Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B71/00—Free-piston engines; Engines without rotary main shaft
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
  • F01B11/00—Reciprocating-piston machines or engines without rotary main shaft, e.g. of free-piston type
  • F01B11/02—Equalising or cushioning devices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
  • F01L21/00—Use of working pistons or pistons-rods as fluid-distributing valves or as valve-supporting elements, e.g. in free-piston machines
  • F01L21/04—Valves arranged in or on piston or piston-rod
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B63/00—Adaptations of engines for driving pumps, hand-held tools or electric generators; Portable combinations of engines with engine-driven devices
  • F02B63/04—Adaptations of engines for driving pumps, hand-held tools or electric generators; Portable combinations of engines with engine-driven devices for electric generators
  • F02B63/041—Linear electric generators
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
  • F01B7/00—Machines or engines with two or more pistons reciprocating within same cylinder or within essentially coaxial cylinders
  • F01B7/02—Machines or engines with two or more pistons reciprocating within same cylinder or within essentially coaxial cylinders with oppositely reciprocating pistons
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B75/00—Other engines
  • F02B75/28—Engines with two or more pistons reciprocating within same cylinder or within essentially coaxial cylinders

Definitions

• the present invention relates to an apparatus and a method for producing electric power.
• the present invention relates to an apparatus and a method for producing electric power intended for a stand-alone power generator or for being installed in transport means (including road vehicles, boats, aircrafts), working means, lifting means, in order to increase the charge duration of the batteries, or, more generally, intended for being associated as a supporting unit with any equipment where the need to increase the charge duration of the accumulators is felt, or yet for being used in plants for electric power production by means of renewable sources, in order to increase the accumulation capacity of the batteries.
• the present invention relates to an apparatus and a method for producing electric power from gas, i.e. methane, BioGAS, hydrogen or CNG such that the present invention also can be applied with fuels being obtained by regenerative processes.
• US Patent No. 6 349 683 discloses a two-stroke or four-stroke internal combustion engine including a cylinder in which a combustion chamber is formed and a piston arranged to reciprocate within the cylinder. To this end, the piston is connected to a rod, and a helical spring has one end fastened to the cylinder and the opposite end fastened to the rod associated with the piston, whereby the piston moves (in the expansion step) against the spring resistance.
• the rod at its distal end from the piston, carries an electrical induction coil that, by following the reciprocating motion of the piston, moves relative to a stationary permanent magnet, so as to generate electric power.
• US Patent Application No. 2002/0139323 discloses an internal combustion engine including a pair of opposed pistons which are rigidly connected together by means of a common rod and are driven in an oscillatory movement.
• Said common rod carries a coil that, by following the oscillatory motion of the rod, moves relative to a stationary permanent magnet, so as to generate electric power.
• the present invention provides an apparatus for producing electric power, including a housing at an end of which a substantially cylindrical portion is formed, wherein a piston is housed within said portion of said housing and delimits said combustion chamber, said piston being housed free within said portion of said housing and being arranged to reciprocate therein, said piston being connected to a end of a rod, the said rod has fastened thereto one or more support means carrying sets of movable magnetic means, facing sets of stationary magnetic means for producing electric power when the movable magnetic means are moved with respect to the stationary magnetic means,
• the piston comprises a piston valve being configured for blocking or unblocking an piston opening in the piston in order to provide air to the combustion chamber and/or in order to conduct exhaust gas from the combustion chamber.
• the apparatus for producing electric power can be configured for transforming chemical energy for example of a fuel into electrical energy using electrical and/or magnetic means.
• the apparatus more specifically can be understood as a
• the magnetic means can be a one or more permanent magnets or an induction coil, which is provided with electrical current if the magnet is activated.
• the present invention is based on the finding that an efficient operation of the apparatus can be realized, if air can be taken into the combustion chamber or if exhaust gas can be deducted out from the combustion chamber in a way with low resistance and a space-saving manner. This can be accomplished by providing the piston with a piston valve which blocks or unblocks an opening in the piston, such that a channel though the piston for air (to be taken into the combustion chamber) and/or for exhaust gas (to be conducted out of the combustion chamber) is controlled by the piston valve.
• air intake can then be accomplished in a state of the piston in which the piston is moving to enlarge the combustion chamber so as to put pressure on the air on the opposite of the piston (with respect to the combustion chamber) to pass though the opening in the piston (and an opened piston valve) into the combustion chamber.
• the combustion chamber can be filled with air in a very low resistant way.
• exhaust gas can conducted out of the combustion chamber though the opening in the piston (which is controlled by the piston valve), if for example the piston reduces the size of the combustion chamber by a respective movement. This also facilitates a deduction of exhaust gas with low resistance.
• due to the piston opening which is controllable by the piston valve, it is also possible to omit a separate duct for the intake of air to the combustion chamber or for deducing the exhaust gas from the combustion chamber.
• the present invention provides the advantage that by a little modification of known components of an apparatus for producing electrical power a significant improvement can be realized. Especially by reducing the resistance of the air intake or the deduction of exhaust gas it is now possible to fill the combustion chamber faster or to deduct the exhaust gas from the combustion chamber faster so that a higher efficiency of the apparatus for producing electrical power can be achieved. Furthermore, the apparatus disclosed here can be built in a space-saving manner as due to the piston opening in combination with the piston valve a duct on the outer surface of the housing can be omitted.
• the piston valve is configured for being actuated pneumatically and/or the piston valve being coupled with a spring in order to bring the piston valve into a position blocking the piston opening.
• the piston valve can therefore be reset by a spring to block the piston opening and/or to be opened by a pressure of fluid, being located opposite to the combustion chamber with respect to the piston.
• This embodiment of the present invention provides the advantage that the piston valve does not need an electrical contact or have an controllable means to be actuated which in turn would suffer a degradation while the lifetime of the apparatus due to the quick and strong movements of the piston carrying the piston valve.
• the piston valve can also be activated by an electronical means like a electronical magnet.
• another embodiment of the invention has a control chamber being fluidically coupled to the combustion chamber if the piston valve is opened.
• the combustion chamber can be understood as a chamber, which is located opposite the combustion chamber regarding the piston.
• the control chamber can be fluidically coupled with the combustion chamber if the piston valve is opened, such that a fluid like air or exhaust gases or fuel can pass from the control chamber though the piston opening to the combustion chamber or vice versa.
• Such an embodiment of the present invention provides the advantage of controlling the pressure in the control chamber such that for example the operation of the piston valve can in turn be indirectly controlled by the pressure in the control chamber. This facilitated the control of the piston valve due to the lack of active components being provided to the piston in order to open or close the piston valve.
• a control unit configured for controlling a pressure of a fluid in the control chamber.
