WO1997010419A1

WO1997010419A1 - Internal combustion rotary engine with variable compression ratio

Info

Publication number: WO1997010419A1
Application number: PCT/US1996/014844
Authority: WO
Inventors: Gholam Ali Kiyoumars Saham
Original assignee: Lari, Hassan, B.
Priority date: 1995-09-14
Filing date: 1996-09-13
Publication date: 1997-03-20
Also published as: AU6979296A

Abstract

An internal combustion rotary engine with a double gimbal (34) is disclosed where the compression ratio of the engine may be changed while the engine is operating. The engine has two rotors (42, 44), each with two spokes (50, 52). The spokes of the rotors interleave to define chambers within the engine housing. Each rotor is connected to a different shaft (46, 48), one concentrically arranged within the other. As the spokes revolve about their respective shafts, their angular velocity oscillates as a result of the intake, compression and combustion of the fuel-air mixture, and exhausting of waste gases. Because of this oscillation and because each pair of spokes is 90° out of phase with the other pair, the sizes of the chambers alternatively increase and decrease as each spoke alternately catches up with and then falls behind the one adjacent to it.

Description

INTERNAL COMBUSTION ROTARY ENGINE WITH VARIABLE COMPRESSION RAΗO

BACKGROUND OF THE INVENTION

1. Field of the Invention:

The present invention relates to internal rotary combustion engines, rotary pumps and compressors, and more specifically, to an internal combustion rotary engine with a variable compression ratio.

2. Discussion of Background:

The internal combustion engine is one of the most reliable and most widely used power sources in the world. It is used to power a vast majority of automobiles, light trucks, and light aircraft, as well as pumps, compressors, generators, conveyors, and a variety of other devices.

An internal combustion engine can be classified as either a spark- ignition engine or a compression-ignition engine, depending on how the mixture of fuel and air is ignited. In a spark-ignition engine, the mixture is ignited electrically, by a spark plug. In a compression-ignition engine the air is compressed so that it heats to a temperature above the ignition temperature. Fuel is injected into the compressed air and the mixture then ignites spontaneously.

Two- and four-stroke engines as well as rotary gasoline engines operating on a Otto cycle are usually classified as spark ignition engines. Diesel engines are categorized as compression ignition engines.

Internal combustion engines operating in this fashion operate on the Otto cycle. These Otto engines are in the form of reciprocating engines or rotary engines which typically function on the two- or four-stroke principle. The four-stroke principle includes the steps of fuel intake, compression, ignition, and combustion. In these reciprocating engines, a crankshaft or camshaft is driven via several pistons which move radially with respect to the shaft axis and transfer their radial motion to circular motion with piston rods and a cam shaft. This engine has disadvantages in that several pistons have to be provided in order to achieve a particular engine performance, where each piston is housed in a cylinder and has its own inlets and outlets and also its own ignition system. The coordination of the different components as each cylinder moves through the four phases of the Otto cycle must be precise for the engine to run smoothly. A rotary engine whose piston executes a continuous rotary movement is also well known. An embodiment of this is the Wankel engine, in which a rotary piston is mounted eccentrically in a trichoidal housing and has the shape of an equilateral triangle which rotates by turning about a midpoint, which also simultaneously executes a rotary movement. The working process is based on the four-stroke principle and takes places in the working chambers which are located between the rotary piston and the housing wall. These chambers become larger and smaller, thus affecting gas exchange, i.e., intake, compression, expansion, and exhaust, with the aid of inlet and outlet slots in the housing wall which are controlled by the rotary piston. The particular advantages of a rotary engine over the reciprocating engine are the smaller number of components, the removal of larger, linearly moving masses, the removal of the valve system, and the smaller size and lower weight of the engine and its components.

The compression ratio of an internal combustion engine is the ratio of the chamber volume at the beginning of the compression process to the volume at the end of the compression process. Theoretically, in an ideal, cold-air Otto cycle, the thermal efficiency of an ideal spark ignition engine is solely a function of the compression ratio. However, a real internal combustion engine is far more complex, and other factors including engine design, carburization, and friction have a significant impact on engine efficiency. Nevertheless, any engine design that increases the compression ratio should result in an increased engine efficiency and increased fuel economy. The upper limit of the compression ratio is limited somewhat by the technical aspects of the engine design, such as pre-ignition, which is the ignition of a fuel air mixture from the high temperature caused by the high compression before the spark plug can ignite that mixture, and is the cause of engine "knock."

In a compression ignition engine, a diesel engine, the typical compression ratio can be as much as twice that of a typical spark ignition system. Even considering this, the diesel engine is similar in most respects to the Otto cycle and thus, as the compression ratio is increased, the thermal efficiency of the engine is also increased.

Increasing the compression ratio of an engine not only increases the thermal efficiency, but also increases the mean effective pressure (MEP). The mean effective pressure is a fictitious pressure that is proportional to the net work of the engine, but is also dependent on the displacement volume during the power stroke of the cylinder or rotor. Furthermore, indicated horsepower is proportional to the mean effective pressure, so that an increase in mean effective pressure increases the indicated horsepower produced by the engine.

There are many references that disclose rotary engines that teach different types of combustion chambers, which for a rotary engine to operate must change in volume so that the compression and expansion phases may occur. These references include U.S. Patent No. 3,221,715 (Romoli) which accomplishes combustion chamber volume change by complementary configuration of an engine's housing with a single rotor to which a drive shaft is directly affixed. Cavities formed in the inner walls of the engine housing in combination with the outer walls of an elliptical rotor define chambers that change in volume as the rotor spins. Eells in

U.S. Patent No. 3,782,341 and Hariman in U.S. Patent No. 3,750,630 disclose other ways to change volume in combustion chambers during the compression and expansion phases so that the engine may function efficiently.

