Rotary internal combustion engine and rotary internal combustion engine cycle

[0002] The present invention relates to internal combustion engines and in particular a rotary internal combustion engine and rotary internal combustion engine cycles.

[0003] The rotary internal combustion engine and cycle is superior in many ways to the conventional reciprocating piston-type engine. They possess fewer parts, are of low weight, simple in design, have superior breathing and therefore greater efficiency, have no valves and do not experience a reciprocating imbalance. Various designs of rotary internal combustion engines are known most of which comprise a rotor eccentrically mounted within a rotor chamber. In many, the rotor has a plurality of slots fitted with sliding vanes in order to create the working chambers of the engine as the rotor rotates within the rotor chamber. However, there are numerous shortcomings associated with the known art such as inadequate sealing between the working chambers of the engine leading to combustion gas leakage between working chambers of the engine, the premature retraction of the radially mounted members, complexity of design, inordinate frictional wear of component parts, and an inefficient conversion of chemical energy to mechanical energy.

[0004] One example of the known art is Canadian Letters Patent 1,248,029 entitled “Rotary Internal Combustion Engine” issued on Sep. 3, 1981 to Aase. The Aase patent discloses an engine which relies upon a very complex rotor design, comprising sliding cylinder sleeves within the rotor receiving members that define the working chambers of the engine. This design is very complex and hence may be very expensive to manufacture. Furthermore there are a large number of moving parts in the engine design all of which are subject to frictional wear. Finally, the size of the combustion chamber is limited and therefore the conversion of chemical fuel energy to mechanical rotational energy may be less than optimal.

[0005] The present invention seeks to overcome the disadvantages of known internal combustion rotary engines.

[0006] An object of the present invention is to provide an improved rotary internal combustion engine and an improved rotary internal combustion engine cycle.

[0007] In accordance with one aspect of the present invention there is provided a rotary internal combustion engine comprising an engine casing within which is mounted a cylindrical rotor co-axially fixed to a drive shaft and adapted to receive a plurality of slidable and retractable vanes. The rotor is eccentrically and rotatably mounted inside a circular rotor chamber. In cross-section, the rotor chamber wall is thicker at the side at which combustion takes place to accommodate the pressures resulting from the combusting fuel/air mixture. The slidable retractable vanes are mounted in the rotor in a staggered and radial arrangement substantially forming a “Y” shape in cross-section. Cams are coupled to the sliding and retracting vanes by connecting rods to control their sliding and retracting movements. These sliding and retracting movements define the working chambers of the engine as the rotor rotates. The working chambers comprise a fuel/air mixture intake chamber, a compression chamber, a combustion chamber and an exhaust chamber.

[0008] In one embodiment of the present invention, there is provided a fuel/air mixture supply using either carburation or fuel injection means for providing a suitable fuel/air mixture to the intake and combustion chambers. The fuel/air mixture is ignited using a spark plug or compression ignition means. Conveniently, gaseous products of combustion are removed from the engine through an exhaust gas system comprising a series of interconnected orifices and ports and an intake/exhaust vane. The moving engine parts are adequately lubricated. Those portions of the engine which are in communication with each other and require to be sealed in order for the engine to operate are so sealed.

[0009] The engine also has a coolant circulating system to remove combustion heat from the engine in operation.

[0010] In accordance with another aspect of the present invention there is provided a rotary internal combustion engine cycle wherein the operation thereof is defined by the following phases: intake phase, compression phase, combustion and power phase and exhaust phase. The combustion phase occurs over at least 180 degrees of rotor rotation and as much as 200 degrees of rotation. All four phases are repeated over each cycle of 360 degrees of rotation.

[0011] Advantages of the present invention are a more efficient conversion of chemical fuel energy to mechanical energy by the increased combustion phase over at least 180 degrees of rotation; fewer mechanical parts to wear; sealing and anti-friction means to further improve the operation of the engine.

[0012] The present invention will be further understood from the following description with references to the drawings in which:

[0013] FIG. 1 is a cross-sectional axial view of an embodiment of the present invention showing the intake-exhaust vane at 90 degrees of rotation.

