US3818886A - Rotary internal combustion engine - Google Patents

Abstract

A rotary-piston internal combustion engine having an annular compression cylinder and a separate annular combustion cylinder with one or more passages interconnecting the two cylinders and with valves dividing the compression cylinder into intake and compression chambers and the combustion cylinder into combustion and exhaust chambers. At least one piston is mounted within each cylinder and is rigidly mounted on a drive shaft common to the pistons for both cylinders, such that it revolves within its corresponding cylinder. The piston in the compression cylinder compresses a charge of gaseous fuel mixture into the passage between the cylinders, from which the gases expand into the combustion cylinder with combustion taking place just as the trailing end of the combustion piston passes the outlet from the pressure passage. In addition to forming the chambers within the cylinders, the valves are driven by the pistons into passageclosing relation with the inlet and outlet for the pressure passage, such inlet and outlet being within the walls of the compression and combustion cylinders, respectively. Movement of such valve into its chamber-forming position takes place as the trailing end of the corresponding piston moves downstream, permitting the valve to be driven out of its passage-closing position and back into its chamber-forming position.

Description

United States Patent [1911 Blaszczynski [111 3,818,886 [4 June 25, 1974 1 ROTARY INTERNAL COMBUSTION ENGINE [76] Inventor: Zdzislaw Blaszczynski, 174

Pleasant View Rd., Thomaston, Conn. 06787 [22] Filedz May 4, 1973 [21] App]. No.: 357,350

Related 0.8. Application Data [63] Continuation'inpart of Set. No. 230,783, March 1,

1972, abandoned.

[52] 11.5. C1. 123/841, 123/825 [51] Int. Cl. F02b 53/08 [58] Field of Search 123/8.l7, 8.23, 8.25, 8.41

[56] References Cited UNITED STATES PATENTS 1,180,747 4/1916 White l23/8.41 1,186,879 6/1916 Brush 1,235,786 8/1917 Fleming... 1,366,919 2/1921 Marvin .1 1,405,326 1/1922 Powell 1,810,082 6/1931 Marvin 1,916,318 7/1933 Huber 2,289,342 7/1942 Canfield.... 2,933,505 5/1960 Quarter 123/825 3,361,119 1/1968 Floxley-Conolly 123/823 2.196.675 4 /1940 Humrichouse 123/841 Primary E.\'aminerC. J. Husar Attorney, Agent, or Firm-Steward & Steward [57] ABSTRACT A rotary-piston internal combustion engine having an annular compression cylinder and a separate annular combustion cylinder with one or :more passages interconnecting the two cylinders and with valves dividing the compression cylinder into intake and compression chambers and the combustion cylinder into combus tion and exhaust chambers. At least one piston is mounted within each cylinder and is rigidly mounted on a drive shaft common to the pistons for both cylinders, such that it revolves within its corresponding cylinder. The piston in thecompression cylinder compresses a charge of gaseous fuel mixture into the passage between the cylinders, from which the gases expand into the combustion cylinder with combustion taking place just as the trailing end of the combustion piston passes the outlet from the pressure passage. In addition to forming the chambers within the cylinders, the valves are driven by the pistons into passageclosing relation with the inlet and outlet for the pressure passage, such inlet and outlet being within the walls of the compression and combustion cylinders, respectively. Movement of such valve into its chamber-forming position takes place as the trailing end of the corresponding piston moves downstream, permitting the valve to be driven out of its passage-closing position and back into its chamber-forming position.

30 Claims, 24 Drawing Figures PATENTED JUN2 5 I974 SHEEF 1 (If 9 PATENTEDJUNZSIHM FIG. 22

FIG. 23

FIG24 SHEET 9 BF 9 I re 1 ROTARY INTERNAL COMBUSTION ENGINE This application is a continuation-in-part of copending application Ser. No. 230,783, tiled Mar. 1, 1972, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to improvements in rotarypiston internal combustion engines, and it relates more particularly to rotaryengines having companion pairs of compression and combustion chambers or cylinders, in which a combustible mixture of fuel is compressed in one cylinder and then fed to the other where it ignites and drives a rotor. Because of their two-cylinder arrangement, rotary engines of this general type are sometimes referred to hereinafter as dual-cylinder engines.

Dual-cylinder engines have been provided with arcuately elongated pistons, the leading end of each of which is located adjacent the trailing end of a companion piston in the other cylinder in staggered relation to each other, so that a compressed charge in one cylinder may be fed directly into a combustion chamber in the other. They have also employed movable partitions for dividing each cylinder into separate chambers disposed circumferentially of each other. As each piston reaches one of the partitions it cams that partition out of way so that the piston rotates uninterruptedly through the annular cylinder. During such rotation each partition is driven by some means, such as a heavy spring, back into its chamber-forming position as each of the pistons travels downstream of it, thereby forming one chamber downstream, between it and the trailing end of the piston, and a second chamber upstream of it.

For example, the compression cylinder may be provided with one or more partitions, each of which forms a suction or intake chamber downstream and a compression chamber upstream. Similarly, the combustion cylinder is provided with a corresponding number of partitions, dividing it into combustion and exhaust chambers. The two cylinders are interconnected by one or more passages into which a combustible air-fuel mixture is driven by the compression piston. Each of such passages discharges into the combustion cylinder downstream of one of the chamber-forming partitions where the fuel is ignited and, as it expands, drives the combustion piston and therefore the rotor. The spent exhaust gases are then discharged through exhaust ports located upstream of each partition in the combustion cylinder.

A disadvantage of such prior dual-cylinder rotary engines is that the combustion and compression chambersare difficult to seal against leakage to the atmosphere, as well as from one chamber to another within the engine. One of the reasons for this is that the transfer of the compressed fuel mixture from the compression cylinder to the combustion cylinder has usually been effected only by means of chamber-forming valves within the cylinders, these valves having the sole function of dividing each of the cylinders into chambers disposed annularly of each cylinder. It has therefore been necessary up to now to provide complicated, externally actuated valving mechanisms, which are not only difficult to maintain, but in some cases act so slowly that they greatly reduce the output of the engine.

An object of the present invention is to provide a simplified design of dual-cylinder, rotary-piston engine,

SUMMARY OF THE INVENTION A rotary engine in which the present invention is employed includes one or more arcuate compression pistons which revolve within a cylindrical compression space, together with a corresponding number of arcuate combustion pistons rigidly mounted on the same rotor with the compression piston, but revolving within a separate cylindrical space in which combustion takes place. Each piston extends lengthwise an equal dis tance in terms of degrees of arc along its path of travel with the compression pistons disposed substantially end-to-end and in staggered relation with the combustion pistons, so that together they extend substantially continuously around the complete circumference of the rotor. One or more pressure passages disposed circumferentially of each other interconnect the compression and combustion cylinders, each passage having an inlet from the compression cylinder for receiving the fuel mixture as it is compressed by the compression piston, and an outlet to the combustion cylinder for discharging the compressed fuel into the combustion cylinder. A compression valve is mounted adjacent the compression cylinder near the inlet to each pressure package, such that it can move into a chamber-forming position within the compression cylinder downstream of the inlet, in order to divide such cylinder into a compression chamber upstream and an intake chamber downstream. A combustion valve is similarly mounted adjacent the combustion cylinder near the outlet for each pressure passage, each combustion valve being movable into a chamber-forming position within the combustion cylinder upstream of the outlet so that this cylinder is in turn divided circumferentially into an exhaust chamber upstream of such valve and a combustion chamber downstream of it.

The invention basically resides in disposing both the compression valve and the combustion valve at each pressure passage so that when each is moved out of its chamber-forming position, it closes the respective inlet or outlet to the pressure passage. Each valve therefore has two functions: one to divide each annular cylinder into separate chambers, the other to close off the pressure passage between the cylinders. Thus, as the leading end of the compression piston moves the compression valve at each pressure passage from its chamberforrning position, the same valve moves into a passageclosing position with the inlet to the pressure passage. Similarly, as the combustion piston moves the combustion valve at each pressure passage from its chamberforming position, the combustion valve also moves to a passage-closing position with the outlet from the same pressure passage. Since the pistons are disposed end-to-end in staggered relation within the two cylinders, the leading end of a piston in one cylinder is located at the opening to each pressure passage when the trailing end of a piston in the other cylinder is adjacent the other opening to the same passage. Consequently, the two valves at each pressure passage are operated in opposite directions and substantially at the same time as the ends of the two co-operating pistons in the two cylinders move into and out of engagement with them.

Thus, as the trailing end of the compression piston passes the inlet to each pressure passage, the compression valve at this location moves from its passage closing position to its chamber-forming position. Simultaneously therewith the leading end of the combustion piston cams the combustion valve at the same location out of its chamber-forming position and into its passage-closing position. The fuel mixture in the compression chamber is therefore compressed by the next compression piston into the pressure passage where it is trapped by the combustion valve. Then, as the leading end of the compression piston moves the compression valve back into its passage-closing position, the trailing end of the combustion piston releases the combustion valve, which is driven instantly into its chamberforming position as ignition of the fuel mixture takes place.