Schonholzer in U.S. Patent No. 4,788,952 discloses a rotary engine having a cylindrical housing and a two piece rotor. The combustion chambers in the engine are defined by the gaps at either end of a cutout portion of the rotor between the walls of the cutout portion and the walls of the cylinder.

None of the above references, however, teaches a variable compression ratio engine. Consequently, there remains a need for an efficient, lightweight and compact engine in which the compression ratio of the engine can be varied so that the effective output of the engine can be modified.

SUMMARY OF THE INVENTION

According to its major aspects and broadly stated, the present invention is an internal combustion rotary engine that is connected to a drive shaft by a double gimbal. The gimbal, acting through two rotors, causes the size of the combustion chambers in the engine to vary from smaller to larger to smaller and back to larger as they move through a complete cycle. The engine is designed so that, during operation, the compression ratio of the engine may be changed by pivoting the engine slightly with respect to the drive shaft, so that the two are set at a new angle. The gimbal causes this change in angle to alter the compression ratio of the engine in a manner that will be explained in detail herein. The engine can be constructed as an external or internal combustion engine and does not require a valve system, although it does have four strokes in each cycle and four cycles per revolution. The engine comprises a cylindrical housing holding a first rotor and an adjacent, coaxial second rotor. Each rotor has a pair of opposing spokes that extend radially therefrom. The spokes of each rotor also extend axially over the other rotor to occupy a fixed angular portion that runs the full axial width of the housing. This angular portion is defined as angle Y . The spacing between spokes, together with the inner surface of the housing and the rotors, define the combustion chambers. Since there are four spokes, two per rotor, there are four chambers. These are denoted β, ,,..

The first rotor is mounted to a first shaft; the second rotor is mounted to a second shaft. The second shaft is hollow and holds the first shaft within it so that the first shaft is free to rotate inside the second about a common axis. Both the first and second shafts extend through a hole in one end of the housing. As the spokes revolve about their axis, their relative angular speeds oscillate about a certain speed, with the speed of one pair of spokes 90° out of phase with the speed of the other pair. Therefore, the chambers between any two adjacent spokes will also oscillate about an average size from a larger to a smaller size. If the size of the engine chambers can cycle back and forth between smaller and larger as it travels about the housing, an Otto cycle can take place, with combustion and intake occurring when the chambers reach their minimum, and exhaustion and compression taking place after the chambers reach their maximum.

A double gimbal is connected to the two shafts where they exit the housing. The gimbal joins the two shafts to the engine's output shaft. When the rotors rotate, the output shaft rotates with them and, because of action of the gimbal, will rotate regardless of the angle between the rotor housing and the output shaft. The double gimbal combines the rotational motion of the two oscillating shafts into one, constant rotational speed of the output shaft.

Furthermore, because the relative orientation of the rotors can be changed by pivoting the engine with respect to the drive shaft, the variation in the maximum and minimum sizes of the chambers is related to the angle δ between engine and drive shaft. As the angle is increased, the chambers' size range increases; that is, the smallest size becomes even smaller and the largest size of a chamber becomes larger. Therefore, the greater the angle between engine and drive shaft, the higher the compression ratio.

The engine in a preferred embodiment of the present invention will serve as an engine for an automobile. The engine would be mounted to the chassis of the automobile, and the drive shaft would be coupled to a typical transmission system. A pressure sensor would be mounted to the manifold so that the intake pressure of the fuel-air mixture could be monitored. When a decrease in pressure is sensed, the engine housing can be pivoted to increase the angle δ. Other situations may present themselves in which the angle δ would need to be changed, and any number of sensing devices could be used to monitor this possibility. Furthermore, there are numerous possible ways to pivot the engine housing, including a hydraulic cylinder. It should be noted that only small degrees (<5°) of change would be required of angle δ, in order to correct the engine's performance.

It is possible that the engine in an automobile could be used in a spark ignition type engine or possibly a diesel engine. In a diesel engine, the spark plug could be replaced by an injector to inject the fuel into the combustion chamber, and the angle δ increased to increase the compression ratio to a suitable level.

The present engine could be used as a hydraulic engine or a pump. As a hydraulic engine or a pump, two entrances and two exits are provided. In the application as a hydraulic engine, a pressurized fluid, either liquid or gas, is injected into the entrances to force the chamber then at the entrance to expand. This expansion results in the rotation of the first and second rotors and the subsequent rotation of the drive shaft. The hydraulic fluid will produce the rotational mechanical energy to rotate the drive shaft and provides an engine with a constant input flow rate that has a variable RPM output merely by changing the value of angle δ.

As a compressor or hydraulic pump, the drive shaft is rotated by any suitable means, and a supply of fluid is provided at both entrances. The expansion process sucks the fluid into the next chamber and, as the chamber "rotates" over to the exit, the fluid is compressed, forcing it out the exit. Therefore, the pump will provide a variable flow rate and pressure while maintaining a constant input RPM, by merely changing the compression ratio of the apparatus through the value of angle δ.

To function properly and efficiently, there will need to be spark plugs and electrical cables to deliver the voltage for a spark or injectors, a source of a fuel/air mixture, a cooling system, seals, and bearings. These are deemed to be well known by those skilled in the art of engine technology.

A major advantage of the present invention is that the compression ratio of the engine can be modified or changed at any time, including during operation. This feature is simply the result of a slight change in the angle between the engine and the drive shaft, which varies the range in size of the spacings between spokes and thus the combustion chamber size. Another important advantage of the present invention is its simplicity. It has few parts and very few moving parts. This means that the engine is able to provide a higher power-to-weight ratio ~ on the order of twice as powerful — as a typical internal combustion engine. Yet another feature of the present invention is that there is no need for a weight to balance the parts of the present invention, because they are symmetric about the axis of rotation. Furthermore, the principal moving parts of the engine follow a circular path.

Still another feature of the present invention is that the engine can operate without a typical valve system. The removal of this standard equipment not only reduces the weight of the engine, but also removes a part that is subject to wear and tear and requires periodic adjustment.

