The subject of the invention is a pistonless rotary Stirling engine, designed especially for replenishing energy in hybrid and electric motor cars. It can be also used as a small portable panel electric power generator in the areas without access to power supply network, as a panel sun battery or as an industrial system for energy recovery in processes generating large quantities of heat as well as in space stations located either in outer space or on planets.

The commonly known Stirling engine is an external combustion heat engine converting heat energy into mechanical energy with the internal fuel combustion omitted, as the heat is supplied to the engine from external heater, while the source of heat may include combustion of proper fuel, e.g. combustible gas. The source of heat my also include the energy of a exothermic chemical reaction.

In its fundamental design version, the Stirling engine consists of two cylinders— a hot one fed with the heat of an external heater, and the cold one, cooled by mean of an external cooler, wherein the bases of the two cylinders are connected to each other by means of a pipe, wherein the bases of both cylinders are connected with each other by mean of a pipeline, and inside them there is a fixed amount of gas and a slidably mounted piston functioning as a gas displacer.

In one of the cylinders, there is a clearance-fitted slidably mounted piston functioning as a gas displacer, while in the second cylinder, the piston is close-connected there with.

Both pistons are connected by means of their rods with crankshaft in such a way that the piston in the hot cylinder precedes the piston in the cold cylinder by ¼ of the engine's operation cycle. The principle of operation of the engine consist in that first the gas heated in the hot cylinder increases its volume and then it is pressure forced by piston of the cylinder to the cold cylinder where the gas decreases its volume and at a minimum of its volume it is pressure forced by piston of that cylinder to the hot cylinder; then the cycle is repeated.

From publication entitled „Stirling engine" by Stefan Zmudzki, Warszawa 1993, page 168, a Stirling machine is known used for air conditioning and heating in rooms and containing two heat exchangers located in the expansion space with low temperature and in the compression space with high temperature of Stirling engine???. A common working mechanism powers two pistons moving in cylinders with axes inclined at an angle close to 90°, and the spaces over the two pistons are connected by means of a connecting ducts maintaining the same parameters of the working gas in both spaces. The compression space of the piston is connected with the expansion space of the second cylinder through a system of heat exchangers specific for Stirling engine, i.e. a high-temperature heater, regenerator and cooler. Said components enable one piston to perform usable work transmitted to the second piston. As a result of supplying energy from outside to power the Stirling machine in clockwise direction, in the course of expansion of the working gas in the expansion space, the heat transfer from atmosphere occurs in the heat exchanger located therein by means of the circulation medium. Further, during compression of working gas, the heat exchange process occurs in the compression space comprising heat transfer in the heat exchanger to the circulation medium heating a space in question.

The fundamental inconvenience of previously known Stirling engine designs consists in the necessity to provide large heat exchange surface areas and insufficient service life of piston sealing rings, while available piston assembly construction solutions fail to provide a fully effective oil scrapping from the outer piston surface thus deteriorating the engine's effectiveness, and its over-complicated structure results in too high fabrication costs. Moreover, all previous structural designs utilising the general principle of operation of the Stirling engine were limited to proper combination and configuration of the heat exchanger with the displacer piston moving inside thereof, with a piston typical for pneumatic actuators providing power and creating a positive feedback depending on temperature difference existing between the cold and the hot part of the exchanger. This always generates significant technical problems relating to appropriate configuration of shafts, connecting rods, piston operating cycles and issues related to sealing thereof, thus increasing the overall cost of such engine.

The purpose of the present invention consists in development, compared to previously known solutions, of a significantly simpler and compact structure of an all-purpose Stirling engine with enhanced efficiency, comprising no pistons, connecting rods or pneumatic actuators and allowing to transform the supplied thermal energy in any form, including solar energy or energy of combustion of any fuel, into rotational motion of the shaft without the use of expensive piston- crankshaft systems and eliminating the problems relating to piston sealing.

