conventional form, so that they can be made by prior manufacturing means or methods, and for example even by a series manufacturing process, and be achieved.

Although the invention has been described in considerable detail with respect to preferred embodiments thereof, it should be apparent that the invention is capable of numerous modifications and variations apparent to those skilled in the art without departing from the spirit or scope of the invention. For example, the number of pistons is not limited to the number illustrated, and the device may be applied to different types of piston mechanisms such as a pump wherein the shaft drives the pistons.

lclaim:

l. A piston mechanism comprising at least one pair of diametrically opposed cylinders, a reciprocating piston in each cylinder, a shaft located between said pistons, and driving means for placing said pistons and said shaft into driving relationship with each other, said driving means comprising at least one pair of cam parts mounted on diametrically opposite sides of the axis of the said shaft for rotation with said shaft, said cam parts being engageable with said pistons such that the driving force between the pistons and the shaft is transmitted through contact between said cam parts and said pistons in a direction generally parallel to the direction of movement of the pistons and including resilient means having a movable part, said resilient means continuously acting on the pistons for urging the pistons against the cam parts, wherein said piston mechanism is a two-stroke internal combustion engine including pumping means for pumping scavanging air to said cylinders, the last said means being operated by said resilient means as the movable of said resilient means moves with the pistons during the reciprocation of the pistons.

2. A piston mechanism according to clam 1 wherein the cam parts are nonpositively connected to said pistons such that the pistons and the cam parts can be moved independently of each other.

3. A piston mechanism according to claim 1 wherein the cam parts engage the pistons directly such that said contact is sliding contact.

4. A piston mechanism according to claim 1 wherein the pistons include rolling elements reciprocating therewith and wherein the cam parts engine the rolling elements whereby said contact is rolling contact.

5. A piston mechanism according to claim 1 including guide means for preventing rotary movement of each piston within its respective cylinder.

6. A piston mechanism according to claim 1 including further cams mounted on said shaft for rotation therewith for controlling the flow of fluids in said mechanism relative to said cylinders.

7. A piston mechanism according to claim 6 including control valves for controlling the flow of fluids into and out of said cylinders, movement of said valves being controlled by said further cams.

8. A piston mechanism according to claim 1, wherein said resilient means comprises at least one spring member having its central part located between the pistons and having one opposite end engaging each of the opposed pistons to urge the same in the direction towards the cam part, the movable part of said spring member reciprocating with said pistons operably engaging a movable part of said pumping means to feed said scavanging air into the cylinders.

9. A piston mechanism according to claim 8, said movable part of said pumping means being a diaphragm, wherein when the pistons move toward said shaft the diaphragm is moved by said spring member to cause scavanging air to be fed into the cylinders. I

Claims (9)

1. A piston mechanism comprising at least one pair of diametrically opposed cylinders, a reciprocating piston in each cylinder, a shaft located between said pistons, and driving means for placing said pistons and said shaft into driving relationship with each other, said driving means comprising at least one pair of cam parts mounted on diametrically opposite sides of the axis of the said shaft for rotation with said shaft, said cam parts being engageable with said pistons such that the driving force between the piStons and the shaft is transmitted through contact between said cam parts and said pistons in a direction generally parallel to the direction of movement of the pistons and including resilient means having a movable part, said resilient means continuously acting on the pistons for urging the pistons against the cam parts, wherein said piston mechanism is a twostroke internal combustion engine including pumping means for pumping scavanging air to said cylinders, the last said means being operated by said resilient means as the movable of said resilient means moves with the pistons during the reciprocation of the pistons.
2. A piston mechanism according to clam 1 wherein the cam parts are nonpositively connected to said pistons such that the pistons and the cam parts can be moved independently of each other.
3. A piston mechanism according to claim 1 wherein the cam parts engage the pistons directly such that said contact is sliding contact.
4. A piston mechanism according to claim 1 wherein the pistons include rolling elements reciprocating therewith and wherein the cam parts engine the rolling elements whereby said contact is rolling contact.
5. A piston mechanism according to claim 1 including guide means for preventing rotary movement of each piston within its respective cylinder.
6. A piston mechanism according to claim 1 including further cams mounted on said shaft for rotation therewith for controlling the flow of fluids in said mechanism relative to said cylinders.
7. A piston mechanism according to claim 6 including control valves for controlling the flow of fluids into and out of said cylinders, movement of said valves being controlled by said further cams.
8. A piston mechanism according to claim 1, wherein said resilient means comprises at least one spring member having its central part located between the pistons and having one opposite end engaging each of the opposed pistons to urge the same in the direction towards the cam part, the movable part of said spring member reciprocating with said pistons operably engaging a movable part of said pumping means to feed said scavanging air into the cylinders.
9. A piston mechanism according to claim 8, said movable part of said pumping means being a diaphragm, wherein when the pistons move toward said shaft the diaphragm is moved by said spring member to cause scavanging air to be fed into the cylinders.
US3604402A 1968-09-12 1969-08-21 Piston mechanism Expired - Lifetime US3604402A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE19681776054 DE1776054A1 (en) 1968-09-12 1968-09-12 piston engine