[0014] FIG. 2 is a cross-sectional radial view of the embodiment of FIG. 1 showing the torque vane at 90 degrees of rotation.

[0015] FIG. 3 is a cross-sectional radial view of one embodiment of FIG. 1 showing the torque vane at 270 degrees of rotation.

[0016] FIG. 4 is a cross-sectional radial view of one embodiment of FIG. 1 showing the torque vane at 300 degrees of rotation.

[0017] FIG. 5 is a cross-sectional radial view of one embodiment of FIG. 1 showing the torque vane at 0 degrees of rotation.

[0018] FIG. 6 is a cross-sectional radial view of one embodiment of FIG. 1 showing the intake/exhaust vane at 180 degrees of rotation.

[0019] FIG. 7 is a cross-sectional axial view of one embodiment of FIG. 1 showing the pressure containment vane at the bottom end of its travel.

[0020] FIG. 8 is a cross-sectional radial view of one embodiment of FIG. 1 showing the torque vane at 180 degrees of rotation.

[0021] FIG. 9 is a cross-sectional radial view of one embodiment of FIG. 1 showing the torque vane at 225 degrees of rotation.

[0022] FIG. 10 is a cross-sectional axial view of one embodiment of FIG. 1

[0023] FIG. 10A is a cross-sectional radial view of one embodiment of FIG. 1 showing the flow of intake gases.

[0024] FIG. 11 is a cross-sectional radial view of one embodiment of FIG. 1 showing the flow of exhaust gases.

[0025] FIG. 12 is a cross-sectional radial view of one embodiment of FIG. 1.

[0026] FIG. 13 is a cross sectional radial view of one embodiment of FIG. 1 showing cam 17.

[0027] FIG. 14 is a cross-sectional axial view of one embodiment of FIG. 1

[0028] FIG. 15 is a cross-sectional radial view of one embodiment of FIG. 1 showing cam 18.

[0029] FIG. 16 is a cross-sectional axial view of one embodiment of FIG. 1.

[0030] FIG. 17 is a cross-sectional radial view of one embodiment of FIG. 1 showing cam 19.

[0031] FIG. 18 is a front and side view of one embodiment of a vane of one embodiment of FIG. 1.

[0032] FIG. 19 is a cross-sectional radial view of one embodiment of FIG. 1 showing the liquid coolant jacket.

[0033] Referring to FIG. 1 there is illustrated a rotary internal combustion engine assembly (1) in accordance with an embodiment of the present invention. The engine comprises a engine casing (300). The ends of the engine casing are closed by way of main shaft bearing housings (48), is apertured at their center to receive ends of rotor shaft (6). A cylindrical rotor (3) is co-axially mounted on the shaft (6). The ends of the shaft (6) are bevelled and the bevelled ends are mounted on main shaft bearings (46) housed in main shaft bearing housings (48). Oil seals (47) are provided to seal the ends of the shaft against the main shaft bearing housing. Engine rotor (3) is mounted eccentrically within circular rotor chamber (2). Within each of the ends of the engine casing (300) are located cams (17 intake/exhaust, 18 torque and 19 pressure containment).

[0034] Referring to FIG. 2, the rotor (3) has slots (9A, 10A and 11A) to receive slidable and retractable vanes (9, 10 and 11). As more fully described below, the vane (9) functions as the intake/exhaust vane, the vane (10) functions as the torque vane and the vane (11) functions as the pressure containment vane. The rotor (3) is eccentrically and rotatably mounted inside a circular rotor chamber (2) such that the rotor, as it rotates in the direction of the arrow (200), is in continual sliding contact with the inside wall of the rotor casing (23) at the rotor/rotor casing seal (27). Sealing is accomplished using a close tolerance gap between the rotor and the rotor casing. A TEFLON™ or other type of inorganic seal is installed at point (27). The rotor is also notched at (30) which, as more filly described below, forms part of the combustion chamber. Combustion takes place at the rotor/rotor casing seal (27) below the spark plug (28). Since this is the area in which the rotor casing will experience the greatest pressures, the casing is thicker here than elsewhere to withstand these pressures. FIG. 2 also shows intake orifice (32).

