WO2011128773A1

WO2011128773A1 - Exhaust actuated free-piston kinetic engine

Info

Publication number: WO2011128773A1
Application number: PCT/IB2011/000873
Authority: WO
Inventors: Robert D. Hunt
Original assignee: Hunt Robert D
Priority date: 2010-04-13
Filing date: 2011-04-19
Publication date: 2011-10-20

Abstract

An exhaust actuated free-piston kinetic engine timed in response to alternating pressurized exhausts from at least two power cylinders having power pistons connected to power output rods within and having exhaust ports in the cylinder walls at the end of their strokes that alternately exhausts spent working fluid from the power cylinders that alternately applies force to the opposite sides of an actuator piston of a moveable valve actuator assembly as the power pistons alternately pass the exhaust ports in order to continuously drive or shuttle the assembly back and forth in a reciprocating manner to control the flow of pressurized working fluid into and out of the engine to run the engine and a suitable power take off means to produce power.

Description

EXHAUST ACTUATED FREE-PISTON KINETIC ENGINE

Background of the Invention

Free-piston kinetic engines have been the subject of intensive research during the past twenty- five years and many engine manufacturers tried to build commercial free piston engine models because of its attractive features, such as increased weight to power ratio and reduced frictional losses by the elimination of a heavy crank shaft with substantial vector angle losses. Extremely poor vector angles are produced during most of the rotation of a crankshaft. Over time all of them gave up primarily due to faulty actuation methodology after failing to develop suitable actuation means of timing and rimning the engine. There are many prior art patents that describe various means to actuate a free-piston engine such as slide valves used by old steam engines with problematic mechanical connections, poppet valves, reed valves, timing cams, electrically operated solenoid valves, and pressure actuation methods using a slave piston and cylinder designed to produce pressure differentials as the engine runs to drive an actuator assembly, and many other prior art attempts at actuation— all having substantial limitations.

Prior art kinetic engines of the electrically operated solenoid valve design are extremely problematic because they over heat with continuous use of over a few hundred cycles per minute as heat builds up in the resistance coils, they require a supply of electricity to operate, require an electronic control module, and need proximity sensors to operate. The sensors must be adjusted with even a slight pressure change— like the advance of an old distributor. And, as the inlet ports of solenoid valves become larger to allow additional flow, they operate substantially slower. Smaller inlet ports significantly restrict flow. Solenoid valves are very expensive to purchase and to maintain. Electrically operated solenoid valve experimental units have never been able to achieve high speed, high flow rate actuation as is needed to efficiently operate a free-piston engine.

Prior art free-piston kinetic engines of the pressure actuated design have a substantial number of severe problems, such as; the location at which actuation takes place varies with changes in pressure. Temperature changes and other factors can result in pressure changes as gases expand when heated and reduce in volume when cooled. In practice, it is very difficult to regulate the timing of these prior art pressure actuated engines. Cylinder pressure chamber leaks cause complete loss of pressure that can cause total failure to actuate which can then potentially cause the piston to slam into the end of the cylinder, possibly resulting in near complete destruction of the pressure actuation piston, cylinder and housing along with other equipment and catastrophic failure of the entire engine. Even when the engine does actuate, often it is not at the desired stroke length with the piston stoke being too short or too long. Another significant problem with prior art pressure actuation systems is that often the actuation is incomplete and the actuation pistons stop over the top of the working fluid ports stopping the flow of working fluid that results in locking the engine up under pressure, which potentially can be very dangerous. Use of compression cylinders with pistons disposed within them to produce the compressed gases that are used for pressure actuation increases the size of the engine, increases costs. Further, the large amount of energy required to operate these prior art pressure actuation units results in substantial parasitic power losses that substantially reduce the efficiency of the engine.

The present Inventor has filed International Patent Application Number PCT/IB2009/007766 titled, "Sprague Gear Transmission" dated December 16, 2009, which converts free-piston engine reciprocating linear motion to rotation in a single direction. The Sprague gear

transmission is a double-acting mechanism wherein a first Sprague gear catches (drives) during the forward direction of the reciprocating member and then a second Sprague gear catches (drives) during the backward direction of the reciprocating member and while the first Sprague gear catches (drives), the second Sprague gear slips (idles); and, while the second Sprague gear catches (drives), the first Sprague gear slips (idles). The driving outputs of both the first and second Sprague gears are mechanically coupled together by mating spur gears via parallel shaft means that continuously rotate in a single direction with at least one of the shafts providing power output rotation in a single direction.

Disclosure

An exhaust actuated free-piston kinetic engine is hereby disclosed that is timed in response to alternating pressurized exhausts from at least two power cylinders having power pistons connected to power output rods disposed within and having exhaust ports cut into the walls of the cylinders at the end of their strokes that alternately exhausts spent working fluid from the power cylinders. The two exhausts alternately apply force to the opposite sides of an actuator piston of a moveable valve actuator assembly as the power pistons alternately pass the exhaust ports in order to continuously drive or shuttle the actuator assembly back and forth in a reciprocating manner to control the flow of pressurized working fluid into and out of the engine to run the engine.

