US3701254A

US3701254A - Rotary piston engine

Info

Publication number: US3701254A
Application number: US45840A
Authority: US
Inventors: Oskar Michejda
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-06-12
Filing date: 1970-06-12
Publication date: 1972-10-31
Anticipated expiration: 1989-10-31
Also published as: DE2129059A1; GB1355254A

Abstract

A rotary piston engine in combination with a compressor and a burner for providing combustion by-product gases at high pressure to operate the rotary piston engine. The rotary piston engine is provided with a rotary valve for timing the introduction of the high pressure gas to the engine piston chambers.

Description

United States Patent Michejda [54] ROTARY PISTON ENGINE v [7 21 Inventor: Oskar Michejda, Fort Wayne, Ind.

[73] Assignee: Jadwiga Koltermann, London, En-

gland; a part interest [22] Filed: June 12, 1970 [21] Appl. No.: 45,840

52] u.s.c1. ..60/39.61,418/l96,418/199, 123/827 [511 1111.0. ..F02g 3/00 [58] FieldofSearch ..60/39.6l,39.63,39.6; 123/345, 8.25; 418/196 [5 6] References Cited UNITED STATES PATENTS 1,933,442 10/1933 Maxwell ..123/8.27

1451 Oct.3l, 1972 2,476,397 7/1949 Bary ..60/39.6l X 2,631,428 3/1953 Shames ..60/39.61 X 1,766,519 6/1930 Johnson ..418/196 2,786,332 3/1957 Taverniers ..60/39.61 1,983,216 12/1934 Carter ..418/196 3,274,943 9/ l 966 Berry ..418/196 3,116,666 1/1964 Scott ..418/196 X Primary Examiner-Clarence R. Gordon Attorney-Harness, Dickey & Pierce [57 ABSTRACT A rotary piston engine in combination with a compressor and a burner for providing combustion by-product gases at high pressure to operate the rotary piston engine. The rotary piston engine is provided with a rotary valve for timing the introduction of the high pressure gas to the engine piston chambers.

11 Claims, 8 Drawing Figures PATENTEDucrsw 1972 3.701. 254

sum 3 or a INVENTO 06%47 7 BY g ml a AJL ROTARY PISTON ENGINE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to engines, and more particularly, rotary piston engines.

2. Description of the Prior Art Various engines are known to the art which use three rotating pistons and a central rotor engaging the-body of each piston. More speciflcaly, the pistons are mounted for rotation within a piston chamber and are provided with a projection for sealingly engaging the wall of the chamber. The central rotor is provided with a recess and is geared to the pistons such that the projection on the pistons will be accepted by the recess as the projections rotate into alignment therewith. The piston projection and the engagement of the rotor with the piston body define an expanding chamber portion and a contracting chamber portion within each piston chamber. These engines are generally characterized by several operating deficiencies, for example, the lack of an adequate provision for preventing decompression within the expanding chamber and compression within the contracting chamber thereby wastefully consuming significant amounts of energy. Moreover, the working portion of the rotational cycle of the piston is often quite short so as to require a relatively large engine for a given power output.

Engines using compressors and burners for providing combustion by-product gas in combination with means for extracting mechanical energy from the combustion by-product gases also known. For example, gas turbine engines fall within this category. However, these engines convert the kinetic energy of the combustion byproduct gases into mechanical energy which results in low torque levels at low gas flow velocities, i.e., at low turbine rotational velocities. Furthermore, gas turbine engines require intricate parts with close tolerancesresulting in notoriously high manufacturing costs. In short due to various design and operational cycle deficiencies, the prior art engine designs fall short of.

SUMMARY OFTHE INVENTION The present invention provides a rotary piston engine which receives combustion by-product gases and converts the pressure energy of the combustion byproduct gases into useful mechanical energy. Preferably, the rotary piston engine is used in combination with an air compressor and fuel burner for providing the combustion by-product gases. The engine is advantageously characterized by obtaining a relatively large torque on the output shaft for a large range of engine rotational velocities including relatively low rotational velocities, and moreover, achieves substantially complete combustion of the gas mixture to obtain low emission rates of exhaust elements causing air pollution.