[0035] Slidable, retractable vanes (9, 10, 11) are connected to respective cam axles (13, 14 and 15) by connecting rods (12). Cam axles (13, 14 and 15) are contained in bores (13A, 14A and 15A respectively). Due to the elongated shape of the bores, cam axles (13, 14 and 15) are permitted a reciprocating motion within bores (13A, 14A and 15A). This reciprocating motion is transmitted to the vanes by the connecting rods as a sliding motion causing the vanes to extend out of or retract into their respective slots. This in turn defines the working chambers of the engine as the rotor rotates, as more fully described below.

[0036] In operation, the rotary internal combustion engine includes an intake phase, compression phase, combustion and power phase and exhaust phase.

[0037] The Intake Phase

[0038] As indicated above, and referring to FIG. 2, the working chambers of the engine are defined by the operative relationship between the rotating rotor (3), the slidable retractable vanes (9, 10 and 11) and the cam axles (13, 14 and 15). Referring to FIG. 3, the intake phase commences as the intake/exhaust vane (9) has sweeps past the “0” degree point (27). As the rotor (3) rotates, intake chamber (20) increases in volume, creating a partial vacuum, drawing a fuel/air mixture into the intake chamber (20) by way of an intake orifice (31) in serial communication with intake port (32), intake ring (Shown in FIG. 10A as Item 4) and intake rube (Shown in FIG. 10A as Item 35). The volume of the intake chamber (20) is initially defined as the volume between the lagging face (24) of the intake/exhaust vane (9) and the rotor/rotor casing seal (27).

[0039] In FIG. 4, the intake/exhaust vane (9) is shown having advanced to the 90 degree position. The distal end of vane (9) remains in sliding and sealing contact with the inside wall of the rotor casing. The volume of the intake chamber continues to expand drawing in more fuel/air mixture as shown.

[0040] Referring to FIG. 5, the volume of the intake chamber (20) continues to expand as rotor (3) rotates.

[0041] Referring to FIG. 6, the intake/exhaust vane (9) has advanced to the 180 degree position. The distal end of intake/exhaust vane (9) remains in sealing contact with the inside surface of the rotor chamber. Vane (9) is at its maximum extension from its slot (9A). Cam 13 is at its maximum inboard position within bore (13A). Torque vane (10) has swept past the “0” degree point (27) and the volume of the intake chamber (20) is now defined as the volume between the leading face (21) of torque vane (10) and the lagging face (24) of intake/exhaust vane (9).

[0042] The intake chamber is endosed on its sides by the engine stationary intake case (Shown in FIG. 1 as Item 7) and the engine stationary exhaust case (Shown in FIG. 1 and Item 8).

[0043] Referring to FIG. 2, the intake/exhaust vane (9) is now located at the 240 degree position. The torque vane (10) is at the 90 degrees position. The volume of the intake chamber (20) is at its maximum volume. As more fully described below, the compression phase will now commence. Intake port (32) and intake orifice (31) are no longer in communication with intake ring (Shown in FIG. 1 as Item 4) and the intake chamber is sealed for pressurization.

[0044] Additional details of the fuel/air intake phase are described with reference to FIG. 1 and FIG. 10A. A fuel/air mixture is provided by way of carburation means or fuel injection mean into intake tubes (35). Intake tube (35) penetrates rotor intake case (7) and is in constant communication with rotor ported intake annulus (4A). Intake annulus (4A) is within rotor intake case (7). Intake orifice (31) in the rotor (3) is in communication with intake port (32). As the rotor rotates during the intake phase, rotor intake port (32) remains in communication with intake annulus (4A) drawing the fuel/air mixture into the intake chamber (20).

[0045] The Compression Phase

[0046] Referring to FIG. 8, the intake/exhaust vane (9) sweeps towards the rotor/rotor casing seal (27) at the “0” degree position and the torque vane (10) is at the 180 degree position. The volume of the sealed compression chamber (60) is decreasing and the fuel/air mixture therein is becoming pressurized. The intake orifice (31) and intake port (32) are no longer in communication with the intake annulus (Shown in FIG. 1 as Item 4). Pressure containment vane (11) is in its retracted position within slot (11A).

