DE4024591A1 - FREE PISTON ENGINE - Google Patents

FREE PISTON ENGINE

Info

Publication number
DE4024591A1
DE4024591A1 DE19904024591 DE4024591A DE4024591A1 DE 4024591 A1 DE4024591 A1 DE 4024591A1 DE 19904024591 DE19904024591 DE 19904024591 DE 4024591 A DE4024591 A DE 4024591A DE 4024591 A1 DE4024591 A1 DE 4024591A1
Authority
DE
Germany
Prior art keywords
piston
pistons
free
piston engine
engine according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
DE19904024591
Other languages
German (de)
Inventor
Gerhard Brandl
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to DE19904024591 priority Critical patent/DE4024591A1/en
Priority to PCT/EP1991/001460 priority patent/WO1992002730A1/en
Publication of DE4024591A1 publication Critical patent/DE4024591A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B7/00—Piston machines or pumps characterised by having positively-driven valving
    • F04B7/0003—Piston machines or pumps characterised by having positively-driven valving the distribution member forming both the inlet and discharge distributor for one single pumping chamber
    • F04B7/0015—Piston machines or pumps characterised by having positively-driven valving the distribution member forming both the inlet and discharge distributor for one single pumping chamber and having a slidable movement
    • 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
    • F02B71/04—Adaptations of such engines for special use; Combinations of such engines with apparatus driven thereby
    • F02B71/045—Adaptations of such engines for special use; Combinations of such engines with apparatus driven thereby with hydrostatic transmission
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B17/00—Pumps characterised by combination with, or adaptation to, specific driving engines or motors
    • F04B17/05—Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by internal-combustion engines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B19/00—Machines or pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B1/00 - F04B17/00
    • F04B19/003—Machines or pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B1/00 - F04B17/00 free-piston type pumps

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)
  • Valve Device For Special Equipments (AREA)

Abstract

A free-piston engine has one or more pistons (1) which are preferably rigidly connected to hydraulic pistons (2) and which move freely in cylinders along the longitudinal axis. The rear face of the piston (1) is used to convey the combustion air and the piston movement is induced and controlled by electronically actuated hydraulic valves (8).

Description

Der Freikolbenmotor hat einen oder mehrere Kolben (1), mit denen Ölkolben (2) starr verbunden sind, siehe Bild 1, oder zwei gegeneinander arbeitende Kolben (1), siehe Bild 2. Die Hinterseite der Kolben (1) wird zur Förderung der Verbrennungsluft über Einlaßschlitz (4), Überströmkanal (5) und Auslaßschlitz (6) verwendet.The free-piston engine has one or more pistons ( 1 ) with which oil pistons ( 2 ) are rigidly connected, see Figure 1, or two pistons ( 1 ) working against each other, see Figure 2. The rear of the pistons ( 1 ) is used to convey the combustion air via inlet slot ( 4 ), overflow channel ( 5 ) and outlet slot ( 6 ) used.

Die Kolben (1) werden durch entsprechende Betätigung der Hydraulikventile (8) in eine hin- und herschwingende Bewegung versetzt. In den Hydraulikventilen (8) sind Ventilschieber (9), die durch elektrisch betätigte Vorsteuerventile (10) angeregt eine schwingende Bewegung ausführen. Aus der Schwingbewegung der Ventilschieber (9) ergibt sich die Schwingung der Kolben (1). Ein Mikroprozessor (12) schaltet die Vorsteuerventile (10) und sorgt damit für die Ingangsetzung und Stabilisierung der Schwingung der Kolben (1).The pistons ( 1 ) are set in a reciprocating motion by corresponding actuation of the hydraulic valves ( 8 ). In the hydraulic valves ( 8 ) there are valve spools ( 9 ) which, when actuated by electrically operated pilot valves ( 10 ), execute an oscillating movement. The oscillation of the pistons ( 1 ) results from the oscillating movement of the valve slide ( 9 ). A microprocessor ( 12 ) switches the pilot valves ( 10 ) and thus ensures the start-up and stabilization of the oscillation of the pistons ( 1 ).