The advantage in this arrangement is that the openings, to and from the pressure passage are positively controlled by the pistons themselves, so that each pressure passage becomes in effect an integral part of the compression chamber during the compression phase of each cycle and, alternatively, an integral part of the combustion chamber during the combustion phase of each cycle. This cooperative interaction of the pistons and valves at each pressure passage, which will be more clearly understood from the detailed disclosure hereinafter, eliminates the need for complicated valveactuating devices, which can breakdown or require maintenance and, which in any event are inherently too slow-acting to prevent leakage. In addition, throughout the entire combustion stroke, the expanding gases urge the seals in the valves into sealing engagement with fixed valve seats, thereby overcoming the problem usually encountered in rotary internal-combustion engines of leakage between continually moving parts.

It will be noted that more than one piston may be provided in each cylinder, as long as there is a corresponding number of pistons in the companion cylinder, and as long as such pistons are disposed at equal intervals within each cylinder. In addition, while each cylinder is ordinarily provided with a plurality of valves equally spaced from each other, the valve arrangement of the present invention is capable of use in rotary engines having only one pressure passage between the cylinders. Such engines thereof employ only one compression valve and one combustion valve. Furthermore, in order to obtain the desired horsepower for a particular power plant, several pairs of compression and combustion cylinders can be provided axially of the drive shaft, so that a number of combustion pistons will be acting on the drive shaft simultaneously.

For purposes of facilitating the disclosure, the first embodiment of the invention disclosed in detail hereinafter is one in which companion compression and combustion cylinders are disposed concentrically of each other, that is, one within the other, rather than axially or side-by-side. Such an arrangement, moreover, has certain advantages that can not be achieved in any other way. However, it is believed that for most applications the cylinders should be disposed side-by-side, axially of the drive shaft as described in detail hereinafter in connection with another form of the invention considered at the present invention to provide advantages from a design standpoint, as well as in facilitating the manufacture and production of the engine.

DESCRIPTION OF PREFERRED EMBODIMENTS These and other objects and advantages of the invention will be more apparent from the detailed description of certain preferred embodiments and of modifications shown or suggested by the accompanying drawings wherein:

FIG. I is a front view of a power plant incorporating one embodiment of the invention;

FIG. 2 is a longitudinal sectional view of the power plant shown in FIG. 1, but on a larger scale and taken on the line 2-2 of FIGS. 1 and 3, looking in the direction of the arrows, and rotated clockwise through 90;

FIG. is a vertical cross-section of the same shown on an intermediate scale and taken on line 3-3 of FIG. 2 looking in the direction of the arrows, portions of the annular pistons being broken away in order to expose parts behind them FIG. 4 is a detailed sectional view taken on the line 44 of FIGS. 1 and 3 but on a larger scale;

FIGS. 5 and 6 are enlarged detail views in vertical cross-section through one set of compression and combustion valves at one of the pressure passages and showing the actuation of the valves at substantially opposite ends of companion pistons;

FIG. 7 is a plan view on an enlarged scale of one of the compression valves;

FIG. 8 is a detail view in cross-section of the outer edge portion of the valve shown in FIG. 7 on a still larger scale, taken on line 8-8 thereof, and showing portions of the cylinder and piston, with which it cooperates;

FIG. 9 is another detail of one of the side edge portions of the valve shown in FIG. 7 and taken in crosssection on the line 9-9;

FIG. 10 is a front view of the compression piston and piston-wheel shown on the same scale as in FIG. 3;

FIG. II is an enlarged detail view in cross-section of the compression piston taken on the line l1l1 of FIG. 10;

FIG. 12 is a partial view on an enlarged scale of the trailing end portion of the combustion piston-wheel;

FIG. 13 is a view similar to FIG. 12 of the leading end of the combustion piston;

FIG. 14 is a cross-sectional view of the combustion piston taken on the line l4l4 of FIG. 12;

FIG. 15 is a view similar to FIG. 14 ofa slightly differ- I ent form of combustion piston and showing another manner of mounting it on its mounting ring;

FIG. 16 is a more or less diagrammatic view of a second embodiment of the invention shown in longitudinal section through the center of the power plant;

FIG. I7 is a vertical cross-section taken on the line I7l7 of FIG. 16;

FIG. 18 is a detailed sectional view on the line ll8l8 through the valve assemblage shown in FIG. 17;

FIG. 19 is a sectional view taken on the line 19--l9 of FIG. 18;

FIG. 20 is a pictorial representation of the valve and piston portion of the power plant shown in FIGS. 16-19 with the outer housing and one of the pistons removed in order to expose other parts and with portions thereof shown broken away and in section;

FIG. 21 is a view similar to FIG. 19, but showing the positions of the pistons after the rotor has moved through one-half a revolution; and

FIGS. 22, 23 and 24 are diagrammatic views of still another valve and piston arrangement embodying the invention, showing in sequence how the leading and trailing ends of the pistons co-operate to control the operation of the valves in accordance with the invention.

CONCENTRIC CYLINDER ARRANGEMENT OF FIGS. ll-6 Referring more particularly to FIGS. 13, a cylindrical housing 10 encloses a power plant having two sets of companion compression/combustion cylinders, indicated generally in FIG. 2 as sections A and B, each section being identical and consisting of a concentric, annular inner cylinder 12 and outer cylinder 14. Cylinders l2 and 14, are formed within a separate cylinder casing 16 for each of sections A and B. Cylinder casings 16, 16 are ring-shaped and are rigidly mounted at their outer cylindrical surfaces to the housing 10 at both ends thereof. Spacer rings 17, 17 through which bolts 18 extend, are positioned at opposite ends of the power plant between casings, 16, 16 and housing 10 in order to provide an annular space 19 within the housing outward of cylinder casings 16, 16, for a reason which will be more apparent hereinafter.

A drive shaft 20 is rotatably supported at each end axially within housing 10 on main bearings 22, 22, which are mounted centrally within circular openings 23, 23 in casings 16, 16 adjacent the outer end-walls thereof. Each pair of concentric, annular cylinders 12 and 14 comprises companion compression and combustion cylinders. In this particular case, the inner cylinder 12 of each pair is the compression cylinder, and the outer cylinder 14 is the combustion cylinder, but it will be appreciated that the reverse may be desirable in certain instances.

A rotor assembly indicated generally at 24 (FIG. 2) is mounted rigidly on, and keyed to, drive shaft 20 by means of a key 25 for rotation therewith. Rotor 24 consists of two piston- wheels 26, 26 mounted at their centers in spaced, parallel relation to each other on shaft 20 and concentric therewith, each piston-wheel 26 extending outward through a radially disposed, annular slot 27 in its respective cylinder casing 16 into the corresponding one of its compression cylinders 12, 12. As will be more apparent hereinafter, each slot 27 is formed in the inner cylindrical wall of one of the ringshaped casings 16, 16 and provides access to the corresponding annular cylinder 12. As best viewed in FIGS. 2 and 10, an arcuately elongated compression piston 28 is rigidly mounted at the periphery of each pistonwheel 26, 26. Pistons 28, 28 have the same radius as the compression cylinders 12, 12 within which each rotates, and each of pistons 28, 28 has a cross-sectional shape that is the mirror image in cross-section of its cylinder 12 but slightly smaller all around. Each of pistons 28 is positioned radially on its piston-wheel 26 at a fixed distance from the axis of rotation equal to its radius of curvature, so that it completely clears the walls of the cylinder. The length of each piston 28, 28 at its outermost diameter is desirably equal to one-half the circumference of its cylinder 12,

Interposed between the two piston- wheels 26, 26, as a unitary part of rotor 24, is a central wheel-like memher 30, that is common to both sections A and B of the engine. Wheel-member 30 is provided with a hub 32, by which it is mounted on shaft 20 and to the opposite ends of which are bolted piston- wheels 26, 26. The circular periphery of wheel-member 30 projects radially outward of cylinder casings 16, 161 and is bolted inside a cylindrical drum or cross-head 341 midway between its edges 35, 35. Drum 34, which surrounds portions of cylinder casings 16, I6, is disposed concentrically of the housing 10 within the annular space 19 between the inner surface of the engine housing and the outer surfaces of cylinder casings 16, 16. A series of recessed bolts 37 (FIG. 4) spaced circumferentially around wheel-member 30 rigidly fasten it to the inner surface of drum 34.