[0047] Referring to FIG. 9, torque vane (10) is at the 225 degree position in a sealed and sliding contact with the inner wall of the rotor chamber (23). As the distance between the surface of the rotor and the inner wall of the rotor chamber decreases, torque vane (10) retracts into its slot (10A). The volume of the compression chamber (60) is now defined as the volume between the rotor/rotor casing seal (27) and the leading face (21) of torque vane (10). Note that pressure containment vane (11) commences its extraction from its slot (11A). Intake/exhaust vane (9) has swept over seal (27) and is substantially in its fully retracted position.

[0048] Referring to FIG. 3, torque vane (10) is at the 270 degree position and compression chamber (60) is approaching its minimum volume. The fuel/air mixture within the compression chamber (60) is reaching its maximum pressure. Pressure containment vane (11) is fully extended from slot (11A) and its tip is in a sliding and sealed contact with the inner wall of the rotor chamber. The space between the lagging face (22) of torque vane (10) and the leading face (26) of pressure containment vane (11) and the volume formed by the hollow (30) comprise the combustion chamber (52).

[0049] Referring to FIG. 4, torque vane (10) has commenced its retraction in slot (10A). As torque vane (10) retracts, the pressurized air/fuel mixture is further compressed within compression chamber (20).

[0050] The Combustion Phase and Power Phase

[0051] Referring to FIG. 5, torque vane (10) is at the “0” degree position (27) and fully retracted. The pressurized fuel/air mixture has now been transferred to the combustion chamber (52).

[0052] Referring to FIG. 6, the combustion chamber (52) containing the pressurized fuel/air mixture is at the “0” degree position (27) and directly below the spark plug (28). The spark plug fires and ignites the fuel/air mixture which combusts and the products of combustion begin to expand, commencing the power phase of engine operation.

[0053] Referring to FIG. 2, during the power phase of engine operation the products of combustion will expand to fill the combustion chamber (52). The gases will be expanding against the rotor casing/ rotor seal (27) as well as the lagging face (22) of torque vane (10), however, since the area represented by the lagging face (22) of torque vane (10) is greater than the area presented by the seal (27) the gases will drive the vane in a clock-wise direction imparting rotational torque to the rotor (3) in the direction after the arrow (200). Pressure containment vane (11) remains retracted into its slot (11A) after passing rotor casing/rotor seal (27).

[0054] Referring to FIG. 8, the torque vane (10) is in the 180 degree position. The combustion gases in combustion chamber (52) continue to act against the lagging face (22) of torque vane (10). Therefore, one of the main advantages of this engine cycle is that power is transmitted to the torque vane by the expanding gases over at least 180 degrees of engine rotation as many as 200 degrees of engine rotation thus increasing the overall torque of the engine.

[0055] The Exhaust Phase

[0056] Referring to FIG. 9, the exhaust phase of engine operation commences when torque vane (10) is located at the 225 degree position. The pressure containment vane (11) begins to extend from slot (11A) as the intake/exhaust vane (9) sweeps past the rotor casing/rotor seal (27) at the “0” degree position. Exhaust gas chamber (53) is near its maximum volume and exhaust gas is forced into exhaust orifice (33) and into exhaust port (34). Exhaust port (34) is in communication with the exhaust annulus (Shown in FIG. 10 as Item 34A) and exhaust gases are driven out of the rotor chamber through exhaust tubes (Shown in FIG. 10 as Item 36).

[0057] Referring to FIG. 3 intake/exhaust vane (9) is sweeping towards the 90 degree position and pressure containment vane (11) is sweeping towards the 270 degree position. The tops of both vanes are in sliding and sealing contact with the inner wall of the rotor chamber. The exhaust chamber (53) is defined as that volume enclosed by the lagging face (26A) of the pressure containment vane (11) and the leading face (25) of the exhaust/intake vane (9).