A synchronous belt and synchronous pulley system provide a suitable power take off means capable of coupling the power output rods together in order to coordinate their movement and to produce power. The belts drive a Sprague gear transmission capable of converting reciprocating linear motion into rotation in a single direction. The Sprague gear transmission is a double-acting mechanism wherein a first Sprague gear catches (drives) during the forward direction of the reciprocating member and then a second Sprague gear catches (drives) during the backward direction of the reciprocating member and while the first Sprague gear catches (drives), the second Sprague gear slips (idles); and, while the second Sprague gear catches (drives), the first Sprague gear slips (idles). The driving outputs of both the first and second Sprague gears are mechanically coupled together by mating spur gears via parallel shaft means that continuously rotate in a single direction with at least one of the shafts providing power output rotation in a single direction. The engine is capable of generating substantial power from kinetic energy sources such as pressurized gases and/or liquids, the hydrostatic pressure of a column of water, geopressure from wells including pressurized oil or natural gas wells, and pressure produced using thermal energy via conventional power cycles, including internal and external combustion, geothermal power, concentrated solar thermal power, waste heat and all other heat sources; and, the exhaust actuated free-piston kinetic engine may be used for any purpose or purposes for which any other engine may be used.

The free-piston kinetic engine is timed by its exhaust, being more fully described as more than one exhaust wherein as when a first exhaust takes place the timing is changed from a first position in response to an increase in pressure produced by the exhaust that causes movement of a set of shuttle pistons connected to a common shaft to a second position; and, wherein as the second exhaust takes place the timing is changed back to the first position in response to an increase in pressure produced by the exhaust that causes movement of the set of shuttle pistons in the opposite direction back to the first position in a cycle. The shuttling of the pistons back-and- forth alternately supplies pressurized working fluid to a set of pistons within a set of cylinders in order to produce mechanical power output.

The working fluid can be placed on the rod side of the pistons to produce tension instead of compression normally generated when the working fluid is placed on the side of the piston opposite the rod. Tension thereby is then used to pull a belt for a belt driven power take-off system. Tensile strength is much stronger than is compressive strength and there are many other advantages to the belt driven system such as operation life that is on the order to eight times as long as gear systems. Synchronous belts produce precise performance without the backlash created by gear systems. Two Sprague gears are pulled in a back-in-forth motion. Each gear is situated to drive in the opposite direction as the other gear in order to produce continuous rotary motion in one direction to provide smooth rotation.

Alternatively, the rods of each of the pistons are connected to rack bars that are connected together by a common set of spur gears so that the pistons move in opposite directions to each other. While the first piston is being powered by the force produced by the gaseous phase working fluid, the second adjacent piston within a cylinder produces compression of low pressure gaseous phase working fluid. Compression within the second piston aides to smoothly stop the forward motion of the piston during the final portion of its stroke and provides energy storage in the form of pressure that is available to turn around the direction of the piston and its connected rod upon actuation. The use of gears as cited above is not as beneficial as the use of belt driven power take-off systems.

Advantages of the exhaust actuated means of timing are:

(1) No electricity is required to start or operate the kinetic engine; and,

(2) Capable of attaining high speed, high flow rate precision actuation; and, (3) The site of actuation is exactly established by the position of the exhaust ports at the end of the desired piston stoke length; and,

(4) The full force of the working fluid is available for actuation; and,

(5) Full actuation takes place as the movement of the actuator cylinder must be sufficient to open the actuator exhaust ports in response to the pressure differential from the working fluid's higher pressure to the lower exhaust pressure; and,

(6) Elimination of compression pistons cylinders needed for prior art pressure actuation

means of timing, which means fewer moving parts are required; and,

(7) Increased power to weight ratio; and,

(8) Reduced frictional losses by the elimination of a heavy crank shaft with substantial vector angle losses; and,

(9) Lesser parasitic engine power losses due to the elimination of the slave pistons and

cylinders for prior art pressure actuation that consume substantial power.

The present patent produces kinetic engines having a smaller physical size with fewer expensive moving parts thereby reducing the cost of the units, decreasing the degree of parasitic losses, and increasing the efficiency of the engine over that of prior art kinetic engines.

The kinetic engine is capable of being operated with any pressurized fluid, including dual phase mixtures of gases and liquids, such as the hydrostatic pressure of a column of water, geopressure from wells including pressurized oil or natural gas wells and is capable of being driven by thermal power cycles, including internal and external combustion, geothermal power, concentrated solar thermal power, waste heat and all other heat sources.

Brief Description of the Drawings

Note: Drawing 1 through Drawing 6 all describe the Preferred Embodiment of the present invention and the numbers for each component remain uniform from one drawing to another for purposes of clarity, although the positions of the numbers are subject to change to reflect movement of these active parts of the engine.