A pair of ring-shaped piston-wheels 38, 38 (FIGS. 2, 4, 12 and 13) are bolted to the inner surface of crosshead drum 34 adjacent its edges 35, 35, so that each piston-wheel 38 extends into its corresponding combustion cylinder 14 through a radially disposed annular slot 40 in the periphery of each cylinder casing 16. Slot 40 is disposed completely around the circumference of each casing 16 and provides access: for piston-wheel 38 to annular combustion cylinder 14. At the inner edge of each piston-wheel 38 within its combustion cylinder 14 is mounted an arcuately shaped, or torus-like, combustion piston 42, having a cross-sectional shape which is the mirror image of, but slightly smaller than, that of its cylinder 14 for rotation therein about the longitudinal axis of drive shaft 20. The length of each combustion piston 42 is desirably such that its innermost surface is exactly semi-cylindrical.

As illustrated in FIGS. 14 and 15 combustion pistons 42, 42 may have various cross-sectional shapes and may be mounted on piston-wheels 38 in any suitable manner, the same being true of compression pistons 28. FIGS. 10-14 show a shape and construction for both the compression and combustion pistons which is similar to that of each of the pistons hereinbefore referred to in connection with FIGS. I-6 in that the crosssectional profile of each piston is semi-circular at the ends and has a laterally elongated central portion. In the case of piston 28 (FIGS. 10 and 11), a pair of arcuately elongated sections 41, 41 are mounted, one on each side of piston-wheel 26 by means of a row of bolts 43, each of which extends transversely through both sections 41, 41 and through a peripheral segment 26.] on the circumference of annular piston-wheel 26. Both ends of each bolt 43 are recessed within the sections 41, 41, so that they lie below the surfaces of the piston 28. Similarly, the combustion piston 42, portions of which are shown on an enlarged scale in FIGS. 12-14, has arcuate sections 41a mounted on opposite sides of the annular piston-wheel 38 to a segment 38.1 on the inner edge thereof.

The segments 26.1 and 38.1 of piston- wheels 26 and 38, respectively, extend circumferentially the same distances around their respective piston- wheels 26 and 38 as the piston-forming sections 41, 41a and are shaped the same as said sections at both ends. In addition, in order to provide greater support for piston sections 41, 41a, segments 26.1 and 38.1 are somewhat reduced in width in order to form arcuate shoulders 26.2 and 38.2, respectively, on both sides of pistonwheels 26 and 38 against which sections 41, 410 are rigidly held. As illustrated in FIGS. 10, 12 and 13, the holes 43a in pistonwheels 26 and 38, through which mounting bolts 43 extend, may be arcuately elongated, so that the piston sections 41, 41a can be adjusted lengthwise. Such adjustment makes it possible to shift the position of the piston-forming sections so that their ends are exactly flush with the corresponding ends of the mounting segments 26.1 and 38.1 on piston- wheels 26 and 38, thereby providing broad surfaces at the ends of the pistons 28 and 42 for camming engagement with the chamber-forming valves in each cylinder as will be more apparent hereinafter.

In another form of piston shown in FIG. IS, the two lateral sections 41 41 of piston 42' are shown welded to the piston-wheel instead of bolted as in FIGS. 10-14. Furthermore, as illustrated only by way of example, the cross-sectional shapes of the pistons may differ. However, the cross-sectional shape of compression pistons 28, 28 for each engine is desirably the same as that for its combustion pistons 42, 42.

The maximum width P (FIGS. 14 and 15) of combustion piston 42 should be substantially greater than the width W of the piston-wheel 38 on which it is mounted. Thus, since only the narrow width W of piston-wheel 38 is exposed to the pressures developed within the combustion cylinder 14, the total force exerted in a radial direction on rotor 24 is relatively small. Consequently, problems of counteracting or balancing the forces on rotor 24 in order to reduce vibration, bearing wear and friction are not as critical as in rotary internal combustion engines of most prior designs. Furthermore, and of even greater importance, the provision of annual rotary pistons ensures that most of the force resulting from combustion of the fuel is exerted tangentially of the rotor at a fixed distance from the center of rotation, thereby producing maximum torque on shaft and contributing substantially to improvement in the efficiency of this type of rotary engine as compared to other types of rotary engines, as well as to reciprocating piston engines.

As best seen in the cross-sectional view of FIG. 3 through the section A of the engine, the arcuate compression piston 28 and arcuate combustion pistion 42 are disposed diametrically opposite each other on rotor 24, so that their ends overlap. A pairof pressure passages 44 and 440 are also provided diametrically opposite each other in the annular wall 47 in cylinder casing 16 between cylinders 12 and 14. Each of pressure passages 44, 44a is identical and is provided with a relatively small inlet 46 (FIGS. 5 and 6) from the compression cylinder 12 and an enlarged outlet 48 to the combustion cylinder 14.

VALVE ARRANGEMENT OF EMBODIMENT SHOWN IN FIGS. 1-15 Pivotally mounted downstream. i.e. in the direction of rotation illustrated by arrows R, of each inlet 46 within compression cylinder 12 is a compression valve 50, 500, the free end 52 of which extends upstream for pivotal movement between a chamber-forming position (FIG. 6) and a passageclosing position (FIG. 5). With piston 28 in the position shown in FIG. 3, compression valve 50 is disposed across cylinder 12 in its chamberforming position, its free end 52 extending upstream of its pivot shaft 54, by which it is pivotally mounted in the cylinder casing 16. At the same time valve 50a diametrically opposite is held by piston 28 in its passage-closing position.

As may be seen in FIG. 7, compression valve 50 is a rectangular member, the dimensions of which are greater than the corresponding cross-sectional dimensions of cylinder 12 (shown in phantom in FIG. 7), so that the marginal portions thereof rest on a rectangular valve-seat 56 (FIGS. 5 and 6) completely surrounding, and obliquely disposed across cylinder 12, thereby forming within cylinder 12 a compression chamber 58 upstream of valve 50 and an intake chamber 60 downstream thereof. Valve 50a (FIG. 3), on the other hand, is shown in its passage-closing position, in which it is completely retracted out of the path of piston 28 within a rectangular recess 62 (FIG. 6) in the walls of cylinder 12 adjacent thereto. In their passage-closing positions, valves 50, 50a seat against rectangular valve-seats 64 surrounding the openings 46 to the pressure passages 44, 440. As best shown in FIG. 5, flat pie-shaped side walls 65 are formed parallel to each other on opposite sides of cylinder 12 for sealing engagement with the sides of valves 50, 50a as they swing from one position to the other.

Adjacent to, and upstream of, each combustion outlet 48, 48a from pressure passages 44, 44a to the combustion cylinder 14 is pivoted a combustion valve 68, 68a, which is secured to a pin 66, 66a pivotally mounted in cylinder casing 16 for movement between a chamber-forming position across the combustion cylinder 14 and a passage-closing position longitudinally thereof. Like compression valves 50, 50a, each combustion valve 68, 68a is rectangularly shaped and seats against a rectangular valve-seat 70 in its chamberforming position, where it is driven out of the path of piston 42 into a rectangular recess 72, 72a surrounding one of the enlarged outlets from pressure passages 44, 44a, respectively. Each of recesses 72, 72a is provided with a valve-seat 74 surrounding the outlet with which each combustion valve 68, 68a seats when in its passageclosing position. Flat pie-shaped side walls 75 (FIG. 5) are formed in cylinder 14 adjacent each valve 68, 68a for sealing engagement with the sides thereof as it swings between its two positions. In the portion of cylinder 14 shown in FIG. 3 that is momentarily not occupied by combustion piston 42, valve 68a is free to swing into its chamber-forming position where it separates the cylinder 14 into a combustion chamber 76 downstream and an exhaust chamber 78 upstream.

In order to prevent the compressed gases in compression chamber 58 of cylinder 12 from leaking past valves 50, 50a, and causing loss of compression, each of valves 50, 50a is provided with resilient edge seals along its outer end and side edges, as shown for the valve 50 in FIGS. 7-9. Thus, an elongated groove 50.1 is formed adjacent the outer end 52 of valve 50, the inner edge 50.2 of valve 50 being rounded in order to facilitate lifting of valve 50 from its chamber-forming position by the leading edge of piston 28. Groove 50.1 is rectangularly shaped in cross-section and extends across the full width of the valve so that it opens at both side edges 50.3, 50.3 of the valve, thereby permitting removal and replacement of a sealing strip 50.4 through the open ends of the groove.

The outer longitudinal edge of sealing strip 50.4 projects outward of groove 50.1 through a restricted opening in the edge 50.2, the inner portion of strip 50.4 being enlarged so that it cannot escape edgewise from groove 50.1. Groove 50.1 is deep enough to permit limited edgewise movement of sealing strip 50.4 through the restricted opening of the groove. A series of holes 50.5 are provided along the length of groove 50.1, each hole extending from groove 50.1 above the sealing strip 50.4 to the pressure side of valve 50. Thus, when valve 50 or 500 is in its chamber-forming position, as illustrated diagrammatically in FIG. 8, pressure in compression chamber 58 is exerted on the inner side of sealing strip 50.4, forcing it outwardly against the valve-seat 56 in the wall of cylinder 12. Likewise, seal 50.4 maintains sealing engagement with the inclined end 79 of compression piston 28 as the latter cams each compression valve out of engagement with valve-seat 56, thereby ensuring a tight seal at all times between the compression chamber 58 and intake chamber 60.

