Heat Engine

Abstract

A heat engine is provided. The heat engine includes a chassis, a work output member, and an actuation mechanism for actuating the work output member. The chassis supports one or more heat engine components including the work output member. The work output member is adapted to generate and output mechanical power to a power generation system for generating electrical power. The actuation mechanism includes a first actuator band array and a second actuator band array connected to displace the work output member in a first direction and a second direction, respectively, in response to thermal exposure. A thermal switching mechanism is operable to cyclically expose each of the first actuator band array and the second actuator band array to heat to cause cyclic displacement of the work output member in the first direction and the second direction to generate mechanical power.

Description

Detailed Description of the Invention

[0001] CROSS REFERENCE TO PRIOR APPLICATIONS This application claims priority from U.S. Patent Application No. 63 / 364,805, filed May 17, 2022, and U.S. Patent Application No. 63 / 371,259, filed August 12, 2022. The contents of these prior applications are incorporated herein by reference as if set forth in their entireties.

[0002] [Technical field] The present disclosure relates generally to heat engines and, more particularly, to heat engines capable of operating with low temperature sources and / or low temperature differentials, for example, between a natural environment or between a natural environment and a waste heat source.

[0003] [Background technology] Concerns about global warming and the need to address them have led to significant policy changes around the world, especially in developed countries, to reduce the use of fossil fuels required for energy demand. Although fossil fuels are abundantly available and still account for a large portion of the world's energy demand, interest in the use of alternative energy resources with less environmental impact is constantly evolving. Examples of alternative energy resources include nuclear energy and technologies that utilize wind and solar energy. However, these technologies have significant limitations and have not yet been widely used. For example, nuclear power plants have significant installation risks and environmental side effects due to radioactive waste contamination. Furthermore, while the use of renewable energy resources such as solar power systems and wind power plants has the advantage of not polluting the environment and curbing global warming, it still has significant limitations compared to fossil fuels, such as high costs, unstable supply, and geographical location of availability. Therefore, much research is being conducted to explore potential ways to reduce the use of fossil fuels, increase the feasibility, and reduce the investment costs of utilizing natural and renewable energy resources. Furthermore, it is hoped that these potential solutions will simultaneously contribute to solving global warming.

[0004] Another example of a natural energy resource is the large stores of thermal energy present in the environment, for example, air, water, and land. However, these thermal energy stores are limited in their ability to meet energy demands due to the small temperature differentials. Most of the conventional methods used to generate electricity from thermal energy cannot function unless the temperature of the working fluid is fairly high. For example, there must be a rapid gas expansion sufficient to create mechanical motion that can be used to generate electricity, which is the functional principle of gas turbines, steam power plants, and other combustion engine types used to generate electricity. Alternatively, compared to other conventional methods of heat exchange systems, the use of heat pipes as an efficient heat transfer mechanism has been known and used for decades. In general, heat pipes are known to be used for waste heat recovery and have been adopted for several practical applications, but the low temperature waste heat exchanged by heat pipes has not yet been used to generate electricity.

[0005] Systems have also been developed that utilize natural resources to generate electricity. For example, US Patent Publication No. 2017 / 0314539 discloses a rotary actuator that includes fibers with a twisted structure that continuously rotate in response to temperature fluctuations and convert thermal energy that has been wasted in the surrounding environment into mechanical energy, which is then used to generate electricity. US Patent No. 4,341,075 discloses a method and apparatus for converting low-temperature thermal energy into mechanical or electrical energy, in which at least one liquid or gas chamber performs work in response to temperature fluctuations. US Patent No. 10,615,720 discloses a generator that includes a deformation unit and a piezoelectric unit. The deformation unit is coupled to the piezoelectric unit, comprises a conductive polymer, and is configured to deform when in contact with moisture, thereby exerting a mechanical force on the piezoelectric unit to generate electricity. US Patent No. 10,072,638 discloses an apparatus for harvesting thermal energy using pulsed heat. Furthermore, US Patent No. 9,488,128 discloses a type of thermal torque engine that uses a hot box heated by a thermal agent and a wheel with multiple canisters mounted on the periphery, with the diametrically opposed canisters connected by conduits. Alternating exposure of the opposed canisters to heat causes the pressurized refrigerant to move to the opposing canister, resulting in a change in balance due to the shift in refrigerant weight, which creates a torque that moves the wheel. US Patent Publication No. 2014 / 0150419 discloses an engine with multiple movable masses (e.g., fluids contained in containers and movable between the containers) coupled to a shaft and positioned around the shaft. When subjected to a pressure difference, the mass moves to the higher container, thereby increasing its potential energy and creating a gravitational moment that urges the multiple masses to rotate in a particular direction.

[0006] There remains a need for a system that overcomes at least one of the deficiencies known to those skilled in the art, such as a system that can efficiently utilize the low temperature heat and / or low temperature differentials present in natural thermal storage to generate power for small and large scale applications.

[0007] 〔overview〕 In one aspect, a heat engine is provided. The heat engine includes a chassis for supporting one or more heat engine components. The heat engine further includes a work output member supported on the chassis and adapted to generate and output mechanical power to a power generation system for generating electrical power. The heat engine also includes an actuation mechanism coupled to and adapted to actuate the work output member to generate the mechanical power. The actuation mechanism includes a first actuator band array operably connected to the work output member and adapted to displace the work output member in a first direction in response to thermal exposure. The actuation mechanism also includes a second actuator band array operably connected to the work output member and adapted to displace the work output member in a second direction in response to thermal exposure. Additionally, the actuation mechanism includes a thermal switching mechanism operable to periodically expose each of the first actuator band array and the second actuator band array to heat to cause periodic displacement of the work output member in the first and second directions to generate mechanical power.

[0008] In another aspect, a power generation system is provided. The power generation system includes a power generation system for generating electrical power and a heat engine operably coupled to the power generation system. The heat engine includes a chassis for supporting one or more heat engine components. The heat engine further includes a work output member supported by the chassis and adapted to generate and output mechanical power to the power generation system for generating electrical power. The heat engine also includes an actuation mechanism coupled to and adapted to actuate the work output member to generate mechanical power. The actuation mechanism includes a first actuator band array operably connected to the work output member and adapted to displace the work output member in a first direction in response to thermal exposure. The actuation mechanism also includes a second actuator band array operably connected to the work output member and adapted to displace the work output member in a second direction in response to thermal exposure. Additionally, the actuation mechanism includes a thermal switching mechanism operable to periodically expose each of the first actuator band array and the second actuator band array to heat to cause periodic displacement of the work output member in the first and second directions to generate mechanical power.

[0009] BRIEF DESCRIPTION OF THE DRAWINGS Next, an embodiment will be described with reference to the accompanying drawings.

[0010] FIG. 1 is a simplified schematic diagram of a power generation system according to one embodiment of the present disclosure.

[0011] 2 to 9 show a heat engine according to a first embodiment of the present disclosure.

[0012] 10 to 13 show a heat engine according to a second embodiment.

[0013] 14 to 21 show a heat engine according to a third embodiment.

[0014] 22 to 26 show a heat engine according to a fourth embodiment.

[0015] 27 to 31 show a heat engine according to a fifth embodiment.

[0016] 32 to 36 show a heat engine according to a sixth embodiment.

[0017] 37 to 43 show a heat engine according to a seventh embodiment.

[0018] Figures 44 to 51 show a heat engine according to aspect 1 of the eighth embodiment.

[0019] Figures 52 to 56 show a heat engine according to aspect 2 of the eighth embodiment.

[0020] Figures 57 to 59 show a heat engine according to aspect 3 of the eighth embodiment.

[0021] Figures 60 to 62 show a ninth embodiment of a heat engine that uses solar thermal energy for its operation.

[0022] 63 to 67 show a heat engine according to a tenth embodiment.

[0023] Detailed Description of the Invention The present disclosure provides a heat engine that can operate by utilizing the abundant thermal energy present in nature, e.g., by utilizing the low temperature difference between two adjacent environments, such as air, water, land, and / or by utilizing heat from low temperature sources, such as low temperature waste heat. The thermal energy stored in the environment can vary within tens of degrees Celsius in response to geographical location, e.g., due to diurnal and / or seasonal temperature changes, and the heat engine of the present disclosure can utilize such temperature changes to generate electrical power. Examples of such natural thermal energy resources include, but are not limited to, the temperature difference between the water at the bottom of an ocean, sea, lake, etc., and a geographical location nearby that experiences sub-zero temperatures in winter or where solar thermal energy collected near land or sea is a low temperature area, and / or land or desert that experiences significant temperature changes during the day and night. The thermal energy is converted by the heat engine described herein into the mechanical output required to generate electrical power. Furthermore, the heat engine according to various embodiments presented herein can operate to generate electrical power from natural resources regardless of the actual temperature of the two adjacent environments, i.e., as long as they are different, either too high or too low.

[0024] The heat engines described herein provide an effective solution to global warming by lowering the temperature of an environment (e.g., one of the adjacent environments in which the heat engine is implemented), as well as reducing the need for fossil fuels. These heat engines provide a cost-effective way of utilizing thermal energy from ambient environments and other resources to generate electrical power, as compared to other conventional systems. Furthermore, the heat engines according to the present disclosure can be implemented in a variety of power generation applications, such as, but not limited to, renewable power plants, battery charging stations for electric vehicles (EVs), offshore and isolated bases, especially in very hot or very cold locations, and telecommunication posts that require little infrastructure. Furthermore, these heat engines can be scaled up, for example, to power small or large appliances, vehicles, homes, buildings, etc., without departing from the scope of the claimed subject matter. Several embodiments of heat engines will now be described with reference to the accompanying drawings.

[0025] FIG. 1 illustrates a simplified schematic diagram of an exemplary power generation system 100 according to various embodiments of the present disclosure. The power generation system 100 may be configured to generate electrical power to power facilities such as homes, buildings, remote base stations, communication posts / towers, electric vehicle chargers, and the like. As illustrated, the power generation system 100 includes a heat engine 102, a power generation system 104 including a generator for generating electrical power, a power conditioning system 106, and a heat exchanger 114 coupled to the heat engine 102 and configured to provide thermal energy to the heat engine 102. The power generation system 100 may also include a controller 110 for operating one or more components of the power generation system 100, such as the heat engine 102, the heat exchanger 114, and the power generation system 104, based on one or more data signals received from the heat engine 102, the heat exchanger 114, and the power generation system 104. The data signals may include, for example, temperature, flow rate, pressure data signals, and the like, which may be utilized by the controller 110 to control the operation of one or more components of the power generation system 100. It will be appreciated that in various embodiments, the controller 110 may include additional instrumentation and control systems for controlling the operation of other components of the power generation system 100 .

[0026] The heat engine 102 may be a device capable of converting heat or thermal energy received from a thermal energy source via the heat exchanger 114 into useful work and providing a mechanical output (e.g., by means of a rotating or vibrating member) capable of driving a mechanical load. The heat engine 102 may include a gearbox, and / or other mechanical mechanisms to regulate the rotational output of the heat engine 102 required for generating electricity. In various embodiments, the thermal energy source (hereafter referred to as the heat source) may be any low temperature source, including but not limited to low temperature waste heat from a power plant, or an environmental thermal energy gradient between two or more adjacent or proximate geographic locations, or a natural storage source of solar energy, geothermal energy, or other types of available heat sources, such as, for example, thermal energy from waste heat or other commercial or industrial processes. In some examples, solar thermal energy, such as collected in evacuated glass tubes commonly used in solar water heaters or solar chillers, or collected by Miller-wise collectors, or collected by any other collection means, may also be effectively utilized to operate the heat engine 102 described herein. While the present disclosure is provided with respect to a heat engine capable of operating in low temperature gradients and environments, it can be understood that the concepts presented herein can likewise be implemented to utilize high temperature sources without departing from the scope of the claimed subject matter.

[0027] The power generation system 104 may be a device or system capable of converting mechanical power (received from the heat engine 102) into electrical power. The power generation system 104 may include a conventional (rectified electromagnetic) generator, an alternator, a piezoelectric generator, etc. In some examples, the power generation system 104 may be a generator and may include any equipment associated with a generator, such as bearings, thermal management / cooling systems, transformer(s), alternating current (AC)-direct current (DC) inverters / converters, DC-DC converters, control electronics, couplings, gears / gearing, clutches, transmissions, etc.

[0028] The output from the power generation system 104 may be provided to a power conditioning system 106 for converting the generated power into an appropriate form required in response to an end use. In various embodiments, the power conditioning system 106 may include AC and / or DC converters, transformers to increase or decrease voltage, etc., to make the power output from the power generation system 104 appropriate according to the requirements of the end use. For example, the power conditioning system 106 may be configured to commission or modify the generated power output from the generator, such as rectifying or inverting, or modifying the voltage, for use as a charging station or to connect the power plant to a grid.

[0029] In some embodiments, the controller 110 may include operative connections to various sensors and systems of the power generation system 100 and be configured to receive information regarding one or more operating parameters thereof, e.g., temperature, pressure, frequency, voltage, current, etc., or the position of one or more actuators, and send commands via the connections to the various actuators and systems to operate, for example, the heat engine 102 and the heat exchanger 114. Although a single controller is illustrated, it will be understood that the power generation system 100 may include multiple controllers, e.g., separate controllers for controlling the operation of the heat engine 102, the heat exchanger 114, the power generation system 104, etc. In some embodiments, the controller 110 may be embodied as a computing device (e.g., a computer) having a single microprocessor or multiple microprocessors, computer memory (e.g., a non-transitory computer readable medium), and other components configured to receive inputs from sensors and / or other components of the heat engine 102, the heat exchanger 114, and the power generation system 104, and generate output signals based on the inputs. For example, such a controller may include memory, secondary storage, a clock, and processing hardware for accomplishing tasks consistent with the present disclosure.

[0030] Next, an example of a heat engine 102 according to an embodiment will be described with reference to FIGS. 2-9. The heat engine 102 includes an engine chassis 202 having a longitudinal axis 204 and a transverse axis 206. The engine chassis 202 supports one or more heat engine components, including but not limited to those described herein. As shown more clearly in FIG. 3, the engine chassis 202 may be embodied as a rectangular chassis frame having a first longitudinal end 208 and a second longitudinal end 210 along the longitudinal axis 204 and longitudinally opposite the first longitudinal end 208. The chassis 202 may include a first longitudinal arm 212 and a second longitudinal arm 214 extending along the longitudinal axis 204, and a first transverse arm 216 and a second transverse arm 218 disposed opposite the longitudinal ends of the chassis 202 and extending laterally between the first longitudinal arm 212 and the second longitudinal arm 214 along the transverse axis 206. In some embodiments, the chassis 202 may also include a third lateral arm 220 disposed proximal to the first lateral arm 216, a fourth lateral arm 222 disposed proximal to the second lateral arm 218, and a fifth lateral arm 224 disposed between the third lateral arm 220 and the fourth lateral arm 222, for example extending laterally in the middle of the chassis 202. Additionally, a longitudinal support arm 226 may extend longitudinally between the fifth lateral arm 224 and the third lateral arm 220. It may be understood that the structural configuration of the chassis 202 is merely exemplary and that any other form, shape, and configuration of the chassis 202 may alternatively be implemented to achieve similar results.

[0031] In one embodiment, the heat engine 102 includes a work output member, such as an output shaft 228, attached at one longitudinal end, e.g., the first longitudinal end 208 of the chassis 202. The heat engine 102 may be configured to convert thermal energy into mechanical work, for example, by rotating the output shaft 228. The rotation of the output shaft 228 may serve as an input to the power generation system 104 via a gearbox 230, which converts the received input mechanical rotational power into electrical power. For example, the gearbox 230 may include one or more components for performing a number of functionalities, including, but not limited to, increasing the speed of rotation of the output shaft 228 and / or converting the rotation of the output shaft 228 into an appropriate input rotational power for the power generation system 104 (e.g., converting bidirectional rotation into unidirectional rotation), and transmitting the rotational power via an outlet shaft (not shown) to a conductor shaft or rotor (not shown) of the power generation system 104 to generate electrical power by known mechanisms.

[0032] The heat engine 102 further includes an actuation mechanism coupled to and configured to actuate a work output member, i.e., in this example, an output shaft 228, to generate a mechanical rotational force. As shown more clearly in FIGS. 4 and 7, in some embodiments, the output shaft 228 may be mounted to a mounting assembly 232 coupled between the first lateral arm 216 and the third lateral arm 220 and to the longitudinal support arm 226 of the chassis 202. The mounting assembly 232 includes a mounting wall 233 coupled to the third lateral arm 220 and the longitudinal support arm 226. Further, a mounting base member 234 and a mounting top member 236 including bearings therein for supporting the output shaft 228 extend longitudinally between the first lateral arm 216 and the third lateral arm 220 and are coupled to the mounting wall 233. The mounting assembly 232 may further support a gear assembly 238 for actuating, in this example, rotating, the output shaft 228. In one embodiment, the gear assembly 238 may be a rack and pinion gear assembly and may have a linear rack gear 240 meshed or engaged with a circular or pinion gear 242, where linear motion of the rack gear 240 may cause rotation of the pinion gear 242, which in turn may rotate the output shaft 228. The linear rack gear 240 may be supported on a guide bar 244 that extends laterally along the length of the first lateral arm 216. The linear rack gear 240 may include an elongated through receptacle (not shown) that allows the guide bar 244 to pass through and mount the gear 240 thereto. As shown, the guide bar 244 may be secured at both ends to the first longitudinal arm 212 and the second longitudinal arm 214 via fastening mechanisms 246 and 248, respectively. The guide bar 244 may be adapted to provide smooth linear restraint and guidance for the rack gear 240 during operation. It will be understood that the gear assembly 238 and its components are merely exemplary and that other arrangements may be used to achieve similar results without departing from the subject matter recited in the claims.

