2 3 4 5

6 Technical Field

7 This invention relates to a liquid piston heat engine or heat pump using a Stirling cycle * 8 engine design and having a multiple cylinder array which is capable of producing rotary motion.

9

10 Background Art

11 In 1816 a Scottish clergyman by the name of Robert Stirling invented a heat engine for a

12 source of mechanical power wherein a gas-filled cylinder is alternately heated and cooled for moving

13 a piston back and forth from one end of the cylinder to the other end of the cylinder. The Stirling

14 engine competed with the steam engine, before both were displaced by the internal combustion

15 engine at the start of the twentieth century. Today a great deal of research is being conducted using

16 the Stirling engine cycle design, not as an engine, but for example as a refrigeration heat pump for

17 refrigerators. Helium, a gas which is inert and nontoxic, is being used in the current Stirling pump

18 research. If the new Stirling engine refrigeration designs are successful the use of ozone depleting

19 chlorofluorocarbons (CFC's) would be eliminated. CFC's used as a refrigerant were introduced in

20 1931 by DuPont Co. under the trademark Freon. CFC's and substitutes thereof are expensive and

21 are believed to be harmful to our environment.

22 In the early 1970's Colin D. West, a leading authority on Stirling engine technology,

23 disclosed a Stirling cycle liquid piston engine activated by a heated and cooled gas which could be

24 used as a simple, low cost, heat pump. This Stirling cycle liquid piston design is known as the

25 "Siemens" arrangement. By using a multi-cylinder configuration of this arrangement, which is

26 referred to as a "fluidyne", a system can be designed in which all liquid columns are subject to both

27 gas-pressure as well as gravity. West's work related to Stirling cycle heat engines is well

28 documented in numerous published articles as well as in British Patents 1,487,332; 1,507,678;

29 1,329,567; 1,568,057; 1,581,748; and 1,581,749.

30 In U.S. Patent 4,130,993 to Erazo and U.S. Patent 4,134,264 to Baer variations of the

31 Siemens arrangement using a Stirling heat engine or heat pump are described wherein an oscillating

32 liquid motion in a plurality of cylinders produces rotational motion. The Erazo and Baer engines,

33 when rotated on an axis beyond the centrifugal velocity of the oscillating liquid, and with heating

34 and cooling supplied to the system, the rotary motion of the engines on the axis is sustained. Both v

35 of these engines rotate about a concentric axis which is used for rotary power, which is useful for

36 example for generating electricity and the like.

37 The above mentioned adaptations of the Stirling cycle all have a shortcoming in that their

38 designs provide only a limited surface area on the cylinders which inherently limits heat transfer

39 capability. Also and more importantly none of these known earlier engine designs provide the

40 advantage of using multiple cylmder arrays which are offset from a rotating axis for increased

41 moment force in sustaining rotatable velocity of the system.

None of the above mentioned patents describe or disclose teachings of a unique heat engine or heat pump for producing rotary motion incorporating a Stirling cycle with liquid piston as described herein.

DISCLOSURE OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide an improved liquid piston heat engine which is simple in design, inexpensive to manufacture, and which can be used to efficiently and economically produce rotary motion as a mechanical power source. Another object of the present invention is to provide an engine or pump which can be driven by sources of energy such as hot or cold waste water, hot waste gases, solar energy and the like to produce mechanical motion which can be converted to low cost, clean energy and thereby help reduce dependence on fossil fuels as an energy source. A further object of the present invention is to provide an engine which can be driven by liquids and gases which are inert, and non-toxic and non-harmful to the environment, and thereby, for example, eliminate the use CFC's which are expensive, and which may have a detrimental effect on the earth's protective ozone layer. Still another object of the present invention is the incorporation of the Stirling engine design features with the Siemens arrangement to produce an engine that can provide continuous rotary motion using inexpensive exterior heating and cooling source such as waste water and solar energy. The present invention includes a liquid piston heat engine, which may be used for producing rotary motion. The liquid piston heat engine uses a Stirling cycle heat engine design, wherein a cold exchanger section of a cylinder and a hot exchanger section of the same cylinder are attached to an axis, but positioned off-center with respect to that axis. When used with a rotating axis, a liquid within a portion of the cylinder acts as a piston moves within the bore of the cylinder against the centrifugal field produced by the rotation of the system, and is driven by a working gas which is in the same cylinder. By oscillating the liquid in the cylinder outwardly in the cylinder during a downward power stroke and inwardly during an upward drag stroke, the center of mass of the liquid is further from the axis during the downward power stroke than during the upward drag stroke, thereby providing a greater moment of force during the power stroke, thereby sustaining continuous power producing rotary motion. In order to cause the liquid in the cylinder to thus oscillate, portions of the cylinder are utilized as a cold exchanger section and as a hot exchanger section, the cold exchanger section and the hot exchanger section of the cylinder may be cooled and heated using hot or cold waste water, heated gases, solar energy, or any other type of exterior cooling and heating source- The engine of the present invention may include both a top and bottom cylinder on a common axis, or multiple cylinder arrays, and embodiments of the engine may include a plurality of cylinders disposed and spaced around and attached to a common axis. As used herein, the term "cylinder" is used to refer to a fluid containing chamber, and is not limited to any specific geometric shape. While the cylinder shown in the present application are in

