Classifications

• • 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
  • F01B31/00—Component parts, details, or accessories not provided for in, or of interest apart from, other groups
  • F01B31/22—Idling devices, e.g. having by-passing valves
  • F01B31/24—Disengagement of connections between pistons and main shafts
• • 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
  • F02B73/00—Combinations of two or more engines, not otherwise provided for
• • 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
  • F02B75/16—Engines characterised by number of cylinders, e.g. single-cylinder engines
  • F02B75/18—Multi-cylinder engines
  • F02B75/22—Multi-cylinder engines with cylinders in V, fan, or star arrangement
  • F02B75/225—Multi-cylinder engines with cylinders in V, fan, or star arrangement having two or more crankshafts

Definitions

• the present invention relates to internal combustion engines comprising at least a first crankshaft linked to an output shaft of the engine by means of a first rotation link, a second crankshaft connected to the output shaft of the engine by means of a second rotating link, and more particularly relates to the engines intended to equip motorized ultralights (ULM), autogyros, amateur light aircraft, hovercraft, air-boats, hydrofoils, drones, or the like.
• ULM motorized ultralights
• a primordial problem in this type of application in the event of an engine malfunction is to ensure, despite everything, the safety of pilots and possible passengers, and to allow them to reach a stopping point with maximum safety.
• Another problem is to avoid the destruction of equipment due to incidents or accidents caused directly or indirectly by engine malfunctions. Consequently, a motorization for such applications must be very reliable and robust, and yet remain light, powerful, and practical.
• the object of the present invention is to provide a solution to the above problems and to provide other advantages. More specifically, it consists of an internal combustion engine comprising at least a first crankshaft linked to an output shaft of said engine by means of a first rotation link, a second crankshaft linked to said engine output shaft by means of a second rotary link, characterized in that said first rotary link is reversible and comprises a first drive wheel linked in complete rotation to said first crankshaft by means of a first obstacle link capable of transmitting a engine effort from said first crankshaft towards said output shaft and capable of breaking, during a malfunction resulting in immobilization of said first crankshaft, under an effort less than or equal to the effort required to immobilize said first crankshaft, and in that said second rotating link is reversible and includes a second drive wheel linked in a c complete rotation of said second crankshaft via a second obstacle connection capable of transmitting an engine force from said second crankshaft to said output shaft and capable of breaking, during a malfunction resulting in immobilization of
• the engine according to the invention can operate despite the immobilization of at least one crankshaft, by means of a controlled rupture of the link connecting the output shaft to the immobilized crankshaft or which is intended to immobilize at following a malfunction, for example a piston tightening.
• the output shaft which is integral with the propeller may continue to rotate despite the immobilization of a crankshaft, under the effect of the engine torque supplied by the non-immobilized engine crankshaft (s).
• the ULM or the like can win a safe landing point, instead of being subject to the hazards of gliding flight in the case of ULM or falling in the case of a gyroplane for example.
• the engine according to the invention can advantageously comprise more than two crankshafts.
• the engine according to the invention comprises at least a third crankshaft, a third rotation connection, a third drive wheel, a third obstacle connection.
• This characteristic relates to an engine with three crankshafts each linked to the output shaft by means of an obstacle connection capable of breaking. In the case of immobilization of any of the crankshafts, the engine continues to operate on the other two crankshafts, the immobilized crankshaft being disengaged from the output shaft by the rupture of the connection by obstacle concerned.
• Figure 1 shows an exploded partial front view of the exemplary embodiment of an engine according to the invention.
• Figure 2 shows a partial sectional view along line I-I of Figure 1.
• FIG. 3 shows an enlarged detail of FIG. 2, more particularly relating to the obstacle connection.
• FIGS. 4 and 5 show the same isolated element in FIG. 2, in perspective for FIG. 4 and in rear view for FIG. 5.
• FIGS. 6 and 7 show the same isolated element in FIG. 1, in perspective for FIG. 6 and in side view for FIG. 5.
• the engine 1 represented in FIG. 1 is an internal combustion engine with three cylinders 2, 3, 4 placed in a star (not shown), two stages, in particular suitable for equipping the machines set out above. Each cylinder 2, 3, 4 corresponds to a respective crankshaft 5, 6, 7.
• the engine 1 shown in FIGS. 1 and 2 comprises a first 5 crankshaft linked to an output shaft 8 of the engine by means of a first rotation link, a second 6 crankshaft linked to the output shaft 8 of the engine by means of a second rotary link, a third 7 crankshaft linked to the output shaft 8 of the engine by means of a third rotary link.
• FIG. 2 corresponds to a section according to the first cylinder 2, along line II of FIG. 1, but may correspond equally to the similar cut according to any one of the other two cylinders 3 and 4.
• the output shaft 8 is the drive shaft on which the engine power is recovered, and carries a propeller (not shown) in the example.
• the first rotating link is reversible and includes a first 11 drive wheel. completely linked in rotation to the first 5 crankshaft by means of a first obstacle connection capable of transmitting an engine force from the first 5 crankshaft to the output shaft 8 and capable of breaking, during a malfunction resulting in immobilization of the first 5 crankshaft, under an effort less than or equal to the effort required to immobilize the first 5 crankshaft.
• the second rotation link is reversible and comprises a second drive wheel linked in complete rotation to the second 6 crankshaft by means of a second obstacle connection capable of transmitting an engine force coming from the second 6 crankshaft towards the 'output shaft 8 and capable of breaking, during a malfunction resulting in immobilization of the second 6 crankshaft, under a force less than or equal to the force required for the immobilization of the second 6 crankshaft.
• the third link in rotation is reversible and includes a third drive wheel 26 connected in complete rotation to the third 7 crankshaft by means of a third obstacle link capable of transmitting an engine force from the third crankshaft to the output shaft 8 and capable of breaking, during a malfunction resulting in immobilization of the third crankshaft 7, under a force less than or equal to the force necessary for the immobilization of the third crankshaft 7.
• the first, second and third rotational connections are advantageously gear connections, as shown in FIGS. 1 to 3.