[0033] Additionally, as part of the actuation mechanism, the heat engine 102 may further include an actuation mechanism 249 having one or more actuation components configured to actuate the work output member by displacing the work output member when exposed to heat. To this end, the actuation mechanism 249 may include a first actuator band array 250 (first actuation component) and a second actuator band array 252 (second actuation component) configured to drive the rack gear 240 in a first direction (indicated by arrow D1) and an opposite second direction (indicated by arrow D2) on the guide bar 244. In one embodiment, the first actuator band array 250 and the second actuator band array 252 each include a single actuator band (hereinafter referred to as the first actuator band 250 and the second actuator band 252) made of a material having a high coefficient of thermal expansion or contraction. As will be appreciated, the coefficient of thermal expansion describes the tendency of materials to change (or increase) their size, shape, area, volume, and / or density in response to, for example, temperature changes. Similarly, a thermal contraction coefficient describes the tendency of a material to change (or decrease) in size, shape, area, volume, and / or density, etc., in response to a change in temperature. Thus, a high thermal expansion or contraction coefficient can correspond to a high tendency of a material to change dimensions in response to even small changes in temperature, such as those caused by a thermal energy source at room temperature. Thus, when exposed to a change in temperature, the actuator bands 250, 252 expand or contract to change their respective lengths, thereby exerting a pushing / pulling force on the linear rack gear 240, which displaces the gear 240 in either a first direction D1 or a second direction D2, as described later herein. The alternating cyclical displacement of the linear rack gear 240 in the first direction D1 and the second direction D2 then causes bidirectional rotation of a work output member, such as the output shaft 228.In an exemplary embodiment, the actuator bands 250, 252 may be embodied as stretched rubber bands, i.e., rubber bands in a stretched configuration that undergo a significant contraction in response to an increase in temperature and a significant expansion in response to a decrease in temperature and / or when heat is removed. Additionally, in some embodiments, the gearbox 230 may include one or more components (not shown) that convert these bidirectional rotations into unidirectional rotations, increase the speed of rotation to a level required by the power generation system 104 to generate electrical power, and transmit these output rotational powers to a generator assembly via an outlet shaft.

[0034] In the illustrated embodiment (shown more clearly in FIGS. 6 and 7 ), the linear rack gear 240 includes a band attachment member 254 having a first end 256 and a second end 258 therein adapted to receive and secure one end of each of the first and second actuator bands 250 and 252. The band attachment member 254 may be integrally formed with the linear rack gear 240 in some embodiments, while in some alternative embodiments, the band attachment member 254 may be a separate component coupled to the linear rack gear 240. The band attachment member 254 may include receiving holes in the first and second ends 256 and 258, respectively, for receiving and securing one first end of each of the first and second actuator bands 250 and 252 therein. Further, in embodiments, the second ends of each of the first and second actuator bands 250 and 252 are configured to be secured to the chassis 202 using fasteners, such as bushings. 5, the second end of the first actuator band 250 is secured at the second longitudinal end 210 by a bushing 260 to the end of the first longitudinal arm 212 proximal or adjacent to the second lateral arm 218 of the chassis 202. Similarly, the second end of the second actuator band 252 is secured at the second longitudinal end 210 by a bushing 262 to the end of the second longitudinal arm 214 adjacent to the second lateral arm 218 of the chassis 202.

[0035] In order to have a significant change in length of the bands 250, 252, and thus a significant displacement force exerted on the gear 240, the length and / or cross-section of the bands 250, 252 exposed to the temperature change may be selected according to the rate of expansion / contraction of a given length of the material in response to a temperature change. Thus, for materials with high thermal expansion / contraction coefficients, the longer the length of the band exposed to the temperature change (i.e., heat in this example), the greater the change in length and therefore the greater the displacement imparted to the gear 240. Thus, the length and / or cross-section of the bands 250, 252 exposed to the temperature change may be kept smaller for small scale applications than for large scale applications and may be modified accordingly to obtain similar results.

[0036] In some embodiments, the actuator bands 250, 252 may be configured to extend between the longitudinal ends 208, 210 of the chassis 202 and along the entire length of the longitudinal arms 212, 214 in one or more suitable configurations to have a desired length to be exposed to heat. For example, as shown in the illustrated embodiment, the actuator bands 250, 252 may extend linearly to cover the length of each longitudinal arm 212, 214 three times in an S-shaped configuration. However, the bands 250, 252 may be arranged in other configurations along the length of the longitudinal arms 212, 214 to achieve similar results.

[0037] To support the bands 250, 252, the chassis 202 may support multiple band contact assemblies mounted at various locations on the chassis 202 to facilitate stretching the actuator bands 250, 252 along the length of the longitudinal arms 212, 214. For example, in the illustrated embodiment, the chassis 202 may support six band contact assemblies 264, 266, 268, 270, 272, 274 to facilitate stretching the bands 250, 252 between the band attachment members 254 and the bushings 260, 262. As shown, two band contact assemblies, such as a first assembly 264 and a second assembly 266, may be configured to support the first actuator band 250 at the first longitudinal end 208 and may be connected to the first lateral arm 216 adjacent the first longitudinal arm 212. Similarly, two band contact assemblies, such as a third assembly 268 and a fourth assembly 270, may be configured to support the second actuator band 252 at the first longitudinal end 208 and may be connected to the first lateral arm 216 adjacent to the second longitudinal arm 214. Additionally, one band contact assembly, such as a fifth assembly 272, may be configured to support the first actuator band 250 at the second longitudinal end 210 and may be attached to the second lateral arm 218 adjacent to the first longitudinal arm 212. Finally, one assembly, such as a sixth assembly 274, may be configured to support the second actuator band 252 at the second longitudinal end 210 and may be attached on the second lateral arm 218 adjacent to the second longitudinal arm 214. As shown in Figures 4 and 5, each of the assemblies 264-274 includes a respective free rotating pulley, such as pulleys 276a-276f, collectively referred to as pulley 276, which are mounted to respective free running normal bearings, such as bearings 278a-278f, collectively referred to as bearing 278, which are mounted to a respective shaft, such as shafts 280a-280f, collectively referred to as shaft 280, that is fixed to the chassis 202 as shown.It will be understood that the number and location of these assemblies 264-274 are also merely exemplary and may be varied to achieve similar results.

[0038] The first actuator band 250 and the second actuator band 252 may be configured to be supported by these band contact assemblies 264-274 such that these assemblies can accommodate changes in length of the bands 250, 252 when exposed to temperature changes (heat according to this example) and exert a force on the rack gear 240 during operation. For example, when the actuator bands 250, 252 are exposed to heat and change in length (by contracting or expanding), the bands will generate forces in both directions acting on both ends, resulting in torque on the pulleys 276 of each of the six assemblies 264-274. Furthermore, because one end of the bands 250, 252 is fixed to the chassis 202, the pulleys 276 transmit the applied force to pull on the other end of the bands 250, 252 connected to the gear assembly 238 and displace the gear 240 in a corresponding one of the directions D1, D2.

[0039] As mentioned above, in the exemplary embodiment, the first actuator band 250 as well as the second actuator band 252 may be stretch elastomeric bands, such as stretched rubber bands, with one end secured to the band attachment member 254 of the gear assembly 238 and respective second ends secured to the chassis 202, while also being supported by respective band contact assemblies 264-274, as explained above. Due to their high thermal contraction coefficients, these stretched elastomeric actuator bands 250, 252, when exposed to thermal energy, contract and change their respective lengths, thereby exerting a tensile force to displace the gear 240 in a first direction D1 (i.e., in the direction of the first longitudinal arm 212) and an opposite second direction D2 (i.e., in the direction of the second longitudinal arm 214), respectively. According to various alternative embodiments, the actuator bands 250, 252 may be made of other similar elastomers, including but not limited to silicone-based rubber, polyurethane, styrene-butadiene copolymer, natural rubber, and / or any other material with a large coefficient of thermal expansion or contraction. Additionally, the actuator bands 250, 252 may be used in many different shapes and configurations, such as but not limited to bands having circular, rectangular, or other types of cross-sectional profiles. In some other embodiments, a long piece of flat sheet, or a long tube shape, and / or any other tubular configuration of the actuator bands 250, 252 may be implemented to achieve similar results. Additionally, while in this embodiment, two actuator bands are shown and described, it will be understood that the heat engine 102 may include any number of actuator bands as needed and appropriate for the end use.

[0040] The heat engine 102 may further be connected to a heat exchanger 114 for receiving thermal energy and exposing the first actuator band 250 and the second actuator band 252 to the thermal energy or heat. In an exemplary embodiment, the heat exchanger 114 may be embodied as a heat pipe 282 configured to expose the actuator bands 250, 252 to heat. As will be appreciated, a heat pipe is a two-phase heat transfer device that utilizes the latent heat of a fluid to transfer thermal energy from one location (e.g., an evaporator section) to another location (e.g., a condenser section) by simultaneous evaporation and condensation in a closed vessel. In one embodiment as illustrated herein, the heat pipe may be a thermosiphon, while in other alternative embodiments, the heat pipe may be a wick heat pipe or other type of heat pipe known in the art. In still other embodiments, the heat engine 102 may utilize any other type of heat exchange mechanism, including but not limited to radiation, conduction, and convection, to transfer thermal energy to the first actuator band 250 and the second actuator band 252.

[0041] As shown, the heat exchanger or heat pipe 282 includes a first heat exchange section 284, e.g., an evaporative section (hereinafter referred to as the evaporative section 284), having a working fluid therein for receiving heat or thermal energy from a heat source. The heat pipe 282 further includes a second heat exchange section 286, e.g., a condensing section (hereinafter referred to as the first condensing section 286), and a third heat exchange section 288, also a condensing section (hereinafter referred to as the second condensing section 288), disposed downstream of the first heat exchange section 284 and fluidly connected to the first heat exchange section 284 via a thermal switching mechanism 290. As shown in the illustrated example, the first condensing section 286 and the second condensing section 288 may be disposed along the first longitudinal arm 212 and the second longitudinal arm 214, respectively. Although the heat pipe 282 is illustrated and described as including only two condensing sections, it may be understood that the heat pipe may have any number of condensing sections that may be required in response to an end application. During operation, the working fluid in a liquid state absorbs heat in the first heat exchange section or evaporation section 284 and is converted to a pressurized vapor state. The vaporized heated working fluid then travels to the condensation sections 286, 288 where it picks up heat and condenses, turning back into a liquid again. To facilitate condensation of the vaporized working fluid, the condensation sections 286, 288 can be kept non-insulated or partially insulated from the outside. The condensed working fluid is returned to the evaporation section 284 to repeat the process. In some examples, a thermosiphon type heat pipe 282 may be used or may be preferred, where the environment in which the condensation sections 286, 288 are located is located at a higher elevation than the environment in which the evaporation section 284 is located, thereby oriented in such a way that gravity assists the heated working fluid to return from the condensation sections 286, 288 to the evaporation section 284 quickly. Examples of working fluids include, but are not limited to, water, carbon dioxide, ammonia, nitrogen, or other fluids suitable for operating the heat pipe 282.In some embodiments, the heat pipe 282 may be a low temperature heat pipe that may be configured to use a working fluid with a low boiling point, such as ammonia. However, other working fluids may alternatively be used to achieve similar results. The detailed operation of the evaporator section 284 and condenser sections 286, 288 of the present disclosure are described below with reference to Figures 8 and 9.

[0042] The heat pipe 282 may further include a first intermediate section 292, which may be an adiabatic section, configured to fluidly connect between the first heat exchange section or evaporator section 284 and the second heat exchange section or first condenser section 286 via a thermal switching mechanism 290. Similarly, the heat pipe 282 includes a second intermediate section 294, which is also an adiabatic section, configured to fluidly connect between the evaporator section 284 and the third heat exchange section or second condenser section 288 via a thermal switching mechanism 290. Each of the first adiabatic section 292 and the second adiabatic section 294 is placed in a lower temperature environment compared to the evaporator section 284 and is kept thermally insulated from the outside to deliver the vaporized working fluid to the corresponding first condenser section 286 and second condenser section 288.

[0043] Further, the first intermediate section or first adiabatic section 292 is fluidly connected to the first condensing section 286 by a first flow connecting member 296, while the second intermediate section or second adiabatic section 294 is fluidly connected to the second condensing section 288 by a second flow connecting member 298. As shown more clearly in FIG. 9 , the condensing sections 286, 288 may be disposed above the respective adiabatic sections 292, 294 and the chassis 202, while the adiabatic sections 292, 294 may be disposed below the chassis 202. Thus, the flow connecting members 296, 298 may be disposed vertically that may extend perpendicular to the longitudinal axis 204 of the chassis 202 to connect the adiabatic sections 292, 294 to the respective condensing sections 286, 288. Further, the heat pipe 282 may also include a first fluid return section 300 connected between the first condensing section 286 and the evaporative section 284 via a third flow connecting member 302. Similarly, the second fluid return section 304 may be connected between the second condensing section 288 and the evaporating section 284 via a fourth flow connecting member 306. As shown, the flow connecting members 302, 306 may also be disposed in a vertical position, and the fluid return sections 300, 304 may be disposed above the respective condensing sections 286, 288. In some embodiments, the flow connecting members 296, 298, 302, and 306 may include one-way check valves that allow one-way flow of the working fluid based on the pressure difference during operation. In some embodiments, when the colder environment is at a higher height or altitude than the warmer environment, the heat pipe 282 is oriented in such a way that the flow connecting members 296, 298 are considered to define the upper portion of the heat pipe 282, and the evaporating section 284 is considered to define the lower portion of the heat pipe 282. Thus, the vaporized working fluid releases heat and flows downward (assisted by gravity) through the corresponding one of the condensing sections 286, 288. It will be understood that the overall configuration and arrangement of the various components of heat pipe 282 described above is merely exemplary, and that other configurations could be implemented to achieve similar results without departing from the scope of the claimed subject matter.

[0044] Further, in some embodiments, each of the condensing sections 286, 288 may be a hollow polygonal vessel, e.g., a hollow rectangular cuboid shaped vessel, including one or more receptacles 308 disposed therein and receiving the first and second actuator bands 250, 252 extending therethrough. For example, the receptacles 308 may be configured to have a cross-sectional profile, e.g., a tubular profile, that complements the cross-sectional profile of the respective actuator bands 250, 252. The receptacles 308 may be configured to extend through the entire length of the respective condensing sections 286, 288 and may be secured, e.g., welded, to the ends of the respective condensing sections 286, 288. Thus, the portions of the actuator bands 250, 252 that extend into the receptacles 308 are exposed to heat, i.e., changes in temperature, released by the vaporized working fluid flowing through the respective condensing sections 286, 288. In the illustrated embodiment, each of the condensation sections 286, 288 may include three tubular receptacles 308 for receiving the respective actuator bands 250, 252 that are wound three times along the length of the respective longitudinal arms 212, 214. In order to have thermal conduction to the actuator bands 250, 252, in some embodiments, the receptacles 308 may be made of a thermally conductive material such as copper, while the remaining parts of the condensation sections 286, 288 may be kept partially or non-insulated from the outside to allow a cooler environment to cool the condensation sections 286, 288 and thus the vaporized working fluid flowing therethrough sufficiently fast after the heat released from the vaporized working fluid is absorbed by the actuator bands 250, 252. To this end, the outer body of the condensation sections 286, 288 may be made of aluminum, for example, which has half the thermal conductivity compared to the copper body of the receptacles 308. Additionally, the insulating sections 292, 294 may be thermally insulated from the outside to prevent heat loss from the vaporized working fluid before it reaches the condensing sections 286, 288. Once heat is released in the condensing sections 286, 288, the condensed working fluid returns to the evaporation section 284 via fluid return sections 300, 304.Additionally, the fluid returns 300, 304 are not thermally insulated from the outside to facilitate returning uncondensed working fluid to the evaporation section 284 as well.

[0045] Further, in some embodiments, the thermal switching mechanism 290 may be a flow control valve (hereinafter referred to as flow control valve 290) that is disposed in the evaporation section 284 to control and direct the flow of heated working fluid therefrom through respective insulating sections 292, 294 to either the first condensing section 286 or the second condensing section 288. In one embodiment, the flow control valve 290 may be embodied as a directional control valve that selectively allows the flow of fluid from the evaporation section 284 to one of the condensing sections 286, 288 at a time. In response to the position of the flow control valve 290, the heated or vaporized working fluid is directed to either the first insulating section 292 and the first condensing section 286 (i.e., when the valve 290 is actuated to be in the first valve position) or the second insulating section 294 and the second condensing section 288 (i.e., when the valve is actuated to be in the second valve position). Thus, the position of the flow control valve 290 may be alternately and cyclically switched between the first and second valve positions to alternately and cyclically direct heated working fluid to each of the first condensing section 286 and the second condensing section 288, thereby cyclically exposing each of the actuator bands 250, 252 to temperature changes or heat. As explained above, because the bands 250, 252 are connected at one end to the chassis 202, the continuous contraction or expansion (depending on the material) of the bands 250, 252 in response to the cyclic exposure to heat creates a torque on the pulley 276, which in turn transmits the applied force to pull the gear assembly 238, thereby cyclically displacing the gear assembly 238 in the first direction D1 and the second direction D2, causing bidirectional rotation of the output shaft 228.