The point of pistonless rotary Stirling engine according to the invention consists in that it is composed of at least one hermetic two-piece

80 cylinder and a rotationally positioned close-fitted profile displacer, or the engine favourably comprises two hermetic two-piece cylinders joined rigidly to each other with clearance-fitted profile displacers located therein and mounted on a common shaft, wherein on one of protruding ends of axle of the profile displacer or on the protruding end

85 of the shaft there is starter mounted as well as rotor of the pneumatic engine, body of which is rigidly connected to the cylinder's front face, and further the parts of cylinder or cylinders containing working gas heated up by a heater connected by means of an air duct with cylindrical portion of the pneumatic engine, while the parts of cylinder

90 or cylinders containing working gas cooled by the cooler are connected via an air channel also with the cylindrical part of the engine. The cylinder or cylinders of the engine comprise preferably two identical parts separated from each other by means of thermal insulation layer. The circuit of the both air channels comprise preferably a pneumatic

95 rectifier comprising four check valves creating preferably a circuit similar to the electric Graetz bridge, and as the pneumatic engine, a turbine or "Tesla" type engine is preferably used. The displacer of the engine has preferably at least two longitudinally, axially and opposite each other situated recesses preferably with the profile of a double-

100 convex lens, and in the vertical section has the shape composed of a semicircular element ended with a part having the profile of an obtuse- angled triangle with rounded vortex. Also preferably, in one circular two-piece cylinder or in two cylinders there is a displacer located with shape in the vertical section composed of semicircular element ended

105 by a part with the profile of an obtuse-angled triangle, vortex of which is ended with axially situated element comprising a rectangular part evolving into a semicircular part. Preferably the engine has a two-piece cylinder in the shape similar to oval, and the displacer situated therein has, in the vertical cross-section, the shape of a semicircular element

1 10 pointed with a portion with the profile of an obtuse-angled triangle, vortex of which is ended axially situated element composed of a rectangular part evolving into a semicircular part. Preferably one two- piece cylinder or both cylinders of the engine have, in their vertical cross-section, a shape similar to oval having on the internal heated

1 15 surface thereof several recesses creating ribs and functioning as radiators, and opposite them, in their cooled parts, they have a recess in the form a ring segment. Also preferably the engine's two-piece circular cylinder on both of its two-piece circular cylinders there are located one or two displacers having, in their vertical cross-section, a shape

120 composed of a part with shape close to semicircular that through a shape composed of a part similar to semicircular, evolving, through a concave radius, into a convex radius and then into subsequent semicircular part but with smaller radius, from the axis of symmetry of which there is a rectangular element protruding ended by an element

125 with the profile of a concave spherical cap. Preferably the in engine's two-piece circular cylinder or in both of its two-piece circular cylinders having several recesses on their inner surfaces functioning as radiators and opposite them, a recess in the form of a ring segment there is a displacer or displacers located having in their vertical section the shape

130 composed of a semicircular part evolving into a part with the shape of an obtuse-angled triangle, from the vertex of which there is a rectangular element protruding ended with an element in the form of a concave spherical cap. Preferably one two-piece cylinder or both of two-piece cylinders of the engine have a shape close to an oblate oval in

135 which a displacer or displacers are located with, in their vertical cross- section, a shape composed of a semicircular part evolving into a part with the shape of an obtuse-angled triangle, from the vertex of which there is a rectangular element protruding ended with an element in the form of a concave spherical cap, or the cylinders have the shape similar

140 to an oblate oval, and in their heated and cooled parts they have identical rectangular recesses situated opposite each other.

Fundamental advantages of the present design of pistonless rotary Stirling engine according to the invention with respect to the previously known design solutions of the engine include: complete elimination

145 expensive piston and rod systems, pneumatic actuators and the related problems with proper sealing o pistons in their cylinders. Moreover, utilisation of two or more number of heated and cooled chambers in the pistonless rotary Stirling engine results in that the executive component of the engine, that is a turbine, vane or "Tesla"-type pneumatic engine,

150 is in each case supplied with twice as high absolute pressure compared to classic Stirling engines known earlier and composed of one cylinder with a displacer and another one with a piston. An additional advantage of the engine according to the invention consists in the possibility to use the heat energy in any form for supplying it as heating the hot gas

155 chambers can be provided by means of any heat source such as solar energy, steam, geothermal energy, chemical energy as well as energy of combustion of any type of fuel, including natural gas. Further, cooling of cold chambers can be provided by means of a stream of cooled air, cold water or other medium with low temperature.