An exemplary rotary piston engine according to the present invention is described which has, as an additional feature, a novel rotary valve and cooperating port system. The rotary valve and port arrangement of the present invention is arranged to prevent compression of the contracting volume in the rotary piston chamber, decompression of the expanding volume, and moreover, achieves these functional advantages using an uncomplicated rotating valve member.

The engine of the present invention uses parts which rotate rather than reciprocate, and therefore, are easy to balance dynamically. Also, a reduction of fuel consumption is achieved as comparedwith the fuel'consumption of conventional reciprocating piston engines since increased times of combustion may be readily incorporated to provide a more complete combustion of a gas mixture, which also results in low rates of pollutant emission. As an additional advantage, fuels without lead or other octane-increasing ingredients may be used since there is no high compression fuel-ignition system utilized. There advantages are achieved with a relatively simple power mechanism with a minimum number of parts, and accordingly, an inexpensive mechanism as compared to the more complicated reciprocating piston engines and the extremely costly gas turbines.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall functional diagram of an exemplary engine system according to this invention;

FIG. 2 is a side cross-sectional view of an exemplary rotary piston engine, suitable for use with the engine system of FIG. 1, having a novel valve and port arrangement;

FIG. 3 is an end cross-sectional view of the rotary piston engine of FIG. 2 taken generally along the lines 33 so as to illustrate the rotary pistons in their operating positions;

FIG. 4 is another end cross-sectional view of the rotary piston engine of FIG. 2 taken generally along the lines 44 so as to illustrate the gear train of the engine;

FIG. 5 is yet another end cross-sectional view of the rotary piston engine of FIG. 2 taken generally along the lines 55 so as to illustrate the rotary valve of the engine;

FIG. 6 is still another'end cross-sectional view of the rotary piston engine of FIG. 2 taken generally along the lines 66 so as to illustrate the ports downstream of the rotary valve of FIG. 5;

FIG. 7 is an end view of the rotary piston engine of FIG. 2 looking in the direction of arrows 7 7 so as to illustrate the inlet port of the engine; and

FIG. 8 is another end view of the rotary piston engine of FIG. 2 looking in the direction of the arrows 88 so as to illustrate the exhaust port and plenum of the engine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, a diagram is shown illustrating an exemplary engine system 10 according to the present invention. The system 10 includes a rotary piston engine 12 having an output shaft for delivering mechanical energy, for example, to the driven wheels of a motor vehicle, and an accessory shaft for driving an air compressor indicated generally at 14. A burner, also indicated generally at 14, receives compressed air from the compressor and fuel from a fuel pump 16 to provide combustion by-product gases at elevated pressure which are delivered to the rotary piston engine 12.

In FIG. 2, an exemplary rotary piston engine 12 is illustrated which is suitable for use with the engine system of FIG. 1. The rotary piston engine 12 has a housing 18 including an inlet opening 20 for receiving combustion by-product gases from the burner and an exhaust or outlet opening 22 for exhausting expended gases from the engine 12. The rotary piston engine 12 further has a main output shaft 24 for rotating the driven wheels of a vehicle or other power-accepting device and an auxiliary shaft 26 for operating, for example, the compressor and the fuel pump of the system 10 with which it is incorporated.

The rotary piston engine 12 and the housing 18 are generally of stacked construction to provide a structure which is inexpensive to build and maintain. More specifically, the housing 18 may include, from left to right, an inlet end plate 28, a valve surround plate 30, a valve port plate 32, a left bearing support plate 34, a left rotary piston seal plate 36, a rotary piston chamber section 38, a right rotary piston seal plate 40, a right bearing support plate 42, a gear train housing 44, an outlet end plate 46, and an exhaust plenum cover 48.