Grooves 50.6 and sealing strips 50.7, similar to the grooves 50.1 and 50.4, are provided in both side edges 50.3 of valve 50 for sealing the sides of the valve with the side walls 65 of the cylinder. In this case, however, the seal is disposed perpendicular to the edge of the valve instead of obliquely. Pressure holes 50.8 are provided to grooves 50.6 from the pressure side of valve 50 so that the seals press more tightly into engagement with the valve-seat as the pressure within the compression chamber increases.

In order to reduce friction while maintaining an adequate seal between valve 50 and piston 28, an antifriction roller 51 is mounted on valve 50 on the side that is adjacent to piston 28. Roller 51 is located centrally of cylinder 12 near the outer end of the valve 50 within a recess in the surface of the valve, so that it projects outward therefrom for engagement with the leading end 79' of piston 28 while permitting seal 50.4 to remain in sealing engagement with the piston until valve 50 reaches is passage-closing position. Roller 51 then remains in contact with the narrow segment 26.1 of piston-wheel 26, thereby reudcin drag.

Combustion valves 68, 68a are provided with seals similar to those for valves 50, 50a and with rollers 51 for reducing friction and drag on combustion pistonwheel 38. Since the pressure in combustion chamber 76 is relatively low at the time piston 42 starts to engage either of valves 68, 68a, the resistance of valves 68, 68a to movement out of their chamber-forming positions is not as great as that involved in moving the compression valves 50, 50a to their passage-closing positions. However, rollers 51 help reduce friction between valves 68, 68a and piston 42 caused by the pressure in pressure passages 44, 44a during the compression stroke. Moreover, seals should be provided along the lateral edges of valves 68, 68a for sealing engagement with the side walls 75 (FIG. of the valve chamher, as well as along its outer edge, in order to prevent blowby both during the instant that each of the valves pivots into and out of its chamber-forming position and while it is in engagement with its valve-seat 70 during the combustion stroke.

It is also desirable to provide seals in the valveseats 64 and 70 at the inlet and outlet, respectively, of each pressure passage 44. Seals 64.1 (FIGS. 5 and 6) may therefore be provided in grooves in the wall 47 of the cylinder casing around the inlet 46, and seals 70.1 around the outlet 48, for engagement by vlaves 50 and 68, respectively, when in their passage-closing positions. Seals 64.1 and 70.1 are similar in design to the seals 50.4 on the compression and combustion valves, each having pressure holes extending from the groove behind the inner edge of the sealing strip to the pressure chamber 44 so that the pressure within chamber 44 forces the seals outward against the valve.

An important advantage of the present invention resides in the fact that it is not as difficult to seal one chamber form the other as in prior rotary engines because friction and wear due to movement of the rotor against the seals can be greatly reduced. In the first place, if any seals at all are required between the pis' tons and the walls of the cylinders within which they revolve, they are not subjected to the pressure in the cylinder, because the pistons never actually engage the walls of the cylinders. Furthermore, the great length of the pistons themselves will in most. cases make sealing of the pistons with the cylinders unnecessary.

The only other points at which seals must be made with moving parts are where the piston- wheels 26 and 38 extend into the cylinders and where the valves 50 and 68 must seal with the ends of the pistons during the short periods when they are moved by the pistons to and from their passage-closing positions. As illustrated in FIG. 8, the seals 50.4 at the outer ends of the valves engage the moving piston-wheels only along the relatively narrow circumferential edges: of the pistonwheels and along the inclined ends of the pistons. Once each valve is in its passage-closing position it is held by the piston against a stationary valve-seat, and no seal is required between the moving piston and the valve.

In order to reduce wear of the seals as much as possible, it is desirable to prevent the full force of the pressure on the valves in the compression and combustion chambers from being exerted on seals 50.4 while they are in contact with the piston-wheels. To this end, the circular portion 26.4 on the periphery of piston-wheel 26 which is opposite its piston 28 is formed with a diameter that is somewhat less than that for the cylinder 12 at its inner diameter, so that this portion of the periphery of the piston-wheel is recessed slightly inward of cylinder 12, as illustrated in section A of the engine shown in FIG. 4. In the case of the piston-wheel 38, the corresponding edge portion 38.4 has a slightly greater diameter that the OD. of cylinder 14 so that it is recessed outwardly thereof, as shown in section B of the engine. When valves 50 and 68 are seated against their chamber-forming valve- seats 56 and 70, respectively, only their seals 50.4 (FIG. 8) touch the moving edges 26.4 and 38.4 of the corresponding piston-wheel. Consequently, all the pressure on each valve is exerted against the fixed valve-seat in the wall of the piston, rather than on the revolving piston-wheel. Seals 50.4 nevertheless are forced into engagement with the piston-wheels by the pressure exerted on them by the gases through pressure holes 50.5 in the opposite sides of the valves as described hereinbefore, thereby providing the necessary seal with the edge of the pistonwheel.

Cylinders l2 and 14 are also provided with intake and exhaust ports by which a combustible fuel mixture is drawn into the intake chamber 60 behind compression piston 28 and the exhaust gases are swept from the exhaust chamber 78 in front of combustion piston 42. To this end, compression cylinder 12 has a pair of intake ports 80, 800, each located immediately downstream of its corresponding compression valve 50, 50a, so that as the trailing end of piston 28 passes each valve 50, 50a, permitting it to move into its chamberforming position, a gaseous fuel is drawn into the intake chamber' 60 from a suitable source, such as a carburetor (not shown). Similarly, combustion cylinder I4 is provided with a pair of exhaust ports 82, 82a, each located immediately upstream of its corresponding combustion valve 68, 680, so that as the trailing end of combustion piston 42 passes each valve 68, 68a, pen'nitting it to move into its chamberforming position, the gases of combustion are swept out of the exhaust chamber ahead of piston 42.

Referring in greater detail to the construction of cylinder casings l6, 16 as shown more particularly in FIGS. 2 and 4, it will be seen that casing E6 of the section A of the engine is the same as the corresponding casing in section B except that it faces in the opposite direction. Each casing I6 is made up of two annular halves 84 and 86, which mate face to face along a parting line 88 (FIG. 4) through the annular wall 47 that separates cylinders I2 and 14 and is common therewith. The mating surfaces along parting line 88 are desirably stepped as shown in FIG. 4 in order to ensure accurate alignment of the two halves 84 and 86, which are bolted together by means of a ring of bolts 90 extending through wall 47.

Cylinders l2 and I4 are formed partly in one half 84 and partly in the other half 86 of easing I6. In addition, the inner slot 27 and outer slot 40, through which piston-wheel 26 and annular piston-wheel 38, respectively, extend radially into their corresponding cylinders l2 and 14, are formed by radially inner and outer surfaces 92 and 94 on the half 84 and by radially inner and outer surfaces 96 and 98 on the other half 86 which faces in the opposite direction. Both the facing surfaces 92 and 96 and the facing surfaces 94 and 98 are precisely spaced from each other when the two halves 84 and 86 are bolted together in order to provide close clearance tolerances on both sides of piston- wheels 26 and 38. Suitable packing rings I and I02 (FIG. 4) are provided in annular grooves in facing surfaces 92 and 96, respectively, on opposite sides of piston-wheel 26 in order to seal cylinder 12. Similar packing rings I04 and 106 are provided on opposite sides of pistonwheel 38 for sealing cylinder 14.

During each revolution of rotor 24, pistons 28 and 42 pivot their respective valves 50, 50a and 68, 68a from the chamber-forming positions into the passage-closing positions and, therefore, are provided at their leading ends with inclined surfaces which engage the valves and more them positively into the recesses 62 and 72, respectively, where they are completely out of the path of their respective pistons and are held in sealing engagement with the passage-closing valve-seat by the pistons themselves. In order to facilitate movement of the compression valves 50, 50a into their passageclosing positions, the leading end 79 of compression piston 28 is gradually inclined inwardly toward its tip 108. Counterclockwise rotation of piston 28 as viewed in FIG. 3 causes its leading end 79 to move successively into engagement with the rounded edge 50.2 (FIG. 8) at the free end 52 of each compression valve 50, 50a and to lift it outward to its passage-closing position. It should be noted, however, that before the inclined portion of piston 28 actually engages valve 50, the outer end 52 of the valve is engaged from below (see FIG. 8) by the sloping portion of the edge of piston-wheel 26 where its reduced-diameter section 26.4 merges with the piston-mounting segment 261. Movement of valve 50 out of engagement with its valve-seat 56 is facilitated in this manner.