160 The subject of the invention is shown in its different embodiments in the following figures, of which Fig. 1 shows the pistonless rotary Stirling engine in the first of its embodiments having a single cylinder with rotor located therein and functioning as a displacer, representing a first version of its shape in the axial cross-section; Fig. 2— the same 165 engine in the vertical section along line A-A; Fig. 3— the same engine in the vertical section along line B-B; Figs. 4-7— the same engine in axial cross-sections showing position of its rotor-displacer and position of the pneumatic engine's rotor in four working cycles shifted by 90° with respect to each other; Figs. 8-11 — the same engine with its

170 pneumatic engine position shown in four consecutive duty cycles in the vertical section along C-C line of Figs. 4-7; Figs. 12-15— the same engine with position of its rotor shown in four operation cycles in vertical cross-sections along line D-D of Figs. 4-7; Fig. 16— the second version of embodiment of the engine's rotor-displacer shape in

175 the engine in the vertical section along line B-B; Fig. 17— the third version of embodiment of the engine's rotor-displacer shape in the vertical section along line B-B; Fig. 18 — the fourth version of embodiment of the engine's rotor and cylinder in the vertical section along line B-B; Fig. 19— the fifth version of embodiment of the

180 engine's rotor and cylinder in the vertical section along line B-B; Fig.

20— schematic diagram depicting the principle of operation of the same engine with the first embodiment version of its rotor-displacer shown in Figs. 1-3; Fig. 21— the pistonless rotary Stirling engine in the second example of its embodiment comprising two cylinders with

185 rotary displacers with shape shown in Fig. 17 located in the cylinders and mounted on a common shaft, in the axial cross-section; Fig. 22— the same engine in the vertical section along line E-E; Fig. 23— the same engine in the vertical section along line F-F, Fig. 24— the same engine in the vertical section along line G-G; Figs. 25-28— the same

190 engine in the axial cross-sections showing location of both displacers thereof and the rotor of the pneumatic engine in its four working cycles shifted with respect to each other by 90°; Figs. 29-32— the same engine with location of rotor of its pneumatic engine shown in its four working cycles, in vertical cross-sections along line H-H; Figs. 33-36

195 — the same engine with location of its first rotor-displacer shown in four working cycles, in vertical cross-sections along line -K; Fig. 37- 40— the same engine with location of its second rotor-displacer shown in four working cycles, in vertical cross-sections along line L-L; Fig. 41— the second embodiment version of shape of rotor-displacer and

200 cylinder of the engine shown in Fig. 23 in the vertical section along line F-F and G-G; Fig. 42— the third embodiment version of the rotor- displacer and cylinder of the engine shown in Fig. 23 in the vertical section along lines F-F and G-G; Fig. 43— the fourth embodiment version of rotor-displacer and cylinder of the engine shown in Fig. 23 in

205 the axial cross-section along lines F-F and G-G; Fig. 44— the fifth embodiment version of rotor-displacer and cylinder of the engine shown in Fig. 23 in the vertical section along lines F-F and G-G; and Fig. 45— a schematic diagram depicting the principle of operation of the engine with the first embodiment version of its rotor-displacer

210 shown in Figs. 21^10.

The pistonless rotary Stirling engine according to the first example of its embodiment shown in Figs. 1-15 and 20 comprises a cylinder (1), a shaft (2) mounted tight-fitted and rotationally therein with disk jointing pieces (3 and 4) protruding outside and bearing-supported two ends (5

215 and 6) of the shaft axle, wherein the disk jointing piece (3) is permanently connected with body (7) of the vane pneumatic engine (8), rotor (9) of which, located in its cylindrical part (10) is fastened on one end (5) of shaft being put into rotary motion by means of a pneumatic start-up engine (1 1), and the side shield (4) is permanently connected

220 with the second cylinder face (1). The cylinder (1) of the engine comprises two identical hermetically sealed parts— a heated (12) and a cooled (13) one separated from each other with thermal insulation (14), of which the heated part (12) is connected with heater (15) and, by means of a common air duct (16) through opening (17), with the upper

225 heated part of body (7) of the pneumatic engine (8), whereas the cooled part (13) of cylinder (1) is connected with cooler (19) and, by means of the common air duct (18) through opening (20), with lower part lower part of body cylinder (7) of the pneumatic engine (8). Further, rotary shaft (2) of the engine functioning as a gas displacer has two recesses

230 (21) located longitudinally and opposite each with the profile similar to this of a double-convex lens, functioning as chambers (22 and 23) filled with heated working gas (24) and cooled working gas (25).