With reference now to FIG. 3, it will be seen that the rotary piston engine 12 has three identical

rotary pistons

50, 52, and 54 mounted for rotation by bearings at each end (as best seen in FIG. 2) such that the axes of rotation are positioned at the apexes of an imaginary equilateral triangle. The rotary pistons 50-54 each consists of a cylindrical body portion and a projecting

portion

56, 58, or 60, respectively, which sealingly engage the wall of the

cylindrical chambers

62, 64, and 66, respectively. The projections 56-60 may be provided with a radially outward biased seal member to effect the seal between the projection and the chamber wall such as is now the practice with Wankel engine rotors. A central drum 68, having a diameter equal to the body diameters of the pistons 50-54, is provided which is also adapted for rotation by bearings at each end as illustrated in FIG. 2. The locations of the rotary pistons 50-54 and the central drum 68 are established to provide sealing engagement between the central drum and the body portions of the rotary pistons 50-54. The central drum 68 is provided with a recess 70 having a configuration generally adapted to individually accept each projection 5660 in cyclic order.

With reference now to FIG. 4, a gear train for the rotary piston engine 12 is illustrated having a central gear 72 affixed to the central drum 68 for rotation therewith and identical

outlying gears

74, 76, and 78 secured to the rotary pistons 50-54, respectively, and engaged with the central gear 72 for rotation therewith. The gears 72-78 are engaged to rotationally time the pistons 50-54 at 120 intervals with respect to the engagement of the respective projections with rotating drum 68. Specifically, if the dead center engagement of the projection 56 with the recess 70 is considered to be a reference point, 120 of additional rotation will occur prior to dead center engagement of the projection 60 with the recess 70, and 240 of additional rotation will occur prior to dead center engagement of the projection 58 with the recess 70.

Referring again to FIG. 2, it can be seen that the central drum 68 has, as an integral part thereof, the main output shaft 24 and the accessory drive shaft 26. Each of the rotary pistons 50-54 is adapted for clockwise rotation whereas the central drum 68 is adapted for counterclockwise rotation. As a consequence of this rotational scheme and the equal diameters of the body portions of the rotary pistons 50-54 and the central drum 68, a non-sliding seal is effected between the central drum 68 and each rotary piston. Consequently, wear of the pistons 50-54 and drum 68 is minimized.

It can be seen in FIG. 3 that each of the rotary pistons 5054 form an annular chamber or volume which is divided into two portions, each being defined by the engagement of the projection with the wall and the contact between the central drum and the rotary piston.

With reference to both FIGS. 2 and 3, a plurality of inlet ports are provided which communicate the rotary piston chamber 66 with an inlet duct 82, which in turn communicates with an inlet plenum 84 at selected times as determined by the rotational position of a rotary valve disc 86. The inlet plenum 84 communicates at all times with the inlet opening 20. In a similar manner, a plurality of inlet ports 88 are provided for the piston chamber 62 and a plurality of inlet ports 90 are provided for the pistonchamber 64. The inlet ports 88 and 90 are communicated with inlet ducts 92 and 94, respectively, which also communicate with the inlet plenum 84 at selected times in accordance with the rotational position of the rotary valve disc 86. With reference to FIG. 6, it can be seen that the inlet ducts 82, 92, and 94 have openings which are radially equidistant from the axis of the central drum 68 and are spaced at rotational intervals of 120". Also, with reference to FIGS. 2 and 3, a plurality of exhaust ports 96 are provided for the rotary piston chamber 64 communicating with an exhaust duct 98 which at all times communicates with the exhaust opening 22. In similar manner, exhaust ports I00 and 102 are provided for chambers 62 and 66, respectively, which communicate with

exhaust ducts

104 and 106, respectively. The exhaust ducts I04 and 106 communicate at all times with the exhaust opening 22 through an exhaust plenum within the cover 48 as can be best seen in FIG. 8. As can be seen in the drawings, the inlet ports 80, 88 and 90 and the exhaust ports 96, and 102 are located on opposite sides of the contact between the central drum 68 and the respective pistons and are located in close proximity thereto for purposes to be explained hereinafter. Preferably, the rotational interval from the inlet ports to the exhaust ports should be as large as possible, for example, at least 180, and preferably, approximately 270.