[0046] The flow control valve 290 may be actuated and switched between a first valve position and a second valve position by a valve actuation system 310. In some embodiments, the valve actuation system 310 may be embodied as a mechanical actuation system configured to mechanically actuate the flow control valve 290, for example, by a snap mechanism connected to one or more moving components, for example, the output shaft 228 of the heat engine 102. In some alternative embodiments, the valve actuation system 310 may be embodied as a small external power source. In some still other embodiments, the valve actuation system 310 may be part of the controller 110, which may be configured to receive data signals from the heat engine 102, the heat pipes 282, and the power generation system 106, and may be configured to control the operation of the flow control valve 290 based on the received data signals. It will be appreciated that a mechanical valve actuation system 310 may be used for small to medium scale power generation applications, while an electrical valve actuation system 310 may be implemented for large scale applications. However, it will be appreciated that the off-site power generation system may consume much less power compared to the expected generating capacity of the large power plant.

[0047] In some exemplary embodiments, the heat engine 102 and heat pipes 282 may be placed in any facility that experiences a temperature difference such that the evaporative section 284 is placed in an environment having a temperature T1 that is greater than the temperature T2 of the environment in which the condensing sections 286, 288 and the insulating sections 292, 294 are placed. Simply put, the evaporative section 284 is placed in a warmer environment and the condensing sections 286, 288 and the insulating sections 292, 294 are placed in a colder environment. It will be appreciated that the thermal energy stored in the environment may vary from location to location by tens of degrees Celsius due to daily and seasonal temperature changes. The heat pipes 282 may be placed in any such environment and may be configured to use this stored thermal energy to expose the actuator bands 250, 252 to this thermal energy and drive the output shaft 228 to generate power as described above. Additionally, the heat engine 102 may be implemented in environments with extreme weather conditions, from very cold to very hot, and may use the temperature difference between two nearby natural thermal stores. In this manner, the heat engine 102 using the heat pipes 282 can enable the generation of power for small as well as large scale applications by using the thermal capacity of land, water, air, and / or other natural resources. In some other embodiments, the heat pipes 282 can be connected to a source of low temperature waste heat and the low temperature waste heat can be utilized to generate electricity in a manner similar to that described above.

[0048] 8 and 9, the operation of the heat pipe 282 will be described in more detail. As described above, the evaporator section 284 of the heat pipe 282 is positioned or disposed in an environment E1 having a temperature T1, and the condenser sections 286, 288 are positioned or disposed in an environment E2 having a temperature T2. According to an exemplary embodiment of the present disclosure, the temperature T2 is lower than the temperature T1, in that the evaporator section 284 is disposed in a warmer environment compared to that of the condenser sections 286, 288. The working fluid in the evaporator section 284 absorbs heat from the high temperature environment and is transformed from a liquid state to a heated and / or vaporized state. The heated or vaporized working fluid is then alternately and cyclically directed to each of the condenser sections 286, 288 by switching the flow control valve 290 between a first valve position and a second valve position. 8, in a first fluid flow cycle, for example, when the flow control valve 290 is in a first valve position, the flow of heated or vaporized working fluid is directed to follow a fluid path indicated by a first set of arrows 802, i.e., through the first insulating section 292 and the first flow connecting member 296 to the first condensing section 286. As the vaporized working fluid flows through the first condensing section 286, the first actuator band 250 disposed therein is exposed to heat released by the working fluid. The exposed portion of the first actuator band 250 then contracts, which creates bidirectional forces acting on both ends of the band 250 and generates a torque on the pulley 276 of the assembly 264, 266, 272 supporting the first actuator band 250. Since one end of the band 250 is fixed to the chassis 202, the pulleys 276a, 276b, 276e transmit the applied force to pull the connected end of the rack gear 240, thereby displacing the gear assembly 238 in the first direction D1 and rotating the output shaft 228 in the first direction D1. As the vaporized working fluid travels along the condensing section 286, it condenses back into a liquid state, which, together with any remaining non-condensed amount, is returned to the evaporation section 284 via the first fluid return section 300 and the third flow connecting member 302, as shown by arrow 804.

[0049] Further, in the next fluid flow cycle, for example, when the flow control valve 290 is in the second valve position, the heated or vaporized working fluid is directed along a fluid path indicated by the third set of arrows 806, i.e., through the second insulating section 294 and the second flow connecting member 298, toward the second condensing section 288. As the vaporized working fluid flows through the second condensing section 288, the second actuator band 252 is exposed to heat and contracts pulling the gear assembly 238 in the second direction D2, in a similar manner as described above.

[0050] In an embodiment, the first actuator band 250 and the second actuator band 252 are periodically exposed to heat by periodically switching the position of the flow control valve 290 as described above, which periodically displaces the gear assembly 238 in the opposite first direction D1 and second direction D2, thereby generating a continuous bidirectional rotation of the output shaft 228. The bidirectional rotation is further converted to a continuous unidirectional rotation by the gearbox 230 and accelerated using appropriate mechanisms and gears to a level required by the power generation system 104 for power generation. The power generation system 104, coupled to the outlet shaft of the gearbox 230, generates adjustable power in response to the application of the power generation system 100. For example, the power can be rectified for use as a charging station, conditioned for connection to a power grid, or fed to an inverter, the output of which can be used for other applications.

[0051] 10-62, alternative embodiments of heat engines in accordance with concepts presented in this disclosure are provided.

[0052] 10-13 show a heat engine 2102 according to a second embodiment of the present disclosure. The heat engine 2102 includes a chassis 2004 having two opposing longitudinal ends and configured to support various components of the engine 2102. The heat engine 2102 includes a work output member 2006 mounted at one longitudinal end of the chassis 2004. In one embodiment, as shown, the work output member 2006 may be embodied as a belt drive arrangement (hereinafter referred to as the drive arrangement 2006) including a drive member (e.g., a drive pulley member) 2008 and a driven member (e.g., a driven pulley member) 2010 supported on a shaft 2011 (shown in FIGS. 11 and 12) and connected to the drive member 2008 by a drive belt 2012. Rotation of the drive member 2008 drives the driven member 2010. In this embodiment, the output rotation of the driven member 2010 is transmitted by the gearbox 2014 to the generator assembly via an outlet shaft (not shown) in a similar manner as described above. The drive arrangement 2006 in this embodiment is configured to generate unidirectional rotation, as described in the following description, and thus the gearbox 2014 may not include an arrangement for converting bidirectional rotation of the output shaft to unidirectional rotation in this example. However, similar to the gearbox 230, the gearbox 2014 in this embodiment may also include mechanisms for increasing the speed of rotation, rectifying, and / or adjusting the rotational output provided to the generator assembly for the generation of electrical power.

[0053] 11, in some embodiments, the heat engine 2102 may include one continuous actuator band 2016 extending about the chassis 2004, which displaces the drive arrangement 2006 when exposed to heat. For example, the actuator band 2016 may be supported as a loop on multiple band contact assemblies (e.g., 10 band contact assemblies in this embodiment) attached to the chassis 2004, such that both ends are connected together and a first array portion 2018 having four long portions of the band 2016 extends along a first longitudinal arm and a second array portion 2020 having four long portions of the band 2016 extends along a second longitudinal arm of the chassis 2004. As shown, a third array portion 2019 (having two sections) of the band 2016 extends (in a loop) along a lateral arm 2027 at the second longitudinal end of the chassis 2004. The band contact assembly in this embodiment may also include an arrangement of pulleys, bearings, and shafts, and is therefore hereinafter referred to as a pulley arrangement for simplicity. For example, the heat engine 2102 (as shown more clearly in FIG. 11 ) includes a first set of two pulley arrangements 2022, 2024 mounted on a first lateral arm 2026 (provided at a first longitudinal end of the chassis 2004) adjacent to a first longitudinal arm, and a second set of two pulley arrangements 2028, 2030 mounted on the first lateral arm 2026 adjacent to a second longitudinal arm. A third set having one pulley arrangement 2032, 2034, 2036 is attached to a second lateral arm 2027 (provided at a second longitudinal end of the chassis 2004) adjacent the first longitudinal arm, and a fourth set of three pulley arrangements 2038, 2040, 2042 is attached to a second lateral arm 2027 adjacent the second longitudinal arm. Each of the pulley arrangements 2022, 2024, 2028, 2030, 2032, 2034, 2036, 2038, 2040, 2042 includes a respective shaft, such as shaft 2044 (only a portion of which is shown), and a one-sided rotation bearing, such as bearing 2046 (only a portion of which is shown).In this exemplary embodiment, the shaft 2044 of the pulley arrangement 2030 (e.g., the pulley arrangement disposed at the end of the first lateral arm 2026 and adjacent to the second longitudinal arm) can also rotatably support the drive member 2008 of the drive assembly 2006.

[0054] The heat engine 2102 further includes a heat exchanger such as a heat pipe 2282 for providing thermal energy to the actuator band 2016 to drive the drive arrangement 2006 in a manner similar to that described above. For example, the heat pipe 2282 includes an evaporative section 2284 that may be located in a warm or hot environment or connected to a low temperature waste heat source, and two condensing sections 2286, 2288 that are located in a low temperature environment compared to the environment of the evaporative section 2284. The condensing sections 2286, 2288 may be fluidly connected to the evaporative section 2284 via a flow control valve 2290 in a similar manner as described above. The condensing sections 2286, 2288 are kept partially insulated or non-insulated from the outside and are positioned along the longitudinal arms of the chassis 2004 to provide thermal exposure to the first array portion 2018 and the second array portion 2020 of the actuator band 2016, respectively. For example, even in this embodiment, each condensation section 2286, 2288 can include a number of thermally conductive tubular receptacles 2058 (shown in FIG. 13 ) extending therethrough for receiving respective portions of the actuator band 2016 therein. In the illustrated embodiment, each condensation section 2286, 2288 includes four tubular receptacles 2058 for receiving the four elongated portions forming each of the first array portion 2018 and second array portion 2020 of the actuator band 2016.

[0055] Additionally, a first insulating section 2292 and a second insulating section 2294 may also be connected between the evaporation section 2284 and the respective condensing sections 2286, 2288 via a flow control valve 2290. The insulating sections 2292, 2294 are connected to the respective condensing sections 2286, 2288 via respective fluid connections 2064, 2066. Additionally, fluid returns 2068, 2070 connect the condensing sections 2286, 2288 back to the evaporation section 2284 via respective fluid connections 2072, 2074 in a manner similar to that described above.

[0056] During operation, the working fluid absorbs heat in the evaporator section 2284 and travels to the flow control valve 2290. When the flow control valve 2290 is actuated (such as by the valve actuation system described above) to a first valve position, the heated working fluid is directed to follow a first fluid path (indicated by arrow 2076 in FIGS. 12 and 13), i.e., via the first insulating section 2292 and the first flow connection 2064 to the first condensing section 2286. As the vaporized working fluid flows through the first condensing section 2286, heat is transferred to the first array portion 2018 of the actuator band 2016. As the working fluid travels along the condensing section 2286, it condenses back into a liquid which is returned to the evaporation section 2284 via the fluid return section 2068 and flow connecting member 2072, along with any remaining non-condensed amount, as indicated by arrow 2078 (shown in FIG. 13 ).

[0057] In some embodiments, the total length of each of the array portions 2018, 2020 of the actuator band 2016 exposed to heat in the respective condensing sections 2286, 2288 may be less than half the total length of the actuator band 2016. Thus, when the first array portion 2018 of the band 2016 is exposed to heat, it contracts in both directions due to the constraint by the two pulley assemblies 2022, 2032 at either end. This contraction creates a force that rotates all of the pulley assemblies (e.g., assemblies 2022, 2024, 2032, 2034, 2036) connected to the array portion 2018 in one direction (indicated by arrow RD) due to the respective unidirectional rotating bearings 2046. The contracted portions add to each other, thereby pulling the second array portion 2020 towards the first condensing section 2286 (i.e., the warmer section), thereby rotating the drive member 2010 in that direction.

[0058] Similarly, when the flow control valve 2290 is switched to the second valve position, the heated working fluid is directed to follow a second fluid path (indicated by arrow 2080 in FIGS. 12 and 13), i.e., via the second insulating section 2294 and the flow connecting member 2066 to the second condensing section 2288. As the vaporized working fluid flows through the second condensing section 2288, heat is transferred to the second array portion 2020 of the actuator band 2016. As the working fluid travels along the condensing section 2288, it condenses back into a liquid, which is returned to the evaporation section 2284 via the fluid return section 2070 and the flow connecting member 2074, along with any remaining non-condensed amounts, as indicated by arrow 2082 (shown in FIG. 13).

[0059] When the second array portion 2020 is exposed to heat, it contracts again displacing the drive member 2008 in the same direction due to the unidirectional rotary bearings 2046 on the end pulley assemblies 2030, 2042, as described above. Thus, due to the unidirectional rotary bearings 2046 on all pulley assemblies, in this exemplary embodiment, continuous unidirectional rotation of the drive member 2008 is achieved by periodically switching the position of the flow control valve 2290 to periodically expose the array portions 2018, 2020 of the actuator band 2016, thereby unilaterally driving the driven member 2010 to provide input rotation to the generator assembly for generating electrical power.

[0060] 14 to 21, a heat engine 3102 according to a third embodiment is provided. The heat engine 3102 may be a scaled-up version of the heat engine 2102 for implementation in large-scale power generation applications. As shown, the heat engine 3102 includes a chassis 3004 having two opposing longitudinal ends and configured to support various components of the engine 3102. As will be appreciated, the chassis 3004 in this embodiment may be constructed larger than the chassis previously described to suit and accommodate larger scale applications. For example, as more clearly shown in FIG. 16, the chassis 3004 may include a base frame portion 3006, an upper frame portion 3008, and a number of support members 3010 connected between the upper frame portion 3008 and the base frame portion 3006 to form a hollow box-like structure of the chassis 3004 having a height H. The base frame portion 3006 has a frame structure having two longitudinal arms 3012, 3014, two lateral arms 3020, 3022 provided at a first longitudinal end of the chassis 3004, and two lateral arms 3024, 3026 provided at a second longitudinal end of the chassis 3004. Similarly, the upper frame portion 3008 also includes two longitudinal arms 3016, 3018, two lateral arms 3028, 3030 on the first longitudinal end of the chassis 3004, and two lateral arms 3032, 3034 on the second longitudinal end of the chassis 3004.

[0061] Additionally, the heat engine 3102 includes a work output member 3036 mounted to one longitudinal end of the chassis 3004. In this embodiment, the work output member 3036 may also be embodied as a belt drive arrangement (hereafter referred to as drive arrangement 3036) including a drive member 3038 and a driven member 3040 connected to the drive member 3038 by a drive belt 3042. Rotation of the drive member 3038 in turn drives the driven member 3040, whose output rotation is transmitted to the generator assembly by a gearbox 3044 via an outlet shaft (not shown) in a manner similar to that described above. It may be appreciated that the belt drive arrangement is merely one example and that in various alternative embodiments, other types of work output members may also be used to achieve similar results.

[0062] Further, in the illustrated embodiment, the heat engine 3102 may include a plurality of continuous actuator bands 3046, each stretched multiple times around the chassis 3004 as a loop (similar to the actuator band 2016 described above) and arranged in layers or stacks to cover the entire height H of the chassis 3004 along the length of the longitudinal arms 3012 and 3016, 3014 and 3018, and one of the lateral arms disposed at the second longitudinal end of the chassis 3004, forming a U-shaped configuration. Each of the actuator bands 3046 may be embodied as a band having a tubular cross-section adapted to expand or contract when exposed to heat to displace the drive arrangement 3036, similar to the other actuator bands previously described. For example, the bands 3046, as shown in FIG. 17, may be arranged such that a first array portion 3048 of the band 3046 extends through the height H between the first longitudinal arms 3012 and 3016 of the base frame portion 3006 and the upper frame portion 3008, respectively. Similarly, the second array portion 3050 of the band 3046 can extend through a height H between the second longitudinal arms 3014 and 3018, and the third array portion 3052 can extend through a height H between the transverse arms 3026 and 3034. In one embodiment, the heat engine 3102 can include 26 actuator bands 3046 forming 104 long portions extending in a stacked or layered manner in each of the array portions 3048 and 3050. However, the number of actuator bands 3046 and long portions in each array portion 3048, 3050 is merely exemplary and may be varied to achieve similar results. For example, instead of multiple actuator bands, the heat engine 3102 can include a single long actuator band extending multiple times in a U-shape in a stacked configuration to achieve similar results.

[0063] As shown and described above with reference to FIG. 11, each of the actuator bands 3046 may have two ends connected together to make a loop that is supported by a number of band contact assemblies 3054 (e.g., ten band contact assemblies in this embodiment, with five assemblies along each of the longitudinal arms) that are mounted around the chassis 3004 in a similar manner. As shown, one of the band contact assemblies 3054 (such as band contact assembly 3054A) may be configured to support the drive member 3038 in addition to supporting the actuator band 3046. Each of the band contact assemblies 3054 may be adapted to extend through the height H of the chassis 3004. Additionally, as shown in FIG. 18, each band contact assembly 3054 includes a shaft 3056 that supports a number of pulleys 3058, each end of the shaft 3056 being mounted on a one-way rolling bearing 3060, with assembly 3054A including two pairs of one-way rolling bearings 3060 on which the corresponding shaft 3056 is supported. As will be appreciated, in this embodiment, the bearings 3060 may be positioned such that their corresponding rotational directions permit one-directional movement of the actuator band 3046. For example, the bearings 3060 on the outer band contact assemblies on either side of the chassis 3004, e.g., assemblies 3054A, 3054E, may be adapted to rotate in a first rotational direction RD1, while the bearings 3060 on the other assemblies, i.e., assemblies 3054C, 3054D, 3054E, may be adapted to rotate in an opposite, second rotational direction RD2. The rotational directions RD1 and RD2 may be configured to cooperate to move the actuator band 3046 only in the first rotational direction RD1, as shown in FIG.