Another feature of the present invention is that it has four internal rotating volumes that increase and decrease to the maximum and minimum twice during each revolution. Additionally, a single spark plug or injector and combustion chamber, in a diesel-type engine, is all that is required as each maximum and minimum occur at a fixed point relative to the housing.

Other features and advantages of the present invention will be apparent to those skilled in the art from a careful reading of the Detailed Description of a Preferred Embodiment presented below and accompanied by the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

Fig. 1 is a side view of an automobile with an internal combustion rotary engine with a gimbal used as the automobile's engine according to a preferred embodiment of the present invention; Fig. 2 is a perspective view of an internal combustion engine and gimbal according to a preferred embodiment of the present invention, with the drive shaft inclined at an angle;

Fig. 3 is a side view of an internal combustion engine and gimbal according to a preferred embodiment of the present invention, with the drive shaft inclined at an angle;

Fig. 4 is a cross-sectional view of an internal combustion engine according to a preferred embodiment of the present invention;

Fig. 5 is a cross sectional view of a gimbal according to a preferred embodiment of the present invention;

Fig. 6 is an exploded view of the internal combustion engine and gimbal according to a preferred embodiment of the present invention;

Figs. 7A and 7B are perspective views of the internal combustion engine and gimbal according to a preferred embodiment of the present invention, with the shaft inclined at the same angle in both figures, but Fig. 7B showing the shaft rotated 45° from that shown in Fig. 7 A;

Figs. 8A and 8B are perspective views of the internal combustion engine and gimbal according to a preferred embodiment of the present invention, with the shaft inclined at the same larger angle in both figures, but Fig. 8B showing the shaft rotated 45° from that shown in Fig. 8A;

Fig. 9A and 9B are schematic views of an internal combustion rotary engine showing its angular relationships according to a preferred embodiment of the present invention;

Figs. 10A and 10B are schematic views of an internal combustion rotary engine showing the internal processes of a typical spark-ignition type engine according to a preferred embodiment of the present invention;

Fig. 11 is a schematic view of an internal combustion rotary engine showing the internal processes of a typical diesel combustion ignition type engine according to a preferred embodiment of the present invention; and Fig. 12 is a schematic view of this machine being used in an application as a pump or hydraulic engine according to a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

In the following description, similar components are identified by the same reference numerals in order to simplify the understanding of the sequential aspect of the drawings. The present invention is an internal combustion engine of the type that may be used for an automobile, for example. Fig. 1 illustrates an automobile 10 having an engine 12 coupled via a transmission 14 to a drive shaft 16. Drive shaft 16 is connected to rear wheels 18 via a differential 20. A carburetor 28 is connected to engine 12 as an intake device, thus regulating the fuel and air mixture. An exhaust pipe 38 extends from engine 12 to exhaust waste gases produced during combustion within engine 12. Engine 12 is mounted at an angle δ with respect to drive shaft 16, and that angle can be increased to increase the compression ration of engine 12 by, for example, a hydraulic cylinder 22. Compression ratio can be decreased or increased by decreasing or increasing angle δ, respectively.

The arrangement of drive train components illustrated in Fig. 1 is conventional, except for the use of the present engine 12 and hydraulic cylinder 22 to rotate it. Other arrangements, including front wheel drive, are also possible.

The operation of engine 12 will be explained in detail presently. However, as an overview, engine 12 operates as follows: the combustion of a fuel air mixture in the chambers of the engine 12 causes two spoked rotors to revolve about a common axis within the engine housing. The sides of the spokes and the interior of housing define four combustion chambers. These spokes are arranged in two pairs, and each pair is connected to a shaft. The two shafts do not rotate at a constant rate but, rather, oscillate about a constant rate. Each pair of spokes oscillates 90° out of phase with respect to the other, with the amplitude of the oscillations being related to the compression of the engine. The double gimbal combines the oscillating rotational motion of the two rotors into a constant rotational motion of drive shaft 16. The rotation of drive shaft 16, geared down by transmission 14, propels automobile 10. Referring now to Figs. 2-6, there is illustrated a preferred embodiment of a combustion engine according to the present invention. Combustion engine, generally indicated by reference numeral 30, includes an engine block 32, a double gimbal 34 and an output shaft 36. Engine block 32 includes a cylindrical housing 40 having a first rotor 42, a second rotor 44, a first shaft 46 and a second shaft 48. First rotor 42 has two spokes 50; second rotor 44 also has two spokes 52. Spokes 50 and 52 extend both radially outward from the axis of rotation of rotors 42 and 44, respectively, and axially to both endwalls 54, 56, of housing 40, so that, when properly oriented and placed in adjacent, coaxial relationship, spokes 50, 52 of rotors 42, 44, respectively, interleave. Spaces are defined by the sides of adjacent spokes 50, 52, housing 40, rotors 42, 44 and endwalls 54 and 56. These spaces define combustion chambers 60, 62, 64, and 66. (See Figs. 7A and B, and 8A and B.) As will be explained presently, when spokes 50, 52 revolve about their axes 58, chambers 60, 62, 64, and 66 also "rotate," or appear to rotate as spokes 50, 52 rotate, and, moreover, to change in size as they rotate from smaller to larger and back to smaller and then finally larger in one complete revolution.

First rotor 42 is attached to first shaft 46, and second rotor 44 is attached to second shaft 48. Second shaft 48 is hollow and dimensioned internally so that first shaft 46 fits inside second shaft 48. First shaft 46 rotates easily within second shaft 48 and about common axis 58 of rotation. Shafts 46, 48 are journaled in bearings 68 to rotate easily in housing 40. First and second shafts 46, 48 exit through a hole 70 (Fig. 5) in endwall 54, where they are connected to double gimbal 34. Double gimbal 34 is comprised on a first outer fork 72, a first inner fork 74, a ring 76, a disk 78, and a second fork 80. Second fork 80 is attached to output shaft 36. The rotational motion of first and second shafts 46, 48 is coupled to output shaft 36 by gimbal 34, so that the average rotational speed of first and second shafts 46, 48, is the speed of output shaft 36.