• the control unit can be a unit which is capable to modify the pressure in the control chamber by controllable means, i.e. a valve, a heating element, an explosive pill etc....
• controllable means i.e. a valve, a heating element, an explosive pill etc.
• control unit is configured for controlling the pressure of the fluid in the control chamber by opening or closing a control valve, the control valve being arranged for blocking or unblocking a fluid passage form a fluid reservoir to the control chamber.
• This embodiment of the present invention provides the advantage of a technically very simple means in order to control the pressure of the fluid in the control chamber.
• the operation of the piston valve can be indirectly controlled in a very easy an effective way.
• control unit is configured for controlling the pressure in the control chamber by using an electrically activatable control means.
• control unit is configured for electrically actuating a magnet to open or close the control valve.
• the apparatus further comprises a housing valve being arranged in the housing of the apparatus, the housing valve being configured for blocking or unblocking an opening in the housing in order to provide air to the combustion chamber and/or in order to conduct exhaust gas from the combustion chamber, especially the housing valve being arranged in a wall segment of the housing opposite to the piston.
• a housing valve being arranged in the housing of the apparatus, the housing valve being configured for blocking or unblocking an opening in the housing in order to provide air to the combustion chamber and/or in order to conduct exhaust gas from the combustion chamber, especially the housing valve being arranged in a wall segment of the housing opposite to the piston.
• the movable magnetic means comprise at least one permanent magnet and/or the sets of stationary magnetic means comprise at least one induction coil.
• the apparatus comprises a second combustion chamber being formed at a second end of said housing at which a second substantially cylindrical portion is formed and wherein a second piston is housed within said second portion of said housing and delimits said second combustion chamber, said second piston being housed free within said second portion of said housing and being arranged to reciprocate therein, said second piston being connected to a first end of a second rod, the said second rod has fastened thereto one or more support means carrying second sets of movable magnetic means, facing second sets of stationary magnetic means for producing electric power when the second movable magnetic means are moved with respect to the second set of stationary magnetic means, characterized in that
• the second piston comprises a second piston valve being configured for blocking or unblocking a second piston opening in the second piston in order to provide air to the second combustion chamber and/or in order to conduct exhaust gas from the second combustion chamber.
• the apparatus comprises a third piston being connected at the rod at an opposed end to said piston and said second rod carrying a fourth piston at the opposed end to the second piston, said third piston and said fourth piston defining, together with the walls of said housing, a third combustion chamber formed in an intermediate portion of said housing, and wherein said third piston comprises a third piston valve being configured for blocking or unblocking a third piston opening in the third piston in order to provide air to the third combustion chamber and/or in order to conduct exhaust gas from the third combustion chamber and/or the fourth piston comprises a fourth piston valve being configured for blocking or unblocking a fourth piston opening in the fourth piston in order to provide air to the third combustion chamber and/or in order to conduct exhaust gas from the third combustion chamber.
• Such an embodiment of the present invention provides the advantage of a further increased efficiency of the present invention as already mentioned before, now not only in combination with two combustion chambers but also with three combustion chambers respectively pistons each being provided with said piston valve, wherein the three combustion chambers are coupled together with the rod and the second rod, each having two pistons as defined. This enables the operation of a very efficient apparatus for producing electrical power.
• said rod and said second rod are coaxially arranged, so that said third combustion chamber has a substantially cylindrical shape and/or wherein said rod and said second rod have the same size and mass, wherein said piston and second piston have the same size and mass and wherein said third and fourth pistons have the same size and mass.
• Controlling the piston valve such that air is provided to the combustion chamber and/or exhaust gas is conducted from the combustion chamber through the piston opening.
• control unit is also disclosed being configured for controlling and/or executing at least the step of the method disclosed in this description.
• the above mentioned advantages can also be realized by way of this control unit.
• a computer program for controlling and/or executing the step of the method as disclosed in this description, when the computer program is executed on a control unit.
• the apparatus for producing electric power can, for example, include a housing in which a first substantially cylindrical portion is formed, inside which a first combustion chamber is formed and a first piston is arranged to reciprocate. Moreover, a second substantially cylindrical portion is formed inside said housing, a second combustion chamber being formed inside the second portion and a second piston being arranged to reciprocate within the second portion.
• the first piston is connected to a first end of a first rod, which carries at its opposed second end a third piston.
• the second piston is connected to a first end of a second rod, which carries at its opposed second end a fourth piston.
• the third and fourth pistons define, together with the housing walls, a third combustion chamber, which is therefore located between said third and fourth pistons and within which said third and fourth pistons are arranged to reciprocate.
• the combustion chamber(s) the movable magnetic means and/or the the stationary magnetic means can have any displacement and/or can be water-cooled or air cooled.
• the first and second rods are coaxial, so that the third combustion chamber has a substantially cylindrical shape and the housing of the apparatus according to the invention has a substantially cylindrical shape.
• the first rod is for example rigidly connected, by means of one or more first supports, to a set of first coils / first permanent magnets that, by following the
• the second rod for example is rigidly connected, by means of one or more second supports, to a set of second coils / second permanent magnets that, by following the reciprocating motion of the second and fourth pistons, move relative to a set of stationary second permanent magnets / stationary second coils, so as to generate electric power.
• the movement of each piston is braked not only by the electric power generation but also by the compression of the piston located at the opposed end of the respective rod. Consequently, the embodiments described in this description allows overcoming the limitations of the prior art solutions, imposed by the provision of springs or other elastically resistant means.
• the approach described herein for example allows significantly reducing vibrations, since it comprises equal oscillating masses moving in opposition.
• the approach described herein for example allows reducing the displacement of the individual pistons, and consequently the overall size, for a given amount of electric power produced.
• the provision of said third combustion chamber, common to the third and fourth pistons allows synchronizing the system, i.e. the reciprocating movement of the first and second rods and of the elements connected thereto.
• the apparatus for producing electric power according to the invention can be manufactured by using standard, commercially available components, and this ensures reliability and limited prices.
• an apparatus for producing electric power including a housing at an end of which a portion is formed, wherein a piston is housed within said portion of said housing and delimits said combustion chamber, said piston being housed free within said portion of said housing and being arranged to reciprocate therein, said piston being connected to a end of a rod, the said rod has fastened thereto one or more support means carrying sets of movable magnetic means, facing sets of stationary magnetic means for producing electric power when the movable magnetic means are moved with respect to the stationary magnetic means
• an fuel injection means having a outlet to the combustion chamber, the outlet being arranged such that the outlet is fluidically disconnected to the combustion chamber in the state of the apparatus when fuel in the combustion chamber is exploded.
• This embodiment provides the advantage that the injection means can be effectively sheltered from high pressures which occur in the instance of the explosion of the fuel in the combustion chamber.