Vor dem Start werden die Kolben (1) mit der Feder (7) im unteren Totpunkt gehalten. Nun werden die Kolben (1) durch Drucköl, das auf die Ölkolben (2) wirkt, in Richtung zum oberen Totpunkt beschleunigt. Die Zeitspanne der Druckölwirkung wird so gewählt, daß die Kolben (1) jene Geschwindigkeit erreichen, die zur Bewirkung der gewünschten Kompression der Verbrennungsluft erforderlich ist.Before starting, the pistons ( 1 ) are held in the bottom dead center by the spring ( 7 ). Now the pistons ( 1 ) are accelerated towards the top dead center by pressure oil, which acts on the oil pistons ( 2 ). The time period of the pressure oil effect is selected so that the pistons ( 1 ) reach the speed that is required to effect the desired compression of the combustion air.

Zum Öffnen des Druckölanschlusses (13) werden die Vorsteuerventile (10) vom Mikroprozessor (12) elektrisch betätigt. Dadurch werden die Ventilschieber (9) mit Drucköl beschleunigt. Sie schwingen aus der Ruhestellung und öffnen den Druckölanschluß (13). Dann schwingen die Ventilschieber (9) infolge von Druckölwirkung auf die Hinterseite zurück. Sie werden mit Druckölwirkung auf die Vorderseite abgebremst und bleiben in Ruhestellung stehen.The pilot valves ( 10 ) are actuated electrically by the microprocessor ( 12 ) to open the pressure oil connection ( 13 ). This accelerates the valve spool ( 9 ) with pressure oil. They swing out of the rest position and open the pressure oil connection ( 13 ). Then the valve slides ( 9 ) swing back due to the effect of pressure oil on the rear. They are braked with the effect of pressure oil on the front and remain at rest.

Die Öffnungszeit des Druckölanschlusses (13) wird durch entsprechende Wahl der Steuerzeiten der Vorsteuerventile (10) und der damit gegebenen Wahl des Umkehrpunktes der Ventilschieber (9) bestimmt. Liegt der Umkehrpunkt der Ventilschieber (9) knapp hinter dem Öffnungspunkt des Druckölanschlusses (13), so ergibt sich eine kurze Öffnungszeit. Liegt der Umkehrpunkt weiter dahinter, so ergibt sich eine längere Öffnungszeit.The opening time of the pressure oil connection ( 13 ) is determined by a corresponding choice of the control times of the pilot valves ( 10 ) and the choice of the reversal point of the valve spool ( 9 ). If the reversal point of the valve slide ( 9 ) is just behind the opening point of the pressure oil connection ( 13 ), the opening time is short. If the reversal point is further behind, the opening time is longer.

Nun erfolgt die Zündung und die Kolben (1) werden durch den Verbrennungsdruck in Richtung zum unteren Totpunkt beschleunigt. Mit einem oder mit mehreren Sensoren (11) wird die Kolbengeschwindigkeit gemessen. Dann öffnen die Ventilschieber (9) den Druckölanschluß (13) und bremsen dadurch die Kolben (1). Der Öffnungszeitpunkt und die Öffnungsdauer des Druckölanschlusses (13) werden aus der Kolbengeschwindigkeit vom Mikroprozessor (12) nach gespeicherten Kurvenfunktionen berechnet. Durch die Auswahl aus verschiedenen Kurvenfunktionen werden Luftdruck, Öldruck, Temperatur und andere Einflüsse berücksichtigt.Now the ignition takes place and the pistons ( 1 ) are accelerated towards the bottom dead center by the combustion pressure. The piston speed is measured with one or more sensors ( 11 ). Then the valve spools ( 9 ) open the pressure oil connection ( 13 ) and thereby brake the pistons ( 1 ). The opening time and the opening time of the pressure oil connection ( 13 ) are calculated from the piston speed by the microprocessor ( 12 ) according to stored curve functions. By selecting from various curve functions, air pressure, oil pressure, temperature and other influences are taken into account.