Second shaft 48 is connected to the center of first outer fork 72, which has two arms 90 extending radially from the center of first outer fork 72. Between arms 90 of first outer fork 72 is mounted ring 76, pivotally attached to arms 90 so that it rotates about an axis 92 running from one arm 90 to the other. Second fork 80 has four arms, two outer arms 94 which are attached to ring 76, and two inner arms 96, all four of which extend radially from the center of second fork 80. Outer arms 94 of second fork 80 are also pivotally attached to ring 76. The point of attachment of arms 94 of second fork 80 is displaced 90° from where arms 90 are connected to ring 76. Second fork 80 pivots with respect to ring 76 about an axis 98 running from one outer arm 94 of second fork 80 to the other. Axis 98 is always perpendicular to axis 92.

First inner fork 74, which is attached to first shaft 46, also has two radially extending arms 100. Arms 100 are pivotally attached to disk 78 so that disk 78 can pivot inside of ring 76 and about an axis 102 that runs from one arm 100 to the other. Inner arms 96 of second fork 80 are also pivotally attached to disk 78, and their point of attachment is 90° displaced from arms 100. Inner arms 96 pivot about an axis 104 that is always perpendicular to axis 102.

It will be clear that as spokes 50 and 52 rotate, so will rotors 46 and 48, first outer and inner forks 72 and 74, ring and disk 76 and 78, and second fork 80 and output shaft 36. If output shaft 36 is moved so that its axis is aligned with axis 58, the relationships among these components of gimbal 34 will remain fixed as they rotate. However, when the axes of combustion engine 30 and output shaft 36 are set at an angle with respect to each other, ring 76 and disk 78 will "wobble" as spokes 50, 52 are rotated and the angular distance between them oscillates. Specifically, the planes defined by ring 76 and disk 78 will oscillate, when viewed from the rotating output shaft 36, ring 76 and disk 78 pivoting about axes 92 and 102, respectively, and about a position where the planes are perpendicular to an axis 106 of output shaft 36. The amplitude of this oscillation is related to the angle δ between axis 106 and axis 58: the greater this angle δ, the larger the magnitude of the oscillations. The neutral point of oscillating ring 76 — where a line perpendicular to the plane of ring 76 is aligned with output shaft 36 — is 90° out of phase with the neutral point of disk 78. Finally, the neutral point is reached twice in each 360° rotation of output shaft 36.

This oscillation of ring 76 and disk 78 is directly related to an oscillation in the rates of rotation of first shaft 46 and second shaft 48 with respect to the rate of rotation of output shaft 36. Both will rotate faster, then slower, then faster, and then slower again, than the rate of rotation of output shaft 36, with first shaft 46 being out of phase of second shaft 48 by 90°. Because spokes 50 and 52 are attached to first and second rotors 42 and 44, which are, in turn, attached to first and second shafts 46 and 48, respectively, the resulting motion is also oscillatory. More specifically, this motion can be described as a speeding up of a spoke, followed by a slowing down of a spoke, and then a speeding up again, and finally a slowing down, as each spoke makes a complete revolution about its shaft. Because adjacent spokes 50, 52 are out of phase, each chamber 60, 62, 64, 66 will appear to get smaller as a "speeding up" trailing spoke catches up to the "slowing down" spoke ahead of it. Then the chamber will expand as the leading spoke accelerates and the trailing spoke slows down. In one revolution of output shaft 36, each chamber 60, 62, 64, 66 will expand twice and contract twice. The amplitude of the size of each chamber in making one revolution is related to the angle δ between axis 58 and axis 106.

This relationship is illustrated by comparing Figs. 7 A to 7B, and Figs. 8 A to 8B. Figs. 7 A and 7B show output shaft 36 at the same angle δ, but rotated 45° from one figure to the other. Note that the sizes of chambers 60 and 64 are smaller, and chambers 62 and 66 are larger in Fig. 7A compared to 7B. In Figs. 8 A and 8B, the angle δ' of output shaft 36 is again held the same for both figures, but is larger than that shown in Figs. 7 A and 7B. Again, output shaft 36 is rotated 45° from one figure to the other; and again chambers 60 and 64 are larger and chambers 62 and 66 smaller in Fig 8B compared to Fig. 8A; however, chambers 60 and 64 are even larger, and chambers 62 and 66 are even smaller in Figs. 8 A and 8B than in 7 A and 7B. During the next 45° rotation of output shaft 36, the relationship of chambers 60, 62, 64, and 66 will return to that shown in Figs. 7A and 8A; however chamber 60 and 64 will be interchanged with chamber 62 and 66. This change in size of chambers 60, 62, 64, 66 as spokes 50 and 52 revolve around axis 58 can be effected by the four steps of an Otto cycle: intake, compression, power (combustion) and exhaust. When a chamber is expanding, it can take in a fuel air mixture. When it grows smaller, it can compress the mixture to the point where the mixture can ignite spontaneously, as in a diesel engine or by means of a spark plug. After ignition, the combusting mixture can drive the expanding chamber. The shrinking of the chamber following combustion can push the exhaust gases from combustion engine 30. Referring to Fig. 9A and 9B, between each pair of spokes 112 defines an internal rotating chamber 114, 116, 118, 120 that has a volume that is determined in part by the magnitude of the radial angle Y of the spokes 112, as well as other structures of the combustion engine, as indicated above. During the engine processes: intake, compression, combustion/expansion, and exhaust, these chambers 114, 116, 118, 120 experience changes in their volume. The relative volume these chambers occupy is defined by the angles β. i > ,, and during one complete revolution, each of these angles reaches a maximum, βmax , and a minimum, βmm. The maxima and minima for the chambers are equal, and the position at which they occur is fixed relative to the position of housing 122.