[0064] The heat engine 3102 further includes a heat exchanger, such as a heat pipe 3062, for supplying thermal energy to the actuator band 3046 for driving the drive arrangement 3036. For example, the heat pipe 3062 includes an evaporative section 3064, which may be located in a warm or hot environment or connected to a low temperature waste heat source, and two condensing sections 3066, 3068, which are located in a low temperature environment compared to the environment of the evaporative section 3064. The condensing sections 3066, 3068, in this embodiment, may be configured as hollow blocks (as shown in FIG. 20) extending between the longitudinal ends of the chassis 3004 along a height H. Additionally, the condensing sections 3066, 3068 may be fluidly connected to the evaporative section 3064 via a flow control valve 3070, similar to that described above. The condensation sections 3066, 3068 are kept partially or insulated from the outside and adapted to provide thermal exposure to the first array portion 3048 and the second array portion 3050 of the actuator band 3046, respectively. To this end, each condensation section 3066, 3068 may include a number of thermally conductive receptacles 3072, e.g., tubular receptacles, (shown in FIGS. 20 and 21 ), for receiving therein a respective long portion of the actuator band 3046 and for transferring heat from the working fluid flowing therearound to the respective portion of the actuator band 3046. In the illustrated embodiment, each condensation section 3066, 3068 includes 104 tubular receptacles 3072, such that each tubular receptacle 3072 receives a corresponding long portion of the band in the respective first array portion 3048 and second array portion 3050.

[0065] Additionally, the first and second insulating sections 3074, 3076 may also be connected between the evaporator section 3064 and the respective condenser sections 3066, 3068 via the flow control valves 3070. In some embodiments, such as the illustrated example, the insulating sections 3074, 3076 may be connected to the respective condenser sections 3066, 3068 from outside the housing 3004 via respective fluid connection conduits 3078, 3080 (shown in FIG. 15 ). The fluid connection conduits 3078, 3080 may be adapted to extend along the height H of the chassis 3004. In some embodiments, the first and second insulating sections 3074, 3076 may be fluidly connected to the center of the respective fluid connection conduits 3078, 3080, which facilitate the flow of heated working fluid from the insulating sections 3074, 3076 to the respective condenser sections 3066, 3068. Additionally, the heat pipe 3062 may include two fluid return members 3082, 3084 connected to the first condensing section 3066 via an opening 3085 (only one shown in FIG. 21 ) in a first return connecting conduit 3086, and two fluid return members 3088, 3090 connected to the second condensing section 3068 via an opening 3091 (only one shown in FIG. 20 ) in a second return connecting conduit 3092. The fluid return members 3082, 3084, 3088, 3090 facilitate the return of condensed and non-condensed working fluid to the evaporation section 3064.

[0066] During operation, the working fluid absorbs heat in the evaporation section 3064 and travels to the flow control valve 3070. When the flow control valve 3070 is actuated (such as by a valve actuation system) to a first valve position, the heated working fluid is directed to follow a first fluid path (indicated by arrow 3093), i.e., via the first insulating section 3074 and the first flow connecting conduit 3078 to the first condensing section 3066. As the heated working fluid flows through the first condensing section 3066, heat is transferred to the first array portion 3048 of the actuator band 3046. As the heated working fluid travels along the condensing section 3066, it cools or condenses back into a liquid, which, together with any remaining non-condensed amount, is returned to the evaporation section 3064 via the two fluid return members 3082, 3084 and the first return connecting conduit 3086. When the first array portion 3048 of the band 3046 is exposed to heat, it contracts to exert a bidirectional force that rotates the band contact assembly 3054 (i.e., on which the array portion 3048 is supported) along a respective rotational direction (i.e., one of RD1 and RD2). As explained above, rotation of the assembly 3054 along the respective rotational direction cooperates to move the actuator band 3046 in a first direction RD1, thereby rotating the drive member 3038 in that direction.

[0067] Similarly, when the flow control valve 3070 is switched to the second valve position, the heated working fluid is directed through a second fluid path (indicated by arrow 3094), i.e., through the second insulating section 3076 and the second flow path connecting conduit 3080, to the second condensing section 3068. As the heated working fluid flows through the second condensing section 3068, heat is transferred to the second array portion 3050 of the actuator band 3046. As the heated working fluid travels along the condensing section 3068, it cools or condenses back into a liquid, which, together with the remaining non-condensed amount, is returned to the evaporation section 3064 via the two fluid return members 3088, 3090 and the second return connecting conduit 3092. When the second array portion 3050 of the band 3046 is exposed to heat, it contracts to exert a force in both directions that rotates the band contact assembly 3054 (i.e., what the array portion 3050 is supported on) along the respective rotational directions. Rotation of the contact assembly 3054 cooperates to move the actuator band 3046 again in the first direction RD1, thereby rotating the drive member 3038 in that direction.

[0068] Thus, by periodically switching the position of the flow control valve 3070 and periodically exposing the array portions 3048, 3050 of the actuator band 3046 to heat, continuous unilateral rotation of the drive member 3038 is achieved which in turn unilaterally drives the driven member 3040 to provide input rotation to the generator assembly for generating electrical power.

[0069] 22 to 26, a heat engine 4102 according to a fourth embodiment is provided. The heat engine 4102 includes similar structural features as those described with reference to the heat engine 3102, in that it includes a box-like chassis 4004 having an upper frame and a base frame, and a drive arrangement 4036 mounted at a first longitudinal end of the chassis 4004 and including a drive member 4038 and a driven member 4040 connected to the drive member 4038 by a drive belt 4042, all implemented in a similar manner. The output rotation of the driven member 4038 is further provided to a generator assembly by a gearbox 4044, in a similar manner as described above.

[0070] In this embodiment, the heat engine 4102 includes an actuator band 4046, which may be embodied as a single flat sheet-like stretched band piece having a height HB (shown in FIG. 24) that extends through a height H1 of the chassis 4004. The actuator band 4046 is folded multiple times along a longitudinal arm of the chassis 4004 and one of the lateral arms located at a second longitudinal end of the chassis 4004 (opposite the drive array portion 4036) to form a U-shaped configuration as shown. A first array portion 4048 (shown in FIG. 25) of the band 4046 extends on one side of the chassis 4004, i.e., between the longitudinal arm 4012 of the base frame and the longitudinal arm 4016 of the upper frame of the chassis 4004. Similarly, the second array portion 4050 of the band 4046 extends on the other side of the chassis 4004, i.e., between the longitudinal arm 4014 of the base frame and the longitudinal arm 4018 of the upper frame of the chassis 4004. Furthermore, the third array portion 4052 extends laterally at a second longitudinal end, between the lateral arm 4026 of the base frame and the lateral arm 4034 of the upper frame of the chassis 4004. The band 4046 may be supported on band contact assemblies 4054 (e.g., ten band assemblies 4054) provided around the periphery of the chassis 4004, one of the assemblies 4054A supporting the end of the band 4046 as well as the drive member 4038. In the illustrated example, the shaft 4056 of the band contact assembly 4054 may be implemented as a long cylindrical shaft extending through the height H1 of the chassis 4004 and suitable for supporting the sheet-like actuator band 4046. Additionally, the shaft 4056 is adapted to support a pulley and a unidirectional rotation bearing 4060, the respective directions of rotation of which are implemented in a manner similar to that described above with reference to the bearing 3060 of the heat engine 3102.

[0071] The heat engine 4102 further includes a heat exchanger, such as a heat pipe 4062, for supplying thermal energy to the actuator band 4046, which in turn drives the drive arrangement 4036. For example, the heat pipe 4062 includes an evaporative section 4064, which may be located in a warm or hot environment or connected to a low waste heat source, and two condensing sections 4066, 4068, which are located in a cooler environment compared to the environment of the evaporative section 4064. Each of the condensing sections 4066, 4068 may be implemented as a hollow block that extends between the longitudinal ends of the chassis 4004, in this embodiment, through a height H1 (i.e., one condensing section 4066 is between the longitudinal arms 4012 and 4016, and the other condensing section 4068 is between the longitudinal arms 4014 and 4018). Furthermore, the condensing sections 4066, 4068 may be fluidly connected to the evaporative section 4064 via a flow control valve 4070, in a manner similar to that described above. The condensation sections 4066, 4068 are adapted to be kept partially insulated or non-insulated from the outside and to provide thermal exposure to the first array portion 4048 and the second array portion 4050, respectively, of the actuator band 4046. To this end, each condensation section 4066, 4068 can include a number of thermally conductive hollow through receptacles 4072 (shown in FIGS. 23 and 25 ) for receiving a portion of the actuator band 4046 therein and transferring heat from the actuation fluid flowing therearound to the respective portion of the actuator band 4046. As shown in the illustrated embodiment, the hollow through receptacles 4072 are configured to have a rectangular cross-section that complements the rectangular profile of the band 4046.

[0072] Furthermore, the first insulating section 4074 and the second insulating section 4076 may also be connected between the evaporator section 4064 and the respective condenser sections 4066, 4068 via the flow control valve 4070. The insulating sections 4074, 4076 are further connected to the respective condenser sections 4066, 4068 via respective fluid connection conduits 4078, 4080 extending from the outside of the chassis 4004 along the height H1 of the chassis 4004. Furthermore, the heat pipe 4062 includes two fluid return members 4082, 4084, one end of which is connected to the first condenser section 4066 via a first return connection conduit 4086 and the other end of which is connected to the evaporator section 4062. Similarly, the two fluid return members 4088, 4090 are connected to one side of the second condenser section 4068 via a second return connection conduit 4092. The fluid return members 4082 , 4084 , 4088 , 4090 facilitate the return of condensed and non-condensed working fluid to the evaporation section 4064 .

[0073] The heat engine 4102, including the heat pipes 4062 and flow control valves 4070, may be configured to operate in a similar manner as described above for the heat engine 3102 to similarly cyclically expose the array portions 4048, 4050 to heat, thereby moving the actuator band 4046 and causing unidirectional rotation of the drive member 4038 and driven member 4040.

[0074] 27-31, a heat engine 5102 according to a fifth embodiment of the present disclosure is provided. The heat engine 5102 may be a scaled-up configuration of the heat engine 102 illustrated in FIGS. 2-9 above. The heat engine 5102 may include a large box-like chassis 5004 having a height H2, structured similarly to the chassis 3004, 4004 described above. The chassis 5004 includes two longitudinal ends 5005, 5007. The heat engine 5102 may include a work output member 5006 (shown in FIG. 29) similar to the output shaft 228 described above, the work output member 5006 being embodied as an output shaft (hereinafter referred to as output shaft 5006). The output shaft 5006 may be attached to a mounting assembly 5008 provided to the chassis 5004 at a first longitudinal end 5005. For example, the output shaft 5006 is supported by and driven by a top gear arrangement having an upper linear rack gear 5009A (shown in FIG. 27) and a top pinion gear (not shown), and a bottom gear arrangement having a lower linear rack gear 5009B and a bottom pinion gear 5010 (shown in FIG. 29). In some embodiments, the gear arrangement may also include a driven gear member 5011 coupled to a gearbox 5013 that converts bidirectional rotation of the output shaft 5006 into unidirectional rotation for providing input to the power generation system, in a manner similar to that previously described for the gearbox 230.

[0075] Additionally, the heat engine 5102 includes a first array of actuator bands 5250 and a second array of actuator bands 5252 that are configured to drive the linear rack gear 5009 in a first direction (indicated by arrow D1) and an opposite second direction (indicated by arrow D2) when exposed to heat, respectively. In some embodiments, as shown in FIG. 28, multiple actuator bands (similar to actuator bands 250, 252 described above) may be arranged in layers or stacks to extend through the height H2 and form the respective arrays 5250, 5252. In the illustrated embodiment, the heat engine 5102 includes 26 bands in each of the first array 5250 and the second array 5252. Alternatively, the first and second arrays of actuator bands 5250, 5252 may each be implemented as a single long tubular band that is folded and stretched in multiple layers (26 layers in this example) to cover the height H2 and form the respective arrays 5250, 5252. The number of layers illustrated herein is merely exemplary and may be varied to accommodate the scale of application without departing from the scope of the claimed subject matter.

[0076] Further, in the illustrated embodiment, each actuator band of the corresponding layer of the first array of actuator bands 5250 can have one end fixed to the chassis 5004, such as at the second longitudinal end 5007 along a vertical axis (not shown) extending between the fastening mechanisms 5246 and 5247. The second end of each actuator band in the first array 5250 can be fixed to a band attachment member 5019 on the first longitudinal end 5005. In some embodiments, the band attachment member 5019 can be part of the attachment assembly 5008, but in some alternative embodiments, it can be configured as a separate component to achieve similar results. Further, each actuator band of the corresponding layer of the second array of actuator bands 5252 can have one end fixed to the chassis 5004, such as at the second longitudinal end 5007, along a vertical axis (not shown) extending between the fastening mechanisms 5248 and 5249. Additionally, the second ends of the actuator bands in the second array 5252 may be secured to band attachment members 5019 on the first longitudinal ends 5005. Additionally, as more clearly shown in FIG. 30 , the mounting assembly 5008 includes a mounting plate 5017 coupled to the upper and lower linear rack gears 5009, the mounting plate 5017 including a number of band attachment members 5019 for receiving and securing various respective layers in each of the first and second arrays of actuator bands 5250 and 5252. For example, each layer of band attachment members 5019 may be implemented in a manner similar to that previously described for band attachment members 254, where each layer of band attachment members 5019 includes a respective first end for receiving and securing the second ends of the respective layers of actuator bands in the first array 5250 and a respective second end for receiving and securing the second ends of the respective layers of actuator bands in the second array 5252. Additionally, the mounting plate 5017 is configured to be supported by an upper guide bar (not shown) and a lower guide bar 5015 for movement in directions D1, D2 in response to forces exerted by the actuator bands 5250, 5252 of the first and second arrays, respectively.The top guide bar can be secured at its ends to the top longitudinal arms 5016, 5018 by fastening mechanisms 5246 and 5248, respectively. Similarly, the bottom guide bar 5015 can be secured at its ends to the bottom longitudinal arms 5012, 5014 by fastening mechanisms 5247, 5249, respectively.

[0077] Additionally, a number of band contact assemblies 5020, each including a shaft 5022, a pulley 5024, and a free-spinning bearing (not shown), are provided around the chassis 5004 for movably supporting the first and second arrays of actuator bands 5250, 5252. Each of the band contact assemblies 5020 may be configured to extend along a height H2 of the chassis 5004 and may be arranged around the chassis 5004 in a configuration similar to that provided for the band contact assemblies 264, 266, 268, 270, 272, 274 described above. Additionally, in the illustrated embodiment, each band contact assembly 5020 may include a shaft implemented as a long cylindrical shaft 5022 supporting a number of pulleys (one for each layer of actuator bands) and two free-spinning bearings attached to the end of the shaft 5022. When the array of actuator bands 5250, 5252 is exposed to heat, the band contact assembly 5020 cooperates to move the actuator bands 5250, 5252 in directions D1, D2 in a similar manner as described above for the actuator bands 250, 252 to generate bidirectional rotation of the output shaft 5006.

[0078] Similar to the other heat engines described above, the heat engine 5102 of this embodiment also includes a heat exchanger 5062, e.g., a heat pipe, for supplying thermal energy to the first and second arrays of actuator bands 5250, 5252 to in turn drive the output shaft 5006. As shown, the heat pipe 5062 includes an evaporative section 5064, which may be located in a warm or hot environment or connected to a low waste heat source, and two (or in some alternative examples more) condensing sections 5066, 5068, which are located in a cooler environment compared to the environment of the evaporative section 5064. Additionally, the condensing sections 5066, 5068 may be fluidly connected to the evaporative section 5064 via a flow control valve 5070 in a similar manner as described above. The condensing sections 5066, 5068 may be configured as hollow blocks extending between the longitudinal ends 5005, 5007 of the chassis 5004 along a height H2 in this embodiment. The condensation sections 5066, 5068 may be kept partially or non-thermally insulated from the outside and adapted to provide thermal exposure to the first and second arrays of actuator bands 5250, 5252, respectively. Each condensation section 5066, 5068 may include a number of thermally conductive receptacles 5072 (shown in FIG. 29 ) for receiving various layers of the arrays 5250, 5252 therein and for transferring heat from the heated working fluid flowing therearound to the actuator bands. In the illustrated embodiment, each condensation section 5066, 5068 includes 104 tubular receptacles 5072 such that each tubular receptacle 5072 receives a corresponding long portion of the actuator bands of the respective first array portion 5250 and second array portion 5252.

[0079] Furthermore, a first insulating section 5074 and a second insulating section 5076 may also be connected between the evaporative section 5064 and the respective condensing sections 5066, 5068 via the flow control valves 5070. In the illustrated embodiment, the insulating sections 5074, 5076 are connected to the respective condensing sections 5066, 5068 via respective fluid connection conduits 5078, 5080 from inside the housing 5004 (e.g., to achieve a compact design). The fluid connection conduits 5078, 5080 may be adapted to extend along the height H2 of the chassis 5004. Furthermore, the heat pipe 5062 may include two fluid return members 5082, 5084 connected to the first condensing section 5066 via a first return connection conduit 5086 and two fluid return members 5088, 5090 connected to the second condensing section 5068 via a second return connection conduit 5092. The fluid return members 5082 , 5084 , 5088 , 5090 can facilitate the return of condensed and non-condensed working fluid to the evaporation section 5064 .