• he outlet of the fuel injection means is arranged such that it is covered by the piston in the state of the apparatus hen fuel in the combustion chamber is burnt.
• This embodiment of the invention provides the advantage that an easy positioning of the injection means can effectively shelter the components inside the injection means in the state the fuel explodes in the combustion chamber.
• the fuel injection means comprises a one way valve at an outlet nozzle, the one way valve being configured for fluidically coupling the fuel injection means with the combustion chamber for providing fuel into the combustion chamber and for fluidically disconnecting the fuel injection means from the combustion chamber in the state of the apparatus when fuel is burnt or exploded in the combustion chamber.
• the one way valve comprises a ball, being arranged to open said outlet nozzle for providing fuel into the combustion chamber and for closing said outlet nozzle in said state of the apparatus when fuel in the combustion chamber is burnt or exploded.
• the movable magnetic means comprise at least one permanent magnet and/or the set of stationary magnetic means comprise at least one induction coil. This arrangement rises the lifetime of the apparatus due to the lack of electrical connections to moving parts.
• a second combustion chamber is provided being formed at a second end of said housing at which a second substantially cylindrical portion is formed and wherein a second piston is housed within said second portion of said housing and delimits said second combustion chamber, said second piston being housed free within said second portion of said housing and being arranged to reciprocate therein, said second piston being connected to a end of a second rod, the said second rod has fastened thereto one or more support means carrying second sets of movable magnetic means, facing second sets of stationary magnetic means for producing electric power when the second movable magnetic means are moved with respect to the second set of stationary magnetic means,
• an second fuel injection means having a second outlet to the second combustion chamber, the second outlet being arranged such that the second outlet is fluidically disconnected to the second combustion chamber in the state of the apparatus when fuel in the second combustion chamber is burnt or exploded.
• a third piston is connected at the rod at an opposed end to said piston and said second rod carrying a fourth piston at the opposed end to the second piston, said third piston and said fourth piston defining, together with the walls of said housing, a third combustion chamber formed in an intermediate portion of said housing, and an third fuel injection means, having a third outlet to the third combustion chamber, the third outlet being arranged such that the third outlet is fluidically disconnected to the third combustion chamber in the state of the apparatus when fuel in the third combustion chamber is burnt or exploded.
• said rod and said second rod are coaxially arranged, so that said third combustion chamber has a
• a control unit is disclosed being configured for controlling and/or executing at least the step of the above mentioned method.
• an apparatus for producing electric power including a housing at an end of which a portion is formed, wherein a piston is housed within said portion of said housing and delimits said combustion chamber, said piston being housed free within said portion of said housing and being arranged to reciprocate therein, said piston being connected to a end of a rod, the said rod has fastened thereto one or more support means carrying sets of movable magnetic means, facing sets of stationary magnetic means for producing electric power when the movable magnetic means are moved with respect to the stationary magnetic means,
• an clutch unit for providing the stationary magnetic means or the movable magnetic means with electrical energy.
• This embodiment of the present invention provides the advantage to bring the rod in a defined position for example in the start up of the apparatus by implementing a defined magnetic force on the movable or stationary magnetic means which in turn brings the rod in the desired position.
• This can be done in order to facilitate the startup procedure of the apparatus as in this state the linear electromagnetic motor can be used for moving the pistons back and forth so as to regularize the movement of the pistons respectively the moveable magnetic means with respect to the stationary magnetic means.
• the clutch unit can be configured to stop providing electrical energy to the stationary or movable magnetic means and switch to a state in which electrical energy is collected from the linear motor respectively the moveable magnetic means with respect to the stationary magnetic means.
• the clutch unit is configured to provide induction coils of the stationary or movable magnetic means with a different current at different time intervals.
• the clutch unit is configured to provide the different coils of the stationary or movable magnetic means with a current at different time intervals, wherein the sum of the current is constant over a sum of several time intervals.
• the clutch unit can be configured to disconnect a provision of electrical energy to the moveable or stationary magnetic means and start a collection of electrical energy from the moveable or stationary magnetic means.
• This configuration of the clutch unit provides that advantage that the clutch unit facilitated the startup procedure of the apparatus, such that the normal operation mode of the apparatus can be reached in a shorter time after the startup of the apparatus.
• an apparatus for producing electric power including a housing at an end of which a portion is formed, wherein a piston is housed within said portion of said housing and delimits said combustion chamber , said piston being housed free within said portion of said housing and being arranged to reciprocate therein, said piston being connected to a end of a rod, the said rod has fastened thereto one or more support means carrying sets of movable magnetic means, facing sets of stationary magnetic means for producing electric power when the movable magnetic means are moved with respect to the stationary magnetic means,
• an exhaust pipe system for deducting exhaust gas from the combustion chamber and/or a second combustion chamber
• said exhaust pipe system has a first pipe and a second pipe, the first pipe element and the second pipe element each having a input for exhaust gas from the combustion chamber and/or a second combustion chamber, wherein the first pipe and the second pipe have a common output for said exhaust gas, wherein a length of the first pipe is longer than a length of the second pipe.
• Such an embodiment of the present invention provides the advantage that the noise originating from the combustion chambers can be extinguished by destructive overlap of the sound in the first and second pipes.
• the difference of the length of the first pipe and the length of the second pipe is dependent on at least one frequency in the spectrum of the noise of the exhaust gases and/or in that the difference of the first pipe and the length of the second pipe corresponds to a phase shift of 180 degrees at the common output at least one frequency of the spectrum of the noise of the exhaust gases.
• the difference of the length of the first and second pipe is in the range between 8.5m and 8.5mm, corresponding to a frequency range between 20 Hz and
• the second combustion chamber being formed at a second end of said housing at which a second substantially cylindrical portion is formed and wherein a second piston is housed within said second portion of said housing and delimits said second combustion chamber, said second piston being housed free within said second portion of said housing and being arranged to reciprocate therein, said second piston being connected to a (first) end of a second rod, the said second rod has fastened thereto one or more support means carrying second sets of movable magnetic means, facing second sets of stationary magnetic means for producing electric power when the second movable magnetic means are moved with respect to the second set of stationary magnetic means, characterized in that the first pipe is connected to the combustion chamber and the second pipe is connected to the second combustion chamber.