As shown in Figs. 10A and 10B, only a single spark plug, entry, and exit are provided for the engine, because each engine process occurs at a fixed point relative to housing 122, only one of each is required. As chamber 116 compresses the air- fuel mixture and passes the spark-plug, the fuel-air mixture contained within is ignited, thus causing the mixture to burn and, therefore, forcing chamber 116 to expand. Chamber 118 is expanding in response to the burning of an fuel-air mixture, and chamber 120 is exhausting waste gases. Chamber 114, expanding over the intake, draws in a new supply of fuel-air mixture. One of chambers 114, 116, 118, 120 compresses a supply of fuel-air mixture prior to its being ignited by a spark plug. The other chamber is positioned over the exit to exhaust the waste gases that result from the combustion process. Each chamber performs all of these functions once during a complete revolution of output shaft 36. During the intake and exhaust processes, the fuel-air mixture and the waste gases flow to and from the chambers in an approximately continuous stream.

The angle between axis 58 and axis 106, generally designated as Angle δ and Angle δ' in Figs. 7A and 7B, 8A and 8B, can be labeled angle δ. The value of angles β, _ » , change in relation to the rotating of output shaft 36 and the respective values of β m x and βmm change with respect to a change in angle δ. When engine 30 is rotating, the angular velocities of first rotor 42 and second rotor 44 vary with respect to each other. Furthermore, the angular velocity of either first rotor 42, second rotor 44, or output shaft 36 can be determined through the other two angular velocities, the angle δ, and the relative angular position of output shaft 36 with respect to the origination of the movement of output shaft 36. Furthermore, the ratio of the values of βm and βmm represent the compression ratio of the engine, and an increase in the angle δ will increase the compression ratio, while a decrease in the angle δ will cause the compression ratio to decrease until angle δ=0, when the compression ratio is equal to one.

Output shaft 36 rotates relative to first shaft 46 and second shaft 48, and during one complete revolution of output shaft 36, first shaft 46 and second shaft 48 complete one revolution. While Θ defines the angular position of drive shaft 36, φi defines the angular position of first rotor 42, and φ2 defines the angular position of second rotor 44. The relationship of φi and φ2 with respect to angle δ and angle Θ are illustrated in the following equations:

φi = arctan(tanΘcosδ)

φ2 = arccot(cotΘcosδ) The spaces between spokes 112 and their adjacent spokes 112 define chambers 114, 116, 118 and 120. First, second, third, and fourth chambers 114, 116, 118, 120 are independent of each other and are bound between their respective spokes, housing, rotors and end walls. As best seen in Fig. 9B, the radial angle which spokes 112 occupy is defined by angle Y , and angles β> ..... are proportional to the volume that chambers 114, 116, 118, 120 occupy. The value of angle Y is fixed. A typical value for this angle is

65° or approximately radians.

36

During one complete revolution of the shafts 46, 48, the volume of chambers 114, 116, 118 and 120, designated as β max for the maximum and β in for the minimum, reach each maximum and minimum twice. During the revolution of first rotor 42 and second rotor 44, the volume of chambers 114, 116, 118 and 120 expands and compresses until the maximum and minimum are reached twice. Maxima and minima of angles βι.ι.j. for each chamber are all equal, and the position of the minima and maxima are fixed relative to the positions of first rotor 42 and second rotor 44. Therefore, the expansion and contraction of these chambers start from a fixed point relative to first rotor 42's and second rotor 44' s position and housing 122, and end in another fixed point. Variations in the β m x and βmin are readily possible with respect to the changes in angle δ .

If angle β is designated in a general situation, angle β is defined by the following equation:

β = γ + arctan(tanΘcosδ)- arccot(cotΘcosδ)

The angle δ is the angle that can be changed during the operation of internal combustion rotary engine 110. By changing this angle, the values of β m x and βmin are changed. Therefore, when angle Θ = Kπ +— , β is

3π minimum, and when angle Θ = Kπ H , β will become maximum (K is

4 an integer). The following equations show this relationship:

β m = — γ + arctan(cosδ) - arccot(cosδ)

β m = — γ + arc cot(cos δ) - arctan (cos δ)

When the angular velocity of first shaft 46 is defined as oi , the angular velocity of second shaft 48 is defined as α>2, and the angular velocity of output shaft 36 is defined as (1)3, a single angular velocity of either first shaft 46, second shaft 48, or output shaft 36 is the function of angle δ , angle Θ (the position of angular rotation of output shaft 36 relative to the origin of angular measurements), and the other two angular velocities, then the following equation represents the differences in angular velocities of first rotor 42 and second rotor 44.

(D3Cθsδsin² δ(sin² Θ - cos² Θj ωι - CD2 =

1 - sin² δ + sin⁴ δsin² Θcos² Θ

Within chambers 114, 116, 118, 120, the processes of an internal combustion rotary engine take place. In Figs. 10A and 10B with an entry 132 and an exit 134 shown, intake occurs within chamber 114, compression occurs within chamber 116, combustion and expansion occur within chamber 118, and exhaust occurs within chamber 120. Internal combustion rotary engine 110 with gimbal 34 (Fig. 2) does not require a valve svstftm. althonph it has four strokp.ς in each cvr.le and four nnv r strokes per revolution. Entry 132 supplies a fuel-air mixture in an approximately continuous fashion, while exit 134 functions to remove exhaust that was created during the combustion process in an approximately continuous fashion. Those skilled in the art will recognize that certain fuel-air mixtures will perform better than others, and that certain type exhaust systems will function better to relieve internal combustion rotary engine 110 of its exhaust gases.