a generally "J" shape to provide a "trap"for the liquid piston portion, other shapes of cylinders may be used to produce an equivalent result. Even a "straight'' cylinder without a trap may be used, for example, in systems which will be caused to experience high revolutions per minute, or large differentials between the temperature at the heat exchanger section and the cold heat exchanger section. These and other objects of the present invention will become apparent to those skilled in the art from the following detailed description, showing the contemplated novel construction, combination, and elements as herein described, and more particularly defined by the appended claims, it being understood that changes in the precise embodiments to the herein disclosed invention are meant to be included as coining within the scope of the claims, except insofar as they may be precluded by the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate complete preferred embodiments of the present invention according to the best modes presently devised for the practical application of the principles thereof, and in which: FIG. 1 is a front view of a prior art multi-cylinder fluidyne heat engine and known as the Siemens arrangement using the Stirling engine technology but with a liquid piston and a working gas. FIG. 2 is a front view of the subject invention having a single cylinder array off-set and rotating about an axis. FIG. 3 is a front view of another embodiment of the invention having an upper and lower cylinder array disposed 180 degrees from each other on the rotating axis. FIG. 4 is an end view of the subject liquid piston heat engine shown in FIG. 3 with the upper cylinder array at a 45 degree position from the vertical or 1:250 o'clock position and the lower cylinder array also at a 45 degree position from the vertical but at a 7:30 o'clock position. F1G.5A through F1G.5H illustrate the position of a liquid center of mass in the upper cylinder as the upper cylinder array rotates from a 12:00 o'clock position, a 1:30 o'clock position, a 3:00 o'clock position, a 4:30 o'clock position, a 6:00 o'clock position, a 7:30 o'clock position, a 9:00 o'clock position, and a 10:30 o'clock position. FIG. 6 illustrates a total cycle of the top cylinder rotating 360 degrees with the area of power during the power stroke in dark shading and the area of drag during the drag stroke unshaded. FIG. 7A through FIG. 7H illustrate the position of liquid center of mass in the lower cylinder as the lower cylinder array rotates from a 12:00 o'clock position, a 1:30 o'clock position, a 3:00 o'clock position, a 4:30 o'clock position, a 6:00 o'clock position, a 7:30 o'clock position, a 9:00 o'clock position, and a 10:30 o'clock position. FIG. 8 is a perspective view of the subject liquid piston heat engine with three cylinder arrays attached to a rotating axis and disposed 120 degrees from each other. FIG. 9 is a perspective view of a portion of one of the cylinders wherein the cylinder is constructed of a stamped sheet conductive metal such as aluminum or copper. Also nonconductive material

such as graphite composites, plastic sheeting, rubber, laminates, and the like may be used in the construction of the cylinders. FIG. 10 illustrates an alternate embodiment of the subject invention having a plurality of cylinder arrays of different lengths and sizes for improved temperature differential. FIG. 11 is a similar view of the subject invention shown in FIG. 3 but used in conjunction with -. walled partitions for cooling and heating an area. FIG. 12 illustrates a sine wave which is used to represent a oscillating frequency of one of the liquid pistons in the engine's cylinder arrays. FIG. 13 illustrates a frequency phase of four different cylinder arrays used with the heat engine- FIG. 14 is a cut-away front view of subject invention similar to the heat engine shown in FIG. 10 having a plurality of cylinder arrays of different lengths and sizes for improved temperature differential, and surrounded by a pressurized vessel to improve the efficiency of the engine. FIGS. 14A, 14B, 14C and 14D illustrate the use of heat pipes, cold pipes, hot sections, cold sections, and inert gas supply lines used with the engine and external pressurized vessel shown in FIG. 14. FIG. 15 shows the use of heat exchangers and cold exchangers with the hot and cold sections of the engine cylinders. FIGS. 16A and 16A illustrate a plurality of engine cylinders carried on a flexible housing and used in a serpentine array, and incorporating the novel features of the subject heat engine. FIGS. 17A, 17B and 17C show the use of drain tubes used with the engine cylinder arrays for controlling the level of the fluid within the engine during shut down and start up of the heat engine. ^• FIGS. 18A, 18B, 18C, 19A, 19B and 19C illustrate various views of the fabrication of the subject heat engine using different types of multiple sheets of laminate materials. FIGS. 2QA and 20B show the use of bent channels in the laminate material to prevent the pinching off of fluid flow when the cylinder arrays are folded in a serpentine engine design. FIG. 21 illustrates the use of a channel plug when joining together opposite ends of a flexible housing with cylinder arrays thereon. FIG. 22 shows one of the cylinder arrays of the heat engine having a plurality of regenerator tubes connecting the hot and cold exchanger sections for improved transfer of the inert gas used in the engine. FIGS. 23A, 23B and 23C illustrate the use of partially filled liquid bags as a concept in moving a liquid under pressure to be incorporated into a new Stirling heat engine design. FIG. 24 shows the use of cylinder arrays with the hot and cold exchanger sections using the partially filled liquid bag concept and regulated by inert gas pressure. FIG. 24A shows a sectional view of a high pressure value used for controlling fluid flow to a cylinder array shown in FIG. 24. FIG. 24B illustrates an end view of cold exchanger section taken along lines 24B-24B shown in FIG. 24. FIGS. 25 and 26 show the use of gas exchange bags for controlling the pressure to the cold exchanger sections of the new heat engine design using partially filled liquid bags.

FIGS. 27, 27A and 27B illustrate the use of insulators for protecting the hot and cold exchanger sections and connecting tube for heat and cold loss. FIG. 28 is a perspective view of a portion of the heat engine inside a pressurized vessel with insulators used to protect the cylinder arrays from heat and cold transfer and provide improved engine efficiency by filling dead air space inside the engine.