Figure 1 describes the preferred embodiment of the exhaust actuated free-piston kinetic engine while in mid-stroke with the bottom power piston (180) driving. High pressure liquid and/or gas flows through the working fluid (136) inlet and flows through working fluid control throttle (170) into the actuator assembly housing (120) and flows through lower actuator fluid transfer port (176) into the bottom power cylinder (178) and applies force against the bottom power piston (180) that moves forward in response the substantial amount of force. The piston (180) is connected to the bottom power output rod (168) and it applies tension on the rod (168) that pulls it in the forward direction (to the left in the drawing) as well. The rod (168) penetrates a lower rod sealing gland (172) to the exterior of the engine where it is attached to a pliable synchronous belt (166) that is also pulled forward under tension. The belt (166) goes over idler roller (164) and around the lower portion of synchronous pulley (162) going past tension roller (146) to the top synchronous pulley (142) traveling around the upper portion of the pulley (142), thereby making a U-turn in the process that causes the belt (166) to reverse the direction of its pull from forward to backward (to the right on the drawing) for its upper portion. The belt (166) then goes under idler roller (140) and connects to the top power output rod (138) that is pulled backward by the movement of the belt (166). The rod (138) is connected to the top power output piston (132) that is also pulled backward by the belt (166).

The movement of the synchronous belt (166) causes rotation of both of the synchronous pulleys (142 & 162) in the clockwise direction as the teeth of the belt (166) mate with the teeth of the pulleys (142 & 162), which applies force to the pulleys (142 & 162). Each of the pulleys (142 & 162) have Sprague gears (144 & 160) attached to them that drive or catch when rotated in one direction only to transfer force and that idle or slip when rotated in the opposite direction. The bottom synchronous pulley (162) connected to the bottom Sprague gear (160) is engaged and is driving and the gear (160) rotates lower power shaft (158) that is coupled to spur gear (156) whose teeth mesh to transfer power to mating spur gear (148) to which the force transferred from the belt (166) to the pulley (162) to the Sprague gear (160) is transferred.

The top mating spur gear (148) is coupled to electrical generator (152) by the upper main power output shaft (150) that transfers the force from the shaft (150) to the generator (152) in order to provide a supply of electrical power (154). The top synchronous pulley (142) is connected to the top Sprague gear (144) that is connected by the main power output shaft (150) to mating spur gear (148). Both the shaft (150) and mating spur gear (148) rotate in the opposite direction as to the direction of rotation of the pulley (142) with the rotation of the pulley (142) being the wrong direction to produce power. However, Sprague gear (144) is not engaged and is idling or slipping in order to allow the pulley (142) to freely rotate in this wrong direction. The synchronous pulleys (142 & 162) change their direction of rotation with each stroke. However, the shafts (150 & 158) and mating spur gears (148 & 156) always rotate in the same direction, which (like a flywheel) allows them to conserve energy. Their inertia keeps them spinning without power input between power strokes that helps to smooth out the power output of the engine.

Lower power cylinder (178) has slots that form the bottom exhaust ports ( 182) near the end of its stroke and has a zone for high compression (186) beyond the ports (182) that are fluidly connected by the lower exhaust hose (104) and to the actuator assembly housing (120) just below the actuator piston (114). The sealed lower high compression zone (186) that becomes sealed after the power piston (180) passes the lower exhaust ports (182) is designed to slow and stop the stroke of the bottom piston (180) by the buildup of pressure to prevent it from striking the end of the cylinder (178). As lower piston (180) drives forward propelled by the pressurized working fluid (136), the piston (180) compresses gases (102 &186) on its opposite side due to decreasing volume. These pressurized gases (102 & 186) flow through port (182) and through the exhaust hose (104) and apply pressure to the underside of the actuator piston (114). The upper power piston ( 132) in the upper power cylinder (188) is pulled backward (to the right on the drawing) by the tension applied to the piston (132) by the forward motion of lower power piston (180), which results in expansion of the gases (100 & 106) on its opposite left side and. results in lowered pressure on the left side of piston (132) due to the increasing volume because the area is sealed by one way check valve (124) and by the internal gland (no number) within the center of the actuator housing (120) that prevents fluids from coming into the upper portion of actuator housing where the actuator piston (114) is located. The backward movement of upper power piston (132) sweeps any remaining fluids left over from the piston's (132) previous power stroke from the upper power cylinder (188) through upper actuator fluid transfer port (128) that flows through the interior of actuator housing (120) to the exhaust lines (184) in order to discharge these spent working fluids (122) from the engine.

In Drawing 1 all of the actuator pistons (114, 134, &174) are in their lower position. After actuation that will be more fully described in Drawing 3 and 6 that is caused by the alternating flow of pressurized exhaust through exhaust ports (130 & 182) that flows to the actuator piston (114), high pressure working fluid (136) applies force against the actuator piston (114) in order to change the position of the pistons (114, 134 & 174) from this lower position to their upper position then back again in response to the alternating exhaust pressures applied against the actuator piston (114). The positions switch from lower to upper to lower to upper in an alternating cycle that continuously shuttles the pistons (114, 134 & 174) back and forth to operate the engine by controlling the flow of working fluid into and out of the engine. In the current lower position flow control piston (134) allows working fluid (136) to discharge from upper power cylinder (188) and blocks the flow of fluid (136) into cylinder (188). In the upper position it will allow working fluid (136) to enter cylinder (188) and will block the discharge of fluid (136) from upper power cylinder (188). In the current lower position flow control piston (174) allows working fluid (136) to enter cylinder (178) and blocks the flow of working fluid (136) from discharging from lower power cylinder (178). In the upper position it will reverse and will allow working fluid (136) to discharge from lower power cylinder (178) and will block the inlet supply of fluid (136) into cylinder (178).