As stated earlier, in one complete revolution of output shaft 36 (Fig. 2), angles β, . -.., will have two maximum and minimum values, which create the possibility of omitting the valve system in the application of internal combustion rotary engine 110 as a four stroke- four cycle engine. The maximum and minimum of the angle β. ₂ , 4 in each of chambers 114,

116, 118, 120 are all equal, and the position of the minima and maxima are fixed relative to first rotor 42's and second rotor 44's position (Fig. 6). Therefore, the expansion and compression of chambers 114, 116, 118, 120 start from a fixed point relative to the positions of first and second rotor 42, 44 (Fig. 6), and housing 122, and end in another fixed point. Since each intake, compression, expansion, and exhaust step occurs at a fixed position relative to housing 122, entry 132 and exit 134 may all be located in a fixed position.

As stated above, when angle β..₅ of chambers 114, 118 are at a maximum, angle β₂.4 of chambers 116, 120 are at a minimum. Variations in βmax and βmm are readily possible with respect to changes in the angle δ . The angle δ can be changed while internal combustion rotary engine 110 is in operation and angle δ is selected such that, by considering βma and βmin and the shape of the surfaces creating chambers 114, 116, 118, 120, the compression and expansion ratio in different applications of internal combustion rotary engine 110 is modified to produce a desired value. An example of typical βm x and βmm values and their respective compression ratio follow:

K 13κ Where δ=— or 45° and γ= or 65°.

4 ' 36

βmin = — - γ + arctan(cosδ) - arccot(cosδ)

7C Tt β mm = — γ + arctan(cosδ) \- arctan(cosδ) β mm = 2 arctan(cosδ) - γ

βmax = γ + arccot(cosδ) - arctan(cosδ)

βm x = γ -ι arctan(cosδ) - arctan(cosδ) βmax = π - γ - 2 arctan(cosδ) thus, where *^* is the compression ratio, the value is as follows:

If the angle δ is changed to .829 radians or 47.5° and angle

13π γremains or 65°, the values of βmax and βmm and *^*k are as follows:

36

β mm = — γ + arctan(cosδ) - arc cot(cosδ)

βmin = — γ + arctan(cosδ) — + arctan(cosδ) βmin = 2arctan(cosδ) - γ β mm =.05385 = 3.085° βmax = — γ + arccot(cosδ) - arctan(cosδ)

βmaχ = — γ -i arctan(cosδ) - arctan(cosδ)

βm x = π - γ - 2arctan(cosδ)

thus, where *^"k is the compression ratio is as follows:

It can be seen from the above examples that small changes in angle δ can vary the compression ratio at which internal combustion rotary engine 110 is operating.

In engine 12, a valve system is not required, and typically, a fuel-air mixture flows in and the exhaust flows out of chambers 114, 116, 118, 120 approximately continuously. A spark plug 140, as shown in Figs. 10A and 10B, is used to ignite a fuel-air mixture as it passes spark plug 140. Other methods of igniting the fuel-air mixture in a spark-ignition engine are possible and known to those skilled in the art, and thus, these modifications are within the scope of this disclosure.

In a diesel type internal combustion rotary engine 142 as shown in Fig. 11, spark plug 140 is replaced by an injector 144 and a combustion chamber 146. The compression ratio for a diesel engine operating under a compression ignition system will typically be higher than that of a spark ignition system. The replacement of these elements and a modification to angle δ will typically allow the spark-ignition internal combustion rotary engine 110 to be converted to a diesel type internal combustion rotary engine 142. Those skilled in the art will recognize that certain other modifications can be made to a diesel type internal combustion rotary engine 142, so that it may function and perform better.

As noted from the above equations and calculations, the angle δ would only need to be modified by small degree changes in order to adjust the compression ratio. In the application of internal combustion rotary engine 110 as part of automobile 10 (Fig. 1), the angle δ would likely only be changed by a modification of less than 5°. Changing the value of δ is only needed to increase engine efficiency, which will result in a decrease in fuel consumption. It is contemplated that an increase in the δ angle would be required in a variety of situations, including when internal combustion rotary engine 110 is operating at a high altitude or when there is a manifold pressure decrease (for example, when the gas throttle is not completely open). If these situations were reversed, then a decrease in angle δ would be necessary to modify internal combustion engine 110's performance.

It is also contemplated that in a preferred embodiment of internal combustion rotary engine 12 (Fig. 1), a change in angle δ would be dictated by a pressure sensor 24. Pressure sensor 24 is mounted in the wall of a manifold 26 and senses the intake fuel-air mixture and communicates with cylinder 22 to change angle δ by pivoting internal combustion rotary engine 12. Cylinder 22 could alternatively be a mechanical or electro¬ mechanical device or the like, as are known to those skilled in the art. Furthermore, those skilled in the art will recognize that modifications to pressure sensor 24 can be made or that other certain measurements could be used to adjust the compression ratio of internal combustion rotary engine 12, all of which are contemplated by this disclosure.

As stated above, engine efficiency and output power is generally related to compression ratio (assuming intake air-fuel mixture volume and pressure are constant). The following equations indicate that an increase in compression ratio will result in increased engine efficiency and decreased fuel consumption:

Assume the following conditions: an ideal Otto engine with 20 lbs./min. of air, initially at 14 psia and 120°F; the engine uses r =.0556 lb. fuel lb. air with a lower heating value of q_t=l 9,000 Btu/lb. fuel.

Assume Tk = = 7.67, then

V₂

_v^ ωRT 20)(53.3)(580) _{= 307cfm} p, (14)(144)

VD = V. - V2 = VI - — = 307 - — = 267cfm a 7.67 for Tι=580°R, we get the following from the values: pn = 1.7800, μι = 98.90, υπ = 120.70, φl =.61793. then,

Now corresponding to υ_r 2:

T₂=1274°R, p_r2 = 30.02, μ₂ = 222.91—, h₂ = 310.25 ^btU lb lb

Btu

QA = Rnaq, = (.0556)(19000) = 1056 lb. air

This energy goes solely toward increasing the molecular internal energy during the constant volume combustion, thus neglecting the fuel and change of working substance,

Q_A = μ₃ - μ₂ or μ₃ = μ2 + Q_A = 222.91 + 1056 = 1278.91— lb

Now corresponding to μ3:

T3=5950°r, Dr3 = 19371, h₃ = 1686.8—, υ_r3 =.11379. ' lb

υr4 = (υr3)(Λ) = (.11379X7.67) =.8728 orresponding to I :

T4 = 3

Therefore, the heat rejected is:

Btu

Q_R = μ4-μ. = 650.1 -98.9 = 551.2 lb.