[0080] During operation, the working fluid absorbs heat in the evaporation section 5064 and travels to the flow control valve 5070. When the flow control valve 5070 is in a first valve position, the heated working fluid may be directed to follow a first fluid path, i.e., via the first insulating section 5074 and the first flow connecting conduit 5078 to the first condensing section 5066. As the heated working fluid flows through the first condensing section 5066, heat is transferred to the first array portion 5250. As the working fluid travels along the condensing section 5066, it cools or condenses back into a liquid, which, together with the remaining non-condensed amount, is returned to the evaporation section 5064 via the two fluid return members 5082, 5084 and the first return connecting conduit 5086. When the first array portion 5250 is exposed to heat, it contracts and displaces the upper and lower linear rack gears 5009 in a first direction D1, which causes the output shaft 5006 to rotate in the direction D1 as well.

[0081] Similarly, when the flow control valve 5070 is switched to the second valve position, the heated working fluid is directed to the second condensing section 5068 via the second fluid path, i.e., the second insulating section 5076 and the second flow path connecting conduit 5080. As the vaporized working fluid flows through the second condensing section 5068, heat is transferred to the second array portion 5252. As the working fluid travels along the condensing section 5068, it condenses back to a liquid, which, together with the remaining non-condensed amount, is returned to the evaporation section 5064 via the two fluid return members 5088, 5090 and the second return connecting conduit 5092. When the second array portion 5252 is exposed to heat, it contracts to displace the upper and lower linear rack gears 5009 in a second direction D2, thereby rotating the output shaft 5006 in the direction D2 as well.

[0082] Thus, by periodically switching the position of the flow control valve 5070 and periodically exposing the array portions 5250, 5252 of the actuator band, continuous bidirectional rotation of the output shaft 5006 is achieved which is converted by the driven gear member 5011 and gearbox 5013 into unidirectional rotation to provide input to the power generation system.

[0083] 32-36, a sixth embodiment of a heat engine 6102 is provided. The heat engine 6102 includes a chassis 6004 and an output shaft 6006 (shown in FIG. 35) supported by a gear arrangement 6009, these components being implemented in a similar manner as described above for the chassis 5004 and the output shaft 5006. The gear arrangement may also include a driven gear member 6013 coupled to a gear box 6014 that converts bidirectional rotation of the output shaft 6006 into unidirectional rotation to provide an input to the generator assembly. It will be appreciated that converting bidirectional rotation to unidirectional rotation may be utilized in embodiments that do not utilize a one-sided constrained rotary bearing, and various mechanisms are well known to provide the necessary conversion.

[0084] In this embodiment, the heat engine 6102 includes a piece of sheet-like actuator band 6052 that extends through the height H3 of the chassis 6004. The actuator band 6052 defines a first array of actuator bands 6053 and a second array of actuator bands 6054 that are connected to drive the gear arrangement 6009 in directions D1 and D2, respectively, in a similar manner as described for the heat engine 5102 above. For example, the first array of actuator bands 6253 and the second array of actuator bands 6254 can each have one end fixed to the chassis 6004 and a second end fixed to the mounting plate 6016 and the linear rack gears 6009 (both upper and lower) of the mounting assembly 6008. The coupling of the actuator bands 6052 to the mounting plate 6016 drives the output shaft 6006 in directions D1 and D2 in a similar manner as described above. Additionally, the actuator band 6052 is supported by a number of band contact assemblies 6020 disposed about the periphery of the chassis 6004 in a similar manner as previously described.

[0085] Additionally, the heat engine 6102 includes a heat exchanger 6062 for providing thermal energy to the actuator band 6052 to drive the output shaft 6006. The heat exchanger 6062 is implemented in a similar manner, except that the condensing sections 6066, 6068 may include hollow receptacles 6070 having a contour complementary to the cross-sectional contour of the actuator band 6052. Additionally, the heat pipe 6062 includes an evaporating section 6064 that heats the working fluid, for example, from a cold source or a cold gradient environment. A flow control valve 6070 directs the flow of the heated working fluid through a first insulating section 6074 and a second insulating section 6076 to one of the condensing sections 6066, 6068, thereby exposing one of the arrays 6053, 6054 to heat.

[0086] When the first array portion 6053 is exposed to heat, it contracts and displaces the upper and lower linear rack gears 6009 in a first direction D1, thereby rotating the output shaft 6006 in the direction D1. When the valve 6070 is switched position and the second array portion 6054 is exposed to heat, it contracts and displaces the upper and lower linear rack gears 6009 in a second direction D2, thereby rotating the output shaft 6006 in the opposite direction D2. Thus, by periodically switching the position of the flow control valve 6070 and periodically exposing the array portions 6053, 6054 of the actuator band 6052, a continuous bidirectional rotation of the output shaft 6006 is achieved, which is then converted by the driven gear member 6013 and the gearbox 6014 into unidirectional rotation for providing an input to the generator assembly.

[0087] 37 to 43, a seventh embodiment of a heat engine 7102 is provided. The heat engine 7102 includes a chassis 7004 and a rotating cylinder 7006 rotatably supported on the chassis 7004. As shown, the chassis 7004 includes a mounting frame 7008 supported on a set of legs 7010 that may facilitate installation of the engine 7102 at a facility. The mounting frame 7008 includes a first arm 7012 and a second arm 7014 spaced apart to define a length L of the chassis 7004. The cylinder 7006 is rotatably supported on a main shaft 7016 (a work output member in this example) that is connected at its ends to the first arm 7012 and the second arm 7014. Additionally, the mounting frame 7008 and main shaft 7016 divide the cylinder 7006 longitudinally along the length L2 of the cylinder 7006 into two half sections 7006-1, 7006-2, one on each side of the mounting frame 7008.

[0088] The cylinder 7006 includes a first surface 7018 facing and coupled to the first arm 7012 and a second surface 7020 facing and coupled to the second arm 7014. Further, as shown in FIG. 37 and FIG. 41, the main shaft 7016 is connected to the first arm 7012 and the second arm 7014 by bearings 7022 and 7024, respectively, which are in turn connected to bearing housings 7026, 7028 fixedly attached to the first arm 7012 and the second arm 7014, respectively. The bearings 7022, 7024 may be configured to facilitate rotation of the main shaft 7016 during operation, as described below. Further, a first fixed bevel gear 7030 and a second fixed bevel gear 7032 are fixedly attached to the first arm 7012 and the second arm 7014, respectively. In one embodiment, the fixed bevel gears 7030 , 7032 and bearing housings 7026 , 7028 may be fixed to the mounting frame 7008 and therefore may not be rotatable relative to the frame 7008 .

[0089] Additionally, the heat engine 7102 includes a number of actuator band sets or arrays 7033 spaced around the circumference of the cylinder 7006 such that a first array of actuator band sets 7033-1 is provided on a first section 7006-1 of the cylinder 7006 and a second array of actuator band sets 7033-2 is provided on a second section 7006-2 of the cylinder 7006. In an exemplary embodiment, each array of actuator band sets 7033 includes a first actuator band 7034 and a second actuator band 7036 (shown more clearly in FIG. 39 ) that extend longitudinally between a first face 7018 and a second face 7020 of the cylinder 7006. The engine 7102 further includes a number of drive mechanisms 7037 (shown in FIG. 40 ) connected to respective actuator band sets 7033 and adapted to generate rotational power that is supplied to the power generation system and to utilize a portion of the generated rotational power for rotation of the cylinder 7006. For example, each drive mechanism 7037 includes a first chain and sprocket arrangement 7038 disposed on the first surface 7018 and including a chain 7041 (having sections 7041-1, 7041-2) that travels on a sprocket 7039, and a second chain and sprocket arrangement 7040 disposed on the second surface 7020 and including a chain 7043 (having sections 7043-1, 7043-2) that travels on a sprocket 7045. Each of the first chain and sprocket arrangement 7038 and the second chain and sprocket arrangement 7040 is configured to secure a respective actuator band set 7033 to the cylinder 7006 and the mounting frame 7008. A first end of the first actuator band 7034 is fixedly secured to the body of the cylinder 7006 toward the second surface 7020 by a fastening mechanism, such as a bolted fastener 7042 (shown more clearly in FIG. 40 ). A second end of the first actuator band 7034 is movably secured to a first chain section 7041-1 of the first chain and sprocket arrangement 7038 at the first surface 7018 by a movable fastening mechanism 7044.Additionally, a first end of the second actuator band 7036 is movably secured to a first chain section 7043-1 of the second chain and sprocket arrangement 7040 at the second surface 7020 by a movable fastening mechanism 7046 (shown more clearly in FIG. 40 ). A second end of the second actuator band 7036 is also movably secured to a second chain section 7041-2 of the first chain and sprocket arrangement 7038 by a movable fastening mechanism 7048.

[0090] In some embodiments, the heat engine 7102 can include a mounting flange 7050 extending circumferentially on the second surface 7020 of the cylinder 7006. The mounting flange 7050 is configured to support the second chain and sprocket arrangement 7040 and the guide bar 7052. For example, the mounting flange 7050 can include a number of openings 7054 disposed thereon to allow the chain sections 7043-1, 7043-2 and the guide bar 7052 to pass therethrough and be secured to components of the engine 7102, as described herein. In some embodiments, the mounting flange 7050 can be a separate component coupled to the cylinder 7006 by some fastening mechanism. However, in some other embodiments, the mounting flange 7050 can be integrally formed with the cylinder 7006. The guide bar 7054 may include a spring member 7056 and may be coupled to the second chain portion 7043-2 of the second chain and sprocket arrangement 7040 by a moveable fastener 7057 to permit linear movement of the actuator band as it expands or contracts in response to thermal exposure. The spring member 7056 may be biased to an extended position and may be configured to be compressed by action of the chain 7043 to accommodate changes in dimensions of the actuator band set 7033 when exposed to heat.

[0091] 40, each of the chain and sprocket arrangements 7038, 7040 is connected to a respective fixed bevel gear 7030, 7032 by a respective drive shaft 7058 (only one side shown), a set of bearings 7060, and a rotating gear, such as bevel gear 7062. In an exemplary embodiment, the bearing 7060 may be a unidirectional rotating bearing configured to rotate the shaft 7058, which in turn rotates the bevel gear 7062 in only one direction. Furthermore, in some embodiments, the heat engine 7102 includes a drive arrangement 7064 provided on one of the faces, such as the second face 7020, of the cylinder 7006 and attached to the second arm 7014, as shown in FIGS. The drive arrangement 7064 may be configured to transfer rotation generated by the main shaft 7016 to a power generation assembly 7066 that includes a gearbox with mechanisms for increasing rotation, coupled power generation including a generator, control elements, and output adjustment elements required to control and employ the power plant for a given application. In an exemplary embodiment, the drive arrangement 7064 may be embodied as a timing pulley arrangement (hereafter referred to as timing pulley arrangement 7064) including a drive pulley 7068 and a driven pulley 7070, respectively, and a timing belt 7072 connecting the drive pulley 7068 to the driven pulley 7070. The drive pulley 7068 is configured to be driven by rotation of the main shaft 7016 and drive the driven pulley 7070, which transfers its rotation to the power generation assembly 7066. The timing pulley arrangement 7064 includes teeth and pockets on the outer diameter of the pulley body and complementary teeth and pockets on the inner surface of the timing belt 7072. The timing pulley arrangement 7064 may be configured to provide the additional function of preventing slippage when the heat engine 7102 is operating. It will be appreciated that other types of gear arrangements may be used to achieve similar results.

[0092] The heat engine 7102 described in this exemplary embodiment can be placed in a location with two adjacent different temperature environments, where one environment temperature is greater or warmer than the other. For example, the bottom of a lake may contain a significant amount of water, e.g., at 4° Celsius, and provide a large thermal energy extraction potential when the temperature outside the lake can be below or around 0° Celsius in winter and above +30° Celsius in summer. The heat engine 7102 according to this embodiment can be used in such a location during most of the summer, spring, and fall when the surface layer remains unfrozen. Furthermore, the heat engine 7102 can also operate in hot and very hot locations, where the water is much colder than the outside. To this end, the heat engine 7102 may arrange the cylinder 7006, and select the size of the cylinder 7006, such that one of the sections 7006-1, 7006-2 of the cylinder 7006 is exposed to a first environment having a temperature T1, while the other of the sections 7006-1, 7006-2 is in a second environment having a temperature T2 lower than temperature T1. Thus, the section of the cylinder 7006 having the respective arrangement of actuator band sets 7033 exposed to heat provides a torque that is transmitted to rotate the main shaft 7016 (and also the cylinder 7006), thereby periodically exposing the other section of the cylinder 7006 having the other arrangement of actuator band sets 7033 to a warmer environment itself.

[0093] In operation, when one of the sections, such as section 7006-1, is exposed to a warm temperature T1, the actuator bands 7034, 7036 of the first array of actuator band set 7033-1 are exposed to heat and, as a result, contract. As the bands 7034, 7036 contract, their shortened lengths are summed by the drive mechanism 7037. For example, the contraction of the bands 7034, 7036 can exert a pulling force on the live fastener 7046, thereby pulling the chain 7043 towards the opposing surface, i.e., the first surface 7018, causing the sprocket 7045 to rotate in a counterclockwise direction. As a result, the shaft 7058 rotates in a counterclockwise direction, which is transmitted to the respective bevel gear 7062 and the fixed bevel gear 7032. Thus, rotation of the shaft 7058 and bevel gear 7062 of each of the actuator band sets 7033-1 in section 7006-1 contributes to rotating the main shaft 7016 in the same direction to generate rotational power that is transmitted to the generator assembly 7066 by the timing pulley arrangement 7064. Furthermore, because the fixed bevel gear 7032 does not rotate relative to the mounting frame 7008, rotation of the shaft 7058 and bevel gear 7062 results in rotation of the cylinder 7006 itself.

[0094] As the cylinder 7006 rotates, the other section, i.e., section 7006-2, is exposed to a warmer environment, causing the corresponding array of actuator band sets 7033-2 to contract, rotating their respective shafts and bevel gears in a similar manner, generating rotation in the main shaft 7016, again causing the cylinder 7006 to rotate in the same direction on its own. The exemplary arrangement of fixed bevel gear 7032, shaft 7058, and bevel gear 7062 functions as a thermal switching mechanism in this embodiment by periodically rotating the cylinder 7006 to periodically expose the actuator band arrays 7033-1 and 7033-2 to heat. Thus, by rotating the cylinder 7006, sections 7006-1, 7006-2 are periodically exposed to the heat of a warmer environment to generate rotational power that is supplied to the power generation assembly 7066. However, when the actuator band sets 7033, having contracted due to the heat of a warmer environment, are moved to a colder environment, they will relax, tending to rotate the sprocket 7045 in the opposite direction, i.e., clockwise, and potentially preventing unidirectional rotation of the main shaft 7016. Thus, because the shaft 7058 is supported by two bearings 7060 that only allow rotation in one direction, the shaft 7058 is only allowed to rotate in one direction (i.e., counterclockwise) and is restricted from rotating in the opposite direction, thereby producing unidirectional rotation of the main shaft 7016.

[0095] Further, in some embodiments, for example, for larger applications, the heat engine 7102 may be scaled up to include multiple cylinders 7006, each cylinder 7006 having a greater number of actuator bands (such as those shown in Figures 42 and 43) attached to their respective shafts 7058, functioning to rotate the respective cylinders and generate output rotational power in a similar manner as described above. Furthermore, in some other embodiments, for example, where the different points of temperature are significantly far apart, a modified configuration with two cylinders may be used, where one cylinder is inserted into each environment and connected to the other by a mechanical connection arrangement such as a chain or belt to transfer the generated displacement between the two. For example, in such an embodiment, the actuator bands 7034, 7036 may not be connected to the cylinder body, but may instead be movable around the circumference of the cylinder by its rotation. By inserting each of the two cylinders 7006 into one of the two environments, the generated displacement is created due to the respective array of actuator band sets being periodically moved from one environment to the other. A connecting mechanical arrangement can be configured to connect the two sections, such that forces generated by the actuator band set in the warm environment drive the connecting mechanical arrangement to displace the other array of the actuator band set from the cold environment to the warm environment, and vice versa.

[0096] 44-51, an eighth embodiment of a heat engine 8102 is provided. The heat engine 8102 includes a chassis 8004 and a number of cylinders 8006 supported on the chassis 8004. In the illustrated example, the heat engine 8102 includes six cylinders arranged in a circular fashion spaced apart around the periphery of the chassis 8004. However, it will be understood that the number and arrangement of cylinders illustrated and described herein are merely exemplary and the heat engine 8102 may include additional or fewer cylinders depending on the desired application.

[0097] The chassis 8004 may be implemented as a long base steel cylinder 8008 having a work output member, e.g., a main shaft 8009, rotatable therein to generate rotational power for the power generation system. The drive arrangement 8011 may be configured to transfer the rotation generated by the main shaft 8009 to a power generation assembly 8013, which may include a gearbox with mechanisms for increasing the rotation, a generator, control elements, and coupled power generation including output adjustment elements required to control and employ the power generation plant for a given application. In some examples, the drive arrangement 8011 may be embodied as a timing pulley arrangement including a drive pulley 8015 and a driven pulley 8017, respectively, and a belt 8019 connecting the drive pulley 8015 to the driven pulley 8017 (as shown more clearly in FIG. 48 ). The drive pulley 8015 is driven by rotation of the main shaft 8009 and is configured to drive the driven pulley 8017 , which provides rotation to the generator assembly 8013 .