Lowered pressure on the left side of piston (132) due to the increasing volume as the power piston (132) moves backward is fluidly connected to the upper side of the actuator piston (114) via the upper power cylinder (188) that also has slots cut into the walls of the cylinder (188) that form the top exhaust ports (130) near the end of its stroke that are connected by the upper exhaust hose (108) to the actuator assembly housing (120) just above the actuator piston (114), which results in decreased pressure on the upper side of the actuator piston (114) as the pressure lowers.

The result of increased pressure on the bottom side of the actuator piston (114) and decreased pressure on its top side is that a potentially detrimental upward force is applied against the actuator piston (114) by this pressure differential. It is desirable for the actuator piston (114) to maintain its position though out the entire length of the power stroke. In order to regulate the pressure differential on each side of the actuator piston (114), pressure equalization line (110) fluidly connects the upper exhaust hose (108) and lower exhaust hose (104) with pressure regulator (112) inline to control the pressure differential to prevent a substantial force from occurring against the actuator piston (114) that would otherwise cause premature actuation of the actuator piston (114).

An external adjustable linear brake mechanism (118) is mounted to the top of actuator housing (120) having a movable plate capable of producing friction attached to the top of the common actuator rod (126) as a secondary means of preventing actuation before the end of the stroke of the power pistons (178 & 188) and as a means to limit the length of movement of the actuator piston (114). The linear brake (118) applies friction for stopping and holding the actuator piston (114) in place in the same manner as disc brakes that apply pressure against a rotary disc with brake pads to create friction to stop. The linear brake (118) dampens the back and forth momentum of the movable actuator assembly comprising; the actuator piston (114), the common rod (126) and the upper actuator flow control piston (134) and lower actuator flow control piston (174) and the reciprocating brake plate of the linear brake (118). The movable actuator assembly is housed within the actuator housing (120) that has an internal bore for the pistons (114, 134, & 174). The rod (126) penetrates the housing (120) through a gland (no number) and attaches to the linear brake mechanism (118).

Figure 2 describes the preferred embodiment of the exhaust actuated free-piston kinetic engine with pressured exhaust (136) from the bottom power cylinder (178) applying upward force to the actuator piston (114) just prior to actuation. High pressure liquid and/or gas flows through the working fluid (136) inlet and flows through working fluid control throttle (170) into the actuator assembly housing (120) and flows through lower actuator fluid transfer port (176) into the bottom power cylinder (178).

Forward movement of the bottom power piston (180) within the cylinder (178) has advanced until it has passed the exhaust port (182), which allows a flow of high pressure working fluid (136) to flow through port (182), through the lower exhaust hose (104) into the actuator housing (120) to beneath the actuator piston (114). And the pressurized working fluid (136) is applying substantial upward force against the actuator piston (114) that will very soon actuate (Shown in greater detail in Drawing 3 herein) by moving upward from its current lower position to its upward position in response to this large amount of force.

The bottom power piston (180) is still moving forward and is connected to the bottom power output rod (168) and it applies tension on the rod (168) that pulls it in the forward direction (to the left in the drawing) as well. The rod (168) penetrates a lower rod sealing gland (172) to the exterior of the engine where it is attached to a pliable synchronous belt (166) that is also pulled forward under tension. The belt (166) goes over idler roller (164) and around the lower portion of synchronous pulley (162) going past tension roller (146) to the top synchronous pulley (142) traveling around the upper portion of the pulley (142), thereby making a U-turn in the process that causes the belt (166) to reverse the direction of its pull from forward to backward (to the right on the drawing) for its upper portion. The belt (166) then goes under idler roller (140) and connects to the top power output rod (138) that is pulled backward by the movement of the belt (166). The rod (138) is connected to the top power output piston (132) that is also pulled backward by the belt (166).

The top mating spur gear (148) is coupled to electrical generator (152) by the upper main power output shaft (150) that transfers the force from the shaft (150) to the generator (152) in order to provide a supply of electrical power (154). The top synchronous pulley (142) is connected to the top Sprague gear (144) that is connected by the main power output shaft (150) to mating spur gear (148). Both the shaft (150) and mating spur gear (148) rotate in the opposite direction as to the direction of rotation of the pulley (142) with the rotation of the pulley (142) being the wrong direction to produce power. However, Sprague gear (144) is not engaged and is idling or slipping in order to allow the pulley (142) to freely rotate in this wrong direction.