Der Öffnungszeitpunkt wird so gewählt, daß die Kolben (1) ihre Bewegung in der Nähe des unteren Totpunktes umkehren. Die Öffnungsdauer wird so gewählt, daß die Kolben (1) nach der Bewegungsumkehr die für die nächste Kompression nötige Geschwindigkeit erreichen.The opening time is chosen so that the pistons ( 1 ) reverse their movement near the bottom dead center. The opening time is chosen so that the pistons ( 1 ) reach the speed required for the next compression after the reversal of movement.

Öffnungszeitpunkt und Öffnungsdauer des Druckölanschlusses (13) werden durch entsprechende Schaltzeiten der vom Mikroprozessor (12) geschalteten Vorsteuerventile (10) eingehalten. Die Ansteuerung der Schwingbewegung der Ventilschieber (9) erfolgt nach dem beim Startvorgang beschriebenen Schema.The opening time and duration of the pressure oil connection ( 13 ) are maintained by appropriate switching times of the pilot valves ( 10 ) switched by the microprocessor ( 12 ). The oscillating movement of the valve slide ( 9 ) is controlled according to the scheme described during the starting process.

Durch Anordnung mehrerer parallel arbeitender Hydraulikventile (8) je Kolben (1) wird die Schaltgeschwindigkeit der Steuerung erhöht.The switching speed of the control is increased by arranging several hydraulic valves ( 8 ) per piston ( 1 ) working in parallel.

Bei gegenläufig arbeitenden Kolben (1) wird die Bewegung dadurch synchronisiert, daß ein Kolben als Führungskolben genommen wird und die Steuerzeiten des geführten Kolbens entsprechend korrigiert werden.In the case of pistons ( 1 ) working in opposite directions, the movement is synchronized in that a piston is used as the guide piston and the control times of the guided piston are corrected accordingly.

Zum Abstellen des Motors werden die Kolben (1) durch entsprechende Ventilsteuerzeiten im unteren Totpunkt angehalten.To switch off the engine, the pistons ( 1 ) are stopped at the bottom dead center by appropriate valve timing.

Da die Energie aus dem Verbrennungsdruck größer ist als die Kompressionsenergie wird bei diesem Vorgang Öl gepumpt.Because the energy from the combustion pressure is greater than the compression energy oil is pumped during this process.

Claims (7)