[0058] Referring to FIG. 5, intake/exhaust vane (9) is sweeping towards the 180 degree position and pressure containment vane (11) is sweeping towards the “0” degree position. The volume of the exhaust chamber (53) gets smaller as the rotor rotates and exhaust gases are forced into the exhaust orifice (33).

[0059] Referring to FIG. 2, pressure containment vane (11) has swept past the rotor/rotor casing seal (27) and the volume of the exhaust chamber (53) is now defined as that volume between the leading face (25) of the intake/exhaust vane (9) and the rotor/rotor casing seal (27). As the rotor continues to rotate clockwise the exhaust gases will be forced into the exhaust orifice (33) until all exhaust gas is forced out of the exhaust chamber as intake/exhaust vane (9) sweeps past seal (27). Once intake/exhaust vane (11) sweeps beyond seal (27), the exhaust port (34) will no longer be in communication with exhaust annulus (Shown in FIG. 1 as Item 34A).

[0060] Additional details of the exhaust phase are described with reference to FIG. 10 and FIG. 11. FIG. 10 shows the leading face (25) of intake/exhaust vane (9) coming toward the viewer. As the rotor (3) rotates exhaust gases are forced into exhaust orifices (33) and rotor exhaust port (34). During the exhaust phase, exhaust port (34) is in constant communicating with exhaust annulus (34A). Exhaust tubes (36) penetrate exhaust casing (8) and are in constant communication with the exhaust annulus (34A) thus there is a direct pathway for exhaust gases to be forced out of the exhaust chamber. In FIG.1, three exhaust tubes (36) are shown penetrating exhaust casing (8) and in communication with exhaust annulus (34A). Rotor exhaust port (34) is in communication with the exhaust annulus (34A) during the exhaust phase. Shown in FIG. 11 is exhaust ring (5) which bounds exhaust annulus (34A).

[0061] Cams and Cam Pathways

[0062] The operable relationship between the cams, Cam axles and cam pathways is described below.

[0063] Referring to FIG. 12, the intake/exhaust vane (9) is shown at the 90 degree position, in its fully extended position, and in sliding and scaling contact with the inner wall of the rotor casing (2). Combustion chamber (52) is shown at the 270 degree position. Intake/exhaust vane (9) is attached to a pair of rods (12). Rods (12) penetrate the rotor (3) and drive shaft (6) through ducts (44) sufficiently sized to permit the passage of the rods (12) and adequate lubrication of the rods within the ducts. Rods (12) are attached at their other ends to cam axle (13) which is shown housed in bore (13A). Coinciding with the maximum extension of intake/exhaust vane (9) cam axle (13) is shown at its inboard position in bore (13A). As is apparent from FIG. 12, the motion of the vane (9) is determined by the motion of the cam axle (13) in the axle bore (13A). The reciprocating cam axle (13) is biased by spring (49).

[0064] Cam pathway (17) is illustrated in FIG. 12 and FIG. 13. Lug (101) is shown mounting anti-friction bearing (16). Lug (101) and bearing (16) follow the pathway defined by cam surface (56). As shown in FIG. 2, when the anti-friction bearing (16) is at the 180 degree position in its rotation, the cam axle will be forced against its spring (49) to its inboard position in the cam axle bore which will coincide with the vane (9) being at its fully extended position.

[0065] The operative relationship between the torque vane (10) and its cam axle (14) is similarly described with reference to FIG. 14 and FIG. 15. Torque vane (10) is shown at its 270 degree position. Facing the viewer is the lagging face (22) of torque vane (10) moving away from the viewer. Torque vane (10) is attached to cam axle (14) by way of a pair of rods (12) which penetrate both the rotor (3) and the main shaft (6) by way of ducts (44) which are adequately lubricated. The torque vane (10) is shown in a partially extended position and therefore cam axle (14) is shown at its inboard position within its axle bore (14A) and compressed against spring (49). Lug (110) is illustrated mounting anti-friction bearing (16). Anti-friction bearing (16) is shown in cam pathway (18). The operative relationship between the cam axle (14) and the cam pathway (18) is illustrated in FIG. 15 where lug (110) attached to cam axle (14) is shown mounting anti-friction bearing (16). Bearing (16) is in rotational engagement with cam surface (56) and as the rotor rotates cam surface determines the position of cam axle (14) within its bore (14A) and therefore the position of torque vane (10).