Publications (1)

Publication Number Publication Date
US3604402A true US3604402A (en) 1971-09-14

Family

ID=5702819

Family Applications (1)

Application Number Title Priority Date Filing Date
US3604402A Expired - Lifetime US3604402A (en) 1968-09-12 1969-08-21 Piston mechanism

Country Status (4)

Country Link
US (1) US3604402A (en)
DE (1) DE1776054A1 (en)
FR (1) FR2017889A1 (en)
GB (1) GB1270983A (en)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4092829A (en) * 1975-11-06 1978-06-06 The United States Of America As Represented By The Secretary Of The Army Balanced compressor
US4545336A (en) * 1984-10-01 1985-10-08 Bcds Corporation Engine with roller and cam drive from piston to output shaft
US4592309A (en) * 1981-05-28 1986-06-03 Williams Gerald J Internal combustion engine
US4697552A (en) * 1985-08-23 1987-10-06 Naucho Proizvodsvena Laboratoria Za Dvigateli S Vatreshno Gorene Modular internal combustion engine
US5035221A (en) * 1989-01-11 1991-07-30 Martin Tiby M High pressure electronic common-rail fuel injection system for diesel engines
US5218933A (en) * 1989-11-28 1993-06-15 Environmental Engines Limited Internal combustion engines
US5605134A (en) * 1995-04-13 1997-02-25 Martin; Tiby M. High pressure electronic common rail fuel injector and method of controlling a fuel injection event
US5634441A (en) * 1996-01-16 1997-06-03 W. Parker Ragain Power transfer mechanism
US5647308A (en) * 1994-09-13 1997-07-15 Pomezia S.R.L. Crank mechanism system for the transformation of reciprocating linear motion into rotary motion, particularly suitable for reciprocating endothermic engines
US6244832B1 (en) * 1998-04-09 2001-06-12 Robert Bosch Gmbh Radial piston pump for high-pressure fuel delivery
US6764285B1 (en) * 1999-02-22 2004-07-20 Robert Bosch Gmbh Hydraulic pump unit
US20070068468A1 (en) * 2005-09-27 2007-03-29 Irick David K Rotary to reciprocal power transfer device
US20070227347A1 (en) * 2005-05-16 2007-10-04 Fsnc, Llc Self-compensating cylinder system in a process cycle

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9309372D0 (en) * 1993-05-06 1993-06-16 Owen Stephen W Internal combustion cam engine

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR20518E (en) * 1916-09-14 1918-05-08 Amedee Weidknecht Combustion engine applicable to all vehicles and for using the burned gas
US1394587A (en) * 1920-07-31 1921-10-25 R H S Motors Inc Rotary gas engine or motor
DE426680C (en) * 1923-11-14 1926-03-15 Julius Herrmann Two-stroke internal combustion engine having pairs of cylinders and opposed pistons
US1774087A (en) * 1928-09-15 1930-08-26 William G Dunn Double-cam motor
US1784902A (en) * 1929-10-22 1930-12-16 Joseph V Maurais Power-shaft connection for internal-combustion engines
US1904680A (en) * 1930-04-18 1933-04-18 Ferry S Inc Radial cam type internal combustion engine
FR826839A (en) * 1937-04-19 1938-04-11 Device for transmitting torques
US2198759A (en) * 1936-05-06 1940-04-30 Distributeurs Automatiques S E Fluid metering device
US2249951A (en) * 1939-12-04 1941-07-22 M S Kingston Energy transmission means
GB603720A (en) * 1944-10-20 1948-06-22 Henri Convert Improvements in or relating to the driving gear of opposed-piston two-stroke internal-combustion engines
FR1252583A (en) * 1960-04-04 1961-01-27 Machine steering hydraulic parallel cylinders