The rotary valve 86 is secured to a shaft 108 which is integral with the auxiliary output shaft 26 and the central drum 68 for rotation therewith. As can be best seen in FIG. 5, the valve disc 86 has an arcuate opening 110 extending so as to subtend an arc of nearly which is radially aligned with the openings of inlet ducts 82, 92 and 94. A raised portion or boss 112 surrounds the arcuate opening 1101')" each side of the disc 86. A closed recess portion 113 is provided radially opposite the opening 1 10 so as to facilitate dynamic balancing of the valve disc 86. The boss 112 of the valve disc 86 closely cooperates with the seal plates 28 and 32 on each side thereof so as to effect a substantial fluid seal therebetween. In the position shown in FIG. 5, the valve disc 86 is communicating the inlet plenum 84 with the inlet duct 94 (shown also in FIG. 6) of the rotary piston chamber 64. Accordingly, high pressure gases from the burner will be communicated to the rotary piston chamber 64. Also, in the position shown in FIG. 5, the opening 110 is about to become aligned with the inlet duct 92 for the rotary piston chamber 62. For at least a portion of the operating cycle, both rotary piston chambers 62 and 64 will be receiving high pressure gases from the inlet plenum 84.

As can be seen in the drawings, the rotary piston engine 12 is preferably provided with a plurality of cooling passages 114 which extend through the engine and are adapted to receive a coolant solution for flow therethrough.

In operation, combustion by-product gases at elevated pressures are introduced to the inlet opening 20, and thereafter, are directed in accordance with the position of the rotary valve 86 to one or two of the inlet ports 80, 88, or 90. Referring now to piston chamber 62 of FIG. 3, it can be seen that an annular chamber portion 116, defined by the projection 56 and the engagement of the piston body with the rotary drum 68, receives the combustion by-product gases from the inlet ports 88. The pressure of the gas in the chamber 116 will act upon the rotary piston 50 to cause it to rotate clockwise such that the volume 116 will expand. It can also be seen that an annular chamber portion 118, also defined by the projection 56 and the engagement of the piston body with the rotary drum 68, will contract during the rotation of the rotary piston 50. As the rotary piston 50 rotates, useful torque and power is transmitted to the output shafts 24 and 26 through its associated spur gear 74 and the spur gear 72 of the central drum 68 in substantial accordance with the pressure energy of the gases delivered to the chamber 62. The outlet ports 100, which as previously stated are always open to the exhaust port 22, prevent a pressure rise in the contracting annular chamber portion 118 so as to avoid wasteful expenditure of energy. After a rotation of approximately 180, the passage from the inlet opening 22 to the inlet ports 88 is closed by the valve disc 86. At this time, the elevated pressure gases will force the projection 56 on the rotary piston 50 to move further until, after additional work, it passes the exhaust ports 100 to vent the pressure within the expanding annular chamber portion 116 to atmosphere through the exhaust opening 22. The valve disc maintains the inlet ports 88 closed with respect to the inlet opening as the projection 56 continues in its clockwise movement past the recess 70 until it reaches the trailing edge of the inlet ports 88 at which time the annular slot 110 of the valve disc 86 is again Positioned to provide flow of high pressure gases into the expanding annular chamber portion 116. Similar cycles will take place with respect to the other rotary pistons 52 and 54, only. with an operating lag of 120 and 240", respectively, so as to provide a power output in substantial accordance with the pressure energy of combustion by-prQductgases delivered to

piston chambers

64 and 66, respectively. It will be appreciated that the power outputs of the rotary pistons 50-54 are combined by an engagement of the gears 72-76 with the central gear 78 so as to deliver a combined power output on shafts 24 and 26.

In view of the above description, it now will be appreciated that the present invention provides an engine having high torque and power output over a wide range of rotational velocities. Moreover, it has lower rates of pollutant emission that conventional reciprocating piston engines. The engine of this invention can be constructed at a cost competitive with conventional reciprocating engines. Furthermore, it provides the advantages of a turbine engine in that it uses rotating rather than reciprocating parts, and yet, it does not have the disadvantage of turbine engines of low torque output at low rotational velocities.

While it will be apparent that the teachings herein are well calculated to teach one skilled in the art the method of making the preferred embodiment of this invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or meaning of the subjoined claims.