• the first 11, second 25, and third 26 drive wheels are engaged on a fourth 12 driven wheel linked in complete rotation to the output shaft 8, by any known means, by example by a key 30, as shown in FIGS. 1 and 2.
• the motor shown in FIGS. 1 and 2 advantageously allows an assembly in which the first 11, second 25, third 26 drive wheels, and fourth 12 driven wheel are substantially or exactly located in the same plane, the first 11 , second 25, and third 26 drive wheels respectively secured to the first 5, second 6, and third 7 crankshafts being engaged on the circumference of the fourth 12 wheel driven at an angular offset, for example equal to 120 ° in the case of the three-cylinder star engine, as shown in FIG. 1.
• the engine according to the invention has a significant longitudinal functional compactness, a simplicity and a rationality of the transmission of the movement, allowing a reduction of the bulk and the engine weight, and increased reliability.
• each of the three obstacle connections has the function of transmitting the engine force from the crankshaft concerned to the output shaft while allowing the rotational connection between this crankshaft and the output shaft to break. immobilization of this crankshaft as a result for example of a tightening of the piston actuating the crankshaft concerned.
• Several pistons can actuate the same crankshaft, the optionally.
• the tightening of a piston allows the engine to operate on the two remaining cylinders, by disengaging the immobilized crankshaft, which gives the engine according to the invention great operational safety.
• the first obstacle connection comprises at least one shear pin 13.
• the pin 13 can be replaced by a shear key (not shown) or the like, and its dimensions and material will advantageously be chosen, when the pin or pins constitute the only obstacle of the obstacle connection, so that the section or sections of shear, two in number in the example of the figures, resist the transmission of the maximum engine force of the crankshaft concerned in normal engine operation, and will also be chosen so that the plug (s) shear under a force less than or equal to the force required to immobilize the crankshaft concerned when the engine is running.
• the first obstacle connection comprises a first shear pin 13, or the like, and advantageously further comprises a first drive stop 14 capable of transmitting the engine force from the first crankshaft to the output shaft.
• the first stop 14 has the essential purpose of preventing the engine force from being transmitted by the shear pin, and that the shear pin is used only when the crankshaft provides resistance to the output shaft.
• the dimensions and the material of the anchor will be chosen so that it can shear under an effort less than or equal to the effort required to immobilize the first crankshaft when the engine is running, the ankle in front Obviously withstand the maximum resistant force that the crankshaft can oppose to the output shaft in normal engine operation. It should be noted that in FIG.
• the first drive stop 14 advantageously comprises at least one asymmetrical tooth 15 held in engagement in a hollow housing 16 of complementary shape, by means of the pin 13, key, or the like, of shear, as shown in FIG. 3.
• the asymmetrical tooth 15 preferably comprises a first face 17 capable of transmitting the motor force and a second face 18 opposite the first face 17, making it possible to avoid engagement of the asymmetrical tooth 15 in the recess 16 in case of ankle 13 breaking, key, or the like, shearing.
• the first face 17 is preferably included in a plane passing through the axis of rotation of the crankshaft concerned so that the force transmitted is perpendicular to the face 17, and the second face 18 of the asymmetrical tooth 15 advantageously has a appropriate inclination, as shown in FIG. 3, so that the tooth 15 is driven out of the housing 16 when the pin 13 breaks, and cannot be reintroduced therein.
• the first drive stop 14 advantageously comprises, as shown in FIG. 3, a plurality of teeth 15 forming a first ring extending in a first plane perpendicular to a longitudinal axis of the first crankshaft.
• the teeth of the crown are preferably identical to that described above.
• the plurality of teeth allows the pressure to be distributed evenly circumferentially on the first crankshaft and the first drive wheel, and to reduce the dimensions of this drive stop 14 accordingly.
• the teeth of the crown can be produced on the wheel 11, the corresponding recessed housings then being produced on the crankshaft 5, or vice versa.
• Figures 4 and 5 show the wheel 11 alone, isolated from the connection, on the scale of Figure 3, and highlights the crown of asymmetric teeth 15, comprising 12 teeth.
• FIGS. 6 and 7 show the crankshaft 5 alone, on the scale of FIG. 2, and highlights the ring of housings 16 complementary to the asymmetric teeth 15, comprising 12 housings. It will also be noted in these figures the presence of a diametral hole in the cylindrical part 20 to accommodate the pin 13, and a groove to accommodate an elastic ring 24 as will be explained below.
• the first drive wheel 11 has a bore 19 allowing it to be centered on a cylindrical part 20 of circular section at the end of the first crankshaft 5 so that the wheel 11 can rotate around of the crankshaft 5, when the ankle 13 has broken.
• the above relates equally to the first, second, or third link in rotation.
• the engine 1 will have any suitable known means intended to reduce the friction of a drive wheel on the associated crankshaft in the event of breakage of the connection by obstacle, for example mounting of the wheel on the crankshaft via 'one or more bearings (not shown) capable of additionally allowing possible movement in translation of the drive wheel on the crankshaft, or by means of a ring or bearing 22 (not shown).
• the bearing material can be chosen so as to withstand the pressure due to the transmitted forces and for its ability to reduce friction, for example bronze.
• the end of the cylindrical part of the crankshaft will be provided with any means necessary for retaining the drive wheel on the crankshaft in the event of the connection being broken by obstacle, for example a ring or elastic ring 24 as shown in the figure 3.
• All the drive wheels and the driven wheel 12 will advantageously be enclosed in a sealed and lubricated casing 21, as shown in FIG. 2, in order to ensure lubrication of the rotational connections between the crankshafts and the output shaft , when these connections require such lubrication, such as for example metal gear connections.
• This lubrication can advantageously be carried out by bubbling or the like.
• the lubrication of the rotating links can advantageously be used in order to lubricate if necessary the rotation of the drive wheel on the crankshaft in the event of the link breaking by obstacle.
• the casing 21 has been removed in FIG. 1 in order to show the rotational connections.
• the rotational connections between the crankshafts and the output shaft can, alternatively and depending on the use of the engine, be achieved by means of chains or belts for example.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
• Valve Device For Special Equipments (AREA)
• Valve-Gear Or Valve Arrangements (AREA)
• Transmission Devices (AREA)
• Electric Propulsion And Braking For Vehicles (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=9497780