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR20518E (en) * 1916-09-14 1918-05-08 Amedee Weidknecht Combustion engine applicable to all vehicles and for using the burned gas
US1394587A (en) * 1920-07-31 1921-10-25 R H S Motors Inc Rotary gas engine or motor
DE426680C (en) * 1923-11-14 1926-03-15 Julius Herrmann Two-stroke internal combustion engine having pairs of cylinders and opposed pistons
US1774087A (en) * 1928-09-15 1930-08-26 William G Dunn Double-cam motor
US1784902A (en) * 1929-10-22 1930-12-16 Joseph V Maurais Power-shaft connection for internal-combustion engines
US1904680A (en) * 1930-04-18 1933-04-18 Ferry S Inc Radial cam type internal combustion engine
US2198759A (en) * 1936-05-06 1940-04-30 Distributeurs Automatiques S E Fluid metering device
FR826839A (en) * 1937-04-19 1938-04-11 Device for transmitting torques
US2249951A (en) * 1939-12-04 1941-07-22 M S Kingston Energy transmission means
GB603720A (en) * 1944-10-20 1948-06-22 Henri Convert Improvements in or relating to the driving gear of opposed-piston two-stroke internal-combustion engines
FR1252583A (en) * 1960-04-04 1961-01-27 Machine steering hydraulic parallel cylinders

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4092829A (en) * 1975-11-06 1978-06-06 The United States Of America As Represented By The Secretary Of The Army Balanced compressor
US4592309A (en) * 1981-05-28 1986-06-03 Williams Gerald J Internal combustion engine
US4545336A (en) * 1984-10-01 1985-10-08 Bcds Corporation Engine with roller and cam drive from piston to output shaft
US4697552A (en) * 1985-08-23 1987-10-06 Naucho Proizvodsvena Laboratoria Za Dvigateli S Vatreshno Gorene Modular internal combustion engine
US5311850A (en) * 1989-01-11 1994-05-17 Martin Tiby M High pressure electronic common-rail fuel injection system for diesel engines
US5035221A (en) * 1989-01-11 1991-07-30 Martin Tiby M High pressure electronic common-rail fuel injection system for diesel engines
US5218933A (en) * 1989-11-28 1993-06-15 Environmental Engines Limited Internal combustion engines
US5647308A (en) * 1994-09-13 1997-07-15 Pomezia S.R.L. Crank mechanism system for the transformation of reciprocating linear motion into rotary motion, particularly suitable for reciprocating endothermic engines
US5605134A (en) * 1995-04-13 1997-02-25 Martin; Tiby M. High pressure electronic common rail fuel injector and method of controlling a fuel injection event
US5634441A (en) * 1996-01-16 1997-06-03 W. Parker Ragain Power transfer mechanism
US6244832B1 (en) * 1998-04-09 2001-06-12 Robert Bosch Gmbh Radial piston pump for high-pressure fuel delivery
US6764285B1 (en) * 1999-02-22 2004-07-20 Robert Bosch Gmbh Hydraulic pump unit
US20070227347A1 (en) * 2005-05-16 2007-10-04 Fsnc, Llc Self-compensating cylinder system in a process cycle
US7610894B2 (en) * 2005-05-16 2009-11-03 Fsnc, Llc Self-compensating cylinder system in a process cycle
US20070068468A1 (en) * 2005-09-27 2007-03-29 Irick David K Rotary to reciprocal power transfer device
US7475627B2 (en) 2005-09-27 2009-01-13 Ragain Air Compressors, Inc. Rotary to reciprocal power transfer device

Also Published As

Publication number Publication date Type
DE1776054A1 (en) 1970-11-12 application
GB1270983A (en) 1972-04-19 application
FR2017889A1 (en) 1970-05-22 application

Similar Documents

Publication Publication Date Title
US3584610A (en) Internal combustion engine
US3144007A (en) Rotary radial-piston machine
US6058901A (en) Offset crankshaft engine
US5927236A (en) Variable stroke mechanism for internal combustion engine
US5158047A (en) Delayed drop power stroke internal combustion engine
US5992356A (en) Opposed piston combustion engine
US6230671B1 (en) Variable compression and asymmetrical stroke internal combustion engine
US5243938A (en) Differential stroke internal combustion engine
US5431130A (en) Internal combustion engine with stroke specialized cylinders
US4022167A (en) Internal combustion engine and operating cycle
US4517931A (en) Variable stroke engine
US3304923A (en) Engine
US4066049A (en) Internal combustion engine having a variable engine displacement
US3868932A (en) Reciprocating engine
US5007385A (en) Crankless engine
US6453869B1 (en) Internal combustion engine with variable ratio crankshaft assembly
US3895620A (en) Engine and gas generator
US5146884A (en) Engine with an offset crankshaft
US5813372A (en) Axial piston rotary engine
US4010611A (en) Compression-expansion power device
US4078450A (en) Apparatus for shock mounting of piston rods in internal combustion engines and the like
US5156121A (en) Piston-connecting rod assembly
US3274982A (en) Two-cycle two-cylinder internal combustion engine
US3866581A (en) Opposed piston engine
EP0708274A1 (en) Crank device and machine device