[0066] The operative relationship between pressure containment vane (11), cam axle (15) and cam (19) is described with reference to FIG. 16 and FIG. 17. Pressure containment vane (11) is shown at its 270 degree position and fully extended so that its tip is in slidable and sealing contact with the inner surface of the rotor chamber (2). Pressure containment vane (11) is connected to cam axle (15) by way of a pair of rods (12) penetrating rotor (3) and drive shaft (6) through ducts (44). Ducts (44) also provide lubrication for the rods (12). Since pressure containment vane (11) is at its maximum extension, cam axle (15) must be at its maximum inboard position within cam axle bore (15A) and compressed against spring (49). Lug (115) is shown mounted to cam axle (15) anti-friction bearing (16) is shown mounted to lug (115). The operative relationship between lug (115), anti-friction bearing (16) and cam (18) is described with reference to FIG. 17. FIG. 17 illustrates lug (115) mounting anti-friction bearing (16). Anti-friction bearing (16) is in a rotating engagement with cam surface (56). As the rotor rotates, lug (115) and bearing (16) travel cam path (56). Lug (115) transmits its rotational movement as reciprocating movements of cam axle (15) within axle bore (15A). This reciprocating movement is transferred to pressure containment vane (11) by way of connecting rods (12).

[0067] Referring to FIG. 18, the slidable and retractable vanes (of which (11) is shown) comprise rectangular members. With a thickness sufficient to provide for adequate sealing between the working chambers of the engine when the vanes are in their extended positions and allow the mounting of sealing means thereon. As described above, the vanes are connected to cam axles by rods (12) that transmit the reciprocating motion of the cam axels to the vanes as the engine rotates. The vanes (9, 10 and 11) are mounted at their inboard ends to said rods (12) by a dovetail attachment (11B). A seal (29) is mounted to the outboard ends of the vanes so that the vane can remain in sliding contact with the inside surface of the rotor chamber. The seals may consist of one of or a combination of a labyrinth, an inorganic seal or a TEFLON™ key and the tip of the sealing and anti-friction means are curved (102) to coincide with the curvature of the inside surface of the rotor chamber.

[0068] It will be understood by a person skilled in the art that a seal must be provided to maintain the proper gas and fluid pressures within the operating engine. Seals shown in the figures include: rotor/rotor casing seal (Shown in FIG. 2 as Item 27), vane tip seal (Shown in FIG. 18 as Item 29), labyrinth, TEFLON™ or polymer seal (Shown in FIG. 1 as Item 43) and oil seal (Shown in FIG. 1 as Item 47).

[0069] It will be understood by a person skilled in the art that an adequate heat rejection system must be provided in order to remove the heat of fuel combustion from the engine. Referring to FIGS. 1 and 19, a liquid coolant jacket (37) is shown between the outer casing of the engine assembly (1) and the engine rotor casing (2). It will be further understood by a person skilled in the art that the coolant will circulate through its jacket under pressure and therefore be connected to a coolant pump.

[0070] The rejected heat will be transported by the coolant from the engine to a radiator in a closed loop system.

[0071] It will be understood by a person skilled in the art that adequate lubrication must be provided between those moving parts which are in sliding or frictional contact with each other. The present invention discloses a plurality of lubricating devices which, referring to the figures include: oil feed passage through the shaft/rotor/cam axles (Shown in FIG. 1 as Item 38), oil scavenge system (Shown in FIG. 1 as Item 39), oil lines communicating with a pumping heat rejection system (Shown in FIG. 1 as Item 42) to provide for oil cooling, oil seal (Shown in FIG. 1 as Item 47), rotor oil cooling passage (Shown in FIG. 1 as Item 50) and oil drain passage through the intake exhaust cam (Shown in FIG. 1 as Item 51).

[0072] It will be further understood by a person skilled in the art that spark ignition timing and rotor balancing will be provided.