What is claimed is:

1. An engine system comprising:

a source of fuel;

burner means receiving fuel from said source for combusting said fuel to provide combustion byproduct gas at elevated pressure; and

rotary engine means, including:

housing means having inlet opening means, outlet opening means, and a plurality of generally cylindrical rotary piston chambers with each chamber having a wall; a rotary piston mounted for rotation about an axis within each of said chambers having a cylindrical body and a projection therefrom effecting a substantial gaseous seal with the respective chamber wall, said body forming a substantially annular chamber with said respective chamber wall, said annular chamber being interrupted by said projection, the axis of each of said rotary pistons being in parallel relation each with the other and equidistantly radially disposed from a predetermined central axis;

a rotary seal means engaging each of said cylindrical piston bodies and including a recess for accepting each of said projections, said rotary seal means being adapted for rotation about said central axis in accordance with the rotation of said rotary pistons to provide sequential acceptance of each of said projections on each rotation of said rotary seal means, said rotary seal means and each of said projections defining an expanding annular chamber portion and a contracting annular chamber portion in each of said rotary piston chambers;

inlet port means located in each of said rotary piston chamber walls, each communicating with a respective one of said expanding annular chamber portrons;

outlet port means located in each of said chamber walls, each communicating with a respective one of said contracting annular chamber portions with said housing outlet opening means at least at certain times, each said outlet port means being separated from the respective one of said inlet port means by a predetermined rotational interval; and a rotary valve plate mounted for rotation about said central axis with said rotary seal means having a single opening communicating said housing inlet opening means with each of said inlet port means for at least a portion of each rotational period between adjacent location of respective ones of said projection with the respective ones of said inlet port means and adjacent location of said respective one projection with the respective one of said outlet port means'said housing inlet opening means receiving said combustion by-product gas for rotating said pistons to provide a mechanical power output in substantial accordance with the pressure energy of said gas.

2. An engine system according to claim 1 further including compressor means for providing oxygen containing gas at elevated pressure to said burner means for combustion of said fuel.

3. An engine system according to claim 2 including power transmission means for transmitting power from rotary engine means to said compressor means for operation thereof.

4. An engine system according to claim 3 wherein said power transmission means is a mechanical connection between said rotary piston and said compressor means.

5. An engine system according to claim 1 wherein said rotary valve plate has a generally arcuate opening and an arcuate length providing communication of said combustion by-product gas with said expanding annular chamber portion for a substantial portion of said period.

6. An engine system according to claim 1 wherein said rotary seal means has affixed thereto an output shaft for providing a combined power output of said plurality of rotary pistons.

7. An engine system according to claim 1 having three rotary pistons.

8. A rotary engine comprising:

housing means having inlet opening means, outlet opening means, and a plurality of generally cylindrical rotary piston chambers with each chamber having a wall;

a rotary piston mounted for rotation about an axis within each of said chambers having a cylindrical body and a projection therefrom effecting a substantial gaseous seal with the respective chamber wall, said body forming a substantially annular chamber with said respective chamber wall, said annular chamber being interrupted by said projection, the axis of each of said rotary pistons being in parallel relation each with the other and equidistantly radially disposed from a predetermined central axis;

a rotary seal means engaging each of said cylindrical piston bodies and including a recess for accepting each of said projections, said rotary seal means being adapted for rotation-about said central axis in accordance with the rotation of said rotary pistons to provide sequential acceptance of each of said projections on each rotation of said rotary seal means, said rotary seal means and each of said projections defining an expanding annular chamber portion and a contracting annular chamber portion in each of said rotary piston chambers; inlet port means located in each of said rotary piston chamber walls, each communicating with a respective one of said expanding annular chamber portions;

outlet port means located in each of said chamber walls, each communicatingwith a respective one of said contracting annular chamber portions with said housing outlet opening means at least at certain times, each said outlet port means being separated from the respective one of said inlet port means by a predetermined rotational interval; and

a rotary valve plate mounted for rotation about said central axis with said rotary seal means having a single opening communicating said housing inlet opening means with each of said inlet port means for at least a portion of each rotational period between adjacent location of respective ones of said projection with the respective ones of said inlet port means and adjacent location of said respective one projection with the respective one of said outlet port means such that pressure communicated to said inlet opening will cause pressure responsive rotation of said rotary piston.