W=QA-QR = 1056 -551.2 =

The amount of horse power produced is: (504.8X20) ₌ 42.4 and the efficiency is:

which provides the MEP (mean effective pressure) and converting

_MEp

Now assume Tk = then

_Vι=ωRTι ₌ (20X53.3X580) _=307cfm

P' (14)(144)

VD = V.-V₂ = V₁- = 276.3cfm for Tι=580°R, we get the following from the values: pn = 1.7800, μι = 98.90, υn = 120.70, φl =.61793. then,

Now corresponding to υ_r2 :

T₂=1

Btu

QA = Rfiaq, = (.0556 )( 19000) = 1056 lb. air

Btu

Q_A = μ₃ - μ₂ or μ₃ = μ₂ + Q_A = 246.13 + 1056 = 1302 lb Now corresponding to μ3: btu

T3=6034°r, p_r3 = 20722, h₃ = 1712.9 — , υ_r3 =.10864. ^v lb

υr4 = (υ_r3)(r ) = (.10864)(10) = 1.0864 Now corresponding to υ_r4 :

T4 = 3100°R, pr4 = 1118.98, h₄ = 820.22— , μ₄ = 607.7— lb ^ lb.

Therefore, the heat rejected is

Btu

QR = μ₄ - μi = 607.7 - 98.9 = 508.8 lb.

Btu

W = QA - QR = 1056 - 508.8 = 547.2 lb.

The amount of horse power produced is: (547.2)(20) hp = = 258.1

42.4 and the efficiency is:

which provides the MEP (mean effective pressure) and converting to psi. MEP si

From the above equations, it can be seen that with an increase in compression ratio, the horsepower, efficiency, and MEP increase. Thus, with internal combustion rotary engine 30 and gimbal 34 (Fig. 2), the value of the above equations can be changed during the operation of internal combustion rotary engine 30.

In its application as internal combustion rotary engine 30 with gimbal 34, many features that would make a typical internal combustion engine would also be necessary. For example, it would be necessary to provide seals within housing 40, provide a means for lubricating surfaces that experience friction, and provide a means for cooling internal combustion rotary engine. However, those skilled in the art will recognize these requirements and be able to provide the necessary combination of elements so that internal combustion rotary engine 30 with gimbal 34 will function and operate properly. Each of the above parts, including but not limited to first rotor 42, second rotor 44, housing 40, and gimbal 34, can be constructed from a variety of materials known to those skilled in the art of engine manufacture. Ideally, the selection of materials would be such that internal combustion rotary engine 30 would have a high power to weight ratio and have a long life expectancy.

In an alternative embodiment shown in Fig. 12, internal combustion rotary engine 150 can be modified to function as a pump or a hydraulic or pneumatic engine. In each application, a first entrance 152 and a second entrance 154 and a first exit 156 and a second exit 158 are provided. In the pump application, the drive shaft (not shown in Fig. 12) is rotated by any means known to those skilled in the art, such as an engine or other mechanical means. As the drive shaft is rotated and angle δ is such that compression and expansion occurs within chambers 160, 162, 164, 166, (δ>0), chamber 160 intakes supply fluid from first entrance 152, and chamber 162 subsequently compresses the fluid, thus forcing it out through first exit 156. At the same time as the above sequence occurs, chamber 164 is intaking a supply fluid from second entrance 154, and chamber 166 is expelling the supply fluid through second exit 158. The manufacturing of a pump according to the above specifications would provide a pump so that at a constant RPM (revolutions per minute), the output of the pump could be modified merely by changing angle δ . As with the application of internal combustion rotary engine 30, the relative angular velocities of first rotor 42 and second rotor 44 vary, depending on their respective position within housing 40 according to the equations listed above. The compression ratio equations will also be valid and will be proportional to the output of supply fluid. In other words, as the compression ratio is increased and the rotational velocity of output shaft 36 is maintained, the output of the supply fluid through first exit 156 and second exit 158 is also increased.

In the application of internal combustion rotary engine 150 as a hydraulic engine, a supply of high pressure fluid, gas, or steam is supplied through first entrance 152 and second entrance 154. The introduction of this fluid will cause chambers 160 and 164 to expand as these chambers pass first entrance 152 and second entrance 154, respectively. The fluid is exhausted through first exit 156 and second exit 158 after the pressure of the fluid has expanded chambers 162 and 168 to their maximum. The advantage of this application is that the fluid under pressure produces the rotational mechanical energy, and with a constant input flow rate, it is possible to have a variable RPM while the unit is in operation, merely by changing angle δ . If we assume that the input flow rate is constant, the angular velocities, ω; and ω₂ of the first rotor and second rotors, respectively, and co;, of the output shaft, are related to the amount of delivered fluid per one revolution of the output shaft. In the application of a hydraulic engine, when angle δ=0 and thus -t^"k =1, no fluid passes through engine 150 and no power is generated. Increasing angle δ , while the rate of flow is held constant, causes an increasing delivered flow, thus causing an increasing output torque and decreasing output velocity. Conversely, when angle δ is decreased, a decrease in delivered flow causes a decrease in output torque but an increase in output velocity. In its application as a pump, when δ=0 and =1, no fluid passes through and no pressure is generated; however, increasing angle δ causes an increase in flow rate and a decrease in maximum generated pressure, when the RPMs of shaft 36 and power consumption is held constant.