BEST MODE FOR CARRYING OUT THE INVENTION AND INDUSTRIAL APPLICABILITY Referring to FIG. 1 a front view of a prior art multi-cylinder fluidyne heat pump is illustrated and having a general reference numeral 10. The heat pump 10 includes a series of interconnected "U" shaped cylinders 12 having a liquid piston 14 therein. Disposed inside the cylinders 12 and above the right hand side of the liquid piston 14, is cold gas section 16 where a working gas such as helium is cooled. Likewise above the left hand side of the liquid piston 14, is a hot gas section 18 where the working gas is heated. The cold gas sections 16 and the hot gas sections 18 are connected through the use of regenerator tubes 20. The regenerator tubes 20 act to reduce the inefficiencies which are caused by heating and cooling the working gas in the cylinders 12. By alternately heating and cooling the working gas, the liquid pistons 14 oscillate back and forth in the cylinders 12. This application of a Stirling engine with liquid pistons is called a Siemens arrangement. In FIG. 2 a front view of the liquid piston heat engine of the present invention is shown having a general reference numeral 22. The heat engine 22 can also be used equally well as a heat pump for refrigeration units and other pump applications, for discussion herein, the subject invention will be referred to as a heat engine for producing mechanical rotary motion. When used as a heat engine, the engine 22 rotates about and is attached to a rotating axis 24. The engine 22 may include a single non-symmetrical cylinder, but in the embodiment shown a plurality of non- symmetrical cylinders 26 are used, with each non-symmetrical cylinder 26 having a cold exchanger section 30 and a hot exchanger section 28. Each of the adjacent cylinders 26 are connected with regenerator tubes 32 for providing greater efficiency when cooling and heating a working gas contained therein. In FIG. 2 the engine 22 is shown to include an array of cylinders having a general reference numeral 34. In this example the cylinder array 34 includes four interconnected non-symmetrical cylinders 26, although any array of two or more cylinders may be used. It should be noted that the array 34 is off-set from the axis 24 rather than being concentric therearound. In each of the cylinders 26 is a liquid such as water or any other appropriate liquid, with the remaining space in the cylinders filled with an inert gas 38 such as helium. In operation, the liquid acts as a liquid piston 36, and the gas 38 therein acts as a working gas wherein the gas 38 is alternately heated in the hot exchanger section 28 of each cylinder 26, where it is expanded and the gas is subsequently cooled in the cold exchanger section 30 where the gas 38 is caused to compress. The cooling and heating of the working gas 38 in each cylinder 26 causes the liquid piston 36 to oscillate back and forth from the hot exchanger section 28 to the cold exchanger section 30 and then back again. In FIG. 2 the gas 38 is shown without shading. This motion is sustained because the working gas, by oscillating the liquid pistons in the cylinders outwardly during a downward power

stroke and osculating the liquid pistons in the cylinders inwardly during an upward drag stroke cause the center of mass of the liquid of said pistons to be greater during the power stroke than during the drag stroke. In FIG. 3 the engine 22 is shown with both an upper and lower cylinder array 34. The arrays 34 are attached to the axis 24 and disposed are shown 180 degrees to each other. In this embodiment of the invention, the arrays 34 each include a pair of non-symmetrical cylinders 26 with hot exchanger sections 28 and cold exchanger sections 30. For working the gas 38 in the cylinders 36, an exterior cooling source and heating source is used, such as hot or cold waste water introduced through hot water sprays 40 and cold water sprays 42. When cold water is sprayed it acts to cool and compress the gas 38 in the portion of the cold exchange 30 with which it makes contact, while the hot water is which is sprayed acts to heat and expand the gas 38 in the portion of the heat exchange with which it makes contact. While liquid sprays 40 and 42 are shown in FIG.3, it can be appreciated that the cylinders 26 could be cooled and heated using water jackets therein, with hot or cold gases, or a variety of other ways. It should also be appreciated that what is now illustrated as a heat exchanger may be a cold exchanger, so long as a sequence of heating one end of liquid piston and cooling the other end is maintained. By using the Seimens arrangement with liquid piston as shown in FIG.1 and 2, no valving is required and the only moving parts are the gas 38, the liquid 36, and the rotating cylinder array 34 on the axis 24. It has been found that when there are multiple arrays 34 as shown in FIG. 8, that liquid piston control is required using valving, solenoids, acoustic speakers, and the like. In FIG. 4 an end view of the engine 22 as shown in FIG. 3 is illustrated. In this view, the engine 22 is rotating in a clockwise manner as indicated by arrow 46. Also shown is a vertical axis 48 for illustrating a 6:00 clock and a 12:00 clock position during rotation and a horizontal axis 50 for representing a 3:00 clock and 9:00 clock position. In FIG. 4 the upper cylinder array 34 is in a 1:30 clock position and the lower cylinder array 34 is in a 7:30 clock position. It is important to note that in these positions the majority of the liquid piston 28 in the liquid piston 36 in the upper cylinder array 34 has been purposely cycled into the hot exchanger section 28 so that the center of mass of the liquid shown as a dark shaded circle 47 is cycled outwardly during the downward power stroke of the engine 22. At the same time, the liquid in the liquid piston 30 in the lower cylinder array 34 as been cycled inwardly with the majority of the liquid 36 in the cold exchanger section 30, thereby having a center of mass which is shown as a dark shaded area 49. With the majority of the mass of the liquid in the lower cylinder array 34 thus being positioned as close as possible to the rotating axis 24, the moment of force of the array 34 during the upward drag stroke is reduced. FIG.3 also shows a flexible closed, balloon like diaphragms 41 attached to and in fluid contact with various portions of each cylinder 26. The use of diaphragms 41, which is optional, allows "open" systems to be pressurized and "closed" with and outer pressure enclosure flexible diaphragm 41. If entire system or entire engine is made from flexible plastic, each flexible diaphragm 41 can be of approximately equal size. This modification may also be beneficial in converting a "closed" system into acting like an pressurized "open" system at greater than one atmosphere in order to gain the efficiency of a pressurized system, as discussed below. Additionally,