Similarly, the leading end of combustion piston 42 is gradually inclined with respect to the path of the piston, but in this instance surface 110 is inclined outwardly towards its tip 112, so that the combustion piston engages the free end 113, 113a (FIGS. 5 and 6) of each combustion valve 68, 68a only at the extreme end of each exhaust stroke. Each of valves 68, 68a is thus moved consecutively by combustion piston 42 into its passage-closing position at the beginning of each combustion stroke. v

In order to still further reduce friction and wear between the valves 50 and 68 and the surfaces of pistons 28 and 42, respectively, it is desirable to extend the periphery of their respective piston-mounting segments 26.1 and 38.] (FIGS. 11 and 14) slightly beyond the surfaces of the pistons, thereby forming circumferential ribs 26.3 and 38.3, respectively. A mating groove 114 (FIG. 4) in the outer wall of cylinder 12 receives the rib 26.3 on piston 28, while a similar groove 115 in the inner wall of cylinder 14 receives rib 38.3 on piston 42.

As best seen in FIG. 5, when valves 50 and 68 are in their passage-closing positions, their anti-friction rollers 51 ride on the respective ribs 26.3 and 38.3 of pistons 28 and 42. Due to the fact that the ribs 26.3 and 38.3 are narrow, friction is virtually eliminated. Furthermore, these ribs may be hardened for longer wear. In the drawings ribs 26.3 and 38.3 are shown greatly exaggerated in height, it only being necessary to lift the rollers 51 of valves 50 and 68 a slight distance off the surface of the pistons 28 and 42, respectively.

It is desirable for ignition of the compressed charge to take place within each pressure chamber 44, 44a immediately after each compression valve 50, 50a is completely closed. Consequently, both the pressure due to compression and the pressure of combustion are exerted against the corresponding combustion valve 68 or 68a, forcing it out to its chamber-forming position across cylinder 14. The pressure of the burning fuel will of course be immediately exerted on the trailing end 116 of combustion piston 42 as it moves beyond the free end 113, 113a of each of the combustion valves. In order to ensure almost instantaneous movement of combustion valves 68, 68a to their chamber-forming positions, and at the same time, to reduce energy losses by ensuring that the gases of combustion exert as much pressure as possible tangentially of rotor 24, the trailing end 116 of combustion piston 42, unlike its leading end 110, is formed almost square with respect to the direction of piston travel. However, in order to prevent damage to combustion valves 68, 68a and to reduce noise as they are driven into their chamber-forming positions, it is desirable to provide the end-surface 116 with a short incline at the outermost side of piston 42, so that the valves are, comparatively speaking, gradually let off the piston on to the valve-seats 70.

In addition, a shock-absorber or cushioning device 118 (shown more or less diagrammatically in FIG. 1) may be mounted on the pivot shaft 66 or 66a of each combustion valve 68, 68a externally of cylinder casings l6, 16 for cushioning their impact against the valveseats 70 as they are released by the piston 42. For example, each shockabsorber 118 may consist of a lever 120 fixed to one end of pivot shaft 66, which projects outward of casing 16. A dash-port 122 having a plunger 124 is mounted on the casing for engagement by the outer end of lever 120 such that clockwise movement of lever 120, as viewed in FIG. I, forces plunger 124 inward. Valves 68, 68a are accordingly prevented from engaging their chamber-forming valve-seats 70 with too great an impact, yet are provided freedom of movement in bothdirections at all other times. Where space within the cylinder casing permits, internal cushioning devices may be employed in place of the external shock-absorbers 118. Such an internal device could be mounted, for example, in the valveseats 70 in the walls of each combustion cylinder for direct engagement by valves 68 or 68a.

While the displacement of cylinder 12 in comparison with the volume of pressure passage 44 may e designed to provide a compression ratio that is high enough to ignite diesel fuel due to the heat of compression, the engine here illustrated is assumed to be a gasoline engine and is therefore provided with two spark plugs 126 and 126a for each combustion cylinder. Each spark plug 126, 11260 is threaded through a suitable opening in the outer wall of cylindercasing 16 into each of the pressure passages 44, 44a, and an ignition distributor (not shown) with leads to each spark plug times the ignition of the compressed fuel just before or after each combustion valve 68, 68a moves to its chamberforming position.

An important feature of the present invention resides in the capability of both compression and combustion valves at both pressure passages 44, 44a, to function almost simultaneously on completion of each compression stroke of piston 28 and on ignition of the compressed charge in the pressure passage, without the provision of any external valve-actuating mechanism. Thus, in the present embodiment of the invention as clearly illustrated in the enlarged detail view of valves 50 and 68 shown in FIG. at the instant that compression is complete, the inclined surface 79 at the leading end of compression piston 28 has cammed the compression valve 50 upward into its passage-closing position, in which it seals the inlet 46 to pressure passage 44. The trailing end H6 of combustion piston 42, on the other hand, is on the point of releasing combustion valve 68, which is still in sealing engagement with the outlet 48 to cylinder M from the pressure passage 44 and is under pressure from the compressed fuel therein. The opposite side of valve 68 is exposed to the exhaust port 82 in cylinder I4 and is therefore under relatively light pressure.

Ignition by means of spark plug 126 is desirably timed to take place at the instant shown in FIG. 5 just before combustion valve 68 is released by piston 42, so that on release, it is driven by the expanding gases of combustion within passage 44 almost instantaneously into its chamberforming position against valve seat 70. Combustion then continues and the expanding gases drive piston 42 through another one-half revolution where the same interaction between valves 50a and 68a takes place to initiate another power stroke during the next half revolution. The companion cylinders and pistons in section B of the engine are at the same time operating in the same manner as those of section A but 180 out of phase therewith, so that as one power stroke in section A is being completed another in section B is starting, thereby not only maintaining power throughout each revolution, but also balancing the forces exerted on the rotor.

Any desired ratio of the volumes of the compression cylinder to the combustion cylinder can be obtained by proper selection of the cross-sectional dimensions and lengths of the pistons. Likewise, the distance required for valves 50, 50a and 68, 68a to move between their passage-closing position and chamber-forming position can be reduced by decreasing the cross-sectional dimension H (FIG. I4) of the pistons and cylinders in a radial direction, while increasing their width P in order to obtain the desired displacement. This is especially important in connection with the combustion cylinder 14 and valves 68, 68a in order to prevent loss of cylinder pressure due to possible blowby past the combustion valve before it seals with its chamber-forming seat 70.

FIG. 6 is a view showing the condition of valves 50 and 68 after one-half of a revolution of pistons 28 and 42 from the position in which they are shown in FIG. 5. Piston 42 completes each exhaust stroke as its leading end engages valve 68 camming it into passageclosing position and sealing the outlet 48 from passage 44. Shortly after outlet 48 is sealed off by valve 68, compression valve 50 pivots toward its chamberforming position, in which it is shown in FIG. 6, as the trailing end I28 of piston 28 moves past, thereby opening the inlet 46 to passage 44. At this point a pressure differential exists on opposite sides of valve 50 due to residual pressure in passage 44 from the just completed power stroke and the partial vacuum in cylinder 12 from the intake stroke. The compression valve therefore follows the inclined end surface 128 of piston 28 into its chamber-forming position. If desired, a simple extension spring (not shown) or other suitable means for urging valve 50 toward its chamber-forming position may be provided. However, where such spring means is provided, the force required to overcome it should be light, so that the resistance of the compression valve to movement in the opposite direction by piston 28 to its passage-closing position is not substantially increased.

From the foregoing it will be apparent that each compression valve forms a fixed wall of the combustion chamber when such valve is held in its passage-closing position by the compression piston. On the other hand, when the compression valve is in its chamber-forming position it forms a wall of the compression chamber with the pressure in the compression chamber forcing the compression valve into sealing engagement with its chamber-forming valve-seat. Similarly, each of the combustion valves in its passage-closing position forms another wall of the compression chamber, and in its chamber-forming position forms a wall of the combustion chamber. Each set of valves, therefore function alternately to form a compression chamber and then a combustion chamber, their action being synchronized entirely by, and dependent upon, the rotary movement of the two pistons in companion compression and combustion cylinders. No independent means, such as a cam-shaft, is necessary in order to synchronize the operation of the valves.

' Still another advantage of the present invention resides in its simplicity of design and accessibility of its parts for repair or replacement purposes. For example, each of the compression passages 44, 44a and valve assemblies therefor may be made as a complete subassembly which can be installed and removed from the engine as a unit. Thus, as indicated generally in FIGS. 5 and 6, the pressure-passage 44 may be formed within a section 47a of the annular wall 47 common to cylininders l2 and 14 or to the outside of casing 16.

It will be appreciated that two complete cycles of operations take place during each revolution of rotor 24 for each pair of companion cylinders 12 and 14. In other words, during each revolution two power strokes that extend over l80 of rotation each are provided in each section A and B of the engine here illustrated. Consequently, this power plant produces four power strokes per revolution. In comparison, a four-cycle reciprocating engine must have eight cylinders to produce four power strokes for each revolution. The rotary engine of the present invention accordingly has the advantages of both a four-cycle engine and a two-cycle engine without the disadvantages of either.