The upper power piston (132) in the upper power cylinder (188) is still being pulled backward (to the right on the drawing) by the tension applied to the piston (132) by the forward motion of lower power piston (180), which results in expansion of the gases (100 & 106) on its opposite left side and results in lowered pressure on the left side of piston (132) due to the increasing volume because the area is sealed by one way check valve (124) and by the internal gland (no number) within the center of the actuator housing (120) that prevents fluids from coming into the upper portion of actuator housing where the actuator piston (114) is located. The backward movement of upper power piston (132) sweeps any remaining fluids left over from the piston's (132) previous power stroke from the upper power cylinder (188) through upper actuator fluid transfer port (128) that flow through the interior of actuator housing (120) to the exhaust lines (184) in order to discharge these spent working fluids (122) from the engine.

Lowered pressure on the left side of piston (132) due to the increasing volume as the power piston (132) moves backward is fluidly connected to the upper side of the actuator piston (114) via the upper power cylinder (188) that also has slots cut into the walls of the cylinder (188) that form the top exhaust ports (130) that are connected by the upper exhaust hose (108) to the actuator assembly housing (120) just above the actuator piston (114), which results in decreased pressure on the upper side of the actuator piston (114) as the pressure lowers; and, very high pressure resulting from exhaust of high pressure working fluid (136) from lower power cylinder (178) applies a very great upward force against the actuator piston (114) being a very large pressure differential being applied against the actuator piston (114) that will cause it to actuate to its upward position immediately.

Figure 3 describes the preferred embodiment of the exhaust actuated free-piston kinetic engine as the movable actuator assembly moves to its upward position during actuation. Upward pressure applied against the actuator piston (114) by the high pressure working fluid (136) caused it to move from its lower position to its current upper position.

Movement of the actuator piston (114) caused an equal movement to the common rod (126) connected to the upper actuator flow control piston (134), the lower actuator flow control piston (174) and the reciprocating brake plate of the linear brake (118) housed within the actuator housing (120) with the movement being stopped by linear brake mechanism (118). In its current upward position, working fluid (136) is allowed to enter upper power cylinder (188) and the discharge of fluid (136) from upper power cylinder (188) is blocked. Working fluid (136) is allowed to discharge from lower power cylinder (178) and the supply flow of working fluid (136) into cylinder (178) is blocked.

The current position is the end of the lower power piston's (180) stroke and its position is halted by the high pressure within the compression zone (186) produced during the piston's (180) forward movement into the sealed zone (186) that caused the pressure to build to a high level. The energy expended in compression is conserved like the recoil of a spring that has been compressed and it will be recovered in helping to reverse the direction of the lower power piston (180) and lower power output rod (168).

Spent working fluid (122) flows from the lower power cylinder (178) through the lower exhaust port (182) through exhaust hose (104) into the actuator housing (120), through the actuator exhaust port (116) and through the check valve (124) into the exhaust lines (184) and the spent working fluid (122) is discharged from the engine. Spent working fluid (122) also is allowed to flow from the lower power cylinder (178) through the opening at the bottom of actuator housing (120) to the exhaust lines (184) and that flow of spent working fluid (122) is also discharged from the engine.

These two discharges of spent working fluid (122) from the lower power cylinder (178) quickly drop the pressure in the cylinder (178) on the rod side of the piston (180), which allows the stored energy within the high pressure sealed compression zone (186) to reverse the direction of the lower power piston (180) and lower power output rod (168), recovering the conserved energy stored during the stroke. High pressure liquid and/or gas flows through the working fluid (136) inlet and flows through working fluid control throttle (170) into the actuator assembly housing (120) and flows through upper actuator fluid transfer port (128) into the top power cylinder (188) and applies force against the top power piston (132), which halts its backward movement, reverses the direction of the top power piston's (132) movement to the forward direction (to the left in the drawing) in response the substantial amount of force provided by the incoming pressurized working fluid (136). The change of direction is also aided by the low pressure within the sealed chamber on the opposite site of the piston (132) caused by its previous backward motion.

Figure 4 describes the preferred embodiment of the exhaust actuated free-piston kinetic engine while in mid-stroke with the top power piston (132) driving. High pressure liquid and/or gas flows through the working fluid (136) inlet and flows through working fluid control throttle (170) into the actuator assembly housing (120) and flows through upper actuator fluid transfer port (128) into the top power cylinder (188) and applies force against the top power piston (132) that moves forward in response the substantial amount of force. The piston (132) is connected to the top power output rod (138) and it applies tension on the rod (138) that pulls it in the forward direction (to the left in the drawing) as well. The rod (198) penetrates a sealing gland (no number) to the exterior of the engine where it is attached to a pliable synchronous belt (166) that is also pulled forward under tension.

The belt (166) goes under top idler roller (140) and around the upper portion of the upper synchronous pulley (142) going past tension roller (146) to the bottom synchronous pulley (162) traveling around the lower portion of the bottom pulley (162), thereby making a U-turn in the process that causes the belt (166) to reverse the direction of its pull from forward to backward (to the right on the drawing) for its lower portion. The belt (166) then goes under lower idler roller (164) and connects to the bottom power output rod (168) that is pulled backward by the movement of the belt (166). The lower rod (168) is connected to the lower power output piston (180) that is also pulled backward by the belt (166).