the expansion space provided by flexible diaphragms 41 may be advantageous where different portions of the system are at different pressures. The mass distribution of the liquid piston 36 in the upper cylinder 34 is illustrated in FIG A through FIG.5H, and the mass distribution of the liquid piston 36 in the lower cylinder 34 is illustrated in the following FIG. 7A through FIG. 7H, all of which are discussed in greater detail below. In FIG. 5A the upper cylinder array 34 is shown in a 12:00 clock position with the center of mass 47 of the liquid piston 36 in a 4 position. The number 4 being a numerical value based on a range of positions 1 through 5, with 1 being the closest position to the axis 24 and the 5 position being the furthest position from the axis 24. In FIG. 5B the center of mass 47 of the liquid piston 36, as the cylinder array 34 starts its downward power stroke, moves to a 5 position or the furthest position from the axis 24. At this 1:30 clock position, the engine 22 has its greatest moment of force as it rotates about the axis 24. In FIG. 5C the upper cylinder array 34 has moved to a 3:00 clock position and the center of mass 47 has moved back to a 4 position. In FIG. 5D the array 34 is now at a 4:30 clock position and the center of mass is now at a 3 position. At the bottom of the power stroke of the engine 22 and at a 6:00 clock position the center of mass 47 of the liquid piston 36 is now at a 2 position as shown in FIG. 5E. In FIG. 5F the cylinder array 34 has started its rotation upwardly in a drag stroke mode, at a 7:30 clock position, with the center of mass 47 now at a 1 position closest to the axis 24. As the array 34 moves upwardly into a 9:00 clock position shown in FIG. 5G, the center of mass 47 moves to a 2 position. In FIG. 5G the array 34 is now in a 10:30 clock position with the center of mass 47 in a 3 position. The array 34 now completes the drag stroke as it returns to the 12:00 clock position as described with respect to FIG. 5A. This motion is sustained because the working gas, by oscillating the liquid pistons in the cylinders outwardly during a downward power stroke and oscillating the liquid pistons in the cylinders inwardly during an upward drag stroke cause the center of mass of the liquid of said pistons to be greater during the power stroke than during the drag stroke. In FIG. 6 a total cycle of the top cylinder array 34 is shown including each position of center of mass 47 as shown, which coincide with the various positions shown in FIG. 5A through FIG. 5H. By plotting the square unit area of the center of mass 47, in the eight different positions as described above, it is found that the unit area for the center of mass for the power stroke has value of, 22 shown as shaded area 52. Likewise the unit area for the center of mass for the drag stroke has a value of 8 and shown as unshaded area 54. The power stroke has been found to have an average moment arm of a value 3 while the drag stroke has an average moment arm of a value 2. Taking these moment of force arm values times their respective unit area for center of mass, we have a value of 16 for the drag stroke and a value for the power stroke of 66 and a total value of 82. By taking 66-16 over 82 it is shown that the. top cylinder array 34 has a total power potential of 61% of the liquid mass by properly cycling the liquid piston 36 during the power and drag stroke of the engine 22. In FIG. 6. the overall center of mass of the power stroke is shown as dot 51, with

the overall center of mass of the drag stroke is shown as dot 53. Thus the motion is sustained because the working gas, by oscillating the liquid pistons in the cylinders outwardly during a downward power stroke and oscillating the liquid pistons in the cylinders inwardly during an upward drag stroke cause the center of mass of the liquid of said pistons to be greater during the power stroke than during the drag stroke. In FIG. 7A through FIG. 7H eight positions of the lower cylinder array 34 are shown. FIG- 7A the lower cylinder array 34 is at the bottom of the power stroke of the engine 22 and at a 6:00 dod position. The center of mass 49 of the liquid piston 36 is at a 2 position. FIG. 7B shows the lower cylinder array 34 moving upward in a drag stroke mode at a 7:30 dodc position and the center of mass 49 at a 1 position. In FIG. 7C the array 34 has moved to a 9:00 dodc position and the center of mass 49 has now moved to a 2 position. As the array continues to move upwardly in the drag stroke mode to a 10:30 dock position, the center of mass 49 in the array 34 as shown in FIG.7D has moved to a 3 position. FIG. 7E shows the array 34 at the top of the drag stroke and now in a position to start downwardly into a power stroke. In this 12:00 clock position, the center of mass 49 is in a 4 position. In FIG. 7F the lower cylinder array 34 has started its power stroke and the center of mass 49 at a 1:30 position is at a 5 position. FIG. 7G shows the array 34 at a 3:00 dodc position and the center of mass at a 4 position. In the last of the eight positions, the array 34 in FIG 7H. has moved to a 4:30 position and the center of mass 49 is at a 3 position. While a total cyde of the bottom cylinder array 34 is not shown as it is in FIG. 6 with respect to the upper cylinder array 34, it has been found that plotting the center of mass 49 in the lower cylinder array 34 at the eight positions in the rotational cyde is substantially the same as the explanation of center of mass 47 in the upper cylinder array 34. Therefore by properly cycling the liquid piston 36 of the lower cylinder array 34, the total power potential is in the range of 60% or greater. This motion and power is sustained because the working gas, by osculating the liquid pistons in the cylinders outwardly during a downward power stroke and osdllating the liquid pistons in the cylinders inwardly during an upward drag stroke cause the center of mass of the liquid of said pistons to be greater during the power stroke than during the drag stroke. In FIG. 8 the heat engine 22 is shown in yet another embodiment with three cylinder arrays 34 equally spaced around the axis 24, with the arrays 120 degrees from one .another. As mentioned above the positioning of the liquid piston 36 in the arrays 34 may require sequencing using valves, acoustic speakers, solenoids, heaters and the like, when more than a single cylinder array 34 or an upper and lower array 34 are used. This is necessary to achieve proper oscillation and to achieve the goal of a greater power potential and to assure continuous rotation of the engine 22 and axis 24. FIG. 9 illustrates a cut-away perspective view of a portion of one of the cylinder arrays 34 having a flat plate construction for greater heat transfer. The array 34 in this example is made up of an upper flat plate 56 and a lower flat plate 58 with "U" shaped channels 62 formed therein for circulating the liquid piston 36 and gas 38 therein. The plates 56 and 58 may be made of various materials such, as copper sheet, aluminum, rubber, plastic, graphite composite, laminates and like