1. Freikolbenmotor, bei dem ein oder mehrere Kolben (1), die mit Hydraulikkolben (2) starr verbunden sind, in Zylindern entlang der Längsachse frei beweglich sind, dadurch gekennzeichnet, daß die Hinterseite der Kolben (1) zur Förderung der Verbrennungsluft verwendet wird und die Kolbenbewegung von elektronisch angesteuerten Hydraulikventilen (8) in Gang gesetzt und gesteuert wird.1. Free-piston engine, in which one or more pistons ( 1 ), which are rigidly connected to hydraulic pistons ( 2 ), are freely movable in cylinders along the longitudinal axis, characterized in that the rear side of the piston ( 1 ) is used to convey the combustion air and the piston movement is started and controlled by electronically controlled hydraulic valves ( 8 ). 2. Freikolbenmotor nach Anspruch 1, dadurch gekennzeichnet, daß je zwei Kolben gegeneinander arbeiten.2. Free piston engine according to claim 1, characterized in that two Work pistons against each other. 3. Freikolbenmotor nach einem der oberen Patentansprüche, dadurch gekennzeichnet, daß je Kolben (1) mehrere Hydraulikventile (8) parallel arbeiten. Dadurch wird die Ansprechzeit der hydraulischen Steuerung verringert.3. Free piston engine according to one of the above claims, characterized in that for each piston ( 1 ) a plurality of hydraulic valves ( 8 ) work in parallel. This reduces the response time of the hydraulic control. 4. Freikolbenmotor nach einem der oberen Patentansprüche, dadurch gekennzeichnet, daß die Kolbengeschwindigkeit von einem oder von mehreren Sensoren (11) gemessen wird und danach Wirkungsbeginn und Wirkungsdauer des Hochdrucköles auf die Hydraulikkolben (2) so bemessen wird, daß die Kolben (1) in Nähe des unteren Totpunktes ihre Bewegung umkehren und danach so beschleunigt werden, daß die gewünschte Kompression entsteht.4. Free-piston engine according to one of the above claims, characterized in that the piston speed is measured by one or more sensors ( 11 ) and thereafter the start and duration of action of the high-pressure oil on the hydraulic pistons ( 2 ) is dimensioned such that the piston ( 1 ) in Reverse their movement near bottom dead center and then accelerate so that the desired compression occurs. 5. Freikolbenmotor nach einem der oberen Patentansprüche, dadurch gekennzeichnet, daß die Ventilschieber (9) zur Einleitung des Steuervorganges aus der Ruhestellung in Richtung Öffnung des Hochdruckanschlusses (13) beschleunigt, danach bis zur Bewegungsumkehr gebremst und in die Gegenrichtung beschleunigt und danach bis zum Stillstand in der Ruhestellung wieder gebremst werden. Durch entsprechende Wahl der Beschleunigungs- und Verzögerungszeiten und damit des Umkehrpunktes der Ventilschieber (9) werden Wirkungsbeginn und Wirkungsdauer des Hochdrucköles auf die Hydraulikkolben (2) bestimmt.5. Free piston engine according to one of the above claims, characterized in that the valve slide ( 9 ) for initiating the control process accelerates from the rest position towards the opening of the high-pressure connection ( 13 ), then braked until the movement is reversed and accelerated in the opposite direction and then to a standstill be braked again in the rest position. Appropriate selection of the acceleration and deceleration times and thus the reversal point of the valve spool ( 9 ) determines the start and duration of action of the high-pressure oil on the hydraulic pistons ( 2 ). 6. Freikolbenmotor nach einem der oberen Patentansprüche, dadurch gekennzeichnet, daß die elektronische Berechnung der Ventilsteuerzeiten in Abhängigkeit von der Kolbengeschwindigkeit nach eingespeicherten Kurvenfunktionen erfolgt, wobei nach Öldruck, Luftdruck, Temperatur und nach anderen Einflüssen die entsprechende von mehreren eingespeicherten Kurvenfunktionen gewählt wird.6. Free piston engine according to one of the above claims, characterized characterized that the electronic calculation of valve timing depending on the piston speed after stored Curve functions take place, whereby according to oil pressure, air pressure, temperature and according to other influences, the corresponding one of several stored Curve functions is selected. 7. Freikolbenmotor nach einem der oberen Patentansprüche, dadurch gekennzeichnet, daß die Synchronisation der beiden gegenläufigen Kolben (1) elektronisch durch Korrektur der Steuerzeiten erfolgt, wobei die Steuerzeiten des geführten Kolbens entsprechend der tatsächlichen Bewegung des Führungskolbens korrigiert werden.7. Free-piston engine according to one of the above claims, characterized in that the synchronization of the two opposed pistons ( 1 ) is carried out electronically by correcting the control times, the control times of the guided piston being corrected in accordance with the actual movement of the guide piston.
DE19904024591 1990-08-02 1990-08-02 FREE PISTON ENGINE Withdrawn DE4024591A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE19904024591 DE4024591A1 (en) 1990-08-02 1990-08-02 FREE PISTON ENGINE
PCT/EP1991/001460 WO1992002730A1 (en) 1990-08-02 1991-08-02 Free-piston engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19904024591 DE4024591A1 (en) 1990-08-02 1990-08-02 FREE PISTON ENGINE

Publications (1)

Publication Number Publication Date
DE4024591A1 true DE4024591A1 (en) 1992-02-06

Family

ID=6411543

Family Applications (1)

Application Number Title Priority Date Filing Date
DE19904024591 Withdrawn DE4024591A1 (en) 1990-08-02 1990-08-02 FREE PISTON ENGINE

Country Status (2)