Furthermore, at any time during each revolution, except at the instant when each combustion valve 68, 68a shifts into its chamber-forming position, all four phases required in a four-cycle engine are taking place simultaneously. Thus, at the instant of operation shown in FIG. 3, while compression piston 28 is drawing a gaseous fuel-mixture into intake chamber 60 behind its trailing end 128, it is also compressing the previous intake charge in the compression chamber 58 into the adjacent pressure passage 44. During this phase of the cycle compression valve 50 is disposed in its chamberforming position while combustion valve 68 is held in its passage-closing position by combustion piston 42. At the same time, combustion is taking place downstream of combustion valve 68a in combustion chamber 76, which is closed off through pressure passage 44a by compression valve 50a, which in turn is held by piston 28 in its passage-closing position. Simultaneously therewith, the exhaust gases from the previous combustion stroke are swept from exhaust chamber 78 through exhaust outlet 82.

A novel feature of the present design, which can be employed to great advantage for the purpose of obtaining complete combustion of the fuel-mixture during the combustion phase of the Otto cycle is the provision of one or more injection ports 130 (FIGS. 1 and 3) in each half of the combustion cylinder 14 intermediate valves 68 and 68a. Injection ports 130, 130 make it possible to introduce oxygen or other chemicals and catalysts into the combustion chamber 76 under pressure by suitable means (not shown), in order to ensure continued and regenerated combustion of the partially burned gases throughout the power stroke. In this instance, each port 130 is desirably located closer to the downstream one of valves 68, 680 than to the one upstream, so that as combustion begins to dissapate during a later portion of each combustion stroke, renewed combustion can be obtained by injection of a required component of combustion, in order to completely burn the available fuel as the trailing end 116 of the combustion piston moves beyond each injection port 130. Not only does this reduce harmful exhaust emissions, but also it increases the power generated by the engine. It will be appreciated, however, that other injection ports can be provided in any desired sequence at various points along the combustion chamber and that the order in which additions are made during each combustion stroke can be controlled by suitable external equipment (not shown).

SlDE-BY-SIDE CYLINDER ARRANGEMENT OF FIGS. 16-21 In the embodiment of the invention shown diagrammatically, as well as pictorially, in FIGS. 16-21, the compression cylinder 212 and combustion cylinder 214 are the same diameter radially of the drive shaft 220 and are disposed side-by-side axially thereof. The cylinder block or casing 210 for cylinders 212 and 214 may be constructed in various ways to facilitate manufacture and assembly, the details of which are omitted for purposes of clarity. Casing 210, like that in the form of the invention illustrated in FIGS. 1-6, is cylindrically shaped and has an enlarged central opening 223, in which is journaled a hub 232 of a cylindrical rotor assembly 224.

Rotor assembly 224 consists of the shaft 220, a pair of circular piston- wheels 226, 226, each fixed rigidly a shaft 220 on opposite sides of hub 232, an arcuate compression piston 228 within cylinder 212 and a combustion piston 242 within cylinder 214. Pistons 228 and 242 are rigidly mounted at the axially inner edges of a pair of cylindrically shaped, piston-mounting rings 229 and 231, respectively, which extend inwardly toward each other from piston- wheels 226, 226 through annular slots 227 and 240, respectively, in the opposite end walls of the cylinder block 210. Seals 200 are provided on the inner and outer walls of annular slots 227 and 240 in the block 210 in order to prevent leakage around piston mounting rings 227 and 231.

Pistons 228 and 242 may be constructed and assembled on mounting rings 229 and 231 in a manner similar to their counterparts shown in FIGS. 11-15 of the previously described embodiment of the invention, except that the long axis of each piston is disposed radially of the axis of rotation instead of parallel to it. Mounting rings 229 and 231 also are formed so that their inner edges extend beyond the pistons into annular grooves 213 and 215, respectively, within the re spective cylinders 212 and 214. As in the embodiment of FIGS. 1-6, pistons 228 and 242 are disposed endfor-end in staggered relation to each other at diametrically opposite portions of their respective cylinders, each piston occupying substantially half the length of its annular cylinder.

While independent compression and chamber valves similar to those employed in the embodiment of FIGS. l-6 may be used in the side-by-side arrangement of the dual-cylinder power plant illustrated in FIGS. 16-21, it has been found that transfer of the compressed fuel mixture from the compression cylinder to the combustion cylinder may be facilitated in certain instances by providing a unitary valve assemblage in place of the independent valves and 68, hereinbefore described for controlling the flow of the fuel between the two cylinders. Thus, as illustrated in FIGS. 17-21 a pair of sliding valve- assemblies 245, 245a are disposed diametrically opposite each other within the housing 210 each extending radially across the full depth of the annular cylinders 212 and 214. Each of the identical valve assemblies 245 or 245a is a rigid rectangular sleeve guided within a rectangular passage 243, 243a in cylinder block 210 for reciprocal movement across the two annular cylinders, i.e., parallel to shaft 220.

Each of the sliding valve assemblies 245, 245a includes two parallel side members which extend radially of, as well as obliquely to, cylinders 212, 214, such side members forming a pair of vane- type valves 250 and 268 corresponding to the pivoted valves 50 and 68 of the engine disclosed hereinbefore. Valves 250 and 268 are held in fixed relation to each other by means of a radially inner side-panel 25l and a radially outer sidepanel 252, both said side-panels being secured to the inner and outer edges, respectively, of the valves 250 and 268 and forming therewith the hereinbeforementioned rectangular sleeve characterizing each of the sliding valve assemblies 245, 245a.

Compression valve 250 is disposed adjacent the compression cylinder 212 and moves within the cross-over passage 243 between a chamber-forming position shown in FIGS. l8-20 and a passage-closing position (FIG. 21 Similarly, combustion valve 268 on the combustion side moves between its passage-closing position (FIGS. 18-20) and chamber-forming position (FIG. 21). In order to prevent leakage, suitable valve seats are provided similar to those for the valves 50 and 68 in the embodiment of FIGS. l-6. In addition guide means for ensuring free movement of the valve assemblies 245, 245a should likewise be provided. To this end, and by way of illustration only, the valve assemblies 245, 245a are shown in FIGS. 17 and as having radially projecting guide-ribs 253 adjacent both ends of the valves 250, 268. Guide-ribs 253 slide within corresponding grooves 254 in the walls of the cylinder block. Seals 255 are readily provided between each of valve assemblies 245, 245a and its cross-over passage in order to prevent the gases from leaking from the combustion chamber to the intake chamber and from the compression chamber to the exhaust chamber.

The engine operates in a manner similar to that of the first-described unit shown in FIGS. l-6 insofar as each dual-cylinder assemblage is concerned. Thus, at the point shown in FIG. 19, where the trailing end of piston 228 passes intake port 280 immediately after moving out of engagement with the compression valve 250, valve assembly 245 is held in the position shown in FIG. 19 by engagement of combustion piston 242 with the combustion valve 268, thereby not only holding valve 268 in its passageclosing position but also holding compression-valve 250 in its chamber-forming position. With continued rotation of the rotor 234 a new supply of fuel mixture is drawn through port 280 into the intake chamber behind piston 228, while the previous charge is being compressed ahead of piston 228 into the pressure chamber 244 formed between valves 250 and 268 within valve assembly 245.

After one-half revolution of the rotor, the leading end of compression piston 228 cams the valve assembly 245 to its opposite position within passage 243 as illustrated in FIG. 21. Compression valve 250 is thereby shifted from its chamber-forming position to its passage-closing position as combustion valve 268 moves into its chamber-forming position so that the compressed charge of fuel gases are transferred to the combustion chamber behind piston 242 in cylinder 214. With ignition taking place on completion of compression during the transfer of valve assembly 252 from one position to the other, piston 242 is driven forward by the expanding products of combustion. Up-stream of combustion valve 268, the exhaust gases are swept out 18 the exhaust port 282 by the leading end of combustion piston 242.

It will be noted that in order to maintain sealing engagement between the combustion valve and its piston and between the compression valve and its piston throughout the transfer of the compressed fuel mixture to the combustion cylinder 214, the valve assembly 245 is positioned contined between the sloping ends of the two pistons. The contour of the trailing end of each piston must, therefore, correspond exactly with the camming surface at the leading end of the other. While the trailing end of the combustion piston can not be as abrupt as the one in the arrangement of FIGS. 16, and slight energy loss that may result from the forces of combustion being erexted against a sloping surface on the piston is more than compensated for by the advantages attained in greatly reducing the force required to cam the compression valve 250 from its chamberforming position or its passage-closing position as compared to that required to cam compression valve 50 (FIGS. 5 and 6) through the same movement. This is due to the fact that in the valve-actuating arrangement of FIGS. 16-21, the combustion valve 268 moves simultaneously with the compression valve 250 and, therefore, no matter how highly compressed the fuel is within the pressure chamber 244, the resultant force of such pressure on the compression valve 250 tending to maintain it in its chamber-forming position is counterbalanced by the equal and opposite pressure on the combustion valve 268. Consequently, the only force required to move the valve assembly 245 from the position in which it is shown in FIG. 49 to that of FIG. 21 is the force necessary to overcome: resistance due to engagement of the valve assembly with the ends of the pistons and with the housing in which it is guided.