• a third piston being connected at the rod at an opposed end to said piston and said second rod carrying a fourth piston at the opposed end to the second piston, said third piston and said fourth piston defining, together with the walls of said housing, a third combustion chamber formed in an intermediate portion of said housing, and wherein said third piston comprises a third piston valve being configured for blocking or unblocking a third piston opening in the third piston in order to provide air to the third combustion chamber and/or in order to conduct exhaust gas from the third combustion chamber and/or the fourth piston comprises a fourth piston valve being configured for blocking or unblocking a fourth piston opening in the fourth piston in order to provide air to the third combustion chamber and/or in order to conduct exhaust gas from the third combustion chamber, characterized in that the exhaust pipe system has a third pipe being connected to the third combustion wherein the third pipe has a first portion and a second portion, the first and second portions being arranged in order to guide exhaust gas in parallel from a common third pipe inlet to a common third pipe junction, and the first
• an apparatus for producing electric power including a housing at an end of which a portion is formed, wherein a piston is housed within said portion of said housing and delimits said combustion chamber, said piston being housed free within said portion of said housing and being arranged to reciprocate therein, said piston being connected to a end of a rod, the said rod has fastened thereto one or more support means carrying sets of movable magnetic means, facing sets of stationary magnetic means for producing electric power when the movable magnetic means are moved with respect to the stationary magnetic means,
• the set of movable magnetic means are mounted on a flat ferromagnetic support means and by a further set of movable magnetic means, the further set of movable magnetic means being mounted on a further flat ferromagnetic support means at an opposite side of the rod with respect to the set of movable magnetic means.
• This embodiment of the present invention provides the advantage that a symmetric balance of the forces on the rod can be obtained such that the resulting torque can be minimized. Also it is possible to store a large about of kinetic energy in such an embodiment of the apparatus.
• each of the sets of movable magnetic means being arranged opposite of another of the set of movable magnetic means with respect to the rod.
• FIG. 1 a longitudinal sectional view of an apparatus for producing electric power in a first operating position, forming a basis for the explanation of specific embodiments of the present invention with respect to the figures 2 to 7;
• Fig. la schematically shows a longitudinal sectional view of the apparatus for producing electric power shown in Fig. la, in a second operating position;
• Fig. la schematically shows a longitudinal sectional view of the apparatus for producing electric power shown in Fig. la, in a third operating position;
• FIG. la schematically shows a longitudinal sectional view of the apparatus for producing electric power shown in Fig. la, in a fourth operating position;
• FIG. 2A and 2B show each cross-sectional views of the portion of the left hand side of the apparatus as depicted in the Figures la to ld having the piston;
• FIG. 3A shows a cross-sectional view of the ignition means for use in the apparatus as for example shown in Figure 2A or 2B;
• FIG. 4A and 4B each show a longitudinal sectional view of an embodiment of an apparatus for producing electric power
• FIG. 5 shows a longitudinal sectional view of another embodiment of an apparatus for producing electric power
• FIG. 6A schematically show each a longitudinal sectional view of another
• FIG. 6B shows a details section of the left side movable magnetic mean
• FIG. 6C shows a cross-sectional view of a detail of another embodiment of the moveable magnetic means
• FIG. 6D shows a cross-sectional view of a detail of another embodiment of the moveable magnetic means
• FIG. 6E shows a cross-sectional view of a detail of another embodiment of the moveable magnetic means
• FIG. 7 schematically shows a longitudinal sectional view of an embodiment of the apparatus for producing electric power
• FIG. 8 shows a flow chart of an embodiment of the present invention implemented as a method for operating an apparatus
• FIG. 9 shows a block diagram of an embodiment of the present invention
• Apparatus 1 includes a housing 3 at a (first) end of which a (first) substantially cylindrical portion 3 a is formed, housing a (first) combustion chamber 5 a.
• the (first) combustion chamber 5a has for example a substantially cylindrical shape and is equipped with fuel injection means (not shown in the Figures la to ld) and with ignition means 7a for fuel ignition.
• the (first) combustion chamber 5a is equipped with an inlet port 8a in communication with an inlet duct 9a for introducing air into the (first) combustion chamber.
• Said inlet duct 9a is in communication with an intake duct 1 la equipped with an intake valve lOa, and opens into the (first) combustion chamber or, preferably, into a pre-compression chamber connected thereto, as it will be described in detail hereinafter.
• the (first) combustion chamber 5a is also equipped with an outlet port l2a in communication with an exhaust duct 13a for the outflow of exhaust gases from the (first) combustion chamber.
• a (first) piston l5a is mounted free inside the (first) portion 3a of housing 3 and delimits the (first) combustion chamber 5a.
• the (first) piston l5a is housed in said (first) portion 3a of housing 3 so as to be able to reciprocate within it.
• housing 3 has a second (for example substantially cylindrical) portion 3b, housing a second combustion chamber 5b.
• the second combustion chamber 5b has a (for example substantially cylindrical) shape and is equipped with fuel injection means (not shown in the Figures la to ld) and with ignition means 7b for fuel ignition. Moreover, the second combustion chamber 5b is equipped with an inlet port 8b in communication with an inlet duct 9b for introducing air into the second combustion chamber. Said inlet duct 9b is in communication with an intake duct 1 lb equipped with an intake valve lOb, and opens into the second combustion chamber or, preferably, into a pre-compression chamber connected thereto, as it will be described in detail hereinafter. The second combustion chamber 5b is also equipped with an outlet port l2b in communication with an exhaust duct 13b for the outflow of exhaust gases from the second combustion chamber.
• a second piston l5b is mounted free inside the second portion 3b of housing 3 and delimits the second combustion chamber 5b.
• the second piston l5b is housed in said second portion 3b of housing 3 so as to be able to reciprocate within it.
• the (first) piston l5a is connected to a (first) end of a (first) rod l7a, which carries at its opposed end a third piston l5c
• the second piston l5b is connected to a (first) end of a second rod l7b, which carries at its opposed end a fourth piston l5d.
• the third piston l5c and the fourth piston 15d define, together with the walls of housing 3, a third combustion chamber 5 c, which is formed in an intermediate, substantially central portion 3 c of said housing 3.
• the third combustion chamber 5c is equipped with fuel injection means (not shown in the Figures la to ld) and with ignition means 7c for fuel ignition. Moreover, the third combustion chamber 5c is equipped with two inlet ports 8c, 8d in communication with respective inlet ducts 9c, 9d for introducing air into the third combustion chamber.
• a (first) inlet duct 9c is in communication with intake duct 1 la of the (first) combustion chamber 5 a through an intake valve lOc and opens into the second combustion chamber or, preferably, into a pre-compression chamber connected thereto, as it will be described in detail hereinafter.
• a second inlet duct 9d is in communication with intake duct 1 lb of the second combustion chamber 5b through an intake valve lOd and opens into the third combustion chamber or, preferably, into a pre-compression chamber connected thereto, as it will be described in detail hereinafter.