Country Link
DE (1) DE4024591A1 (en)
WO (1) WO1992002730A1 (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996033343A1 (en) * 1995-04-20 1996-10-24 Split Cycle Technology Limited Free piston engine
US5913290A (en) * 1995-05-02 1999-06-22 Kvaerner Asa Power plant
WO2000052314A1 (en) * 1999-02-22 2000-09-08 Caterpillar Inc. Method of operating a free piston internal combustion engine with high pressure hydraulic fluid upon misfire or initial start-up
DE19606040C2 (en) * 1996-02-19 2000-09-28 Univ Dresden Tech Fast-switching hydraulic valve
WO2001038706A1 (en) 1999-11-24 2001-05-31 Mannesmann Rexroth Ag Free-piston engine
WO2001088352A1 (en) 2000-05-19 2001-11-22 Mannesmann Rexroth Ag Free piston motor
DE10033443A1 (en) * 2000-07-10 2002-02-07 Mannesmann Rexroth Ag Free-piston motor for driving e.g. axial reciprocating machine, has valves in paths connecting high pressure and low pressure tanks, so that compression strokes of piston act on valves
US6863507B1 (en) 1999-11-24 2005-03-08 Mannesmann Rexroth Ag Generic free-piston engine with transformer valve assembly for reducing throttling losses
US7082909B2 (en) 2002-04-25 2006-08-01 Deutsches Zentrum Fur Luft- Und Raumfahrt E.V. Free-piston device with electric linear drive
US8596230B2 (en) 2009-10-12 2013-12-03 Sturman Digital Systems, Llc Hydraulic internal combustion engines
US9206738B2 (en) 2011-06-20 2015-12-08 Sturman Digital Systems, Llc Free piston engines with single hydraulic piston actuator and methods
US9464569B2 (en) 2011-07-29 2016-10-11 Sturman Digital Systems, Llc Digital hydraulic opposed free piston engines and methods

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2469279A (en) 2009-04-07 2010-10-13 Rikard Mikalsen Linear reciprocating free piston external combustion open cycle heat engine
US8887690B1 (en) 2010-07-12 2014-11-18 Sturman Digital Systems, Llc Ammonia fueled mobile and stationary systems and methods

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1480101B1 (en) * 1964-11-25 1969-11-06 Citroen Sa Andre Drive block consisting of a free-flight piston internal combustion engine and hydraulic pump of a hydrostatic transmission
DE2307760B2 (en) * 1973-02-16 1975-03-27 Jacques Henri Le Vesinet Jarret Hydraulic spring
DE2217194B2 (en) * 1971-04-09 1977-09-29 Jarret, Jacques Henri, Le Vesinet; Jarret, Jean Marie Baptiste, Fourqueux; Yvelines (Frankreich) FREE-PISTON ENGINE
DE2648958C2 (en) * 1976-10-28 1983-02-17 Karl-Heinz 8722 Sennfeld Fengler Hydraulic piston pump driven by a free piston internal combustion engine

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1332799A (en) * 1970-10-12 1973-10-03 Riekkinen As Hydraulic power unit including a hydraulic pump operated by a free piston internal combustion engine
US4307999A (en) * 1979-06-25 1981-12-29 Pneumo Corporation Free piston engine pump including variable energy rate and acceleration-deceleration controls
US4382748A (en) * 1980-11-03 1983-05-10 Pneumo Corporation Opposed piston type free piston engine pump unit
EP0085800B1 (en) * 1982-02-10 1987-05-13 Pneumo Abex Corporation Opposed piston type free piston engine pump unit

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1480101B1 (en) * 1964-11-25 1969-11-06 Citroen Sa Andre Drive block consisting of a free-flight piston internal combustion engine and hydraulic pump of a hydrostatic transmission
DE2217194B2 (en) * 1971-04-09 1977-09-29 Jarret, Jacques Henri, Le Vesinet; Jarret, Jean Marie Baptiste, Fourqueux; Yvelines (Frankreich) FREE-PISTON ENGINE
DE2307760B2 (en) * 1973-02-16 1975-03-27 Jacques Henri Le Vesinet Jarret Hydraulic spring
DE2648958C2 (en) * 1976-10-28 1983-02-17 Karl-Heinz 8722 Sennfeld Fengler Hydraulic piston pump driven by a free piston internal combustion engine