[0098] The base cylinder 8008 can be divided into a lower portion 8008-1, which in this embodiment includes the evaporative section 8010 of the heat pipe 8012, and an upper portion 8008-2, which supports a cylinder 8006 that functions as a condensing section (hereafter referred to as the condensing cylinder 8006). Thus, the lower portion 8008-1 of the base cylinder 8008, which includes the evaporative section 8010, may be located in a warmer environment, while the upper portion 8008-2 and the condensing cylinder 8006 may be located in a colder environment. In some embodiments, the heat pipe 8012 may be embodied as a thermosiphon to allow the upper portion 8008-2 and the lower portion 8008-1 to be located at a large distance from each other, possibly up to 100 meters or more. Furthermore, as explained above, the vertical configuration of the heat engine 8102 allows the condensed working fluid to return to the evaporative section by gravity. Furthermore, the heat engine 8102 can be implemented in any location or facility having two environments with different environmental temperatures from each other. For example, the bottom of a lake may contain a significant amount of water at, say, 4°C, offering great potential for thermal energy extraction if the air temperature outside the lake can drop below -40°C in winter and above +40°C in summer.

[0099] 45, the upper portion 8008-2 of the base cylinder 8008 includes a first set of support arms 8014 (hereinafter referred to as upper support arms 8014) extending radially outward at an upper portion of the upper portion 8008-2, and a second set of support arms 8016 (hereinafter referred to as lower support arms 8016) extending radially outward at a lower portion of the upper portion 8008-2. The upper support arms 8014 and the bottom support arms 8016 are configured to mount the condensing cylinder 8006 therebetween. As can be appreciated, the base cylinder 8008, the upper support arms 8014, and the bottom support arms 8016 can be configured to function as an insulating section that fluidly connects and extends between the evaporator section 8010 and the condensing cylinder 8006.

[0100] Further, each condensing cylinder 8006 may be supported on a respective cylinder shaft 8018 having a respective axis of rotation. For example, the cylinders 8006 may be supported on the respective shaft 8018 by a set of bearings 8020, an outer portion of which may be attached to and held by a first bevel gear 8022 on the support arms 8014, 8016. Further, a second bevel gear 8024 is supported on the outer portion of the bearings 8020 and coupled to the first bevel gear 8022 to transmit rotational torque from the cylinder shafts 8018 of the condensing cylinders 8006 to a main bevel gear 8026 which rotates the main shaft 8009. As will be appreciated, the mounting arrangement described herein for mounting each of these condensation cylinders 8006 to the upper portion 8008-2 of the base cylinder 8008 can align the axis of rotation of each of these condensation cylinders 8006 (corresponding to the cylinder shaft 8018) parallel to the axis of rotation of the base cylinder 8008 (corresponding to the main shaft 8009), and the rotation of each of these cylinder shafts 8018 can contribute to the rotation of the main shaft 8009 via appropriate connecting mechanical elements.

[0101] In one example, the heat engine 8102 further includes a flow control valve 8028 (shown in FIG. 45), where one or more of the flow control valves 8028 associated with each of the condensing cylinders 8006 (as a thermal switching mechanism in this embodiment) may be configured to direct the heated working fluid to the top of one of the condensing cylinders 8006 via the flow connection member 8030 when switched to a corresponding valve position. In some embodiments, the flow control valve 8028 may be implemented as a simple one-way valve that allows one-way fluid flow based on its position. In some embodiments, every condensing cylinder 8006 may have its own flow control valve 8028 that may be selectively actuated during operation to allow heated working fluid to flow into each one of the respective cylinders 8006. In some other embodiments, the heat engine 8102 may include a single flow control valve 8028 that may be switched to different positions to direct heated working fluid to one of the cylinders 8006 at a time. As discussed above, the flow control valve 8028 can be mechanically or electrically actuated to switch between different valve positions during operation.

[0102] In an exemplary embodiment, each of the condensation cylinders 8006 includes an array of respective actuator bands 8032 having one or more actuator bands 8033 circumferentially disposed on an outer surface of the condensation cylinder 8006. As previously described, the array of actuator bands 8032 is configured to change dimensions, such as contract or expand, when exposed to warm temperatures or heat. As shown in FIG. 46 and FIG. 47, each condensation cylinder 8006 includes an inner cylindrical shell 8070 and an outer metallic cylindrical shell 8072 that define a fluid passage space 8073 therebetween. The actuator bands 8033 may be disposed in contact with the outer cylindrical shell 8072. Additionally, an inner surface (not shown) of the inner cylindrical shell 8070 may be covered with a layer of insulation. In operation, based on the position of the flow control valve 8028, heated working fluid may be directed to enter one upper portion of the cylinder 8006 and subsequently enter the fluid passage space 8073, thereby allowing the working fluid to flow from the top to the bottom of the cylinder 8006. Because the inner shell 8070 is thermally insulated, heat released by the working fluid flowing within the space 8073 is transferred to the outer shell 8072 and thus to the array of actuator bands 8032 in contact with the outer shell 8072. Furthermore, as the working fluid passes through the space 8073, it is condensed and returned to the evaporation section 8010 via respective return conduits 8075.

[0103] In an exemplary embodiment, each array of actuator bands 8032 includes a number of single bands 8033 that may be connected at one end in a side-by-side arrangement to a fixed flange 8034 provided at the bottom of the cylinder 8006. A second end of each actuator band 8033 may be connected to a moveable flange 8036 configured to move linearly up and down along the axis of the cylinder 8006 on one or more guide rods 8038. The moveable flanges 8036 are configured to move up and down in response to changes in the dimensions of the actuator bands 8033 in response to heat. As shown in FIG. 49, the guide rods 8038 may be secured at one end to a second fixed flange 8040 by a fastening mechanism 8042 and configured to slide through one or more guide holes 8044 provided in the moveable flange 8036. In this embodiment, each condensing cylinder 8006 has four guide rods 8038 spaced equidistantly around the circumference of the condensing cylinder 8006. However, other configurations and / or numbers of guide rods may be used with similar results.

[0104] Additionally, as shown in FIGS. 50 and 51, multiple drive arrangements 8045 may be provided on the condensing cylinder 8006 to convert linear contraction or expansion of the actuator band 8033 into bidirectional rotation of the drive shaft 8043. For example, the condensing cylinder 8006 may have four drive arrangements 8045 each spaced equidistantly around the circumference of the cylinder 8006. In some embodiments, the drive arrangements 8045 may include a linear gear member 8046 connected at one end to the movable flange 8036 by a fastening mechanism 8047 and passing through an aperture 8048 in the second fixed flange 8040 to engage a rotating gear member 8050 at the other end. The linear gear member 8046 may be configured to be linearly driven (i.e., driven up and down) by the action of the actuator band 8033 and the movable flange 8036, thereby rotating the gear member 8050. The linear gear member 8046 is also connected to a spring guide rod 8052 (hereinafter referred to as spring rod 8052) by a movable fastening mechanism 8054. The spring rod 8052 includes a spring 8053 supported thereon and is fixedly connected to the second fixed flange 8040 and undergoes relaxation when exposed to low temperatures, thereby providing a return force to the displaced actuator band 8033.

[0105] In the illustrated embodiment, the rotating gear member 8050 is mounted on a first bearing 8056 supported on one end of a shaft 8043. The shaft 8043 is in turn mounted on a second bearing 8058 and connected at the other end to a bevel gear 8060. In some embodiments, the first bearing 8056 and the second bearing 8058 may be one-way rotating bearings, with the first bearing 8056 free to move in opposite directions relative to the second bearing 8058. As a result, bidirectional rotation of the gear member 8050 is translated into one-way rotation of the bevel gear 8060. The bevel gear 8060 is further connected to a bevel gear 8022 that engages with, and is therefore rotatable by, an outer portion of the bearing 8020. The shaft 8018 passes through the bearing, the outer portion of which is fixed to the upper surface of the cylinder 8006 above the support arms 8014 and 8016. Thus, the bevel gear 8022 is attached to the shaft 8018 and rotates freely relative to the cylinder 8006. The bevel gear 8024 is also fixedly attached to the shaft 8018. Thus, the bevel gear 8024 rotates together with the shaft 8018 which is rotated by the bevel gear 8022.

[0106] 48 , the bevel gear 8022 may be operatively connected to the main bevel gear 8015 by a bevel gear 8077, a shaft 8078, a set of bearing boxes 8080, a bearing 8082, and a bevel gear 8084. Thus, the rotation of the bevel gear 8022 is transmitted to the main bevel gear 8015 through the above-mentioned mechanical connection, which in turn rotates the main shaft 8009 to provide output power to the power generation assembly 8013.

[0107] 52 to 56, a second embodiment of a heat engine 8102 (hereafter referred to as heat engine 8102A) is provided. The heat engine 8102A includes the same components as described above for the heat engine 8102, and therefore the reference numbers representing components identical to the heat engine 8102 are unchanged in these figures. However, in this embodiment, the drive arrangement 8045 for converting the linear motion of the actuator band 8033 into bidirectional rotation of the shaft 8043 is replaced by a different drive arrangement 9045. In the illustrated embodiment (as more clearly shown in Figures 55 and 56), the drive arrangement 9045 includes a chain member 9004 rotatably supported on a sprocket 9006. The chain member 9004 is connected at one end to the moveable flange 8036 by a fastening rod 9008 and at the other end to a spring rod 8052 by a fastening mechanism 8054. Sprocket 9006 is supported in two unidirectional rotating bearings 8056 and 8058 and is rotatable to produce unidirectional rotation of bevel gear 8060 in a similar manner as described above. The unidirectional rotation of bevel gear 8060 also produces rotation of bevel gear 8022, shaft 8018, and main shaft 8009 in a similar manner as described above for heat engine 8102.

[0108] 57-59, another embodiment of the heat engine 8102 (hereafter referred to as heat engine 8102B) is provided. In these figures, components that are identical to their respective components of the heat engine 8102 are labeled with the same reference numerals. In this embodiment of the heat engine 8102, instead of a plurality of actuator bands, the heat engine 8102B includes an array 1032 having a single sheet of actuator bands 1034 formed into a thin hollow cylinder and attached to the outer shell of each of the condensing cylinders 8006. The actuator bands 1034 may be connected to a moveable flange 8036 and configured to rotate the main shaft 8009 in a manner similar to that described above. Additionally, while FIGS. 58 and 59 illustrate the gear arrangement 9045 being implemented as a chain and socket arrangement (as described above), it may be understood that a drive arrangement 8045 including a linear gear member 8046 and a rotary gear member 8050 may also be used without departing from the scope of the claimed subject matter.

[0109] 60-62, a heat engine 1102 according to a ninth embodiment is provided. In some embodiments, the heat engine 1102 of this example is configured to utilize solar thermal energy for operation. For ease of explanation, the heat engine 1102 is structured and implemented in a manner similar to that described for the heat engine 8102 above. The heat engine 1102 includes a number of condensing cylinders 1106 disposed and supported on a chassis 1104 and adapted to receive heated fluid from the evaporative section 1110 via one or more flow control valves (not shown) in a manner similar to that described above for the heat engine 8102. In one embodiment, the heat engine 1102 may be disposed in a facility that is highly exposed to sunlight, and thus an umbrella 1105 may be disposed over the heat engine 1102 to cover each of the condensing cylinders 1106 to prevent exposure to direct sunlight, thereby also creating a relatively cool environment for the cylinders 1106 compared to those of the evaporative section 1110. As shown, in some embodiments, the entire heat engine assembly 1102 may be supported on the base 1108, although in some additional or alternative embodiments, the assembly may be supported on the chassis 1104 itself.

[0110] The heat engine 1102 may be operatively connected to a solar thermal energy capture system 1112 that absorbs solar energy from solar exposure to provide thermal energy for heating a working fluid in the evaporative section 1110. The heated working fluid is then delivered in a cyclical manner through flow control valve(s) to the condensing section, i.e., the condensing cylinder 1106 in this example, to rotate a work output member (not shown) and generate electrical power in a similar manner as described above.

[0111] The solar thermal energy capture system 1112 (hereinafter referred to as the system 1112) includes a number of solar thermal energy collector panels 1114 arranged around a water container 1116. In some embodiments, the solar thermal energy collector panels 1116 can partially surround the water container 1116, while in some other embodiments, the collector panels 1116 can be arranged to completely surround the water container 1116. Further, in some embodiments as exemplified herein, the water container 1116 has a top portion 1116-1 and a bottom portion 1116-2, with the top portion 1116-1 connected to the chassis 1104 and adapted to house the evaporation section 1110 therein. The water container 1116 may be cylindrical or cubic, or may be implemented in other shapes and / or designs. As will be appreciated, the size and capacity of the water container 1116 can be selected based on the size and scale of the heat engine 1102 and the solar thermal energy collector panels 1114 according to the desired end use. The water reservoir 1116 and the collector panel 1114 are adapted to provide a source of thermal energy for the operation of the heat engine 1102 .

[0112] As shown, solar thermal energy collector panels 1114 (hereafter referred to as collector panels 1114) face the sun and are appropriately angled to capture solar energy. Each collector panel 1114 includes an array of dual coaxial long glass tubes 1118, arranged parallel and close to each other and appropriately angled along their length to face and receive sunlight. Each pair of glass tubes are sealed coaxially and the space between them is evacuated to minimize heat loss. Additionally, the inner glass tube (not shown) of each pair of glass tubes is painted black on the outside to trap solar thermal energy therein. The blackened outside surface of the inner glass tube and the vacuum between the glass tubes allow water flowing through the inner glass tube to absorb solar heat when the collector panel 1114 is exposed to sunlight. Additionally, the inner glass tubes in each collector panel 1114 are connected on one side to a first pipe 1120 which is connected, for example, to the upper part 1116-1 of the water container 1116. The inner glass tubes are connected together on the other end to a second pipe 1122 (shown in FIG. 61) which in turn is connected, for example, to the lower part 1116-2 of the water container 1116.

[0113] In operation, as the working fluid, e.g., water, in the inner glass tube absorbs solar thermal energy and heats up, e.g., to 90° C., the heated water travels upward and flows through the first pipe 1120 to the top 1116-1 of the water vessel 1116. The displaced heated water in the inner glass tube is replaced with cold water from the bottom of the water vessel 1116 through the second pipe 1122. This circulation of water continues at the same time as the collector panel 1114 continues to absorb solar thermal energy. The evaporative section 1110 (located within the top 1116-1 of the water vessel 1116) absorbs heat from the heated water in the top 1116-1 to heat the working fluid therein, operating the heat engine 1102 to output rotational power and generate electricity, in a manner similar to that described above for the heat engine 8102.

[0114] Further, although heat engine 1102 is shown and described as being implemented in accordance with heat engine 8102, it will be understood that the solar thermal energy capture system 1112 described herein may be implemented in a similar manner with any other type of heat engine described above to enable each type of heat engine to operate using solar thermal energy.

[0115] 63-67, a heat engine 1202 according to a tenth embodiment is provided. The heat engine 1202 includes a chassis 1204 defining a first longitudinal end 1206 and a second longitudinal end 1208. The chassis 1204 may be divided into sections 1210, 1212, 1214, and 1216. In some embodiments, the sections 1210, 1212, 1214, and 1216 may be separated by flange members 1218, 1220, 1222, 1224, and 1226. An evaporation section 1228 may be provided at the first longitudinal end 1206 and may be mechanically coupled to a flange member 1218 provided at the first longitudinal end 1206 of the chassis 1204, for example, by any known fastening mechanism. The chassis 1204 may further support a first condensing section 1230 and a second condensing section 1232 that diverge at a second longitudinal end 1208 of the chassis 1204 (as shown more clearly in FIG. 64). The first condensing section 1230 and the second condensing section 1232 may be adapted to support a first actuator band 1256 (i.e., a first actuator band array in this example) and a second actuator band 1258 (i.e., a second actuator band array in this example) therein, respectively.

[0116] In this exemplary embodiment, the chassis 1204 further supports a first pipe 1234 and a second pipe 1236 (shown in FIG. 65 ) that extend within and along the length L of the chassis 1204 between the evaporation section 1228 and the condensation sections 1230 and 1232. The first pipe 1234 may be configured to direct a heated working fluid (such as the working fluid described in the previous embodiment) received from the evaporation section 1228 to one of the condensation sections 1230 and 1232 during operation. The second pipe 1236 may be configured to provide a return fluid path for returning the cooled or condensed working fluid from the condensation sections 1230 and 1232 back to the evaporation section 1228 through one of the connecting portions 1231 and 1233, respectively, during operation.

[0117] In one embodiment, the chassis 1204 further includes a heat exchange section 1238 disposed downstream from the evaporation section 1228. The heat exchange section 1238 may include a first heat exchange component 1240 (shown more clearly in FIG. 65 ) and a second heat exchange component 1242 (shown more clearly in FIG. 66 ) that cooperate during operation to heat ambient air (drawn from an air inlet 1246) and cool the heated working fluid received from the evaporation section 1228. As shown, the heat exchange section 1238 may be implemented in the section 1210 of the chassis 1204.

[0118] As shown in FIG. 65 , the heat exchange section 1238 may be configured to be fluidly connected to the second pipe 1236 and the first pipe 1234 via the first valve element 1244 and the second valve element 1250, respectively. For example, the first pipe 1234 may be connected to the upper or second heat exchange component 1242 via the second valve element 1250, which, when actuated, is adapted to direct the heated working fluid in the first pipe 1234 to the heat exchange section 1238 via the fluid inlet 1247. Similarly, the second pipe 1236 is connected to the lower or first heat exchange component 1240 via the first valve element 1244, which, when actuated, is adapted to direct the condensed working fluid collected in the first heat exchange component 1240 to the second pipe 1236 via the outlet 1245. In some embodiments, the first valve element 1244 and / or the second valve element 1250 may be manually or electrically actuated and may be embodied as one-way valves that only allow fluid to flow into and / or out of the heat exchange section 1238. However, other configurations of the valve elements 1244, 1250 may be implemented to achieve similar results. The heat exchange section 1238 may further be fluidly connected to an external environment and may be configured to receive ambient air via an air inlet 1246 therein. The ambient air absorbs heat from the heated working fluid in the heat exchange section 1238 and outputs a cooled or condensed working fluid via an outlet 1245. The heated ambient air is periodically directed to expose each of the actuator bands 1256 or 1258 to heat, as described below.