VALVE ARRANGEMENT OF FIGS. 22-24 In the modified valve arrangement shown purely diagrammatically in FIGS. 22-24, the annular compression and combustion cylinders are disposed side-byside as in the embodiment illustrated in FIGS. 16-21. On the other hand, the valves are pivoted on the engine housing similar to the manner in which they are mounted in the embodiment of FIGS. 1-6. Thus, compression valve 350 is pivotally mounted downstream of a pressure passage 344 in the engine cylinder block 310 for pivotal movement within the compression cylinder 312, and combustion valve 368 is pivotally mounted upstream of the pressure passage 344 for pivotal movement within the combustion cylinder 314. Valves 350 and 368, however, are connected by a link 369 such that movement by one through a portion of its total travel between its chamber-forming and passageclosing positions simultaneously results in a precisely corresponding movement of the other valve. In this instance link 369 is pivotally connected to both valve the the same distance from their respective pivot axes. However, where the total travel of each valve differs, as for example where one cylinder is narrower than the other, the positions at which link 369 is connected to the valves must be adjusted accordingly.

FIG. 22 shows the compression piston 328 and combustion piston 342 in the positions corresponding to the positions of pistons 228 and 242 in FIG. 19 and of pistons 28 and 42 of FIG. 6. Thus, combustion piston 342 has just moved valve 368 into its passage-closing position, which in turn has moved to compression valve 350 into its chamber-forming position, so that compression of the fuel mixture into passage 344 has begun.

FIG. 23 shows pistons 328 and 342 after they have made slightly less than one-half revolution from the position shown in FIG. 22. Piston 328 has begun to move compression valve 350 off its chamber-forming seat and is driving the last of the charge of fuel mixture into passage 344. However, since the combustion valve 368 has begun to move off its passage-closing seat permitting the fuel mixture to flow into the expanding space behind the combustion piston 342, the compressed fuel mixture can be ignited as soon as the inclined cam surface on the compression piston 358 that is exposed to the fuel mixture is equal to, or less than, exposed surface on the trailing end of combustion piston 368.

FIG. 24 shows the compression valve 350 moved by piston 328 to its passage-closing position and combustion valve 368 in its chamber-forming position, ignition having taken place at the peak of compression. The exhaust gases from the previous combustion cycle are starting to be forced out the exhaust port 382, as compression of the next charge of fuel mixture starts on closing of the intake port 380.

It will be understood, that various combinations can be made of the arrangements illustrated in FIGS. 1-6, 16-21 and 22-2 4. For example, the unitary valve assembly of FIGS. 16-21 may be employed in a concentric cylinder arrangement such as that shown in FIG. 3, or the independently mounted valves of FIGS. 5 and 6 may be employed in an engine having the cylinders disposed side-by-side. Similarly, the valve arrangement of FIGS. 22-24 may be employed in place of the valves 50 and S8 of FIGS. 1-6 or in place of the valves 250 and 268 of FIGS. I6-2i.

What is claimed is:

I. In a rotary internal combustion engine having a casing, a rotor journaled for rotation within said casing, at least one elongated, arcuately shaped compression piston rigidly mounted on said rotor for rotation within said casing for compressing a gaseous fuel mixture, at least one elongated, arcuately shaped combustion piston rigidly mounted on said rotor in staggered relation to said compression piston for rotation within said casing and driven by combustion of a compressed charge of fuel mixture, each of said pistons being equal in length in terms of degrees of arc and extending through not substantially more than 180 degrees of arc, said casing providing a compression space within which said compression piston revolves and a combustion space within which said combustion piston revolves, a pres sure passage interconnecting said compression and combustion spaces and having an inlet from said compression space and an outlet to said combustion space, said casing having an intake port opening into said compression space downstream of said inlet and an exhaust port opening from said combustion space upstream of said outlet,

the improvement comprising in combination,

a. a compression valve mounted on said casing adjacent said inlet for movement within said compression space into a chamber-forming position downstream of said inlet and dividing said compression space into a compression chamber upstream thereof and an intake chamber downstream thereof such that upon rotation of said rotor said compression piston compresses a charge of said fuel mixture in said compression chamber into said pressure passage while drawing another charge of fuel mixture into said intake chamber,

b. said compression piston having a surface at its leading end inclined to its path of rotation for camming said compression valve out of its chamber-forming position upon rotation of the leading end of said compression piston into engagement with said compression valve,

c. a combustion valve mounted on said casing adjacent said outlet for movement within said combustion space into a chamber-forming position upstream of said outlet and into a passage-closing position in which it closes said outlet, said combustion valve in its chamber-forming position being disposed such that it constitutes a wall of a combustion chamber downstream thereof and is urged by pressure in said combustion chamber into its chamber-forming position,

d. said combustion piston having a surface at its leading and inclined to its path of rotation for camming said combustion valve into its passageclosing position,

e. said combustion valve being held in its passageclosing position by said combustion piston for a portion of each revolution of said rotor corresponding to the length of such piston,

f. said combustion valve in its passage-closing position constituting a wall of said compression chamber, whereby upon movement of said combustion piston downstream thereof said combustion valve is released by said combustion piston so that it can move into its chamber-forming position.

2. The combination defined in claim I, wherein said compression valve is adapted and arranged to be moved into a passage-closing position by said compression piston upon being cammed out of its chamberforming position, said compression valve being held by said compression piston in its passage-closing position where it constitutes another wall of said combustion chamber for a portion of each revolution of said rotor corresponding to the length of such piston.

3. The combination defined in claim 2, wherein said compression and combustion spaces comprise separate annular cylinders defined within said casing and which further includes a compression-chamber valve-seat formed transversely of said compression cylinder in the walls thereof for sealing engagement with said compression valve when in its chamber-forming position,

and a combustion-chamber valve-seat formed transversely of said combustion cylinder in the walls thereof for sealing engagement with said combustion valve when in its chamber-forming position.

4. The combination defined in claim 3, wherein the trailing end of said combustion piston is disposed substantially radially of said annular combustion cylinder and said pistons are disposed relative to each other in a circumferential direction such that said compression valve is cammed into its passage-closing position while said combustion valve is held in its passage-closing position and the trailing end of said combustion piston moves downstream of said combustion valve substan tially instantaneously after said inlet is closed in order to release said combustion valve so that it is driven into its passage-forming position by the pressure of the gases within said pressure passage.

Claims (30)

1. In a rotary internal combustion engine having a casing, a rotor journaled for rotation within said casing, at least one elongated, arcuately shaped compression piston rigidly mounted on said rotor for rotation within said casing for compressing a gaseous fuel mixture, at least one elongated, arcuately shaped combustion piston rigidly mounted on said rotor in staggered relation to said compression piston for rotation within said casing and driven by combustion of a compressed charge of fuel mixture, each of said pistons being equal in length in terms of degrees of arc and extending through not substantially more than 180 degrees of arc, said casing providing a compression space within which said compression piston revolves and a combustion space within which said combustion piston revolves, a pressure passage interconnecting said compression and combustion spaces and having an inlet from said compression space and an outlet to said combustion space, said casing having an intake port opening into said compression space downstream of said inlet and an exhaust port opening from said combustion space upstream of said outlet, the improvement comprising in combination, a. a compression valve mounted on said casing adjacent said inlet for movement within said compression space into a chamber-forming position downstream of said inlet and dividing said compression space into a compression chamber upstream thereof and an intaKe chamber downstream thereof such that upon rotation of said rotor said compression piston compresses a charge of said fuel mixture in said compression chamber into said pressure passage while drawing another charge of fuel mixture into said intake chamber, b. said compression piston having a surface at its leading end inclined to its path of rotation for camming said compression valve out of its chamber-forming position upon rotation of the leading end of said compression piston into engagement with said compression valve, c. a combustion valve mounted on said casing adjacent said outlet for movement within said combustion space into a chamber-forming position upstream of said outlet and into a passage-closing position in which it closes said outlet, said combustion valve in its chamber-forming position being disposed such that it constitutes a wall of a combustion chamber downstream thereof and is urged by pressure in said combustion chamber into its chamber-forming position, d. said combustion piston having a surface at its leading and inclined to its path of rotation for camming said combustion valve into its passage-closing position, e. said combustion valve being held in its passage-closing position by said combustion piston for a portion of each revolution of said rotor corresponding to the length of such piston, f. said combustion valve in its passage-closing position constituting a wall of said compression chamber, whereby upon movement of said combustion piston downstream thereof said combustion valve is released by said combustion piston so that it can move into its chamber-forming position.