materials. The plates 56 and 58 may be secured together by heat sealing or by a securing agent 60, such as glue, solder, glass paste, and other types of adhesives, and bonding agents. The arrays 34 are formed into a desired shape as shown and filled with a working fluid such as water, water and anti- freeze, and may be inflated with a working gas such as helium, argon, nitrogen and other suitable gases. The advantages of an inflatable cylinder array 34 is that the material and manufacturing costs are low, the manufacturing process is simple, the resulting structure is light weight, and the heat engine 22 can be easily assembled and shaped to a final destination. For example the engine 22 can be fabricated, boxed and shipped from a factory and when delivered to a site, the cylinder arrays 34 filled at its site with the selected working fluid and than inflated with the working gas. In FIG. 10, yet another configuration of the unique heat engine 22 is shown wherein the length and size of the cylinder arrays is decreased from left to right. By decreasing the size of the arrays 34, the engine 22 is better able to control temperature differential between the cold exchanger sections 30 and the hot exchanger sections 28 of the different cylinder arrays 34 sustain rotation and produce power using the prindples and structures of the present invention. FIG. 11 illustrates the use of the heat engine 22 as shown in FIG. 3 for external heating or cooling. When the cold exchanger sections 30 passes through a portion of a walled partition 64 sections 28 of the cylinder arrays 34 are used for cooling of an area 65 surrounded by the partition 34, as shown by arrows 68. Likewise the hot exchanger sections 28 can pass through a portion of a walled partition 66 so that the sections 28 can be used for heating an external area 67 surrounded by the partition 66, or simply for the dissipation of the heat into the environment, as shown by arrows 69. FIG. 12 illustrates a sine wave 70 which is used to represent the oscillating frequency of the liquid piston 36 in one of the cylinder arrays 34. As mentioned under the discussion of FIG. 8, the sequencing of the liquid piston 36 can be accomplished using valves, acoustic speakers, solenoids, electric heaters, and the like. FIG. 12 illustrates such sequencing when an electric heater, not shown, is used inside or outside one of the arrays 34. In such an embodiment the only moving parts in the engine 22 would still be the oscillation of the liquid pistons 36 in the cylinder arrays 34 and the rotation of the engine 22 on the rotating axis 24. Such a heater could be electric, or activated by microwave or inductance which would eliminate the need to have to install electrical contacts inside the arrays 34. Referring again to FIG. 12, a horizontal dashed line 72 represents a bottom or 6:00 clock position of the liquid piston 36 while a horizontal dashed line 74 represents a top or 12:00 clock position of the piston 36. A vertical line 76 represents a velodty of the piston 36 as it oscillates in the cyhnder array 34. At point 78 on the sine wave 70, the heater is activated and the normal wave frequency is accelerated so that the modulation of the liquid column can be changed as the sine wave 70 moves from left to right. At point 80 on the sine wave 70, the electric heater is turned off and the liquid piston 36 now "coasts" into a desired position. By using the heater, the phase of the liquid pistons 36, oscillating in the cylinder arrays 34, can easily be changed so that proper synchronization is obtained for optimal performance of the heat engine 22. The use of fuzzy logic based calculations would be helpful in controlling such a sequence.

FIG. 13 illustrates the frequency phase of four different cylinder arrays 34. The first cylinder array 34 is shown as sine wave 82, while the second, third, and fourth arrays 34 are shown as sine waves 84, 86, and 88, respectively. The distance between vertical dashed lines 90 represent a full 360 degree cyde of the rotating heat engine 22. As represented in FIG. 13, the liquid piston 34 of the first array 34 is shown at a 12:00 dodc position when the top of the sine wave 82 crosses the dashed lines 90. At the same time the first array 34 is at a 12:00 dodc position, the liquid piston 36 of the second array 34 is shown at a 2:00 dodc position as represented by the sine wave 84. Likewise the liquid piston 34 of the third array 34 is shown by it's sine wave 86 at a 4:00 dock position, and the liquid piston 36 of the fourth array 34 is shown by it's sine wave 88 at the bottom of the frequency curve at a 6:00 dodc position when the first array 34 is at the 12:00 clock position. Once the liquid pistons 36 of the cylinder arrays 34 are optimized as to proper phase frequency, as shown in FIG. 13, the heat engine 22 should not require further input from the electric heater, while the engine 22 is running during normal operation. The heater would only be required during start-up. If one of the cylinder arrays has a liquid piston that is out of phase, for example with its gas pressure different than the pressure in the other cylinder arrays 34, then the electric heater could be used to correct the piston that is out of phase. With proper quality control during manufacturing of the engine 22 and careful control of the liquids and gases during the installation and start-up of the engine 22, the problem of unsynchronized phase frequency of the cylinder arrays 34 will be kept to a minimum. Also the frequency of the liquid pistons 36 can be monitored by a microprocessor. Any array 34 that is a continuous problem could be replaced. In FIG. 14, a configuration of the heat engine 22 is shown similar to that shown in FIG. 10, with the heat engine 22 endosed inside a pressurized vessel 110. The vessel 110 housing the cylinder arrays 34 therein. An interior 112 of the vessel 110 may be pressurized, for example, at 100 psi while an interior 114 of the hot and cold exchanger sections 28 and 30 are also pressurized, for example, at 90 psi. The pressure differential between the inside of exchanger sections 28 and 30 and the inside of the vessel 110 obviously being 10 psi. The pressurized vessel 110 housing the cylinder arrays 34 provides a design that allows the use of inexpensive materials for making up the hot and cold exchanger sections 28 and 30. Also, because the pressure difference from inside the exchanger sections 28 and 30 and the interior 112 is small, light weight and low strength material may also be used. For example, the near equal pressure on both sides of the exchanger sections 28 and 30 balances the pressure load and this in turn reduces the stress exerted on any seams in the exchanger sections. Further, the use of lighter weight materials provides for greater heat transfer and allows for reduced costs and weight. It should be pointed out that the embodiment shown in FIG. 14 allows for the pressure load of the overall system to be placed on the pressurized vessel 110. Since the vessel 110 carries the pressure load, the vessel can be strengthened to with stand extreme pressures, i. greater than 100 psi, without interfering with the performance of the cylinder arrays 34 as long as the pressure differential is kept at minimal. As a result, the pressurized design of the heat engine 22 as discussed above provides for a simplified design and light weight and low cost materials can be selected for reduced manufacturing costs.