[0119] In one embodiment, the heat engine 1202 may further include one or more thermal switching mechanisms, such as a first thermal switching mechanism 1248 (shown in FIG. 66) and a second thermal switching mechanism 1276 (shown in FIG. 67), which may be operable to periodically expose the first actuator band 1256 and / or the second actuator band 1258 to heat in order to rotate a work output member, such as an output shaft 1260 (shown in FIG. 67), via a drive assembly 1272. To this end, in one embodiment, as shown in FIG. 66, the first thermal switching mechanism 1248 includes a fan assembly 1262 and an airflow control valve 1264. The fan assembly 1262 includes a first fan and a second fan and is adapted to expose the actuator bands 1256, 1258 to heat by forced convection. The fan assembly 1262 may be configured to draw heated air from the heat exchange section 1238 and direct it to one of the actuator bands 1256, 1258 via the airflow control valve 1264. For example, a first fan of the fan assembly 1262 may draw heated air from the second heat exchange component 1242 and direct it to one of the first tube 1252 or the second tube 1254 carrying the first actuator band 1256 and the second actuator band 1258, respectively. The first tube 1252 and the second tube 1254 may be thermally insulated in some examples to allow the actuator bands 1256, 1258 to absorb heat from the heated air flowing therethrough. Additionally, the second fan of the fan assembly 1262 may be configured to draw ambient air via the ambient air inlet 1268 for directing it to the other of the first tube 1252 and the second tube 1254 via the airflow control valve 1264. The fan assembly 1262, in some examples, is powered by utilizing a portion of the power generated by the heat engine 1202, and in some other illustrative embodiments may be powered by an external power source.

[0120] Additionally, the airflow control valve 1264 may be configured to direct the (cooler and / or hotter) airflow to the first tube 1252 via the first passage 1265 or to the second tube 1254 via the second passage 1266. The airflow control valve 1264 may be automatically controlled to periodically switch between the first and second valve positions at regular intervals. In one example, the airflow control valve 1264 may be a four-way two-position valve, but in other examples, it may be any other type of valve capable of achieving the functionality described herein. For example, in a first valve position, the airflow control valve 1264 may direct a warm airflow (i.e., heated air from the heat exchange section 1238) to the first tube 1252 via a first passageway 1265 to expose the first actuator band 1256 to heat, and may direct cooler ambient air (from the ambient air inlet 1268 of the fan assembly 1262) to the second tube 1254 via a second passageway 1266 to expose the second actuator band 1258 to the cooler air. Similarly, in a second valve position, the airflow control valve 1264 may direct a warm airflow to the second tube 1254 via passageway 1266 to expose the second actuator band 1258 to heat, while directing cooler ambient air to the first tube 1252 via passageway 1265 to expose the first actuator band 1256 to the cooler air.

[0121] In the illustrated example, the actuator bands 1256, 1258 are implemented as prestressed elastomeric bands configured to contract when exposed to heat and expand when cooled. However, other types and configurations of actuator bands 1256, 1258 (including those described in various examples above) can be implemented to achieve similar results. Additionally, the prestressed actuator bands using heavy components described in this example can also be implemented in any of the heat engine configurations according to other embodiments described above, for example, as part of the drive mechanism 7037 (shown in FIG. 40), drive arrangement 8045 (shown in FIG. 51) and / or drive arrangement 9045 (shown in FIG. 56). The actuator bands 1256 and 1258 are fixedly coupled at one end to fixed mounting structures 1269 and 1270 provided on the first tube 1252 and second tube 1254, respectively, in some examples. Additionally, the actuator bands 1256 and 1258 are movably coupled to a drive or work output member 1260 for rotation via a drive assembly 1272 (shown in FIG. 67).

[0122] As shown in FIG. 67, the work output member 1260 is mounted to a mounting assembly 1273, which in turn is coupled to a flange member 1226 of the chassis 1204 by any known suitable fastening mechanism. The mounting assembly 1273 further supports a drive assembly 1272 for rotating the output shaft 1260 in response to contracting and expanding movements of the actuator bands 1256, 1258. The mounting assembly 1273 includes a housing 1274 having a second thermal switching mechanism 1276, such as a fluid flow control valve (hereinafter fluid flow control valve 1276) configured to switch thermal exposure between the actuator bands 1256 and 1258. In some embodiments, either the first thermal switching mechanism 1264 or the fluid flow control valve 1276, or both, may be operable at times to operate the heat engine with or without heat exchanger functionality. For example, when the heat exchange section 1238 is in operation, only the first thermal switching mechanism 1264 is operable, and when the heat engine 1202 is operated without the heat exchange section 1238, only the fluid flow control valve 1276 is operable, cyclically exposing the actuator bands 1256 and 1258 to heat. To operate the heat engine 1202 without the heat exchange section 1238, the second valve element 1250 may be closed to prohibit the heated working fluid in the first pipe 1232 from entering the heat exchange section 1238, thereby directing the entire heated working fluid to one of the condensing sections 1230, 1232. In some additional or alternative embodiments, the thermal switching mechanism 1248 and the fluid flow control valve 1276 may be operably connected to switch the thermal exposure between the actuator bands 1256 and 1258. The fluid flow control valve 1276 may be actuated by a valve actuation system (not shown) and may be configured to be in a first valve position that exposes the first actuator band 1256 to heat and in a second valve position that exposes the second actuator band 1258 to heat in a manner similar to that described above in the other illustrative embodiments.

[0123] Additionally, the mounting assembly 1273 includes a central support tube 1278 coupled at one end to a mounting plate 1280 and supporting a generator housing 1282 at the other end. The generator housing 1282 can house a gearbox, a generator system (such as system 104 of FIG. 1), a power conditioning system (such as system 106 of FIG. 1), etc. for receiving the rotation of the output shaft 1260 as an input for generating electrical power in a manner similar to that described above. The drive assembly 1272 includes a first movable mounting structure 1284 for movably mounting the first actuator band 1256 and a second movable mounting structure 1286 for movably mounting the second actuator band 1258 thereto. As shown, each of the first movable mounting structure 1284 and the second movable mounting structure 1286 may be a U-shaped structure having two open ends that are secured to a respective movable plate (e.g., secured to the first movable plate 1288 and the second movable plate 1290), which in turn are also secured to the first actuator band 1256 and the second actuator band 1258, respectively.

[0124] Additionally, the drive assembly 1272 includes a first drive bar 1292 coupled to a first movable mounting structure 1284, which is operably coupled to the first actuator band 1256, and a second drive bar 1294 coupled to a second movable mounting structure 1286, which is operably coupled to the second actuator band 1258. To this end, the mounting plate 1280 may include through holes that allow the drive bars 1292, 1294 to pass therethrough and be coupled to the respective movable mounting structures 1284, 1286. In an exemplary embodiment, the drive assembly 1272 further includes a first weight bar 1296 and a second weight bar 1300, the first weight bar 1296 having a first weight component 1298 and operably coupled to the first drive bar 1292, and the second weight bar 1300 having a weight component 1302 and operably coupled to the second drive bar 1294.

[0125] The mounting assembly 1273 further includes a first holder 1304 having a first end for rotatably supporting the first drive bar 1292 and the first weight bar 1296 and a second end for rotatably supporting the second drive bar 1294 and the second weight bar 1300. The first holder 1304 further supports a fixed non-rotating shaft 1308 that is coupled to the drive bars 1292, 1294 and the weight bars 1296, 1300 by respective gear assemblies 1310 (only one shown). Each of the gear assemblies 1310 may include a respective gear disposed on a bearing to allow freedom of movement of the gear. Thus, the gear assemblies 1310 accommodate linear movement of the bars without rotating the shaft 1308 during operation.

[0126] The mounting assembly 1273 further includes a second holder 1312 having a first end for movably supporting the first drive bar 1292 and the first weight bar 1296 and a second end for movably supporting the second drive bar 1294 and the second weight bar 1300. The second holder 1312 also rotatably supports the output shaft 1260 therein. In one example, the output shaft 1260 can include two independent integrated coaxial shafts. The output shaft(s) 1260 can be rotatably engaged with the drive bars 1292, 1294 and the weight bars 1296, 1300 by respective gear assemblies 1314 (only one shown) having bevel and / or non-bevel gears supported in unidirectional rotary bearings to convert bidirectional rotation of the output shaft(s) 1260 to unidirectional rotation. In some embodiments using non-bevel gears, the rotor axis of the motor-generator housed in the generator housing 1282 may be non-parallel to the weight bars 1296 and 1300. In some examples, the drive bars 1292, 1294 and the weight bars 1296, 1300 may each include respective internal gear teeth (not shown), e.g., extending along a portion of their respective lengths, for mating with the gear assemblies 1310, 1314. Similarly, the drive bars 1292, 1294 and the weight bars 1296, 1300 may also each include respective external gears (not shown), e.g., extending along a portion of their respective lengths, for mating with corresponding gears provided at each end of the first holder 1304 and the second holder 1312.

[0127] In a first mode of operation using the heat exchange section 1238, a first thermal switching mechanism 1248 may be utilized. To this end, heated working fluid from the evaporation section 1228 is received in the pipe 1234. In one embodiment, the valve elements 1244, 1250 may be actuated to direct the heated working fluid to the heat exchange section 1238. The air inlet 1246 of the heat exchange section 1238 also draws in ambient air which is heated by the heated working fluid flowing through the heat exchange section 1238. In a first cycle of operation, in this example, the valve position of the airflow control valve 1264 is set to a first valve position to direct heated air from the heat exchange section 1238 to the first tube 1252 and cooler ambient air to the second tube 1254. Similarly, in this example, in a second operating cycle, the airflow control valve 1264 is switched to a second valve position to direct heated air from the heat exchanger to the second tube 1254 and cooler ambient air to the first tube 1252. As previously explained, when in the first valve position, the airflow control valve 1264 directs heated air from the heat exchange section 1238 via passage 1265 to the first tube 1252 to expose the first actuator band 1256 to heat, and simultaneously directs cooler ambient air drawn from the inlet 1268 of the fan assembly 1262 via passage 1266 to the second tube 1254 to expose the second actuator band 1258 to the cooler air. Similarly, when in the second valve position, the airflow control valve 1264 directs heated air from the heat exchange section 1238 via passage 1266 to the second tube 1254 to expose the second actuator band 1258 to heat, and simultaneously directs cooler ambient air from the fan assembly 1262 via passage 1265 to the first tube 1252 to expose the first actuator band 1256 to the cooler air.

[0128] In another additional or alternative mode of operation that does not utilize the heat exchange section 1238, only the fluid flow control valve 1276 is operable. This involves the second valve element 1250 being closed to direct the heated working fluid from the evaporation section 1228 to either the first condensing section 1230 and respective first tube 1252 or the second condensing section 1232 and respective second tube 1254, based on the position of the fluid flow control valve 1276, in a manner similar to that described above. Thus, in the first valve position of the fluid flow control valve 1276, the heated working fluid is directed to the first condensing section 1230, thereby exposing the first actuator band 1256 to heat. Similarly, in the second valve position, the heated working fluid is directed to the second condensing section 1232, thereby exposing the second actuator band 1258 to heat. In such an embodiment, the heated working fluid transfers heat to the respective actuator bands 1256 and 1258 by conduction instead of forced convection.

[0129] In some additional or alternative embodiments, the first thermal switching mechanism 1248 and the second thermal switching mechanism (i.e., fluid flow control valve) 1276 may be operatively connected and configured to cooperate to periodically expose the actuator bands 1256 and 1258 to heat. For example, when the fluid flow control valve 1276 is switched to a first valve position, the airflow control valve 1264 is also switched to a first valve position, exposing the first actuator band 1256 to heat and exposing the second actuator band 1258 to cooler ambient air, and when the fluid flow control valve 1276 is switched to a second valve position, the airflow control valve 1264 is also switched to a second valve position, exposing the second actuator band 1258 to heat and exposing the first actuator band 1256 to cooler ambient air. In some embodiments, when the first thermal mechanism 1247 and the second thermal mechanism 1276 cooperate, the valve elements 1250 and 1244 can be controlled to allow a portion of the heated working fluid in the pipe 1234 to be directed to both the heat exchange section 1238 and one of the condensation sections 1230, 1232. Thus, the actuator bands 1256, 1258 can be exposed to heat by both conduction from the respective condensation sections 1230, 1232 and by forced convection from the respective tubes 1252, 1254 via the fan assembly 1262.

[0130] In operation, when one of the actuator bands 1256 or 1258 is exposed to heat, the other is simultaneously exposed to cold, causing one actuator band (exposed to heat) to contract and the other actuator band (exposed to cold) to expand. When one of the actuator bands 1256 or 1258 contracts, the corresponding U-shaped movable mounting member 1284 or 1286 is pulled downward, and when the other of the actuator bands 1256 or 1258 expands, the corresponding U-shaped movable mounting member 1284 or 1286 moves upward. When the U-shaped movable mounting member 1284 or 1286 is pulled downward, the corresponding one of the drive bars 1292, 1294 is also pulled downward by the gear assemblies supported by the first and second holders 1304, 1312, respectively. The corresponding weight bars 1296, 1300 are similarly constrained to move upwardly and downwardly by gear assemblies supported on holders 1304, 1312. In some embodiments, the weight components 1298 and 1302 are adapted to provide a downward force through the respective weight bars 1296 and 1300 to counteract the downward movement of the drive bars 1292 and 1294 and pull them back upwardly. The countervailing force provided by the weight components 1298 and 1302 allows the prestress force required to effectively actuate the actuator bands 1256 and 1258 to be maintained.

[0131] Upon actuation of the actuator bands 1256, 1258, the drive bars 1292, 1294 and weight bars 1296, 1300 cause bidirectional rotation of the work output member 1260. As previously described, the work output member 1260 is mounted to a number of unidirectional rotational bearings and bevel gears arranged to convert the bidirectional rotation of the shaft 1260 into unidirectional rotation that is supplied to the generator housing 1282. The housing 1282 may include an appropriate mechanism for increasing the speed of the unidirectional rotation required to generate electrical power.

[0132] The heat engine 1202 utilizes forced convection using the fan assembly 1262 to heat and / or cool the actuator bands 1256, 1258. By using forced convection, the actuator bands 1256, 1258 can be heated and cooled faster, thereby reducing the cycle of operation time of the actuator bands 1256, 1258 and increasing the power generation capacity and efficiency of the heat engine 1202. The fan assembly 1262 can be operated using a small portion of the power generated by the heat engine itself or by using an external power source. Thus, by adding an additional fan assembly to a heat engine, the overall mechanical power extracted from such a heat engine is increased. This arrangement therefore effectively reduces the time required to convert thermal energy into electrical power. Furthermore, the weight components 1298, 1302 provide a low-cost and effective means to impart the necessary prestress to the actuator bands 1256, 1258.

[0133] It will be appreciated that the construction and configuration of the heat engine 1202 described above is merely exemplary, and the concepts presented can be applied to other configurations of heat engines to achieve similar results.

[0134] For simplicity and clarity of illustration, reference numerals may be repeated between figures to indicate corresponding or similar elements, where considered appropriate. Additionally, numerous specific details are described to provide a thorough understanding of the examples described herein. However, those skilled in the art will appreciate that the examples described herein may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the examples described herein. Furthermore, this specification is not to be considered as limiting the scope of the examples described herein.

[0135] It will be understood that the examples and corresponding figures used herein are for illustrative purposes. Different configurations and terminology may be used without departing from the principles set forth herein. For example, components and modules may be added, removed, modified, or arranged in different connections without departing from these principles.