• the third combustion chamber 5 c is also equipped with two outlet ports l2c, l2d in communication with exhaust duct l3a of the (first) combustion chamber and exhaust duct 13b of the second combustion chamber, respectively, for the outflow of exhaust gases from the third combustion chamber.
• rods l7a, l7b are coaxially arranged, so that also the third combustion chamber 5 c has for example a substantially cylindrical shape and housing 3 of apparatus 1 has in the whole for example a substantially cylindrical shape.
• the (first) and second rods l7a, l7b have the same mass and the same size
• the (first) and second pistons l5a, l5b have the same mass and the same size
• the third and fourth pistons l5c, 15d have the same mass and the same size. More preferably, all pistons l5a - 15d have the same mass and the same size.
• the (first) rod l7a is mounted on longitudinal bearings l9a, l9c (or similar components) suitably arranged so as to define a (first) space 2la which is located between the (first) piston l5a and one of said bearings (bearing l9a) and is in communication with supply duct 1 la and inlet duct 9a of the (first) combustion chamber, and a second space 21 which is located between the (first) piston l5a and the other one l9c of said bearings and is in communication with supply duct 1 la and inlet duct 9c of the third combustion chamber.
• said spaces 2 la, 2lc can be advantageously exploited as pre-compression chambers for a first compression of air coming from supply duct 1 la before such air enters inlet duct 9a of the (first) combustion chamber or inlet duct 9c of the third combustion chamber, as it will be disclosed hereinafter.
• the second rod l7b is mounted on longitudinal bearings l9b, l9d (or similar components) suitably arranged so as to define a first space 2 lb which is located between the second piston l5b and one of said bearings (bearing l9b) and is in communication with supply duct 1 lb and inlet duct 9b of the second combustion chamber, and a second space 2ld which is located between the fourth piston 15d and the other one 19d of said bearings and is in communication with supply duct 1 lb and inlet duct 9d of the third combustion chamber.
• said spaces 2lb, 2ld can be advantageously exploited as pre-compression chambers for a (first) compression of air coming from supply duct 1 lb before such air enters inlet duct 9b of the second combustion chamber or inlet duct 9d of the third combustion chamber, as it will be disclosed hereinafter.
• one or more (first) supports 23 a are fastened to the (first) rod l7a, preferably in an intermediate position between the (first) piston l5a and the third piston l5c.
• Those supports carry sets of (first) magnets 25a facing sets of (first) induction coils 27a, so that, when the (first) piston l5a reciprocates within the (first) portion 3a of housing 3, the (first) magnets 25a reciprocate relative to the (first) coils 27a.
• two (first) supports 23a are fastened to the (first) rod l7a.
• Said supports are arranged at 180° relative to each other and each of them carries a respective set of (first) magnets 25 a, facing a respective set of (first) induction coils 27a.
• the (first) supports 23a could carry the induction coils and the magnets could be stationary and arranged so as to face the paths of said coils.
• one or more second supports 23b are fastened to the second rod l7b, preferably in an intermediate position between the second piston 15b and the fourth piston l5d.
• Those supports carry sets of second magnets 25b facing sets of second induction coils 27b, so that, when the second piston l5b reciprocates within the second portion 3b of housing 3, the second magnets 25b reciprocate relative to the second coils 27b.
• two second supports 23b are fastened to the second rod l7b.
• Said supports are arranged at 180° relative to each other and each of them carries a respective set of second magnets 25b, facing a respective set of second induction coils 27b.
• the second supports 23b are offset by 90° relative to the (first) supports
• the second supports 23b could carry the induction coils and the magnets could be stationary and arranged so as to face the path of said coils.
• apparatus 1 for producing electric power according to the invention comprises for example in the whole four sets of magnets (two sets of (first) magnets 25 a and two sets of second magnets 25b) and four sets of respective coils (two sets of (first) coils 27 a and two sets of second coils 27b) arranged in a cross- shaped pattern.
• Respective pumps for fuel injection and small pumps for lubricating oil can moreover be fastened to the (first) rod l7a as well as to the second rod l7b.
• supports 23a, 23b, as well as the elements associated therewith and further components, if any, mounted on rods l7a, l7b have the same mass and the same size, so as to maintain the overall symmetry of apparatus 1 for producing electric power.
• All pistons l5a to 15d operate according to the principle of a two-stroke engine.
• the third and fourth pistons l5c, 15d are at their minimum relative distance and compress the air- fuel mixture present in the third combustion chamber 5c.
• the (first) and second combustion chambers 5a, 5b are in communication with the respective inlet ducts 9a, 9b and exhaust ducts 13 a, l3b through the respective inlet ports 8a, 8b and outlet ports l2a, l2b.
• the air-fuel mixture present in the third combustion chamber 5c is therefore ignited and ignition occurs, as a consequence of which the third and fourth pistons l5c, l5d are moved away from each other.
• the (first) piston l5a moves towards the end of the (first) portion 3a of housing 3 and covers inlet port 8a and outlet port l2a.
• fuel is injected into the (first) combustion chamber and the (first) piston l5a starts compressing the air-fuel mixture present in said (first) combustion chamber 5a.
• the second piston l5b moves towards the end of the second portion 3b of housing 3 and covers inlet port 8b and outlet port l2b.
• fuel is injected into the second combustion chamber and the second piston 15b starts compressing the air- fuel mixture present in the second combustion chamber 5b.
• Fig. lc shows the step in which the distance between the (first) piston l5a and the end of the (first) portion 3 a of housing 3 is minimum, as is the distance between the second piston l5b and the end of the second portion 3b of housing 3.
• the third piston l5c and the fourth piston 15d start moving towards each other, so as to cover again inlet ports 8c, 8d and outlet ports l2c, l2d of the third combustion chamber 5c.
• fuel can be introduced into the third combustion chamber 5c and the third piston l5c and the fourth piston 15d, continuing their movement towards each other, compress the air- fuel mixture present in said third combustion chamber 5c. This step is shown in Fig. ld.
• the second piston 15b has moved away from the end of the second portion 3b of housing 3 sufficiently to uncover inlet port 8b and outlet port l2b, thereby allowing the outflow of exhaust gases into exhaust duct l3b and the substitution of said exhaust gases with pre-compressed fresh air coming from inlet duct 9b.
• the compressions in combustion chambers 5 a, 5 c located at the opposed sides of the (first) rod l7a determine, jointly with the production of electric power by the (first) magnets 25 a and the (first) coils 27a, the braking effect on said (first) rod l7a
• the compressions in combustion chambers 5b, 5c located at the opposed sides of the second rod l7b determine, jointly with the production of electric power by the second magnets 25b and the second coils 27b, the braking effect on said second rod l7b: it is the compressions in the combustion chambers located at the opposed sides of each rod that oppose the inertia of each rod, which is free.