The pressurizing of the heat engine 22 is of importance in that it has been found that Stirling engines operate more effiάently as internal pressure is increased within the engine. In the testing of prior art Stirling engine type designs, The Ford Motor Company found that an engine of this type can operate at over 50% effidency at internal pressures of 2800 psi. In FIG. 14A, a portion of the pressurized vessel 110 is shown with some of the cylinders 26 shown mounted to the rotating axis 24. Disposed between each of the cylinders 26 and inside the vessel 110 are heat pipes 102 and cold pipes 104 placed adjacent the hot exchanger sections 28 and cold exchanger sections 30 for providing improved heat and cold transfer to the engine 22. In FIG. 14B, the heat pipes 102 and cold pipes are alternated between the cylinders 26. In FIG. 14C, the vessel 110 is shown with alternating hot sections 106, shown with diagonal lines and cold sections 108 for improved heat and cold transfer and increasing the effidency of the engine 22. The hot exchanger section 106 can be made of a ceramic material while the cold exchanger section 108 can be made of steel or various other metal conductors. In FIG. 14D, the engine 22 with pressurized vessel 110 is shown with alternating hot exchanger sections 106 and cold exchanger sections 108. The vessel 110 is supplied with high pressure gas, such as helium, through a main supply line 105 to individual pressure lines 107, 109 and 111. The individual lines include pipe valves 113 under computer control for providing an alternating supply of gas to the hot and cold exchanger sections 106 and 108. The valves 113, and internal sensors not shown in the drawings will help control internal pressure inside the vessels 110 and inside the cylinders 26 so that any pressure variation is minimized and a proper pressure differential is maintained to protect the materials used in the construction of the heat engine 22. In FIG. 15, the basic liquid piston heat engine 22 is shown as illustrated in FIG. 2 but including both heat exchangers 116 and cold exchangers 118 incorporated into the structure of the hot exchanger section 28 and the cold exchanger section 30. The heat exchangers 116 are shown as a series of horizontal lines while the cold exchangers 118 are shown as a series of vertical lines. The heat and cold exchangers 116 and 118 are added to the heat engine 22 to increase the heat exchanger surface area which in turn improves the engine effidency and overall power out-put. The heat and cold exchangers 116 and 118 may be of various designs such as heating and cooling fins, metal heat sinks and the like. Also as mentioned in the above discussion under FIG. 2, the regenerator tubes 32 connecting the adjacent cylinders 26 provide for greater efficiency when cooling and heating a working gas contained in the heat engine 22. Heretofore, conventional Stirling engine designs have been limited in power output by the number of cylinders used in the engine. The Stirling heat engine 22, as described herein, is not inhibited by a limited number of cylinders and a great number of cylinders 26 can be linked together for greater power output. In FIG. 16A the subject heat engine 22 is shown with a plurality of cylincjer arrays 120 in a flexible housing 122 with fold lines 124. In this example each array 120 includes four cylinders 26. It can be appreciated that depending on the length of the engine 22 the arrays 120 can include any number of cylinders 26.