[0136] The steps or operations of the flow charts and diagrams described herein are merely exemplary. There may be many variations in these steps or operations without departing from the principles described above. For example, steps may be performed in a different order, or steps may be added, deleted, or modified. Although the above principles have been described with reference to specific examples, various modifications thereof will be apparent to those skilled in the art. [Brief description of the drawings]

[0137] [Figure 1] FIG. 1 is a simplified schematic diagram of a power generation system according to one aspect of the present disclosure. [Diagram 2] 1 shows a heat engine according to a first embodiment of the present disclosure; [Diagram 3] 1 shows a heat engine according to a first embodiment of the present disclosure; [Figure 4] 1 shows a heat engine according to a first embodiment of the present disclosure; [Diagram 5] 1 shows a heat engine according to a first embodiment of the present disclosure; [Figure 6] 1 shows a heat engine according to a first embodiment of the present disclosure; [Figure 7] 1 shows a heat engine according to a first embodiment of the present disclosure; [Figure 8] 1 shows a heat engine according to a first embodiment of the present disclosure; [Figure 9] 1 shows a heat engine according to a first embodiment of the present disclosure; [Figure 10] 2 shows a heat engine according to a second embodiment. [Figure 11] 2 shows a heat engine according to a second embodiment. [Figure 12]2 shows a heat engine according to a second embodiment. [Figure 13] 2 shows a heat engine according to a second embodiment. [Figure 14] 3 shows a heat engine according to a third embodiment. [Figure 15] 3 shows a heat engine according to a third embodiment. [Figure 16] 3 shows a heat engine according to a third embodiment. [Figure 17] 3 shows a heat engine according to a third embodiment. [Figure 18] 3 shows a heat engine according to a third embodiment. [Figure 19] 3 shows a heat engine according to a third embodiment. [Figure 20] 3 shows a heat engine according to a third embodiment. [Figure 21] 3 shows a heat engine according to a third embodiment. [Figure 22] 4 shows a heat engine according to a fourth embodiment. [Diagram 23] 4 shows a heat engine according to a fourth embodiment. [Figure 24] 4 shows a heat engine according to a fourth embodiment. [Diagram 25] 4 shows a heat engine according to a fourth embodiment. [Figure 26] 4 shows a heat engine according to a fourth embodiment. [Figure 27] 5 shows a heat engine according to a fifth embodiment. [Figure 28] 5 shows a heat engine according to a fifth embodiment. [Figure 29] 5 shows a heat engine according to a fifth embodiment. [Diagram 30] 5 shows a heat engine according to a fifth embodiment. [Diagram 31] 5 shows a heat engine according to a fifth embodiment. [Diagram 32] 6 shows a heat engine according to a sixth embodiment. [Diagram 33] 6 shows a heat engine according to a sixth embodiment. [Diagram 34] 6 shows a heat engine according to a sixth embodiment. [Diagram 35] 6 shows a heat engine according to a sixth embodiment. [Diagram 36] 6 shows a heat engine according to a sixth embodiment. [Figure 37] 13 shows a heat engine according to a seventh embodiment. [Figure 38] 13 shows a heat engine according to a seventh embodiment. [Figure 39] 13 shows a heat engine according to a seventh embodiment. [Diagram 40] 13 shows a heat engine according to a seventh embodiment. [Diagram 41] 13 shows a heat engine according to a seventh embodiment. [Diagram 42] 13 shows a heat engine according to a seventh embodiment. [Diagram 43] 13 shows a heat engine according to a seventh embodiment. [Diagram 44] 1 shows a heat engine according to aspect 1 of the eighth embodiment. [Diagram 45] 1 shows a heat engine according to aspect 1 of the eighth embodiment. [Figure 46] 1 shows a heat engine according to aspect 1 of the eighth embodiment. [Figure 47] 1 shows a heat engine according to aspect 1 of the eighth embodiment. [Figure 48] 1 shows a heat engine according to aspect 1 of the eighth embodiment. [Figure 49] 1 shows a heat engine according to aspect 1 of the eighth embodiment. [Figure 50] 1 shows a heat engine according to aspect 1 of the eighth embodiment. [Figure 51] 1 shows a heat engine according to aspect 1 of the eighth embodiment. [Figure 52] 13 shows a heat engine according to aspect 2 of the eighth embodiment. [Figure 53] 13 shows a heat engine according to aspect 2 of the eighth embodiment. [Figure 54]13 shows a heat engine according to aspect 2 of the eighth embodiment. [Figure 55] 13 shows a heat engine according to aspect 2 of the eighth embodiment. [Figure 56] 13 shows a heat engine according to aspect 2 of the eighth embodiment. [Figure 57] 13 shows a heat engine according to aspect 3 of the eighth embodiment. [Figure 58] 13 shows a heat engine according to aspect 3 of the eighth embodiment. [Figure 59] 13 shows a heat engine according to aspect 3 of the eighth embodiment. [Figure 60] 9 shows a heat engine according to a ninth embodiment, which utilizes solar thermal energy for its operation. [Figure 61] 9 shows a heat engine according to a ninth embodiment, which utilizes solar thermal energy for its operation. [Figure 62] 9 shows a heat engine according to a ninth embodiment, which utilizes solar thermal energy for its operation. [Figure 63] 13 shows a heat engine according to a tenth embodiment. [Figure 64] 13 shows a heat engine according to a tenth embodiment. [Figure 65] 13 shows a heat engine according to a tenth embodiment. [Figure 66] 13 shows a heat engine according to a tenth embodiment. [Figure 67] 13 shows a heat engine according to a tenth embodiment.

Claims

1. a chassis for supporting one or more heat engine components; a work output member supported by the chassis and adapted to generate and output mechanical power to a power generation system for generating electrical power; an actuation mechanism coupled to and adapted to actuate the work output member to generate the mechanical power; The actuation mechanism includes: a first actuator band array operatively connected to the work output member and adapted to displace the work output member in a first direction in response to thermal exposure; a second actuator band array operatively connected to the work output member and adapted to displace the work output member in a second direction in response to thermal exposure; a thermal switching mechanism operable to cyclically expose each of the first actuator band array and the second actuator band array to heat to cause cyclic displacement of the work output member in the first direction and the second direction to generate the mechanical power.

2. one or more of the first actuator band array and the second actuator band array include one or more actuator bands; 10. The heat engine of claim 1, wherein each of the one or more actuator bands is made from a material having a high coefficient of thermal expansion or contraction and adapted to change dimensions in response to thermal exposure.

3. 3. The heat engine of claim 2, wherein one or more actuator bands in each of the first actuator band array and the second actuator band array are stretch elastomeric bands adapted to change a respective length in response to thermal exposure.

4. 3. The heat engine of claim 2, wherein one or more actuator bands in each of at least one of the first actuator band array and the second actuator band array are made from one of rubber, silicone based rubber, polyurethane, styrene butadiene copolymer, natural rubber, and an elastomer.

5. the chassis includes a first longitudinal end and a second longitudinal end; the work output member is supported at least at the first longitudinal end; 2. The heat engine of claim 1, wherein each of the first actuator band array and the second actuator band array is supported between the first longitudinal end and the second longitudinal end and operably connected to the work output member at the first longitudinal end.

6. 6. The heat engine of claim 5, wherein the thermal switching mechanism is supported at one or more of the first longitudinal end and the second longitudinal end of the chassis.

7. The actuation mechanism includes: a gear assembly supported by the chassis and adapted to rotate the work output member; the gear assembly includes a driving member and a driven member supporting the work output member thereon; the first actuator band array is operatively connected to a first end of the drive member; the second actuator band array is operatively connected to a second end of the drive member; each of at least one of the first and second actuator band arrays adapted to periodically displace the drive member in one of a first and a second direction to rotate the driven member when periodically exposed to heat; 2. The heat engine of claim 1, wherein said rotation of said driven member causes rotation of said work output member supported thereon.

8. 8. The heat engine of claim 7, wherein said driving member is a linear rack gear and said driven member is a pinion gear.

9. the actuation mechanism includes a band attachment member supported on one longitudinal end of the chassis; 2. The heat engine of claim 1, wherein the band attachment member includes a first end that receives and secures one end of the first actuator band array and a second end that receives and secures one end of the second actuator band array thereto.

10. 10. The heat engine of claim 9, wherein the other end of each of the first actuator band array and the second actuator band array are joined to form a continuous loop.

11. 10. The heat engine of claim 9, wherein the other end of each of the first actuator band array and the second actuator band array is fixed to the other longitudinal end of the chassis.

12. the chassis includes a box-like structure having an upper frame and a lower frame that define a height of the chassis; 2. The heat engine of claim 1, wherein the first actuator band array and the second actuator band array each include a plurality of actuator bands arranged in layers to extend through the height of the chassis.

13. the chassis includes a box-like structure having an upper frame and a lower frame that define a height of the chassis; 2. The heat engine of claim 1, wherein the first actuator band array and the second actuator band array each include an actuator band having a height equal to the height of the chassis.

14. located in a facility having a first environment having a first environmental temperature and a second environment having a second environmental temperature lower than the first environmental temperature; 2. The heat engine of claim 1, wherein the thermal exposure is provided to the first actuator band array and the second actuator band array as a temperature gradient between the first temperature and the second temperature.

15. 10. The heat engine of claim 1, wherein the heat exposure is provided from a heat source comprising one or more of a low temperature waste heat source, a solar thermal energy source, a geothermal energy source, and natural heat resources including heat derived from one or more of the ground, air, and water.

16. 16. The heat engine of claim 15, wherein the solar thermal energy source includes one or more of an evacuated glass tube and a Miller-wise collector for collecting solar thermal energy.

17. each of the first actuator band array and the second actuator band array is supported by a plurality of band contact assemblies attached to the chassis; 10. The heat engine of claim 1, wherein each of the plurality of band contact assemblies includes one or more pulleys mounted on a shaft arrangement and supported in one or more bearings.

18. the plurality of band contact assemblies include a first set of band contact assemblies rotatable in a first rotational direction and a second set of band contact assemblies rotatable in a second rotational direction; 20. The heat engine of claim 17, wherein the first direction of rotation and the second direction of rotation are configured to cooperate to produce unidirectional rotation of a work output member.

19. the one or more bearings include a one-way rolling bearing; 20. The heat engine of claim 17, wherein the first actuator band array and the second actuator band array are adapted to generate unidirectional rotation of the work output member when supported on the unidirectional rotation bearing.

20. the one or more bearings include a free-spinning bearing; 18. The heat engine of claim 17, wherein the first actuator band array and the second actuator band array are adapted to generate bidirectional rotation of the work output member when supported on the free rotating bearings and when at least one end of each of the first actuator band array and the second actuator band array is fixed to the chassis.

21. the thermal switching mechanism includes a flow control valve adapted to switch a valve position to direct heat to one of the first actuator band array and the second actuator band array; 2. The heat engine of claim 1, wherein each of the first actuator band array and the second actuator band array are cyclically exposed to heat by cyclically switching the valve position of the flow control valve.

22. the actuation mechanism includes a heat exchanger fluidly connected to a heat source and to the thermal switching mechanism; the heat exchanger includes a first heat exchange section having a working fluid for absorbing heat from a heat source; The heat engine of claim 1 , wherein the heated working fluid is adapted to expose the first actuator band array and the second actuator band array to heat.

23. Located in a facility having a first environment having a first environmental temperature and a second environment having a second environmental temperature lower than the first environmental temperature; 23. A heat engine as claimed in claim 22, wherein the first heat exchange section is disposed in the first environment having the first environmental temperature.

24. the actuation mechanism includes a heat exchanger fluidly connected to a heat source and to the thermal switching mechanism; 2. The heat engine of claim 1, wherein the heat exchanger includes a second heat exchange section adapted to expose the first actuator band array supported therein to heat, and a third heat exchange section adapted to expose a second actuator band array supported therein to heat in response to a position of a thermal switching mechanism.

25. Located in a facility having a first environment having a first environmental temperature and a second environment having a second environmental temperature lower than the first environmental temperature; 25. A heat engine as claimed in claim 24, wherein the second heat exchange section and the third heat exchange section are disposed in the second environment.

26. the chassis includes a first arm and a second arm spaced apart to define a length of the chassis; the work output member includes a rotatable shaft having one end connected to the first arm and a second end connected to the second arm; 2. The heat engine of claim 1, wherein the actuation mechanism comprises a rotating cylinder rotatably supported on the shaft and including a first longitudinal section adapted to mount the first actuator band array thereon and a second longitudinal section adapted to mount the second actuator array thereon.

27. 27. The heat engine of claim 26, wherein a first end of each of the first and second actuator band arrays is operably coupled to the shaft at one of the first or second arms via a respective drive mechanism adapted to rotate the shaft in response to cyclical thermal exposure of the first and second actuator band arrays.

28. each of the first actuator band array and the second actuator band array includes at least one first actuator band and at least one second actuator band; The drive mechanism includes: a first chain and sprocket arrangement adapted to movably connect one end of each of the first actuator band and the second actuator band to the rotating cylinder and the first arm; and a second chain and sprocket arrangement movably connecting the other end of the second actuator band to the rotating cylinder and to the second arm.

29. each of the first and second chain and sprocket arrangements is connected to a fixed bevel gear on each of the respective first and second arms of the chassis by an arrangement including a drive shaft, a set of unidirectional rolling bearings, and a rolling gear member; 29. A heat engine as claimed in claim 28, wherein the set of unidirectional rolling bearings are adapted to rotate the shaft and the rotating gear member in one direction.

30. The drive assembly includes: a fastening mechanism adapted to secure one end of the first actuator band to the rotating cylinder; a guide bar secured to the fastening mechanism and to the second chain sprocket arrangement; 28. The heat engine of claim 27, wherein the guide bar is adapted to support a spring member adapted to enable movement of the first and second actuator bands in each of the first and second actuator band arrays in response to the thermal exposure.

31. the actuation mechanism includes a plurality of heat engine cylinders supported by the chassis; 2. The heat engine of claim 1, wherein the first actuator band array and the second actuator band array are disposed on an exterior surface of each of the plurality of heat engine cylinders.

32. 32. A heat engine as described in claim 31 , wherein the actuation mechanism includes a thermal switching mechanism coupled to each one of the plurality of heat engine cylinders.

33. the chassis being a cylindrical structure having the work output member rotatable therein; The chassis includes: a lower portion fluidly coupled to a heat source via an evaporative section; a top portion including a first set of support arms extending radially outward above the top portion and a second set of support arms extending radially outward below the top portion; 32. A heat engine as described in claim 31 , wherein the first set of support arms and the second set of support arms are adapted to mount a respective one of the heat engine cylinders thereon.

34. Each of the plurality of heat engine cylinders includes a thermally insulating inner cylindrical shell and a thermally conductive outer cylindrical shell defining a fluid passage space therebetween; the outer cylindrical shell is in contact with the first actuator band array and the second actuator band array disposed on the outer surface of each of the heat engine cylinders; 32. The heat engine of claim 31 , wherein a heated working fluid is received in the fluid passage space exposing the first actuator band array and the second actuator band array disposed on the exterior surface to heat from the heated working fluid.

35. the chassis being a cylindrical structure having the work output member rotatable therein; each of the first actuator band array and the second actuator band array includes a plurality of actuator bands operatively connected to the work output member by an arrangement including a first fixed flange member, a second fixed flange member, and a drive arrangement; the first fixing flange member is provided at a first longitudinal end of each of the plurality of heat engine cylinders and adapted to secure a first end of each of the plurality of actuator bands; the second fixed flange member is provided at a second longitudinal end of each of the plurality of heat engine cylinders and is adapted to support a gear arrangement for rotating the work output member; 32. The heat engine of claim 31 , wherein the drive arrangement movably couples a second end of each of a plurality of the actuator bands to a gear arrangement.

36. The drive arrangement comprises: a movable flange member disposed between the first fixed flange member and the second fixed flange member and adapted to movably secure a second end of each of the plurality of actuator bands; a drive gear member having one end connected to the movable flange member and another end connected to a gear arrangement via the second fixed flange member; the movable flange member and the drive gear member adapted to move linearly in response to expansion or contraction of the actuator band due to thermal exposure; 36. A heat engine as described in claim 35, wherein the linear movement of the linear gear member causes rotation of the gear arrangement and the work output member.

37. The drive gear member is further operatively coupled to a spring guide rod by a movable fastening mechanism; 37. A heat engine as claimed in claim 36, wherein said spring guide rod is fixedly connected to said second fixed flange member.

38. The drive arrangement comprises: a movable flange member disposed between the first fixed flange member and the second fixed flange member and adapted to movably secure a second end of each of the plurality of actuator bands thereto; a chain and sprocket arrangement operatively coupled to the gear arrangement for rotating the work output member; the chain and sprocket arrangement includes a chain member; 36. A heat engine as described in claim 35, wherein the chain member is rotatably supported on a sprocket supported on the second fixed flange member and is connected at one end to the movable flange by a fastening rod and at the other end to a spring guide rod, the spring rod adapted to be fixedly coupled to the second fixed flange member.

39. the chassis includes a plurality of sections; The actuation mechanism includes: a heat exchange section disposed in one of the plurality of sections and adapted to receive a heated working fluid for heating a first flow of ambient air therein; a fan assembly having an ambient air inlet for receiving a second flow of ambient air therein; the fan assembly is adapted to direct the first heated flow of ambient air towards one of the first and second actuator band arrays and direct the second flow of ambient air towards the other of the first and second actuator band arrays via an airflow control valve; 2. The heat engine of claim 1, wherein the airflow control valve is operable to control each of the first flow of heated ambient air and the second flow of heated ambient air to be directed towards one of the first actuator band array and the second actuator band array.

40. the actuation mechanism includes a drive assembly adapted to operably connect the work output member to the first actuator band array and the second actuator band array; The drive assembly includes: a first movable mounting structure and a second movable mounting structure supported by the chassis and adapted to movably connect to the first actuator band array and the second actuator band array, respectively; a first drive bar and a second drive bar connected to the first moveable mounting structure and the second moveable mounting structure, respectively; a first weight bar and a second weight bar coupled to the first drive bar and the second drive bar, respectively; 40. The heat engine of claim 39, wherein the first and second drive bars and the first and second weight bars are adapted to rotatably engage the work output member and enable rotation of the work output member in response to displacement of each of the first and second actuator band arrays in response to thermal exposure.

41. A power generation system for generating electric power; a heat engine operably coupled to the power generation system; The heat engine comprises: a chassis for supporting one or more heat engine components; a work output member supported by the chassis and adapted to generate and output mechanical power to the power generation system; an actuation mechanism coupled to and adapted to actuate the work output member to generate the mechanical power; The actuation mechanism includes: a first actuator band array operatively connected to the work output member and adapted to displace the work output member in a first direction in response to thermal exposure; a second actuator band array operatively connected to the work output member and adapted to displace the work output member in a second direction in response to thermal exposure; a thermal switching mechanism operable to cyclically expose each of the first actuator band array and the second actuator band array to heat to cause cyclic displacement of the work output member in the first direction and the second direction to generate the mechanical power.

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