It should be noted that in any application the number of spokes or possibly ribs could be changed or modified to produce certain desired results. Modifications of this sort are still within the scope and are contemplated by this disclosure.

It will be apparent to those skilled in the art that many changes and substitutions can be made to the preferred embodiment herein described without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. An engine, comprising:

a housing having a first end and an opposing second end, said second end having a hole formed therein;

a first shaft within said housing and extending through said hole in said second end;

a first rotor in said housing and attached to said first shaft so that said first rotor is rotatable with said first shaft;

a hollow second shaft in said housing and with said first shaft inside said hollow second shaft, said second shaft rotatable freely with respect to said first shaft, said second shaft extending through said hole in said second end of said housing;

a second rotor inside said housing and adjacent said first rotor, said second rotor being attached to said second shaft and rotatable therewith; means carried by said first and said second rotors for defining a plurality of chambers within said housing;

means formed in said housing for receiving a combustible fuel; means formed in said housing for venting combusted fuel;

means carried by said housing for igniting said fuel;

an output shaft; and

means connected to said first and said second shafts for coupling said first and said second shafts to said output shaft.

2. The engine as recited in claim 1, wherein said coupling means is a double gimbal.

3. The engine as recited in claim 1, wherein said first and said second shafts rotate about a first axis, and said output shaft rotates about a second axis, said first and said second axis being positioned at an angle with respect to each other.

4. The engine as recited in claim 1, wherein said first and said second shafts rotate about a first axis, and said output shaft rotates about a second axis, said first and said second axis being positioned at an angle with respect to each other, said engine further comprising means for changing said angle.

5. The engine as recited in claim 1, wherein said defining means further comprises a pair of spokes carried by said first rotor and a pair of spokes carried by said second rotor.

6. The engine as recited in claim 1 , wherein said defining means further comprises a first pair of spokes carried by said first rotor and a second pair of spokes carried by said second rotor, said first and second pairs of spokes extending axially and radially to said housing from said first and second rotors.

7. The engine as recited in claim 1, wherein said defining means further comprises a first pair of spokes carried by said first rotor and a second pair of spokes carried by said second rotor, said first and said second pairs of spokes extending axially and radially to said housing from said first and second rotors, spokes of said first pair of spokes interleaving spokes of said second pair of spokes.

8. An engine, comprising:

a hollow second shaft in said housing and with said first shaft inside said hollow second shaft, said first and said second shafts rotating about a first axis, said second shaft rotatable freely with respect to said first shaft, said second shaft extending through said hole in said second end of said housing;

a second rotor inside said housing and adjacent to said first rotor, said second rotor being attached to said second shaft and rotatable therewith;

means carried by said first and said second rotors for defining a plurality of chambers within said housing;

means carried by said housing for igniting said fuel;

an output shaft, said output shaft having a second axis of rotation; means connected to said first and said second shafts for coupling said shafts to said output shaft; and

means connected to said housing for moving said first axis at an angle with respect to said second axis.

9. The engine as recited in claim 8, further comprising sensor means connected to said receiving means for governing movement of said moving means.

10. The engine as recited in claim 8, wherein said igniting means is a spark plug.

11. The engine as recited in claim 8, wherein said igniting means further comprises:

a combustion chamber formed in said housing; and

a fuel injector positioned in said combustion chamber.

12. The engine as recited in claim 8, wherein said coupling means is a double gimbal.

13. The engine as recited in claim 8, wherein said defining means further comprises a first pair of spokes carried by said first rotor and a second pair of spokes carried by said second rotor.

14. The engine as recited in claim 8, wherein said defining means further comprises a first pair of spokes carried by said first rotor and a second pair of spokes carried by said second rotor, said first and said second pairs of spokes extending axially and radially to said housing from said first and second rotors.

15. An engine, comprising:

a first rotor in said housing and attached to said first shaft so that said first rotor is rotatable with said first shaft; a hollow second shaft in said housing and with said first shaft inside said hollow second shaft, said first and said second shafts rotating about a first axis, said second shaft rotatable freely with respect to said first shaft, said second shaft extending through said hole in said second end of said housing;

a second rotor inside said housing and adjacent said first rotor, said second rotor being attached to said second shaft and rotatable therewith; a first pair of spokes carried by said first rotor, said first pair of spokes extending radially out from said first rotor and axially to said first and said second ends of said housing;

a second pair of spokes carried by said second rotor, said second pair of spokes extending radially out from said second rotor and axially to said first and said second ends of said housing, each spoke of said second pair of spokes interleaving said first pair of spokes;

means carried by said housing for igniting said fuel;

an output shaft, said output shaft having a second axis of rotation; a double gimbal coupling said first and said second shafts to said output shaft; and

16. The engine as recited in claim 15, wherein said double gimbal further comprises:

a first inner fork attached to said first shaft;

a first outer fork attached to said second shaft;

a disk pivotally attached to said first inner fork;

a ring pivotally attached to said first outer fork; and a second fork pivotally attached to said disk and said ring, said second fork attached to said output shaft.

17. The engine as recited in claim 15, further comprising sensor means connected to said receiving means for governing movement of said moving means.

18. The engine as recited in claim 15, wherein said igniting means is a spark plug.

19. The engine as recited in claim 15, wherein said igniting means further comprises:

a combustion chamber formed in said housing; and

a fuel injector positioned in said combustion chamber.

20. A pump, comprising:

a hollow second shaft in said housing and with said first shaft inside said hollow second shaft, said first and said second shafts rotating about a first axis, said second shaft rotatable freely with respect to said first shaft, said second shaft extending through said hole in said second end of said housing; a second rotor inside said housing and adjacent to said first rotor, said second rotor being attached to said second shaft and rotatable therewith;

a first pair of spokes carried by said first rotor, said first pair of spokes extending radially out from said first rotor and axially to said first and said second ends of said housing;

means formed in said housing for receiving a fluid;

means formed in said housing for venting said fluid;