The principle of operation of the engine according to the invention consists in that after previous activation of heater (15) and cooler (19)

235 and achieving a suitable temperature difference between chambers (22 and 23) of rotary shaft (2) filled with gas (24), for instance air, a starter (1 1) is activated and starts rotary motion of the shaft and rotor (9) of pneumatic engine (8), and rotation thereof by 90° results in proper positioning of the chambers opposite from the heated part (12) and

240 cooled part (13) of cylinder (1). As a result of heating and cooling of the working gas in chambers (22 and 23), an increase of the gas pressure occurs in one of the chambers and decrease in the other. As a result of rotary motion, profile recesses (21 ) co-creating chambers (22) and (23) in shaft (2) situated opposite each other, channels (16 and 18)

245 are exposed by said chambers that supply the heated working gas (24) and the cooling working gas (25) to cylindrical part of body (7) of pneumatic engine (8), wherein the pressure difference acting on the engine results in occurrence at the end (5) of the shaft axle (2) of a torque causing rotary motion of the shaft axle together with its axle (2).

250 It follows from the above that the necessary condition to start the engine is to achieve appropriate temperature difference between the thermally separated parts (12) and (13) of the cylinder (1).

Further, in the course of shaft (2) rotating by 180°, openings (17 and 20) of air ducts (16 and 18) supplying the working (24) and cooling

255 (25) gas to pneumatic engine (8) are obscured by its rotor (9) and cylindrical shaft (2) surfaces, respectively, situated between its gas chambers (22 and 23), while after the rotor being turned by 180°, the chamber (23) of the rotor cooled in the previous working cycle stands opposite the heated part (12) of cylinder (1), and the heated chamber

260 (22) of the rotor at the same time stands opposite the cooled part (13) of cylinder (1). Then, analogously to the previous working cycle, the working gas (24 and 25) existing in chambers (22 and 23) of shaft (2) is heated and cooled, respectively, thus acting on rotor (9) of pneumatic engine (8) thorough ducts (16 and 18) supplying the gas and exposed at

265 that moment by chambers (22 and 23). The mass of shaft (2) of the engine functions as a classic Stirling regenerator allowing for additional transfer and recovery of energy from heated part (12) and cooled part (13) of cylinder (1) through exchange thereof by means of working gas (24 and 25) contained in chambers (22 and 23) of the cylinder.

270 The above-described structure of single pistonless engine according to the invention creates a possibility to connect a plurality of such modules in series or in parallel by means of coupling them together, mechanically or magnetically, on a common shaft and thus to construct arbitrarily large "flat panels" generating mechanical or electrical energy

275 by means of appropriate electric current generators. The design of the above-described engine according to the invention allows also to construct an engine with shaft (2) provided with larger even number of recesses (21) as well as heated (22) and cooled (23) chambers ensuring thus more balanced operation of the engine; further, it allows also to

280 construct a series version of the engine by increasing the number of chamber pairs (22 and 23) along a single shaft (2), or a parallel version by means of construction of a stack of shafts (2) rotating parallel to each other, thus allowing to convert heat energy delivered over larger surfaces into the mechanical energy.