Family Applications (1)

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• 1996
  • 1996-11-14 FR FR9614109A patent/FR2755728B1/fr not_active Expired - Fee Related
• 1997
  • 1997-11-13 NZ NZ335349A patent/NZ335349A/xx unknown
  • 1997-11-13 AT AT97945914T patent/ATE247224T1/de not_active IP Right Cessation
  • 1997-11-13 CZ CZ991706A patent/CZ170699A3/cs unknown
  • 1997-11-13 EP EP97945914A patent/EP0938627B1/de not_active Expired - Lifetime
  • 1997-11-13 WO PCT/FR1997/002035 patent/WO1998021458A1/fr active IP Right Grant
  • 1997-11-13 PL PL97333406A patent/PL333406A1/xx unknown
  • 1997-11-13 CA CA002271093A patent/CA2271093C/fr not_active Expired - Fee Related
  • 1997-11-13 US US09/101,639 patent/US6095110A/en not_active Expired - Fee Related
  • 1997-11-13 AU AU51248/98A patent/AU732318B2/en not_active Ceased
  • 1997-11-13 DE DE69724139T patent/DE69724139T2/de not_active Expired - Lifetime
  • 1997-11-13 CN CN97199734A patent/CN1238026A/zh active Pending
  • 1997-11-13 ES ES97945914T patent/ES2205259T3/es not_active Expired - Lifetime

Non-Patent Citations (1)

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