In FIG. 16B. the cylinder arrays 120 in the flexible housing 122 are shown in a serpentine engine design having a general reference numeral 126. The serpentine engine 126 is shown mounted on the rotating axis 24 with the arrays 120 extending along the length of the engine 126 and folded back in an endless manner back and forth and disposed 360 degrees around the axis 24. Opposite ends 128 and 130, shown in FIG. 16A, are connected in the serpentine design to form one endless and continuous serpentine cylinder array as shown in FIG. 16B. Each of the cylinder arrays 120 are synchronized so that the cylinder's liquid column osdllations are properly maintained for maximum engine effidency. Also, the cylinder arrays 120 are linked together for providing instantaneous feed-back and mechanical linkage is not required. Further, the serpentine engine 126 may have a hot and cold end configuration. The configuration will have heat transfer advantages such as cooling the cold end with evaporative water and/or heating the hot end with hot air, concentrated solar heat and the like. In FIG. 17A, one of the cylinders 26 of the heat engine 22 is shown having a working fluid 132 therein. As mentioned above, the fluid 132 can be water, a water and antifreeze mixture, a water soluble oil mixture and the like. In this figure, the cylinder 26 is shown with a pair of fluid drain tubes 134 mounted at opposite ends 136 and 138 of the cylinder 26. When the engine 22 is stopped, if the fluid level is too full in one of the cylinders 26, as shown in FIG. 17B, the fluid 132 will drain downwardly into the cylinder 26 below. When the heat engine 22 is started, a slow rotation about the axis 24 will equalize the fluid level in each of the cylinders 26. .After the fluid level is equalized, the heat engine 22 is than rotated faster and centrifugal force moves the working fluid 132 outwardly in each of the cylinders 26 as shown in FIG. 17C. As heat is introduced into the cylinders 26, the working fluid 132 acting as a liquid piston 36 is raised to a proper level in the engine 22 and the rotation about axis 24 is sustained as described under the description of FIG. 6. As shown in FIG. 18A, the fabrication of the heat engine 22 can be greatly simplified over conventional construction techniques by using a heat sealable first laminate sheet material 140 having a cylinder pattern 142 printed thereon using a water soluble ink. The cylinder pattern 142 may be printed using a screen printing method or any other printing technique commonly used on this type of material. After the ink on the cylinder pattern 142 is dried, a second laminate sheet material 144 is placed over the first laminate sheet material 140, as shown in FIG. 18B, and the two sheets are laminated together using a heat sealable laminating machine. The laminating machine is not shown in the drawings. When the laminating of the sheet materials 140 and 144 is completed, the water soluble ink used to make up the cylinder pattern 142 is flushed with water between the materials 140 and 144. The cavity that remains is now inflated and this void becomes the internal structure, such as the connecting tubes, heat and cold exchanger sections, regenerator, etc., making up the heat engine 22. The ink rinse water can be recyded for reuse after the excess water is evaporated or removed. The heat engine 22 can also be constructed of high strength materials using similar fabricating techniques as discussed under FIGS. 18A-18C. For example, an area 146, shown as diagonal lines in FIG. 19A, outside of the cylinder pattern 142 is coated with a high strength material such as epoxy on a high strength laminate first sheet material 148. The high strength

laminate sheet material 148 may be Kapton polymer, Kevlar graphite laminate material and the like. Referring now to FIG. 19B, the sheet material 148 is printed with the cylinder pattern 142 and the epoxy applied in the area 146. The epoxy and cylinder pattern 142 are dried under a heat lamp 150 with hot air circulated through the heat area shown between dotted lines 152. The first sheet material 148 is now combined with a second high strength laminate sheet material 154 which is rolled thereon. The combined first and second sheet materials 148 and 154 are now rolled around a mandrel 156 shown in FIG. 19C. The mandrel 156 is placed in a oven, shown as dotted lines 158, and the epoxy is allowed to cure at an elevated temperature and under pressure using a pressure boot 160. Multi-layer laminate structures of the heat engine 22 are possible using the above mentioned fabricating techniques. Also, the heat engine 22 may be constructed using conventional techniques such as electro-forming, investment casting and like methods. In addition to plastic, may be formed from any number of suitable materials, such as ceramic, aluminum, stainless steel, copper, and the like. In the use of flexible laminate sheet materials making up the flexible housing 122 with fold lines 124, various designs for bending the material will be required to prevent the pinching off the circulating working fluid 132 in the internal structure making up the heat engine 22. In FIG. 20A, the laminate material 140 includes the cylinder pattern 142 with a pluraϋty of vertical bend channels 162 which are interconnected and disposed between adjacent cylinders 26. The bend channels 162 allow the housing 122 to be folded in extreme angles as shown in the serpentine engine in FIG. 16B. FIG. 20B illustrates a top view of the laminate material 140 bent in 180 degrees using the bend channels 162 to prevent the pinching off of the working fluid 132 in any of the channels in the heat engine 22. When opposite ends 128 and 130 of the flexible housing 122 used in the heat engine 22 are joined together to form a continuous loop, the sealing of the two ends 128 and 130 will require that the working fluid channel is not obstructed. In FIG. 21, a non-heat sealable material or a channel plug 164 of water soluble ink is placed inside the open channels in the two ends 128 and 130. The ends 128 and 130 are then sandwiched between two sheets 166 of heat sealable material. The sheets 166 are shown in dotted lines. The sheets 166 are heated and the ends 128 and 130 are joined together and sealed with the plug 164 preventing the sealing of the two connected channels. In FIG. 22 the heat engine 22 is shown with the hot exchange section 28 and the cold exchange section 30 of the cylinders 26 having a plurality of gas transfer holes 168 with holes 168 in the cold exchange section 30 connected to the holes 168 in the hot exchange section 28 using a plurality of gas transfer regenerator tubes 170. The use of the gas transfer regenerator tubes 170 allows for increased transfer of the inert gas 38 between the hot exchange section 28 and the cold exchange section 30 rather than solely using the single regenerator tube 32 for oscillating the liquid piston 36. In FIG. 23A, the concept of using a partially filled liquid bag 174 is shown for use as a hot exchanger section 28, a cold exchanger section 20, as a liquid piston 38, a regenerator tube 32 and other applications related to the heat engine 22. By applying pressure as indicated by arrow 176 in