285 In other example embodiments of this Stirling engine, its rotary shaft (2), as shown in Fig. 16 in the vertical section along line B-B of Fig. 1 has the shape composed of semicircular element (26) ended with a part with the profile of an obtuse-angled triangle (27) with its vertex rounded and, as shown in Fig. 17 in the vertical section along line B-B

290 of Fig. 1 , it also has the shape composed of semicircular element (26) ended with a part with profile of an obtuse-angled triangle (27) vertex of which is ended with an axially situated element comprising a rectangular part (28) upper and of which evolves into a semicircular part (29) while, as shown in Fig. 18 in the vertical section along line B-

295 B of Fig. 1 , its cylinder (30) has the shape close to an oval and the shaft (2) located therein has the shape identical as the shaft shown in Fig. 17 and further, as shown in Fig. 19 in the vertical section along line B-B of Fig. 1, its cylinder (31) has the shape similar to an oval having in its upper part three rectangular recesses (32) functioning as radiators, and

300 in the lower part a recess (33) in the form of a ring sector. Moreover, in other example embodiments of this Stirling engine, the cylinder (1) is permanently connected with body (7) of a turbine pneumatic engine or a Tesla-type pneumatic engine, and to starting the Stirling engine, an electric starter (1 1) is used.

305 The pistonless rotary Stirling engine in its second example embodiment shown in Figs. 21— 5 comprises two hermetic cylinders (35 and 36) mechanically connected to each other, and a common shaft (37) located therein ends (38 and 39) of which protrude outside side disk jointing pieces (40 and 41) attached to front face of the cylinders, and further

310 analogous disk jointing piece (42) is located between the inner faces of cylinders (35 and 36) that form an immovable monolith therewith, wherein on shaft (37) in each of cylinders (35 and 36), profile displacers (43 and 44) are mounted. Each of cylinders (35 and 36) of the engine comprises two identical hermetically sealed parts— heated

315 (45) and cooled (46) ones separated from each other with thermal insulation (47), wherein the heated parts (45) are connected with heater (48) and, by means of common air duct (49) through pneumatic rectifier (50) connected therewith and opening (51), with upper heated cylindrical part (52) of body (53) of pneumatic engine (54), while the

320 cooled parts (46) of both cylinders (35 and 36) are connected with cooler (55) and, by means of a common air duct (56) through pneumatic rectifier (50) connected therewith and through opening (57), with lower cooled cylindrical part (52) of body (53) of pneumatic engine (54). Cylindrical part (52) of body (53) of pneumatic engine (54) has an

325 internal partition (58) separating the body into two chambers (59 and 60), wherein the body (53) of chamber (60) is connected rigidly with disk jointing piece (40) of cylinder (35), and in its upper part there are two check valves (61) of the pneumatic rectifier (50) mounted within the circuit of hot air duct (49), whereas in its lower part there are two

330 check valves (62) of the rectifier mounted within the circuit of cold air duct (56), the check valves (61 and 62) of the rectifier represent a system similar to the circuit of electric Graetz bridge. The valve bridge of pneumatic rectifier (50) allows to change the two-directional alternating gas flow at its input into unidirectional gas flow at its output.

335 Moreover, in chamber (60) of body (53) there is rotor (85) of pneumatic vane engine (54) mounted on shaft (37), whereas body (53) of the rotor, as it was already noted above, is permanently connected with cylinder (35), and shaft (37) is supported on bearings (63) mounted in disk jointing pieces (40, 41, 42) of cylinders (35 and 36) and in body (53) of

340 pneumatic engine (54). Further, profile displacers (43 and 44) mounted on common shaft (37) and functioning as stirrers as shown in Fig. 17 and in Figs. 23 and 24 in vertical cross-sections along lines F-F and G- G of Fig. 23 have identical forms composed of semicircular parts (26), ended by parts with the profile of an obtuse-angled triangles (27)

345 vortexes of which are ended with axially situated elements composed of rectangular parts (28), upper ends of which evolve into semicircular parts (29) but with radii significantly less than those of semicircular parts (26), and profile chambers (64 and 65) created between the and the inside surfaces of cylinders (35 and 36) are filled with working gas

350 supplied after heating or cooling thereof through ducts (49 and 56) by means of valves (61 and 62) of pneumatic rectifier (50) to appropriate parts of cylinder body (52) of pneumatic engine (54).

In further example embodiments of this two-cylinder Stirling engine, its displacers (43 and 44), as shown in Fig. 41 in the vertical section along

355 lines F-F and G-G of Fig. 21 , have also the identical shape composed of a part with shape similar to semicircular (66) evolving through convex (67) and concave (68) radius into another semicircular part (69) but with significantly smaller radius from the symmetry axis of which there is a rectangular element (70) protruding ended in the upper part

360 thereof with element (71) in the form of a concave spherical cap, whereas the displacers are located in slightly oval cylinders.