The movement of the synchronous belt (166) causes rotation of both of the synchronous pulleys (142 & 162) in the counter-clockwise direction as the teeth of the belt (166) mate with the teeth of the pulleys (142 & 162), which applies force to the pulleys (142 & 162). Each of the pulleys (142 & 162) have Sprague gears (144 & 160) attached to them that drive or catch when rotated in one direction only to transfer force and that idle or slip when rotated in the opposite direction. The top synchronous pulley (142) connected to the top Sprague gear (144) is engaged and is driving and the gear (144) rotates upper power shaft (150) that is coupled to upper spur gear (148) that is coupled to electrical generator (152) by the upper main power output shaft (150) that transfers the force from the shaft (150) to the generator (152) in order to provide a supply of electrical power (154). The lower mating spur gear's (156) teeth mesh with the upper mating spur gear (148) that causes rotation of the lower mating gear (156) and of the connected lower shaft (158) coupled to the gear (156) that is coupled to the lower Sprague gear (160) is not engaged and is idling or slipping in order to allow the lower pulley (162) to freely rotate.

Upper power cylinder (188) has slots that form the top exhaust ports (130) near the end of its stroke and has a zone for high compression (100) beyond the ports (130) that are fluidly connected by the upper exhaust hose (108) and to the actuator assembly housing (120) just above the actuator piston (114). The sealed upper high compression zone (100) that becomes sealed after the upper power piston (132) passes the upper exhaust ports (130) is designed to slow and stop the stroke of the top piston (132) by the buildup of pressure to prevent it from striking the end of the upper cylinder (188). As the upper piston (132) drives forward propelled by the pressurized working fluid (136), the piston (132) compresses gases (100 &106) on its opposite side due to decreasing volume. These pressurized gases (100 & 106) flow through exhaust port (130) and through the exhaust hose (108) and apply pressure to the top side of the actuator piston (114).

The lower power piston (180) in the lower power cylinder (178) is pulled backward (to the right on the drawing) by the tension applied to the piston (180) by the forward motion of upper power piston (132), which results in expansion of the gases (102 & 186) on its opposite left side and results in lowered pressure on the left side of piston (180) due to the increasing volume because the area is sealed by one way check valve (124) and by the internal gland (no number) within the center of the actuator housing (120) that prevents fluids from coming into the upper portion of actuator housing where the actuator piston (114) is located. The backward movement of lower power piston (180) sweeps any remaining spent fluids (122) left over from the piston's (180) previous power stroke in the lower power cylinder (178) through the opening at the bottom of the actuator housing (120) into the exhaust lines (184) in order to discharge these spent working fluids (122) from the engine.

Lowered pressure on the left side of piston (132) due to the increasing volume as the lower power piston (180) moves backward is fluidly connected to the lower side of the actuator piston (114) via the lower power cylinder (178) that also has slots cut into the walls of the cylinder (178) that form the bottom exhaust ports (182) that are connected by the lower exhaust hose (104) to the actuator assembly housing (120) just below the actuator piston (114), which results in decreased pressure on the lower side of the actuator piston (114) as the pressure lowers.

The result of increased pressure on the top side of the actuator piston (114) and decreased pressure on its bottom side is that a potentially detrimental downward force is applied against the actuator piston (114) by this pressure differential that is prevented by the friction brake mechanism (118) and the pressure release line (110) with an inline pressure regulator (112). Figure 5 describes the preferred embodiment of the exhaust actuated free-piston kinetic engine with pressured exhaust (136) from the top power cylinder (188) applying downward force to the actuator piston (114) just prior to actuation. High pressure liquid and/or gas flows through the working fluid (136) inlet and flows through working fluid control throttle (170) into the actuator assembly housing (120) and flows through upper actuator fluid transfer port (128) into the top power cylinder (178).

Forward movement of the top power piston (132) within the top cylinder (188) has advanced until it has passed the top exhaust port (130), which allows a flow of high pressure working fluid (136) to flow through port (130), through the upper exhaust hose (108) into the actuator housing (120) to just above the actuator piston (114). And the pressurized working fluid (136) is applying substantial downward force against the actuator piston (114) that will very soon actuate (Shown in greater detail in Drawing 6 herein) by moving downward from its current upper position to its lower position in response to this large amount of force.

The top power piston (132) is still moving forward and is connected to the top power output rod (138) and it applies tension on the rod (138) that pulls it in the forward direction (to the left in the drawing) as well. The rod (138) penetrates an upper rod sealing gland (no number) to the exterior of the engine where it is attached to a pliable synchronous belt (166) that is also pulled forward under tension.