• electric generation units consisting of the sets of magnets 25a, 25b and the sets of coils 27a, 27b can be advantageously exploited to start the cycle of compressions and expansions in the various combustion chambers 5a - 5c.
• coils 27a, 27b can be excited so as to bring the third and fourth pistons l5c, 15d to the position of maximum mutual distance, so as to allow filling the third combustion chamber 5c.
• the third and fourth pistons l5c, l5d can be moved towards each other so as to compress the air- fuel mixture present in said third combustion chamber. At this point, the mixture is ignited by ignition means 7c and the start takes place.
• the frequency of the reciprocating linear motion of rods l7a, l7b and of the pistons associated therewith can be adjusted so as to minimize fuel consumption.
• Said steady state condition should be constant, without accelerations or
• Apparatus 1 disclosed above may use, as fuel, any liquid or gaseous fuel available in the market (including gasoline, naphtha, kerosene, liquefied petroleum gas, methane and natural gas).
• any liquid or gaseous fuel available in the market including gasoline, naphtha, kerosene, liquefied petroleum gas, methane and natural gas.
• the apparatus advantageously comprises a reduced number of components.
• the previous description of the apparatus 1 should be modified because it refers mainly to applications with batteries, automotive in particular.
• applications as generators, micro cogenerators and generators for mini BioGAS power station can be also considered.
• the goal of the embodiments of this invention is to improve the generator by proposing the use of an intake valve on the top of the piston fueling fresh air into the combustion chamber. Additionally an optional exhaust valve on the top of the cylinder is also disclosed to evacuate the exhaust gases. This configuration allows a much better replacement of the exhaust with the intake during the scavenging phase and, at the same time, avoid the direct evacuation of intake gases - typical on simple conventional two stroke engines.
• By placing an injector directly into the combustion chamber according to another embodiment of the invention it is possible to improve the reliability of the injector itself because during the explosion it is protected by the piston again high pressures.
• a further improvement respectively embodiment of the invention is related to the exhaust system. By using matched pipes it is possible to reduce acoustic noise.
• the last improvement proposed according to an embodiment of the invention is the use of flat linear motors (having for example an iron core) in order to increase the magnetic force and the power generation. This kind of motors have much better performances but have the disadvantage of the strong attraction forces. To avoid this it is proposed to mount always two of them back-to-back in a symmetrical way around a rod so to cancel the effect of the attraction forces. Therefore the back-to-back positioning of the linear motors reduces the requirements of the bears.
• a first significant improvement can be obtained by a first embodiment of the present invention, if one of the ducts, specifically inlet duct 9a is modified such as to be integrated into the piston 15a for example.
• Figure 2A shows a cross-sectional view of the portion of the left hand side of the apparatus 1 as depicted in the Figures la to ld having the piston l5a.
• the embodiment of the present invention described hereafter can be implemented in a linear motor like the apparatus 1 but is not limited to the usage in such an apparatus.
• This embodiment can also be considered to be used in a conventional in-line engine or a flat engine.
• the skilled person thus understands, that the subsequent description of this embodiment of the present invention only is described as a modification of the exemplary apparatus 1 as shown in Figures 1 in order to describe the invention in details.
• the present invention is not limited to be used in an apparatus 1 as shown in Figures 1.
• the inlet duct (or a respective outlet duct 13 a) can be implemented into the piston l5a.
• the piston l5a can be provides with a piston opening 200a, which can be blocked (i.e. closed) or unblocked (i.e. opened) by a piston valve 205a.
• the piston valve 205a being can for example be reset by a spring 2l0a to a closed position, in which the piston opening 200a is blocked.
• This arrangement of the piston l5a with the piston opening 200a and the piston valve 205a now provides the advantage that the inlet duct 9a can be omitted, thus reducing the constructed space of the apparatus 1.
• a control chamber 215a is for example arranged below the piston l5a, i.e. which is at the opposite of the piston l5a with respect to the combustion chamber 5a.
• the control chamber 215a substitutes the pre-compression chamber 2 la.
• the control chamber 215a is fluidically sealed against the environment outside the housing 3 in order to include a fluid like air with a specific adjustable pressure.
• the pressure in the control unit 125 a can be adjusted for example by a control unit 220a, which in turn is capable to control an actuator 225a of a control valve 230a, for example by electrical means like an electrically magnet to open the control valve 230a; the closure of the control valve 230a can be performed by a control valve spring 240a.
• the control valve 230a is arranged to open or close a control chamber opening 235a, wherein in the open state of the control valve 230a air can be taken into the control chamber 215a by, for example, a compressor which is not shown in Figure 2A.
• the exhaust gas in the combustion chamber 5 a can be conducted outside the combustion chamber 5 a in order to prepare the combustion chamber 5 a for a new air intake though the piston opening 200a. Due to the preferred arrangement of the housing valve 250a opposite to the piston opening 200a in the piston l5a the intake and the outlet of the combustion chamber 5a are located as far away as possible and also in a direct line so that a constant flow of the air into the combustion chamber 5 a and an outlet of exhaust gas out of the combustion chamber 5 a can be implemented, such that a flow resistance of the fluid is minimized.
• Figure 2B shows a cross-sectional view of the combustion chamber 5a with the piston l5a and the control chamber 215a in a moment of the piston l5a in which fuel is ignited by the ignition means 7a.
• the outlet 260a of the injection means is covered by the piston l5a such that the explosion of fuel, which can be gas, gasoline, biogas (i.e. gas from renewable sources) or the like. If the outlet 260a of the injection means 245a is covered, stress on the output 245a can be significantly reduced such that the lifetime of the ignition means 245a can be prolonged in order to provide a better apparatus 1 for producing electric power.
• the intake which is marked in Figure 1A in a dark grey shadow in the lower part of the piston l5a is fed from the intake valve respectively the piston valve 205a placed in the piston l5a and pushes (in the direction of the big arrow shown in Figure 2A) the exhaust (which is marked in Figure 2 A with a light grey shadow) out through the exhaust valve (which is also named housing valve 250a) located on the opposite side of the cylinder wall with respect to the piston l5a. Therefore the uniformity of the air/gas flux is given by the central intake valve respectively the piston valve l5a.
• valves like the piston valve 205a or the control valve 230a
• the main aspect of the embodiment of the invention can be seen in the introduction of a said piston valve 205 a in the middle of the piston l5a which allows a very precise opening window thanks to the realization of this scavenging process is only possible by using valves.
• FIG 3 shows a cross-sectional view of the ignition means 245a for use in the apparatus 1 as for example shown in Figure 2 A or 2B.