Further, as shown in Figs. A2-AA in the vertical section along lines F-F and G-G of Fig. 21 , cylinders (72) of the engine have the shape similar to oval with three upper rectangular recesses (73) functioning as

365 radiators and a lower recess (74) with the profile of a ring sector, in which on shaft (37) there are displacers (75) mounted having in the vertical section a semicircular shape (76) ended with an obtuse-angled triangle (77), from the vertex of which a rectangular element (78) protrudes ended with element (79) in the form of a concave spherical

370 cap, or in cylinders (80) with the profile of a rectangle with two semicircular sides (81) (oblate oval) on shaft (37) there are displacers (75) mounted with the above-described shape, or cylinders (82) have the cross-section in the form similar to a rectangle with rounded sides with rectangular recesses (84) situated opposite each other, in which on

375 common shaft (37) there are displacers (75) mounted also with shapes described above.

In the above-described example embodiments, to put the shaft (37) into rotational motion, a mechanical or pneumatic or electric starter (1 1) was applied using energy supplied from outside. 380 The principle of operation of the Stirling engine according to the above- described example consist in that after previous putting into operation the heater (48) and the cooler (55) and achieving appropriate temperature difference between thermally isolated cylinders (35 and 36) and in chambers of the engine filled with gas, e.g. air, starter (1 1) is

385 activated and starts rotary motion of shaft (37) together with displacers (43 and 44) fastened thereon as well as rotor (85) of pneumatic engine (54). In the starting position, displacers (43 and 44) of both cylinders (35 and 36) fastened on shaft (37) are located between hot and cold parts of each cylinder, and rotation thereof by 90° results in the solid of

390 the first displacer (43) pressure transferring the working gas to the cold part of the cylinder, while in the second cylinder motion of displacer (44) pressure transfers the working gas to the hot part of the cylinder. At that point, gas in the first cylinder (35) is subject to cooling, while in the second cylinder (36) the gas is subject to heating, respectively, and

395 the working gas pressure difference generated between the two cylinders is transferred through pneumatic rectifier (50) to appropriate input (51) and output (57) of pneumatic engine (54) mounted on common shaft (37). The occurred working gas pressure difference thus acts on pneumatic engine (54) resulting in occurrence of a torque on

400 part (38) of its shaft (37) resulting in rotation of the whole shaft (37) together with displacers (43 and 44) mounted thereon. In the course of shaft rotation by 180°, solids of the displacers, functioning also as stirrers, rotate by 180° transferring the working gas from cold part to hot part in the first cylinder (35) and from hot part to cold part in the

405 second cylinder (36), respectively. At that point, in the first cylinder (35) a change of working gas pressure occurs from low to high one and, analogously, a pressure change occurs from high torn low one in the second cylinder (36). The alternated pressure difference between volumes of the two cylinders (35 and 36) decreasing in time is

410 transferred to the pneumatic rectifier (50) output of which through valves (61 and 62) supplies a turbine pneumatic engine (54) resulting in occurrence of a torque. Conversion of alternating working gas flow into unidirectional flow necessary to power the turbine of pneumatic engine (54) is achieved in pneumatic rectifying bridge (50). Masses of

415 displacers (43 and 44) mounted eccentrically on shaft (37) represent a classical Stirling regenerator allowing for additional recovery and transmission of energy coming from hot part to cold part of each cylinder through additional energy exchange occurring by means of appropriate displacer.

420 Also in this case there is a possibility to construct a pistonless rotary Stirling engine with the use of pistons not connected by a common shaft. To this end, the cylinders should be positioned one after another (in series) or side by side (in parallel) and a mechanical coupling between them should be ensured by means of a system of magnets, racks or toothed belts. Such a method of combining a plurality of such modules in series or in parallel by means of magnetic or mechanical couplings allows to construct arbitrarily large flat "panels" generating mechanical energy or electric energy by means of appropriate electric power generators.