The movement of the synchronous belt (166) causes rotation of both of the synchronous pulleys (142 & 162) in the counter-clockwise direction as the teeth of the belt (166) mate with the teeth of the pulleys (142 & 162), which applies force to the pulleys (142 & 162). The top synchronous pulley (142) connected to the top Sprague gear (144) is engaged and is driving and the top mating gear (144) rotates upper power shaft (150) that is coupled to upper spur gear (148) that is coupled to electrical generator (152) by the upper main power output shaft (150) that transfers the force from the shaft (150) to the generator (152) in order to provide a supply of electrical power (154).

The lower mating spur gear's (156) teeth mesh with the upper mating spur gear (148) that causes rotation of the lower mating gear (156) and of the connected lower shaft (158) coupled to the gear (156) that is coupled to the lower Sprague gear (160) is not engaged and is idling or slipping in order to allow the lower pulley (162) to freely rotate.

Lowered pressure on the left side of the lower power piston (132) due to the increasing volume as the power piston (132) moves backward being fluidly connected to the lower side of the actuator piston (114) via the lower power cylinder (178) that also has slots cut into the walls of the cylinder (178) that form the bottom exhaust ports (182) that are connected by the lower exhaust hose (104) to the actuator assembly housing (120) just below the actuator piston (114), which results in decreased pressure on the lower side of the actuator piston (114) as the pressure lowers; and, very high pressure resulting from exhaust of high pressure working fluid (136) from lower power cylinder (178) applies a very great upward force against the actuator piston (114) being a very large pressure differential being applied against the actuator piston (114) that will cause it to actuate upward immediately to its upward position.

Figure 6 describes the preferred embodiment of the exhaust actuated free-piston kinetic engine as the movable actuator assembly moves back its original downward position during actuation in a continuous cycle. Downward pressure applied against the actuator piston (114) by the high pressure working fluid (136) caused it to move from its upper position to its current original lower position.

The downward movement of the actuator piston (114) caused an equal downward movement of the common rod (126) connected to the upper actuator flow control piston (134), the lower actuator flow control piston (174) and the reciprocating brake plate of the linear brake (118) housed within the actuator housing (120) with the movement being stopped by linear brake mechanism (118). In its current downward position, working fluid (136) is allowed to enter lower power cylinder (178) and the discharge of fluid (136) from lower power cylinder (178) is blocked. Working fluid (136) is allowed to discharge from upper power cylinder (188) and the supply flow of working fluid (136) into cylinder (188) is blocked.

The current position is the end of the upper power piston's (180) stroke and its position is halted by the high pressure within the compression zone (100) produced during the piston's (132) forward movement into the sealed zone (100) that caused the pressure to build to a high level. The energy expended in compression is conserved like the recoil of a spring that has been compressed and it will be recovered in helping to reverse the direction of the upper power piston (132) and the upper power output rod (138).

Spent working fluid (122) flows from the upper power cylinder (188) through the upper exhaust port (130) through exhaust hose (108) into the actuator housing (120), through the actuator exhaust port (116) and through the check valve (124) into the exhaust lines (184) and the spent working fluid (122) is discharged from the engine. Spent working fluid (122) also is allowed to flow from the upper power cylinder (188) through upper fluid transport port (128) and up through the actuator housing (120) to the exhaust lines (184) and that flow of spent working fluid (122) is also discharged from the engine.

These two discharges of spent working fluid (122) from the upper power cylinder (188) quickly drop the pressure in the cylinder (188) on the upper rod (138) side of the upper power piston (132), which allows the stored energy within the high pressure sealed compression zone (100) to reverse the direction of the upper power piston (132) and upper power output rod (138), recovering the conserved energy stored during the stroke.

High pressure liquid and/or gas flows through the working fluid (136) inlet and flows through working fluid control throttle (170) into the actuator assembly housing (120) and flows through the lower actuator fluid transfer port (176) into the lower power cylinder (178) and applies force against the lower power piston (180), which halts its backward movement, reverses the direction of the lower power piston's (180) movement to the forward direction (to the left in the drawing) in response the substantial amount of force provided by the incoming pressurized working fluid (136). The change of direction is also aided by the low pressure within the sealed chamber on the opposite site of the piston (180) caused by its previous backward motion that resulted in expansion of the gases and lowered pressure within the chamber. The current original conditions complete the actuation cycle; being (a) the beginning downward position of the actuator piston (114) with the bottom power piston (180) driving to; (b) the upward force being applied against the actuator piston (114) by the pressurized working fluid (136) exhaust from the bottom power cylinder (178) to; (c) actuation of the actuator piston (114) to the upward position as a result the upward force of the pressurized working fluid (136) exhaust from the bottom power cylinder (178) being applied to the actuator piston (114) at the end as the original stroke to; (d) the top power piston (132) driving as a result of the actuator piston (114) being in its upward position after actuation to; (e) downward force being applied against the actuator piston (114) by the pressurized working fluid (136) exhaust from the top power cylinder (188) to; (f) actuation of the actuator piston (114) back to its original downward position as a result the downward force of the pressurized working fluid (136) exhaust from the top power cylinder (188) being applied to the actuator piston (114) at the end top power piston's (132) stroke to; (a) that completes the cycle and again returns to the original conditions of beginning that are repeated in a continuous cycle to operate the free-piston kinetic engine of the present invention.