2. The combination defined in claim 1, wherein said compression valve is adapted and arranged to be moved into a passage-closing position by said compression piston upon being cammed out of its chamber-forming position, said compression valve being held by said compression piston in its passage-closing position where it constitutes another wall of said combustion chamber for a portion of each revolution of said rotor corresponding to the length of such piston.

3. The combination defined in claim 2, wherein said compression and combustion spaces comprise separate annular cylinders defined within said casing and which further includes a compression-chamber valve-seat formed transversely of said compression cylinder in the walls thereof for sealing engagement with said compression valve when in its chamber-forming position, and a combustion-chamber valve-seat formed transversely of said combustion cylinder in the walls thereof for sealing engagement with said combustion valve when in its chamber-forming position.

4. The combination defined in claim 3, wherein the trailing end of said combustion piston is disposed substantially radially of said annular combustion cylinder and said pistons are disposed relative to each other in a circumferential direction such that said compression valve is cammed into its passage-closing position while said combustion valve is held in its passage-closing position and the trailing end of said combustion piston moves downstream of said combustion valve substantially instantaneously after said inlet is closed in order to release said combustion valve so that it is driven into its passage-forming position by the pressure of the gases within said pressure passage.

5. The combination defined in claim 3, wherein said cylinder casing includes a wall common to both said cylinders and said pressure passage is formed in said common wall, said inlet being formed in the compression-cylinder side of said common wall and said outlet being an enlarged opening to said combustion cylinder directly opposite said inlet, said valves being pivotally mounted on said common wall on opposite sides thereof and said combustion valve having a free end disposed downstream of said combustion cylinder when in its passage-closing position.

6. The combination defined in claim 5, wherein the trailing end of said combustion piston is disposeD substantially radially of said annular combustion cylinder and said pistons are disposed relative to each other in a circumferential direction such that said compression valve is pivoted into its passage-closing position while said combustion valve is held by said combustion piston in its passage-closing position and the trailing end of said combustion piston moves downstream of the free end of said combustion valve substantially instantaneously after said inlet is closed in order to release said combustion valve so that it is pivoted by the pressure within said pressure passage into its passageforming position.

7. The combination defined in claim 3, wherein said cylinders are disposed concentrically of each other one within the other.

8. The combination defined in claim 4, wherein said cylinders are disposed concentrically of each other one within the other.

9. The combination defined in claim 5, wherein said cylinders are disposed concentrically of each other one within the other.

10. The combination defined in claim 6, wherein said cylinders are disposed concentrically of each other one within the other.

11. The combination defined in claim 7, wherein said compression cylinder is the inner one of said concentric cylinders.

12. The combination defined in claim 3, wherein said cylinders are disposed side-by-side axially of said rotor,

13. The combination defined in claim 4, wherein said cylinders are disposed side-by-side axially of said rotor.

14. The combination defined in claim 5, wherein said cylinders are disposed side-by-side axially of said rotor.

15. The combination defined in claim 6, wherein said cylinders are disposed side-by-side axially of said rotor.

16. The combination defined in claim 5, wherein said common wall is provided with a removable wall-section, said pressure passage being formed in said wall-section and said valves being mounted on said wall-section such that said wall-section and valves together comprise a subassembly of said engine which is removable as a unit for cleaning, repair or replacement.

17. The combination defined in claim 6, wherein said common wall is provided with a removable wall-section, said pressure passage being formed in said wall-section and said valves being mounted on said wall-section such that said wall-section and valves together comprise a subassembly of said engine which is removable as a unit for cleaning, repair or replacement.

18. The combination defined in claim 3, which includes a plurality of said pressure passages each having a said inlet and a said outlet, said inlets being spaced equally from each other along said compression cylinder and said outlets being spaced equally from each other along said combustion cylinder, and which further includes one of said compression and one of said combustion valves for each of said pressure passages, said pistons being substantially equal in length to the intervals between said inlets and outlets, respectively.

19. The combination defined in claim 4, which includes a plurality of said pressure passages each having a said inlet and a said outlet, said inlets being spaced equally from each other along said compression cylinder and said outlets being spaced equally from each other along said combustion cylinder, and which further includes one of said compression and one of said combustion valves for each of said pressure passages, said pistons being substantially equal in length to the intervals between said inlets and outlets, respectively.

20. The combination defined in claim 5, which includes a plurality of said pressure passages each having a said inlet and a said outlet, said inlets being spaced equally from each other along said compression cylinder and said outlets being spaced equally from each other along said combustion cylinder, and which further includes one of said compression and one of said combustion valves for each of said pressure passages, said pistons being substantially equal in length to the intervals between saId inlets and outlets, respectively.

21. The combination defined in claim 6, which includes a plurality of said pressure passages each having a said inlet and a said outlet, said inlets being spaced equally from each other along said compression cylinder and said outlets being spaced equally from each other along said combustion cylinder, and which further includes one of said compression and one of said combustion valves for each of said pressure passages, said pistons being substantially equal in length to the intervals between said inlets and outlets, respectively.

22. The combination defined in claim 3, wherein said combustion cylinder is provided with an injection port for introducing a charge of combustion-regenerating material directly into said combustion chamber for burning the products of combustion therein.

23. The combination defined in claim 4, wherein said combustion cylinder is provided with an injection port for introducing a charge of combustion-regenerating material directly into said combustion chamber for burning the products of combustion therein.

24. The combination defined in claim 5, wherein said combustion cylinder is provided with an injection port for introducing a charge of combustion-regenerating material directly into said combustion chamber for burning the products of combustion therein.

25. The combination defined in claim 6, wherein said combustion cylinder is provided with an injection port for introducing a charge of combustion-regenerating material directly into said combustion chamber for burning the products of combustion therein.

26. The combination defined in claim 3, which includes means for connecting said compression and combustion valves, said connecting means and valves forming a valve assembly in which said valves move in unison, each of said pistons having a surface at its trailing end corresponding exactly with said surface at the leading end of the adjacent one of said pistons in the other cylinder and each of said trailing ends being positioned with respect to the leading end of said adjacent piston such that engagement is maintained between each of said pistons and the corresponding one of said valves as said valves are moved from one position to the other.

27. The combination defined in claim 26, wherein said cylinder casing includes a wall common to both said cylinders, said inlet being formed in the compression-cylinder side of said common wall and said outlet opening into said combustion cylinder on the side of said common wall directly opposite said inlet, said valve assembly comprising a rigid member slidably mounted within said common wall, said valves comprising oppositely disposed side-walls of said valve assembly which extend obliquely to said annular cylinders and said connecting means comprising rigid sidepanels of said valve assembly with said pressure passage formed between said side-walls and said side-panels within said valve assembly, and guide means within said common wall for slidably receiving said valve assembly for reciprocal movement between fixed limits, whereby in one of such limits of movement of said valve assembly said compression valve is disposed in sealing engagement with its compressionchamber valve-seat and said combustion valve is disposed in sealing engagement with said outlet, while in the other limit of movement of said valve assembly said compression valve is disposed in sealing engagement with said inlet while said combustion valve is disposed in sealing engagement with said combustion-chamber valve-seat.

28. The combination defined in claim 5, which includes a link pivotally connecting said compression and combustion valves such that said valves move in unison, each of said pistons having a surface at its trailing end corresponding exactly with said surface at the leading end of the adjacent one of said pistons in the other cylinder and each of said trailing ends being positioned with respect to the leading end of said adjacent piston such that engagement is maiNtained between each of said pistons and the corresponding one of said valves as said valves are moved from one position to the other.

29. The combination defined in claim 26, wherein said cylinder casing includes a wall common to both said cylinders and having a removable wall-section, said pressure passage being disposed within said wall-section with said inlet in the compression-cylinder side thereof and said outlet opening into said combustion cylinder on the side of said wall-section directly opposite said inlet such that said wall-section and valve assembly comprise a subassembly of said engine which is removable as a unit for cleaning, repair or replacement.

30. A valve for a rotary-piston type of machine, such as an engine or air compressor, such machine having a cylinder block forming an annular cylinder, an annular piston rotatably mounted therein and a pressure passage formed within said cylinder block having an opening into said cylinder, said valve being adapted and arranged for mounting within said cylinder block for reciprocation between a chamber-forming position and a passage-closing position and having a wall portion capable of dividing said annular cylinder circumferentially into separate chambers on opposite sides of said wall portion when said valve is disposed in its said chamber-forming position, said wall portion being so disposed as to be positively moved by said piston from its said chamber-forming position in said cylinder into engagement with the opening to said passage in order to seal said passage from said cylinder.

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