• a one way valve 300 at the outlet 260a or nozzle 310 of the ignition means 245a is provided in order to avoid a high pressure, caused by the explosion of the fuel in the combustion chamber 5a, to enter the output 260a or nozzle 310 of the injection means 245 a.
• damage of components of the injection means 245a can mainly be reduced or avoided, which in turn again enlarges the lifetime of the apparatus 1.
• the one way valve 300 can comprise a ball 320, especially a metal ball, which covers a channel 330 for the fuel during the injection of the fuel into the combustion chamber 5a.
• the ball 320 is pressed on the opening of the channel 330 such that the interior components of the injection means 245a are protected when the explosion of the fuel occurs.
• a moving metallic ball 320 to protect the injector means 245a.
• Another solution is to use a metallic cylinder or of similar shape in metal to block the high temperature air coming into the injector means 245a.
• the efficiency of the engine or apparatus 1 is improved because of the increased gas compression. This is possible by exploiting the energy of the explosion itself during the up movement of the piston l5a. The result is a much more efficient and strong explosion.
• piston l5a having the piston valve 205a and the piston opening 200a
• this arrangement not necessarily must be implemented in combination with just one single combustion chamber 5 a as shown in the Figures 2A and 2B.
• the arrangement of the piston l5a with the piston valve 205a and the piston opening 200a can also be realized for the second combustion chamber 15b with the second piston 15b and the third combustion chamber 5c, having the third piston l5c and the fourth piston l5d.
• Figure 4A shows a longitudinal sectional view of an embodiment of an apparatus 1 for producing electric power in which the piston l5a, the second piston l5b, the third piston l5c as well as the fourth piston l5d are provided with respective piston openings 200a, 200b, 200c, 200d and corresponding piston valves 205a, 205b, 205c, 205d.
• the piston valves 205 and the piston openings 200 can be denoted with respect the
• a second control chamber 215b, a second control unit 220b, a second control valve 225b, a second ignition means 245b and a second housing valve 250b are provided in order to control the fluid, especially air, through the second piston opening 200b.
• a third control chamber 215c, a third control unit 220c, a third control valve 225c, a third injection means 245c and a third housing valve 250c are provided in order to control the fluid, especially air, through the third piston opening 200c.
• a fourth control chamber 2l5d, a fourth control unit 220d, a fourth control valve 225 d and a fourth injection means 245 d are provided in order to control the fluid, especially air, through the fourth piston opening 200d.
• Figure 4A shows a mechanical means 400a for opening and closing the housing valve 250a with respect to the movement of the rod l7a.
• a second mechanical means 400b is provided in order to open and close the second housing valve 250b with respect to the movement of the second rod l7b.
• a third mechanical means 400a for opening and closing the housing valve 250a with respect to the movement of the rod l7a.
• mechanical means 400c is provided in order to open and close the third housing valve 250c with respect to the movement of the rod l7a and the second rod l7b.
• FIG 4B schematically shows a longitudinal sectional view of another embodiment of an apparatus 1 for producing electric power.
• the control unit 220a is arranged to have a compressor (not shown) and a reservoir 4l0a in order to provide the desired pressure in the control chamber 215a.
• a part of the exhaust gas conducted out of the combustion chamber 5a by through the housing valve 250a is fed back to the inlet of the control chamber 215a, such that fluid or air to be taken into the control chamber 215a can be heated.
• the control unit 220a can be configured to (for example pneumatically or hydraulically) control also the housing valve 250a to open or to close in order to control the timing of the stated of the piston l5a in the operation of apparatus 1.
• the second piston l5b, the third piston l5c as well as the fourth piston l5d are also provided with the elements arranged as the previously described element with respect to the piston l5a, as shown in Figure 4B on the right hand side.
• the reference numerals are chosen accordingly to clarify the corresponding elements in the combination with the second piston l5b, the third piston l5c and the fourth piston l5d.
• valves 250a, 230a 205a and the corresponding valves with respect of the second piston l5b, the third piston l5c and the fourth piston l5d can be controlled mechanically (as can be seen from Figure 4A, with rods and levers as mechanical means 400) or electronically (as can be seen in Figure 4B, pneumatic and hydraulic).
• the electronic control can be preferred in order to be flexible in the opening and closing time.
• the exhaust valve or housing valve 250 being defined on the cylinder head respectively the piston 15, as an alternative one could place the valve for the air intake on the on the side near to the head respectively to the wall of the housing at a position, in which the housing valve 150 is located in the figures 2A and 2B for example.
• Possible alternative could also be the gas flow. It is suggestes to have the intake valve or piston valve 105 on the piston 15 and the exhaust valve or housing valve 250 on the cylinder head in the housing 3. As alternative the flow of fluid or gas could be defined flow from the head (then intake valve) to the valve in the piston 15 for the exhaust gas.
• valves in the wall of the housing are not necessary for the functionality of the embodiment described herein.
• the use of valves on the head of the cylinder is thus not the main focus, it would be also advantageous to have only the valve in the piston and not the combination of both valves.
• Figure 5 schematically shows a longitudinal sectional view of another embodiment of an apparatus 1 for producing electric power.
• the apparatus 1 as shown in Figure 5 is based on the embodiment of the pistons l5a to 15d having the piston openings 200a to 200d as well as the piston valves 205a to 205 d.
• an exhaust pipe system 500 is provided, having a first pipe 505 and a second pipe 510.
• the first pipe 505 is configured for conducting exhaust gas from the housing valve 250a to a junction 515 wherein the second pipe 510 is configured for conducting exhaust gas from the second housing valve 250b to the junction 515.
• the first pipe 505 has a first length Li and the second pipe 510 has a second length L 2 .
• the second length L 2 is by a length difference DR longer than the first length Li.
• This length difference DR is chosen such that noise originating from the combustion chamber 5 a extinguishes with noise, originating from the second combustion chamber 5b.
• the length difference DR can be chosen to be between 8.5m and 8.5mm.
• Frequency signai 20Hz and 20’000Hz can be extinguished, especially if the noise in the combustion chamber 5 a and the second combustion chamber 5b is generated at nearly the same time instant, which is true for the operation of the apparatus according Figure 5.
• the exhaust pipe system 500 shown in Figure 5 can also be implemented without the arrangement of the pistons l5a to 15d, having the piston openings 200a to 200d as well as the piston valves 205a to 205d.
• the exhaust gas system 500 can be applied to conventional in line motors or flat motors also, without loss of functionality, such that it has to be understood, that the description of the exhaust pipe system 500 (exhaust gas system) in the context with Figure 5 is only exemplary.
• a unique property of our free piston engine is the synchronization of the explosions. This guarantees the simultaneous explosion of the external combustion chambers followed by the simultaneous explosion of the internal ones.