Claims

Claims:

(1) An exhaust actuated free-piston kinetic engine is hereby claimed capable of being timed in response to alternating pressures produced by the exhausts of at least two cylinders that continuously drive a valve actuator assembly back and forth that controls the flows of pressurized working fluid into and out of the engine in order to run the engine comprising; a suitable framework and housing, a suitable throttle to control the flow rate of working fluid into the engine, at least two power cylinders having exhaust ports cut into the walls of the cylinders at or near the end of their strokes and having power pistons connected to power output rods disposed within the power cylinders that alternately exhausts spent working fluid from the power cylinders as the pistons alternately pass the exhaust ports, a suitable power take off means capable of coupling at least two power output rods together to coordinate movement of the rods and in order to produce power, an actuator assembly having an actuator piston capable of being continuously driven or shuttled back and forth by the alternating pressures produced by the alternating exhausts from the two exhaust ports of the cylinders, at least two hoses or lines running from the two cylinder exhaust ports to each side of the actuator piston alternately applying force to the opposite sides of the actuator piston in order to drive or shuttle the assembly back and forth in a reciprocating manner to control the flow of pressurized working fluid into and out of the engine in order to operate the exhaust actuated free-piston kinetic engine being capable of generating substantial power from kinetic energy sources such as pressurized gases and/or liquids, the hydrostatic pressure of a column of water, geopressure from wells including pressurized oil or natural gas wells, and pressure produced using thermal energy via conventional power cycles, including internal and external combustion, geothermal power, concentrated solar thermal power, waste heat and all other heat sources; and, the exhaust actuated free-piston kinetic engine may be used for any purpose or purposes for which any other engine may be used.

(2) The exhaust actuated free-piston kinetic engine of claim 1 wherein the movable actuator assembly comprises at least one actuator piston coupled by a common rod to at least two pistons capable of controlling the flow of working fluid into and out of the two power cylinders of the engine in response to exhaust pressures alternately applied to opposite sides of the actuator piston that causes the assembly to continuously shuttle back and forth, with the pistons and rod being disposed within at least one actuator cylinder having suitable inlet and outlet ports cut into the walls of the cylinder that houses the moveable actuator assembly.

(3) The exhaust actuated free-piston kinetic engine of claim 1 wherein the power output rods are connected to a linear alternator power take-off means capable of transferring the linear back and forth motion of the engine into electrical power in a very efficient manner.

(4) The exhaust actuated free-piston kinetic engine of claim 1 wherein the power output rods are under tension via the inlet flow of working fluid being on the rod side of the power piston and are connected to the pliable belt of a synchronous belt and synchronous pulley system power take-off means capable of transferring the linear reciprocating force produced by the engine to a Sprague gear transmission that converts the linear back-and- forth motion into rotary motion in a single direction being useful for the production of electrical power or to provide rotational motive forces to drive wheels, propellers, or for any other purpose for which rotation is used.

(5) The exhaust actuated free-piston kinetic engine of claim 1 wherein the power output rods are connected to a rigid rack bar and pinion gear power take-off means capable of transferring the linear back and forth force motion either under tension or compression to a Sprague gear transmission that converts the linear back-and-forth motion into rotary motion in a single direction being useful for the production of electrical power or to provide rotational motive forces to drive wheels, propellers, or for any other purpose for which rotation is used.

(6) The exhaust actuated free-piston kinetic engine of claim 1 wherein the power output rods are connected to hydraulic rams as a power take-off means either under tension or compression in order to convert the linear back and forth motion of the engine into mechanical pressurization and pumping of liquid fluids such as water or hydraulic fluids being useful as a water pump in dewatering oil and gas wells or as a high pressure hydraulic pump capable of powering heavy equipment such as bulldozers and excavators.

(7) The exhaust actuated free-piston kinetic engine of claim 1 wherein the power output rods are connected to pneumatic rams as a power take-off means either under tension or compression in order to convert the linear back and forth motion of the engine into mechanical compression of gases useful for compression of low pressure natural gas into the gas transmission lines in the natural gas industry among many other uses.

(8) The exhaust actuated free-piston kinetic engine of claim 1 wherein the engine is powered by low temperature external combustion selected from such species as natural gas or other low carbon emission fossil fuel sources in order to reduce the amount of pollutants produced by the engine performing the elimination of the production of nitrous oxide that is formed during high temperature and high pressure combustion due to the low temperature nature of the combustion, along with low carbon emission due to the fuel source. (9) The exhaust actuated free-piston kinetic engine of claim 1 wherein a linear friction brake mechanism capable of preventing premature actuation of the engine and capable of cushioning the throw of the moveable actuator assembly comprising; a rigid flat metal plate or disc or ceramic plate or disc that is connected to the reciprocating actuator rod of the actuator assembly, stationary brake pads that are compressed against the disc or plate to generate friction in order to produce slowing, stopping and braking of the movement of the actuator assembly as the result of friction between the flat plate or disc and the brake pads.