FIG. 23B, the liquid is pushed to a lower portion 178 of the bag 174. Likewise in FIG. 23C, pressure as indicated by arrows 180, is applied to the bag 174 and the liquid is pushed to an upper portion 182 of the bag 174. In FIG. 24, the concept of using a partially filled liquid bag is incorporated into a new type Stirling heat engine design having a general reference numeral 183. The heat engine 183 indudes the cold exchanger section 28 being a partially filled cold liquid bag 184 and the hot exchanger section 30 being a partially filled hot liquid bag 186. The two bags 184 and 186 are interconnected by connecting tube 188 with the liquid piston 36 therein. The bags 184 and 186 are partially filled with a liquid and than the inert gas 38 under pressure is received in the bags using a supply tube 190. The pressure in the bags, for example, may be in a range of lOOOpsi. The supply of pressure to the bags 184 and 186 is controlled using a valve control system 192. The control system is shown in FIG.24A taken along lines 24A-24A shown in FIG. 24. The valve control system 192 indudes a high pressure tube 194 received in a valve housing 196. When the pressure tube 194 is inflated as shown in FIG. 24A, the pressure tube 194 engages the side of a portion of a supply tube 190 and pinches off the flow of inert gas 38 which passes therethrough. The valve control system 192, can be used equally well to dose off different sections of the heat engine 183. Also, it can be appredated that other types of sealing systems similar to the system 192 could be used equally well in conjunction with the heat engine 22 and the liquid bag design engine 183. The pressure in the pressure tube 194, for example, can be in a range of 1010 psi, while the pressure of the inert gas inside the liquid bags is 1000 psi. Also, the pressure inside the pressurized vessel 110 may be slightly higher or lower than the 1000 psi inside the bags so that a small temperature differential is maintained inside the heat engine 183 so that different types of flexible material can be used in the construction of the heat engine as discussed under FTGS.18 and 19. Also mentioned above under the FIG. 14, the operation of the subject Stirling heat engines at high pressures allows for improved effidency in the operation. Also shown in FIG. 24 are inflatable gas exchanger bags 200 which are wrapped around each of the cold liquid bags 184 and hot liquid bags 186 for applying pressure on each bag and oscillating the liquid piston 38 and driving the heat engine 183. The bags 200 are shown in dotted lines in FIG. 24. FIG. 24B shows a side view of one of the bags 200 taken along lines 24B-24B shown in FIG. 24. In this view, the bag 200 surrounds a cold liquid bag 184. Under the control of valve control system 192, the bag 200 is supplied with high pressure gas through tubes 202. In one preferred embodimenζ bags 200 are subject to initial controlled gas pressurization, after which the valves are dosed, and thereafter there will be no control of the pressure in bags 200 by means of valve control system 192. Also the bags 200 may or may not be interconnected through tubes 32 depending on the desired application. In FIG. 25 a perspective view of a sectional portion of the new heat engine 183 is shown with a pair of gas exchange bags 200 disposed on opposite side of one of the cold liquid bags 184 which is similar- to a cold exchange section 30. The two bags 200 are connected to each other by one or more regenerator tubes 204. Also insulation 206 is placed between the two bags 200. The insulation 206 maybe a ceramic material, plastic, styrofoam, fiberglass and the like to retain the cold

and heat in each of the bags 200. Further, the two bags 200 may both be cold exchange bags, hot exchange bags, or a hot and cold exchange bag depending on the configuration of the cylinders of the heat engine 183. In FIG. 26 a perspective view of a sectional portion of the new heat engine 183 is shown incorporating the serpentine engine design shown in FIG. 16B. In this example, the cold liquid bag 184 of the engine 183 is shown making a 180 degree bend with a pair of side by side cold gas exchange bags 200 disposed between the bent bag 184. Also, the engine 183 indudes cold gas exchange bags 200 on the outside of the cold liquid bag 184. While the cold liquid bag 184 is shown with the cold gas exchange bags 200, it can be appredated that the liquid bag 184 acting as a hot exchange section 28 would operate in the same manner with the gas exchange bags 200. Also the Uquid bags 184 are shown protected with insulation 206 which not only acts to conserve heat and cold loss but also the insulation 206 acts to take up dead air space inside the pressurized vessel 110 for greater heat engine efficiency. In FIG. 27, one of the cylinders of the new heat engine 27 is shown similar to the embodiment shown in FIG. 24. In this figure the connecting tube 188 between the cold and hot liquid bags 184 and 186 is shown with a split external regenerator 208. The regenerator 208 is shown in dotted lines in this drawing. The regenerator 208 acts to maintain a proper heat and cold temperature control along the length of the connecting tube 188. .Also seen in FIG. 27 is semi- circular insulation 210, shown in dotted lines, disposed around a portion of the cold and hot liquid bags 184 and 186. FIG. 27A shows a cross section of the connecting tube 188 along lines 27A-27A shown in FIG. 27. In this view, the split external regenerator 208 can be seen surrounding the connecting tube 188. FIG. 27B shows a cross section of the cold liquid bag 184 and an end view of the semi-circular insulation 210. In FIG. 28, some of the cylinder arrays of the new heat engine 183 are shown received inside the pressurized vessel 110. The engine 183 is shown with the semi-circular insulation 210 disposed between two adjacent cold Uquid bags 184 and the insulation 210 between two adjacent hot Uquid bags 186. Also shown in this drawing is the use of an elongated piece of insulation 206 received next to one side of a cold Uquid bag 184 and a hot Uquid bag 186 for insulating the bags. Further, the use of the insulation 206 helps fill the dead .air space inside the vessel 110 thereby improving the efficiency of the heat engine 183. While the above discussed unique heat engine 22 has been discussed as an engine for rotating an axis and developing mechanical and electrical energy, it should be kept in mind that the cylinder arrays 34 as shown in FIGS. 2 and 3, could be used as stationary heat pumps. By this, the arrays 34, unlike the Siemans design shown in FIG. 1, have an increased surface area for improved heat transfer. Also a stationary heat engine, using the Stirling Uquid piston design, would have better heat transfer than conventional refrigerators using a Uquid/gas phase operation. StiU further the use of the StirUng Uquid piston with increase heat transfer properties, would not require the utilization of chlorofluorcarbons.

While the invention has been particularly shown, described and illustrated in detail with reference to preferred embodiments and modifications thereof, it should be understood by those skilled in the art that the foregoing and other modifications are exemplary only, and that equivalent changes in form and detail may be made therein without departing from the true spirit and scope of the invention as claimed, except as preduded by the prior art.