• the exhaust pipes have been designed in a specific embodiment of the invention in such a way to cancel the acoustic noise at the output junction 515. This is realized by making the travel length Li in the first pipe 505 and the travel length L 2 in the second pipe 510 of the sound waves to have a phase shift of 180° at the pipes junction 515 for some well-defined frequency. At the pipes junction 515 the difference of the travel length of the sound waves has to be equal to DR according to Equ (1) such that the sound waves destructively overlap and a noise extinction occurs.
• Alternatives fo the pipes for the exhaust pipe system 500 could be in the shape of the exhaust pipe (round, rectangular, ). Here only the length used by the sound waves is specified, because physically it only depends on this fact.
• FIG. 6A schematically shows a longitudinal sectional view of another embodiment of an apparatus 1 for producing electric power.
• the movable magnetic means 25 a which are implemented as permanent magnets are mounted on a flat ferromagnetic support 23 a.
• This ferromagnetic support means 23 a is configured to have at opposite sides of the rod l7a two flat support members 600 on which the magnets 610 each are fixed.
• second rod l7b second movable magnetic means 25b are fixed, which are also implemented as permanent magnets and are mounted on a second flat ferromagnetic support 23b.
• This second ferromagnetic support means 23b is also configured to have at opposite sides of the rod l7a two flat support members 600 on which the magnets 610 each are fixed.
• the movable magnetic means are located paired around the rod l7a or l7b, which in turn provides the advantage that in a fast movement of the rod l7a or the second rod l7b the forces on the moveable magnetic means 23 a can be lowered due to a symmetrical arrangement around the rod l7a respectively the second rod l7b.
• the symmetrical arrangement of the flat support means provides the advantage to store a high amount of kinetic energy in the operation of the apparatus 1.
• Figure 6B shows a details section of the left side movable magnetic means 23a, in which the magnets 600 are positioned on the flat support means 600, which can be made of iron.
• the magnets 6110 are positioned such, that adjacent magnets 610 have different polarity at their faces 620
• Figure 6C shows a cross-sectional view of a detail of another embodiment of the moveable magnetic means 23 a, which can be applied in the apparatus 1 according to
• Figure 6D shows a cross-sectional view of a detail of another embodiment of the moveable magnetic means 23 a, which can be applied in the apparatus 1 according to
• FIG. 6A In contrast to the embodiment of Figure 6C now four flat support members 600 are provided, each being arranged opposite to another flat support means 600 around the rod l7a. This arrangement further improves the torque and the energy storage capacity of the moveable magnetic means 23a.
• Figure 6E shows a cross-sectional view of a detail of another embodiment of the moveable magnetic means 23a, which can be applied in the apparatus 1 according to Figure 6A.
• six flat support members 600 are provided, each being arranged opposite to another flat support means 600 around the rod l7a. This arrangement again further improves the torque and the energy storage capacity of the moveable magnetic means 25 a.
• FIG. 7 schematically shows a longitudinal sectional view of an embodiment of the apparatus 1 for producing electric power.
• at least one clutch unit 700 which is capable to provide the stationary magnetic means 27a or the second stationary magnetic means 27b with electrical energy.
• This clutch unit 700 is especially helpful in a startup situation of the apparatus 1, as this situation is one of the most critical issue of the free piston four combustion chambers engine, in particular the decoupling of the linear motors.
• the linear (electromagnetic) motors act as motor and control the movement of the pistons 15 to generate a synchronized movement allowing the explosions in all the four combustion engines.
• the startup process can only be successful if all four combustion chambers 5 have regular and synchronized explosions. But because during the startup step the power of the combustion motors can be much weaker than that of the linear motors -depends on the control algorithm- it is difficult to detect if the startup is successful or not and consequently it is very hard to find the right moment to switch off the linear motors.
• the pistons are for example controlled by a close loop algorithm of the linear motors where the position and velocity follow a well-defined setting.
• the magnetic clutch unit 700 works for example in such a way that as long as the forces of the combustion motors are lower than that of the linear motors, the pistons 15 follow the linear motors comprising the moveable and stationary magnetic means 23 and 27, but as soon the combustion motors start, the pistons 15 are free to follow the combustion motors.
• the realization of the magnetic clutch unit 700 is quite simple.
• the control algorithm is based on an open loop and set a constant current through the stator coils 710 of the linear motors. This current imposes a fix magnetic force, which can be calculated according to Equ. 2 moving the piston 15 and this is independent from its position.
• the magnetic force of the linear motor is always the same, i.e. is not increased as a function of the position or velocity, and therefore the piston 15 is free to move as soon as the force of the combustion motor is higher than that of the linear motor.
• the electronic circuits detect an acceleration of the piston 15, the current in the stator coils 710 is switched off and the movement is only given by the combustion motors.
• the linear motors are switched on again, but in this time as a current generators, thus converting the chemical energy of the combustion motors into electrical energy.
• the electrical energy is extracted from the linear motor by“misusing” the output stage of the inverter.
• the output transistors of the inverter are controlled as three independent step up converters.
• the piston movement charges the coil inductance
• the high side transistor are switched on (the low side transistors are off in this moment) the coil inductance discharges the accumulated energy on the DC-bus of the inverter.
• the operating mode of the linear motor during start up uses a magnetic clutch unit 700 because the final effect is the same. If the forces of the combustion chambers are high enough, then the clutch detach the linear motor from the pistons.
• This advantage can be implemented with an open loop control, i.e. the control logic is not monitoring and maintaining the position of the piston by changing the current value of the linear motor accordingly.
• Figure 8 shows a flow chart of an embodiment of the present invention implemented as a method 800 for operating an apparatus as disclosed herein.
• the method 800 comprises the step 810 of controlling the piston valve such that air is provided to the combustion chamber and/or exhaust gas is conducted from the combustion chamber through the piston opening.
• FIG. 9 shows a block diagram of an embodiment of the present invention implemented as a control unit 220 (220a to 220d) for operating an apparatus as disclosed herein.
• the control unit 220 respectively (220a to 220d) comprises a unit 910 for controlling the piston valve such that air is provided to the combustion chamber and/or exhaust gas is conducted from the combustion chamber through the piston opening.
• each rod carries two supports arranged at 180° relative to each other, it is also possible to provide rods carrying each a different number of supports: e.g., four supports arranged at 90° relative to one another could be associated with each rod.
• pistons operate according to the principle of a two-stroke engine
• pistons operate according to the principle of a four-stroke engine.

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• Combustion Methods Of Internal-Combustion Engines (AREA)

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• 2018
  • 2018-04-19 EP EP18723416.6A patent/EP3781788B1/de active Active
  • 2018-04-19 WO PCT/EP2018/060112 patent/WO2019201447A1/en active Application Filing

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