9. An engine system according to claim 8 wherein said rotary valve plate has a generally arcuate opening and an arcuate length providing communication of said housing inlet opening means with said expanding annular chamber portion for a substantial portion of said period.

10. An engine system according to claim 8 wherein said rotary seal means has affixed thereto an output shaft for providing a combined power output of said plurality of said rotary pistons.

11. An engine system according to claim 8 having three rotary pistons.

Claims

1. An engine system comprising: a source of fuel; burner means receiving fuel from said source for combusting said fuel to provide combustion by-product gas at elevated pressure; and rotary engine means, including: housing means having inlet opening means, outlet opening means, and a plurality of generally cylindrical rotary piston chambers with each chamber having a wall; a rotary piston mounted for rotation about an axis within each of said chambers having a cylindrical body and a projection therefrom effecting a substantial gaseous seal with the respective chamber wall, said body forming a substantially annular chamber with said respective chamber wall, said annular chamber being interrupted by said projection, the axis of each of said rotary pistons being in parallel relation each with the other and equidistantly radially disposed from a predetermined central axis; a rotary seal means engaging each of said cylindrical piston bodies and including a recess for accepting each of said projections, said rotary seal means being adapted for rotation about said central axis in accordance with the rotation of said rotary pistons to provide sequential acceptance of each of said projections on eAch rotation of said rotary seal means, said rotary seal means and each of said projections defining an expanding annular chamber portion and a contracting annular chamber portion in each of said rotary piston chambers; inlet port means located in each of said rotary piston chamber walls, each communicating with a respective one of said expanding annular chamber portions; outlet port means located in each of said chamber walls, each communicating with a respective one of said contracting annular chamber portions with said housing outlet opening means at least at certain times, each said outlet port means being separated from the respective one of said inlet port means by a predetermined rotational interval; and a rotary valve plate mounted for rotation about said central axis with said rotary seal means having a single opening communicating said housing inlet opening means with each of said inlet port means for at least a portion of each rotational period between adjacent location of respective ones of said projection with the respective ones of said inlet port means and adjacent location of said respective one projection with the respective one of said outlet port means said housing inlet opening means receiving said combustion by-product gas for rotating said pistons to provide a mechanical power output in substantial accordance with the pressure energy of said gas.

7. An engine system according to claim 1 having three rotary pistons.

8. A rotary engine comprising: housing means having inlet opening means, outlet opening means, and a plurality of generally cylindrical rotary piston chambers with each chamber having a wall; a rotary piston mounted for rotation about an axis within each of said chambers having a cylindrical body and a projection therefrom effecting a substantial gaseous seal with the respective chamber wall, said body forming a substantially annular chamber with said respective chamber wall, said annular chamber being interrupted by said projection, the axis of each of said rotary pistons being in parallel relation each with the other and equidistantly radially disposed from a predetermined central axis; a rotary seal means engaging each of said cylindrical piston bodies and including a recess for accepting each of said projections, said rotary seal means being adapted for rotation about said central axis in accordance with the rotation of said rotary pistons to provide sequential acceptance of each of said projections on each rotation of said rotary seal means, said rotary seal means and each of said projections defining an expanding annular chamber portion and a contracting annular chamber portion in each of said rotary piston chambers; inlet port means located in each of said rotary piston chamber walls, each communicating with a respective one of said expanding annular chamber portions; outlet port means located in each of said chamber walls, each communicating with a respective one of said contracting annular chamber portiOns with said housing outlet opening means at least at certain times, each said outlet port means being separated from the respective one of said inlet port means by a predetermined rotational interval; and a rotary valve plate mounted for rotation about said central axis with said rotary seal means having a single opening communicating said housing inlet opening means with each of said inlet port means for at least a portion of each rotational period between adjacent location of respective ones of said projection with the respective ones of said inlet port means and adjacent location of said respective one projection with the respective one of said outlet port means such that pressure communicated to said inlet opening will cause pressure responsive rotation of said rotary piston.

11. An engine system according to claim 8 having three rotary pistons.