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6029616A (en) * 1995-04-20 2000-02-29 Split Cycle Technology Limited Free piston engine
WO1996033343A1 (en) * 1995-04-20 1996-10-24 Split Cycle Technology Limited Free piston engine
US5913290A (en) * 1995-05-02 1999-06-22 Kvaerner Asa Power plant
DE19606040C2 (en) * 1996-02-19 2000-09-28 Univ Dresden Tech Fast-switching hydraulic valve
GB2362191A (en) * 1999-02-22 2001-11-14 Caterpillar Inc Method of operating a free piston internal combustion engine with high pressure hydraulic fluid upon misfire or initial start-up
WO2000052314A1 (en) * 1999-02-22 2000-09-08 Caterpillar Inc. Method of operating a free piston internal combustion engine with high pressure hydraulic fluid upon misfire or initial start-up
GB2362191B (en) * 1999-02-22 2002-11-13 Caterpillar Inc Method of operating a free piston internal combustion engine with high pressure hydraulic fluid upon misfire or initial start-up
WO2001038706A1 (en) 1999-11-24 2001-05-31 Mannesmann Rexroth Ag Free-piston engine
US6863507B1 (en) 1999-11-24 2005-03-08 Mannesmann Rexroth Ag Generic free-piston engine with transformer valve assembly for reducing throttling losses
WO2001088352A1 (en) 2000-05-19 2001-11-22 Mannesmann Rexroth Ag Free piston motor
DE10033443A1 (en) * 2000-07-10 2002-02-07 Mannesmann Rexroth Ag Free-piston motor for driving e.g. axial reciprocating machine, has valves in paths connecting high pressure and low pressure tanks, so that compression strokes of piston act on valves
US7082909B2 (en) 2002-04-25 2006-08-01 Deutsches Zentrum Fur Luft- Und Raumfahrt E.V. Free-piston device with electric linear drive
US8596230B2 (en) 2009-10-12 2013-12-03 Sturman Digital Systems, Llc Hydraulic internal combustion engines
US9206738B2 (en) 2011-06-20 2015-12-08 Sturman Digital Systems, Llc Free piston engines with single hydraulic piston actuator and methods
US9464569B2 (en) 2011-07-29 2016-10-11 Sturman Digital Systems, Llc Digital hydraulic opposed free piston engines and methods

Also Published As

Publication number Publication date
WO1992002730A1 (en) 1992-02-20

Similar Documents

Publication Publication Date Title
DE4024591A1 (en) FREE PISTON ENGINE
US3380388A (en) Automatic control system for concrete pump
DE2539878C2 (en) Thermodynamic machine with closed circuit
DE644695C (en) Injection molding machine for plastic masses
SE9604342L (en) Method and apparatus for eliminating piston rod rust when starting a pneumatic motor
AT24045B (en) Starter control for double-acting four-stroke explosive engines to be started with compressed air.
DE841951C (en) Arrangement for actuating the hydraulic drive of injection molding machines for plastic masses
DE886827C (en) Free piston internal combustion engine
US3588292A (en) Device for regulating,by reflux through the inlet-valve,the sucked flow for reciprocating compressors
DE162187C (en)
WO2012062290A2 (en) Internal combustion engine
DE1003986B (en) Four-stroke internal combustion engine
DE446689C (en) Control of the combustion gases from the fuel engine serving as a fuel gas generator
DE416115C (en) Machine for generating compressed gases
DE837863C (en) Liquid extinguishing chamber with differential pump piston
SU453327A1 (en) HYDRAULIC PRESS DRIVE
DE1451952B2 (en) Device for reversing the direction of rotation of an internal combustion engine
DE51869C (en) Composite steam engine with oscillating pistons
GB884388A (en) Improvements in or relating to hydraulic drives
DE381809C (en) Starting and stopping device for the drive machine of compressors when a minimum and a maximum pressure are reached
DE333423C (en) Two-stroke deflagration machine with controllable inlet slots and stepped pistons
DE524646C (en) Device for starting diesel engines
DE1500511C (en) Hydrostatic gears, in particular for machine tools
DE53906C (en) Control for the exhaust of gas engines influenced by the pressure in the working cylinder
DE156813C (en)

Legal Events

Date Code Title Description
OM8 Search report available as to paragraph 43 lit. 1 sentence 1 patent law
OP8 Request for examination as to paragraph 44 patent law
8139 Disposal/non-payment of the annual fee